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Service Manual - TT

1. ase 5790A 1606 Figure 6 7 A6 Wideband PCA Option 03 6 31 5790 6 32 Table 6 9 1 HMS Support eae Notes CAPACITOR R05R CAP TA 4 7UF 20 25V 807644 C2 C7 8 C10 CAPACITOR ROSA CAP POLYES 0 01UF 10 50V 715037 12 13 16 24 25 CAPACITOR R05A CAP POLYES 0 47UF 10 50V 697409 CAPACITOR R05A CAP POLYES 1UF 10 50V 733089 CAPACITOR R05A CAP POLYES 0 047UF 10 50V 820548 E CAPACITOR FILM POLYESTER 0 1UF 109 50V 5MM 649913 LS RADIAL TAPE LEEREN CAPACITOR 330 596 50 697441 15 17 CAPACITOR R05R CAP CER 82PF 2 50V C0G 714857 2 1 DIODE BA483 A52A DIODE SI PIN 35V 100MA DO 7 806646 DIODE 1 4448 A52R DIODE SI 75V 150MA DO 35 203323 JM1 TP2 3 JUMPER R05R JUMPER WIRE NONINSUL 0 200CTR 816090 HEADER 2 100 2 HEADER 2 ROW 100CTR RT 12 PIN 806935 BM LUN re E IRA RO5A TRANSISTOR SI NPN 40V
2. 3 56 10 2 20 2 50 2 100 2 200 2 1 2 2 2 10 2 20 2 50 2 100 2 200 2 500 2 700 2 Error Calibration and Verification 3 Verification Table 3 16 Wideband Verification Test Record cont If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatness Error 90 90 Days Absolute Error Spec Measured Absolute 7 3 2 V 5790 Range JEH Test Voltage S rv o respe rv o foo m rv sev om o oro respe a o oro _ rv sev om o oro _ rv sev sowie om o _ om 2 rv az om 2 rv mes os ors wt rv os _ m rv o m rv eav em o e rv o _ rv o _ pv uv ore ow fos m sv wv mm wm sv uv mm ome m sv wv wem om m sv wv mew ome sav wv mes om D sav wv om sav wv oor
3. 7 KS K1 K2 K 8105 C107 106 J a 6102 C150 T 21 7 24 5 ETRANSFER 45470 280805005 FLUKE USA R CR15 MEL U103 2 R16 E FA ____ __ C nut WT ry uo jj LJ 25 oj 934 i fo lal oie S E amp E kee Figure 7 8 A10 Transfer PCA 5790A 1610 Schematic Diagrams 7 INPUT SWITCHING Et Ri PROT IN 93479 450 5790A 7692 PROTECTION CKT U32 U33 IN SEL 3 0 BOT ES U34 5 91 7 23 1 C22 R3 4 PROT IN ANN SHEET 3 480v 390K CR3 T P 6 10 JPAD10 491 6 97 0 DESIGNATOR GND RLHCOM TESTPOINTS CHASSIS GUARD 7V 220V DIVIDER HI 920 OUT TRANSFER SWITCH 921 OUT u22 A3 OUT u23 A4 IN u24 036 0101 lt 4 1 1 3 3 4 4 CRS 1N4448
4. ua 142 282 y L 5790 1603 Figure 6 5 Analog Motherboard 6 23 5790 6 24 Table 6 7 A4 Digiital Motherboard Part E s enda 4 CAPACITOR ROSR CAP TA 10UF 20 35V RO5R CAP TA 10UF 20 35V 816512 sas CAPACITOR FILM POLYESTER 0 1UF 10 50V 5MM 649913 pee capacron cap Powvesorurcamasone wmm CAPACITOR RO5A CAP CER 6800PF 5 100V COG 16710 1 2 cma mmm ws RWETAL LBEMTUBULAROVAL HEAD mem connector ace connacconerrexey mem s 7 7 WASHER WASHER FLAT STL 093 219 020 WASHER FLAT STL 093 219 020 306415 2 8 14 CABLE ACCESSORY CABLE ACCESS TIE 4 00L 10W 75 172080 oa sssi H517 17 SPACER ROUND 187 LAL SNAP TOP BROACH ROUND 187 L AL SNAP TOP BROACH 2069 HEADER ms HEADERHEADER Lm HEADER HEADER ROW Ta H CONNECTOR 1 ROW 156 INCH 844717 CENTERS LOCKING RAMP RIGHT ANGLE TIN 5 PIN BULKPurchased Item J51 52 HEADER HEADER 1 ROW 156CTR 3 PIN 380022 FIBER OPTIC FIBER OPTIC TRANSMITTER 1MBD 822155 FIB
5. 48 halb fil imi oim eom Q3 C D 010 0 00 DD 0 DOG DDD De DU oo o DDD DDD eo e m i VACDSPL DM256X26 120 78 59 024 75V 6 022 75 LRN u23 BLANK BLANK 1 BLANK BLANK TP21 CLK DLK STRB STRB SFRB STRB SERIAL SERIAL SERIAL SERIAL SRTDDATA D our ESH U16 12 D IN OUT IN D IN 917 20__ G49 20 681 EL 17 525 eee 92 918 42 651 i 683 295 40 019 920 16 see Q20 16 beT Mdb 920 921 39 2118 99 sot 025 922 14 654 922 5102 37 022 525 i2 325 924 924 12 638 9104 35 024 0251 11 697 9251 11 699 102 34 Q28 226 GS a26 10 690 426 927 _ 411 027 9 691 107 32 927 028 8 660 012 928 8 9092 gros 31 928 9287 St 915 429 7 893 109 30 929 30 1 8 662 978 27 1614 5 694 8110 27 1044 930 415 See AER AE I 015 Q31 7 832 BTS 031 16 2 3 664 8
6. 5 8 Test Step AD8255 A D 8255 sss 5 9 Test Step ADSELFTEST A D Internal Selftest 5 10 Test Step ADZEROS A D 7 5 11 Test Step ADNULLDAC A D Null DAO 5 12 Test Step ADDAC A D DAC Output 5 13 Test Step CHOPPER A D Chopper 5 14 Test Step PROT Protection 5 15 Test Step OVLD Overload sse Contents continued 5 16 Test Step ZEROS 5 17 Test Step DIVIDERS Input Dividers 5 18 Test Steps X2 2V through X2 2MV 5 19 Test Step MATCH Sensor Match 5 20 Test Step XFREQ Frequency Measuring 5 21 Test Step LOOPFILT Sensor Filter 5 22 Test Step WOVLD Wideband Overload 5 23 Test Steps W7V through W2 2MV Wideband 2 2 mV Range 5 24 Test Step WFREQ Wideband Frequency Measuring 5 25 Test Step WLOOPFILT Wideband Sensor Filter 6 List of Replacable RR 6 1 IntrOQUCOTI cic 6 2 How to u Lu Tunas
7. RS 232 C TT Rear Panel CPU Digital Section Detailed Circuit Description Digital Power Supply Assembly A19 35 Power Supply eit tei 12 V Power Supplies 3 oo eire nete e bee od 35 V Power Supply ass 75 Power Supply etcetera opposes e retener e 35 V and 75 V Shut Down Circult CPU Assembly 20 iiie IER DH ERE Power Up and Reset Circuit esses Clock Generation eie eM eres Watchdog RTT ter ed Address Decoding and DTACK Data Acknowledge Interrupt Controller seen ROM Read Only Electrically Erasable Programmable Read Only Memory EEPROM pcm 2 20 2 1 5790 Service Manual 2 2 2 90 2 97 2 99 2 100 2 101 2 102 2 103 2 104 2 105 2 106 2 107 2 108 2 109 2 110 DUART Dual Universal Asynchronous Receiver Transmitter Clock Calendar Circuit Clock Filter Circutt CPU to Rear Panel Interface CPU to Front Panel Interface sese Fro
8. 20 A20 CPU Figure 6 6 71 5790 6 72 Table 6 22 21 Rear Panel UO Part Des Description T 668 5 CAPACITOR CAPACITOR ROSR CAP CER 330PF 5 50V C0G_ 697441 21 22 24 28 pd 649913 13 C40 42 C48 49 LS RADIAL TAPE EAM C70 CAPACITOR CAPACITOR CAP TAGBUF 209418V 193615 12 s R05R CAP TA 10UF 20 25V 714774 gt 50 CAPACITOR ELECTROLYTIC TANTALUM 1UF 697417 2 a LS RADIAL TAPE CONNECTOR CONN MICRO RIBBON REC PWB 24 POS 851675 E i CONNECTOR CONN D SUB PWB 25 845214 HEADERHEADER 1ROW 100CTR4PIN HEADER 1 ROW 100CTR 4 PIN 631184 a vals Ral PIN LATCHING BULK F OD BRASS SWAGE 062 PANEL MP3 4 SPACERSPACER SWAGE 250 RND BR4 40 234 SPACER SWAGE 250 RND BR 4 40 234 99910 2 wor pepAceRsARERSWAGE 1 BAG MYLAR STATIC SHIELD OPEN 0031 10 00 14 00 680967 R1 RESISTOR A52R RES MF 1K 1 0 125W 100PPM 168229 RESISTOR A52R RES CF 200 5 0 25W 441451 RESISTOR A52R RES MF 332 1 0 125W 100PPM 192898 RESISTOR A52R RES CF 1K 5 1W 641073 EN RESISTOR A52R RES MF 200 1 0 125W 100PPM 245340 2 2 eiee aE ae T C we LSTTL 75160 1C LSTTL OCTAL GPIB XCVR WIOPEN COL 75160 C LSTTL OCTAL GPIB XCVR
9. AMPLIFIERS CHOPPER MEASURE DAC PROTECTION INTERRUPT BINDING POSTS ATTENUATORS AND PROTECTION MODULE RMS TYPEN SENSOR CONNECTOR CHOPPER FLOWCHART ADJUST DAC MEASURE MEASURE INPUT M1 DAC M2 DISPLAY MEAS elu002 eps Figure 2 1 Functional Block Diagram 5790 KEYBOARD ASSEMBLY CPU CONTROL ASSEMBIY FRONT PANEL DISPLAY FRONT PANEL INTERFACE BUS ASSEMBLY MEASUREMENT DISPLAY A19 DIGITAL POWER SUPPLY A21 REAR PANEL IEEE 488 EEPROM ASSEMBLY DUART m REAR PANEL INTERFACE BUS gt FIBER OPTIC CABLE UNGUARDED GUARD CROSSING GUARDED REGULATOR ANALOG ASSEMBLIES GUARD CROSSING ASSEMBLY elu003 eps Figure 2 2 Digital Section Block Diagram 2 8 2 6 2 7 Theory of Operation 2 System Interconnect Detailed Circuit Description System Interconnect Detailed Circuit Description The motherboard assembly contains the Digital Motherboard assembly A4 and the Analog Motherboard assembly
10. e an SS 7 elu050 eps Figure 4 2 Rear Panel Removal 4 5 5790 Service Manual 4 10 Rear Panel Assembly Access Refer to Figure 4 3 during the following procedure 1 Remove screws that secure the Rear Panel assembly housing 2 Gently pull the rear panel housing from the Rear Panel 3 Allow the rear panel housing to lay flat on the work surface by removing the two ribbon cables from the Rear Panel board 4 Remove the Jack screws for each connection on the rear panel housing then gently lift the Rear Panel assembly out from the housing REMOVE S Q 9 26 E G le S 27 lt 1 REMOVE THE JACK SCREWS SEPARATE THE REAR PANEL CIRCUIT BOARD FROM THE METAL HOUSING elu051 eps Figure 4 3 Rear Panel Assembly Access 4 6 Maintenance 4 Access Procedures 4 11 Front Panel Removal and Installation Refer to Figure 4 4 during the following procedure l 2 Remove 5790 bottom covers Remove the single screw at top of the Front Panel and six hex screws the front handle sides Then grasp both handles and gently tilt the Front Panel down and away from the mainframe disengaging the green power button Position the Front Panel on its handles in front of the instrument
11. CIO 2 0 9 0 0 0 K CAUTION PIN 1 056 874859 E y woe ZE ieee 152 acci C U gt uU lt GC k lt gt 5 de lt 27 2 ca 22 o 5790A 1617 Figure 7 15 A17 Regulator Guard Crossing PCA 7 41 5790 17 0 TO 417 95V K 1N4007 29 30V TO 32 63V P117 Designator LT10850K 30 FRIR 19 eam OLLI 203 909 0 CD e 202 Co C EN Oot TOM 1O0QOMOO m v C IY e uuu lu OG Oo IO oiog 00 101010 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 F OT 900 000 0900 v7 eG PS O 00 O c Kd coo sib 00 SP SF lt COGO OO 222522 22222222 17 S COM 20 20 FRi COM 22 30 FR1 T 1N4002 T COM CR4 7 144007 R2 2 67 1 317HVH U1 c3 05UF CER FRIR COM 0 17 03 TO 18 7V CR15 07 LT10330K 7 29 30 TO 432 63V 05 317HVH 30 FR2R FR2 184002 5 55 TO 48 40V U11 LM317K tL 620 1OUF 5 LH COM c5 amp
12. 752 40 2 RR ooo Q 10 1 Null Detector Fluke 845A 0 1 0 1 pV resolution resolution 10 V DC Reference Standard Fluke 732A or B 10 V Uncertainty 1 ppm 1 Throughout this manual whenever 845 is referenced 845AB or 845AR is applicable 2 The 5700A must contain software Rev E or higher Rev E and higher software includes the Xfer Off function which is required during AC calibration of the 5790A main input 3 7 5790 Table 3 2 5700 DC Characterization Test Record Part 1 5790A Calibration DC 845A Final Null 5700A Error Display Indication to obtain Requirement V uV Characterized Nominal Output Table 3 3 5700A DC Characterization Test Record Part 2 Characterized 5440B 6 V Output Characterized 5440B 2 V Output 5790A Calibration DC 845A Final Null 5700A Error Display Indication to obtain Requirement V uV Characterized Nominal Output Calibration and Verification 3 Periodic Calibration Warning Some steps in following procedure involve the calibrator outputs at lethal voltages Use extreme care not to touch any exposed conductors 1 Warm up all equipment for the period specified in the manufacturer s manual The 720A and 752A should be allowed to soak in the lab environment for at least 8 hours prior to use for best results 2 Selfcalibrate the 720A and 752A in accordance with their instruct
13. e ertt e Calibrating Wideband AC 2 Characterizing AC Calibrating Wideband Input Gain at 1 kHz Calibrating Wideband Input Service Calibration orm nen erroe ren a aA re ary Xfer Offset Adjustment ene Wideband Amplifier Rolloff Adjustment Mises REPE Verifying the Main Input INPUT 1 or 2 Verifying AC DC Difference for Regions I and 220 mV through 1000 V Verifying Absolute AC Error for Region IV 70 mV through 700 mV Verifying Absolute AC Error for Region II 2 2 V through 1000 V Verifying Absolute AC Error for Region V 2 2 mV through 22 Verifying the Wideband AC 3 1 5790 Service Manual 3 32 Wideband 1 kHz Gain VerificatioN 7V 2 2V 700 mV and 70 mV Ranges siis onte hassan LR 3 33 WIDEBAND 1 kHz GAIN VERIFICATION 22 mV RANGE 3 34 Wideband Gain Verification 10 Hz to 500 3 35 Wideband Flatness 3 2 Calibration and Verification
14. Operating Input 250 mV to 500 mV Maximum Non Destructive Input 50V rms General Specifications Warm up 30 Relative Humidity Operating sssrinin 45 to 50 C 75 to 45 C 95 to 30 C Storage lt 95 non condensing Altitude enn rete 3 050 meters 10 000 feet Non Operating 12 200 meters 40 000 feet Temperature 0 C to 50 C Calibration eee 15 C to 35 SIORAGG AT 40 C to 70 C EMI RFI Complies FCC Part 15 Subpart B Class B VDE 0871 Class B ESD EIA PN 1361 NI aed ANSI C62 41 1980 Category A MIL T 2880D paragraph 3 13 3 Size Height nd bmc 17 8 cm 7 in standard rackmount 1 5 cm 0 6 in Width reete ttt teet d 43 2 cm 17 in Depth PES 63 cm 24 8 in Maximum Power Requirements n dieta hen eae erede 95 VA With Wideband Option 120 VA Weight 24 kg 53 Ib With Wideband 24 5 kg 54 Ib Line e ccce nnn tns 47 Hz to 63 Hz 10 of selectable line voltages 100 V 110 V 115 V 120 V 200 V 220 V 230 V 240 V Complies with UL1244 and IEC 348 1976 and IEC 1010 and CSA C22 2 No 231 and ANSI ISA S82 Remote Interfaces RS 232 IEEE 488
15. 1 9 Proper Power Cord 1 10 Do Not Operate in Explosive Atmosphere 1 11 Do Not Attempt to Operate if Protection may be Impaired 1 12 Do Not Remove the Cover unless Qualified 1 13 Do Not Service Alone essere 1 14 Use Care when Servicing with Power On 1 15 Sp ecIfICAtlOnS Theory of Operation T 2 l Introduction eem metr t e Pe eere o FERE es 2 22 S790ACOVEEVIEW b IR ED E AEEA iS 2 3 Functional Block Diagram Discussion sees 2 4 Digital Section OvervIew nennen 2 5 Analog Section Overview eren 2 6 System Interconnect Detailed Circuit Description 2 7 Digital Motherboard Assembly 4 2 8 Transformer Assembly 22 2 9 Analog Motherboard Assembly A3 2 10 Rear Panel I O Assembly 21 402 40 0 2 11 Rear Panel Power Supplies sse 2 12 Rear Panel Digital Control sese 2 13 Clock Regeneration Circuit essere 2 14 IEEE 488 GPIB Interface sese 2 15 R 232 C Interface ec OPER ERE 2 16 Rear P
16. 6 28 a eme mem TIE Renee T YR ates pr wes aeaea T 11 INDUCTOR 44NH 15 2ADC 25MOHM SHIELDED AXIAL BUL 249110 1 INDUCTOR 82NH 10 1 79ADC 29MOHM SHIELDED AXIAL 256289 BULK L3 L14 TP1 7 TP9 JUMPERROSR JUMPER WIRE NONINSUL 0 200C TR 816090 TP11 17 JM1 TP2 3 peser weesenmmswesumu m es menanospaer neu een mum pr ere eewweewenmmon 2 e ssemesemwmemmcem hes smemsmswossowm pen smemsmswomeemon m 2 r pr SI 1 1 TO 39 BULK E s I 92 ZEN M MIT OHMS 300MW DMOS LOW CAPACITANCE TO 72 BULK 58202 TEE s fas see RESISTOR A52R RES MF 1K 1 0 125W 100PPM pem R55 R80 R123 R5 R3 4 R6 R95 RESISTOR A52R RES MF 10K 1 0 125W 100PPM 168260 13 R131 R4 R1 3 R5 R9 R12 R15 E RESISTOR A52R RES MF 24 9 1 0 125W 100PPM 298657 1 R9 R144 145 RESISTOR A52R RES MF 15 1 0 125W 100PPM 3 R18 R62 RESISTOR A52R RES MF 499K 1 0 125W 100PPM es 2 Taa pr List of Replacable Parts 6 Parts Lists R21 RESISTOR A52R RES MF 442K 1 0 125W 100PPM 375956 R25 R29 R35 RESISTOR A52R RES MF 49 9 1 0 125W 100PPM 305896 EN R28 R117 R119 RESISTOR A52R RES CF 2M 5 0 25W R139 R9 R37 RESISTOR CARBON COMPOSITION 51 5
17. 1 2 1 7 23 Transfer PCA ere a ZE VAR ENT EX SERT 7 24 Precision Amplifier 0 7 29 A10A2 High Voltage Protection 7 30 A10A3 High Gain Precision Amplifier 7 31 ATS A D Amplifier iiri e RR IER A eT 7 32 PENG DONEC DG N 7 36 A16A1 DAC Filter PCA 7 40 A17 Regulator Guard Crossing 40 7 41 ALS Filter EET O EEEN RO iets 7 44 A19 Digital Power Supply PCA 2 20 7 47 A20 CPUPCA aeree epe 7 50 AZI Rear Panel orca REIR e ER ee I ERR eR 7 56 A62 Input Block Assembly 0 90 0 22 7 59 A16HR6 DC Amp Hybrid On the A16 7 60 16 Reference Hybrid On the A16 7 61 7 1 5790 7 2 Schematic Diagrams 7 5790 1601 Figure 7 1 1 Keyboard 7 3 5790 R2 i 9 CR6 CR7 ND 1 INSTALLED LEDIB LED2A LED2B LED3B LED4A LED4B COLUMN COLUMN COLUMN COLUMN COLUMN COLUMN COLUMN COLUMN
18. 1 485355 1 4935 35UNREG CR11 gx CR12 1 4935 1 493535 06 35_AC_2 A10 MPSA42 RESETLiC29 CR33 1N4007 5790A 1019 1 of 2 Figure 7 17 A19 Digital Power Supply PCA cont 7 48 Schematic Diagrams 7 12 FAN 12 CR20 1N4933 144933 12 0 _2 CR22 1 400 92 12 1 46 7 2 U3 CR25 CR26 51 3052 4 IN L CR27 CR28 88404 83510 d X CR35 2 11276 m 5790 1019 2 of 2 2 2 u Figure 7 17 A19 Digital Power Supply PCA cont 7 49 5790 co LE Be _ Cilo ud U aa 1 cei Ci28 L 1 4 TP5 TPIO 155 ka T a Loud emu CT44 43 145 4 7 50 Figure 7 18 20 CPU 5790 1620 Schematic Diagrams POWER UP AND RESET CIRCUITRY RESETE RESE TL7705A VREF U6 8 SHT1 CRS SHT2 P220 C26 SHT4 C6 0 1UF V RESET PULSE IS 195 mSEC EXCEPTION VECTOR PULLUPS Y2 TOMHZ B OSCILLATOR DESIGN OPTION ADDRESS DECODERS amp DTACK GENERATOR 022
19. A16 DAC Assembly Block 1 Wideband Assembly Block 5790A Calibration Memory Organization sese eee ee eee DC Source Characterization Setup Part 1 a as DC Source Characterization Setup 2 DC Source Characterization Setup Part 3 esses 5790A DC Calibration Test Worksheet for 2 V to 1000 V AC Calibration Points Worksheet for 60 mV to 600 mV AC Calibration Points 5790A AC Calibration Test Millivolt Range Bootstrapping Wideband Calibration Source Characterization Part 1 Wideband Calibration Source Characterization Part 2 Gain Calibration Setup for 70 mV and Above sss WIDEBAND Input Flatness Calibration Test Setup Location of R27 Transfer and C20 and C24 Wideband Worksheet for AC DC Error 70 mV through 700 mV Ranges Worksheet for AC DC Error All Other Worksheet
20. G D u N D IN OUT ug 337 7905 Uia POWER PINS TABLE IN OUT c32 GND REF DES 4 TUF 25V Uii 14 us 8 us 02 28 us 21 987250 4 USS 21 u27 14 5LH RLHCOM LHCOM C36 F 4 7 25U 4 7 250 11 L126T i 1 1 i 1 1 i 1 i i 1 1 i 1 i 1 1 1 i H 1 i 1 1 1 i i 1 1 1 cis 4 7 7254 4 T 28U 5790A 1006 4 of 4 Figure 7 5 A6 Wideband PCA Option 03 cont 7 21 5790 22 I 9 Ting 15 TLJ Jor P 9 E o Oram 702 e e c ree I O gt Nj IN cot L lt 22 Cy EN c e 9 22 mn pa 2 C Be c 62 5790 1696 u4 CA3086 04 PIN 16 GND
21. elu021 eps 3 13 5790 INPUT 1 5790 UUT DUAL BINDING EXT GUARD POST ADAPTER SENSE HI E SENSE LO COAXIAL TEE Use HEAVY BRAID 500 COAXIAL CABLE J I 00 GUARD GROUND 5700A CALIBRATOR WITH 5725A AMPLIFIER EXT SENSE INT GUARD STRAP FROM GUARD TO GROUND elu020 eps Figure 3 5 5790A DC Calibration Test Setup Calibration and Verification 3 Periodic Calibration 6 Press the Cal softkey The display changes to Prev Full Calibration Cal ENTER the ambient temperature Menu Temp 23 0 15 to 35 elu023 eps Note The following display appears if the 5790A has not been turned on for at least 30 minutes If you know that warmup requirements are met for example if you briefly turned off the power press YES do it to override The 5790A has been on only 27 minutes Do u still want to calibrate it NO cancel YES do it la 4 La La La La elu024 eps 7 Enter the ambient temperature using the numeric keypad the numbers appear below the keys and press the ENTER key Or to accept the default of 23 0 C just press ENTER Proceed with Cal Sel
22. 5 25 Test Step WLOOPFILT Wideband Sensor Filter 5 1 5790 5 2 Troubleshooting Introduction 5 1 Introduction This chapter describes the processes that take place during power up self tests and during diagnostics By understanding the diagnostics test processes error messages can provide more information Run self diagnostics by pressing UTIL MENUS followed by Diags softkey During all diagnostic procedures all the input relays are open The instrument is disconnected from the outside world There are no diagnostic procedures that require an external input When a diagnostic fault occurs during remote operation the instrument logs an error and then continues halts or aborts depending on the setting of the remote command DIAGFLT When a diagnostic fault occurs during front panel operation the instrument halts displays the error and prompts the user to continue or abort diagnostics While the instrument is in the halted state the hardware is setup per the test configuration This allows a technician to probe the hardware 5 2 Main CPU A20 Power Up Tests The following list identifies the test name and process associated with error codes for Main CPU tests e Error Code 2100 20 Main CPU ROM Checksum 16 bit CRC check e Error Code 2101 A20 Main CPU RAM read write pattern test e Error Code 2110 20 Main CPU Watchdog test that Watchdog goes off
23. A32 3 6B864MHZCL BRESET 5790A 1002 1 of 4 DECODING AND TIMING CIRCUITRY SPARES CLOCK REGENERATION CIRCUITRY Figure 7 2 A2 Front Panel cont Schematic Diagrams 7 KEYBOARD SCANNER CIRCUITRY DOTMATRIX DISPLAY FILAMENT CIRCUITRY 41 13 13 24 5 4 BELL t N7406DT KEYBDARD CONNECTOR TP40 45 41 92 ze ee LOUER 19 1 28 COLUMN 2 14 BOUT COLUMN 3 COLUMN N7408DT US TT 04 415 06 583 1 11 DOTMATFILAMENTH 052 215 1 022 CLK2 I 023 9 R36 PAL IMAGE 520 4 TPB TPS EPD7 EFDS f Te 5 FPD4 FPD3 2 1 93 10 LED LATCH 9 N74D6DT CD 1 BCX 17 CUTPUTFILAMENTA CUTPUTETLANEN f D51 60 GUTPUTFILAMENTB DS1 31 R4B 453 05 42 ENCODERINTR U3 8 ENGGBERCS 03 9 ENGODERRESET OUTPUT DISPLAY FILAMENT CIRCUITRY PAL IMAGE 5 1 C33 5790 1002 2 of 4 Figure 7 2 A2 Front Panel PCA cont 7 7 5790 33 TP32
24. N List of Replacable Parts 6 Parts Lists R12 R29 R34 RESISTOR CARBON FILM 100K 5 0 25W RADIAL TAPE 658963 3 R14 15 RESISTOR R05A RES MF 75K 1 0 25W 100PPM 851902 2 RESISTOR CARBON FILM 62K 5 0 25W RADIAL TAPE 713941 1 RESISTOR R05A RES CF 430 5 0 25W 817577 1 R18 19 R22 RESISTOR R05A RES CF 1K 5 0 25W 780585 11 R24 26 R51 R70 71 R80 81 RESISTOR R05A RES MF 100 1 0 25W 100PPM 817627 1 RESISTOR METAL FILM 453K 1 0 125W 100PPM AXIAL TAPE 295709 1 RESISTOR VAR RES VAR CERM 10K 10 0 5W 285171 1 RESISTOR CARBON FILM 62K 5 0 25W RADIAL TAPE 713941 1 R30 R41 RESISTOR METAL FILM 1 37K 875369 2 196 0 125W 50PPM RADIAL TAPE RESISTOR METAL FILM 432 1 0 25W 50PPM RADIAL TAPE 875364 1 R33 R44 RESISTOR RO5A RES MF 200 1 0 25W 100PPM 820282 4 R61 62 R35 R54 56 RESISTOR 4 7 596 0 25 721571 4 RESISTOR A52R RES MF 69 8 1 0 125W 100PPM 306001 1 RESISTOR METAL FILM 909 1 0 25W 100PPM RADIAL TAPE 820308 1 RESISTOR RO5A RES CF 200 5 0 25W 810390 1 RESISTOR A52R RES MF 1 82K 1 0 125W 100PPM 293670 1 RESISTOR RORA RES CE 470 596 0 25 854567 1 RESISTOR RO5A RES MF 15K 1 0 25W 100PPM 866702 1 RESISTOR RO5A RES MF 3 83K 1 0 25W 100PPM 821827 1 R60 R63 RESISTOR R05A RES MF 12 1K 1 0 25W 100PPM 927454 2 R101 RESISTOR 5 5 200 5 0 25 681841 1 R103 RESISTOR A52R RES MF 1 43K 1 0 125W 25PPM 447995 1 R105 RESI
25. 0 2 WB Input Protection 1 A TO Transfert 2 A10AI Precision Amplifier 3 10 2 HV Protection 244 4 4 0 0 enne 4 A10A3 High Gain Precision Amplifier PCA 5 6 7 ATIS A D Amplifier 16 DAC PE us tener NEEDED UIN Ud DUE CO UM 6 52 AIGAT DAC Filtet EE 18 A17 Regulator Guard Crossing 6 19 A18 Filter PCA e CP 6 20 A19 Digital Power Supply 6 65 6 21 A20 CPU PCA TP 6 22 A21 Rear Panel PCA eon Un eR Pe RR aa ee RR viii Figure 1 1 qm US bee e List of Figures Dimensions oe re Ee ro RR Pest erc Fd eeu Ce oiee Functional Block Diagram sess Digital Section Block Diagram sss sese RS 232 Connector ssrin ret Pn e CPU Assembly Block Diagram essen A10 Transfer Assembly Block Diagram eese Divider Network Simplified Chopper Circuit Block Diagram A15 A D Amplifier Block
26. 6 60 EHS _ CHH E fase EHS EHS EHS List of Replacable Parts 6 Parts Lists CRS 8 5 5 CR3 CRT m CR21 C ERI 1 TP12 LRR 5 2 ORO 0 GL 752 NOILnVO y 2 09 CR36 GUARD CROSSING REGULATOR ASSY 874859 REV 5790A 1617 Figure 6 17 A17 Regulator Guard Crossing PCA 6 61 5790 6 62 Table 6 19 18 Filter Ref Des Description t emer Sw 1 10 17 CAPACITOR FILM POLYESTER 0 22UF 5 50V 5MM 747519 3 LS RADIAL TAPE LEE CAPACITOR CAP AL 6800UF 20 25V 782466 g CAPACITOR CAP AL 1000UF 20 50V SOLV PROOF 782391 CAPACITOR ELECTROLYTIC AL 2200UF 20 25V SOLV 782383 2 PROOF 27X16 5MM RADIAL BULK CAPACITOR ELECTROLYTIC ALUMINUM 330UF 816785 2 20 100V 16 5X27MM 7 5MM LS RADIAL BULK CAPACITOR ROSA CAP AL 220UF 20 25V SOLV 816793 1 PROOF C12 C22 CAPACITOR ELECTROLYTIC ALUMINUM 22UF 817056 2 20 35V 5MM LS LOW PROFILE RADIAL TAPE 16 CAPACITOR CAPACITOR CAP ALS300UF 20 50V 782458 CAPACITOR PY U CSS PROOF 816843 S eee 747493 1 20 50V SOLVENT PROOF 16X25 RADIAL BULK CAPACITOR R05A CAP POLYES 1UF 10 50V 733089 CR1 2 CR4 5 DIODE UES1303 A52R DIODE SI 150V 5A AXIAL 523720 CR8 CR10 CR12 1
27. La 4 10 Nothing has been saved in nonvolatile memory yet To make calibration valid you need to store the constants Set the rear panel CALIBRATION STORE switch to ENABLE Press the Store Cal Consts softkey Calibration is complete For information about printing calibration reports refer to Chapter 7 of the 5790A Operator Manual 11 If you decide not to store the updated constants press the DONE with softkey A menu warns you that if you quit at this point without storing the constants the updated constants will be discarded If you verify that you want to discard the constants the 5790A copies the stored set of constants into the active constants memory Figure 3 1 illustrates how calibration constant groups are manipulated 3 18 Calibrating the Wideband AC Option The following procedure is a part of periodic calibration only if a 5790 03 Wideband Option is installed in your 5790A If you are replacing or have repaired the Wideband assembly perform the Wideband Amplifier Rolloff Adjustment as described in the Service Calibration part of this chapter before calibration You calibrate the WIDEBAND input in four major steps elu034 eps 1 Perform the main input calibration first 2 Characterize the AC source a 5700A with Wideband option and associated attenuators cable and connectors 3 Calibrate the WIDEBAND input gain 4 Calibrate the WIDEBAND input flatness Table 3 7
28. R2 91 J72 5790A 1003 HFBR1522 8 of 3 i NOT 1 INSTALLED Figure 7 3 A3 Analog Motherboard PCA cont 7 13 5790 SA G DELTA PATCH ONLY NUS MP3 MP 4 H6 H7 RED BAND THIS END MPIO p 4220 M 5 HS 5790A 1604 Figure 7 4 A4 Digital Motherboard PCA 7 14 Schematic Diagrams 7 LINE SELECT SWITCHING TO TRANSFORMER PRIMARY POWER SWITCH TO TRANSFORMER PRIMARY B 1 5 LH AC2 16 2 5 LH AC 5 3 5 LH CT 17 4 5 5 COM 4 GUARD 17 5 1 18 17 S 2 19 8 17 S CT 20 R4 3 68 CB 2 6800PF 5 FR1 AC2 NOTES UNLESS OTHERWISE SPECIFIED GUARD 1 ALL RESISTORS ARE IN OHMS ALL CAPACITOR VALUES ARE IN MICROFARADS 15 CT 15 2 10 15 1 11 0 2 1 GUARD K 12 30 FR2 2 13 30 FR1 ACI MPS 14 30 FR1 AC2 gt 15 18 FRI MP5 5790A 1004 16 18 FRI AC2 1 of 2 Figure 7 4 A4 Digital Moth
29. STON TEMPS gt gt IM C lO 54100 19 21 23 25 27 MER VIEW REF S16 OF 6 8 mu gt 60 100 O S27 s25 VE g OF MICROFARADS 5790A 1001 Figure 7 1 A1 Keyboard PCA cont 7 4 Schematic Diagrams 7 53 C44 5790 1602 Figure 7 2 2 Front Panel PCA 5790 Des gnator TESTPOXNTS OUTPUT DISPLAY CONTROL CIRCUITRY ua 50 T5V uz GND DOTMATRIX DISPLAY CONTROL CIRCUITRY CEL cer 81 DPRENAO R WL R WR 750 BMSYL BUSYR INTL INTR 5 CEL GER t DPRENA 2130 FPWRITES RAWL R WR AOL AOR L4S__OD GAC REFRESH BUSYD BUSYL BUSYR EPAZ 45 UDCA GRIDCLK INTL INTR EEA A2R GRIDDATA 45 ODEA FRAT DEL OER ASE ASR US ASL L N8E080 60 __ 2 FPA12 21 50 ABL ABR 1 00 FPDTACK AOL aor 4
30. gt me ow fros me nes ro we fros w m me ow w m aw aw _ w m m mw v e e m ms e w m Tes ww e m m Tes ww n e w m m mw n e mo wwe Ta la 15 w m me wow os __ w m me m m 220 wm __ __ w m mo mw v __ __ mo wm a m m e 20 2000 tome t 9 fa Js 220 200 0 fo 114 220 2000 sowiz 06 56 Js 115 220 2000 2 198 56 Nose 116 emo oor 27 4 sooo vue z 4 eoo ki 9 4 Js o 3 47 5790 Service Manual Table 3 13 Test Record for Main Input Verification cont gt 5 8 9 48 945 9 lt S c 5225 gt o BE Pj 569 9 27528 los 25 3 9855 03 873 8 8 d 92 ooo sao wo e n o T O lt gt Ru 2 lt lt lt lt 1000 0 0 100 2 1000 0 1 2 ES 0 Era kHz 1000 0 0 20kHz kHz 1
31. 55544 V COMPARATOR VW R75 330K 5LH 8 fa 5082 2836 Cor R85 a21 56544 _ T 8144 i5 L 111 21 22 100 V V 18K 94 100PF 8143 VVV 5082 2836 1 RANGE COMP 3 2 U13 4 393 0227 12 SHT 3 013 383 2N2219A 144448 2N2385A R74 1N4448 8681 2 COLA 895 Bv 57909 40965 RMS SEC COL2 OUT 48 Le 51 6111 3 32k 392 17 S 5 51 21 5 SHT 3 DE o P106 2 1 113 141 5 8 458 R142 536 51 BF Q 23 52 iac ASAL 13 YCC 14 ASE U21 6 SHT 3 4021 15 SHT 3 115 2 22 U21 9 SHT 3 1121 12 SHT 3 57 865 15 COUNTER ig VEE DIU N EN DIUZ1 FILT COUNTER OUT ig sa GND 24 21 2 5790 1006 Figure 7 5 Wideband PCA Option 03 cont 7 19 5790 U25826 11 GND S ARE RLY U IN OU
32. 6 3 Manual Status 6 4 Newer Instruments ierit Rete een e e Ree 6 5 Service ERECTO 6 6 Parts au su 7 Schematic Diagrams 7 1 Appendices A Glossary of AC DC Transfer Related Terms A 1 B ASCII and IEEE 488 Bus Codes B 1 C Calibration Constant 1 5790 2 5 DO goth see X EO cm NE List Tables Title Page CPU Memory CPU Interrupts Priorities and Front Panel Memory Control Lines for the Keyboard LEDS sse Unregulated Supplies from the Filter Assembly Regulated Supplies from the Filter Assembly Regulated Outputs from the Regulator Guard Crossing Assembly Inguard CPU Memory ener enne enne Inguard CPU Equipment Required for 5790A DC Characterization 5700A DC Characterization Test Record Part 1 5700A DC Characterization Test Record Part 2 Equipment Required f
33. lt 4 6 4 11 Front Panel Removal and Installation 4 7 4 12 Display Assembly Removal and Installation 4 7 4 13 Keyboard Assembly Removal and Installation 4 7 4 14 Analog Assembly Removal and Installation 4 8 4 15 Digital Assembly Removal and Installation 4 8 4 16 Power Transformer Removal and Installation 4 8 4 17 Hybrid Cover 4 9 4 18 Installing a Wideband AC Module Option 03 4 9 4 19 Clearing Ghost Images from the Control Display 4 10 4 20 Replacing the Clock Calendar Backup Battery 4 11 4 2 Using Remote Commands Reserved for Servicing 4 11 4 22 Using the FATALITY and FATALCLR Commands 4 11 4 23 1 12 T aq aa RS R Troubleshooting 5 Introduction 5 2 CPU A20 Power Up Tests 5 3 A17 Guard Crossing Processor Power Up Tests 5 4 System Startup Tests 2 5 5 Diagnostic 165 RE 5 6 Test Step 8255 Motherboard 8255 5 7 Test Step DAC8254 DAC 8254
34. 6 54 List of Replacable Parts 6 Parts Lists 851 C3 C54 c R53 CHI e a 5790A 1616 Figure 6 15 A16 DAC PAC 6 55 5790 Table 6 17 A16A1 DAC Filter Ref Des Description Nis Qty Notes C1 C3 C5 CAPACITOR FILM POLYESTER 0 33UF 853903 3 20 50V RADIAL BULK C10 011 CAPACITOR POLYESTER 0 33UF 5 50V HERMETIC 876367 1 C12 13 C7 11 CAPACITOR SMR CAP CER 0 22UF 80 20 50V Y5V 1206 740597 9 1 2 14 CAPACITOR SMR CAP CER 100PF 10 50V COG 1206 740571 2 CR02 DIODE SI PN FJH1100 15V 150MA RADIAL LEAD PREP DO 853523 1 35 TAPE 1 RESISTOR CERMET 15K 1 0 25W 100PPM 1206 TAPE 769810 1 4 R2 RESISTOR SMR RES CERM 8 06K 1 125W 100PPM 1206 806356 1 4 R3 RESISTOR SMR RES CERM 61 9K 1 125W 100PPM 1206 821330 1 4 R4 RESISTOR SMR RES CERM 22K 5 125W 200PPM 1206 746651 1 4 R5 RESISTOR SMR RES CERM 11K 1 125W 100PPM 1206 867291 1 4 U1 BIPOLAR OP07C SMR IC OP AMP ULTRA LOW NOISE SOIC 783001 1 4 U2 BIPOLAR LT1007C IC OP AMP PRECISION LOW NOISE 782920 1 4 VR1 ZENER UNCOMP 1N965B 15V 5926 8 5MA 400MW DO 35 TAPE 266601 1 1 4Static sensitive note 6 56 List of Replacable Parts 6 Parts Lists ER REV 393276 C es LL RH 555 5790
35. gt 22 40 0 ata er sg lt HDL H AIONYA J9YLIO0A 5790A 1618 Figure 6 18 A18 Filter PCA 6 64 List of Replacable Parts 6 Parts Lists Table 6 20 A19 Digital Power Supply PCA Part Ref D Description t P U hay ty CAPACITOR CAP AL 470UF 20 160V 816835 CAPACITOR ELECTROLYTIC ALUMINUM 10UF 817064 1 20 160V 10 5X17 5MM 5MM LS RADIAL BULK CAPACITOR ELECTROLYTIC ALUMINUM 330UF 816785 1 20 100V 16 5X27MM 7 5MM LS RADIAL BULK C4 C9 CAPACITOR R05A CAP AL 10UF 20 63V SOLV PROOF 816843 s C5 C11 CAPACITOR R05R CAP CER 0 10UF 20 50V X7R 853650 4 20 C6 CAPACITOR CAP AL 10000UF 20 25V 816819 CAPACITOR CAP AL 6800UF 20 25V 782466 CAPACITOR RO5A CAP AL 2 2UF 20 50V SOLV PROOF 816868 CAPACITOR ELECTROLYTIC ALUMINUM 22UF 817056 20 35V 5MM LS LOW PROFILE RADIAL TAPE CAPACITOR CAP AL 22000UF 20 16V 822379 14 16 19 23 CAPACITOR CERAMIC 0 22UF 853648 7 20 50V X7R RADIAL TAPE CAPACITOR R05A CAP AL 100UF 20 16V SOLV 816850 1 PROOF CAPACITOR CAP POLYPR 0 047UF 10 630V 507 1 CAPACITOR FILM POLYPROPYLENE 0 047UF pe mp 1096 160V 13 5X9 7MM 10MM LS RADIAL BULK C24 25 CAPACITOR RO5R CAP CER 0 022UF 80 20 500V Z5U 2 acm _ CR8 CR16 CR21 DIODE 1N4007 A52R DIODE
36. press the STORE and keys 8506 14 Press the SET REF softkey 5790 15 Set the 5700 to 30 MHz adjust 5700 bring 8506 reading to 0 16 Press the NEW REF button on 5700 and dial in the 30 MHz correction for the A55 the attenuators and the current active calibration constant You do this by adjusting the 5700A knob for a 5700 error display of the same sign and magnitude as the total error entry 220 mV range at the bottom of Table 3 11 17 Raise the front of the guard cover and adjust C24 for a 5790A display of 3500 PPM 1000 PPM Use a Johanson 8777 tool or equivalent 18 Set the 5700A to standby 19 Replace the 10 dB attenuator with a 20 dB attenuator to give a total attenuation of 40 dB 20 Set the 5790A to the 70 mV range 21 Set the 5700 to 3 2 V at 1 kHz operate 22 The 5790A will read approximately 32 mV 23 Allow the A55 to stabilize and then press the STORE and OFFSET buttons on the 8506 DMM 24 Press the REF softkey the 5790A 25 Set the 5700A to 30 MHz and adjust the 5700 to bring 8506A reading to 0 26 Press the NEW REF button on the 5700A and dial in the 30 MHz correction for the A55 the attenuators and the current active calibration constant You do this by adjusting the 5700A knob for a 5700 error display of the same sign and magnitude as the total error entry 70 mV range at
37. 025 5 4 U25 18 SHT4 U31 21 5HTS U42 21 8HT5 U31 7 5HTS 025 9 5 4 U6 20 SHT1 U31 29 36 SHT5 ENTRENTET 1 U33 12 SHT4 U31 4 R51 SHTS IN 031 2 15 HT5 INIRCNTLZ IN 025 15 8HT4 PALG22V10 38hC BPSEFAZLINI 2 r o 23 3 JIN IPLO GCOUARTINTS IN 170 m IPLix EXDUARTINT IN 170 iPL2 BRPIEEEINTs 170 RDYZBSYL 170 KEYBRDINT 1 176 CLKCALINT 1 170 ROLNTs as PAL IMAGE INTERRUPT CONTROLLER UNLESS OTHERWISE SPECIFIED ALL RESISTORS ARE IN OHMS ALL CAPACITOR VALUES ARE IN MICROFARADS TESTPOINTS CLK GND 12V 5 12V GND TXDB RCVB SCLK CLKCALINT TRV ar an ao gt SPARES 5790 1020 1 of 5 Figure 7 18 A20 CPU PCA cont 7 51 5790 ADDRESS BUS lt 32 1 gt UPD27C4001 UPD27C4001 2 u5 20 SHT1 NVMCS 13 iO U6 7 U9 8 SHT1 U19 24 SHT3 U33 24 SHT5 U10 9 SHT1 09 8 1 019 28 U31 7 SHT5 RDY BS E7 SHT3 U27 15 SHT4 WRL 27 015 U33 1 SHT5 2094 NVMCS 22 U5 22 SHT1 RESET T MEM IMAGE 01 5 06 8 SHT1 P220 C26 SHT4 5082 UPD27C4001 CRB 6 7 09 8 RDL HT1 015 24 SHT2 U19 24 SHT3 5082
38. 15 CHR 280 28 28 28 30 2 30 FR2R 2 2 2 276 276 5 FR2 5 FR2 27 ER2 AGI 26A 28 26A FR2 COM COM 26 5 FRZ ACA 250 25A 25 254 25 5 FR2 1 240 24 2 24 5 FRIR 5 FRIR 24A 5 FR 2 230 23 23C 23 18 18 FRI 23 5 FR AC 220 22A 220 22A 5 FR 5 FRI 22A 18 AC2 1 216 21 ig 21 ER1R COM FRIR COM 21A 18 1 ACT 20 20 20 20 FR1 FRI 20 50 FRI 2 DAC SNS 196 19 DAC SNS 196 19 DAC SNS 30 30 FRIR 19A 30 FRI ACI DAC OUT 186 18 DAC HI 18 DAC OUT S 5 18 S 1 DAC OUT LO 176 17A DAC OUT LO 176 17 DAC OUT LO 174 170 7 16 164 16 16 166 164 156 18A BRE13 15 17 SR 15A 17 SR 150 15 17 SR BSRF13 140 14 BSRF13 17 58 34A 17 SR 146 14A 17 SR DIV OUT 130 13A DIV OUT 5 FRIR 136 17 S 13A 17 5 COM 13 13 17 S RCL 12 12 REL 126 12 17 126 tZA 17 S CT SDL 11 11 5 1 116 11 17 2 110 11 17 5 ACD CHOP LO 10A CHOP LO 18 FRI 19 104 17 5 106 104 17 S 1 CHOP HI 9 WB CHOP 5 9c 9A 44 SR 44 5 2 BRF6 BRF6 44 SR BA 44 ACI BSREG 7 76 44 S CT 70 44 8 FR1 COM 5 LHR ec 30 FRI
39. 30 FR2 supply This supply uses unregulated 30 FR2R supply from filter assembly consists of three terminal 39 regulator US with heat sink bypass capacitors C10 and C28 and protection diodes CR9 CR10 and CR12 Resistors R4 and 8 set the output voltage in the same manner as the 44 S supply Capacitor C12 improves ripple rejection Diodes CR9 and CR10 protect U5 against the input shorts while CR12 protects against the reverse voltage Guarded Digital Control Circuitry The Inguard CPU controls all the analog assemblies It communicates with the Unguarded CPU Assembly A20 through a serial fiber optic link The Inguard CPU is a Hitachi 63B03Y0 CMOS microcontroller U56 Support circuitry includes 32 K X 8 bit 32 KB of external CMOS ERROM 8 K X 8 bit 8 KB of external CMOS static RAM watchdog timer circuitry reset and power glitch detect circuitry a serial fiber optic link to the unguarded CPU a DUART dual asynchronous receiver transmitter to provide two serial interface channels and decoders and buffers to interface to the guarded digital bus Inguard CPU Memory Map Table 2 11 shows the memory map of the Inguard processor Table 2 11 Inguard CPU Memory Map 0000 through 0027 WIIIIISSIUNNIII Internal registers in the 6301 i 1 2 0040 through 013F Internal RAM in the 6301 256 Bytes T _ 2 30 2
40. INPUT N TEE 3 32 10 11 12 13 14 15 16 17 18 19 elu037 eps Figure 3 12 Gain Calibration Setup for 70 mV and Above Use the number keys to enter the value displayed on the 8506 DMM into the 5790A then press ENTER The 5790 will calibrate 7 V range and proceed to the 2 2 V range Apply 2 0 V at 1 kHz and press DO STEP as before Enter the value from the 8506A into the 5790A as before and press ENTER The 5790 will calibrate the 2 2 V range and step to the 700 mV range The 700 mV 220 mV and 70 mV ranges are done in a similar way just enter the exact value of the voltage as requested for each range and press ENTER Disconnect 8506 DMM after calibration of 70 mV range It is not accurate enough to calibrate the lower three ranges and it adds noise to the system If an accurate millivolt AC source is available use it to calibrate the 22 mV 7 mV and 2 2 mV ranges in the same manner as the other ranges Just enter the exact value when requested by the display and press ENTER If an accurate millivolt source is not available use a bootstrapping technique Record the 5790A reading on the range above the one to be calibrated and enter the recorded value as the EXACT VALUE when the display asks for it To calibrate the 22 mV range connect the equipment as shown in Figure 3 11 Apply 20 mV at 1 kHz
41. U9 11 SHT1 020 24 SHT3 BYPASS CAPACITORS NOTE PART MOS 27010 IS INSTALLED IN PCB FOR U15 U16 U17 AND 118 5790A 1020 2 of 5 Figure 7 18 A20 CPU PCA cont 7 52 Schematic Diagrams DATA BUS lt 15 0 gt ADDRESS BUS lt 52 0 gt U9 5 SHT1 13 27 SHT2 U27 15 SHT4 U33 1 8HT5 29 05 14 1 129 5 6 7 08 8 5 1 8 U15 24 SHT2 A01 02 AOS 04 o5 3 07 08 AGS 10 1 1 1 1 t 1 1 12 1 14 15 A16 919 WE est 30 52 24 DE IMAGE ADDITIONAL EPROM UPD27G4001 1 ips G j E6 A18 18 D Pom bad Pad Poa e tX Ot He CaN gt 1 2 4 5 A6 A7 10 e PROM2CS e o e gt RELY Cm A11 A12 A13 A14 A15 AIG PAN lona ihv jos t u5 17 SHT1 ADDITIONAL RAM 29 wt 226 3 9 1 16 24 U33 24 SHT55 12 15 14 15 17 08 5 010 14 SHT1 WRU u9 11 SHTT U16 24 SHT2 2 A10 Att A12 A13 15 A16 WE 651 52 DE IMAGE UPD27C4001 PROM2CS RAM2CS U5 16
42. CLRONTR Hi R 5 URD 22546 IMAGE WATCHDOG COUNTER EPROM RAM DUART 055 5002892 18 088 12 6835 17 084 TI 3 18 582 15 DEI 19 PEP INTR TXDA 22 HSREM RXDA RADB mig AE 8 x2 021 INPUT POWER FILTER 5Y 8 1103 10 10 108 5790 1017 5 I9 i i 2 of 2 Figure 7 15 A17 Regulator Guard Crossing PCA cont 7 43 5790 1618 DANGER HIGH VOLTAGE 5790A Service Manual fes G 183 ej o t 132 123A EX sa EE 3 0142 Figure 7 16 18 PCA 7 44 T Schematic Diagrams 15 30 FRIR 30 FRIR 7 0 5ASLO 30 FR1 AC1 30 FR1 AC2 TESTPOINTS NNN NNNMNN ENE eer 0 9 gt x mO m N OTECKO HEE 00040 02 0 0 AMI NMUtOTRN 00 00 Or Let x CRO TO 021010 C c TT LET Kwe T EEE Q c SF OX P O 0 51303 U
43. DI 70MV WB i Basic gain Ref DAC to input ratio IA_70MV_WB Rough gain input to A D ratio Appendices Calibration Constant Information Table C 60 Group WDC 220MV Gain Constants Wideband 220 mV Range DI 220MV WB 31 6228 Basic gain Ref DAC to input ratio IA 220MV WB 3 16228 Rough gain input to A D ratio Table C 61 Group WAC 220MV Flatness Constants Wideband 220 mV Range Table C 62 Group WDC 700MV Gain Constants Wideband 700 mV Range Basic gain Ref DAC to input ratio Rough gain input to A D ratio 5790 Table C 64 Group WDC 2 2V Gain Constants Wideband 2 2 V Range DI 2 2V WB 3 16228 Basic gain Ref DAC to input ratio IA 2 2V WB 31 6228 Rough gain input to A D ratio Table C 65 Group WAC 2 2V Flatness Constants Wideband 2 2 V Range Appendices Calibration Constant Information Table C 66 Group WDC 7V Gain Constants Wideband 7 V Range DI 7V WB Basic gain Ref DAC to input ratio IA_7V WB Rough input to A D ratio 5790
44. Diagnostic Tests Diagnostics start with the lowest level of hardware and work up to testing the basic functionality of each range Diagnostics are done using no calibration information This requires tests to have large tolerances In general you should repair errors in the same sequence that they were reported Two exceptions to this rule would be if all the digital tests failed 8255 and 8254 indicating that you should suspect the interface to guarded bus from Guard Crossing CPU or if massive analog tests fail check all the power supplies When the diagnostics are run in HALT mode i e either remotely via the DIAGFLT HALT command or from the front panel when a fault occurs the hardware is left in the test state to facility debugging by the technician The following list gives the test description for each step in the built in diagnostics routine Comments on each of the test steps are provided next in this chapter e 8255 Motherboard 8255 DAC6254 DAC 8254 AD6255 A D 8255 e SERIAL A D Serial Interface e ADSELFTEST A D Internal Self Test e ADZEROS A D Zeros ADNULLDAC A D NULL DAC ADDAC A D DAC Output CHOPPER A D Chopper e PROT Protection OVLD Overload ZEROS Zeros e DIVIDERS Test that 1000 V and 220 V dividers plugged in X2 2 2 2 V Range XZV 7 V Range X7VHF 7 V HF Range X22V 22 V Range X22VHF 22 HF Range X70V 70 V Range X220V 220 V Rang
45. Do Not Attempt to Operate if Protection may be Impaired Do Not Remove the Cover unless Qualified Do Not Service Alone Use Care when Servicing with Power On Specifications 5790 1 2 Introduction and Specifications 1 Introduction 1 1 Introduction The 5790A makes AC DC transfer measurements and accurate AC measurements from 700 to 1000 V 10 Hz to 1 MHz The optional 5790A 03 Wideband Module increases the 5790A frequency range to 30 MHz for inputs connected to the WIDEBAND 50 Type connector Accessory 57904 7001 allows the use of Fluke A40 or A40A Current Shunts with 5790A for making accurate AC DC current transfer measurements up to 20 A Refer to the 5790A Operator Manual for operating instructions use of the front and rear panel features remote programming and all other information for the operator This service manual is a maintenance guide for the 5790A The following topics are included e Theory of operation e Calibration e Performance testing Access procedures e Troubleshooting Parts lists e Schematic diagrams 1 2 Service Information Factory authorized service for 5790A is available at selected Service Centers For warranty or after warranty service contact the nearest Service Center for
46. Power Source The 5790A is intended to operate from a power source that will not apply more than 264 V AC RMS between the supply conductors or between the supply conductor and ground protective ground connection through the grounding conductor in the power cord is essential for safe operation Proper Fuse Usage To avoid fire hazard use only a fuse identical in type voltage rating and current rating as specified on the rear panel fuse rating label Do not use makeshift fuses or short circuit the fuse holder Grounding of the 5790A The 5790A instrument is a Safety Class I grounded enclosure instrument as defined in IEC 348 The enclosure 15 grounded through the grounding conductor of the power cord To avoid electrical shock plug the power cord into a properly wired earth grounded receptacle before connecting anything to any of the binding posts terminals or connectors protective ground connection by way of the grounding conductor in power cord is essential for safe operation Proper Power Cord Usage Use only the power cord and connector appropriate for the voltage and plug configuration in your country Use only a power cord that is in good condition Refer cord and connector changes to qualified service personnel Do Not Operate in Explosive Atmosphere To avoid explosion do not operate the 5790A an atmosphere of explosive gas Do Not Attempt to Operate if Protection may be Impaired If the 57
47. When Q2 conducts about 5 mA it turns on and starts to lower the voltage at comparator UI pin 9 The other input of the comparator at U1 pin 10 15 biased to 0 5 V When the input at U1 pin 9 drops below 0 5 V the comparator output turns on and drops the voltage on the output connector pin 11 to 0 V just as with the positive signal The comparator output signal at pin 11 passes to the Wideband board as the INP PROT signal and connects to a latch composed of two sections of gate package U27 Normal operation of the latch has INP PROT high and RESET high with the output at U27 pin 6 low The output at U27 pin 3 is high which gives a stable latch condition U27 pin 6 is also the CLR line which connects to relay driver U26 at pin 1 The output of U27 pin 8 is high When INP PROT drops low the output of the latch at U27 pin 6 and CLR goes high The high CLR signal turns off all outputs on the U26 relay driver and thereby drops out all of the input relays K1 K4 K9 and K10 With U26 pin 15 now high the output to digital line at connector P206 10C 15 also high The output of U27 pin 8 goes low and cause U27 pin 11 to go high and turn on FET Q11 pulls the INT low at connector P206 pin 1A The digital system recognizes that the WIDEBAND input was over 14 V when the INT line goes low at same time that the level at connector P206 10C went high The system is returned to normal operation when the RESET line pro
48. crs LF SW lt 3 0 gt 1N4448 9 1 U5 7 SHT 3 U5 9 SHT 3 XF CHOP LO GUARD MECCA N MICROFARADS 5790A 1010 1 of 40 Figure 7 8 A10 Transfer PCA cont 7 25 5790 DISABLEx FAR 030 1 400K CR11 1N4448 U32 6 U33 6 BOOT IN 01 44 BOOT U1 2 Z3 1 C22 CRe2 88 57904 7691 1N4448 1 CR20 1N4448 144438 s Sav 9 18 030 14 SW lt 3 0 gt vo 3 5 5790A 7695 6 lt 220MV 8 2UH 7 144448 2220MV 0 100 814 Ki U30 8 1N4448 CR13 N 144448 912 0104 FROM SCOM SHT 1 PRECISION AMPLIFIERS 7 26 Figure 7 8 10 Transfer cont 700MV VOUT 2 2V _ AMP OUT TP4 05 10 5790 1010 2 of 4 Schematic Diagrams 7 lt 3 0 gt SW 3 0 C107 m 022 5 0 1UF P210 as 96 4 COUNT 06444 5c COUNT o4 3 1N4448 G2 93 9104 IRFD420 3 1N4448 5 1 110 4 HGL SLOW FAST 3 5 17 144448 103 AD633 8 CR19 1N4448 1N4448 U102 4 T1013 1N4448 C9 YST 47N LM394N 7 3 8 104 47 0 14 7 OVL
49. o meme RND BR 140 125 H35 SLEEVING SLEEV POLYOL SHRINK 125 149450 0 2 0621D BLACK enan aso MOM rea 4 Fr wowe mmm CORE SORE TORO FERATE HHS 5790A 2021 WIDEBAND 5790A 2021 WIDEBAND CONNECTOR 89313 SLEEVING SLEEV POLYOL SHRINK 046 144410 0 05 BLACK 22 23 5725 2703 11 S725A 2703 M BINDINGPOS RED POST RED 88632 J2 whee wem rarasane rostan mmm 1 m sowersooersnowwe memaros mmm i Tanpa manen was 6 14 List of Replacable Parts Parts Lists W202 5790A 4406 CABLE WIDEBAND 893201 1 Consists of A22 A23 and A24 PCA s 6 6 15 5790 Service Manual H17 21 2 PL BRN 1 DRAN 3 CABLE DRAIN BLUE L DRAN 2 1 I8 DETAIL STEP INSTALL HARDWARE AND COMPONENTS AS SHOWN SEE DETAIL MP26 BLK H22 STEP III ZZ 35 40 LG STEP IV DETAIL DRAIN 1 BLK H11 16 2 PL CABLE DRAIN DRAIN 2 Ap H1 10 2 PL CABLE DRAIN BLU H1 10 4 PL H11 16 4 PL 23 MPG 50 LG 5 z 10 DETAIL Ill 5790a4204 eps Figure 6 2 A62 Input Block Assembly 6 16 Table 6 4 1 Keyboard List of Replacable Parts Parts Lists Part
50. 10 sna VIVG Lov sna ssdduaav elu005 eps iagram CPU Assembly Block D 4 2 igure F 2 15 5790 2 16 Table 2 3 CPU Glossary sn _ m ADCLCKCS Clock calendar U33 chip select A ____ Address ibe O C Theory of Operation 2 Digital Section Detailed Circuit Description Table 2 3 CPU Acronym Glossary cont seam 2 26 Clock Generation The clock generation circuit uses components Y 1 Y2 U3 U4 R4 R5 C8 C9 and ES The crystal Y1 along with the resistors capacitors and an inverter in U3 generates the 7 3728 MHz primary system clock CLK This system clock is used by the processor and is divided down by a binary counter U4 for clocks of 3 6864 MHz 28 8 kHz and 450 Hz The 450 Hz clock is used by the watchdog timer the 28 8 kHz 15 used by U6 in the decoding circuit and the 3 6864 MHz is used by the DUARTS and the clock filter circuit Jumper E5 allows for selection of the alternate oscillator Y2 as the system clock 2 27 Watchdog Timer The watchdog timer circuitry uses a 74HC4020 binary counter 011 to divide the 450 Hz from the clock generation circuit to produce interrupt DOGINTH signifying that the system may be locked up This interrupt is generated 1 14 seconds after the last 5790 Service Manual DOGCLR2 signal from interrupt controller U10 Therefore DOGCLR2 must occur mor
51. 5 50 TP29 TP37 U3 30 OTOBLANK 15 38 GRIDCLKO 05 36 05 34 U14 915 21 BLANK BLANK 05 57 23 PLK L 24 STRB STRB SERIAL SERTAL 05 40 506 _43 ip IN 5 D IN 5 our 2 42 i 2 0127 20 00017 DADP2 81 102 19 atlag Lig 00618 40 143 Qa 17 00019 BAM 38 04 94 2 16 00620 BAL2 38 los 15 BAL 9025 38 105 921 _15 00621 DAK2 37 06 BAR 90056 37 Jae 22 14 00022 PAJ2 56 07 0067 36 147 923 Lig 02623 55 924 7347 obea landas 025 BAG 38 oio D 90910 32 Jato 026 U14 23 DAF2 32 00011 32 011 027 012 08512 31 412 228 50 075 05815 as 029 aia 314 27 2 26 1415 DAB 20015728 045 QM die ULN5818EP ULNSB1S8EP DISPLAY DRIVER DISPLAY GRID DRIVER DAH1 Q8 C QUTPUTFILAMENTA OUTPUTFILAMENTB 59 49 00611 00610 55 051 VACDSPL 2R22CH a ak Se PH2 Gi 614 24022 19 0622 15 00020 15 00618 17 i 09617 18 096015 19 00615 20 00614 21 tl cag d 50 10UF DUE B C60 C81 Sur T T 5790A
52. SETACV SYNC RES 001 2 Set 5790A to the WIDEBAND 7V range Apply 3 2V at 1kHz from the 5700 then adjust the 5700A until the 5790A reads 3 2000 Press SET REF soft key on 5790 Readjust the 5700A until the HP 3458A reads 3 20000V Read the error on the 5790A display and record on the 1 kHz line in Table 3 16 Proceed to the 2 2V 700 220 mV and 70 mV ranges repeating steps 2 through 6 applying the voltages listed in Table 3 9 under 5790A INPUT for each range and adjusting the 5700A for the nominal value for each range 3 33 WIDEBAND 1 kHz GAIN VERIFICATION 22 mV RANGE 1 Connect the equipment as shown in Figure 3 20 using the attenuators specified in Table 3 9 DO NOT CONNECT the HP 34584 input to the Type N tee at this time Set the HP 3458Ato SETACV SYNC RES 001 2 Setthe 5790A to the WIDEBAND 22 mV range 3 Apply 3 2V at 1 kHz from the 5700A then adjust the 5700A until 5790A reads10 0000 mV 4 Connect the HP 34584 to the Type N tee Calculate the 5790A error using the following formula 57904 ERROR 3458A MEASURED VALUE 1 e 100 57908 READING 5 Record calculated error 1 kHz line Table 3 16 6 Disconnect HP 3458 input from tee Proceed to 7 mV 2 2 mV ranges repeating steps 2 through 6 applying the voltages and attenuation listed in Table 3 9
53. Voltage RUE 32 E sev eme oosr oe ws om wes _ Lorm o De ew o _ one oro _ om on o or oro _ some oe oro sev ose o os respe _ oem os respe Le o o o _ ome o _ De om ame on fos ese rese _ sv one sm sev oos Der mm oov sem eov oov sem sov wow Loor E sov mom oo Ee om ow ner oov m Loor vov oo sem sov oov Ce sem wow 3 61 5790 Table 3 16 Wideband Verification Test Record cont If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatness Erro
54. nesre m rw oam ons wo Se sues oor nesre mr ore wo sper ms m ozm ore nesre m ror ore nesre wr mr ore ms rw asev su ore or ore wo sper me rm sem om rm wwe os om wo sper GERE ome om wo sper me rm ozm om om esee wo sper me mr oss os wo sper me rm ons oe wo sper ons oa wo sper ur mr sem some one me sem mv ww ome for me sew rmv mw omm om m sew im omm om m sew ome om ms sew mom ome om ms sem vm wm me sem sm ome om Lus sev rmv wwe omm om ose me sev some omm om ur sev owe omm om ose 3 63 5790 Table 3 16 Wideband Verification Test Record cont If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatn
55. sm f arre 3 Esse meme C UE 74 EGIT EASE S EXE 8 8 y 2 FET PWR N CHL R05A TRANSISTOR SI N DMOS PWR 680967 FET TO 92 Q12 13 Q16 17 N JFET ROSR TRANSISTOR SI N JFET SEL TO 92 845458 Q23 24 o m T Boys sec c as ea List of Replacable Parts 6 Parts Lists 030 032 07 JFET SI N SST4416 30V 5MA 5000HMS SELECTED 806612 1 j Q10 RDS ON SOT 23 TAPE 031 033 035 NPN MMBT2369 SMR TRANSISTOR SI NPN 40V 300MW SOT 844584 PNP MMBTH81 SMR TRANSISTOR SI PNP 20V 300MW SOT 782938 R39 R44 RESISTOR RO5A RES CF 3K 596 0 25W 890 4 La T prem RESISTOR SMR RES CERM 910 5 125W 200PPM 1206 Tar R10 R27 RESISTOR METAL FILM 2 49K eae SESI 1 0 25W 100PPM RADIAL TAPE R13 RESISTOR SMR RES CERM 22 5 125W 200PPM 1206 RESISTOR METAL FILM 1 21K Fr 1 0 25W 100PPM RADIAL TAPE RESISTOR SMR RES CERM 750 5 125W 200PPM 1206 RESISTOR SMR RES CERM 2 49K 1 125W 100PPM 1206 L m Le R37 R110 R3 RESISTOR SMR RES CERM 12 5 125W 200PPM 1206 R40 RESISTOR SMR RES CERM 100K 5 125W 200PPM 1206 R46 RESISTOR SMR RES CERM 360 5 125W 200PPM 1206 R49 RESISTOR SMR RES CER
56. 1693 Figure 6 16 A16A1 DAC Filter 6 57 5790 6 58 Table 6 18 A17 Regulator Guard Crossing Part Ref Des Description t ELCHE 1 2 4 6 7 9 CAPACITOR ELECTROLYTIC ALUMINUM 10UF 799437 13 C11 12 C14 15 20 50V SOLV PROOF 2 5MM LS RADIAL TAPE C20 C23 C28 C3 C10 CAPACITOR CAP CER 0 05UF 20 100V Z5V 149161 2 C5 C24 C102 CAPACITOR RO2A CAP AL 22UF 20 35V SOLV PROOF 851766 EMEN C54 C56 C59 60 CAPACITOR FILM POLYESTER 0 1UF 10 50V 5MM 649913 13 C101 C104 107 LS RADIAL TAPE C109 110 C112 113 CAPACITOR ROSR CAP TA 10UF 20 10V mares 2 Fa mew CAPACITOR ROSR CAP CER 22PF 5 50V COG rus 2 CAPACITOR CAP TA 22UF 20 25V 1 17 20 21 DIODE 1N4007 A52R DIODE SI 1KV 1A DO 41 707075 24 26 27 CR36 DIODE SI 1N4448 75V 150MA 4NS RADIAL LEAD 659516 PREP DO 35 TAPE CR37 THYRISTOR SCR THYRISTOR SI SCR VBO 200V 8 0A 634147 H19 22 RIVET AL 089 DIA 344 L SEMI TUBULAR OVAL HEAD 838458 H45 48 SCREW SCREW PH P LOCK SS 6 32 500 320051 1 5 HEAT DISSIPATOR HEAT DIS PRESS 418384 2 ON 315ID 750OD TO 5 16 5700A 2708 RIVETED VOLTAGE REGULATOR AIR DUCT 802777 EN ED MP28 BAG MYLAR STATIC SHIELD OPEN TOP 0031 10 00 14 00 680967 31 MP35 36 EJECTOR EJECTOR PWB NYLON 494724 2 59 60 INSULATION PART INSUL TRANSISTOR 152207 2 MOUNT DAP TO 5 MP71 8840A 8019 PAD ADHESI
57. 19 20 21 22 23 24 Calibration and Verification 3 Service Calibration Press DO STEP softkey and enter the 1 kHz reference value just measured for the APPLIED VALUE Set the 5700A to 3 2 V at 10 Hz and adjust the 5700A to the total error value at 10 Hz for the 2 2 V range as recorded in Table 3 8 Press the ENTER key and the system will calibrate the range at 10 Hz and step to the 100 Hz calibration point as before Set the 5700A to 100 Hz and adjust for errors Press LAST ENTRY then press ENTER as before The system will calibrate the 100 Hz point and step to the 10 kHz point Proceed through the range at each calibration point as before by applying the proper frequency and error values All remaining ranges are done in a similar manner by installing the proper attenuators establishing the 1 kHz reference and adjusting for errors at each frequency When all the ranges are calibrated store the calibration constants to complete the calibration procedure The rear panel CALIBRATION STORE switch must be in the ENABLE position to store the calibration constants Return the switch to the NORMAL position after the constants are stored 3 22 Service Calibration Service Calibration is a more complete calibration that should be done only after repair or replacement of an analog module Service calibration is the procedure done at the factory when the 5790A is built However Fluke uses an autom
58. 20 proceed as follows Note After you replace the battery the setting of the time and date the elapsed time counter read by the remote query and set by ETIME will need to be reprogrammed Query the ETIME setting before you proceed 1 Make sure the power is off and the power cord disconnected 2 Follow the access procedures to remove the digital side cover 3 Remove the CPU Assembly A20 4 Desolder and remove battery 5 Solder a replacement battery in place refer to the parts list for replacement information if necessary 4 21 Using Remote Commands Reserved for Servicing 4 22 This information documents remote commands not described in the 5790A Operator Manual Chapters 5 and 6 The commands described here are useful for servicing the instrument Using the FATALITY and FATALCLR Commands The FATALITY query recovers fault codes that were logged when a fatal problem occurred These faults are logged into a separate fault queue Once the faults are read from the queue you can clear the queue by sending the FATALCLR command The syntax for these remote commands are as follows FATALITY Returns the list of the fatal faults logged since the list was last cleared by the FATALCLR command Sequential command Parameter None Response String The list of faults one per line in the following format Example 8 30 91 6 33 49 Fault 4301 Rom Checksum 8 30 91 6 34 05 Fault 4301 Ro
59. 4 7K NORMAL CHASSIS ENABLE CALIBRATION SWITCHES PERIODIC SERVICE INTERNAL RS232 CONNECTOR FOR S W TEST 410 SN75189AJ 5790 1021 2 of 2 Figure 7 19 A21 Rear Panel I O PCA cont 7 58 Schematic Diagrams 7 22 N ADAPTER PWB ree RIS 2 O A INPUT 1 mu BRN y DRAIN 3 1 SHUNT ORN 5790A 4402 INPUT 2 4 DRAIN BLK TOROID e A24 GROUNDSTRAP PWB 2 FULL TURNS DRAIN 1 BLU DRAIN 2 INPUT 2 LO GROUND 2 NOTES UNLESS OTHERWSE SPECIFIED FRONT INPUT CABLE PWB 2 ALL RESISTORS ARE IN OHMS 7 ALL CAPACITOR VALUES ARE MICROFARADS 5790 4406 WIDEBAND lt 1 WIDEBAND CABLE TOROID 1 FULL TURN 5790A 2016 INPUT BLOCK 5790 1022 Figure 7 20 62 Block Assembly 7 59 5790 NOTES UNLESS OTHERWISE SPECIFIED 1 ALL RESISTOR VALUES ARE IN OHMS 53 2 U2 8PIN PLASTIC DIP PACKAGE TO BE MOUNTED FLUSH TO SUBSTRATE R21 HEATER RESISTOR IS DETERMINED BY EXTERNAL JUMPERS SUBSTRATE THICKNESS 25 MIL USE LALSS LBADS 513622 USE LOW THERMAL MATERIAL ON LEADS P10 PINS 10 11 R6 TTS 300 c3 MATCHED TO R25 14 5790A 1H01 Figure 7 21 A16HR6 DC Amp Hybrid on the A16 DAC PCA 7 60 S
60. Proceed to the next range and establish the 1 kHz reference at 3 2 V as in step 10 Press the REF soft key on the 5790A and proceed through each frequency in the table Reset the 5700A to 3 2 V after each frequency is measured The error values are set relative to the nominal 3 2 V level Verify all other ranges in the same way 3 67 5790 3 68 static awareness A Message From Fluke Corporation Some semiconductors and custom IC s can be damaged by electrostatic discharge during handling This notice explains how you can o minimize the chances of destroying such devices gt 1 Knowing that there is problem 2 Learning the guidelines for handling them 3 Using the procedures packaging and bench techniques that are recommended The following practices should be followed to minimize damage to 5 6 static sensitive devices LL 3 DISCHARGE PERSONAL STATIC BEFORE HANDLING DEVICES USE A HIGH RESIS 1 MINIMIZE HANDLING TANCE GROUNDING WRIST STRAP 2 KEEP PARTS IN ORIGINAL CONTAINERS UNTIL READY FOR USE 4 HANDLE S S DEVICES BY THE BODY 5 USE STATIC SHIELDING CONTAINERS FOR 8 WHEN REMOVING PLUG IN ASSEMBLIES HANDLING AND TRANSPORT HANDLE ONLY BY NON CONDUCTIVE EDGES AND NEVER TOUCH OPEN EDGE CONNECTOR EXCEPT AT STATIC FREE WORK STATION PLACING SHORTING STRIPS ON EDGE CONNECTOR HELPS PROTECT INSTALLED S S DEVICES 6 DO NOT SLIDE
61. RLH COM AS CR24 IN MICROFARADS 7804 7617 T 144007 i 144007 5790 1017 Figure 7 15 A17 Regulator Guard Crossing cont 7 42 Schematic Diagrams US2 MICROCONTROLLER us 02522 HCT244 12 ae 014 HD8303YP P20 TIN P21 TOUT1 gt 22 501 ccce L 1x7 8 SPARE _ 10 14 P24 TX 28 700 2 T P26 TOUT3 PULSES 18 K lt 2 P52 MR 5 P63 HALT PBAVIS pees 32 ngs os E 25d 255 PS CLRCNTR_ DS75451N Ai LATGHs SEN 8 oT SPARES XREF TL7708 5 158 204 aw x ALE switcH css Tas z IN r o 18 8 51 082 18 cas ANN E RESET 1TO0UF O TUF 213 5 1 AAA Ths IN I 0 21 READ POP AIG 1 19 IN 753 VVV 5 IN 1 0 33 CLIE 154 sy i ARE 3 3 URDZW 1 9 952 uses B4E THS270256 20NL AG uu 3 c H62629 10 ABI ats X 413 812 ABI 24 i ASIE 21 4 25 1N4448 ABI S 28 28 SCLK 10 84 ABTA 27 aia URS 27 R 1_ 14 11 ROMSELs 20 4 E RAMSELs 26
62. Ref Des Description Number Qty Notes CR1 6 LED GREEN SUBMINIATURE W1 5700A 4401 CABLE MOTHER BD TO DISPLAY 802694 1 6 5790 Biens S 5 5790 1601 Figure 6 3 1 Keyboard 6 18 List of Replacable Parts 6 Parts Lists Table 6 5 A2 Front Panel PCA CAPACITOR SMR CAP TA 47UF 20 10V 746990 E C2 C4 C9 20 CAPACITOR SMR CAP CER 0 1UF 747287 C28 C30 C35 10 25V X7R 1206 37 39 46 64 21 27 CAPACITOR SMR CAP TA 10UF 20 25V 6032 927814 17 C29 C31 C36 C38 C47 50 C66 eme PFL 51 54 2094 100V X7R 1206 TAPE LENNNLLLILIS HHH CAPACITOR CAP POLYPR 0 33UF 5 50V HERMETIC Ed 59 61 62 CAP POLYES 0 68UF 20 100V 912506 CAPACITOR R05A CAP POLYES 0 68UF CAPACITOR ROSA CAP POLYES 0 68UF 20 100V 100V 912506 I LEAKAGE 2 LEAD 92 TUBE DISPLAY VACFLORZ ROW22CHAR DISPLAY VAC FLOR 2 ROW 22 CHAR 996 eee PWB 40 PINLATCHING BUMPER RUBBER BLACK 50 BUMPER RUBBER BLACK 50 SQ 12 12 THK ADHESIVE 99e 0 zo 0031 18 00 18 00 per 29 SMR TRANSISTOR SIPNP 50V 350MW SOT 23 per H OH SMR TRANSISTOR 50 350MW SOT 23 R1 R3 R5 6 RESISTOR SMR RES CERM 4 7K
63. The 70 mV output of Z2 is connected by FET 015 to the input of the RMS sensor amplifier Q6 and U5 When the 80 Hz chopped reference WB is needed in the signal path Q15 opens the input signal path and Q16 switches in WB Input Signal Path for the Lower Four Ranges The 70 mV 22 mV 7 mV and 2 2 mV ranges follow a different path to sensor buffer amplifier U5 as shown in the block diagram Relays K1 and K4 are deactivated and relays and K10 are activated A 50 load is provided by Z3 and the signal passes through FET Q13 to an amplifier attenuator network composed of 25 dB amplifier Q3 and U3 10 to 30 dB attenuator Z4 with relays K5 and K6 17 dB amplifier U2 and then through FET switch Q17 to RMS sensor amplifier Q6 and US When the 80 Hz chopped reference WB CHOP is needed in the signal path Q13 opens the input signal path and Q14 switches in WB CHOP FET switches for the upper four ranges Q15 and Q16 are always turned off in the lower four ranges 2 47 5790 Service Manual The lower four ranges are Input signal paths are configured as follows e 70mV range The signal is connected to 25 dB amplifier U3 through FET Q13 and amplified to 1 2 V Resistor R29 50 and load 74 50 drop the signal 6 dB to 600 mV at K5 Relays K5 and are reset which passes the signal through both the 10 dB and 20 dB sections of resistor network Z4 to give a signal level at the input of the 17 dB ampli
64. 0 gt 19 o 81 3 BYPASS CAPS 23 PROTECTION DETECT amp 100 35 25C 25A RLHCOM 5790A 1010 4 of 4 Figure 7 8 A10 Transfer PCA cont 7 28 Schematic Diagrams 7 Q7 N CHANNEL eta Soa N CHANNEL R15 Wr 1M 5790A 1691 5790A 1091 Figure 7 9 A10A1 Precision Amplifier PCA 7 29 5790 R6 P1 5 INPUT R1 R2 WA 200MA 200MA 200MA ort 330K 330K 330K CRS R30 EC 92 s MENSEM SI CS 5 aig 0050 Q 180MA OUTPUT Ee VNO550 R21 T RT1 200 CR2 0300 330 330K PVI5100 UNLESS OTHERWISE SPECIFIED ALL RESISTORS ARE IN OHMS ALL CAPACITOR VALUES ARE IN MICROFARADS 5790A 1692 5790A 1092 Figure 7 10 A10A2 High Voltage Protection PCA 7 30 Schematic Diagrams 7 TS c EFO 9814 63 g 99 n 04 c3 CI iE LI 26 ice 00 8 m 07 VR3 9 VR4 qh gr a 5790 1695 NOTES UNLESS OTHERWISE SPECIFIED i ALL RESISTORS ARE IN OHMS ALL CAPACITOR VALUES ARE IN MICROFARADS 57904 1095 Figure 7 11 A10A3 High Gain Precision Amplifie
65. 1 Yr Flatness Specification Measured Flatness Error 90 90 Days Absolute Error Spec Measured Absolute 700 sare oum oe ene oer foo _ so roomy foo Noses _ roomy oro roomy enix _ roomy oro _ roomy oro _ mon we o _ Lm mon ors Ls roomy oon ors mon ose o _ roomy oss o _ Fm roomy o _ roomy ome _ om _ o _ m mon oo m son ow m mon ow BH 5790A Range Test Voltage BE mem zov 0010 3 59 5790 Table 3 16 Wideband Verification Test Record cont If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatness Error 90 90 Days Absolute Error Spec Measured Absolute Error 220 100 mv
66. 100 kHz 300 kHz 1 5 10 10 300 kHz 500 kHz 3 0 40 40 500 kHz 1 MHz 4 5 100 100 ppm of Reading 10 Hz 20 Hz 18 5 5 20 Hz 40Hz 18 5 5 40 Hz 20 kHz 18 5 5 20 kHz 50 kHz 18 5 5 210 70 mV 50 kHz 100 kHz 24 8 8 100 kHz 300 kHz 24 10 10 300 kHz 500 kHz 48 30 30 500 kHz 1 MHz 150 75 75 10 Hz 20 Hz 12 1 5 3 0 20 Hz 40 Hz 8 1 5 3 0 40 Hz 20 kHz 8 1 5 3 0 gt 10 220 20 kHz 50 kHz 8 2 0 3 0 50 kHz 100 kHz 18 5 0 8 0 100 kHz 300 kHz 24 10 0 10 0 300 kHz 500 kHz 36 20 0 20 0 500 kHz 1 MHz 120 50 0 50 0 Introduction and Specifications Specifications Secondary Performance and Operating Characteristics cont 24 Hour AC Temperature Coefficient Stability 1 Voltage Range Frequency Range Slow Filter 10 to 40 EN ae 2 of Reading 10 Hz 20 Hz 8 1 5 3 0 20 Hz 40 Hz 6 1 5 3 0 40 Hz 20 kHz 6 1 5 3 0 gt 10 700 20 50 2 6 2 0 3 0 50 kHz 100 kHz 12 5 0 8 0 100 kHz 300 kHz 18 10 0 10 0 300 kHz 500 kHz 36 20 0 20 0 500 kHz 1 MHz 96 50 0 50 0 10 Hz 20 Hz 8 1 5 3 0 20 Hz 40 Hz 5 1 5 3 0 40 Hz 20 kHz 5 1 5 3 0 22V 20 kHz 50 kHz 5 2 0 3 0 gt 10 50 kHz 100 kHz 10 5 0 8 0 100 kHz 300 kHz 18 10 0 10 0 300 kHz 500 kHz 30 20 0 20 0 500 kHz 1 MHz 90 50 0 50 0 10 Hz 20 Hz 8 1 5 3 0 20 Hz 40 Hz 5 1 5 3 0 40 Hz 20 kHz 5 1 5 3 0 20 kHz 50 kHz 5
67. 15 and 15 respectively Inputs fused with 1 6 A slow blow fuses F1 and F2 2 51 Unregulated LH Supplies Line 5 LH is the return path for the 5 LHR and 5 LHR supplies These supplies use a full wave center tapped configuration and consist of four diodes CR1 CR2 CR4 CR5 configured as a bridge rectifier The capacitors C2 and C3 filter 5 LHR and C5 filters 5 LHR Capacitor C1 reduces the level of generated transients 2 52 Unregulated 17 SR Supplies The 17 SR supplies use a full wave center tapped rectifier consisting of four diodes CR8 CR10 CR12 CR13 configured as a bridge rectifier Capacitors C13 and C14 filter the 17 SR supply while C15 and C16 filter the 17 SR supply 2 53 Triac Circuit The circuit protects the 5790A if it is inadvertently plugged into an excessively high line voltage For example it protects the 5790A if it is plugged into a 230 V line when the rear panel line voltage select switches are set for 115 V operation This circuit contains triac CR19 zener diodes VR20 VR21 resistor R1 and capacitor C23 The zener diodes set a trip voltage of 82 V If the AC voltage across the main transformer secondary for the 17 V supply exceeds 82 V the triac fires shorting out the winding which causes the main transformer primary fuse to blow 2 54 Supplies Line is the return path for unregulated 5 FR1R raw supply and the regulated
68. 20 10V 658971 9 19 21 CAPACITOR ROSR CAP TA 4 7UF 20 25V 807644 22 22 29 32 34 C36 C40 C1 84 85 C20 C24 CAPACITOR CAP VAR 0 35 3 5PF 250V AIR 603456 IE 23 114 9 C11 CAPACITOR FILM POLYESTER Q 1UF 1096 50V 5MM 649913 4 LS RADIAL TAPE C25 CAPACITOR RO2R CAP CER 82PF 2 100V COG 512350 C26 C28 C31 C35 CAPACITOR ROSR CAP CER 0 10UF 20 50V X7R 853650 35 C37 C41 C43 C46 C48 C53 C59 C61 C63 C66 67 C73 75 C77 78 C82 83 C87 C90 92 C95 96 C98 99 C101 103 C105 106 C27 C44 45 C47 CAPACITOR ROSR CAP CER 1000 20 50 7 697458 C50 C57 c30 CAPACITOR RO5A CAP CER 18PF 2 100V COG 830638 CAPACITOR ROSA CAP POLYES 0 47UF 10 50V 697409 Fe CAPACITOR ROSA CAP POLYES 1UF 10 50V 733089 C49 CAPACITOR RO5R CAP CER 68PF 2 50V COG 715300 51 54 CAPACITOR RO5R CAP CER 1000PF 2 50V COG 807966 64 71 76 CAPACITOR 100 590 50 831495 86 88 89 94 C100 ar C104 CAPACITOR 22 296 50 nem 1 S OH CAPACITOR R05R CAP CER 0 22UF 80 20 50V Z5U 7336 1 CR1 R5 DIODE FDH400 DIODE SI 200V 500MA DO 35 876867 4 CR14 15 CR24 25 CR30 31 CR9 12 CR20 21 DIODE 1N4448 A52R DIODE SI 75V 150MA DO 35 203323 17 CR26 29 2 4 6 8 6 27 5790
69. 25C 886960 1 U1 4 BIPOLAR 385 IC 2 5V 100 PPM T C BANDGAP REF 723478 4 4 U5 7 OPTOCOUPLER PVI5080 LED TO PHOTOVOLTAIC 128598 3 SOURCE OUTPUT 5V 8UA DIP8 4 BULK Notes 1 Static sensitive part 6 2 5 o Pi 2 5790 1692 61 978 S Figure 6 12 A10A2 High Voltage Protection Amplifier 6 45 5790 6 46 Table 6 14 A10A3 High Gain Precision Amplifier aw Part enen PME C1 C2 CAPACITOR SMR CAP CER 270PF 10 50V C0G 1206 837385 2 CAPACITOR SMR CAP TA 4 7UF 20 10V 3528 867262 C4 CAPACITOR FILM POLYESTER 0 47UF 10 50V 5MM 913736 1 PCM RADIAL BULK C7 11 CAPACITOR SMR CAP CER 0 22UF 80 20 50V Y5V 1206 740597 CAPACITOR R05R CAP CER 0 22UF 80 20 50V Z5U 733386 CR1 2 CR5 DIODE SI PN BAV99 70V 215MA 6NS DUAL SERIES SOT 23 TAPE 742320 CR3 CR6 DIODE 2MA 10 SEL TO 226AC 284927 CURRENT REGULATOR DIODE J511 5 3MA 21 3 1 50V 2 LEAD TO 92 TAPE OD BRASS SWAGE 062 PANEL THK Iar Lr 02 3 08 9 TRANSISTOR SI PNP MMBT3906 40V 200MA 250MHZ 225MW SOT 742684 4 j 23 TAPE NPN MMBT3904 SMR TRANSISTOR SI NPN 60V 350MW SOT 23 742676 23 TAPE ret mance RESISTOR SMR RES CERM 6 2K 5 125W 200PPM 1206 746016 1 IRR T rem sss RIR nene ss RESISTOR SMR RES CERM 18K 5 125W 2
70. 70 mV through POO MV Range tees esistere eene 3 49 3 29 Verifying Absolute AC Error for Region II 2 2 V through 1000 Range eerte e ree iau Pe Ee 3 52 3 30 Verifying Absolute AC Error for Region V 2 2 mV through Didi O ha eee 3 53 3 31 Verifying the Wideband AC Option sse 3 53 32 Wideband 1 kHz Gain VerificatioN 7V 2 2V 700 mV and 70 mV Ranges RR DERE 3 33 WIDEBAND 1 kHz GAIN VERIFICATION 22 mV RANGE 3 34 Wideband Gain Verification 10 Hz to 500 3 66 3 35 Wideband Flatness Verification eese 4 1 IntrodUctiOD soe 4 3 424 Cleaning the Air Filter T 4 3 43 General Cleaning iecore tre er erret 4 3 4 4 222020 etes tinet asas 4 4 4 5 Access 4 4 4 6 and Bottom 4 4 4 7 Digital Section COVGF ei tiet iere 4 5 4 8 Analog Section 4 4 4 9 Rear Panel Removal and Installation 4 4 4 10 Rear Panel Assembly Access
71. 700 100 2 220 300 2 70 V AC 500 kHz 70 V AC 1 MHz 22 V AC 100 kHz 22 V AC 1 MHz 7 V AC 100 kHz 7 V AC 1 MHz 2 2 V AC 1 MHz 700 mV AC 1 MHz 220 mV AC 1 MHz 70 mV AC 300 kHz 70 mV AC 1 MHz 22 mV AC 300 kHz 22 mV AC 1 MHz 7 mV AC 300 kHz 7 mV AC 1 MHz 2 2 mV AC 300 kHz 2 2 mV AC 1 MHz 2 mV RMS 1 MHz 600 V RMS 100 kHz 600 V RMS 100 kHz 60 V RMS 300 kHz 20 V RMS 500 kHz 20 V RMS 1 MHz 20 V RMS 100 kHz 20 V RMS 1 MHz 6 V RMS 100 kHz 6 V RMS 1 MHz 2 V RMS 1 MHz 600 mV RMS 1 MHz 200 mV RMS 1 MHz 60 mV RMS 300 kHz 60 mV RMS 1 MHz 20 mV RMS 300 kHz 20 mV RMS 1 MHz 6 mV RMS 300 kHz 6 mV RMS 1 MHz 2 mV RMS 300 kHz Tolerance Calibration Source PPM 70 2300 2300 Table 3 5 Calibration Steps in Periodic Calibration cont Purpose of Calibration Step Generates flatness calibration data for the 1000 V range Generates flatness calibration data for the 700 V range Generates flatness calibration data for the 220 V range Generates flatness calibration data for the 70 V range Generates flatness calibration data for the 22 V range Generates flatness calibration data for the 7 V range Generates flatness calibration data for the 2 2 V range Generates flatness calibration data for the 700 mV range Generates flatness calibration data for the 220 mV range Generates flatness calibration data
72. 740522 R8 R10 12 5 125W 200PPM 1206 R20 R28 30 R55 59 R61 R63 R65 R72 eee ee R40 41 R52 53 5 125W 200PPM 1206 R70 R73 75 5 125W 200PPM 1206 1 125W 100PPM 1206 a R51 R54 5 125W 200PPM 1206 5 125W 200PPM 1206 6 19 5790 6 20 60 862 864 866 596 125 2002 1206 CT CT 5 125W 200PPM 1206 5 125W 200PPM 1206 R47 48 RESISTOR SMR RES CERM 453 1 125W 100PPM 1206 R49 50 RESISTOR SMR RES CERM 1 5K 5 125W 200PPM 1206 5 125W 200PPM 1206 RESISTOR SMR RES CERM 91 5 125W 200PPM 1206 wm r RESISTOR CERMET 200 5 0 5W 200PPM 2010 TAPE AUDIO TRANSDUCER PIEZO SOUNDER 4KHZ 25V 22MM RND BULK SRAM PLCC 5700A 90720 PLCC44 90721 PLCC Mare 90722 PLCC D o EE COUNTER SOIC SPEED SOIC I EE RIPPLE CNTR SOIC p ew 90723 PLCC LATCHES SOIC w pee WIS TRG SOIC U13 TTL 7406 SMR IC TTL HEX INVERTER W OPEN 741249 1 COLL SOIC un 23 IC DISPLAY DRIVER HV518 5 0V 80V PLCC44 TAPE 741231 r a CMOS 5C060 SM IC CMOS PLD PROGRAMD 5700A 837369 90724 uno 10 CMOS 74HCT04 INVERTER SOIC 74 04 SMR IC CMOS HEX INVERTER SOIC 742585 eS 886700 VR5 ZENER UNCOMP MMBZ5231B 5 1V 5 20MA 225MW 837179 1 23 5700A 4401 CABLE MOTHER BD TO DISPLAY 802694 4 Static sensitive part List of
73. Appendix Calibration Constant Information The constants in these tables are arranged by group Eh group is stored as a block in nonvolatile memory The value given for eh constant in this list is the default assigned value before the instrument 15 first calibrated Defaults are reinstated if you perform format of the EEPROM ALL or CAL areas Note Refer to Chapter 2 of the 5790A Service Manual for calibration constant theory of operation Table C 1 Group ZC_BASIC Internally Calibrated DAC Sensor and A D Parameters mme pa Doxur Tann _________ so DS Dwumez oo msn oo intera C wane senor ove C 1 5790 Table 2 Group FREQ Frequency Counter Table C 3 Group DC_DAC Reference DAC Coarse Channel Gain 30170 Table C 4 Group WDC_SENSOR Wideband Sensor Linearization SENSOR C1 WB 3 162277660e 03 Wideband thermal sensor linearization Sensor c2 wb 00000 Wideband thermal sensor linearization Table C 5 Group AC LINEARITY Low Frequency Linearization Table C 6 Group FACTORY Ftory Service Calibrated Corrections INPUT2 LO 150 0E 6 INPUT2 vs INPUT1 flatness 2 2 V INPUT2 MID 350 0E 6 INPUT2 vs INPUT1 flatness 2 2 220 V INPUT2 HI 17 0 6 INPUT2 vs INPUT1 flatness gt 220 V Table C 7 Group DC 2 2 DC Constants 2 2 mV Range DI 2 2MV 5000 0 Basic gain Ref DAC to in
74. For the 2 2 V range and below relays K1 and K2 select the input The output of these relays route the input signal through the protection circuit A10A2 The protection circuit output is switched into the precision amplifiers by U1 the same way as the 220 V 22 V divider taps The protection circuit protects the precision amplifiers from destructive voltages The circuit behaves like a 1 series resistance during normal operation and quickly changes to an extremely high resistance when the voltage exceeds about 4 V SHUNT Input Signal Path The SHUNT input is compatible with the Fluke series of A40 current shunts These shunts when used with the adapter shipped with the 5790A allow you to measure relative current between 2 5 mA and 20 A with a full scale output voltage of 0 5 V RMS Relay 5 switches the SHUNT signal into the terminating 90 9 resistor R7 The signal is then applied to the precision amplifiers through U1 and U2 in much the same way as in the 1000 V and 700 V ranges Precision Amplifiers To maintain high input impedance at the 5790A INPUT terminals an amplifier buffers input signals before they are applied to the FTS which has an input impedance of 400 The input impedance specification of the 5790A varies from 50 to 10 depending on the input voltage range Amplifiers are also required in some ranges to boost the input signal to the appropriate level for the FTS The optimum operating range for the FTS is b
75. Introduction and Specifications 43 cm 17 0 in Fluke 5790 O 63 cm 24 8 gt Specifications 17 8 cm 7 0 in 6 35 cm 2 5 in FOR CABLE ACCESS REAR Figure 1 1 Dimensions elu001 eps 1 5790 Chapter 2 Theory of Operation Title Page Tint T T u aun re dents 5790A OVErVIEW Functional Block Diagram 015 0 Digital Section Analog Section 2 000 eere System Interconnect Detailed Circuit Description Digital Motherboard Assembly A4 Transformer Assembly A22 a Analog Motherboard Assembly A3 Rear Panel I O Assembly A21 sse Rear Panel Power Rear Panel Digital Control seen Clock Regeneration Circuit esses IEEE 488 GPIB Interface
76. MEAS in the 5790A using the keypad and press the ENTER key After you press ENTER the Control Display shows the progress of the internal process of the calibration step Note While a calibration step is in progress inaccurate values may appear on the Measurement Display This is normal When the 57904 is finished with the step the display will read accurately 1 When step has completed set 5700 to standby 8 Foran AC calibration point in the 2 mV through 20 mV group you use a bootstrapping technique This procedure assumes the you have calibrated the 60 mV points Each range is bootstrapped from the next higher range as shown in Figure 3 9 3 25 5790 Service Manual 3 26 60 70 RANGE 20 22 mV RANGE 9 NZ 7mV 22mv RANGE o6mv N elu033 eps Figure 3 9 Millivolt Range Bootstrapping Technique a Calibrate the 22 mV range as follows 1 2 3 4 5 6 Lock 5790 in 70 mV range The 792A may be left attached although it 1 not used Apply the requested voltage and frequency When the reading on the 5790A Measurement Display settles record the reading Press the DO Step softkey This automatically selects the 22 mV range Enter the value you recorded in step 2 and press the ENTER softkey When the step 15 completed set the 570
77. Medium Fast 100 counts Medium Slow Course Fast 1000 counts Medium Slow 1200 V rms 10 V peak 1 10 100 ppm 10 digits 100 ppm 2 digits 1 00 Hz to 119 99 Hz 0 1200 kHz to 1 1999 kHz 1 200 kHz to 11 999 kHz 12 00 kHz to 119 99 kHz 0 1200 MHz to 1 0000 MHz 1 000 MHz to 1 1999 MHz Wideband only 1 200 MHz to 11 999 MHz Wideband only 12 00 MHz to 30 0 Mhz Wideband only 2 seconds per reading 2 seconds decreasing linearly to 1 second at 200 Hz 1 second per reading range lock 1 sample 6 seconds 8 seconds 4 seconds 4 averaged samples 10 seconds 16 seconds 8 seconds 16 averaged samples 22 seconds 32 seconds 16 seconds 32 averaged samples 40 seconds 64 seconds 32 seconds 10 counts 100 counts 100 counts 1000 counts 1000 counts 10000 counts Specified for sinewave with THD less than 196 Specifications 1 5790 Service Manual Wideband Uncertainty Specifications Option 03 2 Flatness Flatness Absolute Uncertainty 0 to 50 Voltage Temperatur abd Resolution Reading Coericient uV ppm 90 Days 1 Year 2 Years 10 Hz 30 Hz 0 10 0 75 0 5 1 2 0 6 1 5 0 8 2 30 2 120 2 0 05 0 75 0 5 1 2 0 6 1 5 0 8 2 120 Hz 1 2 2 0 05 0 75 0 5 1 2 0 6 1 5 0 8 2 1 2 kHz 120 kHz 0 05 0 75 0 5 1 2 0 6 1 5 0 8 2 22 mv 120 500 2 0
78. NULL DAC 016 2 39 5790 Service Manual 2 40 2 92 2 93 2 94 Instrumentation Amplifier The instrumentation amplifier amplifies the difference between the output of the Null DAC and the output of the circuit on the Transfer Assembly The output of the instrumentation amplifier is fed directly into the A D Amplifier IC U24 The result of this system 15 greatly improved resolution from the A D IC The instrumentation amplifier is switched between a unity gain and an X10 configuration Components U14 U15 are used as 4 to 1 multiplexers to select the input signal to the noninverting and inverting inputs to the instrumentation amp The noninverting input can be connected to lines RCL DAC SNS HI R COM or NULL DAC The inverting input can be connected to DIV OUT DAC SNS HI R COM or NULL DAC Components U19 and U20 buffer the inputs Components U21 Z2 and Z3 convert the differential input signal to a single ended output available at TP14 Equivalent to TP10 minus 9 The single ended output 15 fed to the A D IC through R27 If this voltage is too large for the A D to read a signal six times smaller is available through R29 and R30 Maximum resolution 15 obtained using U22 R24 and R25 as an X10 amplifier Capacitor C14 filters the high frequency noise and VR2 and VR3 clamp the output to less than the A D ICs power rails Components U2 R45 through 47 and C42 through 44 form a three pole Bessel active filt
79. SEQ SEQ SEQ SEQ SER SER SER SER SER SER SYS TST TST TST TST TST TST TST TST TST TST TST TST GOG G GG GG Inguard CPU command error Timed out waiting for inguard reply Sequence name too long Element array full Name array full Already defining a sequence Not defining a sequence Command failed Bad virtual channel 4 framing d input queue overflow d overrun Parity UART failed self test Bad interrupt vect h 02x A20 main CPU ROM checksum A20 main CPU RAM A20 main CPU Real time clock A01 Keyboard keyboard A02 Display Output display A02 Display Control display 21 Rear panel IEEE488 A2 Rear panel Rear panel DUART A20 main CPU Guard crossing DUART A20 main CPU Watchdog timer A20 main CPU Watchdog A2 Display Refresh To format set switches to ENABLE and SERVICE Can t store CAL STORE switch NORMAL Cant set string CAL STORE switch NORMAL Domain error 5 Singularity 80 Overflow 5 Underflow 5 Error s S 2300 65535 WD ERR Watchdog timed out tid d Unknown error Maintenance Error Codes 4 5790 Chapter 5 Troubleshooting Title 5 1 u u 5 2 CPU A20 Power Up Tests 5 3 A17 Guard Crossing Processor Power Up 5 4 System startup a u 5 5 Diagnostic Tesf ____ aasassaa
80. Service Calibration Full or Range Calibration Automating Calibration and Verification How Calibration Memory is Organized How to Use the Calibration Menus The Cal Menu Zero Cal Softkey See Cal Dates Softkey Cal Reports Softkey Update Cal Dates Menu Periodic Calibration Calibrating the Main Input Characterizing the DC Source DC Calibration AC Calibration Calibrating the Wideband AC Optio Characterizing the AC Source Calibrating Wideband Input Gain at 1 kHz Calibrating Wideband Input Service Calibration Xfer Offset Adjustment Wideband Amplifier Rolloff Adjustment MenfiCatlon uet Verifying the Main Input INPUT 1 Verifying AC DC Difference for 220 mV through 1000 V Range iii Regions and Contents continued N gt gt gt gt gt E LE LS gt LU gt P LE LS L O b Lp LER Lp po po N gt 5790 3 28 Verifying Absolute AC Error for Region IV
81. The AC source maximum uncertainty can be met by measuring down scale on the next higher range of the 5790A as described in the procedure Table 3 13a Main Input Frequency Verification STEP 5790A VOLTAGE TEST 1 YEAR MEASURED NO RANGE FREQUENCY FREQUENCY FREQUENCY SPEC ERROR r z z ne o 1 Apply the test voltage into the 5790A INPUT 1 or INPUT 2 and PM6666 counter The Measured Error is the deviation of the 5790A from the counter 3 27 Verifying AC DC Difference for Regions and 220 mV through 1000 V Range You calculate the AC DC difference error by comparing the AC DC difference of the source as measured by the 5790A and the 792A do this use the instrument setup and technique as described under AC Calibration Proceed as follows to verify AC DC difference in regions I and III 1 Use the setup in Figure 3 8 and the procedure under Calibration 2 Foreach point take AC and DC measurements and enter them in copies of worksheet Figure 3 15 or Figure 3 16 Use Figure 3 15 and characterized DC settings for the 700 mV 220 mV and 70 mV ranges as follows Set the 5700 to nominal than use the knob to adjust for the error display you recorded in Table 3 3 The procedure to obtain those settings is described under Characterizing the DC Source at the beginning of the calibration instructions in this chapter Use Figure 3 16 and nominal DC outputs for ranges other than those list
82. sav wv mew sv uv oo o 3 57 5790 Table 3 16 Wideband Verification Test Record cont 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 2 2V 1 0V 61 2 2V 1 0V 62 2 2V 1 0V 63 700mV 320mV 64 700 mV 320 mV 65 700mV 320mV 700 mV 320 mV 67 700 mV 320 mV 700 mV 320 mV 700 mV 320 mV 70 700 mV 320 mV 71 700 mV 320 mV 72 700 mV 320 mV N 3 700mV 320 mV N 4 700 mV 320 mV 75 700 mV 320 mV N keee Ree RR EREREEREREEREREER m 3 58 700 kHz 1 MHz 1 2 2 2 MHz 3 MHz 4 MHz 6 MHz 8 MHz 9 MHz 10 MHz 12 MHz 15 MHz 17 MHz 20 MHz 23 MHz 26 MHz 28 MHz 30 MHz 10 Hz 20 Hz 50 Hz 100 Hz 200 Hz 1 2 2 2 10 2 20 2 50 2 100 2 200 2 500 2 If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatness Error 90 Days Absolute Error Spec Measured Absolute Error No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec No Spec Calibration and Verification 3 Verification Table 3 16 Wideband Verification Test Record cont If Using Methods Other Than Specified Max Uncert
83. time If the microprocessor attempts to write to the RAM location that U4 is reading as it refreshes the DMD U3 uses BUSYD to hold off DTACK to the microprocessor This prevents the written data from being lost The other busy signal generated when U4 attempts to read from a location being written to by the microprocessor is ignored Losing display data for one refresh cycle is insignificant Measurement Display Circuitry Measurement Display circuitry consists of a custom 2 row 22 character vacuum fluorescent display under the control of PLD US The circuit contains high voltage grid driver U15 high voltage anode driver U14 a filament switching circuit anda 1 K X 8 1 KB dual port RAM U2 The custom display is divided into 24 grids The 22 characters are made up of fourteen seven segment digits and eight 14 segment characters See the schematic diagram for more information IC US is an EP900 PLD programmed to provide the timing and control signals for the Measurement Display circuitry Display data written by the microprocessor into the Measurement Display s dual port U2 is read by 05 and sent serially to the high voltage anode driver Both the anode and the grid drivers are serial TTL level input 32 bit parallel high voltage output devices Only 31 anode driver outputs and 24 grid driver outputs are used the remaining high voltage outputs are left unconnected IC U5 also controls grid timing and display refresh 2 2
84. voltage at Q6 pin 6 until the sensor DC voltage 15 approximately zero 2 48 2 112 2 113 Theory of Operation 2 Analog Section Detailed Circuit Description Range Comparator Comparator U11 and U13 and associated parts form a circuit that indicates when the RMS sensor circuit is being driven beyond normal limits Each of the 4 Schottky diodes CR16 through CR19 is biased by current sources Q7 and Q8 to 6 mA each When amplifier U5 is forced by the large input signals to drive more than 6 mA output the diode CR16 and CR19 stop conducting The 12 mA from Q7 flows through CR17 and split between the sensor input at U15 pin 10 and R126 The sensor receives 7 6 mA which gives 3 V across the 400 input of RMS sensor 015 pin 10 The 3 V is a safe level for the sensor When amplifier U5 is forced to drive more than 6 mA output diodes CR18 and stop conducting and the 12 mA from 8 is split between the resistors and sensor input The sensor voltage is thereby clamped at 3 V When the diodes stop conducting in either direction the voltage at U5 pin 6 output jumps to the saturated level of 5 V When the output of amplifier U5 reaches 32 5 V comparator U11 pin 4 or pin 9 drops low pin 4 for 42 5 V and pin 9 for 2 5 V and pulls the voltage of capacitor C63 down to the trip level of 1 5 V at the input of U13 pin 3 The output of U13 at pin 1 drops low and indicates the need to change to the next highest range At this sign
85. 04 40 0 3 60 0 4 80 0 5 100 120 Hz 1 2 kHz 0 04 40 0 3 60 0 4 80 0 5 100 1 2 kHz 120 kHz 0 04 40 0 3 60 0 4 80 0 5 100 220 mV 120 kHz 500 kHz 0 04 40 0 3 60 0 4 80 0 5 100 1 0 500 kHz 1 2 MHz 0 05 40 1 2 MHz 2 MHz 0 05 75 2 MHz 10 MHz 0 1 100 10 MHz 20 MHz 0 15 100 20 MHz 30 MHz 0 35 200 Introduction and Specifications Wideband Characteristics Maximum Non Destructive Input 200 V rms Guard Isolation 2 0 5 Input Impedance WAZ 500 0 5 96 SOMH Z 500 5 Wideband VSWR with 50 Source 500 0 5 96 SOMEZ usu us 50 Q 5 Shunt Input Characteristics The shunt input was designed to allow ac dc current transfers using the Fluke A40 Series current shunts 5790A 7001 A40 A40A Current Shunt Adapter and Cable required Shunt Model Current Range AAO alahala Ad 2 5 mA A40A 5 20 Input Resistance 91 O t 1 96 1 Specifications Wideband Uncertainty Specifications Option 03 cont Flatness F Flatness 2 Absolute Uncertainty 0 to 50 Voltage Frequency Range Temperature ee Resolution Range Reading Coefficient ppm C 90 Days 1 Year 2 Years 10 Hz 30 Hz 0 10 40 0 3 20
86. 07 1 75 0 5 1 2 0 6 1 5 0 8 2 0 1 uV 500 kHz 1 2 MHz 0 07 1 75 1 2 MHz 2 MHz 0 07 1 100 2 MHz 10 MHz 0 17 1 200 10 MHz 20 MHz 0 30 1 200 20 MHz 30 MHz 0 70 2 400 10 2 30 2 0 10 0 75 0 4 5 0 5 7 0 7 8 30 2 120 2 0 05 0 75 0 4 5 0 547 0 7 8 120 Hz 1 2 kHz 0 05 0 75 0 4 5 0 5 7 0 7 8 1 2 120 2 0 05 0 75 0 4 5 0 5 7 0 7 8 7 mV 120 kHz 500 kHz 0 07 1 75 0 4 5 0 5 7 0 7 8 0 1 uV 500 kHz 1 2 MHz 0 07 1 75 1 2 MHz 2 MHz 0 07 1 100 2 2 10 2 0 1151 200 10 MHz 20 MHz 0 17 1 200 20 MHz 30 MHz 0 37 1 300 10 Hz 30 Hz 0 10 75 0 4 10 0 5 13 0 7 16 30 Hz 120 Hz 0 05 75 0 4 10 0 5 13 0 7 16 120 Hz 1 2 kHz 0 05 75 0 4 10 0 5 13 0 7 16 1 2 kHz 120 kHz 0 05 75 0 4 10 0 5 13 0 7 16 22 mV 120 kHz 500 kHz 0 07 75 0 4 10 0 5 13 0 7 16 0 1 uV 500 kHz 1 2 MHz 0 07 75 1 2 MHz 2 MHz 0 07 75 2 MHz 10 MHz 0 1 100 10 MHz 20 MHz 0 17 100 20 MHz 30 MHz 0 37 200 10 Hz 30 Hz 0 10 40 0 4 20 0 5 30 0 6 40 30 Hz 120 Hz 0 05 40 0 4 20 0 5 30 0 6 40 120 Hz 1 2 kHz 0 05 40 0 4 20 0 5 30 0 6 40 1 2 120 2 0 05 40 0 4 20 0 5 30 0 6 40 70 120 2 500 2 0 05 40 0 4 20 0 5 30 0 6 40 1 0 nV 500 kHz 1 2 MHz 0 05 40 1 2 MHz 2 MHz 0 05 75 2 MHz 10 MHz 0 1 100 10 MHz 20 MHz 0 15 100 20 MHz 30 MHz 0 35 200 10 Hz 30 Hz 0 10 40 0 3 60 0 4 80 0 5 100 30 Hz 120 Hz 0
87. 1 5 210 1 5 20 Hz 40 Hz 73 75 1 5 76 1 5 78 1 5 40 Hz 20 kHz 27 31 1 5 33 1 5 38 1 5 T 20 kHz 50 kHz 47 50 2 0 51 2 0 56 2 0 50 kHz 100 kHz 7942 5 79 2 5 84 2 5 100 kHz 300 2 160 4 0 180 4 0 210 4 0 300 kHz 500 kHz 300 6 0 300 8 0 340 8 0 500 kHz 1 MHz 900 6 0 960 8 0 1200 8 0 1 For 9 5 to 10 Hz the specifications is 1000 ppm of reading 1 5 uV 1 6 Introduction and Specifications 1 Specifications Absolute Uncertainty Specifications cont 5 of Calibration Temperature Absolute Uncertainty Measurement Mode Pea Frequency Range of Reading 2 Years 90 Days 1 2 Years 10 Hz 20 Hz 200 200 200 200 20 Hz 40 Hz 63 65 66 69 40 Hz 20 kHz 18 22 24 29 20 kHz 50 kHz 43 45 46 52 50 kHz 100 kHz 70 71 76 100 kHz 300 kHz 150 160 200 300 kHz 500 kHz 250 260 310 500 kHz 1 MHz 840 900 1200 10 Hz 20 Hz 200 200 200 200 20 Hz 40 Hz 63 66 67 70 40 Hz 20 kHz 18 22 24 29 yu 20 kHz 50 kHz 44 46 48 53 50 kHz 100 kHz 80 81 88 100 kHz 300 kHz 180 190 220 300 kHz 500 kHz 380 400 470 500 kHz 1 MHz 1100 1200 1500 10 Hz 20 Hz 200 200 200 200 20 Hz 40 Hz 63 66 67 70 40 Hz 20 kHz 21 25 27 31 7 20 kHz 50 kHz 44 46 48 53 50 kHz 100 kHz 80 81 85 100 kHz 300 kHz 180 190 220 300 kHz 500 kHz 380 400 470 500 kHz 1 MHz 1100 1200 1500 10 Hz 20 Hz 200 200 2
88. 1 kHz 2 V RMS 20 kHz 2 V RMS 300 kHz 2 V RMS 1 MHz 600 mV RMS 10 Hz 600 mV RMS 1 kHz 600 mV RMS 20 kHz 600 mV RMS 300 kHz 600 mV RMS 1 MHz 200 mV RMS 10 Hz 200 mV RMS 1 kHz 200 mV RMS 20 kHz 200 mV RMS 300 kHz 200 mV RMS 1 MHz Tolerance of Calibration Source PPM Table 3 10 Calibration Steps in Service Calibration cont Purpose of Calibration Step Generates flatness calibration data for the 70 V range Generates flatness calibration data for the 22 V range Generates flatness calibration data for the 7 V range Generates flatness calibration data for the 2 2 V range Generates flatness calibration data for the 700 mV range Generates flatness calibration data for the 220 mV range 70 mV AC 10 Hz 70 mV AC 1 kHz 70 mV AC 20 kHz 70 mV AC 300 kHz 70 mV AC 1 MHz 22 mV AC 10 Hz 22 mV AC 1 kHz 22 mV AC 20 kHz 22 mV AC 300 kHz 22 mV AC 500 kHz 22 mV AC 1 MHz 7 mV 10 Hz 7 mV AC 1 kHz 7 mV AC 20 kHz 7 mV AC 300 kHz 7 mV AC 500 kHz 7 mV AC 800 kHz 7 mV AC 1 MHz 2 2 mV AC 10 Hz 2 2 mV AC 1 kHz 2 2 mV AC 20 kHz 2 2 mV AC 300 kHz 2 2 mV AC 500 kHz 2 2 mV AC 800 kHz 2 2 mV AC 1 MHz Voltage to Apply 60 mV RMS 10 Hz 60 mV RMS 1 kHz 60 mV RMS 20 kHz 60 mV RMS 300 kHz 60 mV RMS 1 MHz 20 mV RMS 10 Hz 20 mV RMS 1 kHz 20 mV RMS 20 kHz 20 mV RMS 300 kHz 20 mV RMS 500 kHz 20 mV RMS 1 MHz 6 mV RMS 10 Hz 6 mV RMS 1 kHz 6 mV RMS 20 kHz
89. 10 50V CAPACITOR ROSR CAP CER 4 7PF 0 25PF 50V COG 721837 1 C7 13 14 CAPACITOR ROSR CAP CER 470PF 5 50V COG 830430 5 C16 C18 C8 CAPACITOR CERAMIC 10PF 0 25PF 50V COG 5MM 713875 LS RADIAL TAPE C10 11 CAPACITOR ROSR CAP TA 10UF 20 35V 816512 7 C120 124 C12 CAPACITOR FILM POLYESTER 0 22UF 5 50V 5MM 747519 1 LS RADIAL TAPE C15 C17 CAPACITOR ROSA CAP POLYES 0 47UF 10 50V 697409 2 CAPACITOR ROSR CAP CER 1 8PF 0 25PF 100V COK 816660 1 CAPACITOR ROSR CAP CER 82PF 2 50V COG 714857 1 22 23 R05R CAP CER 1000PF 20 50V X7R 697458 2 CAPACITOR RO2R CAP CER 2 7PF 0 25PF 100V COJ 816231 1 CAPACITOR ROSR CAP CER 33PF 596 50 714543 1 CAPACITOR RO5R CAP CER 270PF 5 50V COG 658898 1 110 111 CAPACITOR ROSR CAP TA 4 7UF 20 25V 807644 4 114 115 152 CAPACITOR CERAMIC 0 22UF 80 20 50V Z5U RADIAL TAPE 649939 1 3 4 CR1 3 DIODE SI PN JPAD5 35V 10MA 5PA REVERSE LEAKAGE 2 LEAD 723817 92 5 24 DIODE SI 1N4448 75V 150MA ANS RADIAL LEAD PREP DO 659516 26 4 CR26 27 35 TAPE CR30 33 CR28 29 DIODE SI PN FDH300 125V 200MA RADIAL LEAD PREP DO 844647 35 TAPE N 6 37 5790 SURGE PROTECTOR 420V 15 AXIAL BULK L1 INDUCTOR 12UH 5 368MADC 1 76OHM SHIELDED AXIAL BUL K INDUCTOR 8 2UH 5 535MADC 828MOHM SHIELDED AXIAL BU LK 5700A 2064 OSCILLATOR THERMAL COVER MP2 3 EJECTOR EJECTOR PWB NYLON BAG
90. 10 25 0 2 IN 1 0 23 377 22 PROMOCS 4 IN i 0 21 ADCLKCS 29 NYNCS IN 19 PROM OSs IN 18 DTACK U18 U16 22 SHT2 93373 5HT8 U13 20 SHT U17 U18 22 5uT2 23 A23 170 17 L PROM2CS 18 RAMZOS BRPDTK IN 1 IN i70 15 RAM TCS BFPDTK 15 RAMOCSs U23 U24 22 SHT3 U40 U41 22 SHT3 U21 U022 22 SHT3 U19 U20 22 SHTS DRTDTK IN 05 PAL IMAGE MISCCS i 92 13 5 1 622 10 25 I O 1 23 22 GEDRTCS 170 26 19 FRNIPNLEN x 1 0 C17 RRPNLEN 170 16 RPSEL BERR XN CK PALLIMAGE U31 35 SHT5 21I XDUARTCS 0322 35 SHTS U10 13 SHT1 U28 1 19 SHT4 1 P220 C23 SHT4 170 _15 BUSERRT 84d0000H892N MAIN PROCESSOR READ WRITE LOGIC 1 3 2 99 n 6 5 99 DOGCLR2 DOGCLR BYPASS CAPACITORS x Sw zzzzzzz DOGINTH 1 145
91. 1W AXIAL TAPE R38 R48 R65 R73 RESISTOR A52R RES CF 51 5 0 25W 414540 R83 R96 R99 R105 R143 R43 RESISTOR 5 50 0 05 0 125 15 500264 R44 RESISTOR A52R RES MF 154 1 0 125W 100PPM 447987 Ea 1 3 5 1 1 R45 R87 RESISTOR METAL FILM 1 27K 245753 2 1 0 5W 100PPM AXIAL TAPE 2 4 1 R46 R54 R60 RESISTOR AS52R RES CF 5 1 5 0 25W 441287 R67 R115 R120 R49 R106 R126 RESISTOR A52R RES MF 499 1 0 125W 50PPM 289256 R141 R53 R94 RESISTOR A52R RES MF 30 9 1 0 125W 100PPM 321315 R58 R110 RESISTOR A52R RES CF 3K 5 0 25W 441527 2 RESISTOR A52R RES MF 54 9K 1 0 125W 100PPM 271353 R69 70 R92 R114 RESISTOR METAL FILM 909 312629 5 R116 19 0 1251 100 R71 R77 R84 R97 RESISTOR A52R RES MF 82 5 2W 100PPM 876875 R121 R125 72 8111 RESISTOR 52 5 2 32 1 0 125 100 312652 2 R74 R109 RESISTOR A52R RES MF 392 1 0 125W 100PPM 260299 R75 RESISTOR A52R RES CF 330K 5 0 25W 376640 R76 RESISTOR A52R RES MF 1 5K 1 0 125W 100PPM 313098 R78 RESISTOR A52R RES CF 3 6K 5 0 25W 442343 1 mas R79 R93 RESISTOR METAL FILM 237 328005 2 4 0 125W 100PPM AXIAL TAPE R81 RESISTOR A52R RES MF 332 1 0 125W 100PPM 192898 R82 RESISTOR A52R RES CF 82K 5 0 25W R85 R88 RESISTOR A52R RES CF 68K 5 0 25W 376632 R86 RESISTOR A52R RES MF 26 7K 1 0 125W 100PPM 245779 R89 R91 RESISTOR A52R RES MF 6 49K 1 0 125W 100PPM 294900
92. 2 INIdi voz 1843 I3S3HH vez 31IHMdi vez 6091 vor X043 vic 41941 YZS FPCLK FPWRITE BRESET FPDTK HINIIIVAiSd FPDTK 12V 1N4002 12 10d3 57904 1004 12V FAN CR4 1N4002 C4 12V Figure 7 4 4 Digital Motherboard PCA cont 7 16 Schematic Diagrams 7 ried v GL chia IBS3 VR3IE iN CR T 1 89 CR CR26 r 5790 1606 Figure 7 5 Wideband Option 03 7 17 5790 COAX SMBM PWB ANG CR25 CHR24 l FDH40 CR31 CRI 5LH 13 17 17 S 18 gt gt 400 FDH480 CRIS CR14 FDHAOO FDHAOO CR3 CRS FDH486 Fr DHAOD I 44 V V LOW A97 IN INPUT HI TUS 57988 4097 PROTECTION OUT GND VS 15 16 19 LE INPUT PROTECTION VR4 1 14448 6D 29 NNV 1 K FETS 5123 023 13 CR18 CR26 INP PROT U27 4 SHT 3 CR27 1N4448 144448 Y iN R34 W
93. 210 1 3 210 1 3 20 50 2 400 2 0 400 2 0 410 2 0 50 kHz 100 kHz 600 2 5 600 2 5 610 2 5 100 kHz 300 kHz 1200 4 0 1200 4 0 1200 4 0 300 kHz 500 kHz 1300 6 0 1300 8 0 1400 8 0 500 kHz 1 MHz 2000 6 0 2300 8 0 3600 8 0 10 Hz 20 Hz 290 1 3 290 1 3 290 1 3 20 Hz 40 Hz 180 1 3 190 1 3 190 1 3 40 Hz 20 kHz 110 1 3 110 1 3 110 1 3 dorm 20 kHz 50 kHz 210 2 0 210 2 0 210 2 0 50 kHz 100 kHz 310 2 5 310 2 5 310 2 5 100 kHz 300 kHz 810 4 0 810 4 0 820 4 0 300 kHz 500 kHz 860 6 0 890 8 0 1000 8 0 500 kHz 1 MHz 1400 6 0 1700 8 0 2600 8 0 10 Hz 20 Hz 240 1 5 240 1 5 240 1 5 20 Hz 40 Hz 120 1 5 120 1 5 130 1 5 40 Hz 20 kHz 64 1 5 65 1 5 69 1 5 20 kHz 50 kHz 120 2 0 130 2 0 130 2 0 50 kHz 100 kHz 260 2 5 260 2 5 260 2 5 100 kHz 300 2 510 4 0 510 4 0 530 4 0 300 kHz 500 kHz 660 6 0 670 8 0 680 8 0 500 kHz 1 MHz 1100 6 0 1100 8 0 1300 8 0 10 Hz 20 Hz 210 210 1 5 210 1 5 210 1 5 20 Hz 40 Hz 82 84 1 5 85 1 5 87 1 5 40 Hz 20 kHz 34 37 1 5 38 1 5 43 1 5 20 kHz 50 kHz 67 69 2 0 69 2 0 73 2 0 50 kHz 100 kHz 160 2 5 160 4 2 5 160 2 5 100 kHz 300 2 240 4 0 250 4 0 280 4 0 300 kHz 500 kHz 360 6 0 380 8 0 400 8 0 500 kHz 1 MHz 940 6 0 1000 8 0 1200 8 0 10 Hz 20 Hz 210 210 1 5 210
94. 3 Introduction 3 1 Introduction This chapter gives procedures for calibrating and verifying a normally operating 5790A In case of malfunction refer to Chapter 5 This chapter defines the 5790A calibration methods then presents step by step procedures for calibrating the main input You can apply calibration voltages to either INPUT 1 or INPUT 2 Calibration is valid for both inputs after calibration is complete Following main input calibration is the procedure to calibrate the WIDEBAND input only if the Option 5790A 03 Wideband AC module is installed Verification is a procedure you can use to determine calibration status in or out of tolerance on recall Procedures for verifying the main input and Wideband option are presented separately 3 2 Calibration Cycle Calibration is required as often as specified by your selected calibration cycle You choose a 90 DAY 1 YEAR or 2 YEAR calibration cycle in a setup menu as described in Chapter 4 or using remote commands as described in Chapters 5 and 6 The calibration procedure is the same for all calibration intervals Your calibration cycle selection determines which set of specifications from Chapter 1 is valid It is also used for Cal Shift Reports and for display when you press the SPEC key 3 3 Periodic and Service Calibration Periodic calibration is what you perform at the end of each calibration cycle and is all that is required to keep a normally functioning 5790A operat
95. 3 18 Worksheet for DC Error 2 2 V through 1000 V Ranges 3 54 Calibration and Verification 3 Verification Table 3 14 Worksheet for Wideband 22 mV 7 mV and 2 2 mV 1 kHz Gain Measured by Measured by Range Input Voltage 5790A at INPUT 1 ENT at aw ew LL few ECL ew jw Table 3 15 Wideband Flatness Verification Worksheet 10 dB Error 20 dB Error 20 dB Error 20 dB Error Error PPM 1 kHz Ref Frequency A55 Corr me P P P j Eur ass CS P j Be j j jP me j p j mes j j P 12 12 42 j j jP ___ j Jj j pow P P j P j pe P P P ___ pee P jP aes jJ k Bes j PPF ___ Bem P P P j ___ gu qn P P P ___ ewe yj p p p k 3 55 5790 Table 3 15 Wideband Flatness Verification Worksheet cont 5790A Error 5700A Error 55 Corr If Using Methods 90 Days Absolute Measured Absolute Other Than Specified Max Uncert 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V 3 2 V
96. 3 of Figure 2 1 in the block diagram After M1 and M2 are taken the CPU computes value of the unknown AC voltage at the input called Vac using the following formula Vac Vdc M2 M1 If Vac and Vdc closely agree the results are displayed on the front panel and the measurement is complete If the difference between Vac and Vdc is too large the CPU readjusts the DAC based on the above formula and begins another measurement cycle Calibration constants to correct for FTS and amplifier frequency response variations are stored in memory and applied to measurements before they are displayed In order to apply the correct constants a frequency counter measures the frequency of the incoming signal Digital Section Overview The unguarded Digital Section contains the CPU assembly A20 the Digital Power Supply assembly A19 Front Panel assembly A2 Keyboard assembly A1 and the Rear Panel I O assembly A21 Figure 2 2 is a block diagram of the digital section of the 5790 Power digital assemblies cooling fans is supplied Digital Power Supply assembly The CPU central processing unit assembly is a single board computer based on the 68000 microprocessor It controls the local and remote interfaces as well as serial communications over a fiber optic link to the guard crossing the portion of the Regulator Guard Crossing assembly A17 The guard crossing controls the guarded analog circui
97. 350MW TO 92 N JFET ROSR TRANSISTORSINJFETSELTO 92 JFET ROSR TRANSISTOR SI N JFET SEL TO 92 sme 4 rssicon s r R2 RESISTOR A52R RES CF 36 5 0 25W ume 1 sm 2 R4 RESISTOR A52R RES MF 10K 1 0 125W 100PPM 9e a RESISTOR A52R RES MF 1K 1 0 125W 100PPM 168229 a HH R7 RESISTOR AS52R RES CF 62K 5 0 25W 1 RESISTOR A52R RES MF 2K 1 0 125W 100PPM 226 1 eooo R11 RESISTOR A52R RES CF 330 5 0 25W 1 Rr RESISTOR 52 200 596 0 25 1 RESISTOR A52R RES MF 1 43K RESISTOR AS2R RES MF 1 43K 1 0 125W 25PPM 0 125W 25PPM ER EE LT1016C IC COMPARATOR HI 822197 SPEED PRECISION 74F161A IC FTTL SYNC DIV BY 16 BINARY CNTR 74F161A IC FTTL SYNC DIV BY 16 BINARY 876883 BA GE SWITCH ADG201HS 15V 75 875328 OHMS SPST QUAD DIP16 TUBES List of Replacable Parts 6 Parts Lists BIPOLAR 3096 IC ARRAY 5 TRANS 5 ISO 2 3 418954 U5 BIPOLAR LT1013C IC OP AMP DUAL PRECISION 8 PIN 783696 1 j DIP BIPOLAR AD633 IC BPLR ANALOG MULTIPLIER 845151 s ZENER 52 7 6 4 5 20 4 381988 RESISTOR NETWORK CERMET ISOLATED 8 4 714345 RES 1K 2 0 2W 100PPM SIP8 BULK RESISTOR RES CERM SIP 8 PIN 4 RES 10K 2 513309 6 33 CRIS 489 REP ST Service Manua
98. 4HR9 DC Amplifier Hybrid AHR6 The DAC uses a pulse width modulated scheme to vary its output The main DAC circuits that work together for a stable and linear DC voltage are 13V temperature controlled reference hybrid 4HR9 e Duty cycle control circuitry A five pole active filter A16A1 assembly e An output stage Among the support circuits are Asense cancellation circuit e Linearity control circuits e Negative offset circuit these blocks are shown in Figure 2 9 the block diagram of the DAC assembly The two inputs of the five pole filter are two precision square waves with different fixed amplitudes and independently variable duty cycles controlled by software The filter s first input square wave 15 called the first channel It is switched between the reference voltage 13 V and 0 V 2 41 5790 Service Manual 2 42 The filter s second input square wave is called the second channel It 15 switched between approximately 0 78 mV and 0 V Its amplitude 15 derived resistively dividing the 13 V reference This second channel is used for extra resolution The filter reJects all AC components of the waveforms above 30 Hz Since the frequency of the square waves is 190 Hz the output of the filter is a DC voltage which is the sum of the average voltages of the two waveforms The Output Stage which consists of the DC amplifier hybrid and the output buffer isolates the filter output from the DAC output a
99. 500 KHz 100 mV 700 kHz Spec 100 mV 1 MHz No Spec 100 mV 1 2 MHz Spec 100 mV 2 MHz No Spec 100 mV 3 MHz No Spec 100 mV 4 MHz Spec 100 mV 6 MHz Spec 100 mV 8 MHz Spec 100 mV 9 MHz Spec 100 mV 10 MHz Spec 12 2 Spec 15 MHz Spec 100 mV 17 MHz Spec 100 mV 20 MHz Spec 100 mV 23 MHz No Spec 100 mV 26 MHz Spec 100 mV 28 MHz i No Spec 100 mV 30 MHz Spec 046 046 7 220 220 220 220 1 220 2 220 220 4 220 220 220 7 220 100 mV 220 mV 100 mV 220 mV 220 mV 1 220 mV 2 220 mV 220 mV 4 220 mV 106 109 110 113 116 119 120 123 2 70 mV 126 70 mV 32 27 70 mV 32 mV BEER REB eae ERT EISELE ERE 2 70 mV 32 129 70 mV 32 70 mV 32 1 70 mV 32 2 70 mV 32 70 mV 32 4 70 mV 32 50 2 0 010 100 2 0 010 200 2 0 021 70 mV 32 mV lt k 0101010 wl wo 70 mV 32 3 60 Calibration and Verification 3 Verification Table 3 16 Wideband Verification Test Record cont If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatness Error 90 90 Days Absolute Error Spec Measured Absolute Error 5790 Range
100. 56 30 FRI 5 LHR 5 4c 4 5 LH COM 30 FR2 3c 30 5 LH CT 3c 2 5 FR2 2 24 15 5 5 LH 26 15 FR2 COM 16 FR2 COM 18315 5 5 LH ACI ic A D AMP o jw le jo la gt jo 5 32 5 2 52 8 31A 17 310 17 5 30A 17 5 306 30A x17 5 29 44 5 29 29 44 S 28A 44 5 286 28A _ t44 S 27A 8 27 27 8 RLH Y 26 28 26 l5 LH RLH COM 250 25 RLH COM 256 25A RLH COM LH COM 24 24 LH 24C 24 LH 5 RLH 230 23A 5 RLH 236 5 LH 22 224 5 LH 22 15 S 21C 21A 15 S 216 15 5 206 204 15 5 200 190 19 196 186 3 18 386 FROM ADC FROM ADC 176 174 XMIO 176 18A Dt 00 16t 15A D3 D2 150 15A D3 14 05 D4 146 14 05 Bo 0 13407 06 136 18A 97 124 WRe _ 12 __ 11A At 110 1 10A A2 ioc 10A POP sc RD WR BA INT CS14 7 7 CS12 510 CS8 4 4A 56 CS4e _ 2 052 CS0 471 HFBR2522
101. 5790A For each frequency in Table 3 8 set the 5700 frequency and perform steps 8 9 and 10 Apply any corrections for the response of the A55 TVC by first adjusting the 5700A output to bring the 8506 DMM offset reading to 0 3 counts and then pressing the NEW REF key 5700 and then further adjusting 5700A to give the same error and sign as recorded on the A55 calibration sheet when was calibrated Also record 455 correction Table 3 8 Record the error showing 5790 Control Display including polarity in Table 3 8 Return to 3 2 V at 1 kHz after each frequency calibrated to verify that the 8506A Is still reading 0 Rezero the 8506A if necessary by pressing the OFFSET STORE and OFFSET keys again The 5790A display should read 0 20 ppm If it does not press the CLR REF WBND softkey followed by SET softkey to rezero Set 5700 to STANDBY Remove the DMM A55 and the TEE and connect the 5700A wideband cable to the attenuator input as shown in Figure 3 11 13 14 15 3 20 Periodic Calibration Calibration and Verification 3 NO CABLES 5700A CALIBRATOR 5790A ATTEN ATTEN WIDEBAND 20 dB 10 dB WIDEBAND OUTPUT U NPON elu036 eps Figure 3 11 Wideband Calibration Source Characterization Part 2 Set the 5700A to 3 2 V at 1 kHz and then press the SET REF softkey
102. 6 E 5 2 JINGOW StSdlN 2 ZLS LLSdIN 2 2 VLG ELGdW 6 veS 2SH 9 91 91 015 705 9 229 15 ZvH 2 559 1544 1 Final Assembly Cont Figure 6 6 9 9406 911 206 9 2 LOSH v8v V 02 LYH S8FH wonog dol v Service Manual 5790A 2 ONITQNVH HONOY OL 1237805 YO GNIG 4040 LON ONITGNVH 1 12345 5381 038 SLYvd 0319341 1 SNIVINOO 188355 SIHL lt 031312345 3SIMH3HIO SS31N0 6 310 1 Final Assembly Cont Figure 6 6 10 6 Parts Lists List of Replacable Parts 930 p SLL 20629 9 91 S1H 015 09 LZ dIN 80rd 2 ASSY SISSVH2 62 82dN Z 80rd 30 18 4 0131 8 HOLIMS yg OL 338191 WILI gt 9 ZVV OvvH 62 9L SLH 2 20 015 0 lt 98 83 10 9 1 11910 7 Q8 90 V 1 Final Assembly Cont
103. 6 mV RMS 300 kHz 6 mV RMS 500 kHz 6 mV RMS 800 kHz 6 mV RMS 1 MHz 2 mV RMS 10 Hz 2 mV RMS 1 kHz 2 mV RMS 20 kHz 2 mV RMS 300 kHz 2 mV RMS 500 kHz 2 mV RMS 800 kHz 2 mV RMS 1 MHz Tolerance of Calibration Source PPM Calibration and Verification 3 Service Calibration Table 3 10 Calibration Steps in Service Calibration cont Purpose of Calibration Step Generates flatness calibration data for the 60 mV range Generates flatness calibration data for the 22 mV range Generates flatness calibration data for the 7 mV range Generates flatness calibration data for the 2 2 mV range 1 These uncertainties can be achieved using the bootstrap techniques described in the AC calibration procedure 3 23 Xfer Offset Adjustment If you repaired or replaced the Transfer assembly adjust the millivolt range amplifier offset for zero as follows 1 Turn off the power and unplug the 5790A 2 Remove eight flat head machine screws from the top cover and remove the top cover 3 Locate the access hole for potentiometer R27 on the guard cover as shown in Figure 3 14 3 39 5790 Service Manual 3 40 Set the CALIBRATION MODE switch to SERVICE Set the CALIBRATION STORE switch to ENABLE Turn on the 5790A power and allow it to warmup for 30 minutes Press UTIL MENUS key followed by the Cal softkey Press the Service Cal and Xfer Offset Adjus
104. ADCCOM M M Q TO CO M 5 1 5 FRIR 30 1 HEATER CONTROL 62 w HEATER CONTROL 50C 5700A 4HR9 5700A 4H06 NN VR3 16 COM 1 HEATER RESISTOR V uM ARE M RESISTOR ELEMENT 27 OHM 48 OHM 19 T 5 FRIR NOTES UNLESS OTHERWISE SPECIFIED 1 ALL RESISTORS ARE IN OHMS ALL CAPACITOR VALUES ARE IN MICROFARADS 5790A 1016 1 of 3 Figure 7 13 A16 DAC cont 7 87 5790 OUTPUT STAGE 30 FR1 30 1 C140 111 chia a 5 3MA 22 is 13 30 FR2 FRAI COML mesm 2 30FR1 I COM 5700 4 GB C24 REFERENCE HYBRID 1 d AJ 2 C 25K HR TP2 REF 43 121052 5790A 4HR9 COM R12 300 MEA COM 2 49 DAC OUT HI 300 i 2 49K 144448 95 104 CH Z COM 17 CH1 176 DAC OUT LO 1 COM 5 E COM LO MECCA RCOM 18 16 13 41 ee 5700A 4HR9 FR4 COM ces c27 A93 16 1 AVAN 44 LE 44 0 22 15 kee 1000PF 912 42086 FRi COM COM R29 30 1 COM 8 COM 26 DAC 5 5 L 1 25 40K 40K 27 i i I CR4 28
105. Calibration Artift Standard A stable object that produces or embodies a physical quantity for use as a reference standard An artift standard may have an assigned treable value when used for calibration purposes Fluke 732A DC Voltage Reference Standard and the Fluke 742A Series Standard Resistors are examples Also see transfer standard AC DC Absolute Uncertainty Includes all known error sources contributing to the uncertainty of an AC DC difference correction This includes NIST National Institute of Standards and Technology uncertainties transfer uncertainty from a primary standard to working standard and internal error contributions both random and temperature related A 1 5790 AC DC Transfer The process of comparing an AC voltage to a known DC voltage thereby transferring the low uncertainty of the DC voltage to the AC voltage The 792A can be used to perform two different types of AC DC transfers l An AC measurement 2 An AC DC difference measurement In an measurement the transfer standard is used to determine absolute RMS voltage level In an AC DC difference measurement the transfer standard is a reference that tests the and DC response of another transfer standard The goal of an measurement is to determine the error of the source or voltmeter under test The goal of an AC DC difference measurement is a value called the AC DC difference which is positive when more voltage tha
106. D 100 Zero Failed Error Code 3004 A15 A D 1 Zero Failed Error Code 3004 A15 A D 10 Zero Failed elu058 eps These errors indicate a possible fault on the A15 A D Amplifier assembly Referencing to the RCOM test point check for 0 V from the inputs of instrumentation amplifier to the inputs of U24 Test Step ADNULLDAC A D Null DAC This tests the interface and the output of the NULL DAC The test proceeds as follows 1 Connect NULLDAC to positive input and negative inputs of instrumentation amplifier Program NULLDAC to output 0 0 Measure with x1 A D range 2 Connect NULLDAC to positive input of instrumentation amplifier minus input to RCOM Program NULLDAC to output 0 0 Measure with x1 A D range 5 7 5790 Service Manual 5 8 Connect NULLDAC to positive input of instrumentation amplifier minus input to RCOM Program NULLDAC to output 1 0 Measure with x1 A D range Connect NULLDAC to negative input of Instrumentation amplifier positive input to RCOM Program NULLDAC to output 1 0 Measure with x1 A D range Connect NULLDAC to negative input of Instrumentation amplifier positive input to RCOM Program NULLDAC to output 2 0 Measure with x1 A D range Possible errors include Error 15 Null DAC 1 0 Failed Error 15 Null DAC 2 0 Failed Error A15 A D Null DAC 0 0 Failed Error A15 A D Null DAC 1 0 Failed Error A15 A D DAC NULLDAC Failed elu059 eps These errors ind
107. Display indications for each in Table 3 2 17 Set the 752A MODE switch to 10 V 18 Repeat steps 10 through 14 for 5700A outputs of 6 2 2 and 6 V DC entering the Error Display indications for each in Table 3 2 19 Disconnect the 720A and 5440B from the 752A Make the connections shown in Figure 3 4 5440B 5700A 0 0 7 00 752 845 A OY 8 L te tee te LI elu019 eps Figure 3 4 DC Source Characterization Setup Part 3 Note If the 845A is not grounded through the power cord a connection must be made to the 5440B ground as shown 20 Set the 5700A to 6 V OPERATE Edit the 5700A output until the Error Display matches that recorded in Table 3 2 for a 6 V output Set the 5440B to 6 V OPERATE Set the 845A range to 10 mV Set 845A to OPR Reduce the 845A range switch setting until the largest on scale reading is obtained Adjust 5790 21 22 23 24 25 26 27 28 the 5440B output for a null Repeat this procedure until you obtain a null of 1 uV Set the 845A OPR ZERO to ZERO and set the 5700A to STANDBY Record the 5440B voltage indication in Table 3 3 after 5440B CHARACTERIZED 6 V OUTPUT Set the 5440B to STANDBY Set the 5700A to 2 V OPERATE Set the 5440B to 2 V OPERATE Edit the 5700A output until the Error Display matches that recorded in Table 3
108. Divider error the most likely problem is that the cable from the divider the motherboard is not connected If the A10 Divider tests fail check the input switching on the A10 Transfer assembly 5 18 Test Steps X2 2V through X2 2MV Tests each range to the point where the chopper is injected This test proceeds as follows 1 Configure instrument as per normal setup for range but with open input 2 Setthe DAC so that the input of the instrumentation amplifier should be 1 0 This 15 done by multiplying the desired A D input by IA to reflect to input terminals and then multiply by DI to determine the DAC setting This implies that the input of the sensor should also be 1 0 3 Measure sensor output with x1 A D range Chopper is in HIGH state DC output Output of sensor is feed via RCL to A D for measuring Possible errors include Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer Transfer 1000 V Range Failed 2 2 mV Range Failed 2 2 V Range Failed 22 mV Range Failed 220 mV Range Failed 220 V Range Failed 22 V Range Failed 22 V HF Range Failed 7 mV Range Failed 70 mV Range Failed 700 mV Range Failed 700 V Range Failed 70 V Range Failed 7 Range Failed 7 HF Range Failed elu066 eps These errors indicate that a fault probably exists on A10 Transfer assembly Trace from point where chopper is input XF CHOP HI through amplifiers
109. Figure 3 15 Worksheet for AC DC Error 70 mV through 700 mV Ranges 3 50 NOMINAL Calibration and Verification 3 Verification FREQUENCY 792A CORRECTION PPM DC DC AVERAGE AC AC DC ERROR DC AVERAGE 1 0 I DCI 2 AC DC ERROR PPM 5790 5790 5790 10 792 elu044 eps Figure 3 16 Worksheet for AC DC Error All Other Ranges 3 51 5790 Service Manual 3 52 VOLTAGE NOMINAL FREQUENCY 5700A ERROR DISPLAY FROM TABLE 3 3 POSITIVE 5700A ERROR DISPLAY FROM TABLE 3 3 NEGATIVE 792A CORRECTION PPM DC DC AVERAGE AC AC ERROR DC AVERAGE 2 AC ERROR PPM 792 _ 792 CORR 792 10 NOMINAL NOMINAL elu045 eps Figure 3 17 Worksheet for Absolute AC Error 70 mV through 700 mV Ranges 3 29 Verifying Absolute AC Error for Region II 2 2 V through 1000 V Range Because of the loading of 792A in its 700 mV to 1000 V ranges the DC voltage at the reference point of the calibration center of the tee is not the same as the DC voltage at the output terminals of the source unless sense terminals are provided for the source to the tee If sense terminals are provided for DC the absolute AC error may be determined as for region II however the sense connections shou
110. Figure 6 6 11 5790 Service Manual 6 12 MP101 102 MP401 MP425 MP101 102 DETAIL I MP402 MP424 LN 4 OS see DETAIL CHASSIS ASSY s 9 Figure 6 1 Final Assembly Cont H503 506 5790a 115 5 OF 6 6 Parts Lists List of Replacable Parts 9400 911 206 9 t 917 2 22 ami A09 dol 1 1 1 8 dol 8 L CLH 9 LOSH 96t 6VH eLV 18VH Figure 6 1 Final Assembly Cont 6 13 5790 Table 6 3 A62 Input Block Assembly um eee 222028 CAPACITOR RO5R CAP CER 0 01UF 557587 1 10 100V X7R 12 2 DIODE 1N4002 A52R DIODE SI 100V 1A DO 41 698555 Emm H36 rr LOW THERMAL 8 32 850334 CERERI m6 1 16 5700A 8058 5700A 8058 WASHER LOW THERMAL 8 LOW THERMAL 8 859939 le 17 21 25 CABLE ACCESSORY CABLE 172080 H33 H38 39 ACCESS TIE 4 00L 10W 75 DIA SCREW 5 20 312 WASHER 494641 HEAD PHILLIPS STEEL ZINC CHROMATE HI LO THD FORM H23 24 TERMINAL TERM RING 6 26 832667 22AWG CRIMP GOLD H26 27 STANDOFF ROUND 6 32 375 250 877019 2 OD BRASS TIN SWAGE 094 PANEL H28 29 SCREW 6 32 312 TRUSS PHILLIPS STAINLESS 335174 Lu DENTS PASSIVATED STUD STUD BROACH PH BRNZ 8 32 312 STUD BROACH PH BRNZ 8 32 312 7 1
111. For inputs between 700 and 22 mV a different high gain signal path is employed This path is switched by Q7 and Q8 For inputs in this range the DISABLE signal is held high turning on Q7 and turning off Q8 allowing the AMP IN signal to be connected to U6 For voltages outside the 700 to 22 mV the DISABLE bit is driven negative opening Q7 and closing Q8 shorting the input of U6 to ground A gain of 100 or 40 dB is required to meet the nominal FTS input voltage for input voltages between 7 mV and 22 mV This is achieved by cascading U6 gain of 10 and A10A3 gain of 10 with U12 and K7 providing the necessary connections to FTS 05 The 2 mV and 7 mV ranges need an additional 20 dB and 10 dB of gain This gain 15 provided by switching the output of U6 into the input of amplifier U11 U11 15 configured with a gain of 10 20 dB and is switched into A10A3 by U12 for the 2 mV range For the 7 mV range the output of U11 15 attenuated by 10 dB by R10 and R36 and switched into A10A3 by 012 Thermal Sensor Circuit The FTS circuit converts the AC or DC signal at its input into a DC voltage equal to the RMS value of the input The FTS consists of two identical islands suspended in air each containing a heater resistor and an NPN transistor Each island provides close thermal coupling between the resistor and transistor Between islands there is high thermal isolation As shown in the schematic these two transistors are connected as
112. GRD key is on you must refresh the guard status after the instrument changes from the 220V range to any higher range To refresh push the EX GRD key two times once to turn the indicator off and once to turn the indicator on If using the remote interface send the commands EXTGUARD OFF and followed by EXTGUARD ON 7 Connect the equipment as shown in Figure 3 3 5440B 5700A 150 mr OO OO O 845 752 720 1 elu018 eps Figure 3 3 DC Source Characterization Setup Part 2 Note If the 845A is not grounded through the power cord a connection must be made to the 5440B ground as shown 8 10 11 Set the 752A to OPERATE MODE to 1000 V Set the 720A dials to 1 0000000 Set the 845 to the 10 mV range Set the 5700A to 1000 V OPERATE Set the 845A to OPR Reduce the 845A range switch setting until the largest on scale reading is obtained Adjust the 57004 for a null Repeat this procedure until you obtain a null of 1 uV Set the 845A OPR ZERO to ZERO and set the 5700A to STANDBY Record the 5700A Error Display indication in Table 3 2 under the column 57004 ERROR DISPLAY INDICATION TO OBTAIN CHARACTERIZED NOMINAL OUTPUT opposite 1000 V Set the 720A dials to 0 6000000 Set the 5700 to 600 V
113. JP20 NOTE 5V PLANE UNDER THE CRYSTAL 5V TRACE SURROUNDS THE CRYSTAL AND LOAD CAPACITOR TRACES ON AN INNER LAYER TO REDUCE BOARD CAPACITANCE 1 5790 1020 5 of 5 Figure 7 18 A20 CPU PCA cont 7 55 5790 CAUTION SUBJECT TO DAMAGE BY STATIC ELECTRICITY 57904 1621 Figure 7 19 A21 Rear Panel 7 56 Schematic Diagrams 7 1 ALL RESISTORS 5 5 ALL CAPACITOR VALUES ARE IN MICROFARADS 12V Designator 12V GND RXDA TXDA SERIAL CLOCK RXDB TXDB TO DIGITAL MOTHERBOARD PALC22V10 35PC U2 18 U5 32 SHT2 U3 11 SHT2 41214 245 TO SHT2 QOOOOOOOU0 U2 5 U5 8 SHT2 02 2 SHT2 gt TO SHT2 5790A 1021 1 of 2 Figure 7 19 A21 Rear Panel I O PCA cont 7 57 5790 U IEEE 488 CONNECTOR IEEE INTERFACE T TO 91 SHT1 UB SHT2 220 95 14 5 2 9121 REWRL s us 15 SHT1 _____ u8 20 SHT1 IEEE INT DUART INT REDRTINT TP7 SERIAL CLOCK RS232C CONNECTOR A 68 681 L a 5 RXDA RXDB 2 0 6 SHT2 18 5 Ut SHTI 2 0 4 0 5 21 LT 24 0 2 4 7 1 po 11 25 TO 4121 SHTI RPRZWRe IPs H 255 M SN75180Ad le UB8 14 SHT1 QUARTOS 08 7 DUARTBTERI IP3 2 5v is 19 E
114. KJS 1N4448 10K l 29 80 80K S E SE pL SHUNT LINEARITY R CONTROL ovy FR1 COM DAC SHIELD COM 30 1 FR2 COM 5 lt R32 RCOM 10 18 23 r 2 US 2 q FR4 COM HIGH SENSE CURRENT CANCELLATION 57904 1016 2 of 3 1 COM FR4 COM FR4 COM Figure 7 13 A16 DAC PCA cont 7 38 Schematic Diagrams 7 55 0 22 FRI DUTY CYCLE CONTROL CIRCUIT C109 cM 841 1 COM 0 22 18 FR1 LH COM 10K FR1 COM SECOND CHANNEL SWITCH DRIVE 30 FR1 COM 5 FAL CH1 SERIES A FIRST CHANNEL SERIES SWITCH 1000 FR1 DRIVER C103 33PF l i 1 FR4 COM FIRST CHANNEL SHUNT SWITCH DRIVER 5700 6303 CLOCK GENERATOR 1 COM l i i FR1 COM FRA COM 57904 1016 3 of 3 Figure 7 13 A16 DAC PCA cont 7 39 5790 F 5 DAC FILTER 30FR1 FR1 COM 2 LT1007CN8 C13 22UF REF COM FRI COM 18FR1 FR1 COM 1 30FR1 18FR1 VRI 15V 57904 1693 REF COM Ac 6 u1 OPO7CDR 4 3 18FR1 REF COM REF COM ED MICROFARADS 5790A 1093 Figure 7 14 A16A1 DAC Filter PCA 7 40 Schematic Diagrams 7
115. MYLAR STATIC SHIELD OPEN 0031 10 00 14 00 5700A 2056 SHIELD HIGH VOLTAGE REAR MP13 14 5790A 8024 FOAM THERMAL COVER P110 P210 CONNECTOR DIN41612 TYPE C M RT ANG 64 PIN FET PWR N IRFD120 TRANSISTOR SI N MOS 1W 4PDIP N JFET J310 ROSR TRANSISTOR SI N JFET TO 92 04 07 MOSFET SI N SD210 30V 50MA 45 OHMS 300MW DMOS LOW CAPACITANCE TO 72 BULK Q5 6 Q9 Q12 FET PWR N CHL R05A TRANSISTOR SI N DMOS PWR FET TO 92 MOSFET P CHANNEL TRANSISTOR SI P MOS ENHANCEMENT TO 72 010 TRANSISTOR SI PNP MAT03 36V 20MA 190MHZ DUAL TO 78 TRANSISTOR SI NPN LM394 20V 20MA DUAL TO 5 6 BULK Q101 N JEET TRANSISTOR SI N JFET SEL TO 92 RESISTOR R05A RES CF 390K 5 0 25W RESISTOR R05A RES CF 6 2M 5 0 25W RESISTOR RES MF 90 9 1 3W 25PPM RESISTOR R05A RES MF 499 1 0 25W 100PPM RESISTOR METAL FILM 806 1 0 25W 100PPM RADIAL TAPE R10 R31 R42 RESISTOR METAL FILM 150 1 0 25W 100PPM RADIAL TAPE R11 R20 RESISTOR ROSA RES MF 1K 1 0 25W 100PPM 6 38 442723 838458 152140 152165 376822 743229 875638 733063 910773 875356 820720 806521 797696 494724 680967 791921 893362 807800 853692 851972 394122 782565 741058 875752 640656 477448 706754 772327 886791 866686 810531 816595 N N N A N N N N N A N
116. RADIAL TAPE 830596 SET Pre al R22 R39 mm RESISTOR A52R RES MF 562 0 1 0 125W 25PPM we 1 RESISTOR A52R RES MF 19 6K 1 0 125W 100PPM 293746 1 EE R18 20 RESISTOR A52R RES MF 11 8K 0 1 0 125W 25PPM 3 R21 RESISTOR A52R RES MF 4 53K 1 0 125W 25PPM wem 1 RESISTOR A52R RES MF 40 2K 1 0 125W 100PPM 235333 1 RESISTOR A52R RES MF 3 92K 0 1 125W 25PPM 84462 1 RESISTOR A52R RES MF 39 2K 0 1 0 125W 25PPM 34457 1 R26 27 RESISTOR RO5A RES CF 4 7K 5 0 25W men 2 R29 RESISTOR A52R RES MF 10K 0 1 0 125W 25PPM 435065 RESISTOR A52R RES MF 2K 0 1 0 125W 25PPM 1 R33 RESISTOR A52R RES MF 124K 1 0 125W 100PPM 288407 1 R35 36 RESISTOR RO5A RES CF 750 5 0 25W 81034 2 C pres R38 R40 RESISTOR METAL FILM 68 1K 1 0 125W 100PPM AXIAL TAPE R41 RESISTOR A52R RES MF 147K 1 0 125W 100PPM 1 RESISTOR A52R RES MF 1 27K 1 0 125W 100PPM 26799 1 RESISTOR A52R RES MF 6 34K 1 0 125W 100PPM 2673 1 m n R45 RESISTOR A52R RES MF 63 4K 1 0 125W 100PPM 2352 1 C R47 RESISTOR A52R RES MF 17 4K 1 0 125W 100PPM 2602 1 kuma T wem 6 49 5790 6 50 OFFSET 0 4MHZ DIP8 TUBE OHMS SPST QUAD NC DIP16 TUBE D a OHMS SPST QUAD DIP16 TU
117. Related Terms Calibration Report A record of shifts or calibration constant changes that have occurred during calibration Calibrator A device that supplies outputs with a known uncertainty for use in testing the cury of measurement devices or other sources Charterization A calibration process that produces a calibration constant or known error for use in correcting the output or reading of an instrument or standard Common Mode Noise An undesired signal that exists between a device s terminals and ground Common mode noise is at the same potential on both terminals of a device Also see normal mode noise Compliance Voltage The maximum voltage that a constant current source can supply Confidence Level A percentage indicating certainty or assurance that an associated condition is true Control Chart A chart devised to monitor one or more processes in order to detect the excessive deviation from a desired value of a component or process Crest Ftor The ratio of the peak voltage to the RMS voltage of a waveform with the DC component removed Also see RMS DAC Digital to Analog Converter A device or circuit that converts a digital waveform to an analog voltage Derived Units Units in the SI system that are derived from base units Volts ohms and watts are derived from amperes and other base and derived units Distribution Function The expression of a relationship between the values and the correspondin
118. Replacable Parts 6 Parts Lists i aE T d F S 1845 m L NU Can 5790 1602 Figure 6 4 2 Front Panel PCA 6 21 5790 6 22 Table 6 6 Analog Motherboard eee Part mme mows C1 C3 CAPACITOR FILM POLYESTER 0 1UF 10 50V 5MM 649913 2 LS RADIAL TAPE CAPACITOR ROSR CAP TA 22UF 20 25V 845149 CAPACITOR RO5A CAP POLYES 0 001UF 10 50V 720938 EN CAPACITOR ROSR CAP CER 33PF 5 50V COG 714543 CR1 4 BRIDGE DB101 DIODE BRIDGE SI 50V 1A DIP 418582 Q SURGE PROTECTOR SURGE PROTECTOR 90V 20 198507 EG SPACER SPACER SWAGE 250 RND BR6 82 625 SPACER SWAGE 250 RND BR 6 32 625 877063 Ed ROUND 6 32 375 250 877019 OD BRASS SWAGE 094 PANEL THK o 20 CONNECTOR ACC CONN ACC DIN41612 KEY ACC CONN ACC DIN41612 KEY 832733 ME HEADER HEADER 1 ROW 156CTR 8 886812 HEADER HEA
119. Ro RESISTOR A52R RES MF 301 1 0 125W 100PPM 267740 R100 R104 R122 RESISTOR A52R RES MF 243 0 1 0 125W 50PPM 512228 4 R124 R103 RESISTOR 52R RES MF 110K 1 0 125W 100PPM 234708 GNE R118 RESISTOR A52R RES MF 10 1 0 125W 100PPM 268789 2 o R57 R6 R3 15 RESISTOR A52R RES CF 1 5K 5 0 25W 343418 6 29 5790 6 30 R129 R12 R17 RESISTOR A52R RES CF 2 4K 5 0 25W R134 135 RESISTOR A52R RES MF 34 8 1 0 125W 100PPM R136 RESISTOR A52R RES MF 84 5 1 0 125W 100PPM R137 R147 RESISTOR A52R RES MF 357 1 0 125W 100PPM R142 RESISTOR A52R RES MF 536 1 0 125W 100PPM R146 RESISTOR A52R RES MF 66 5 1 0 125W 100PPM 305987 R148 149 RESISTORAS2R RES CF 1 5 0 25W 357665 U1 U10 U12 BIFET LF412A IC OP AMP DUAL LO OFFST VOLT LO DRIFT 851704 U2 3 U5 AMP AD9618 5V 2 2MV OFFSET 130MHZ LO 886684 DISTORTION I FEEDBACK DIP8 TUBE BIPOLAR 7805 1 REG FIXED 5 VOLTS 1 5 AMPS 355107 BIPOLAR 317 IC VOLT REG ADJ 1 2 TO 37 V 1 5 AMPS 460410 EXE BIPOLAR LM337 IC VOLT REG ADJ NEG 1 2VTO 37V 1 5A 772996 EB c A 5 IC COMPARATOR NE521 5V 7 5MV OFFSET HI 556449 SPEED DUAL DIP14 TUBE BIPOLAR 393 0 COMPARATORDUALLO PWRBPINDIP 393 IC COMPARATOR DUAL LO PWR 8 DIP 478354 BIPOLAR 79051 ee VOLTS 1 5 AMPS 394551 5700A 4HO9T RMS CONVERTER TESTED 400 OHM A 842591 GRADE IC ANALOG SWITCH
120. SLOW FAST P1 10 GR2 1N4448 SLOW FAST 95 ua CA3096 17 95 8 42020 NOTES UNLESS OTHERWISE SPECIFIED 1 ALL RESISTORS ARE IN OHMS ALL CAPACITOR VALUES ARE IN MICROFARADS TESTPOINTS DESIGNATOR COMP OUT DIV OUT ue U4 JM1 EN Pas o COUNTER IN COUNTER OUT DIV 1 L C10 4 0 7 22 DIV N FILT JM1 U3 16 u2 1 03 1 85 14 330PF CR 483 MPS6544 R4 10 0K 06271 US 126 9627164 DIV OUT 6271 e16 2 1 COUNTER OUT 57904 1096 Figure 7 6 A6A1 RMS Support PCA Schematic Diagrams 7 5790 1697 17 5 Q2 2N22194 CRG R2 1D K amp 2 144443 1 5 684 a 2 120 144448 a N 4448 Qi R15 10K CRS 2 2905 12V 1 5549 4 7 25 184448 114448 UNLESS OTHERWISE SPECI ALL RESISTORS ARE IN O ALL CAPACITOR VALUES RE FIED HMS IN MICROFARADS 5790A 1097 Figure 7 7 2 WB Input Protection PCA 7 23 5790 MPT MPS 5 a x MP3
121. Set the 5700 to 0 2 V OPERATE Set the 845A to the 10 mV range Repeat nulling procedure of step 26 recording the 5700A Error Display indication opposite to 0 2 V in Table 3 3 Set the 5700A to STANDBY Set the 752A MODE switch to 0 1 V Repeat the procedure described in steps 26 through 29 for 5700A outputs of 0 06 0 06 0 02 and 0 02 V entering the Error Display indications in Table 3 3 Note It is not necessary to characterize the 5440B prior to performing the following steps in order to meet the test uncertainty requirements for the 57904 29 30 31 Set 5440B to output 0 6 V Repeat procedure described in steps 26 and 27 for 5700A outputs of 0 006 and 0 006 V entering the Error Display indications in Table 3 3 Set the 5440B to output 0 2 V Repeat the procedure described in steps 27 and 28 for 5700A outputs of 0 002 and 0 002 V entering the Error Display indications in Table 3 3 DC source characterization is now complete Set all outputs to standby and remove all connections Calibration and Verification 3 Periodic Calibration 3 16 DC Calibration Table 3 4 lists the equipment required for DC calibration of the main input Proceed as follows to perform DC calibration of the main input which is always the prerequisite for AC calibration Use the 5700A you characterized in the previous procedure as the DC source Table 3 4 Equipment Required for 5790A Main Input DC Calibratio
122. W OPEN COL 585224 ES RR Du EA UM 75162A B IC LSTTL OCTAL IEEE 488 BUS 686022 TRANSCVR CMOS 68C681 IC CMOS DUAL CHANNEL UART DUART 799494 EN 15KV ESD LOW POWER PDIP14 TUBE IC INTERFACE MAX1489E QUAD RS 232 LINE 1622769 RECEIVER 15KV ESD LOW IC COMPARATOR NES21 5V 7 5MV OFFSET HI 556449 SPEED DUAL DIP14 TUBE List of Replacable Parts 6 Parts Lists ZENER UNCOMP 1N750 4 7V 10 20MA DO 35 TAPE 387084 CONNECTOR SOCKET DIP 300CTR 24 PIN 812198 RESISTOR RES CERM SIP 10 9 RES 4 7K 2 484063 2 RESISTOR RES CERM SIP 6 PIN 5 RES 10K 2 500876 EHHH 1 Static sensitive part 6 73 5790 CAUTION SUBJECT TO DAMAGE BY STATIC ELECTRICITY 57904 1621 Figure 6 21 A21 Rear Panel PCA 6 74 Figure Egi gb aer AO OOV ON UA RO Ex r oco oc ipa ipa kau 7 22 Chapter 7 Schematic Diagrams Title Page ATiKeyboard PCA 7 3 2 Front Panel PCA eh 7 5 Analog Motherboard PCA 4 72 7 10 A4 Digital Motherboard 2 2 4 00 2 14 7 14 Wideband PCA 03 0 00 7 17 RMS Support PCA 0000 7 22 A6A2 WB Input Protection PCA
123. and Verification NG UJ WWW WW WWW 22 C2 C2 C2 WW WW Nd Ww Ww Ww Ww Ww HA LA b2 IS ID RR RF ND 090 Lh LA QAO DAE po paro SO pO oc Uy UA ax E A D Amplifier Assembly 15 Chopper Circuit A D Amplifier Circuits Digital Control and Power Supply DAC Assembly A16 DAC Assembly Reference Circuitry Duty Cycle Control Circuit DAC Filter Circuit DAC Output Stage Sense Current Cancellation Clircutt Linearity Control Circuit Negative Offset Wideband Module 6 Option 03 Input Signal Path for the Upper Four Ranges Input Signal Path for the Lower Four Ranges DC Offset Feedback for Amplifier U3 Lower Ranges RMS Sensor Circuit Transfer Methodology DC Offset Feedback for the RMS Sensor Amplifier Range Comparator Wideband Frequency Counter Digital Control 2 Input Protection Module Introduction sese Calibration Cycle Periodic
124. are normally low Setting OSC SET high stops the chopper in the inverting state Setting OSC RESET high stops the chopper in the non inverting state Chopper Switches This block provides a symmetrical square wave equal in RMS value to the DC input voltage 0 7 to 7 V A square wave is used instead of DC for making the transfers for two main reasons The square wave passes through AC coupled amplifiers on the wideband board while DC would be blocked by the coupling caps e Errors caused by DC offsets which add directly to a DC reference tend to average out with a dual polarity input Op amp U10 buffers the positive reference and Q3 increases current capability Resistor R11 biases Q3 and R10 provides current limiting IC U6 switches the output and sense alternately to a 20 dB divider Z6 or a dummy load R14 Similarly the components Q4 R12 R13 and U7 switch the negative reference between the dummy load and divider Chopper Attenuator This block selects the output level of the chopper by switching in 20 and 40 dB attenuators Total attenuation is e for the 2 2 V 22 V 220 V and 1000 V ranges neither attenuator in e 20 dB for 220 mV 700 mV 7 V 70 V and 700 V ranges 40 dB for 22 mV and 70 mV ranges e 60dB for 2 2 mV and 7 mV ranges both attenuators in Relay selects either 0 or 20 dB output from Z6 pin 3 or 1 Most of the current from this attenuator 15 cancelled by an opposite current in
125. for each range and adjusting the 5700A for the nominal value indication on the 5790A 3 65 5790 Service Manual HP 3458A DMM SEE TABLE 3 9 5700A CALIBRATOR FOR ATTENUATORS 5790A REQUIRED FOR EACH RANGE f WIDEBAND WIDEBAND INPUT outeur V E ATTEN TYPE N TEE 3 66 3 34 elu048 eps Figure 3 19 Wideband Verification Test Setup Part 2 Wideband Gain Verification 10 Hz to 500 kHz Gain errors at frequencies other than 1 kHz can be determined by adding the error measured at 1 kHz for that range to the error measured during wideband flatness verification See Table 3 16 3 35 Wideband Flatness Verification Proceed as follows to verify WIDEBAND input flatness l Characterize the AC source by following the procedure under the heading Characterizing the AC Source in Wideband Calibration procedure earlier in this chapter Use the Wideband Flatness Verification Worksheet Table 3 15 instead of Table 3 8 More frequencies are verified than are calibrated Connect the equipment as shown in Figure 3 13 The 5700A will be set to a nominal 3 2 V for all flatness verifications The only deviation from the nominal value will be for calibration corrections for the 5700 and the attenuators Table 3 9 shows the combinations of attenuators required to scale the input signal properly for each range r
126. found d bad block s Analog hardware control inoperative Bad Syntax Unknown command 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1337 1338 1339 1360 1361 1362 1363 1364 1365 1366 1368 1369 1370 1500 1501 1502 1602 1603 1604 1605 Maintenance 4 Error Codes Bad parameter count Bad keyword Bad parameter type Bad parameter unit Bad parameter value 488 2 I O deadlock 488 2 Interrupted Query 488 2 Unterminated command 488 2 Query after indefinite response Invalid from GPIB interface Invalid from serial interface Service Only Parameter tool long Invalid device trigger DDT recursion Macro calls too deep Already executing a procedure Already writing to NV memory MEAS timed out Bad binary number Bad binary block Bad character Bad decimal number Exponent magnitude too large Bad hexadecimal block Bad hexadecimal number Bad octal number Too many characters Bad string Invalid time Invalid date Can t set date CAL STORE switch NORMAL Bad reply size from inguard False MSG semaphore from inguard Inguard CPU A D error Inguard CPU timer out on main CPU 4 15 5790 1606 1607 1608 1609 1610 1611 1612 1613 1700 1701 1702 1703 1704 1705 1900 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2201 2202 2203 2204 2205 2206 2207 2208 2209
127. generates precisely variable DC for the AC DC transfer Anultra stable DC voltage reference establishes DAC accuracy A DC to square wave converter chops the DAC output to eliminate DC reversal error in the RMS sensor Functional Block Diagram Discussion Refer to part 1 of Figure 2 1 the functional block diagram The AC signal to be measured is applied to the FTS first through attenuators precision resistor networks switched in or out depending on range the transfer switch and precision amplifiers again depending on range The A D Amplifier A15 assembly measures the output of the FTS In the block diagram this measurement 15 called M1 The next step in the transfer process is shown in part 2 of Figure 2 1 The system takes another measurement called M2 The CPU sets the precision DAC digital to analog converter to approximately the same voltage as the output of the divider network for This voltage is converted to a 28 Hz square wave by the precision chopper circuit and applied to the FTS through the transfer switch and the same range amplifier The output of the FTS is measured again to yield M2 In Wideband mode the option 5790 03 Wideband module takes over the function of the Transfer assembly The chopped reference from the A D Assembly is 80 Hz for Wideband mode The Wideband assembly is AC coupled therefore does not make AC DC transfers 2 5 5790 Service Manual 2 6 Refer to the flowchart part
128. gt CONVERTER CPU FTS CIRCUIT AND FILTERS OUTPUT FROM A10 TRANSFER ASSEMBLY FROM FTS gt SWITCHABLE FREQUENCY CIRCUIT LPF gt COUNTER CPU INPUT CPU elu010 eps Figure 2 8 A15 A D Amplifier Block Diagram Null DAC The Null DAC 15 set by the CPU to equal the A D measurement taken with the instrumentation amplifier on the X1 setting the first pass This measurement shows on the display as the reading with lower resolution and the U indicator lit This DAC has a 14 bit resolution where 0 counts gives 0 V hex counts gives 42 2 V full scale After the first pass the instrumentation amp is set to X10 and the input signal is offset with the Null DAC to get higher resolution readings The Null DAC circuit has a high degree of short term stability which is the critical parameter in its application IC U16 is an R 2R ladder DAC using an internal feedback resistor and external op amp 017 Since U16 is an R 2R ladder DAC it injects a current which varies with DAC counts into the ground IC U23 buffers R COM to control the current from U16 preserving the DAC linearity A 0 5 mA reference current is produced by U23 pins 5 and 6 and R18 through 20 This current biases 6 4 V zener VR6 71 pins 1 through 3 divide down the zener voltage to provide a 1 V reference for U24 U27 pins 5 through 7 and R20 and R21 form an inverting amplifier that provides a 2 5 V reference for
129. in the table for use in steps 16 and 26 Set the 5790A to WBND and the 220 mV range Set the 5700A to 3 2 V at 1 kHz operate The 5790A will read approximately 100 mV elu042 eps Calibration and Verification 3 Service Calibration SELECT SWITCHES L RS232 Q I 21 PANEL 000000 18 FILTER PCA A17 REGULATOR GUARD CROSSING 16 A15 A D AMPLIFIER ACCESS HOLE THROUGH GUARD COVER lt A22 POWER TRANSFORMER e A10 TRANSFER PCA 1 NI A19 DIGITAL POWER SUPPLY PCA 20 24 U 6 2 A6 WIDEBAND WIDEBAND A4 DIGITAL 1 SHIELD COVER MOTHER BOARD A2 FRONT PANEL PCA U 11 1 KEYBOARD ASSEMBLY elu040 eps Figure 3 14 Location of R27 Transfer and C20 and C24 Wideband 3 41 5790 Table 3 11 Wideband Amplifier Rolloff Adjustment Worksheet Gees 4 Attenuator 2 Eror PM 002 __ 13 Allow 55 stabilize and
130. instructions A complete list of Service Centers appears at the end of Chapter 6 To reship the 5790A use its original shipping carton If the original carton is not available use a container that provides adequate protection during shipment Protect the 5790A with at least three inches of shock absorbing material on all sides of the container Do not use loose fill to pad the shipping container Loose fill allows the instrument to settle to one corner of the shipping container which could result in damage during shipment 1 3 Symbols Table 1 1 lists the symbols used on the instrument and or in this manual Table 1 1 Symbols e ro 5790 Service Manual 1 4 1 4 1 7 Safety Instructions Please read this chapter carefully It will familiarize you with important safety instructions for handling your 5790A instrument In this manual a Warning identifies conditions and actions that pose hazard s to the user A Caution identifies conditions and actions that may damage the test instrument The instrument is designed and tested in accordance with IEC Publication 348 Safety Requirements for Electronics Measuring Apparatus 5790A If the instrument is used improperly there is risk damage to persons and property Input Source Limits To avoid electrical shock or fire connect the input terminals only to sources that do not exceed 1000 V RMS or DC and that cannot exceed 200 mA operational or short circuit current
131. lethal voltages Use extreme caution to avoid contact with live conductors Set the calibrator to standby and verify that voltage has returned to zero immediately after each high voltage calibration step is finished elu027 eps Note For the 200 mV points and below remove the external sense leads and set the 5700A to INT SENSE 12 Continue until the DC calibration is finished Table 3 5 lists the steps in periodic calibration of the main input The 2 2 mV range 15 the last DC calibration step Table 3 5 Calibration Steps in Periodic Calibration Tolerance Calibration Purpose of tep N Volt to Appl to Source PPM Calibration Step Calibrates DACs and Basic DC 2 V DC thermal sensor This is the unscaled range Sensor turnover 0 7 0 7 V DC Corrects turnover error of the HMS sensor minimum scale After the Sensor turnover 0 7 0 7 V DC 0 7 V step internally calibrates the range zeros 1000 V Positive 1000 V Negative 700 V Positive 700 V Negative DC 220 V Positive DC 220 V Negative DC 70 V Positive DC 70 V Negative DC 22 V Positive DC 22 V Negative DC 7 V Positive DC 7 V Negative DC 2 2 V Positive DC 2 2 V Negative DC 700 mV Positive DC 700 mV Negative DC 220 mV Positive DC 220 mV Negative DC 70 mV Positive DC 70 mV Negative DC 22 mV Positive DC 22 mV Negative DC 7 mV Positive DC 7 mV Negative DC 2 2 mV Positive DC 2
132. offset of limits 122 CAL Divide by zero 5 IA update 123 CAL Old s 15 WAY OFF 124 CAL Temperature gain is zero 125 CAL New temperature Zero out of limits 126 CAL CAL switches must ENABLE SERVICE 127 128 199 200 201 202 300 301 302 303 304 400 401 402 403 404 405 406 407 408 409 410 41 412 413 414 415 416 417 418 419 420 421 422 423 500 CAL CAL CAL IG IG IG IG IG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG DIAG STA Maintenance 4 Error Codes INPUT2 Correction factor out of limits Calibration step in progress Cal error occurred Already reported Need to do that Need Wideband AC option to do that IG Software out of date Use s or newer A17 guardcrossing ROM checksum A17 guardcrossing RAM A17 guardcrossing DUART A17 guardcrossing Watchdog Hardware initialization S A16 DAC s channel S A15 A D s self test A15 A D s Zero A15 A D Null DAC s A15 A D DAC s A15 A D Chopper s A10 Transfer s Range A10 Transfer s Protection check A10 Transfer Overload check A10 Transfer Sensor input output match A10 Transfer s Range Zero A10 Transfer s Input path A10 Transfer s Frequency measurement Wideband 905 Range Wideband Overload check Wideband s Frequency measu
133. on the Front Panel assembly Refer to the Keyboard schematic for the name of the signal line that controls each keycap LED 2 25 5790 Service Manual 2 48 Analog Section Detailed Circuit Description Detailed descriptions of each assembly in the analog section are provided in this section Simplified schematics are provided to supplement the text 2 49 Filter Assembly A18 The Filter assembly receives AC inputs from the main power transformer secondaries and provides unregulated DC to the Regulator Guard Crossing assembly A17 and regulated DC supplies to the DAC assembly The unregulated supplies are listed in Table 2 8 and the regulated supplies are listed in Table 2 9 Table 2 8 Unregulated Supplies from the Filter Assembly Signal Name Nominal Tolerance eee Rated Output Test Point Output Ripple E DR pev pm mum m mum m mum mum ire mee Dem Dew I 2 26 Theory of Operation 2 Analog Section Detailed Circuit Description Table 2 9 Regulated Supplies from the Filter Assembly Signal Name Palia Current Limit Rated Output Test Point 2 50 Unregulated CH Supplies Line CH COM 15 the return path for the 15 CHR and 15 CHR supplies These supplies use a full wave center tapped configuration They consist of a bridge rectifier CR3 and two filter capacitors C4 and 6 for
134. on the upper four Wideband ranges 7 V 2 2 V 700 mV and 220 mV pass through relays and to resistor network Z1 which provides 50 load The input signal is also sensed by the A6A2 Input Protection module through diodes and CR31 for positive voltages and through CR5 and CR30 for negative voltages Resistor network Z1 attenuates the upper four ranges 10 dB and passes the signal to relays K7 K2 K3 K8 and attenuator Z2 which has switchable 10 dB and 20 dB sections The relays configure attenuator Z2 for the upper four ranges as necessary to produce a 70 mV full scale input to buffer amplifier U5 The relays configure Z2 as follows e 7V range With 7 V input K7 K2 K8 are reset which switches in both 10 dB and 20 dB sections of Z2 into the path providing 30 dB of attenuation With a 7 V input to 10 dB attenuator Z1 the output of Z2 is therefore at 70 mV 22V range Relays K7 and K2 bypass the 10 dB section of Z2 A 2 2 V input results in a 70 mV RMS signal at the RMS sensor amplifier input Q6 and US which is the same full scale value as in the 7 V range 700 mV range Relays K7 and K2 switch in the 10 dB section of Z2 and relays K3 and bypass the 20 dB section of Z2 A full scale input of 700 mV gives 70 mV full scale at the RMS sensor amplifier input Q6 and U5 220 mV range Relays K7 K2 and K8 bypass both 10 dB and 20 dB sections of Z2 to give 70 mV full scale at the RMS sensor input
135. right to invoice Buyer for importation costs of repair replacement parts when product purchased in one country is submitted for repair in another country Fluke s warranty obligation is limited at Fluke s option to refund of the purchase price free of charge repair or replacement of a defective product which is returned to a Fluke authorized service center within the warranty period To obtain warranty service contact your nearest Fluke authorized service center to obtain return authorization information then send the product to that service center with a description of the difficulty postage and insurance prepaid FOB Destination Fluke assumes no risk for damage in transit Following warranty repair the product will be returned to Buyer transportation prepaid FOB Destination If Fluke determines that failure was caused by neglect misuse contamination alteration accident or abnormal condition of operation or handling including overvoltage failures caused by use outside the product s specified rating or normal wear and tear of mechanical components Fluke will provide an estimate of repair costs and obtain authorization before commencing the work Following repair the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges FOB Shipping Point THIS WARRANTY IS BUYER S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIE
136. rms Step Step La La La elu031 eps Press the DO Step softkey The display changes to Calibration LF 10 Hz Linearity ENTER the exact value to do step Apply 2 0V rms Voltage 2 000000 Last Prev Entry Menu a a elu032 eps For all the cal points down to 70 mV range use the Fluke 792 AC DC Transfer Standard to adjust the AC voltage level being applied to the 5790A INPUT connector There are three procedures for AC calibration points depending on their amplitude Go to the appropriate step as defined below Step 6 2 V through 600 V Step 7 60 mV through 600 mV Step 8 2 mV through 20 mV For an AC calibration point in the 2 V through 1000 V range proceed as follows a Obtain a copy of Figure 3 6 the worksheet for this group Fill in the test voltage and frequency and the associated 792A correction b Ifthe test voltage is above 220 V add the 792A 1000 V range resistor to the test setup as shown in Figure 3 8 c Press the DO Step softkey This automatically selects the correct 5790 range d Set 792A INPUT RANGE knob to the appropriate position Always use the lowest range that will accept the input 3 23 5790 3 24 Caution Always ensure that proper range has been selected before applyin
137. sheet which when applicable is included with the manual 6 3 5790 Service Manual 6 4 Table 6 1 Manual Status Information Ref or Option Fluke Part Revision No Assembly Name No Level A1 Keyboard PCA 880687 B A2 Front Panel PCA 85587 105 A3 Analog Motherboard PCA 885590 100 A4 Digital Motherboard PCA 885595 102 A6 Wideband PCA Option 03 885660 109 A6A1 RMS Support PCA 893268 D A6A2 WB Input Protection PCA 893271 100 A10 Transfer PCA 885603 110 A10A1 Precision Amplifier PCA 893300 101 A10A2 High Voltage Protection Amplifier PCA 893305 102 A10A3 High Gain Precision Amplifier PCA 893313 106 A15 A D Amplifier PCA 885608 105 A16 DAC PCA 885611 105 A16A1 DAC Filter PCA 893276 C A17 Regulator Guard Crossing PCA 874859 105 A18 Filter PCA 885616 104 A19 Digital Power Supply PCA 885624 104 A20 CPU PCA 885629 114 A21 Rear Panel I O 885632 102 Service Centers A list of service centers 15 located on www fluke com Parts Lists The parts lists are provided on the following pages Table 6 2 Final Assembly List of Replacable Parts Parts Lists Ref Des Description Tu Qty Notes A1 KEYBOARD PCA 880687 1 4 A2 FRONT PANEL PCA 885587 1 4 A3 ANALOG MOTHERBOARD PCA 885590 1 4 A4 DIGITAL MOTHERBOARD PCA 885595 1 4 A10 TRANSFER ASSY PCA 885603 1 4 A15 A D AMPLIFIER PC
138. the other ICs on the assembly A 5 2 V supply for U7 is provided by VRS with C64 acting as the supply bypass Refresh Failure Deject Circuitry If a clock failure were to occur the refresh cycles of the vacuum fluorescent displays would be interrupted This condition could damage the tubes if not immediately detected Refresh failure detect circuitry monitors the GRIDDATA output from the last high voltage driver U23 for the Control Display This output REFRESH is used to clear a watchdog timer U6 during every refresh cycle If the refresh is interrupted and GRIDDATA does not occur the watchdog timer times out and latches U12 Flipflop U12 generates control lines 75VSD and Control line 75 VSD is routed to the Digital Power Supply assembly to shut down the 35 V and 75 V power supplies thus preventing damage to the vacuum fluorescent displays Interrupt line PSFAILINTR is used by PLD U3 to properly blank the Control Display and 2 21 5790 Service Manual 2 22 2 42 Measurement Display through DMDBLANK and OTDBLANK and alerts the CPU that this failure has occurred Decoding and Timing Circuitry Main decoding and master timing functions for the Front Panel are accomplished by an EP900 PLD Programmable Logic Device U3 Two state machines control display refresh and filament switching Filament switching is handled by two non overlapping 57 6 kHz signals Signals GSTRBE and STROBE are master
139. the same power dissipation in a resistance as a DC current or voltage of the same value RMS Sensor A device that generates a DC output signal proportional to the RMS value of the input signal RMS sensors operate by measuring the heat generated by a voltage through a known resistance i e power therefore they sense true RMS voltage RMS sensors are used to make AC DC difference measurements Scale The absolute span of the reading range of a measurement device including overrange capability Scale Error See gain error Secondary Standard A standard maintained by comparison against a primary standard Sensitivity The degree of response of a measuring device to the change in input quantity or a figure of merit that expresses the ability of a measurement system or device to respond to an input quantity 5790 Settling Time The time taken for a measurement device s reading to stabilize after a voltage 15 applied to the input Shield A grounded covering device designed to protect a circuit or cable from electromagnetic interference Also see guard SI System of Units The cepted International System of Units See also units base units and derived units Specifications precise statement of the performance of a measurement or stimulus device Square Law Defines the response of a device whose output 1 proportional to the square of the applied stimulus
140. to input of sensor to output of sensor 5 12 Troubleshooting Introduction Test Step MATCH Sensor Match 19 5 20 ma This tests that input and output sections of the RMS sensor match The test proceeds as follows Configure instrument in 2 2 V range with no input Hook chopper to Transfer assembly stopped in the high state Configure DAC to output 1 0 Be IW ge Measure output of sensor via RCL Connect input of sensor to RCL instead of output The error from this test 1s Error Code 3011 A10 Transfer Sensor Input Output Match Failed This error indicates a fault on A10 Transfer assembly Check the input and output voltages on the sensor Should both be approximately the same If they differ the RMS sensor itself is most likely bad part elu067 eps Test Step XFREQ Frequency Measuring This measure the chopper frequency via the Transfer assembly The Transfer assembly is configured for the 2 2 V range with no input The error from this test 1s Error Code 3014 A10 Transfer Frequency Measurement Failed elu068 eps This error indicates that a fault probably exists on the A10 Transfer assembly or less likely on the A15 A D Amplifier assembly Check that the chopper AC signal is being transmitted to A10 Transfer assembly Trace through the amplifiers to the input of sensor From there the chopped reference is switched onto the COUNT motherboard line back to the 15 A D Amplifier assembl
141. when the display asks for it The 5700A will need to be set to about 600 mV due to the 30 dB of attenuation Press the 70 mV range key and measure and record the value Press the DO STEP softkey and enter the number just measured on the 70 mV range Now press the ENTER key and the 5790A will calibrate the 22 mV range and step to the 7 mV calibration display Calibrate the 7 mV range by applying 6 mV at 1 kHz and then pressing the 22 mV range key to measure and record the value Press the DO STEP softkey and enter the value just measured on the 22 mV range Press the ENTER key 20 21 3 21 Calibration and Verification 3 Periodic Calibration and the 5790A will calibrate the 7 mV range and step to the 2 2 mV calibration display The 2 2 mV range is done in a similar manner by reading the value on the 7 mV range and entering the value when requested and then pressing the ENTER key The absolute calibration on all ranges is now complete and the 5790A is ready for flatness calibration Calibrating Wideband Input Flatness The wideband source characterization must be done within 30 minutes of beginning flatness calibration Before you start make 8 copies of Table 3 8 with the 5700A error column filled in Recorded entries into the 5700A error column during in the first part of WIDEBAND calibration l 2 Connect the equipment as shown in Figure 3 13 5700A CALIBRATOR 5790A ATTEN WIDEBAN
142. 0 to standby Repeat the previous steps 1 through 5 for the other 22 mV range point s b Calibrate the 7 mV range as follows 1 2 3 4 5 6 Lock 5790 22 mV range 792 may left attached although it 15 not used Apply the requested voltage and frequency When the reading on the 5790A Measurement Display settles record the reading Press the DO Step softkey This automatically selects the 7 mV range Enter the value you recorded in step 2 and press the ENTER softkey When the step is completed set 5700A to standby Repeat the previous steps 1 through 5 for the other 7 mV range point s c Calibrate the 2 2 mV range as follows 1 2 3 Lock 5790 in 7 mV range The 792A may be left attached although it 15 not used Apply the requested voltage and frequency When the reading on the 5790A Measurement Display settles record the reading Press the DO Step softkey This automatically selects the 2 2 mV range Calibration and Verification 3 Periodic Calibration 4 Enter value you recorded in step 2 and press the ENTER softkey 5 When step 15 completed set the 5700 to standby 6 Repeat the previous steps 1 through 5 for the other 2 2 mV range point s 9 When you finish the calibration the display appears as follows Done Store Calibration is complete Print With Cal Shift Cal Consts Report a
143. 0 10 Hz 20 Hz 80 1 3 83 1 3 86 1 3 20 Hz 40 Hz 33 1 3 39 1 3 45 1 3 40 Hz 20 kHz 29 1 3 36 1 3 42 1 3 7 20 kHz 50 kHz 40 2 0 4 2 0 63 2 0 50 kHz 100 2 53 2 5 57 2 5 72 2 5 100 kHz 300 kHz 110 4 0 130 4 0 210 4 0 300 2 500 2 370 6 0 450 8 0 740 8 0 500 kHz 1 MHz 1600 6 0 2000 8 0 3400 8 0 10 Hz 20 Hz 69 1 3 72 1 3 75 1 3 20 Hz 40 Hz 34 1 3 40 1 3 46 1 3 40 Hz 20 kHz 30 1 3 36 1 3 43 1 3 22 20 kHz 50 kHz 40 2 0 45 2 0 64 2 0 50 kHz 100 kHz 53 2 5 57 2 5 73 2 5 100 kHz 300 kHz 97 4 0 110 4 0 160 4 0 300 2 500 2 310 6 0 380 8 0 610 8 0 500 kHz 1 MHz 1200 6 0 1500 8 0 2500 8 0 10 Hz 20 Hz 60 1 5 61 1 5 62 1 5 20 Hz 40 Hz 27 1 5 30 1 5 37 1 5 40 Hz 20 kHz 22 1 5 25 1 5 34 1 5 70 20 kHz 50 kHz 34 2 0 36 2 0 44 2 0 50 kHz 100 kHz 53 2 5 54 2 5 62 2 5 100 kHz 300 kHz 110 4 0 120 4 0 170 4 0 300 kHz 500 kHz 270 6 0 290 8 0 320 8 0 500 kHz 1 MHz 910 6 0 970 8 0 1200 8 0 10 Hz 20 Hz 55 60 1 5 61 1 5 62 1 5 20 Hz 40 Hz 20 27 1 5 29 1 5 35 1 5 40 Hz 20 kHz 17 22 1 5 24 1 5 31 1 5 220 20 2 50 2 17 22 2 0 24 2 0 33 2 0 50 kHz 100 kHz 51 2 5 52 2 5 59 2 5 100 kHz 300 kHz 100 4 0 120 4 0 170 4 0 300 2 500 2 260 6 0 290 8 0 310 8 0 500 kHz 1 MHz 890 6 0 950 8 0 1
144. 0 0 4 300 0 5 400 30 Hz 120 Hz 0 03 40 0 3 200 0 4 300 0 5 400 120 Hz 1 2 kHz 0 03 40 0 3 200 0 4 300 0 5 400 1 2 kHz 120 kHz 0 03 40 0 3 200 0 4 300 0 5 400 700 mV 120 kHz 500 kHz 0 03 40 0 3 200 0 4 300 0 5 400 10 0 500 kHz 1 2 MHz 0 05 40 1 2 MHz 2 MHz 0 05 75 2 MHz 10 MHz 0 1 100 10 MHz 20 MHz 0 15 100 20 MHz 30 MHz 0 35 200 10 Hz 30 Hz 0 10 40 0 3 300 0 35 400 0 4 500 30 Hz 120 Hz 0 03 40 0 3 300 0 35 400 0 4 500 120 Hz 1 2 kHz 0 03 40 0 3 300 0 35 400 0 4 500 1 2 kHz 120 kHz 0 03 40 0 3 300 0 35 400 0 4 500 22 V 120 kHz 500 kHz 0 03 40 0 3 300 0 35 400 0 4 500 10 0 uV 500 kHz 1 2 MHz 0 05 40 1 2 MHz 2 MHz 0 05 75 2 MHz 10 MHz 0 1 100 10 MHz 20 MHz 0 15 100 20 MHz 30 MHz 0 35 200 10 Hz 30 Hz 0 10 40 0 3 500 0 35 800 0 4 1000 30 Hz 120 Hz 0 03 40 0 3 500 0 35 800 0 4 1000 120 Hz 1 2 kHz 0 03 40 0 3 500 0 35 800 0 4 1000 1 2 kHz 120 kHz 0 03 40 0 3 500 0 35 800 0 4 1000 120 500 2 0 03 40 0 3 500 0 35 800 0 4 1000 100 0 uV 500 2 1 2 2 0 05 40 1 2 MHZ 2 MHZ 0 05 75 2 MHz 10 MHz 0 1 100 10 MHz 20 MHz 0 15 100 20 MHz 30 MHz 0 35 200 1 Range limits same as INPUT 1 or INPUT 2 Relative to 1 kHz for 2 year specification multiply by 1 5 3 Add to flatness specifications when more than C from calibration temperature 4 At input connector 5790
145. 0 DC Resistance Cable Assy 18 a N Facilitate connection to DMM for 1 kHz M to Type N F 4496 T 18 or eq iValent Wideband Gain verification Adapter Type N Facilitate connection to DMM for 1 kHz Double Banana Pomona 1740 orequivalent Wideband Gain verification Frequency counter Frequency counter x C PM6 5ppm 5ppm Frequency Uncertainty or Better Uncertainty or 5ppm Frequency Uncertainty or Better E Digital Equipment VT 100 RS 232 Serial communication 1 See Table 3 16 IF USING METHODS OTHER THAN SPECIFIED MAX UNCERT for specific Voltage Frequency and Uncertainty information 2 The JFW attenuators must be characterized by Fluke see text 3 Required only for Service Calibration 3 28 Calibration and Verification 3 Periodic Calibration Table 3 8 Wideband Calibration Worksheet Range 1 kHz A55 5790A 5700A 10dB 20dB 20dB 20 dB Total Ref Frequency Corr Error Error Error Error Error Error Error Error PPM PPM PPM PPM PPM PPM PPM PPM Enter Once ___ 3 19 Characterizing AC Source meet test uncertainty requirements for WIDEBAND input calibration you must first characterize the AC source to be used in the procedure The attenuators must be characterized before use You must characterize the source and calibrate the WIDEBAND input in a temperature controlled room The A55 Therma
146. 00 1000 0100 1001 0100 1010 0100 1011 0100 1100 0100 1101 0100 1110 0100 1111 Appendices ASCII and IEEE 488 Bus Codes Message ATN True TALK ADDRESSES B 5790 Binay ASCII Message ATN True Char 7654 3210 80 120 0101 0000 121 0101 0001 122 0101 0010 na 123 0101 0011 124 0101 0100 125 0101 0101 126 0101 0110 127 0101 0111 130 0101 1000 131 0101 1001 132 0101 1010 133 0101 1011 134 0101 1100 135 0101 1101 136 0101 1110 137 0101 1111 140 0110 0000 141 0110 0001 142 0110 0010 143 0110 0011 144 0110 0100 145 0110 0101 0110 0110 2 OJO o 0110 0111 81 82 T U V W x Y 2 b 9 f g 0110 1000 0110 1001 0110 1010 SECONDARY ADDRESSES 0110 1011 a gt WAIN O Q AJO N a 0110 1100 0110 1101 0110 1110 0110 1111 ASCII Char 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 160 161 162 163 164 165 166 167 170 171 172 173 174 175 176 177 7654320 0111 0000 0111 0001 0111 0010 0111 0011 0111 0100 0111 0101 0111 0110 0111 0111 0111 1000 0111 1001 0111 1010 0111 1011 0111 1100 0111 1101 0111 1110 01111111 Appendices ASCII and IEEE 488 Bus Codes Message ATN True B 5790 6
147. 00 200 20 Hz 40 Hz 63 67 68 72 40 Hz 20 kHz 25 30 32 39 20 kHz 50 kHz 55 56 57 63 50 kHz 100 kHz 91 94 110 100 kHz 300 kHz 190 200 220 300 kHz 500 kHz 400 410 510 500 kHz 1 MHz 1100 1200 1500 10 Hz 20 Hz 200 200 200 200 20 Hz 40 Hz 63 67 68 72 40 Hz 20 kHz 23 29 31 38 220 V 20 kHz 50 kHz 63 67 69 77 50 kHz 100 kHz 96 98 110 100 kHz 300 kHz 210 210 260 300 kHz 500 kHz 440 500 700 10 Hz 20 Hz 200 200 200 200 20 Hz 40 Hz 92 96 99 110 700 V 40 Hz 20 kHz 36 39 41 47 20 kHz 50 kHz 120 130 150 50 kHz 100 kHz 400 500 850 10 Hz 20 Hz 200 200 200 200 20 Hz 40 Hz 92 96 99 110 1000 V 40 Hz 20 kHz 33 37 38 44 20 kHz 50 kHz 120 130 150 50 kHz 100 kHz 400 500 850 2 9 5 to 10 Hz specifications is 1000 of reading 1 7 5790 Service Manual Relative Uncertainty Specifications 5 C of Calibration Temperature Voltage Range Frequency Range Relative Uncertainty ACIDC Transfer Measurement Mode Mode ppm ppm of Reading uV 2 Years 90 Days 1 Year 2 Years 10 Hz 20 Hz 100 1 3 110 1 3 110 1 3 20 Hz 40 Hz 54 1 3 64 1 3 68 1 3 40 Hz 20 kHz 44 1 3 57 1 3 61 1 3 22 20 kHz 50 kHz 57 2 0 67 2 0 110 2 0 50 kHz 100 kHz 79 2 5 86 2 5 120 2 5 100 kHz 300 kHz 190 4 0 230 4 0 390 4 0 300 2 500 2 590 6 0 720 8 0 1200 8 0 500 kHz 1 MHz 2200 6 0 2600 8 0 4400 8
148. 00 V DC 60 V DC 20 V DC 6 V DC 2 V DC 600 600 mV DC 200 mV DC 200 mV DC 60 mV DC 60 mV DC 20 mV DC 20 mV DC 6 mV DC 6 mV DC Tolerance of Calibration Source PPM Purpose of Calibration Step Calibrates DACs and thermal sensor This is the unscaled range Corrects DC turnover error Corrects turnover error of the HMS sensor minimum scale After the 0 7 V step internally calibrates the range zeros Establishes gain and DC offset for the 1000 V range Establishes gain and DC offset for the 700 V range Establishes gain and DC offset for the 220 V range Establishes gain and DC offset for the 70 V range Establishes gain and DC offset for the 22 V range Establishes gain and DC offset for the 7 V range Establishes gain and DC offset for the 2 2 V range Establishes gain and DC offset for the 700 mV range Establishes gain and DC offset for the 220 mV range Establishes gain and DC offset for the 70 mV range Establishes gain and DC offset for the 70 mV range Establishes gain and DC offset for the 7 mV range Calibration and Verification 3 Service Calibration Table 3 10 Calibration Steps in Service Calibration cont Step Name 2 2 mV Positive DC 2 2 mV Negative DC 700 V 12 1 100 kHz Input 1 700 V 12 1 100 kHz Input 2 22 V 12 11 1 MHz Input 1 22 V 12 11 1 MHz Input 2 2 2 V 1211 1 MHz Input 1 2 2 V 2
149. 00PPM 1206 7460356 1 RESISTOR SMR RES CERM 124 1 125W 100PPM 1206 899 2 RESISTOR CERMET 432 1 0 25W 100PPM 1206 TAPE 811885 2 us a prem sss Ls ara m sss IRR OFFSET 140MHZ WIDEBAND W DISABLE DIP8 TUBE VRA1 VR2 ZENER UNCOMP MMBZ5231B 5 1V 5 20MA 225MW SOT 837179 2 23 TAPE ZENER UNCOMP BZX84C12 12V 5 5MA 225MW SOT 23 TAPE 866822 lt 1 1 1 ZENER UNCOMP MMBZ5248B 18V 596 7MA 225MW SOT 23 TAPE 876433 VR10 ZENER UNCOMP IN746 33V 10 20MA DO 35 TAPE 309799 4 Static sensitive part 1 Eze CR1 CE 5 m 00 cip R14 uR Gy gs l 09 CR4 _ 5 gt C SE 50008 Figure 6 13 High Gain Precision Amplifier 5790A 1695 List of Replacable Parts Parts Lists 6 6 47 5790 6 48 Table 6 15 15 A D Amplifier Part Ref Des Description t ape RPM 1 2 4 CAPACITOR FILM POLYESTER 0 22UF 5 50V 5MM 747519 C23 C25 LS RADIAL TAPE C44 C3 C21 CAPACITOR 1000PF 20 50V X7R 697458 Ca CAPACITOR R05A CAP POLYES 1UF 10 50V 733089 C7 8 C12 CAPACITOR ROSR CAP TA4 7UF 20 25V 807644 4 13 ENG C14 CAPACITOR ROSA CAP POLYES 0 01UF 10 50V 715037 s a CAPACITOR R05R CAP CER 4 7PF 0 25PF 50V C0G 721837 CAPACITOR RO5R CAP CER 470PF 5 50V COG 830430 15 16 CAPACITO
150. 1 023 40 SD Ut8 43 PAL_IMAGE TTT QI UG QU SS X D de OE Hs WON Gl Gros Ro a Onde y3 6 5 DMOCS TP23 TP22 TP10 11 1 02 2 8 ENCODERCS 124 3 I D3 9 ENCODERRESET trast 10 LED LATCH 910 11 CONNECTOR TQ CPU VIA CABLE 1 7 Ios H KEYBOARDGS 0855 3 4 12 FPR TAC 5v Wt ijo 12 013 3 8 5v i 5 1708 CESE z1 4 4 7K FRAG L a FRAR Ex 1 010 U11 FRNIPNLOS 1 011 24 1 012 5 LEDENABLE 010 1 tSv BUSYO 28 Iota _ A amp 5 T BUSYD 1 014 OTDBLANK 14 212 DMDBLANK _ E ME iE 1 016 020 21 28 2 _ 1 056 9 FPD 43 1 01 1 1 0 B All EPDE 17019 5 A12 FPD 1 020 STROBE Y S 14 42 018 21 REFRESH FAILURE DETECT CIRCUITR 480 8KHz 1 022 116 21 Alb 17023 40 ALS 4 R71 A PAL IMAGE 18 PAG 82K PF CEPAT A20 74H040600T A21 TP24 TP34 12 REFRESH 923 2 N MICROFARADS FRNTPNLCS 60 8KHZ
151. 1 1 MHz Input 2 Frequency Adjustment LF 10 Hz Linearity LF 10 Hz Linearity 1 kV AC 1 kHz 1 kV AC 20 kHz 1000 V AC 100 kHz 700 V AC 1 kHz 700 V AC 20 kHz 700 V AC 100 kHz 220 V AC 1 kHz 220 V AC 20 kHz 220 V AC 300 kHz Voltage to Apply 219 V RMS 100 kHz 219 V RMS 100 kHz 1 20 V RMS 1 MHz 20 V RMS 1 MHz 2 0 V RMS 1 MHz 2 0 V RMS 1 MHz 2V rms 1 kHz measure with PM6666 counter 2 V RMS 10 Hz 0 6 V RMS 10 Hz 1000 V RMS 1 kHz 1000 V RMS 20 kHz 1000 V RMS 100 kHz 600 V RMS 1 kHz 600 V RMS 20 kHz 200 V RMS 100 kHz 200 V RMS 1 kHz 200 V RMS 20 kHz 60 V RMS 300 kHz Tolerance of Calibration Source PPM Purpose of Calibration Step Establishes gain and DC offset for the 2 2 mV range Calibrates the relative frequency response of INPUT 1 and INPUT 2 through the 1 kV divider 1 and 1 minute stability better than 50 ppm Calibrates the relative frequency response of INPUT 1 and INPUT 2 through the 1 kV divider 1 and 1 minute stability better than 50 ppm Calibrates the relative frequency response of INPUT 1 and INPUT 2 through the 220 V divider and 1 minute stability better than 50 ppm Calibrates the relative frequency response of INPUT 1 and INPUT 2 through the 220 V divider 1 and 1 minute stability better than 50 ppm Calibrates the relative frequency response of INPUT 1 and INPUT 2 through the protection circuit 1 and 1 m
152. 1002 100 100 160 3 of 4 Figure 7 2 2 Front Panel PCA 7 8 Schematic Diagrams DISPLAY ANODE DRIVERS TP25 TP27 TP26 04242 CDCLK 3 38 4 37 04 36 STRB DRVR 04 40 SD 16 Un 7 18 919 BLANK BLANK BLANK 21 BLANK GLK GLK GLK 25 STRB R STRB STRB 24 STRB SERIAL SERIAL SERIAL SKRIAL IN D OUT b D IN OUT D IN OUT gt N 917 ais 919 920 921 422 423 024 925 926 927 928 029 030 031 916 932 ary Q17 417 818 s 918 O19 019 918 9201620 Q20 16 920 BST L TE 921 921 922 15 25 922 923 Te Bee 025 9 24 923 924 AE 924 12 BE 924 425 Bem Qm Lr NE I AEN 425 9269 pd 226 MES 110 926 927 911 927 L cR ERTI 427 38 5 912 928 5 22 EE SL 3012 Q28 929 913 929 __ 22 1013 029 030 114 0305 55 2189 27 4014 030 615 031 915 631 _ 545 919 28 018 031 916 932 918 432 5 2 L 49 1016 932 ULN5818EP DULN5848EP ULN581BEP ULNS818EP gt ioi or er 2 00 5 I 512 21512 ito fro io ien ioo
153. 2 to turn off LED indicates that the 5 V supply is on and that the CPU is operating i e not reset RESETL also resets the rear panel assembly The other output RESET drives two inverters in U2 One of these inverters provides HALT The other generates which drives the processor s RESET and provides a reset for the front panel interface and DUARTS dual universal asynchronous receiver transmitter circuitry 2 Theory of Operation Digital Section Detailed Circuit Description 9 519 lOHINOO gt x 5420126 185340 en LINDYIO M9019 ZHNZ SZ LINDYIO 1299290 9 200 820 3OV3H3LNI 3OVJH3LNI uvad Zen sen LINDYIO HVON3 IVO 9019 ven een 8LN SEN orn 189089 lOHLNOO sn 300930 8n 55 OYIN 0009H89 lt 185340 400 000 LOV 40 0 SOV LOV 400 000 SOV LOV 200 000 SIV LOV 8L V LOV ZIV LOV 204 004 vOV LOV 04 00 2cV ELV
154. 2 0 3 0 50 50 kHz 100 kHz 10 5 0 8 0 100 kHz 300 kHz 18 15 0 15 0 300 kHz 500 kHz 30 30 0 30 0 500 kHz 1 MHz 90 65 0 65 0 10 Hz 20 Hz 8 1 5 3 0 20 Hz 40 Hz 5 1 5 3 0 40 Hz 20 kHz 5 1 5 3 0 22V 20 kHz 50 kHz 5 2 0 3 0 50 50 kHz 100 kHz 10 5 0 8 0 100 kHz 300 kHz 18 15 0 15 0 300 kHz 500 kHz 30 30 0 30 0 500 kHz 1 MHz 90 65 0 65 0 10 Hz 20 Hz 8 1 5 3 0 20 Hz 40 Hz 5 1 5 3 0 40 Hz 20 kHz 5 1 5 3 0 20 kHz 50 kHz 5 2 0 3 0 50 50 kHz 100 kHz 18 5 0 8 0 100 kHz 300 kHz 36 15 0 15 0 300 kHz 500 kHz 48 40 0 40 0 500 kHz 1 MHz 120 75 0 75 0 1 5790 Service Manual Secondary Performance and Operating Characteristics cont 24 our Temperature Coefficient Voltage Range Frequency Range Pe H lt a of Reading PPM C 10 Hz 20 Hz 8 1 5 3 0 20 Hz 40 Hz 5 1 5 3 0 40 Hz 20 kHz 5 1 5 3 0 220 V 20 kHz 50 kHz 5 2 0 3 0 50 50 kHz 100 kHz 18 5 0 8 0 100 kHz 300 kHz 36 15 0 15 0 300 kHz 500 kHz 48 40 0 40 0 10 Hz 20 Hz 8 1 5 4 0 20Hz 40Hz 5 1 5 4 0 700 V 40 Hz 20 kHz 5 1 5 4 0 500 20 kHz 50 kHz 18 5 0 7 0 50 kHz 100 kHz 36 15 0 15 0 10 Hz 20 Hz 8 1 5 4 0 20 Hz 40 Hz 5 1 5 4 0 1000 V 40 Hz 20 kHz 5 1 5 4 0 500 20 kHz 50 kHz 18 5 0 7 0 50 kHz 100 kHz 36 15 0 15 0 1 Add to uncertainty when mor
155. 2 for a 2 V output Set the 845A range to 10 mV Set 845A OPR ZERO to OPR Reduce the 845A range switch setting until the largest on scale reading is obtained Adjust the 5440B for a null Repeat this procedure until you obtain a null of 1 Set the 845A OPR ZERO to ZERO and set the 5700A to STANDBY Record the 5440B Voltage indication in Table 3 3 after 5440B CHARACTERIZED 2 V OUTPUT Set the 5440B to STANDBY Set the 752A MODE switch to 1 V Set the 5440B output to the characterized 6 V output recorded in Table 3 3 OPERATE Set the 5700A to 0 6 V OPERATE Set the 845A to the 10 mV range Reduce the 845A range switch setting until the largest on scale reading is obtained Adjust the 5700 for a null Repeat this procedure until you obtain a null of 0 1 uV Record the 5700A Error Display indication opposite 0 6 V in Table 3 3 Set the 5700A to STANDBY Press CHNG SIGN on the 5440B Set the 5700A to 0 6 V OPERATE Set the 845A to 10 mV range Repeat the nulling procedure of step 26 recording the 57004 Error Display indication opposite to 0 6 V in Table 3 3 Set the 5700A to STANDBY Set the 5440B output to the characterized 2 V output recorded in Table 3 3 OPERATE Set the 5700A to 0 2 V OPERATE Set the 845A to 10 mV range Repeat the nulling procedure of step 26 recording the 5700A Error Display indication opposite to 0 2 V in Table 3 3 Set the 5700A to STANDBY Press CHNG SIGN on the 5440B
156. 2 mV Negative DC LF 10 Hz Linearity LF 10 Hz Linearity Calibration and Verification Periodic Calibration 3 Table 3 5 Calibration Steps in Periodic Calibration cont 1000 V DC 1000 V DC 600 V DC 600 V DC 200 V DC 200 V DC 60 V DC 60 V DC 600 mV DC 600 mV DC 200 mV DC 200 mV DC 460 mV DC 60 mV DC 420 mV DC 20 mV DC 2 V RMS 10 Hz 600 mV RMS 10 Hz 20 V DC 20 V DC 6 V DC 6 V DC 2 V DC 2 V DC Tolerance Calibration Source PPM 3 3 1000 3 3 3 5 10 35 100 50 90 Purpose of Calibration Step Establishes gain and DC offset for the 1000 V range Establishes gain and DC offset for the 700 V range Establishes gain and DC offset for the 220 V range Establishes gain and DC offset for the 70 V range Establishes gain and DC offset for the 22 V range Establishes gain and DC offset for the 7 V range Establishes gain and DC offset for the 2 2 V range Establishes gain and DC offset for the 700 mV range Establishes gain and DC offset for the 220 mV range Establishes gain and DC offset for the 70 mV range Establishes gain and DC offset for the 22 mV range Establishes gain and DC offset for the 7 mV range Establishes gain and DC offset for the 2 2 mV range Generates a correction for thermal sensor non linearity at low F and f 3 17 5790 1000 100 2
157. 200 8 0 10Hz 20Hz 55 60 1 5 61 1 5 62 1 5 20 Hz 40 Hz 20 27 1 5 29 1 5 34 1 5 40 Hz 20 kHz 15 22 1 5 24 1 5 31 1 5 700 20 2 50 2 15 22 2 0 24 2 0 33 2 0 50 2 100 2 51 2 5 52 2 5 59 2 5 100 kHz 300 kHz 100 4 0 120 4 0 170 4 0 300 2 500 2 260 6 0 270 8 0 310 8 0 500 kHz 1 MHz 890 6 0 950 8 0 1200 8 0 1 8 Introduction and Specifications Specifications Relative Uncertainty Specifications cont 5 of Calibration Temperature Relative Uncertainty Voltage Range Frequency Range gd Dad ares 520 2 Years 90 Days 1 2 Years 10 Hz 20 Hz 55 60 61 62 20 Hz 40 Hz 19 26 28 34 40 Hz 20 kHz 15 20 22 27 22V 20 kHz 50 kHz 15 21 23 33 50 kHz 100 kHz 49 50 57 100 kHz 300 kHz 92 110 160 300 kHz 500 kHz 220 230 280 500 kHz 1 MHz 830 890 1200 10 Hz 20 Hz 55 60 61 62 20Hz 40Hz 19 27 29 36 40 Hz 20 kHz 15 20 22 27 7V 20 kHz 50 kHz 18 23 26 35 50 kHz 100 kHz 62 64 73 100 kHz 300 kHz 140 150 180 300 kHz 500 kHz 360 380 450 500 kHz 1 MHz 1100 1200 1500 10 Hz 20 Hz 55 60 61 62 20Hz 40Hz 19 28 30 37 40 Hz 20 kHz 15 20 22 27 22V 20 kHz 50 kHz 18 23 26 35 50 kHz 100 kHz 62 64 69 100 kHz 300 kHz 140 150 180 300 kHz 500 kHz 360 380 450 500 kHz 1 MHz 1100 1200 1500 10 Hz 20 Hz 55 60 62 63 20Hz 40Hz 19 29 31 39 40 Hz 20 kHz 15 23 25 34 20 50 2 22 25 27 39 50 kH
158. 23 5790 Service Manual 2 24 2 45 2 46 Measurement Display filament driver circuitry centers on transistors Q7 Q12 The transistors are driven by 7406 open collector drivers U13C and U13D These drivers are controlled by AOUT and BOUT as in the Control Display When AOUT is high U13C turns Q8 and 10 10 turns Q12 on providing a path for the filament current through Q8 and Q12 Zener diode VR4 provides the DC voltage offset necessary for proper filament operation Then when BOUT is high U13D turns Q7 and Q9 on Q7 turns Q11 on providing a path for the filament current through Q9 and Q11 effectively reversing the direction of the voltage driving the filament Zener diode VR3 provides the DC voltage offset necessary for proper filament operation Dual port RAM U2 contains all the Measurement Display data written by the 68HC000 microprocessor on the CPU board U5 contains a 7 bit address counter which US uses to read the contents of U2 U2 provides a BUSYO signal to U3 which is active low whenever the CPU and US try to access the same RAM location at the same time If the microprocessor attempts to write to the same RAM location 05 is reading as it refreshes the Control Display U3 uses BUSYO to hold off DTACK to the microprocessor This prevents written data from being lost The other busy signal generated when US attempts to read from a location being written to by the microprocessor is ignored Losing display data for
159. 2E TTT Table C 37 Group DC 22VHF DC Constants High Frequency 22 V Range 5790 Table C 38 Group ZC 22VHF More DC Constants Frequency 22 V Range IA 22VHF Rough gain input to A D ratio Table C 39 Group AC 22VHF Flatness Constants High Frequency 22 V Range Table 40 Group DC_70V Constants 70 V Range DI 70V Basic gain Ref DAC to input ratio OF 70V foo Full scale calibrated DC offset Table C 41 Group ZC_70V More DC Constants 70 V Range Z_70V 00 Zero calibrated offset IA 70V 31 6228 Rough gain input to A D ratio Table C 42 Group AC 70V Flatness Constants 70 V Range ET TT 70 TTE Table C 43 Group DC 220V DC Constants 220 V Range DI 220V Basic gain Ref DAC to input ratio OF 220V foo Full scale calibrated DC offset Appendices Calibration Constant Information Table C 44 Group ZC 220V More DC Constants 220 V Range Z 220V 00 Zero calibrated offset 1 _220 100 0 Rough input to A D ratio Table C 45 Group AC 220V Flatness Constants 220 V Range Dean fees Table 46 Group 700 Constants 700 V Range DI 700V Basic gain Ref DAC to input ratio OF 700V 00 Full scale calibrated DC offset Table C 47 Group ZC 700V More DC Constants 700 V Range Z 700V 00 Zero calibrated DC offset IA 700V 316 228 Rough gain input to A D ratio Table C 4
160. 3 wem Tene Fuss T G TT G L nu RIVET AL 089 344 L SEMI TUBULAR OVAL HEAD AL 089 DIA 344 L SEMI TUBULAR OVAL HEAD 9458 ON 315ID 750OD TO 5 BUMPER RUBBER BLACK 50 BUMPERRUBBERBLACK S0SQ 12 12 THK ADHESIVE 9598 1 7 EJECTOR PWB NYLON 1 PART INSUL GT TRANSISTOR 152207 MOUNT DAP TO 5 118218 218 CONNECTOR DIN41612 TYPE CONNECTORDINATG2 TYPE C M RTANGGAPIN RT ANG 64 PIN 807800 gt ee ME RESISTOR A73R RES CERM 560 5 2W 100PPM 643764 List of Replacable Parts 6 Parts Lists R2 R5 RESISTOR A52R RES CF 20K 5 0 5W 641099 TP1 6 TP8 JUMPER R05R JUMPER WIRE NONINSUL 0 200CTR 816090 10 21 BIPOLAR 7905 VOLT REG FIXED 5 VOLTS 0 5 AMPS 816322 IC VOLTAGE REGULATOR LINEAR LM340L 5V 100MA TO 816355 39 BULK ZENER 1N5268B 844977 A52R ZENER UNCOMP 82 0V 596 1 5MA 0 5W RESISTOR RES CERM SIP 10 PIN 5 RES 10K 2 529990 BAG MYLAR STATIC SHIELD OPEN 680967 TOP 0031 10 00 14 00 4 Static sensitive part BIPOLAR 7918 IC VOLT REG FIXED 18 VOLTS 1 5AMPS 845474 6 63 5790 Y m
161. 5 and the 18 1 supplies Each supply uses a full wave bridge configuration The unregulated 5 supply consists of bridge rectifier CR15 and filter capacitor C19 The input is fused with 1 6 A slow blow fuse F8 The regulated 5 1 supply uses the unregulated 5 supply and contains regulator 02 filter capacitor C20 and protection diode CR16 2 27 5790 Service Manual 2 28 2 55 2 56 The 18 supply consists of bridge rectifier CR17 and filter capacitor C21 Its input is fused with 0 5 A slow blow fuse F9 The regulated 18 FR1 supply uses the unregulated 18 supply and contains regulator U3 filter capacitor C22 and protection diode 18 Unregulated FR1 Supply 15 return path for the unregulated 30 supply This supply uses full wave bridge rectifier CR14 and filter capacitor 18 Its input 15 fused with 0 5 slow blow fuse F7 FR2 Supplies FR2 COM 15 the return path for unregulated 30 FR2R supply and regulated 5 FR2 supply Each supply uses a full wave bridge configuration The unregulated 30 FR2R supply consists of bridge rectifier CR7 and filter capacitor C9 Its input is fused with 0 5 A slow blow fuse F4 The 5 FR2 supply consists of bridge rectifier CR11 filter capacitor C11 regulator U1 bypass capacitor C12 and protection diode CR9 The input 15 fused with 315 mA slow blow fuse F6 2 57 Regulator Guard Crossing Assembly
162. 6 ABI AGR 40 1 0 LZ STRB DRVR AIL AiR 38 DEAT FPAS 14 ATR 1 02 A2L A2R BOAS 32 _ ABL 1795 L3 OP GA DATACLK ASL ASR ASL ASR 104 12 AAL ASR 1 08 11 OCA GRIDCLKO ABL AbR tl BUAS EERO 18 DOL D7R 1 06 STRB DRVRO ARL ABR DIL DSR 1 07 GRIDDATAO ATL A78 29 BOAT UDAZ 2 29 1021 DSR L S DATACLKO ABL 38 DBAS ___ DAR 1 09 55 ABL ASR EFPD 22 04 D3R 20 17050 FRNTPNLCS D5L 022 5359 _ 2111 1 011 PSFAILINTR DOL D7R I o08 PERS DeL DIR 254 1 012 CDCLK DIL DER 1 07 FRO 25 DOR 1 013 OTDBLANK 1 014 DMDBLANK 28 25 021 D5R 11 1 08 27 D3L DAR 1 09 09 18 KEY BOARDIN 1 1 018 460 8KHZ DAL D3R 1 010 16 02429 ENCODERINTR 42 17016 BOUT SCAN 09 3 STROBE 43 17017 DPRENAO AOUT DBL 17 011 18 SCAN 33 DBL BIR 14012 28 7018 34 GRIDDATAQ U15 43 CLOCK BOR 1 013 rove 35 7 D OUT 27 1 014 1 020 36 STRB DEVRO 1 14 24 DOTMATFILAMENTA U18 21 999HZ 41 1 015 1 021 DATACLKO 14 23 919 D QUT CDCLK 42 1 016 CLOCK 2 hcLki 1 022 38 SRZDCLKO jU15 23 DOTMATFILAMENTB 431 17017 38 DPRENA 90 914 43 QUTPUTFILAMENTO 1 018 _54 GRIDDATA 420 43 P OUTPUTFILAMENTA 1 018 PAL IMAGE U49 D QUT 5 020 36 STRB BRYR UTB 24 050 D OUT 1 021 0128 23 z 022 L 38 GRID 920 23 DLK2 _
163. 66 2 67 2 68 2 59 2 70 2 71 Theory of Operation 2 Analog Section Detailed Circuit Description Inguard Memory Configuration The microcontroller U56 has 32 KB of external EPROM program memory in IC U64 IC U62 provides 8 KB of external static CMOS RAM Programmable Logic Device PLD U58 does the decoding of the microcontrollers address and the status lines to select the appropriate device Inguard Clock Circuit Crystal Y52 resistors R54 R53 and R55 capacitors C61 and C62 along with inverters U51A and U51F provide the 7 3728 MHz system clock Programmable Logic Device PLD 058 divides this by two to generate the 3 6864 MHz DUART clock called DUARTCLK Inguard Watchdog Timer The watchdog timer circuit uses a 74 4020 U59 counter The microcontroller U56 generates a 19 2 kHz square wave SCLK on pin 11 Once the clock frequency is initialized it runs without software supervision This clock drives 1 59 which divides 16384 to obtain a logic low interval of 427 ms followed by a logic high interval of 427 ms The output of the U59 goes through inverter 0510 to generate the NMIPOP signal a nonmaskable interrupt to the microcontroller Programmable Logic Device PLD 058 also gets NMIPOP which it uses to generate POP Circuitry on the analog assemblies use the POP signal to open all the input relays and clear other circuitry The microcontroller must toggle pin 11 of U59 more frequently than 427 ms to
164. 68 and C15 are for bypass Capacitor C14 improves ripple rejection Diode CR15 protects the regulator against shorts at the input while CR13 and CR27 protect the regulated output from reverse voltage Regulated 15 CH Supplies CH is the return path for the 15 CH and 15 CH supplies The 15 CH supply uses unregulated 15 CHR supply from the Filter assembly This supply uses three terminal TO 220 regulator U2 Capacitors C1 and C2 are for bypass Diode CR3 protects the regulator against shorts at the input while CR2 protects the regulated output from reverse voltage The 15 CH supply uses unregulated 15 CHR supply from the Filter assembly This supply uses three terminal TO 220 regulator U3 Capacitors C4 and C5 are for bypass Diode protects the regulator against shorts at the input while CR5 protects the regulated output from reverse voltage FR1 Supply COM is the return path for 30 1 supply This supply uses the unregulated 30 FRIR supply from the Filter assembly and consists of three terminal TO 39 regulator U1 with heat sink bypass capacitors C3 and C6 and protection diodes CR4 and CR6 Resistors and R2 set the output voltage Capacitor C7 improves ripple rejection Diodes and CR4 protect U1 against input shorts while CR6 protects against reverse voltage 2 29 5790 Service Manual 2 63 2 64 2 65 2 Supply 2 15 return path
165. 8 7 Press the DO STEP softkey and enter the 1 kHz reference value measured for the APPLIED VALUE 8 Set the 5700A to 3 2 V at 10 Hz and adjust the 5700A to the total error value at 10 Hz that was recorded in Table 3 8 during source characterization 9 Press the ENTER key and the system will calibrate the range at 10 Hz and step to the 100 Hz calibration point 10 Set the 5700A to 100 Hz and adjust the 57004 to the total error value at 100 Hz that was recorded in Table 3 8 during source characterization 11 Press DO STEP and LAST ENTRY keys to enter the current APPLIED VALUE 12 Press the ENTER key and the system will calibrate the range at 100 Hz and step to the 10 kHz calibration point 13 Proceed through the range at each calibration point frequency in the same manner as steps 10 11 and 12 by applying the proper frequency and total error values Note that the total error value is the sum of the errors of the 5700 and all attenuators used for that range and frequency 14 When the calibration program has completed all the steps in the 7 V range it will step to the beginning of the 2 2 V range at 10 Hz 15 Install the 10 dB attenuator as required by Table 3 9 for the 2 2 V range 16 Establish the 1 kHz reference for this range by again setting the 5700A to 3 2 V at 1 kHz and the 5790 to 2 2 V range The 5790A will measure the magnitude Record this value in Table 3 8 3 34 17 18
166. 8 Group AC 700V Flatness Constants 700 V Range ooun Table C 49 Group DC 1000V DC Constants 1000 V Range DI 1000V 0 005 Basic gain Ref DAC to input ratio OF 1000V foo Full scale calibrated DC offset 5790 Table 50 Group 2 1000 Constants 1000 V Range 2 1000 foo Zero calibrated DC offset IA 1000V 1000 0 Rough gain input to A D ratio Table C 51 Group AC 1000V Flatness Constants 1000 V Range rantes Table C 52 Group WDC 2 2MV Gain Constants Wideband 2 2 mV Range DI 2 2MV WB 5000 0 Basic gain Ref DAC to input ratio IA 2 2MV WB 0 0316228 Rough gain input to A D ratio Table C 53 Group 2 2 Flatness Constants Wideband 2 2 mV Range vane emn feum C 10 Appendices Calibration Constant Information Table C 54 Group WDC 7 Gain Constants Wideband 7 mV Range DI 7MV WB 1000 0 Basic gain Ref DAC to input ratio IA 7MV WB Rough gain input to A D ratio Table C 55 Group 7 Flatness Constants Wideband 7 mV Range vane Table C 56 Group WDC 22MV Gain Constants Wideband 22 mV Range DI 22 WB Basic Ref DAC to input ratio IA_22MV_WB Rough gain input to A D ratio 5790 sema Table C 58 Group WDC 70MV Constants Wideband 70 mV Range
167. 86 39 2 13 696 112 25 Jars 232 ULNSB81BEP ULN5818EP ULNS818BEP ULN5818EP 5790A 1002 4 of 4 DISPLAY GRID DRIVERS LAST MODIFIED Mon Nov 18 13 17 43 1991 Figure 7 2 A2 Front Panel cont 5790 5790 1603 Figure 7 3 Analog Motherboard Schematic Diagrams 7 DRAIN ORANGE BARE 5 SHUNT 60 POST DRAIN 2 BLACK 1 5790 3025 INPUT CABLE 6D 552 IN2 HI MECCA 60 POST GD CHASS2 1 2 4 NSTALL gt MOUNTED ON GUARD CHASSIS 06 WIDEBAND 4106 DESIGNATOR IN1 HE LO GD CHASS2 SHUNT GD CHASS2 TRANSFER 2110 52 31A 4 29 XFER LO 28A SHU NT 27 26 25 IN2 24 23A 22 21 29A GD CHASS2 RCL DIV OUT RCL 19 SP19 18A SP18 17 5 17 19A 5216 SP15 14A 5 14 QUT 12A RCL SDi SDL 11A SDL WB CHOP LO we CHOP 10 WB CHOP WB CHOP HI 7 8 1 8 15 14 15 4 VIEW I
168. 90 WASHER WASHER FLAT STL 160 281 010 111005 11 514 522 474 481 SCREW 6 32 1 250 PAN PHILLIPS STEEL ZINC 159756 8 CLEAR LOCK H523 524 WASHER WASHER FLAT STL 191 289 010 111047 2 H525 5790A 8027 SPACER 902924 1 5440A 8198 01 BINDING POST STUD PLATED 102707 1 MP101 102 5790A 8014 GASKET 885715 2 MP104 5790A 4405 4R01 BASE CABLE 893321 1 MP108 5790A 2710 RN SUBSTRATE ASSY 4801 893180 1 MP301 5700A 8039 CALIBRATION CERTIFICATION DECAL 891718 1 MP302 5790A 2502 FRONT PANEL MODIFIED 880737 1 MP303 5700A 8005 LENS SHIELD 760843 1 MP305 5790A 8001 KEYPAD ELASTOMERIC 1623584 1 MP306 GROMMET GROMMET EXTRUDED POLYETHYLENE 085 854351 2 MP504 MP307 5790A 8007 LENS DISPLAY 880752 1 MP308 5790A 8008 NAMEPLATE ELECTROFORM 885657 1 MP309 ADAPTER ADAPTER COAX N F N M 875443 1 MP325 5700A 8072 DECAL POWER ON OFF 886312 1 MP327 5790A 8003 DECAL INPUT 880570 1 MP328 5790A 8002 DECAL KEYPAD 880526 1 MP337 338 5700A 2053 01 HANDLE INSTRUMENT GRAY 7 886333 4 MP531 532 MP401 5700A 8067 SIDE EXTRUSION 886288 2 MP425 MP402 5700A 8066 INSERT EXTRUSION 886283 2 424 404 405 5790A 2501 FAN CONNECTOR ASSEMBLY 885652 2 6 6 List of Replacable Parts Parts Lists MP411 5700A 2046 POWER BUTTON ON OFF 775338 1 MP412 415 5700A 2043 01 BOTTOM FOOT MOLDED GRAY 7 868786 4 MP417 418 FTCL 8001 01 LABEL CALIB C
169. 90A appears damaged or operates abnormally protection may be impaired Do not attempt to operate it When in doubt have the instrument serviced Introduction and Specifications 1 Specifications Do Not Remove the Cover unless Qualified To avoid electric shock do not remove the 5790A cover unless you are qualified to do so Service procedures are for qualified service personnel only Do Not Service Alone Do not perform internal service or adjustment of this product unless a person capable of rendering first aid resuscitation is present Use Care when Servicing with Power On Dangerous voltages exist at several points inside this product To avoid personal injury do not touch exposed connections and components while the power is on 1 15 Specifications Specifications are valid after allowing a warm up period of 30 minutes or twice the time the 5790A has been turned off whichever 15 less For example if the 5790A has been turned off for 5 minutes the warm up period is 10 minutes To simplify the evaluation of how 5790A covers you workload use the Absolute Uncertainty Specification Those include stability temperature coefficient linearity and traceability to external standards Note When you use the 5790A within 15 of the temperature of the last calibration you do not need to add anything to the Absolute Uncertainty Specifications to determine the ratios between 5790 uncertainties and the uncertainties of a unit u
170. A 885608 1 4 A16 DAC PCA 885611 1 4 A17 REGULATOR GUARD CROSSING PCA 874859 1 4 A18 FILTER PCA 885616 1 4 A19 DIGITAL POWER SUPPLY PCA 885624 1 4 A20 CPU PCA 885629 1 4 A21 REAR PANEL PCA 885632 1 4 A22 5700A 4201 TRANSFORMER MODULE ASSY 813527 1 A23 5700A 4210 AC LINE FILTER ASSY 775445 1 A62 5790A 4244 ASSEMBLY INPUT BLOCK 1645207 1 E401 5440A 8197 01 BINDING HEAD PLATED 102889 1 F401 FUSE FUSE 25X1 25 1 5A 250V SLOW 109231 1 F402 403 FUSE FUSE 25X1 25 0 75A 250V SLOW 109256 2 H82 NUT NUT EXT LOCK STL 6 32 152819 1 H83 NUT NUT HEX BR 1 4 28 110619 1 H85 WASHER WASHER LOCK INTRNL STL 2671D 110817 1 H101 104 SCREW 8 32 375 PAN PHILLIPS STEEL ZINC 114124 4 CLEAR LOCK H12 013 SCREW 6 32 375 PAN PHILLIPS STAINLESS 334458 8 H301 STEEL LOCK H482 483 H485 H491 492 H302 SCREW 4 40 625 PAN PHILLIPS STEEL ZINC 145813 1 CLEAR LOCK H305 313 SCREW 5 20 312 WASHER HEAD PHILLIPS STEEL ZINC 494641 9 CHROMATE HI LO THD FORM H314 SCREW SCREW PH P LOCK SS 6 32 625 412841 1 H315 WASHER WASHER FLAT BR 119 281 025 110775 1 H325 328 SCREW SCREW CAP SCKT SS 8 32 375 295105 20 6 6 5 5790 445 456 503 506 H329 331 SCREW SCREW FHU P LOCK MAG 55 6 32 250 320093 26 H440 442 H457 472 H493 496 H414 420 SCREW SCREW PH P LOCK SS 6 32 750 376822 16 H484 H501 502 H507 510 H15 16 H473 H4
171. A17 2 58 Regulator Guard Crossing assembly A17 provides two separate functions voltage regulation for the analog power supplies and digital controller functions for the inguard The voltage regulation portion is described first followed by the digital control portion Refer to the schematic diagrams for the Regulator Guard Crossing assembly for this discussion Voltage Regulator Circuitry The Regulator Circuit receives unregulated DC from the regulator filter circuit on the Filter assembly A18 and provides nine regulated DC outputs that power the analog assemblies Table 2 10 lists the regulated supplies from the Regulator Guard Crossing Assembly Table 2 10 Regulated Outputs from the Regulator Guard Crossing Assembly Nominal Current 15 CH 15V 800 mV 200 mA TP5 common TP4 15 CH 800 mV 2 200 mA common TP4 5RLH 5 975 V 425 mV 600 mA TP14 common TP10 og 2 60 2 61 2 02 Theory of Operation 2 Analog Section Detailed Description Regulated LH Supplies The 5 RLH supply used the unregulated 5 LHR supply from the Filter assembly The 5 RLH supply uses three terminal TO 3 regulator U11 bypass capacitors C20 and C70 protection diodes CR17 and CR20 Resistors R21 and R22 set the output voltage level of 5 RLH LH COM is the return path The 5 LH supply used the unregulated 5 LHR supply from the Filter assembly The 5 LH supply uses three terminal TO 3 re
172. A3 These two Motherboards are mechanically fastened together with screws They electrically connected by connectors 81 82 on the Digital Motherboard and connectors J81 and J82 on the Analog Motherboard AC voltage taps from the Transformer assembly A22 are connected to the Analog Motherboard through these connectors Refer to the Motherboard and Input Block schematic diagrams for more information Digital Motherboard Assembly A4 The Digital Motherboard contains the line select switches line fuse power switch a fiber optic transmitter J73 and a fiber optic receiver J74 It also contains connectors for the Transformer assembly A22 Digital Power Supply assembly A19 CPU assembly A20 Front Panel assembly A2 Rear Panel assembly A21 and the two 24 V DC fans mounted in the chassis The fiber optic receiver and transmitter provide the serial communication link between the CPU on the unguarded Digital Motherboard and the Regulator Guard Crossing on the guarded Analog Motherboard Transformer Assembly A22 The Transformer assembly receives AC line inputs routed through the A4 Digital Motherboard This assembly supplies outputs throughout the 5790A all of which are routed through the A4 Digital Motherboard The Transformer assembly the Filter assembly A18 and the regulator portion of the Regulator Guard Crossing assembly A17 create the system power supply for all analog assemblies The Transforme
173. ADG201HS 15V 75 875328 OHMS SPST QUAD DIP16 TUBES CMOS 74HCT374 IC CMOS OCTL D F F W 3 STATE EDG 585364 TRG BIPOLAR 339 IC COMPARATOR QUAD 14 PIN DIP 387233 BIMOS 5801 IC BIMOS 8 CHNL HI VOLT W LATCH 782912 2 CMOS 74HC00 IC CMOS QUAD 2 INPUT NAND 707323 ZENER UNCOMP 1N4730A 3 9V 5 64MA 1W DO 41 BULK 535641 ZENER UNCOMP 1N5256B 30V 5 4 2MA 500MW DO 634121 1 35 TAPE 5790A 2703 RN SUPPORT ASSY 4R03H 885512 5790A 2704 RN SUPPORT ASSY 4R04H 885517 5790A 2705 RN SUPPORT ASSY 4R05H 885520 Z5 Z9 10 RESISTOR RES CERM SIP 8 PIN 4 RES 10K 2 513309 RESISTOR RES CERM SIP 8 PIN 7 RES 10K 2 412924 RESISTOR NETWORK CERMET ISOLATED 8 4 714345 1 RES 1K 2 0 2W 100PPM SIP8 BULK 4 Static sensitive part a N 6 Parts Lists List of Replacable Parts A96 R21
174. Assembly A15 sse Chopper Circuit A D Amplifier Circuits Digital Control and Power Supply DAC Assembly A16 DAC Assembly Reference Circuitry Duty Cycle Control Circulit DAC Filter Circuit DAC Output Stage Sense Current Cancellation Circuit esses Linearity Control Circuit a Negative Offset Circuit eset eerie tide ree Wideband Module Option 03 Input Signal Path for the Upper Four Ranges Input Signal Path for the Lower Four Ranges DC Offset Feedback for Amplifier U3 Lower Ranges RMS Sensor Circuit Transfer Methodology 2 111 2 112 2 113 2 114 2 115 Offset Feedback for RMS Sensor Amplifier Range Comparator Wideband Frequency Counter Digital Control A6A2 Input Protection Module Theory of Operation Introduction 2 2 3 5790 2 4 2 1 2 2 2 3 Theory of Operation 2 Introduction Introduction This chapter provides theory of operation in increasing level of detail The 5790A 15 first defined in terms of how it makes internal A
175. B CHOP 4448 SHT 3 _ 29 FET1 ues 2 L AAA r 100 SHT 3 18k 144448 X 144448 iN4448 ucc G GNDMG 5LH VEE G 60 R148 e U24 13 gt 123 1 SHTI U24 14 SHT3 gt 210 18K V cs4 WB CHOP GND V SAL 4 BAE 45 1088 SIGNAL i U438 Q3 8 10 VVV 51 5 56544 e MPSES44 Q19 22 100 709518 4 zm L C188 22 254 7 18 R83 SHT 5 NOTES UNLESS OTHERWISE SPECIFIED 1 ALL RESISTORS ARE IN ALL CAPACITOR VALUES ARE IN MICROFARADS OHM 1 6 8 10 Figure 7 5 Wideband PCA Option 03 cont 5790 1006 1 of 4 Schematic Diagrams 7 C101 1 2 11 C118 6 8718Y 5 D 05 Q15 SHT 1 51 H NN 26 gt 7
176. BES CMOS 40478 IC CMOS MONOSTABLIASTABL MULTIVIBRATR 4047B C CMOS MONOSTABL ASTABL MULTIVIBRATR 535575 1 Eae VR2 3 ZENER UNCOMP 1N749A 4 3V 5 20MA DO 35 TAPE VR7 ZENER UNCOMP 1N965B 15V 5 8 5MA 400MW DO 35 TAPE sermonmeum Y1 CRYSTAL CRYSTAL 3 84MHZ 0 05 HC 18 U 1 a sas _ List of Replacable Parts 6 Parts Lists Bp mE ozy Bi B Cm in 209 o 5 Ep 910 iral Q Lo Io ro lt 5790 1615 Figure 6 14 A15 A D Amplifier 6 51 5790 6 52 Table 6 16 16 DAC PCA D xp PCA DAC FILTER SIP BURN IN 893276 CAPACITOR CAP POLYPR 0 33UF 5 50V HERMETIC Sep CAPACITOR ROSA CAP AL 10UF 20 63V SOLV PROOF sa 2 ess C27 CAPACITOR ROSR CAP CER 15PF 20 50V COG 820423 2 n sss a C44 C60 CAPACITOR CERAMIC 1000PF 10 50V C0G 1206 TAPE 816843 52 103 CAPACITOR SMR CAP CER 33PF 10 50V COG 1206 747378 1 C57 CAPACITOR ROSR CAP CER 22PF 5 50V COG 747519 C110 111 CAPACITOR FILM POLYESTER 0 22UF V 596 50V 5MM 769257 LS RADIAL TAPE CR1 CR4 5 DIODE SI 1N4448 75V 150MA 4NS RADIAL LEAD PREP DO 740522 35 TAPE _
177. C DC transfers to measure unknown AC voltages Detailed circuit descriptions follow first for system interconnections including the motherboards then for digital assemblies and finally for the analog assemblies The chapter ends with a discussion of how the 5790A uses calibration constants Most of this chapter is devoted to detailed circuit descriptions first in the digital unguarded section then in the analog guarded section 5790A Overview The 5790A AC Measurement Standard is configured internally as an automated AC DC transfer standard All measurements are controlled by internal microprocessors The following elements are among those critical to establishing the accuracy of the 5790A The FTS Fluke RMS Thermal Sensor is the transfer element It compares a precisely known adjustable DC voltage or a square wave derived from DC to an unknown AC voltage If the FTS output remains unchanged when the input switches from the unknown AC voltage to the known DC voltage the RMS value of the AC voltage is equal to the DC voltage The FTS has extremely flat frequency response and has short term stability approaching 1 part per million ppm Highly stable thin film resistor networks scale 7 V range and higher to the FTS 2 V operating level and to scale the precision chopped reference to the 0 7 mV level e ADC analog to digital converter measures FTS output A high resolution DAC digital to analog converter
178. C to input ratio OF 2 2V foo Full scale calibrated DC offset Table C 26 Group ZC_2_2V More DC Constants mV Range Z 2 2M foo Zero calibrated DC offset lA 2 2V Rough gain input to A D ratio Table C 27 Group AC 2 2V Flatness Constants mV Range EY TT RAN Table C 28 Group DC 7V DC Constants 7 V Range DI 7V Basic gain Ref DAC to input ratio OF 7V foo Full scale calibrated DC offset Table C 29 Group ZC 7V More DC Constants 7 V Range z jo Zero calibrated DC offset IA 7 3 16228 Rough gain input to A D ratio Table C 30 Group AC 7V Flatness Constants 7 V Range 20 TIT Appendices Calibration Constant Information Table C 31 Group DC 7VHF DC Constants High Frequency 7 V Range DI 7VHF Basic gain Ref DAC to input ratio Table C 32 Group ZC 7VHF More DC Constants High Frequency 7 V Range IA 7VHF 3 16228 Rough gain input to A D ratio Table C 33 Group AC 7VHF Flatness Constants High Frequency 7 V Range Funston Table C 34 Group DC 22V DC Constants 22 V Range DI 22V Basic gain Ref DAC to input ratio OF 22V foo Full scale calibrated DC offset Table C 35 Group ZC 22V More DC Constants 22 V Range 2 22M foo Zero calibrated DC offset 1 _22 Rough input to A D ratio Table C 36 Group AC 22V Flatness Constants 22 V Range 22 20
179. CAPACITOR SMR CAP CER 270PF 10 50V C0G 1206 837385 CAPACITOR SMR CAP TA 4 7UF 2096 10V 3528 867262 CAPACITOR FILM POLYESTER 0 47UF 10 50V 5MM 913736 PCM RADIAL BULK CR1 2 CR5 2 CR5 DIODE SI PN BAV99 70V 215MA 6NS DUAL SERIES SOT 23 TAPE 742320 CRD I REG DIODE 2MA 1096 SEL TO 226AC 284927 CURRENT REGULATOR DIODE J511 5 3MA 21 3 1 50V 2 852116 LEAD TO 92 TAPE STANDOFF ROUND 6 32 325 HEIGHT 250 296137 OD BRASS SWAGE 062 PANEL THK P1 2 P21 22 2 P21 22 HEADER HEADER 2 ROW 100CTRRTANG6PIN 2 ROW 100CTR RT ANG 6 PIN 912217 ERES L E JFET DUAL ST441SMR TRANSISTOR SI N JFET DUAL SO8 876425 02 3 08 9 TRANSISTOR SI PNP MMBT3906 40V 200MA 250MHZ 225MW SOT 742684 Q13 16 23 TAPE NPN MMBT3904 SMR TRANSISTOR SI NPN 60V 350MW SOT 23 742676 Q7 Q10 JFET SI N SST4416 30V 5MA 500OHMS SELECTED RDS ON SOT 844584 23 TAPE RESISTOR SMR RES CERM 180 5 125W 200PPM 1206 746321 19 RESISTOR SMR RES CERM 1M 5 125W 200PPM 1206 746826 R10 11 RESISTOR CERMET 432 1 0 25W 100PPM 1206 TAPE 811885 RESISTOR SMR RES CERM 1K 5 125W 200PPM 1206 745992 RESISTOR SMR RES CERM 1 5K 5 125W 200PPM 1206 746438 RESISTOR SMR RES CERM 390 5 125W 200PPM 1206 740498 RESISTOR SMR RES CERM 6 2K 5 125W 200PPM 1206 746016 RESISTOR SMR RES CERM 12 5 125W 200PPM 1206 845458 R4 R8 RESISTOR SMR RES CERM 10K 5 125W 200PPM 1206 746610 RESISTOR SMR RES CERM 18K 5 125
180. D n 1048 WIDEBAND output U INPUT SEE TABLE 3 9 FOR ATTENUATORS REQUIRED FOR EACH RANGE elu039 eps Figure 3 13 WIDEBAND Input Flatness Calibration Test Setup The 5700A will be set to a nominal 3 2 V for all flatness calibration The only deviation from the nominal value will be for calibration corrections for the 5700A and the attenuators Enter a range voltage at the top of each copy you made of Table 3 8 7 V 2 2 V 700 mV 220 mV 70 mV 22 mV 7 mV and 2 2 mV Also enter the attenuator corrections as required for each range Add the total error for each frequency and enter the result in the TOTAL ERROR column in each copy The total error equals the sum of errors of the 5700A and all attenuators used for that frequency 3 33 5790 Table 3 9 shows combination of attenuators required to scale input signal properly for each range Table 3 9 Attenuators Required for Each Range 4 Allranges are calibrated in the similar manner The calibration program will prompt you at each step as to what frequency to apply 5 The flatness calibration program starts with the 7 V range at a frequency of 10 Hz 6 To establish a 1 kHz reference at the beginning of each range set the 5700A to 3 2 V and 1 kHz and set the 5790 to the 7 V range in this case The 5790 will measure the magnitude Record this value in Table 3
181. D 5 96 912 17356 3 105 B 0 4UF R4 4 FROM SCOM SHT 1 5790 1010 THERMAL SENSOR CIRCUIT 3 of 4 Figure 7 8 A10 Transfer PCA cont 7 27 5790 MBD 5 0 LF Sw lt 3 0 gt QUT SW 3 CHOP 03 3 Dc 2 KV 1 SHUNT 0 ZEROCAL 3 MEAS 2 COUNT 1 SLOWNFASTO BLYixOo RLY2x 1 RLY3 2 RLY4x 3 RLY7X 4 HoR a w fa o OUT OUT Tad DISABLEx 4 p OUT cE 812 10 008 our 26 8 A81 7 91 8 20045801 0 1008 tpe CR14 C 7mv i RLY V 1000PF P 94 6 1 2 TR naiai itt PBO 6 SW 3 0 042 20 ALY7x 4 11A 19 ALYax 5 106 __ 2 QUT His 10 3 3 se pas QUT Hz OUTS CR47 45 TPB 09915 14 1N4448 1 4448 13 6 120 PC6 OUT UCNS80 1 CLR 2 m 921 3 020 16 OE 420 15 22 12 420 14 ALHCOM 17V 420 13 5 6 R38 R38 AAA E 12 TEMPx 200 4 7K 15 us 8 Fis D 96 VNO104 OVLD G U4 6 0127 15 PROT IN 200 CR31 D 6 4 6 484448 d 01 2 91 7 C22 SEL lt 3
182. D INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL INDIRECT INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES INCLUDING LOSS OF DATA ARISING FROM ANY CAUSE OR THEORY Since some countries or states do not allow limitation of the term of an implied warranty or exclusion or limitation of incidental or consequential damages the limitations and exclusions of this warranty may not apply to every buyer If any provision of this Warranty is held invalid or unenforceable by a court or other decision maker of competent jurisdiction such holding will not affect the validity or enforceability of any other provision Fluke Corporation Fluke Europe B V P O Box 9090 P O Box 1186 Everett WA 98206 9090 5602 BD Eindhoven U S A The Netherlands 11 99 To register your product online visit register fluke com 1 Introduction and Specifications Title Table of Contents l l JnttodUctiob oce eere eto ee ehem Hei nre 1 2 Service Information A aa l3 ase 1 4 Safety InStructions eere rit Hence PE SS a Su amas S Sus u s 1 5 Input Source s 1 6 Power SOUECE a u 1 7 1 8 Grounding of the 5790
183. D Amplifier PCA cont 7 33 5790 ueG e7 SHT 3 U26 28 SHT 3 326 29 SHT 3 028 30 SHT 3 t TP12 U24 29 DEL U26 31 SHT 3 P115 104 120 SHT 2 U26 32 SHT 3 07 534 024 30 SHT 026 33 SHT 3 426 34 SHT 3 4 ua4 ai sur gj 0260 U26 8 SHT 3 AD DAC U26 9 SHT 3 U24 28 SHT 2 s S e U19 3 SHT 2 R35 SHT 3 DC SNS LO REFERENCE 124 32 SHT 2 i GENERATOR U24 3 SHT 2 T 020 8 BHT 2 016 1 SHT 2 NULLDAC 05 7 SAT 4 I 174043 124 34 SHT 2 i jr 1V REF 1 024254 SHT 2 124 35 SHT 2 05 3 6 11 SHT 1 TAE DUT DC SNS LO C41 66 65 54 B3 52 B1 4700PfF 48006 ARS 4 9 8 gt 3 uz ACTIVE MERCURY 1 End 33 amp 1 SHT 3 R28 amp SUL 4 U13 10 SHT 4 amp E 8 R41 147K 58 1K DC SNS LO ve ovs 5 POLE FILTER A D HI DC SNS LO N 5 El 1 1 1 1 1 1 AD 3 015 3 5 11 14 SHT2 2 SNS 10 SNS LO 17 8 25 7 PHASE SEND Fe Ee DC SNS LO INSTRUMENTATION AMP 412 AD DAC AD4 RCL
184. DER 1 ROW 156CTR 3 380022 FIBER OPTIC FIBER OPTIC RECEIVER 1MBD 822148 FIBER OPTIC FIBER OPTIC TRANSMITTER 1MBD 822155 7 J106 J110 CONNECTOR DIN41612 TYPE C F VERTICAL 64 POS 807818 14 J113 J115 118 J206 J210 J213 J215 218 J811 812 SOCKET SOCKET 1 ROW PWB 156CTR 10 POS 851183 J821 822 wa 4 RELAYRELAYARMATUREZFORM CAS VSEALED RELAY 2 FORM 4 5 V SEALED 875638 T RELAY ARMATURE 2 FORM C 5VDC 876854 _ ee e 28 AL 089 DIA 250 L SEMI TUBULAR OVAL 838482 HEAD DEEP HOLE RR RESISTOR A52R RES CF 750 RESISTOR AS2R RES CF 750 5 0 25W 0 25W 441659 ERIS E RESISTOR A52R RES CF 91 5 0 25W 441683 Pu x RESISTOR A52R RES CF 16K RESISTOR A52R RES CF 16K 5 0 25W 0 25W 442376 _____ 82C55A IC CMOS PROGRMBL PERIPHERAL 780650 INTERFACE 2 ZENER UNCOMP 1N5349B 12V ZENER UNCOMP 1N5349B 12V 5 100MA 5W AXIAL BULK 100MA SW AXIAL BULK 876862 SOCKET SOCKET IC 40 PIN 429282 RESISTOR RES CERM SIP 10 9 RES 3K 2 501528 RESISTOR RES CERM SIP 6 PIN 5 RES 10K 2 500876 1 Static sensitive part List of Replacable Parts 6 Parts Lists
185. DO 186163 35 TAPE m RESISTOR A52R RES CF 2K 5 0 25W 441469 em List of Replacable Parts 6 Parts Lists ZENER UNCOMP 1N975B 39V 5 3 2MA 400MW DO 831248 35 TAPE VR14 15 ZENER UNCOMP 1N967B 18V 5 7MA 400MW DO 327973 35 TAPE Noes Static sensitive part 6 67 5790 Qe LI co 2L Eg H o 5790A 1619 Figure 6 19 A19 Digital Power Supply PCA 6 68 List of Replacable Parts 6 Parts Lists Table 6 21 A20 CPU PCA Part Res Des Description t ss BATTERY PRIMARY LITHIUM 821439 MNO2 3 0V 0 560AH CR2450 COIN PC PINS 24X5MM BULK CAPACITOR SMR CAP TA 220UF CAPACITOR SMR CAP TA 220UF 20 10V 7343H 10V 7343H 106021 ER _ UCET _ SMR CAP CER 0 1UF 10 50V X7R 0805 690500 C14 16 C18 C101 111 C113 C115 C116 C119 120 C125 133 C142 143 C152 oo s C8 11 CAPACITOR SMR CAP CER 22PF 1 50V C0G 0805 sezes 12 13 80 CAPACITOR SMR CAP CER 0 22UF 10 25V X7R 1206 106625 3 EH C81 CAPACITOR SMR CAP CER 330PF 5 50V C0G 0805 512038 1 ze wee EHH Raa 23 Lampu u ms C ese L80 81 INDUCTOR 10UH 10 15MADC 1 15OHM SHIELDED 0805 TAPE 105965 2 Fr su
186. ER OPTIC FIBER OPTIC RECEIVER 1MBD 822148 CONNECTOR CONN DIN41612 TYPE C RT ANG 64 853437 J119 120 CONNECTOR DIN41612 TYPE C F VERTICAL 64 POS 807818 J220 J121 HEADER HEADER 2 ROW 100CTR 34 PIN 851696 HOLDER PART HLDR PART FUSE BODY PWB MT 602763 MP2 HOLDER PART HLDR PART FUSE CAP 1 4X1 1 4 460238 MP2 MP3 10 RIVET AL 089 DIA 250 L SEMI TUBULAR OVAL 838482 HEAD DEEP HOLE MP17 18 SPACER SPACER SWAGED 312 RND BR 1771D 093 837864 MP20 List of Replacable Parts 6 Parts Lists 5 RESISTOR CARBON FILM 68 5 0 25W 350 414532 1 450PPM AXIAL TAPE RV2 VARISTOR VARISTOR 430V 10 1 0MA 519355 we meesemm 6 25 5790 je j 3 20 99 DELTA Y ONLY N S MP22 FS 5790A 1604 Figure 6 6 A4 Digital Motherboard PCA 6 26 List of Replacable Parts 6 Parts Lists Table 6 8 A6 Wideband PCA Option 03 T e WB INPUT PROTECTION PCA 893271 C1 3 C5 8 C110 CAPACITOR R05R CAP TA 6 8UF 20 10V 655043 C4 C111 C113 CAPACITOR R05R CAP TA 22UF
187. ERTIFICATION SEAL 802306 4 MP505 MP539 MP420 5700A 8021 FILTER AIR 813493 1 MP422 423 5700A 8036 DECAL CAUTION 240V 760926 2 MP454 455 6070A 2063 AIDE PCB PULL 541730 2 MP504 5790A 4021 SUB ASSY REAR PANEL 885582 1 MP511 512 CONNECTOR ACCESSORY MICRO RIBBON SCREW 854737 2 LOCK M3 5 6 32 STEEL BLACK ZINC MP513 514 CONNECTOR ACCESSORY D SUB JACK SCREW 4 1777348 2 40 250 LI W FLAT WASHER MP540 LABEL LABEL VINYL 1 500 312 844712 1 MP543 544 WASHER WASHER FLAT SS 119 187 010 853296 2 MP545 M00 800 429 01 DECAL CSA 864470 1 MP656 CE MARK LABEL BLK LABEL CE MARK BLACK 600707 1 P21 22 HEADER HEADER 2 ROW 100CTR RT ANG 6 PIN 912217 8 TM1 5790A SERVICE MANUAL 893292 1 TM2 5790A OPERATOR MANUAL 893284 1 TM3 PROGRAMMERS GUIDE 893375 1 W203 LINE CORD NORTH AM 10 5 15 1 284174 1 5700A 4403 CABLE KEYBOARD REAR PANEL 802710 1 5700A 4404 CABLE REAR PANEL CPU 802728 1 5700A 4408 CABLE FIBER OPTIC 802710 1 Notes 4 Static sensitive part 6 6 7 Service Manual 5790A 9 40 1 SLL 0649 JINGOW LNOYS divi3g 33 48 43H10N vOSd 8 90 zov ar 01 11130 2 2 48 83 10 1 11910 201 OL 90S 0SH 333 AW1dSI0 858 1554 338 aspa shi 196 12 Figure 6 1 Assembly 6 8
188. ES1303 0 51305 17 1 UES1303 MICROFARADS 90A 7618 5 F8 1 6ASLO 5 FR1 AC1 a x U 18 72 4 3 5 FR1 02 78LO5ACG 5 1 AC2 CR17 F9 0 5 510 18 FRIT 1 2 1 18 FR 2 5790 1018 10 18 7 16 18 7 45 5790 4 0 5ASLO 30 FR2 28 30 FR2R 30 82 2 T retta A25 315MSLO 5 FR2 1 26 FR2 12 1N4007 2UF sv 26 79L05ACB 5 FR2 AC2 SND IN 15 5 2 P118 Ls pi 5 LH ACT UES1303 CR2 UES1303 5 LH UEST303 CRS 1 K 5 LH 2 UES1303 P118 1 29 15 ACI 1 6ASLO 2A 529 15 64 50 2 A30 15 CH AC2 1 6 510 5790 1018 2 of 2 Figure 7 16 A18 Filter PCA cont 7 46 Schematic Diagrams 7 E B rd E 5790A 1619 Figure 7 17 A19 Digital Power Supply PCA 7 47 5790 CR1 1N4935 1N4935 75UNREG pas A23 75 CR4 522 184935 1849835 75 2 1N4007 35 1
189. FLUKE 5790A AC Measurement Standard Service Manual PN 893292 January 1992 Rev 5 1 07 1992 2007 Fluke Corporation All rights reserved Printed in USA All product names are trademarks of their respective companies LIMITED WARRANTY AND LIMITATION OF LIABILITY Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service The warranty period is one year and begins on the date of shipment Parts product repairs and services are warranted for 90 days This warranty extends only to the original buyer or end user customer of a Fluke authorized reseller and does not apply to fuses disposable batteries or to any product which in Fluke s opinion has been misused altered neglected contaminated or damaged by accident or abnormal conditions of operation or handling Fluke warrants that software will operate substantially in accordance with its functional specifications for 90 days and that it has been properly recorded on non defective media Fluke does not warrant that software will be error free or operate without interruption Fluke authorized resellers shall extend this warranty on new and unused products to end user customers only but have no authority to extend a greater or different warranty on behalf of Fluke Warranty support is available only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price Fluke reserves the
190. Hz 0 7 0 6 50 kHz Em 7 EN 6 5 kHz Bo No 300 kHz kHz 167 187 No spec spec CCC a or os rmx wo m m Teas e s 20 mm m m m o rer fea e mw Je e _ 22 20 rom Ja e e wm jm Ja e wwe m Ja e e mew m Ja gt e me e e Je e 20 owe m _ Dess eo m rs 20 m m _ ee 20 nes ws e Jo Drm e me m m m _ mm e m J e e mm Ja e wm Ja re ro e wwe wo Ja re ro e mac wo Ja Ja ro e om e Je te ee ro es m __ res ro es mom w wm wo Teas m o m e _ rer zo es rue us me umm ree m ms mm m m _ mis m mw e Jo ls _ Calibration and Verification 3 Verification Table 3 13 Test Record for Main Input Verification cont 5790A Range 9 gt N 90 Day Absolute AC Error Error Spec ppm Measured AC DC Error lt Step Absolute AC Error Measured Absolute gt x amp gt gt Voltage V Frequency AC Source 91 22 200 0 1 DM 92 22 20 0 10 kHz 15 93 22 EN 0 Eros kHz 94 22 200 0 50 kHz kHz ii ws me wowe u o
191. If you need to completely detach the Front Panel from the 5790A you can remove the paddle board from the Analog Motherboard or you can disconnect the input cables from the Front Panel assembly Fluke 5790A elu052 eps Figure 4 4 Front Panel Removal 4 12 Display Assembly Removal and Installation Once the Front Panel has been removed use the following procedure to access the Display assembly 1 Remove the ribbon cable connecting the Display assembly to the Motherboard 2 Remove the six screws securing the Front Panel Display assembly cover shield Three of these screws are accessed from the inside and the other three are accessed along the top of the front panel 3 Remove the seven screws securing the Front Panel Display assembly to the Front Panel Gently lift the Front Panel Display assembly up and remove the keyboard ribbon cable Now remove the Front Panel Display assembly 4 13 Keyboard Assembly Removal and Installation The following procedure assumes that the Display Assembly Removal procedure has already been completed l Remove all output cable connections including GROUND to metal from the front panel binding posts Save all removed hardware Remove the two hex screws at the front of each handle Then remove the front handles Gently release the eight plastic hook catche
192. M 270 5 125W 200PPM 1206 R51 RESISTOR SMR RES CERM 150 1 125W 100PPM 1206 R53 R71 RESISTOR SMR RES CERM 5 1K 5 125W 200PPM 1206 CE pene e 6 53 5790 1 8 JUMPER R05R JUMPER WIRE NONINSUL 0 200CTR 816728 1 TP12 BIFET LF412A IC OP AMP DUAL LO OFFST VOLT LO DRIFT 876367 U BIPOLAR LT1013C IC OP AMP DUAL PRECISION 8 PIN DIP 659516 3 U5 U38 LF356N IC OP INPUT 8 PIN DIP 797720 U6 CMOS 82C54 SMR IC CMOS PROGRMBL INTERVAL 459974 TIMER PLCC U7 OSCILLATOR TTL CLOCK 8MHZ 5V 1000PPM 10 TTL 745984 LOAD DIP4 14 TUBE CMOS 74HC240 SMR IC CMOS OCTL INV LINE DRVR SOIC 783290 BIPOLAR 522 IC COMPARATOR HI SPEED 14 PIN DIP 783704 FAST SOIC TRANSISTOR DUAL ISOLATOR HCPL 2400 ISOLATOR 20 MHZ OPTOCOUPLER 642477 U14 CMOS 74HC74 SMR IC CMOS DUAL D F F EDG TRG SOIC 782995 VR2 VR8 ZENER UNCOMP MMBZ5240B 10V 5 20MA 225MW SOT 642485 VR10 12 23 TAPE VR3 ZENER UNCOMP MMBZ5246B 16V 5 7 8MA 225MW SOT 783720 23 TAPE VR4 ZENER UNCOMP MMBZ5248B 18V 5 7MA 225MW SOT 647115 23 TAPE VRS ZENER UNCOMP 1N746A 3 3V 5 20MA 400MW RADIAL 885496 LEAD PREP DO 35 TAPE VR7 ZENER UNCOMP MMBZ5251B 22V 5 5 6MA 225MW SOT 831230 23 TAPE VR13 ZENER UNCOMP MMBZ5243B 13V 5 9 5MA 225MW SOT 832147 23 TAPE 5700A 4R30T N RNET MF POLY SIP 5700 LO DIVIDER 893334 1 RESISTOR RES CERM SIP 6 PIN 5 RES 510 2 472779 2 Notes 1 Static sensitive part
193. Menu Assuming that the CALIBRATION MODE switch is in the PERIODIC position the Cal softkey produces the following menu Prev Main WBND 2 2V 2 2V Cal Cal Cal Range Range Menu Cal Cal The functions of the softkeys in this menu are elu015 eps e Cal starts DC and AC calibration of the main input The procedure is described under Calibrating the Main Input in this chapter This softkey is Service Cal if the CALIBRATION MODE switch is in the SERVICE position WBND Cal appears only if the Wideband AC option is installed It starts absolute gain and flatness calibration of the Wideband option The procedure is described under Calibrating the Wideband AC Option in this chapter 2 2 V Range AC Cal provides quick access to the main input AC calibration steps of a single range The procedure is the same as for Calibrating the Main Input in this chapter The range showing depends on the range that is presently selected 2 2 Range DC Cal provides quick access to the main input DC calibration steps of a single range The procedure is the same as for Calibrating the Main Input in this chapter The range showing depends on the range that is presently selected 3 5 5790 Service Manual 3 6 Note If the CALIBRATION MODE switch is the SERVICE position sofikey for Xfer Offset Adjust appears in the top level calibration menu It genera
194. NSTALLED GD CHASS2 CHOP LO 104 CHOP 9 XF CHOP LO XF CHOP HI 8A SPR 7A SP7 LAA 2 1 32 31A 17 S 30 17 5 29A 44 8 28 44 5 27 8 RLH 26 5 LH 254 RLH COM 24 LH 23 5 RLH 22 5 LH 21 18 S 204 415 S 19A RLY2 18A RLY4 17 RLYB 16A 15 14 PAS 124 12 5790 1003 1 of 3 Figure 7 3 A3 Analog Motherboard PCA cont 7 11 5790 4 32A 30 XFER LO 29A XFER LO SHUNT 28A SHUNT 274 28A 25A 244 25 224 21 204 19 5 18 __5918 17A SPA 164 SP16 5 15 144 14 13A DIV OUT 12 RCL Tik SDE 104 324 S COM 27A 8 26A 8 LH 25A RLH COM 24A iH COM 57904 1003 2 of 3 Figure 7 3 A3 Analog Motherboard PCA cont 7 12 Schematic Diagrams 7 15 A17 GUARD XING REGULATOR GD CHASS3 J115 4117 32C 32A 32C sia 5 5 32 5 31 31c 31A CH COM BIA CH 30 50A 15 15 CHR 29 294 290 294 15
195. OPERATE Set the 845A to the 10 mV range Repeat the nulling procedure of step 9 recording the 5700A Error Display indication opposite 600 V in Table 3 2 Set the 5700A to STANDBY Set the 720A dials to 0 2000000 Set the 5700A to 200 V OPERATE Set the 845A to the 10 mV range Repeat the nulling procedure of step 9 recording the 5700A Error Display indication opposite 200 V in Table 3 2 Set the 5700A to STANDBY Calibration and Verification 3 Periodic Calibration 12 Press CHNG SIGN on the 5440B Set the 845A to the 10 mV range Set the 5700A to 200 V OPERATE Repeat the nulling procedure of step 9 recording the 5700A Error Display indication opposite 200 V in Table 3 2 Set the 5700A to STANDBY 13 Set the 720A dials to 0 6000000 Set the 57004 to 600 V OPERATE Set the 845A to the 10 mV range Repeat the nulling procedure of step 9 recording the 57004 Error Display indication opposite 600 V in Table 3 2 Set the 5700A to STANDBY 14 Set the 720A dials to 1 0000000 Set the 5700A to 1000 V OPERATE Set the 845A to the 10 mV range Repeat the nulling procedure of step 9 recording the 57004 Error Display indication opposite 1000 V in Table 3 2 Set the 5700A to STANDBY 15 Set the 752A MODE switch to 100 V 16 Repeat steps 10 through 14 for 5700A outputs of 60 20 20 and 60 V DC entering the Error
196. OSSING PCA A16 DAC PCA 4 D A15 A D AMPLIFIER PCA A22 POWER TRANSFORMER A10 TRANSFER PCA A19 DIGITAL POWER SUPPLY PCA A20 CPU PCA A6 WIDEBAND PCA A4DIGITAL MOTHER BOARD PCA A2 FRONT PANEL PCA A1 KEYBOARD ASSEMBLY J FRONT elu053 eps Figure 4 5 Analog and Digital Assemblies 4 19 Clearing Ghost Images from the Control Display After prolonged periods of displaying the same message on the Control Display you may notice a non uniform brightness of pixels across the display This phenomenon can be cleared up by lighting up the whole display and leaving it on overnight or at least several hours Proceed as follows to burn in the Control Display 1 2 3 4 5790 press Press UTIL MENUS followed by Diags softkey Press Front Panel Tests softkey Under the Display label press the Control softkey Maintenance 4 Replacing the Clock Calendar Backup Battery 5 Press the On softkey This causes all Control Display pixels to light Press the RESET key or press PREV MENU six times to return to normal operation after an overnight or equivalent burn in period 4 20 Replacing the Clock Calendar Backup Battery To replace the lithium button type battery on the CPU Assembly
197. PCA 6 34 A6A2 WB Input Protection DCA 6 36 ATO Transter PCA ie pte Donee teer ae 6 41 A10A1 Precision Amplifier enne 6 43 10 2 High Voltage Protection Amplifier PCA 6 45 A10A3 High Gain Precision Amplifier 16 47 6 51 AIGDACPA ooa 6 55 A16A1 DAC Filter PCA 16 57 A17 Regulatorr Guard Crossing 6 61 ANS Filter PCA PER A19 Digital Power Supply 1 kb eeh ask asa asa ik LA Chapter 1 Introduction and Specifications InttodUctiOnD i ie D ERR bee teas Service Information ER Trg Safety Instruct DURER Tm Input Source Limitfs 5 6 ra eise tener ARD ende RR Ades Proper Fuse Usage ie eee rete eta ene deor e Grounding of the 5790A ene Proper Power Cord Do Not Operate in Explosive Atmosphere
198. R 15PF 20 50V COG 697524 LS v 17 CAPACITOR POLYPROPYLENE 0 033UF 10 63V 5MM 721050 1 LS RADIAL TAPE C18 19 CAPACITOR CAP POLYPR 0 33UF 5 50V HERMETIC 876367 C20 C22 CAPACITOR ROSR CAP CER 33PF 596 50 714543 gt CAPACITOR ROSR CAP CER 82PF 2 50V COG 714857 26 27 CAPACITOR R05A CAP POLYES 2200PF 10 50V 832683 28 29 R05R CAP TA 10UF 20 35V 816512 4 C36 37 C30 33 CAPACITOR R05R CAP TA 22UF 20 10V 658971 3 CAPACITOR FILM POLYESTER 0 1UF 10 50V 5MM 649913 16 LS RADIAL TAPE CAPACITOR CERAMIC 4700PF 20 100V COG RADIAL TAPE 743427 C42 43 CAPACITOR R05A CAP POLYPR 0 15UF 10 100V 912688 p E 35 TAPE Wu pem i RE Wes eewwreswemmo H p he sess comevwwewemwemeanem 2 BRE od RE 92 Lll sss 92 List of Replacable Parts 6 Parts Lists P JFET ROSA TRANSISTOR SI P JFET SEL TO 92 852141 1 4 RESISTOR 5 5 1 5 0 25 780585 7 8 9 17 28 31 ENT RESISTOR A52R RES MF 33 2K 1 0 125W 100PPM 2913993 1 RESISTOR CARBON FILM 560 5 0 25W RADIAL TAPE suo 1 wo p FUR RESISTOR CARBON FILM 330 596 0 25W
199. ROM 2 19 5790 Service Manual 2 20 2 33 2 34 2 38 2 36 2 37 Electrically Erasable Programmable Read Only Memory EEPROM IC U13 1s an EEPROM The socket accommodates a 32 K X 8 device 32 KB of storage A jumper is provided to allow an 8 X 8 8 KB device to be used in place of the 32 KB device The 5790 is shipped with a 32 KB EEPROM installed The are designed so that writes to the device are prevented by holding the output enable line NVMOE low Diodes CR5 CR6 and CR8 together with the resistor R6 perform a wired OR function for three signals that control NVMOE Components R6 CR6 and C17 hold NVMOE to a valid logic low for typically 37 3 ms during the power up 26 8 ms minimum 49 6 ms maximum Diode CR7 provides a discharge path for C17 on power down allowing the operator to quickly turn the 5790A off and then on again without interfering with the power up charge time of the capacitor Diode CR8 allows the normal microprocessor read of the device to take place And diode CR5 allows power monitoring IC U1 to hold NVMOE low when the 5 V power supply drops below 4 5 V on power down or during the power glitches DUART Dual Universal Asynchronous Receiver Transmitter Circuit The 68C681 DUART U31 has several functions Its primary function is to provide the asynchronous serial lines that communicate with the Guarded Digital Controller over the fiber optic path off the Digital M
200. S S DEVICES OVER ANY SURFACE gt 9 HANDLE 5 5 DEVICES ONLY STATIC FREE WORK STATION 10 ONLY ANTI STATIC TYPE SOLDER SUCKERS SHOULD BE USED 11 ONLY GROUNDED TIP SOLDERING IRONS SHOULD BE USED 7 AVOID PLASTIC VINYL AND STYROFOAM IN WORK AREA PORTIONS REPRINTED WITH PERMISSION FROM TEKTRONIX INC AND GERNER DYNAMICS POMONA DIV Dow Chemical Chapter 4 Maintenance Title Page T 6 4 3_ Cleaning Air Filter eere 4 3 General Gleaning nitro th e deo 4 3 Cleaning Sl er esie tede 4 4 Access Procedures Ms 4 5 Top and Bottom 2 2 212 20 1 000000000000 4 4 Digital Section 4 4 Analog Section COyets beu eine e 4 4 Rear Panel Removal and Installation 4 4 Rear Panel Assembly 4 6 Front Panel Removal and Installation 4 7 Display Assembly Removal and Installation 4 7_ Keyboard Assembly Removal Installation 4 7 Analog Assembly Removal and Installation 4 8 Digital Assembly Removal and Installation 4 4 Power Transformer Removal and Insta
201. SETL CR5 SHT2 u31 10 SHT5 U32 3 58HT5 XMT ZAHCT244N t Yt BRPDRTINT 2 72 BRBIEEEINT U10 B SHT1 y BRPDIK 05 10 1 4 YA BRESET 25 q TYP 457244 U10 10 SHT1 KEYBRDINT Yi 5 11 v2 2 13 U10 2 5HT1 BPSFAILINT as tS PSFAILINIR Y4 A4 17 4 20RESET 12 2 1 025 U31 34 SHT5 u3 U4 9 SHT1 3 6864MHZ 11 4 3 6864MHZCLK 5 31 32 5 8 0 22UF 3TURN CLK 2 5 CAPACITORS AND C3 ARE NEAR CONNECTOR P220 57004 6301 3 88864MHZCLK 6864MHZCLK AND THE 3 68664MHZCLK TRACES OUTED NEXT TO EACH OTHER ON AN INNER AWAY FROM OTHER TRACES BYPASS CAPACITORS C12 0 1 7 UF 5790A 1020 4 of 5 Figure 7 18 A20 CPU PCA cont 7 54 Schematic Diagrams 7 5 lt 1 DATA 8 lt 15 0 gt Designator ui 92 FANI UA DUART CIRCUITRY P120 Ci SHT4 1K 1 s R57 R52 CR2 F i Y 1 14007 U10 4 SHT1 1 1 8W DRTDTKa P120 C2 SHT4 N 12 1 8W U2 6 5HT1 ues ug EXDUARTINT GCIACK 1 1 8 12 1 8W EANINT U10 6 SHT1 DS75451N 68C681CP A4
202. SHT1 _ 12 12 1 A2 A4 AB 6 9 10 12 A13 Als BYPASS CAPACITORS NOTE PART MOS 27010 IS INSTALLED IN PCB FOR U23 AND 024 15 16 041 52 DE 5790 1020 3 of 5 Figure 7 18 A20 CPU PCA cont 7 53 5790 DATA 0557 0 gt ADDRESS BUS lt 32 1 gt 030 1 AIS Z4HGT244N_ At Yi REAR PANEL Y2 i P220 A4 Y4 028 FRONT PANEL 120 1 R56 SHT5 02 PAN2 R85 SHTS ZA4HCT244N At Yt A2 Y2 4 Y4 928 SHCT244N At Y1 2 Y2 AS 9 5 1 As U31 8 SHT5 R WR 929 U6 17 SHT1 RRPNLEN FPWRITEs TXDB usi 11 SHT5 9 6 1 813 27 5 72 U21 29 SHT3 U33 1 SHT5 RPR WR ERNTPNLCS U6 18 SHT1 u6 15 SHT1 RESELE U1 5 SHT1 RE
203. SI 1KV 1A DO 41 707075 11 CR23 24 CR29 34 CRD RO5R I REG DIODE 3MA 10 SEL TO 226AC 1 oam poemas _ mw _ sem 1 i _ m H ______ oe 1 Tnne anas mes e nean anan mem 1 _ Des mmm e 7 meracmenesaisemcumemomoen mem 2 _ 6 65 5790 6 66 28 29 SCREW 6 32 250 PAN PHILLIPS STEEL ZINC 152140 CLEAR LOCK Q3 Q7 10 NPN PWR MPS U10 TRANSISTOR SI NPN 300V 10W TO 107646 202 PNP PWR 2N5415 TRANSISTOR SI PNP 200V 1W TO 39 276899 NPN PWR TIP120 TRANSISTOR SI NPN 60V 65W TO 220 386128 RESISTOR A52R RES CF 5 1 5 0 25W 441287 R H RESISTOR A52R RES CF 4 7K 5 0 25W RESISTOR A52R RES CF 12 5 0 25W RESISTOR A52R RES MOX 10K 5 2W RESISTOR A52R RES CF 2 5 O 5W amm RESISTOR A52R RES CF 33K 5 0 25W RESISTOR A52R RES CF 51K 5 0 25W RESISTOR A52R RES CC 10K 5 0 25W 148106 TP1 5 TP8 TP10 JUMPER R05R JUMPER WIRE NONINSUL 0 200CTR 816090 TP12 13 6 1 2 1 4 5 1 R3 R12 RESISTOR A52R RES CF 100K 5 0 25W 348920 4 5 10 13 ZENER UNCOMP 1N753A 6 2V 5 20MA DO 35 TAPE 325811 ZENER UNCOMP 1N974B 36V 5 3 4MA 400MW
204. SNS LO R46 R47 4 gt FROM ADC 5790 1015 DC SNS LO i 2 of 3 3 POLE FILTER Figure 7 12 A10 A D Amplifier PCA cont 7 34 Schematic Diagrams 7 016 44 SHT 2 016 13 SHT 2 015 12 SHT 016 11 SHT 2 016 10 SHT 2 016 9 SHT 2 016 8 SHT 2 u16 7 SHT 2 WB SELX 43 8 SHT 1 U46 46 SHT 2 amp At U8 42 SHT 1 BYPASS 016 45 SHT 2 Ue 9 45 SHT 4 CHOP ON os s SHT 1 x 4OSEL 013 16 SHT 4 Luis L24 A08ELX SHT 4 25 DIAG SEL 45 9 sur 4 016 17 SHT 2 R36 95 SHT 2 024 42 SHT 2 5 8 SHT 1 18 9 SHT 1 21 DIGITAL CONTROL SPARES POWER SUPPLIES H H HUH 5790A 1015 3 of 3 Figure 7 12 A10 A D Amplifier PCA cont 7 35 5790 CH CH SH R53 12 g SERIES d Eon nid PAS poa Q C53 R38 G R51 54 U7 5790A 1616 Figure 7 13 A16 DAC PCA 7 36 Schematic Diagrams 7 5 R110 C105 12 22 COM COM U8SUPPL Y 30 FR2 Designaton LHCOM FR1COM U6SUPPLY UBSUPPLY 5FR1 TESTPOINTS SCOM REF13 REFCOM CH1 SERIES B 0 22UF IN d CH1 SHUNT 1 COM DAC SENSE CA
205. STOR R05A RES CF 10K 5 0 25W 697102 1 R106 107 RESISTOR R05A RES CF 47 5 0 25W 822189 2 R108 RESISTOR A52R RES CF 4 7M 5 0 25W 543355 1 TP1 2 TP4 9 JUMPER R05R JUMPER WIRE NONINSUL 0 200CTR 816090 8 DMOS 5400 SMR IC DMOS QUAD ANALOG SWITCH SOIC 928291 1 02 3 IC ANALOG SWITCH DG444 12 4 20V 85 910708 2 OHMS SPST QUAD NC DIP16 TUBE U3 U34 BIPOLAR 339 IC COMPARATOR QUAD 14 PIN DIP 387233 2 BIFET LF356N IC OP INPUT 8 PIN DIP 472779 1 j 5700A 4H09T RMS CONVERTER TESTED 400 OHM A GRADE 842591 1 6 39 5790 OHMS QUAD BILATERAL LO CAPACITANCE DIP16 TUBE INPUT DIP14 TUBE T PREP AMMO BOX DO 35 TAPE NN 1 Static sensitive part 6 40 List of Replacable Parts 6 Parts Lists or s czo R37 CR8 CRT 125 066 V 83365 vsn 5790 1610 Figure 6 10 10 Transfer 6 41 5790 Table 6 12 A10A1 Precision Amplifier
206. Section Detailed Circuit Description Filter Assembly 8 s uuu Rettore PES sss Unregulated CH Unregulated LH Unregulated 17 SR Supplies Trac Circuit a nam un an qunan kaiaspa cecinit Unregulated Regulator Guard Crossing Assembly 17 Voltage Regulator Regulated LH Supplies sss sees eee Regulated 17 S Supplies sees eee eee Regulated 15 CH Supplies eene FR SUPPLY ices Supply este i Dos aus Sea Guarded Digital Control Circuitry Transfer Assembly A10 sss Input Signal Paths sse Precision Amplifiers Thermal Sensor Circuit esee Digital Interface and Control ii 2 20 2 20 2 20 2 20 2 24 2 24 2 26 2 26 2 28 2 28 2 28 2 28 2 29 2 29 2 29 2 29 2 30 2 30 2 36 2 83 2 84 2 90 2 96 2 97 2 98 2 99 2 100 2 101 2 102 2 103 2 104 2 105 2 106 2 107 2 108 2 109 2 110 2 111 2 112 2 113 2 114 2 115 Calibration
207. T 1 OUT OUTS OUT OUTS OUTs OUTS OUT a ZB10K cU2S 1 U27 9 18 1 58 1 SHT 3 2 5 27 568 IK 12 28 1 SHT 1 C86 n 100 Lr Z9 5 SHT 1 V 28 3 SHT 1 gt 210 4 SHT 1 1 1 INA INS 1 IN 1 125 1 027 9 10 CLR Slip 5 5 27 Z18 G SHT 12 1K FETS 210 2 SHT 1 1 8 E gt U24 1 SHT 3 gt UR 1452568 12 Uis i sHr RANGE COMP 184 11 Sur 1 ENP PROT Hceo TP13 SER 025 1 026 1 SHT 3 1121 19 SHT 3 5790A 1006 3 of 4 Figure 7 5 A6 Wideband PCA Option 03 cont 7 20 Schematic Diagrams 7 TESTPOINTS UIN MUIN WB CHOP INP PROT GND DC OUT GND 4 5 RANGE COMP GND INT CLR IN 5 5 GND
208. TAPE E E 5044 E Ir TRANSCEIVER SOIC IC CMOS 68C681 DUAL CHANNELUARTPLCCTAPE CMOS 68C681 DUAL CHANNEL UART PLCC TAPE 866785 1 DRIVERS 50128 TAPE o Gl CALENDAR ICM7170 5V PARALLEL ALARM SO24 TAPE BIPOLAR LM324 SMR IC OP AMP BIPOLAR LM324 SMRJC OP AMP QUAD LOW POWER SOIC LOW POWER SOIC 74259 1 F ENCAPSULATED SMD TAPE HM CRYSTAL 32 768KHZ 20 169PPM 12 5PF PLASTIC 106754 ENCAPSULATED SMD TAPE 21 RESISTOR NETWORK CERMET BUSSED 15 5 16 1589028 TERM 3 3K 596 0 125W 200PPM 4012 TAPE RESISTOR SMR RES CERM SOIC 16 PIN 15 RES 4 7K 2 838060 RESISTOR SMR RES CERM SOIC 16 PIN 15 RES 100K 2 910745 eer 1 Static sensitive part 6 Parts Lists List of Replacable Parts Je 212 1212 6212 5790A 1620 8215 0 sen d 1 112015 621 0112 Zu 820 i 282 n Lais De oH 1 010 JUL _ t 9012 9n ein T 6n 9 E BETR 691 i75 1 0141 Gdl Pdl Lat
209. TXDA IXDA IXDB IXDB P220 A32 SHT4 A2 RXDA L RXDA RXDB RCVB 74 2 2 AA 24 2 7007 INTRCNTL2 10K 1 8 R53 CRS DOS De SPARES TOK 8 AAA 5 03 9 5 5 11K 1 4 505 04 0 4 LM324N 205 R54 1X 1 8W opa LE 575 24 2 R61 diu o DOO 14 71 84 BAAB 010 1 SHT1 z2 TOR 1M IPS SCDRTCS IP4 U6 22 SHT1 IPS 1 1 8W 2 4 FANINT _ U10 6 SHT1 b U10 9 SHT1 Z2 13 SHT2 DS75451N X2 X1 CLK SN75189A4 3 8864MHZ 104 9 5 1 5 11 5 74 68 681 A4 TXDA AS TXD8 A2 RXDA At RXDB B97 07 0 7 206 08 oP amp 502 05 0 5 DO4 D4 DOS D3 002 0 2 1 1 0 1 n 080 ADCLKCS RDL SN75189Ad WRI 3 CLKCALINT zz zzz Se U3 9 SHT1 U26 1 R WR i54 SHT4 U31 8 5HT5 eee 044 SPARE XDUARTCS gt 2 U6 21 SHT1 Ria N C SN75189A4 SN7S189A4 15 N C gt 49 U2 2 SHT1 U25 8 SHT4 X2 5 4 32 768KHZ U44 210 T v 32 P 22PF 2X 7 2 LITHIUM ICM7170 A 3 0V E4
210. Thermocouple type transfer devices have a square law response Stability A measure of the freedom from drift relative to a reference value over time and over changes in other variables such as temperature Note that stability is not the same as uncertainty Standard A device that 15 used as an ext value for reference and comparison Standard Cell A primary cell that serves as a standard of voltage The term standard cell often refers to a Weston normal cell which is a wet cell with a mercury anode a cadmium mercury amalgam cathode and a cadmium sulfate solution as the electrolyte Systematic Error Any error that remains constant or varies in a predictable manner as successive measurements of the same quantity are made under effectively identical conditions Note that a known systematic error can be compensated for with a correction whereas a random error cannot Also see random error Temperature Coefficient A ftor used to calculate the change in indication or output of an instrument as a result of changes in temperature Changes in temperature contribute to instrument uncertainty by an amount determined by the temperature coefficient Test Uncertainty Ratio The numerical ratio of the uncertainty of the measurement system or device being calibrated or verified and the uncertainty of the measurement system or reference device Appendices A Glossary of AC DC Transfer Related Terms Thermal EMF The voltage gener
211. VE 735365 117 217 CONNECTOR DIN41612 TYPE C M RT ANG 64 PIN 807800 7 R1 R4 R59 RESISTOR A52R RES MF 113 0 1 0 125W 100PPM 484238 R2 R8 RESISTOR A52R RES MF 2 67K 1 0 5W 100PPM 161430 2 R5 R11 RESISTOR METAL FILM 203 851191 2 0 1 0 125W 100PPM AXIAL TAPE RESISTOR METAL FILM 2 61K 851571 1 0 1 0 125W 100PPM AXIAL TAPE RESISTOR A52R RES MF 2 67K 0 1 0 125W 25PPM 340596 RESISTOR A52R RES CF 10 5 0 25W 340075 List of Replacable Parts 6 Parts Lists R21 RESISTOR R05A RES MF 200 1 0 25W 100PPM 820282 R22 RESISTOR METAL FILM 806 1 0 25W 100PPM RADIAL TAPE R52 RESISTOR A52R RES MF 1K 1 0 125W 100PPM R54 RESISTOR A52R RES CF 1 8K 5 0 25W TP1 TP4 TP6 JUMPER ROSR JUMPER WIRE NONINSUL O 200CTR 816090 TP8 10 TP12 55 58 058 CMOS 22V10 IC PROG ARRAY LOGIC PRGMD 5790A 904719 90780 U59 U63 CMOS 74HC4020 IC CMOS 14 STAGE BINARY COUNTER 807701 060 BIPLOAR TL7705A IC VOLT 4 55 SENSE 780577 INPUT IC MEMORY SRAM 6264 64KB 8KX8 5V 100NS DIP28 TUBE MEMORY SRAM 6264 64KB 8KX8 5V 100NS DIP28 TUBE 783332 U64 LL EPROM PROGRAMMED 27 256 U64 885673 CMOS 2692 IC CMOS DUAL 28 PIN 876318 A 5 CONNECTOR SOCKET DIP 300CTR 24 812198 CONNECTOR SOCKET DIP 600CTR 28 PIN 448217 o 6 59 5790
212. W 200PPM 1206 746636 RESISTOR SMR RES CERM 124 1 125W 100PPM 1206 867499 BIPOLAR AD707K SMR IC OPAMP ULOW DRIFT LOW NOISE SO8 887120 BIPOLAR LT1223 IC OP AMP CURRENT FEEDBACK 100MHZ DIP 914130 ZENER UNCOMP MMBZ5231B 5 1V 5 20MA 225MW SOT 837179 23 TAPE ZENER UNCOMP BZX84C12 12V 5 5MA 225MW SOT 23 TAPE 866822 ZENER UNCOMP MMBZ5248B 18V 5 7MA 225MW SOT 23 TAPE 876433 4 Static sensitive part 6 42 List of Replacable Parts 6 Parts Lists RT co 04 cs inum DE 05 TET EA For Cre Tk 9 RS o he ia Tal 5790 1691 Figure 6 11 A10A1 Precision Amplifier 6 43 5790 6 44 Table 6 13 10 2 Protection PCA Ref Des Description t Notes p Number Qty CR1 2 DIODE SI PN FDH300 125V 200MA RADIAL LEAD 844647 2 1 PREP DO 35 TAPE CR3 CR7 8 DIODE MMBD1501 SMR DIODE SI 150V 200MA SOT 867072 3 4 23 01 4 FET DMOS N CH R05A TRANSISTOR SI N 782490 4 1 DMOS 500V TO 92 Q5 8 MOSFET P CHN RO5A TRANSISTOR SI P 782508 4 4 MOS 500V TO 92 R1 16 RESISTOR SMR RES CERM 330K 746776 16 4 5 125W 200PPM 1206 R17 R20 RESISTOR SMR RES CERM 510K 746800 2 4 5 125W 200PPM 1206 R18 R30 RESISTOR SMR RES CERM 220 746347 2 4 5 125W 200PPM 1206 R21 28 RESISTOR SMR RES CERM 10 746214 8 4 5 125W 200PPM 1206 RT1 THERMISTOR THERMISTOR DISC NEG 200 5
213. a differential gain stage with a differential input voltage of zero volts Applying a voltage to the resistor on one of the islands causes that island to heat up This in turn heats the transistor reducing its base emitter voltage causing an imbalance in the differential collector current This differential current change is converted to a single ended error current by the current mirror consisting of the two PNP transistors of U101 Op amp 0102 integrates this error current converting it to an error voltage The output of 0102 pin 1 is then passed through a square root circuit consisting of the other half of U102 and U103 The resultant error signal is then applied to the other side of U5 through R103 heating up that side of the sensor When the heat on both islands of the FTS is equal the differential error current reaches zero and the circuit is in equilibrium An over voltage protection circuit monitors the base emitter voltage of the sensor transistors As with other silicon junctions the base emitter junction on the FTS transistors exhibits a 2 mV C temperature coefficient When the base emitter junction falls below 200 mV the output of U4 goes from 15 V to 15 V turning on Q1 This shorts the sensor input to ground through the diode bridge CR7 through CR10 and allows the FTS to cool When the temperature falls and the base emitter voltage increases past the 200 mV threshold U4 again changes the state and turns off the clamp During a co
214. al the signal at TP9 RANGE COMP causes gate 027 pin 11 to go high and turn on FET 011 With on the interrupt line at P206 pin 15 low thereby telling the digital system to range up If the up ranging mechanism reaches the 7 V range and U13 pin 1 does not indicate that the sensor amplifier is within the normal range an overload condition exists and Wideband mode is turned off Diodes CR20 CR21 Q9 Q10 and associated components form a backup clamp for the RMS sensor and are activated only if the CR16 through CR19 protection bridge fails It clamps the sensor AC input pin 10 to 3 25 V Wideband Frequency Counter A circuit on the A6AT assembly conditions signals for use by the frequency counter circuit on the A15 A D Amplifier assembly The counter function for Wideband mode is provided by buffer Q23 and the counter section of the A6A1 assembly The output of RMS sensor buffer amplifier U5 15 connected to emitter follower Q23 through resistor R143 Q23 isolates the counter circuit from the signal measurement path The output of Q23 is attenuated by R106 and R141 and passed to the A6A1 assembly input at pin 14 of the SIP connector The input is sent to comparator U1 at pin 2 Comparator U1 produces an output of 3 4 V HIGH or 0 3 V LOW whenever the input exceeds the input threshold of about 230 mV The output of comparator U1 is therefore at normal logic levels and can be used by divider U2 to divide down by 16 For frequencies g
215. al setup for range but with open input 2 Setthe DAC so that the input of the instrumentation amplifier should be 1 0 This is done by multiplying the desired A D input by IA to reflect to input terminals and then multiply by DI to figure what the DAC should be set to 3 Measure sensor output with x1 A D range Possible errors include Error Wideband 2 2 mV Range Failed Error Wideband 2 2 V Range Failed Error Wideband 22 mV Range Failed Error Wideband 220 mV Range Failed Error Wideband 7 mV Range Failed Error Wideband 70 mV Range Failed Error Wideband 700 mV Range Failed Error Wideband 7 V Range Failed elu070 eps These errors indicate a fault on the A6 Wideband assembly Trace from the point where the chopper comes in WB CHOP HI through the amplifiers to the input of sensor Test Step WFREQ Wideband Frequency Measuring This measures the chopper frequency via the Wideband assembly The error from this test 1s Error Code 3017 A6 Wideband Frequency Measurement Failed elu071 eps Troubleshooting Introduction This error indicates that the fault is probably on A6 Wideband assembly There is a slight chance the fault is on A15 A D Amplifier assembly Check that the chopper AC signal Is being transmitted to the A6 Wideband assembly Trace through amplifiers to input of sensor From there it is routed through prescalers and filters to the COUNT motherboard line back to the A15 A D Amplifier a
216. al tests fail 8255 and 8254 tests it is more likely that there 15 a problem with the guard bus interface from the A17 Guard Crossing assembly 5 9 Troubleshooting Introduction Test Step ADSELFTEST WD Internal Selftest When diagnostics are first started the communication channel with the A D chip is restarted If you get an Error Code 1604 Guard Crossing CPU A D Error suspect the serial communication hardware between the DUART on the A17 Guard Crossing assembly and U24 on the A15 A D Amplifier assembly This test proceeds as follows 1 Test U24 by measuring reference and ground internally 2 024 measures reference internally 3 U24 measures ground connection internally 4 Precharge U24 filter to zero then remeasure reference internally with filter connected Possible errors include Error Code 3003 A15 A D Reference Selftest Failed Error Code 3003 A15 A D Reference Filter Selftest Failed Error Code 3003 A15 A D Zero Selftest Failed elu057 eps These errors indicate a possible fault on the 15 A D Amplifier assembly On the A15 A D Amplifier assembly check RCOM and reference voltages Connect the DMM LOW to the RCOM test point Test Step ADZEROS A D Zeros This tests the instrumentation amplifier and A D range zeros The test proceeds as follows 1 Connect both inputs of instrumentation amplifier to RCOM 2 Measure each range 10 1 10 Possible errors include Error Code 3004 A15 A
217. al than the second CH1 FLOATING is clocked into a flip flop U14 to ensure an accurate waveform To clock in this waveform U7 generates the clock inputs for U14 The output Q1 pin 5 from U14 creates SERIES A which switches Q7 The output 1 pin 6 is inverted by 035 creating SHUNT which switches The output 017 which is a TTL level is also amplified by components Q33 Q34 VR11 VR12 and 44 46 so it switches from 0 to 18 V creating CH1 SERIES B which switches Q4 and Q5 DAC Filter Circuit The DAC Filter Circuit is located on the DAC Filter SIP Assembly The dominant pole of the five pole Bessel filter is near 30 Hz This gives 80 dB of rejection at 190 Hz DAC Output Stage The output stage of the DAC assembly consists of the DC Amplifier Hybrid Assembly 4HR6 and the output buffer circuitry Like the Reference Hybrid the DC Amplifier Hybrid is constructed of surface mount the components except the precision op amp U2 on a ceramic substrate hybrid bonded to a resistor network This hybrid is temperature controlled by a heater control circuit in the same manner as explained on the Reference Hybrid Transistor Q3 supplies appropriate power to the heater resistor The DC Amplifier Hybrid consists of a precision op amp U2 with a bootstrapped power supply Q1 Q2 R1 through R4 and VR1 through VR2 The op amp has low noise and low offset It is bootstrapped to improve the common mode rejection in its n
218. ale Adapter equivalent minimum 1 See Table 3 13 AC SOURCE MAXIMUM UNCERTAINTY for specific Voltage Frequency and Uncertainty information 5790 Service Manual 3 20 VOLTAGE NOMINAL FREQUENCY 792A CORRECTION PPM 792A 5790A DC DC DC 792 5790 762 ACMEAS DC averace 2 702 799 CORR 5790 792 792 DC 792 10 EXAMPLE VOLTAGE NOMINAL 20V cidem DC 1 713135 1 713146 zd 1 792A CORRECTION PPM 24 792 MES CREE 1 713141 55 1er 5790 1 999799 1 999801 _ 999800 2 m m DC AVERAGE 792 1 713141 DC 5790 1 999800 1 999800 1 713188 14 1999858 1 713188 1 713141 10 ACMEAS ne Figure 3 6 Worksheet for 2 V to 1000 V AC Calibration Points elu028 eps Calibration and Verification 3 Periodic Calibration VOLTAGE NOMINAL FREQUENCY 5700A ERROR DISPLAY FROM TABLE 3 3 POSITIVE 5700A ERROR DISPLAY FROM TABLE 3 3 NEGATIVE 792A CORRECTION PPM 792A DMM READING DC 792 I DCI 2 AC ACMEAS NOMINAL 792 792 CORR 792 105 elu029 eps Figure 3 7 Worksheet for 60 mV to 600 mV AC Calibration Points Proceed as follows to perform AC calibration of the main inp
219. alog Motherboard The POP signal from U58 is a reset line sent to the analog assemblies DUART dual asynchronous receiver transmitter U65 provides the serial communication channel to the A D chip on the A D Amplifier A15 Assembly HGRCV and HGXMT are the serial communication lines from and to the A D chip Inguard CPU Interrupts The Inguard CPU microprocessor handles many different interrupts These are listed in Table 2 12 in order of priority with the highest priority interrupts first Table 2 12 Inguard CPU Interrupts Description ise RDRF Receive Data Register Full ORFE z Overrun Framing Error TDRE Transmit Data Registry Empty PER Parity Error 2 74 2 75 2 76 Theory of Operation 2 Analog Section Detailed Circuit Description Transfer Assembly A10 Figure 2 5 is a block diagram of the A10 Transfer assembly This assembly contains the transfer switches 22 V 220 V dividers precision AC amplifiers FTS and associated control and support circuitry This assembly also contains input selection relays and provides the drive signals for the Analog Motherboard relays The 700 V 1000 V divider is located on the Analog Motherboard TRANSFER INPUT SWITCH INPUT gt ATTENUATORS SWITCHING AND PROTECTION FLUKE MODULE THERMAL RMS A SENSOR CIRCUIT INPUTS 1 FROM CHOPPER TO A15 A D ON A15 AMPLIFIER AID ASSEMBLY AMPLIFIER elu007 eps Figure 2 5 A10 Transfer Assembly Blo
220. an automated calibration and verification system to accomplish the procedures described here To minimize time you spend on repetitive measurements and calculations you may want to automate the following procedures to the greatest extent possible Chapters 5 and 6 of the User Manual document the remote interfaces and commands that can help you with the calibration 3 3 5790 Service Manual Note technical paper describes the system in use at Fluke to calibrate and verify the 5790A Calibration and Traceability of a Fully Automatic AC Measurement Standard by David Deaver presented in the NCSL Workshop and Symposium 1991 Reprints are available from Fluke 3 6 How Calibration Memory is Organized Three sets of calibration constants are maintained in memory Associated with each set of constants is the date and ambient temperature of the calibration Figure 3 1 shows the three sets of calibration constants and how they are purged following a calibration store operation The three sets of constants are described below from newest to oldest 1 The active set This is a volatile memory that normally contains a copy of the contents of the stored set of calibration constants The only time it contains different data is after you perform calibration of one or more ranges but before you store the updated constants After calibration you must either store or discard the updated constants before you resume normal operation 2 The
221. anel CPU Interface 5790 2 17 2 18 2 19 2 20 2 21 2 22 2 23 2 24 2 25 2 26 2 27 2 28 2 29 2 30 2 31 2 32 2 33 2 34 Digital Section Detailed Circuit Description Digital Power Supply Assembly 5 V Power Supply 12 V Power Supplies 35 V Power Supply 75 V Power Supply 35 V and 75 V Shut Down CPU Assembly 20 Power Up and Reset Circuit Clock Generation teen ccu ME Electrically Erasable Programmable Read Only Memory EBEPROM e DUART Dual Universal Asynchronous Receiver Transmitter Clock Calendar Circuit Clock Filter Circutt CPU to Rear Panel Interface CPU to Front Panel Interface Front Panel Assembly A2 aa Clock Regeneration Circuitry Refresh Failure Deject Circuittry Decoding and Timing Circulttry a Control Display Measurement Display Circuttry a Keyboard Scanner Circuitry LED CIO SET Keyboard Assembly Analog
222. anges are verified in a similar manner Obtain 8 copies of Table 3 15 with the 5700A errors recorded in the table one for each of the 8 voltage ranges Enter the range 7 V 2 2 V 700 mV 220 mV 70 mV 22 mV 7 mV and 2 2 mV in the box at the top of each table Enter the attenuator corrections as required for each range and add up the errors and enter the TOTAL ERROR column The total error is the sum of the errors of the 5700A and all attenuators used for that frequency Proceed to verify each range by first establishing the 1 kHz reference at the beginning of each range 10 11 12 13 14 15 16 17 Calibration and Verification 3 Verification To establish the 1 kHz reference set the 5700A to 3 2 V and 1 kHz Let the 5790 measure this value Record the value in Table 3 15 Press the SET REF soft key on the 5790 Proceed to the first frequency listed in Table 3 15 and adjust the 5700 to the TOTAL ERROR value sign and magnitude listed in Table 3 15 Read the error on the 5790A error display and record in the WIDEBAND input verification test record Table 3 16 Proceed to the next frequency in the table and set the 5700A to 3 2 V the error values are set relative to the nominal 3 2 V level Adjust the 5700 to the TOTAL ERROR value sign and magnitude listed in Table 3 15 and read and record the error in Table 3 16 Repeat step 14 for all frequencies in Table 3 15 for that range
223. ated calibration system Use the same procedure as for periodic calibration as previously defined except set the rear panel CALIBRATION MODE switch to SERVICE and the CALIBRATION STORE switch to ENABLE This switch setting generates prompts that request many more stimuli points than used in periodic calibration plus the Xfer Offset Adjustment and the Wideband Amplifier Rolloff Adjustment the latter only if Wideband Option is installed Table 3 10 lists the main input calibration steps called for in service calibration WIDEBAND Service Calibration uses the same steps as the Periodic Calibration Note that the I2 I1 steps at the beginning of AC calibration have only a 1 absolute tolerance but a very tight drift requirement 3 35 5790 3 36 Table 3 10 Calibration Steps Service Calibration Voltage to Apply Sensor turnover 0 7 Sensor turnover 0 7 1000 V Positive DC 1000 V Negative DC 700 V Positive DC 700 V Negative 220 V Positive DC 220 V Negative DC 70 V Positive DC 70 V Negative DC 22 V Positive DC 22 V Negative DC 7 V Positive DC 7 V Negative DC 2 2 V Positive DC 2 2 V Negative DC 700 mV Positive DC 700 mV Negative DC 220 mV Positive DC 220 mV Negative DC 70 mV Positive DC 70 mV Negative DC 22 mV Positive DC 22 mV Negative DC 7 mV Positive DC 7 mV Negative DC 0 7 V DC 0 7 DC 1000 V 1000 V 600 V DC 600 V DC 2
224. ated from the unguarded CPU assembly A20 by a fiber optic link that asynchronously transmits serial data On the transmit side the microcontroller transmit output XMT controls a 75451 U57 which drives fiber optic transmitter mounted on the Analog Motherboard Receive signal RCV comes from fiber optic receiver also mounted on the Analog Motherboard The receiver converts the light signal to TTL levels that become the RCV signal at microcontroller fiber optic cable links fiber optic transmitter the Analog Motherboard to the fiber optic 2 31 5790 Service Manual 2 32 2 72 2 73 on the Digital Motherboard Another fiber optic cable links the other receiver transmitter pair on the motherboards Interface to Guarded Digital Bus The interface to the guarded digital bus consists of a 74HCT245 055 74 244 052 74HC137 1 53 resistor packs 752 753 and Z54 and the POP line from 058 U52A and U52B buffer various control and address lines Resistors from Z52 pull the lines of 0524 to the desired inactive states when BUSEN is at a logic high disabling the bus U55 is a bi directional data bus buffer 00 07 Resistor packs 753 and 754 match the lines of the buffered data bus reducing reflected noise IC U53 performs a 3 to 8 decode of the address lines AB3 ABS generating 8 select lines CS0 CS7 on the guarded digital bus These 8 signals select the various components on the An
225. ated when two dissimilar metals joined together are heated Treability The ability to relate individual measurement results to legally defined national standards through an unbroken chain of comparisons Treability requires evidence produced on a continuing basis such as calibration records that the measurement process 15 producing results for which the total measurement uncertainty relative to national standards is quantified Transfer See transfer Transfer Error Error induced by the process of comparing one standard or instrument with another This does not include the uncertainty of the transfer standard Transfer Stability Change in the AC DC Difference correction over time with stated conditions Transfer Standard Any standard used to intercompare one measurement or source device with another Note that a transfer standard needs only to be stable for the duration of the transfer It does not need an assigned value Transport Standard A transfer standard that is rugged enough to allow the shipment by common carrier to another location True Value Also called as legal value the cepted consensus i e the correct value of the quantity being measured Uncertainty The range of values usually centered on the indicated or requested value within which the true cepted or consensus value is expected to lie with stated probability or confidence Fluke uses 99 7 36 confidence limits Uncertainty is a
226. chematic Diagrams 7 vA HERTER COMMON R23 HEATER 27 RESISTOR 18 POS HEATER SuPPLY NEG HEATER SUPPLY HEATER COMMON HERTER Q2 COLL 04 COLL 28 s REF13 HI UG COLL 13 R4 REF13 SENSE 12 190 CURRENT SINK UZ COLL REF LO CURRENT CANCEL 5790A 1H42 Figure 7 22 A16HR9 Reference Hybrid on the A16 DAC PCA 7 61 5790 7 62 Appendices Appendix Title Page A Glossary of AC DC Transfer Related A 1 B ASCIIand IEEE 488 Bus Codes 1 1 Calibration Constant Information Appendix Glossary of AC DC Transfer Related Terms Absolute Uncertainty Uncertainty that includes contributions from all sources i e treability to national standards of the standards used plus the uncertainty of the measurement process Absolute uncertainty should be used to compute test uncertainty ratio Also see relative uncertainty Accury The degree to which the measured value of a quantity agrees with the cepted consensus or true value of that quantity Accury is the same as 1 uncertainty For example an instrument specified to 1 uncertainty 15 99 curate Also see uncertainty Artift Calibration An instrument calibration technique that uses a calibration system within the instrument to reduce the number of required external standards to a small number of artift standards The Fluke 5700A Calibrator uses Artift
227. ck Diagram Input Signal Paths The 5790 has two DC 1 MHz 700 to 1000 V inputs one SHUNT input and one WIDEBAND input of these inputs except the WIDEBAND input are routed to the Transfer assembly The WIDEBAND input goes to the A6 Wideband assembly The two DC to 1 MHz inputs are identical internally but use different external connector types INPUT 1 is a Type N coaxial connector and INPUT 2 consists of five way binding posts Relays through on the Transfer assembly and and on the Analog Motherboard select the active input These relays are wired as a 2 X 3 crosspoint switch having 2 inputs and 3 outputs with the input selected by the operator and the output determined by the selected range Figure 2 6 is a simplified schematic of the input attenuator networks 700 and 1000 V Ranges For input voltages greater than 220 V 1 the 700 V and 1000 V ranges the selected input INPUT 1 or INPUT 2 is routed to the 700 V 1000 V divider by Analog Motherboard relays K3 INPUT 1 or K4 INPUT 2 A divider attenuates the input signal by a factor of 1000 and routes the signal to the Transfer assembly through connector 1110 Once on the Transfer assembly the scaled input signal 15 switched into the precision amplifier by IC analog switches U2 and U1 In the 700 V and 1000 V ranges U2 does the transfer switching between the input signal and the internally generated chopped DC while U1 simply provides a continu
228. d in routine calibration and comparison procedures Relative Uncertainty Uncertainty specifications that are relative to a reference value and not treable to national standards Also see absolute uncertainty Reliability A measure of the probability of failure of an instrument Repeatability See precision Appendices A Glossary of AC DC Transfer Related Terms Resistance A property of a conductor that determines the amount of current that will flow when a given amount of voltage exists ross the conductor Resistance is measured in ohms One ohm is the resistance through which one volt of the potential will cause one ampere of current to flow Resolution The smallest change in quantity that can be detected by a measurement system or device For a given parameter resolution is the smallest increment that can be measured generated or displayed Reversal Error Also called turnover error the difference in output of an AC DC transfer standard for the same DC input but with polarity reversed The output logged for the DC reference should be the average of the two readings Retre Error For an AC DC transfer standard the degree of agreement of output value readings when input 15 applied removed and reapplied over a specified time period RF Radio Frequency The frequency range of radio waves from 150 kHz up to the infrared range RMS Root Mean Square The value assigned to an voltage or current that results in
229. dings Always grasp an analog assembly by its upper corner ears Digital Assembly Removal and Installation Remove the CPU Assembly or the Digital Power Supply Assembly by pulling straight up at the top corners of the assembly In relation to the chassis side the CPU Assembly components face toward and the Digital Power Supply Assembly components face away See Figure 4 5 Power Transformer Removal and Installation Use the following procedure to remove the Power Transformer assembly 1 Remove the 5790 Front and Rear Panels 2 Remove the Digital Power Supply A19 and CPU A20 assemblies 3 Detach the five connectors leading from the Power Transformer assembly to the Digital Motherboard The three connectors at the rear of the assembly may not be accessible without first removing the rear fan With the two digital assemblies A19 and A20 removed the four Phillips head screws securing this fan can be accessed through holes in the chassis side Note that no two Power Transformer connectors are the same size and that each connector is keyed re connection only involves matching appropriate connectors 4 Working from the bottom of the instrument remove the Digital Motherboard A4 assembly Installing a Wideband AC Module Option 03 5 Remove the eleven screws securing the Power Transformer assembly as follows Rear Panel two screws which were removed along with the Rear Panel Front Panel two sc
230. disrupt the state of calibration and can cause instrument damage d Set the 5700A to nominal positive and then turn the knob to obtain the error display reading you recorded in Table 3 3 Wait for the 5700A U annunciator to go out Wait for 60 seconds for the DMM reading to stabilize Record the DMM reading under the 792A column in the worksheet for DC Do not record a reading for the 5790 Set the 5700A to nominal negative and then turn the knob to obtain the error display reading you recorded in Table 3 3 Wait for the 5700A U annunciator to go out Again allow the DMM reading to stabilize Record the DMM reading under the 792A column in the worksheet for DC Do not record a reading for the 5790A Apply the nominal voltage at the frequency required for the calibration step Wait for the U annunciator on the 5700A to go out Allow the DMM reading to stabilize Record the DMM reading under the 792A column in the worksheet for AC Do not record a reading for the 5790 Now do a computation to get measured AC using formulas shown in the worksheet 1 Compute the average of the 792A DC readings as shown 2 Compute MEAS using the formula shown Be sure to include the 792A correction as indicated in the formula Use nominal DC in the formula Observe the default EXACT VALUE on the display It shows allowed number of decimal places for you to enter Enter your computation of
231. e X700V 700 V Range XI000V 1000 V Range X700MV 700 mV Range Troubleshooting Introduction X220MV 220 mV Range X70MV 70 mV Range X22MV 22 mV Range X7MV 7 mV Range X2 2MV 2 2 mV Range MATCH Sensor Match XFREQ Measure chopper frequency LOOPFILT Sensor Loop The following steps are only done if the Wideband option 15 installed WOVLD Wideband Overload W7V Wideband 7 V Range W2 2V Wideband 2 2 V Range W700MV Wideband 700 mV Range W220MV Wideband 220 mV Range W70MV Wideband 70 mV Range W22MV Wideband 22 mV Range W7MV Wideband 7 mV Range W2 2MV Wideband 2 2 mV Range WFREQ Measure chopper frequency WLOOPFILT Wideband Sensor Loopfilt 5 6 Test Step MAMA8255 Motherboard 8255 This tests the motherboard 82C55 The test proceeds as follows pe cud iu xs Set CTRL register to default value read and check Set A register to default value read and check Set B register to default value read and check Set C register to default value read and check Execute pattern write read test on port A 5 5 5790 Service Manual Possible errors include B 5 8 5 6 Error Code 3000 Motherboard 8255 Control Word Test Failed Error Code 3000 A3 Motherboard 8255 Port A Test Failed Error Code 3000 A3 Motherboard 8255 Port B Test Failed Error Code 3000 A3 Motherboard 8255 Port C Test Failed elu054 eps These errors indicate a possible fault in the A3 Motherb
232. e often than every 1 14 seconds to clear 1 11 and prevent the watchdog interrupt Generation of DOGCLR2 is under software control The watchdog timer can be disabled by cutting the Jumper E1 2 28 Address Decoding DTACK Data Acknowledge Two Programmable Logic Devices PLDs accomplish address decoding and DTACK data acknowledge generation ICs 175 06 provide chip selects and generate acknowledgement signals for those devices without the DTACK lines IC U5 receives the DTACK signals from the asynchronous devices and ORs these signals together to form DTACK Table 2 4 is the memory map for the system It shows the chip select address range and notes whether address strobe or LDS lower data strobe is required Table 2 4 CPU Memory Map eem _ manes s m mowes mmes Tap meos OO HT vo uoowmurowm n Eur Docs OO Theory of Operation 2 Digital Section Detailed Circuit Description 2 29 Interrupt Controller The PLD U10 is the priority interrupt controller The interrupt controller reads incoming interrupts and interrupt control lines then encodes the highest priority interrupt into the interrupt level for the 68HC000 When the 68 000 responds to an interrupt request it asks the interrupt controller for an 8 bit vector that corresponds to the pending interrupt of the hig
233. e 792A correction as indicated in the formula Observe the default EXACT VALUE on the display It shows allowed number of decimal places for you to enter Enter your computation of MEAS in the 5790A using the keypad and press the ENTER key After you press ENTER the Control Display shows the progress of the internal process of the calibration step Note While a calibration step is in progress inaccurate values may appear on the Measurement Display This is normal When the 57904 is finished with the step the display will read accurately m When the step has completed set the 5700A to standby 7 Foran AC calibration point in the 60 mV through 600 mV group you will need to adjust the 5700A in accordance with the error displays that you recorded in Table 3 3 Proceed as follows a Obtain a copy of Figure 3 7 the worksheet for this group Fill in the voltage frequency 5700A error displays positive and negative from Table 3 3 and the associated 792A correction Press the DO Step softkey This automatically selects the appropriate 5790 range Calibration and Verification 3 Periodic Calibration Set the 792A INPUT RANGE knob to the appropriate position Always use the lowest range that will accept the input Caution Always ensure that the proper range has been selected before applying voltage to the 792A input Inputs that exceed the protection level shown on its rear panel label
234. e C 17 Group 2 70MV More DC Constants 70 mV Range Z 70MV foo Zero calibrated DC offset SHO_70MV foo Shunt input DC offset IA 70MV 0 0316228 Rough gain input to A D ratio Table C 18 Group AC 70 Flatness Constants 70 mV Range ET TIT m TT Te m F5 Te Appendices Calibration Constant Information Table C 19 Group DC 220MV DC Constants 220 mV Range DI 220MV Basic gain Ref DAC to input ratio OF 220MV foo Full scale calibrated DC offset Table C 20 Group ZC_220MV More DC Constants 220 mV Range 2 220 foo Zero calibrated DC offset SHO_220MV 00 Shunt input DC offset IA 220 Rough input to A D ratio Table C 21 Group AC 220MV Flatness Constants 220 mV Range Table 22 Group 700MV DC Constants 700 mV Range DI 700MV Basic gain Ref DAC to input ratio OF 700MV foo Full scale calibrated offset Table C 23 Group ZC_700MV More DC Constants 700 mV Range 2 700 00 Zero calibrated offset SHO_700MV 00 Shunt input DC offset IA 700MV 0 316228 Rough gain input to A D ratio Table C 24 Group 700 Flatness Constants 700 mV Range F3 TT TTE TT 5790 Table 25 Group 2 2 constants mV Range DI 2 2V Basic gain Ref DA
235. e Error Code 2107 421 Rear Panel Rear Panel DUART DUART internal loopback test e Error Code 2102 20 Main CPU Real Time Clock RTC running and valid date time e Error Code 2108 20 Main CPU Guard Crossing DUART DUART internal loopback test e Error Code 2106 21 Rear Panel IEEE488 GPIB interface chip e Error Code 2104 2 Display Output Display read write pattern test Error Code 2105 2 Display Control Display read write pattern test 5 3 17 Guard Crossing Processor Power Up Tests The following list identifies the test name and process associated with error codes for Guard Crossing Processor tests e Error Code 3500 417 Guard Crossing ROM checksum 16 bit CRC check e Error Code 3501 AI7 Guard Crossing RAM read write pattern test e Error Code 3503 17 Guard Crossing Watchdog test that watchdog goes off Error Code 3502 17 Guard Crossing DUART DUART internal loopback test e Error Code 3504 Hardware Initialization initialization test The hardware initialization test 15 indicates the success of resetting communication with U24 setting all the virtual registers to dormant values and setting some of the real hardware addresses to operational values 5 3 5790 Service Manual 5 4 5 4 5 5 System Startup Tests During power up the integrity of starting and maintaining a communication link with the Guard Crossing processor is done All the nonvolatile constants are checked for CRC errors
236. e supplies generated by the Digital Power Supply Table 2 2 Supplies Generated by the Digital Power Supply Signal Name Test Point UE Current Limit Rated Output 2 19 2 20 Rom we I 45 V Power Supply The unregulated 5 V supply uses CR25 CR28 in a full wave rectifier configuration with filter capacitors C12 C13 and C14 Other components in the circuit filter high frequency noise and provide a common mode choke Regulator U3 is fused by 3 15 A slow blow fuse F5 12 V Power Supplies Full wave rectifiers and filter capacitors generate the unregulated 12 V and 12 V supplies AC inputs are fused by F3 and both 2 A slow blow Three terminal 12 V and 12 V regulators U1 and U2 respectively are used Diodes protect the regulator from input shorts and from reverse voltage Inductors L3 L6 filter the regulated outputs Resistor R7 further isolates the 12 V FAN lines from the 12 V power lines The 12 V FAN and 12 V FAN lines power the two 24 V DC fans inside the 5790A 2 21 2 22 2 23 Theory of Operation 2 Digital Section Detailed Circuit Description 35 V Power Supply The 35 V power supply powers the grid drivers and the anode drivers on the front panel Measurement Display circuitry The 35 V supply is full wave rectified and regulated by Zener diodes VR14 VR15 and transistor Q5 The input 15 fused by 2 a 0 125 slow blow Components R5 and make up the current limiting ci
237. e than 5 from calibration temperature 2 gt capacitance approximately 100 pF Resolution and Range Limits Visits Wanqa Autorange Limits Resolution Upper Lower Filter Fast Filter Med Slow 2 2mV 2 2 mV 600 0 1 uV 0 1 uV 7 7 1 9 mV 0 1 uV 0 1 uV 22 22 6 mV 0 1 uV 0 1 uV 70 mV 70 mV 19 0 1 pV 0 1 uV 220 220 60 0 1 uV 0 1 uV 700 mV 700 mV 190 mV 1 0 uV 0 1 uV 2 2 2 2V 600 mV 1 0 0 1 uV 7V 7V 1 9 V 10 1 0 22 V 22 V 6v 10 uV 1 0 uV 70 V 70V 19V 100 uV 10 uV 220V 220V 60 V 100 uV 10 700 V 700 V 190 V 1 0 mv 100 uV 1000 V 1050 V 600 V 1 0 mV 100 uV 1 ln locked ranges readings be made approximately 1 beyond the autorange limits Introduction and Specifications More Secondary Performance and Operating Characteristics Maximum Non destructive Input Guard Isolation Volt Hertz Product Frequency Accuracy from 0 to 50 10 Hz 120 Hz Above 120 Hz acp te nt Frequency Reading Rate gt 200 Hz Maximum Settling Time to Full Specifications in Fiter 9 L200 HZ aana 2200 Filter SloW 200 Hz 2200 HZ cin etra e ie Filter Buffer Restart Limits Fine Fast 10 counts Medium Slow 2220
238. ear Panel and Front Panel assemblies This circuit buffers the 3 6864 MHz Clock with an inverter in U3 The circuit contains DC blocking capacitor C80 two stages of a low pass LC filter L80 and C81 L81 and C82 transformer T51 and termination resistor R82 CPU to Rear Panel Interface Components U25 U26 U27 and connector P220 interface the CPU to the rear panel Bi directional bus transceiver 026 buffers the data lines Signal R WR controls the transmission direction of the data lines and RRPNLEN is the IC enable The IC 025 2 38 2 39 2 40 2 41 Theory of Operation 2 Digital Section Detailed Circuit Description buffers control lines BRPDRTINT BRPIEEEINT and BRPDTK U27 enabled by buffers the address line A01 A05 and control lines WRL and R WR Control lines RESETL RPSEL TXDB RCVB and XMT go directly to connector P220 CPU to Front Panel Interface Components U25 U28 U29 U30 and connector P120 interface the front panel to the CPU Bi directional bus transceiver U30 buffers the data lines Control signal R WR controls the transmission direction of the data lines and FRNTPNLEN is the IC enable U28 enabled by FRNTPNLEN buffers address lines A05 A12 029 also enabled by FRNTPNLEN buffers address lines A01 A04 and control line R WR Two sections of U25 in parallel buffer IORESET providing twice the drive current of a single section generating BRESET Three o
239. echnique After you verify the 70 mV range apply each test voltage and frequency to both the verified range and the range under test Accept the reading on the verified range after showing that it is operating within specifications Step down through the ranges as described in the calibration procedures and shown in Figure 3 9 until the 2 2 mV range is verified On each range tested use the following formula and enter the results in Table 3 13 Note In the following formula AC VERIFIED RANGE ERROR PPM is previously determined error for the verified range at the frequency being tested AC UUT RANGE AC VERIFIED RANGE AC NOMINAL AC ERROR PPM x Q VERIFIED RANGE ERROR PPM 3 31 Verifying the Wideband AC Option Wideband verification is an optional test for those who want to verify that the 5790A WIDEBAND input requires Option 5790A 03 15 within tolerance There are two worksheets and one test record to facilitate this procedure You will need 1 copy of Table 3 14 8 copies of Table 3 15 one for each voltage range and 1 copy of the overall test record Table 3 16 3 53 5790 Service Manual VOLTAGE NOMINAL 5700A ERROR DISPLAY FROM TABLE 3 3 POSITIVE 5700A ERROR DISPLAY FROM TABLE 3 3 NEGATIVE 5790A READING DC 5790 ERROR 5790 2 5790 ERROR PPM NOMINAL elu046 eps Figure
240. ect INPUT1 or INPUT2 to use for Full DC calibration Then press this key eTe e gt La 4 La La 8 Press the INPUT1 key so that its keycap indicator is lit Press the Proceed With softkey The display changes to elu025 eps Cal Step Basic DC SKIP DO Step Step Range 2 2V Apply 2 0 DC a La 4 4 elu026 eps 3 15 5790 Service Manual 9 Set the 5700A to nominal than use knob to adjust for the error display you recorded in Table 3 3 Set the 5700 to operate When the U unsettled indicator on the 5700 goes out press the Step softkey The Control Display changes to Calibration Basic DC Apply 2 0 DC ENTER the exact value to do step Last Prev Voltage 2 000000 a La 10 At each step you accept default value pressing ENTER You this because you have already applied your correction in the adjusted 5700A setting The display tells you that the calibration step is in progress and informs you with a beep when the step is complete 11 When the 5790A completes the step the next DC step which requires 2 V DC is presented on the display Change the 5700A setting accordingly and do the calibration step as in the previous two steps Warning Some steps remainder of this procedure require application of
241. ed earlier in this step 3 Calculate the AC DC difference error as shown in Figure 3 15 or 3 16 Enter the result in the Table 3 13 3 48 Verification Calibration and Verification 3 3 28 Verifying Absolute AC Error for Region IV 70 mV through 700 mV Range You calculate absolute AC error by measuring the absolute AC of the source signal and comparing it to the AC measured by the 5790A Proceed as follows to verify absolute AC for Region IV 1 Use the setup in Figure 3 8 and the procedure under AC Calibration 2 Foreach point take the AC and DC measurements and enter them in Figure 3 17 To verify 5790 to its specifications the tolerance of calibration source must meet or exceed the tolerances shown in Table 3 13 Use characterized DC settings as follows Set the 5700A to nominal then use the knob to adjust for the error display recorded in Table 3 3 3 Calculate the absolute AC error as shown in Figure 3 17 Enter the result in Table 3 13 3 49 5790 Service Manual VOLTAGE NOMINAL FREQUENCY 5700A ERROR DISPLAY FROM TABLE 3 3 POSITIVE 5700A ERROR DISPLAY FROM TABLE 3 3 NEGATIVE 792A CORRECTION PPM DC DC 792 AC 792 DC AVERAGE rud 2 DC ERROR PPM 5790 5790 __ 792 792 10 792 CORR DC 5790 elu043 eps
242. er to reduce noise and ripple Switchable Active Low Pass Filter A five pole Bessel active filter attenuates low frequency ripple U24 pin 58 1 the input to the filter and pin 56 is the output Pins 59 and 60 connect to an internal op amp This op amp together with U3 C1 2 18 19 23 R23 38 33 40 and 41 comprise the filter Switches inside the A D IC can precharge C18 and 19 quickly to reduce the settling time A D Converter A proprietary Fluke IC U24 containing an A D converter and frequency Counter forms the basis for this circuit Voltage is measured through pins 3 14 15 16 18 or 23 The following list describes the U24 pin functions e Pin 14 is the diagnostic input Pin 15 is the divide by 6 input It measures larger voltages than the unity gain and X10 inputs but with the least resolution e Pin 18 is the unity gain input It measures voltages up to 3 V with less resolution than the X10 input but more resolution than the divide by 6 input e Pin 23 is the X10 input It measures voltage up to 32 m e Pins 28 through 35 comprise an output port that control the inputs to the instrumentation amp through 014 015 e Pins 36 and 37 connect to Y1 C15 and C16 to provide the clock for A D timing and serial interface communication e Pins 39 and 40 are the serial interface buffered by 025 pins 1 through 4 e Pins 45 through 50 together with C17 and Z1 pins 4 through 8 form the integrator for the dual s
243. erboard PCA cont 7 15 5790 ASLE 212 395 de 261 AS 281 22 291 OV ZL 6 12 OV ZL 0 S 2041 8 L ZL atl 22 OV S 901 S 56 25 SL os S 94 39 25 ov 8 61 54 INSTALLED HFBR1522 91 yF 2522 21 vee vez ASLT YEZ viz AZ val ASET val YSL YSL 2 OW l vol vet 12 OV i YZL YLL L vol 2 vs SE 2 SL ov GZ PSFAILINTR AS LT AZ L odds Ldda 69834 2044 7048 5944 9984 4 098 gv du 73594 gt vez 113545 viz 1 YRZ vec 1NI3331d49 571049 YLE HAOM BRESET 80Xl vee vi vv s ws 9 d4d YL YS 4 v6 Sadd yor 9994 YLL 443 YEL 1983 vel ZVdd Vee Ndd YSL 7943 2991 ver LWX 1 9744 voz viz Oivdi vzz vez viz
244. ess Error 90 90 Days Absolute Error Spec Absolute Error 228 2 2 1 Note You do not need to use the information in this column if you use the specified equipment and methods These are minimum use specifications that you can use for planning Wideband calibration or verification using alternate equipment and methods 1 Minimum use uncertainty relative to the 1 kHz point in this range 2 Minimum use uncertainty 229 2 2 1mV 230 2 2 mV 1mV 231 2 2 1mV 232 2 2 mV 1mV 233 2 2 mV 1mV 234 2 2 mV 1mV 235 2 2 mV 1mV 236 2 2 mV 1mV 237 2 2 mV 1mV 238 2 2 mV 1mV 239 2 2 mV 1mV 240 2 2 1mV 241 2 2 1mV 242 2 2 1mV 243 2 2 1 244 2 2 1 245 2 2 1 246 2 2 1 247 2 2 1 248 2 2 1 o c 6 tc lt i 3 64 Calibration and Verification 3 Verification Table 3 16a Wide Band Frequency Verification M 5790a Test 1 year easured Ranae Voltage V 9 4 N z wu T 1 Apply the test voltage into the 5790A wideband input and PM6666 counter The Measured Error is the deviation of the 5790A from the counter 3 32 Wideband 1 kHz Gain VerificatioN 7 2 2V 700 mV and 70 mV Ranges 1 Connect the equipment as shown in Figure 3 12 Set the HP 3458 to
245. etermined almost entirely by the ref amps To further reduce the effects of ambient temperature variations the hybrid is heated to a constant 62 C by the heater control circuitry on sheet 1 of the DAC schematic Temperature is sensed near the ref amps by a thermistor 1 If the substrate temperature changes the thermistor resistance changes This creates a correction voltage to the base of Q2 on the main board This in turn changes the power into the heater resistor screened on the back of the substrate as necessary to maintain a stable temperature Thermal runaway is prevented by a protection circuit Once the substrate temperature reaches approximately 67 C the change in the resistance of RT2 causes Q9 to turn on As transistor 09 turns it steals the base current from Q1 on the main board which brings it out of saturation This breaks the current path through the heater resistor This condition exists only if there is a failure Duty Cycle Control Circuit Refer to sheet 3 of the DAC schematic for the Cycle Control Circuitry DAC output voltages are represented in software by what are called as first and second channel counts Each count is a 16 bit number which is sent to the DAC Assembly via the guarded digital bus For example a first channel count of 20 000 in decimal represents a DAC output voltage of approximately 6 5 V half the reference voltage The first function of the duty cycle control circuitry is to c
246. etween 0 7 V and 2 2 V exactly a 10 dB range Input signals below 0 7 V are amplified as well as buffered As described under the previous heading high voltage divider outputs are in the range from 0 22 V to 22 V Amplifier A10A1 is a dual gain discrete surface mount assembly with 0 dB and 10 dB configurations For the 0 22 V 2 2 V 22 V 220 V and 1000 V ranges the gate of Q3 is high and the gate of Q2 is low configuring as a unity gain buffer For all of these ranges except the 0 22 V range and the 22 V range above 100 kHz the output of 10 1 falls between 0 7 V and 2 2 V and is connected directly to FTS U5 by relay K7 For the 70 mV 700 mV 7 V 70 V and 700 V ranges 1 is configured as a 10 dB amplifier by reversing the drive signals to Q2 and Q3 In these ranges except for the 70 mV range and the 7 V range above 100 kHz the output of is again between 0 7 V and 2 2 V and likewise connected to U5 through relay 7 For 70 mV and 220 mV ranges and the 7 V and 22 V ranges above 100 kHz an additional gain of 20 dB 15 needed to bring the input signal up to the 0 7 V to 2 2 V range required by 1 5 This is accomplished by switching the output of A10A1 into the input of 2 35 5790 Service Manual 2 36 2 81 2 82 A10A3 with U12 A10A3 is a 20 dB fixed gain amplifier similar in design to A10A1 Relay K7 is toggled to disconnect A10A1 and connect the output of A10A3 to the sensor
247. fier U2 pin 3 of 19 mV Amplifier U2 raises the signal level to 140 mV Resistor divider R35 and R25 reduce the signal by 6 dB to 70 mV and the signal passes to the RMS sensor amplifier input Q6 and U5 through FET Q17 22 mV 7 mV and 2 2 mV ranges These are obtained by switching out the attenuator sections of resistor network 74 in 10 dB steps down to zero attenuation in the 2 2 mV range 2 108 DC Offset Feedback for Amplifier U3 Lower Ranges Amplifier U10 and associated parts provide a DC feedback loop to keep the DC voltage at the output of amplifier U3 pin 6 near zero The DC is sensed by resistor R68 amplified by U10 and feedback to FET pair Q3 at pin 6 The loop adjusts the voltage at Q3 pin 6 until the amplifier output DC voltage is near zero The transistors Q19 Q20 Q21 and Q22 in the sources of the dual FETS Q3 and Q6 are used to set the bias current to approximately 10 mA in each transistor and provide temperature compensation for the transconductance of the FETS As the temperature increases the base emitter voltage of the transistors decreases and the current increases to keep the voltage between the base and the 6 V supply constant The increased current compensates for the decrease in the FET transconductance as the temperature increases 2 109 RMS Sensor Circuit Buffer amplifier U5 amplifies the scaled inputs to 1 2 V RMS and passes the signal through the protection diode bridge CR16 through CR19 and to RMS
248. filament driver circuitry consists of transistors Q1 through Q and zener diodes VR1 and VR2 with associated resistors The transistors are driven by 7406 open collector drivers U13B and U13A These drivers are controlled by AOUT and BOUT AOUT and BOUT are synchronous non overlapping three eighths duty cycle 57 6 kHz timing signals generated by U3 Each signal is alternately active high for 6 51 us with a dead time between active signals of about 2 17 Us to allow the turn off times of the drive transistors When AOUT is high U13B turns Q2 and Q4 on Q4 turns Q6 on providing a path for the filament current through Q2 and Q6 Zener diode VR2 provides the DC voltage offset necessary for proper filament operation Then when BOUT is high U13A turns Q1 and Q3 on Q1 turns Q5 on providing a path for the filament current through Q3 and Q5 effectively reversing the direction of the voltage driving the filament Zener diode provides the DC voltage offset necessary for proper filament operation PLD U4 also generates the 225 Hz square wave SCAN signal used by PLD U9 to control front panel keypad scanning and key debounce Dual port RAM 01 contains all the Control Display data written by 68HC000 microprocessor on the CPU board PLD U4 contains 10 bit address counter which is used U4 to read the contents of U1 U1 provides BUSYD signal to U3 which is active low whenever the CPU and UA try to access the same RAM location at the same
249. for Absolute AC Error 70 mV through 700 mV Ranges Worksheet for DC Error 2 2 V through 1000 V Ranges Wideband Verification Test Setup Accessing the Air Filter eene ener nennen enne nnne Rear Panel u ht eder Rear Panel Assembly Front Panel Removal o ene Analog and Digital 5790 ON LR 30 SION A S D NN m 21 Rear Panel 2 4 4 1 1 1 1 4 2 1 KAE yaa atus Final Assembly E 6 8 Final Assembly 6 13 A62 Input Block Assembly raag anat Erra 6 16 Al Keyboard v 6 18 A2 Front Panel 2592 UD EROR 6 21 Analog Motherboard nnn 6 23 A4 Digital Motherboard PCA 6 26 AG Wideband PCA Option 203 6 31 RMS Support
250. for the 70 mV range Generates flatness calibration data for the 22 mV range Generates flatness calibration data for the 7 mV range Generates flatness calibration data for the 2 2 mV range 1 These uncertainities can be achieved using the bootstrap techniques described in the AC calibration procedure Calibration and Verification 3 Periodic Calibration 3 17 AC Calibration Table 3 6 lists the equipment required to perform the AC calibration of the main input Before you begin make 12 copies of Figure 3 6 and 10 copies of Figure 3 7 Those are worksheets to help you calibrate the various AC points Table 3 6 Equipment Required for 5790A Main Input AC Calibration Required Equipment Manufacturer and Model AC DC Transfer Standard Fluke 792A with 60 mV to 1000 Vrms 10 Hz to 1 MHz accessories Multifunction Calibrator Fluke 5700A 2 mV to 1000 Vrms 10 Hz to 1 MHz Amplifier for Above Fluke 5725A higher Volt 600V to 1000 Vrms 10 kHz to 100 Hertz product kHz 8 1 2 Digit Precision DMM Hewlett Packard 3458A 0 2VDC 10 nV resolution 1 ppm linearity 50Q Tee Male Fluke P N 912605 or Stainless Steel type recommended Male Male equivalent 50Q Type N Female to Pomona Model 1740 or 1000 Vrms Breakdown Voltage Double Banana Plug equivalent minimum Adapter PM6666 5ppm Frequency Uncertainty or Better Binding Posts to 5002 Type Pomona Model 1796 or 1000 Vrms Breakdown Voltage M
251. g Q7 and Q8 off The 75 V and 35 V constant current sources can then supply the appropriate zener diodes and drive the bases of the respective emitter followers When a display refresh fault occurs the 75VSD line on P119 pin 5C coming from Front Panel assembly goes high This signal pulled up by R4 drives the base of Q10 through base resistor R11 Transistor Q10 then pulls the base of Q9 near ground turning 09 off On power up or during a CPU reset the RESETL signal is low pulling the base of Q9 near ground through R9 also turning Q9 off Resistor R12 15 a turn off resistor for Q9 Diodes CR31 and CR33 are in a wired OR configuration When Q9 is saturated CR31 and CR33 pull their respective junctions to CR32 and CR34 near ground turning Q7 and Q8 off When Q9 is off the junctions are pulled high through R8 and R10 saturating Q7 and Q8 on When on Q7 removes the base drive from Q3 shutting down the 75 V supply Similarly Q8 removes the base drive from Q5 shutting down the 35 V supply Diodes CR32 and CR34 simply ensure that Q7 and Q8 are off when Q9 is on Resistor R8 guarantees that Q7 will hold the 75 V supply off until it drops below 15 6 V and R10 holds the 35 V supply off to 7 8 V 2 13 5790 Service Manual 2 24 2 25 CPU Assembly A20 The CPU Central Processing Unit for the 5790A 15 single board computer based on a 68HC000 microprocessor Figure 2 4 is a block diagram of the CPU asse
252. g frequencies of a variable Drift Gradual change in a value over time Error Deviation from correct value The different types of error defined in this glossary are floor gain offset linearity random scale systematic transfer and zero 5790 Flatness A measure of output level variation for an voltage source as frequency is varied Flatness limits are normally specified as a ratio to nominal output level at a reference frequency Floor Error A contribution to measurement or source uncertainty that is independent of reading or output setting In uncertainty specifications floor error is often combined with fixed range errors and expressed in units such as microvolts or counts of the least significant digit Also see error Full Scale The upper limit of measurement or source value for which a given uncertainty specification applies including any overrange Also see overrange and range Gain Error Same as scale error An example of scale or gain error is when the slope of a calibrator s displayed output vs its true output is not extly 1 A calibrator with only gain error no offset or linearity error will read 0 V with 0 V on the display but something other than 10 V with 10 V on the display Ground The voltage reference point in a circuit Earth ground 15 a connection through a ground rod or other conductor to the earth usually cessible through the gro
253. g the voltage to the 792A input Inputs that exceed the protection level shown on its rear panel label disrupt the state of calibration and can cause instrument damage Set 5700 to nominal test voltage DC positive Do not use characterized setting as the 5790 15 now used as the DC reference thus allowing for any resistive drop caused by the 792A loading Wait for the 5700 U annunciator to go out Wait for 30 seconds for the DMM reading to stabilize Record the DMM reading under the 792A column in the worksheet for DC Record the reading on the 5790A Output Display under the 5790A column for Press ENTER on the 57004 to toggle output polarity Again allow the DMM reading to stabilize Record the DMM reading under the 792A column in the worksheet for DC Record the reading on the 5790A Output Display under the 5790A column for DC Ignore polarity for the 5790A reading Record the absolute value Apply the frequency required for the calibration step Wait for the U annunciator on the 5700A to go out Allow the DMM reading to stabilize Record the DMM reading under the 792A column in the worksheet for Do not record a reading for the 5790A Now do a computation to get the measured AC using the formulas shown in the worksheet 1 Compute the average of the DC readings for the 5790A and the 792A as shown 2 Compute MEAS using the formula shown Be sure to include th
254. grammed from latch U21 pin 19 is momentarily set low to reset the U27 latch Also PC4 is programmed low by U26 pin 15 and the circuit 15 back to normal operation 9 199 99 13 23 142 92 139 139 1139099 09 99 43 HA b2 b2 LS LA D RRR RR RR RF XO Lh SUS D DJ Chapter 3 Calibration and Verification Tint T T nts Calibration oie retten oe ER ie Periodic and Service Calibration Full or Range Calibration seen Automating Calibration and Verification How Calibration Memory is Organized How to Use the Calibration Menus The Menu utes HERE Zero Cal Softkey eiie aooe tanaoa See Cal Dates Softkey onres i aR Cal Reports Softlkey aa aaa Update Cal Dates Periodic Calibrating the Main Characterizing the DC Source DC Calibr ti hz
255. gulator U8 with heat sink bypass capacitors C20 and C69 and protection diodes CR14 and CR16 LH COM is the return path The 5 LH supply uses the unregulated 5 LHR from the Filter assembly and consists of three terminal TO 220 regulator U12 bypass capacitors C23 and C24 and protection diodes CR21 and CR24 RLH COM is the return path Capacitors C20 C23 C69 C70 and C24 improve the stability and provide filtering for U8 U11 and U12 respectively Diodes CR14 CR17 and CR24 protect the regulators from input shorts Diodes CR16 CR20 and CR21 protect the regulators from reverse voltage Regulated 17 S Supplies S COM is the return path for the 17 S and 17 S supplies S COM is also connected to LH COM These signal lines can be found on the Motherboard and the Regulator Guard Crossing assembly The 17 S supply uses the unregulated 17 SR supply from the Filter assembly This supply uses three terminal TO 3 regulator U6 with heat sink and R5 and R6 The output voltage 1s set by the resistors R5 and R6 Capacitors C9 and C67 are for bypass Capacitor C11 improves ripple rejection Diode CRS protects the regulator against shorts at the input while CR11 and CR26 protect the regulated output from the reverse voltage The 17 S supply uses the unregulated 17 SR supply from the Filter assembly It uses three terminal TO 3 regulator U7 with heat sink and R10 and R11 The output voltage is set by the resistors R10 and R11 Capacitors C
256. hest priority The interrupt controller responds with the 4 LSBs of the vector according to how it is programmed The 4 MSBs are pulled up on resistor network 71 2 5 shows the interrupts their priority levels and vectors Table 2 5 CPU Interrupts Priorities and Vectors mam s IR em s mur sma enn T _ ws ewe s s er 2 830 Glue Logic The ICs U2 U3 and U9 form the glue logic circuit which keeps various CPU functions running properly The four OR gates in U9 and an inverter in U3 use control signals UDS LDS and from the microprocessor to generate control signals WRL and RDU 2 31 RAM Random Access Memory Random access memory is contained in three pairs of sockets U19 and U20 U21 and U22 040 and 041 These sockets accommodate either 32 K X 8 or 128 K X 8 static CMOS RAM modules 32 KB or 128 KB each The 5790 is shipped with U19 U22 installed using 32 K X 8 parts and providing 128 KB of static RAM 2 32 Read Only Memory Read only memory is contained in three pairs of sockets U15 U16 U17 U18 and U23 U24 These sockets accommodate 27010 EPROMS 128 K X 8 devices 128 KB each The jumpers allow 256 KB devices to be used in their place The 5790 is shipped with 015 018 installed providing 512 KB of EP
257. ibration Throughout the DC and AC calibration the Control Display prompts you with the next step and informs you about the progress of calibration The number of calibration steps depends on whether the CALIBRATION MODE switch is set to PERIODIC or SERVICE The cable connections for the DC and AC calibration are kept as similar as possible so that a minimum number of mechanical changes are required during the procedure 3 15 Characterizing the DC Source To meet the test uncertainty requirements for 5790A main input DC calibration you must first characterize 1 e calibrate to a higher uncertainty than the published specifications the DC function of the 5700 at the required points Table 3 1 lists the equipment required for DC source characterization Tables 3 2 and 3 3 comprise the test record in which you will record the results of the following procedure Make a photocopy of these two tables before you proceed Table 3 1 Equipment Required for 5790A DC Characterization Equipment Manufacturer and Model Minimum Use Specifications Multifunction Calibrator to Characterize for 5790A DC Fluke 5700 calibration DC Voltage Calibrator Fluke 5440B V DC snort tern stability better than 1 ppm 1 uV resolution Kelvin Varley Divider Fluke 720A 0 1 ppm 0 1 ppm terminal linearity 0 1 ppm terminal linearity 0 1000 V short term stability better 1 Uncertainty 0 5 ppm 100 1 Reference
258. icate a possible fault on the A15 A D Amplifier assembly Check the Null DAC reference and Null DAC output through the instrumentation amplifier input switching then through the instrumentation amplifier to the A D chip U24 inputs Test Step ADDAC A D DAC Output Tests the DAC DAC to DIVOUT and DAC to DIVOUTS outputs on A D Amplifier assembly This test proceeds as follows l Connect DACHI to positive and negative inputs of instrumentation amplifier Program DAC to output 0 0 Measure with x1 A D range Connect DACHI to positive and negative inputs of instrumentation amplifier Program DAC to output 2 0 Measure with x1 A D range Connect DACHI to positive input of instrumentation amplifier minus input to RCOM Program DAC to output 0 1 0 and 2 0 Measure with x1 A D range Connect RCOM to positive input of instrumentation amplifier minus input to DIVOUT Connect DACHI to DIVOUT Program DAC to output 1 0 Measure with x1 A D range Connect DACHI divided by 5 to DIVOUT Program DAC to output 10 0 Measure with x1 A D range Troubleshooting Introduction Possible errors include Error Code 3006 A15 A D DAC DACHI 0 0 Failed Error Code 3006 A15 A D DAC DACHI 2 0 Failed Error Code 3006 A15 A D DAC DIVOUT 1 0 Failed Error Code 3006 A15 A D DAC DIVOUT5 2 0 Failed elu060 eps These errors indicate a possible fault on the A15 A D Amplifier assembly or the A16 DAC assembly Check the A16 DAC output to 15 A D Am
259. igh voltage output devices U4 also controls the grid timing and display refresh Kk kk k k k kk Fek k ke F k ke e k kk k kk kk k k k B D G4 G5 G6 EEE EEEE 006 Adjacent columns in adjacent grids driven while opposite columns are turned off For instance grid G4 contains columns B and C and grid G5 contains columns D and A 2 44 Theory of Operation Digital Section Detailed Circuit Description G4 and G5 are driven simultaneously while anode columns G4 C and G5 D are activated and G4 B and G5 A are driven off Next grids G5 and G are driven simultaneously while columns G5 A and G6 B are activated and G5 D and G6 C are driven off This pattern 15 repeated for all 128 grids at a refresh rate of about 75 Hz Both the A and C U16 and U18 and B and D U17 and U19 anode drivers input registers are latched with the same data while the output drivers are appropriately enabled and displaying the data previously strobed to the driver outputs from the input registers The input register data 15 strobed to the output drivers while all of the drivers are disabled or blanked Following this either the A and B drivers are enabled to display the A B data when the C and D drivers latched with A B data are disabled or the C and D drivers are enabled to display the C D data when the A and B drivers latched with C D data are disabled Control Display
260. ight to indicate which input is selected and to indicate when external trigger mode EX TRIG or external guard EX GRD is selected Theory of Operation 2 Digital Section Detailed Circuit Description Latch U10 is controlled by the LED LATCH signal from the decoding PLD U3 Signal LED LATCH latches the CPU data bus into the internal latches of U10 write to the front panel LED memory space This data appears at the output when control line LEDENABLE goes low Control line LED OUTPUT CNTRL from U3 is inverted to create LEDENABLE Table 2 7 shows which line activates each LED Table 2 7 Control Lines for the Keyboard LEDs INPUT 2 LED1A EX GRD LED2A 2 A7 Keyboard Assembly A1 The Keyboard assembly provides the operator with front panel control of the 5790A It connects to the Front Panel assembly A2 through a cable and includes an elastomeric keypad and six keycap LEDs The elastomeric keypad and the printed circuit board form a 45 switch keyboard arranged in eight columns and six rows only 32 of these keys are used The keyboard scanner circuit on the Front Panel assembly sequentially drives columns one through eight When a key is pressed a low appears on the corresponding row as the key s column is scanned The keyboard scanner circuit encodes the key s row and the column location then takes appropriate action The six keycap LEDs through CR6 are controlled by the LED driver circuit
261. ing 5 elu049 eps Printed circuit assemblies only need cleaning after repair work After soldering on a pca remove flux residue using isopropyl alcohol and a cotton swab 4 5 4 8 Maintenance 4 Access Procedures Access Procedures Warning Servicing described this chapter is to performed qualified service personnel only To avoid electrical shock do not perform any servicing unless qualified to do so Top and Bottom Covers Check that power is not connected to 5790 the power control must be off and line power cord must be disconnected Top and bottom covers are each secured with eight Phillips head screws four front four rear Digital Section Cover The Digital Section is accessed through one top cover that 15 secured by six Phillips head screws Analog Section Covers The Analog Section is enclosed with separate covers on top and bottom The top cover is secured with six Phillips head screws The bottom Analog Section cover is secured with eight Phillips head screws three short five longer Rear Panel Removal and Installation Detach the Rear Panel by removing the six hex head screws three on each rear handle side and the two Phillips head screws found along the side of the Fan Assembly Refer to Figure 4 2 for screw locations REMOVE y Es Blo 74 Rs z
262. ing within specifications For this procedure you set the rear panel CALIBRATION MODE switch to PERIODIC Service calibration 15 a more complex calibration procedure that is required only after hardware repair or replacement Service calibration 15 similar to the procedure done at the factory when the 57904 is built For this procedure set the rear panel CALIBRATION MODE switch to SERVICE This switch setting adds many calibration points to the software controlled calibration routine The CALIBRATION MODE switch setting has no effect on WIDEBAND input option calibration or verification 3 4 Full or Range Calibration When you perform a periodic calibration of the main input you calibrate the DC measurement function first because subsequent AC calibration relies on 5790 DC measurement accuracy Calibrating both the DC and AC functions is called full calibration Instead of full calibration you can select the range calibration which presents display prompts for calibrating the DC or AC functions of a single input range This allows you to repeat portions of a just completed calibration You can use the Skip Step softkey to redo one or a few points leaving the rest of the calibration points unchanged Once you press a range cal softkey you proceed with the calibration steps exactly as explained under Calibrating the Main Input or Calibrating the WIDEBAND Input heading 3 5 Automating Calibration and Verification Fluke uses
263. inute stability better than 50 ppm Calibrates the relative frequency response of INPUT 1 and INPUT 2 through the protection circuit calibrates timebase 10 ppm or better accuracy Generates a correction 18 18 1 and 1 minute stability better than 50 ppm for thermal sensor non linearity at low V and f Generates flatness calibration data for the 1000 V range Generates flatness calibration data for the 1000 V range Generates flatness calibration data for the 220 V range 130 3 37 5790 3 38 70 V AC 1 kHz 70 V AC 20 kHz 70 V AC 500 kHz 70 V AC 1 MHz 22 V AC 1 kHz 22 V AC 20 kHz 22 V AC 100 kHz 22 V AC 300 kHz 22 V AC 500 kHz 22 V AC 1 MHz 7 V AC 1 kHz 7 V AC 20 kHz 7 V AC 100 kHz 7 V AC 300 kHz 7 V AC 500 kHz 7 V AC 800 kHz 7 V AC 1 MHz 2 2 V AC 10 Hz 2 2 V AC 1 kHz 2 2 V AC 20 kHz 2 2 V AC 300 kHz 2 2 V AC 1 MHz 700 mV AC 10 Hz 700 mV AC 1 kHz 700 mV AC 20 kHz 700 mV AC 300 kHz 700 mV AC 1 MHz 220 mV AC 10 Hz 220 mV AC 1 kHz 220 mV AC 20 kHz 220 mV AC 300 kHz 220 mV AC 1 MHz Voltage to Apply 60 V RMS 1 kHz 60 V RMS 20 kHz 20 V RMS 500 kHz 20 V RMS 1 MHz 20 V RMS 1 kHz 20 V RMS 20 kHz 20 V RMS 100 kHz 20 V RMS 300 kHz 20 V RMS 500 kHz 20 V RMS 1 MHz 6 V RMS 1 kHz 6 V RMS 20 kHz 6 V RMS 100 kHz 6 V RMS 300 kHz 6 V RMS 500 kHz 6 V RMS 800 kHz 6 V RMS 1 MHz 2 V RMS 10 Hz 2 V RMS
264. ion manuals 3 Connect the equipment as shown in Figure 3 2 5440B oO b OO 732 1 845A 720 Qo O O OO T q p elu017 eps Figure 3 2 DC Source Characterization Setup Part 1 Note If the 845A is not grounded through the power cord a connection must be made to the 5440B ground as shown 4 Setthe ratio dials ofthe 720A to represent the certified value of the 732A For example 10 000123 V becomes 1 0000123 on the 720A 5 Set 845 to the 30 mV range and OPR ZERO switch to ZERO 6 Setthe 5440B to 11 V OPERATE Set the 845A OPR ZERO switch to OPR reducing the range switch until the largest on scale reading is obtained Edit the 5440B output until a null is indicated on the 845A Again reduce the range switch setting until the largest on scale reading is obtained editing the 5440B output for a null Repeat this procedure until you obtain a null of 1 Set the 845A OPR ZERO switch to ZERO The 5440B 720A combination is now calibrated in absolute voltage relative to the 732A Note For the remainder of this procedure the 57004 EXT GUARD must be selected keycap LED lit and the strap between V GUARD and GROUND must be removed 3 9 5790 Service Manual Whenever EXT Guard is activated the green indicator on the EX
265. ip status There should be an overload indication The error from this test 1s Error Code 3010 A10 Transfer Overload Check Failed elu063 eps S16 Troubleshooting Introduction This error indicates a fault in the overload circuitry on 10 Transfer assembly The overload interrupt should toggle on and off at a slow rate as the overload detection circuitry detects sensor overheating and clamps the sensor input When the sensor cools down the clamp circuitry releases Check that indicated DAC voltage is at sensor input Test Step ZEROS Test bottom three ranges front end amplifier zeros The test proceeds as follows 1 Configure instrument in 2 2 mV range with no input use relay in front of protection SIP to short input to ground Measure input of sensor 2 Configure instrument in 7 mV range with no input use relay in front of protection SIP to short input to ground Measure input of sensor 3 Configure instrument in 22 mV range with no input use relay in front of protection SIP to short input to ground Measure input of sensor Possible errors include Error Code 3012 A10 Transfer 2 2 mV Range Zero Failed Error Code 3012 A10 Transfer 22 mV Range Zero Failed Error Code 3012 A10 Transfer 7 mV Range Zero Failed elu064 eps These errors indicate a fault on A10 Transfer assembly Trace from short to ground through the amplifiers to the input of the RMS sensor Test Step DIVIDERS Input Dividers Tests tha
266. l 5790A o lt o N 10 Figure 6 8 1 RMS Support 6 34 List of Replacable Parts 6 Parts Lists Table 6 10 A6A2 WB Input Protection PCA SN Part emer me e pememmowwanremm ps war esewmemiew owe eum wes i _ 346916 39 BULK RESISTOR A52R RES MF 10K 1 0 125W 100PPM R12 R15 L ma s RESISTOR A52R RES CF 130 5 0 25W 2 s RESISTOR A52R RES CF 470 5 0 25W 2 mr O RESISTOR A52R RES CF 1 8M 5 0 25W 1 6 35 5790 5790 1697 Figure 6 9 2 WB Input Protection 6 36 List of Replacable Parts 6 Parts Lists Table 6 11 A10 Transfer PCA Description Qty Notes 893300 1 4 893305 1 4 893313 1 4 820548 1 CAPACITOR ROSA CAP POLYES 1UF 10 50V 733089 1 CAPACITOR RO5R CAP CER 100PF 20 50V COG 721605 1 C4 C9 C21 CAPACITOR FILM POLYESTER 0 1UF 10 50V 5MM 649913 29 C24 28 LS RADIAL TAPE C101 108 112 113 116 117 130 132 140 143 150 151 CAPACITOR CAP CER 120PF 5 100V COG 543819 1 1 PRECISION AMPLIFIER A2 HIGH VOLTAGE PROTECTION PCA A3 5790A 7695 ASSEMBLY HIGH GAIN PRECISION AMP C1 CAPACITOR RO5A CAP POLYES 0 047UF
267. l Converter will not stabilize in a drafty or unstable environment In this procedure you will fill in the 5700A ERROR column of Table 3 8 for later use during the WIDEBAND flatness calibration Note Fluke offers a calibration service for NARDA Model 777C attenuators at the Everett Service Center For price and delivery of this calibration service please call the Everett Service Center at 206 356 5560 1 Connect equipment as shown in Figure 3 10 Make sure that all connections are tight The A55 must be loaded with 50 by connecting it as shown the figure or it will be destroyed when the voltage is applied 3 29 5790 Service Manual 8506A DMM COMPUTER TERMINAL FOR SERVICE CAL ONLY RS 232 3V a NO CABLES 5700A CALIBRATOR 5790A WIDEBAND A A WIDEBAND OUTPUT m INPUT GR374T ATTEN ATTEN 3 30 10 11 12 elu035 eps Figure 3 10 Wideband Calibration Source Characterization Part 1 Make sure equipment warmup requirements are met Lock the 5790A on the 220 mV range Set the 5700A to output 3 2 V at 1 kHz The 5790A will read approximately 100 mV and the 3 V A55 output will be about 7 mV Allow the A55 to stabilize then press the STORE and OFFSET keys on the 8506 DMM Press the SET REF softkey on the
268. ld be removed when the AC measurements are being made Alternatively you can determine DC errors and AC DC errors independently then combine them This 15 the procedure presented here In this case you take the measurements and make calculations in the same way as Regions I and III to obtain the AC DC errors You may have already calculated these errors if you are verifying both the AC DC and the absolute AC performance of the Calibration and Verification 3 Verification instrument You then take DC measurements and calculate DC errors Combine the errors to obtain absolute AC error Proceed as follows to use the error combination method 1 To determine the DC errors connect the test equipment as shown in Figure 3 5 2 Usecharacterized 5700A DC settings as follows Set the 5700A to nominal than use the knob to adjust for the error display you recorded in Table 3 3 Take dual polarity DC readings and record them in Figure 3 18 To verify the 5790 to its specifications the tolerance of the DC source must meet or exceed the tolerances shown in Table 3 10 3 Calculate the DC error as shown in Figure 3 18 4 Combine the DC errors and the AC DC errors using the following equation to obtain the absolute AC reading error and enter the result in Table 3 13 AC READING ERROR DC ERROR AC DC ERROR 3 30 Verifying Absolute AC Error for Region V 2 2 mV through 22 mV For the 7 mV through the 22 mV ranges use a bootstrapping t
269. le on sheet 1 of the Rear Panel schematic 2 12 Hear Panel Digital Control The Rear Panel decodes address lines from the bus connected to the main CPU through the connector J121 Decoding is accomplished with C22V10 PLD U8 2 13 Clock Regeneration Circuit In order to minimize EMI electro magnetic interference inside the 5790A chassis the rear panel accepts a low level 200 mV sine wave 3 68 MHz clock from the CPU assembly and conditions it to proper TTL clock levels This is done by a differential amplifier U18 which amplifies the incoming signals 3 6864MHZCLK and 3 6864MHZCLK The output of U18 is a TTL level 3 68 MHz clock called RP3 68 MHZ that is buffered by PLD US creating RPCLK for use by DUART dual universal asynchronous receiver transmitter U5 and IEEE interface IC U2 2 14 IEEE 488 GPIB Interface The IEEE 488 GPIB interface circuit provides the interface between the IEEE 488 connector J1 and the 5790A processor on the CPU A20 assembly The circuitry uses a TMS9914 U2 General Purpose Interface Bus GPIB adapter to meet the requirements for talker listener operation on the IEEE 488 bus This circuit translates asynchronous 8 bit data and control information under control of an external controller and converts this information to an acceptable format for the CPU The 9914 has internal circuitry which handshakes in the proper GPIB protocol and stores data in an internal buffer This IC also ha
270. lists the equipment required to calibrate the WIDEBAND input Before you proceed make a copy of Table 3 8 which is the worksheet for WIDEBAND input calibration 3 27 5790 Table 3 7 Equipment Required for Wideband Calibration Required Equipment Manufacturer and Model Minimum use Requirements Fluke 5700 with Wideband 03 3 2 Vrms 10 Hz 30 MHz Option incl Cable and 500 term 32 mV 3 2 Vrms 1 kHz 3 Vrms 10 Hz 30 Thermal Voltage Converter Fluke A55 3V 2 5 0 01 0 20 6 absolute uncertainty 874 TL Coaxial Tee Locking Fluke P N 157248 or equivalent Compatible with A55 input connector 874 QNJL Adapter Type Gilbert Engineering 0874 9711 or Facilitate connection of Wideband F to 874 locking equivalent output cable to 874 Tee 874 QNPL Adapter Type Gilbert Engineering 0874 9811 or Facilitate connection of attenuators to N M to 874 locking equivalent 874 Tee 32 mV 3 2 Vrms 1 kHz 0 01 96 8 1 2 Digit Precision DMM Hewlett Packard 3458A Uncertainty 0 7 mVDC 20 nV short term stability 500 Type N Tee Male Functional Stainless Steel type Male Male Fluke P N 912605 or equivalent recommended 20 dB type N RF Attenuator 0 0001dB dB C Temperature 8 each JFW Industries 5OHFI 020N Coefficient 500 0 50 DC Resistance 10 dB type RF Attenuator 0 0001dB dB C Temperature 1 each JFW Industries 5OHFI 010N Coefficient 500 0 5
271. llation 4 8 Hybrid Cover Removal 4 9 Installing a Wideband AC Module Option 03 4 9 Clearing Ghost Images from the Control Display 4 10 Replacing the Clock Calendar Backup Battery 4 11 Using Remote Commands Reserved for Servicing 4 11 Using the FATALITY and FATALCLR Commands 4 11 ST Em 4 1 5790 4 2 Maintenance 4 Introduction 4 1 Introduction This chapter covers procedures that do not fall the category of troubleshooting or repair This includes access procedures Installation of the Wideband module Option 03 pertodic cleaning and other special service procedures 4 2 Cleaning the Air Filter Caution Damage caused by overheating may occur if the area around the fan is restricted the intake air is too warm or the air filter becomes clogged The filter must be removed and cleaned every 30 days or more frequently if the 5790A 15 operated in a dusty environment The air filter 15 accessible from panel To clean the atr filter refer to Figure 4 1 and proceed as follows 1 Remove filter element a Unscrew the knurled screw at the top of the air filter counterclockwise b Pullthe air filter retainer downward it hinges at the bottom Remove the filter element 2 Clea
272. lope A D Converter e Pins 51 and 52 connect to 1 V reference as described under Null DAC 2 95 2 96 2 97 Theory of Operation 2 Analog Section Detailed Description Frequency Counter Low Pass Filter The Fluke A D IC U24 contains the frequency counter Frequency is measured through pin 3 If the input signal is DC its polarity is determined through this input The low pass filter R31 and 24 15 switched in the frequency measurement line only to filter out high frequency noise Transistor Q5 and R44 switch 41 parallel with C24 for additional filtering for low level Input voltages at low frequencies Digital Control and Power Supply An 82 55 peripheral interface IC U26 latches in digital control signals A UCN5801 power driver U27 controls relays K1 and K2 The power supply for the A D Amplifier is comprised of the following components and circuits e Resistors and 6 and 5 provide 8 V supplies for U9 Resistor R5 and VR1 provide a 5 V floating supply for ICs U8 and 13 Resistor R48 and regulator VR7 supply 15 V for U16 Capacitors C7 8 12 28 through 39 50 through 55 62 through 64 and 67 through 70 bypass the power rails DAC Assembly A16 The DAC digital to analog converter provides a digitally adjustable precision DC voltage from 0 to 11 V The DAC contains four assemblies DAC Main Board A16 DAC Filter SIP A16A1 Reference Hybrid
273. m Checksum 8 30 91 6 34 12 Fault 4301 Rom Checksum 8 30 91 6 34 13 Fault 4301 Rom Checksum 8 30 91 6 34 14 Fault 4301 Rom Checksum 8 30 91 6 34 15 Fault 4301 Rom Checksum 8 30 91 6 34 16 Fault 4301 Rom Checksum 5790 Service Manual FATALCLR Clears the list of the fatal faults logged since the list was last cleared by the FATALCLR command The list is read by the FATALITY query Sequential command Parameter None 4 23 Error Codes The 5790A error codes are listed below 0 ERR No errors 1 ERR Error queue is full 100 CAL Invalid procedure number 101 CAL No such step in procedure 102 CAL No Cal Diag procedure underway 103 CAL Cal Diag halted 104 CAL step to which to back up 105 CAL such position range under 106 CAL such range procedure 107 CAL External DAC calibration failed 108 CAL Entered reference outside of limits 109 CAL Measured entered input don t match 110 CAL Frequency doesn t match expected 111 Input is of wrong polarity 112 CAL Input is changing during call 113 CAL Input tripped protection circuit 114 CAL Constant 905 out of limits 115 CAL Flatness constant out of limits 116 CAL Range gain constant out of limits 117 CAL f Rough gain constant out of limits 118 CAL Offset constant out of limits 119 CAL Low constant out of limits 120 CAL s range Zero out of limits 121 CAL s range shunt
274. mbly The CPU assembly communicates with the Guarded Digital section the Front Panel assembly and the Rear Panel assembly The board can be divided into three primary areas The microprocessor and its support circuitry Memory Peripheral ICs and I O interfaces Microprocessor support circuitry consists of a power up and reset circuit clock generation a watchdog timer address decoders and DTACK data acknowledge generator bus error timeout and interrupt controller Power Up and Reset Circuit The power up and the reset circuitry consists of line monitor IC U1 C5 C6 R3 Z3 switch SW1 and inverters U2 This circuit provides 195 ms reset pulse at power up or upon pressing and releasing SW1 placing the CPU assembly in a known safe condition If the power supply glitches or falls below 4 55 V 0 05 V U1 resets the 5790A The reset pulse duration is determined by C5 Note that SW1 performs a different function than the front panel RESET button SW1 is a hardware reset that is hard wired to and directly read by the microprocessor The front panel RESET button is a software reset it tells the system software to restore the 5790A configuration to a default condition The heart of this circuit is the line monitor IC U1 On power up or when SW1 is pushed UI forces an active low reset pulse on RESETL and active high pulse on RESET RESETL helps to prevent the accidental writes to EEPROM and drives an inverter in U
275. mens wer eemeeeemmemm H e eese 223 umar mr R1 R3 RESISTOR SMR RES CERM 470 5 125W 200PPM 1206 74056 2 C H C ee R5 RESISTOR CERMET 1 8K 5 0 25W 200PPM 1206 TAPE 746453 1 RESISTOR SMR RES CERM 6 2K 125W 200PPM 1206 76 1 RESISTOR SMR RES CERM 75 5 125W 200PPM 1206 2 R10 16 RESISTOR SMR RES CERM 10K 195 125W 100PPM 1206 7697 7 R51 54 RESISTOR SMR RES CERM 5 11K 1 125W 100PPM 1206 810663 4 R56 R17 RESISTOR SMR RES CERM 1K 1 125W 100PPM 1206 aan 2 6 69 5790 6 70 R58 59 RESISTOR CERMET 39 2K 1 0 1W 100PPM 0805 TAPE 943092 R60 61 RESISTOR CERMET 1M 1 0 25W 100PPM 1206 TAPE 83687 SWITCH MICRO PUSHBUTTON SPST MOMENTARY 24VDC 30MA SMT TAPE TRANSFORMER SIGNAL 1 1 0 3 150MHZ 1515 TAPE 690669 1 3 14 CONNECTOR TERMINAL TEST POINT SMD 510 PH BRONZE TAPE DEM BPLR TL7705A SUPERVISOR 5V SENSE SOIC 780502 EX NL OUTPUTS SOIC14 TAPE a NNI F INVERTER UNBUFFERED SOIC ll CLR SOIC16 EEE SOICW24 TAPE SOICW24 TAPE IC MICROPROCESSOR MC68HC000 16 BIT 5V 10 866777 MHZ PLCC68 TUBE CMOS 74HC32 SMR IC CMOS CMOS 74HC32 SMR IC CMOS QUAD 2 INPUT OR 2 INPUT OR GATE SOIC 783712 KW ET SE SOICW24 NGC ENDURANCE PLCC32
276. n Multifunction Calibrator Fluke 5700A 50 Type Coaxial Tee Male Male Male Amphenol 4850 or equivalent 50 Female to Double Banana Plug Adapter Pomona Model 1740 or Equivalent Binding Posts to 50 O Type Male Adapter Pomona Model 1796 or Equivalent Low Thermal Test Leads Fluke 5440B 7002 or equivalent two sets The 5700A must be characterized for DC using the procedure in this section 1 Setthe rear panel CALIBRATION MODE switch to PERIODIC You do not need to change the setting of the CALIBRATION STORE switch yet 2 Setup the equipment as shown in Figure 3 5 A shielded twisted pair is recommended for the 5700A SENSE leads Note Thermal emf errors can adversely affect AC DC transfers used in the following procedures To minimize thermal emf errors use low thermal emf cables and connectors and avoid changing the temperature of any connection during a procedure It typically takes five minutes to thermally stabilize a connection after it has been touched 3 Turnon the 5790A and 5725 and allow 30 minutes warmup time 4 Setthe 5700A to EXT SENSE Verify that the shorting strap is connected between GUARD and GROUND Set the 5790A to EXT GUARD 5 Press the UTIL MENUS key followed by Cal softkey The top level calibration menu appears Done Cal Zero See Cal Update With Cal Cal Reports Cal Cal Dates Dates La La La La La 4
277. n DC voltage 1s required to produce the same output in the transfer standard under test AC DC Difference A measurement of an AC DC transfer device s cury The AC DC difference is a transfer device s error when it compares a DC voltage to the same RMS voltage A positive AC DC difference indicates that more alternating than direct voltage 1s required to produce the same reading Base Units Units in the SI system that are dimensionally independent All other units are derived from base units The only base unit in electricity is the ampere Buffer 1 Anarea of digital memory for temporary storage of data 2 An additional amplifier stage to reduce output impedance levels Burden Voltage The maximum sustainable voltage ross the terminals of a load Calibration The comparison of a measurement system or device of unknown cury to a measurement system or device of known and greater cury to detect or correct any variation from required performance of the unverified measurement system or device Also see verification and treability Calibration Constant A coefficient that is applied manually or automatically to adjust the output or reading of an instrument Calibration Curve A smooth curve drawn through a graph of calibration points Calibration Interval The interval after which calibration must occur to maintain the performance of an instrument as stated in its specifications Appendices A Glossary of AC DC Transfer
278. n point that correct gain zero DC turnover and flatness errors 3 12 Update Cal Dates Menu Pressing the Update Cal Dates softkey produces the following menu Prev Update Update Update Cal ALL AC amp DC WBND Menu Dates Date Date a La 4 4 There is only one case in which you would use these functions If you perform a complete main input calibration or wideband calibration process and not a single significant shift was detected you press one of these keys to update the date and temperature of the stored set of calibration constants to the current date The rear panel elu016 eps Calibration and Verification 3 Periodic Calibration CALIBRATION STORE switch must be set to ENABLE to update the cal dates Updating the calibration date in this way does not generate a new set of calibration constants 3 13 Periodic Calibration The following information describes how to calibrate the 5790A to external standards You can substitute either manual or automated equivalent equipment and methods for the following calibration procedures but only if the equipment and standards used have uncertainties equal to or better than specified During 5790 calibration select the fast medium or slow filter 3 14 Calibrating the Main Input Calibrate INPUT1 or INPUT2 by using the following sequence of procedures 1 Characterize the DC source 2 Perform DC calibration 3 Perform AC cal
279. n the filter element a Wash the filter element in soapy water b Rinse the filter element in fresh running water c Shake out the excess water then allow the filter element to dry thoroughly before reinstalling it 3 Reinstall the filter element its retainer and the knurled screw 4 3 General Cleaning To keep the 5790A looking like new clean the case front panel keys and lens using a soft cloth slightly dampened with water or a non abrasive mild cleaning solution that does not harm plastics A Caution Do not use aromatic hydrocarbons or chlorinated solvents for cleaning They can damage the plastic materials used in the 5790A 4 3 5790 Service Manual 4 4 w JOHN FLUKE MFG CO INC MADE IN U S A VARIOUS ASPECTS OF THIS INSTRUMENT ARE PROTECTED BY ONE OR MORE OF THE FOLLOWING PATENTS US 4716398 ADDITIONAL PATENTS PENDING NO INTERNAL USER SERVICEABLE PARTS REFER SERVICE TO QUALIFIED PERSONNEL TO CLEAN FILTER REMOVE FROM INSTRUMENT AND FLUSH WITH WARM SOAPY WATER CAUTION FOR FIRE PROTECTION REPLACE ONLY WITH A 250V FUSE OF INDICATED RATING VOLTAGE FUSE F1 VOLTAGE SELECTION SELECTION FUSE F1 CHASSIS GROUND 52 53 54 52 53 54 10v BOG 200v BOG 120v EB IM RS 232 Figure 4 1 Accessing the Air Filter 4 4 Clean
280. nd gives current drive to the DAC output To change the DAC voltage the average value of the two square waves must be varied To determine the average value multiply the waveforms amplitude by its duty cycle Vary the duty cycle and keep the amplitude fixed to change the DAC voltage For example if the duty cycle of the first channel 15 10 and the second channel 50 95 the overall average voltage would be 0 1x13V 0 5x0 78mV 1 300390 The duty cycle resolution is 0 0024 which gives a first channel resolution of 0 309 mV and second channel resolution of 18 5 nV The duty cycle control circuitry creates the two digital square waves for the first and second channels These two waveforms are first run through the optocouplers for isolation and then into analog switching and level shifting circuits These circuits derive the proper signals to switch the input of the filter at the levels explained above 0 78 mV DC TPS NEGATIVE OFFSET DUTY CYCLE 5 CONTROL CHAN 2 REFERENCE rd Z TP7 OUTPUT CHAN 1 STAGE 18V DC DUTY CYCLE V CONTROL SHUNT SENSE LINEARITY LINEARITY CURRENT CONTROL CONTROL CANCELLATION elu011 eps Figure 2 9 A16 DAC Assembly Block Diagram 2 98 DAC Assembly Reference Circuitry As previously explained the amplitudes of the pulse width modula
281. nd FET 04 15 also turned on This causes U38 to supply the current to the filter through the 15 710 resistor in 4HR9 and Q4 which makes the resistance from TP2 to TP5 look like near 0 ohms The shunt linearity control circuit uses op amp U2B FET 022 two 80 resistors on the 4HR6 assembly and one resistor in the 4HR9 assembly Op amp U2B is configured as an amplifier with an inverting gain of 1 This gain is determined by the two 80 resistors in the 4HR6 assembly When the shunt switch FET Q6 is on connecting the input of the filter to REFCOM the current from the filter flows through the two 40 resistor pin 7 to pin 8 on 4HR6 assembly to the output of U2B This cancels out the current that would flow through Q6 which makes it look like 0 Negative Offset Circuit This circuit creates a constant offset voltage of approximately 127 mV at the filter input Thus for a DAC output voltage of 0 V the first channel count must be approximately 400 to offset this negative voltage This guarantees a minimum duty cycle pulse width of approximately 50 us This minimum duty cycle is necessary to overcome the offset of the output stage and to allow the reference voltage to settle out after being switched into the filter input Op amp U2A and two 20 resistors in 4HR6 form an amplifier with an inverting gain of 1 This amplifier input is the 13 V reference which produces 13 V at its output This 13 V is divided by re
282. nder test The initial calibration at Fluke is done at 23 You can verify the temperature of the last calibration at any time by pressing the SPEC key Use the Relative Uncertainty Specifications if you use a different procedure to calibrate the 5790A than is specified in the 5790A Service Manual To calculate absolute uncertainty specifications under such conditions combine the absolute uncertainty associated with your external equipment and calibration procedures with the Relative Uncertainty Specifications Secondary Performance and Operating Characteristics are provided for special calibration requirements such as stability or operation at temperature extremes 5790 Service Manual Absolute Uncertainty Specifications 5 C of Calibration Temperature Absolute Uncertainty Measurement Mode Voltage Range Frequency Range pod ppm of Reading uV 2 Years 90 Days 1 2 Years 10 Hz 20 Hz 1700 1 3 1700 1 3 1700 1 3 20 Hz 40 Hz 740 1 3 740 1 3 740 1 3 40 Hz 20 kHz 420 1 3 420 1 3 420 1 3 20 kHz 50 kHz 810 2 0 810 2 0 820 2 0 uid 50 kHz 100 kHz 1200 2 5 1200 2 5 1200 2 5 100 kHz 300 2 2300 4 0 2300 4 0 2300 4 0 300 kHz 500 kHz 2400 6 0 2400 8 0 2600 8 0 500 kHz 1 MHz 3200 6 0 3500 8 0 5000 8 0 10 Hz 20 Hz 850 1 3 850 1 3 850 1 3 20 Hz 40 Hz 370 1 3 370 1 3 370 1 3 40 Hz 20 kHz 210 1 3
283. nt Panel Assembly A2 asss Clock Regeneration Circuitry Refresh Failure Deject Circuitry Decoding and Timing Circuitry Control Display sees Measurement Display M Keyboard Scanner Circuitry esee LED Circuitry Keyboard Assembly LAIR Analog Section Detailed Circuit Description Filter Assembly A18 Unregulated CH Supplies sees Unregulated LH Unregulated 17 SR Triac Circuit Supplies Unregulated Supply seen FR2 Supplies Regulator Guard Crossing Assembly 17 Voltage Regulator Circuitry esses Regulated LH Regulated 17 S Regulated 15 CH Supplies sese Supply FR2 Supply Guarded Digital Control Circuitry sss Transfer Assembly A10 sse Input Signal Paths Precision Amplifiers Thermal Sensor Circuit essen Digital Interface and Control A D Amplifier
284. ntinuous overload the protection circuit oscillates between these two states To facilitate rapid auto ranging the output of U4 generates an interrupt signal for the CPU by turning on Q6 This way the CPU can react quickly to an overload at the FTS Digital Interface and Control An 82C55 peripheral interface IC on the Analog Motherboard latches in the digital control signals A pair of UCN5801 power drivers U20 and U21 controls relays Three octal latches U22 through U24 control the solid state switches Components U34 U36 Q5 and Q6 process the overload and the protection interrupts Theory of Operation 2 Analog Section Detailed Circuit Description 2 83 A D Amplifier Assembly A15 2 84 2 85 2 86 The A15 A D Amplifier board contains circuitry for generating the chopped DC reference for the A10 Transfer assembly and circuitry for measuring the output of the Fluke Thermal Sensor circuit also on the Transfer assembly The chopper circuit is described first followed the A D amplifier and then the frequency counter Chopper Circuit Refer to Figure 2 7 for a block diagram of the chopper circuit The chopper circuit contains the following main circuit blocks 2 divider DC reference select e Precision inverter Chopper oscillator Chopper switches Chopper attenuators OUTPUT 2V DIVIDER FROM DC REFERENCE A16 DAC SELECT PRECISION INVERTER io CHOPPER CHOPPER jan
285. oard 8255 chip Note that if all the digital tests fail 8255 and 8254 tests it is more likely that there is a problem with the guard bus interface from the A17 Guard Crossing assembly Test Step DAC8254 DAC 8254 This test checks the DAC 8254 counter Counter 0 1 and 2 registers are checked to see if they equal the appropriate default setting Possible errors include Error Code 3002 A16 DAC 8254 Counter O Test Failed Error Code 3002 A16 DAC 8254 Counter 1 Test Failed Error Code 3002 A16 DAC 8254 Counter 2 Test Failed elu055 eps These errors suggest the A16 DAC 8254 is faulty Note that if all the digital tests fail 8255 and 8254 tests it is more likely that there 15 a problem with the guard bus interface from the A17 Guard Crossing assembly Test Step AD8255 A D 8255 This test the A D 82C55 It sets the CTRL register to default value reads and verifies The process is as follows 1 Set A register to default value read and check 2 Set B register to default value read and check 3 Set C register to default value read and check 4 Execute pattern write read test on port Possible errors include Error Code 3000 A15 A D 8255 Control Word Test Failed Error Code 3000 A15 A D 8255 Port A Test Failed Error Code 3000 A15 A D 8255 Port B Test Failed Error Code 3000 A15 A D 8255 Port C Test Failed elu056 eps Failure of this test suggests a bad A15 A D 8255 chip Note that if all the digit
286. on the 5790 Proceed to each of frequencies listed Table 3 8 Set 5700 frequency and adjust the 5700A to give the same error on the 5790A display as recorded in the table from the previous steps Record the error displayed by the 5700A both magnitude and sign in Table 3 8 in PPM The 5700A 1s now characterized and be used to calibrate the 5790A Calibrating Wideband Input Gain at 1 kHz Proceed as follows to perform gain absolute calibration at 1 kHz for each range You do not need the worksheet for this part of WIDEBAND calibration l Connect the equipment as shown in Figure 3 12 Set the 8506A in the HI ACCUR mode Press the UTIL MENUS and then the CAL softkeys Press the CAL and then the WBND CAL softkeys This produces the following display Prev Full WBND Calibration Cal ENTER the ambient temperature in C Menu Temperature 23 0 15 to 35 4222224 elu038 eps Enter the ambient temperature on the number keys and then press ENTER or press ENTER to accept 23 0 C The 5790A will step to the first calibration point on the 7 V range Apply 3 0 V at 1 kHz and then press DO STEP softkey 3 31 5790 Service Manual 3458A DISCONNECT DMM CABLE 70 RANGE CAL 5790 MEASUREMENT STANDARD 5700A CALIBRATOR WIDEBAND A 5 WIDEBAND ourur N
287. one refresh cycle is insignificant U5 also generates the FPINTR front panel interrupt active low signal sent to the 68HC000 microprocessor telling it there is a keyboard interrupt Keyboard interrupt inputs to U5 KEYBOARDINTR active high is generated by PLD U9 Keyboard Scanner Circuitry The key matrix is scanned by PLD 09 It sequentially drives one of the eight columns for about 2 2 ms then reads all the six rows of the matrix on each column scan When a key is pressed and the column associated with that key is scanned the row associated with that key goes low If key is still pressed after 6 6 ms debounce period U9 generates signal KEYBOARDINTR This signal goes to US where it generates FPINTR which interrupts the 68HC000 microprocessor The microprocessor generates KEYBOARDCS through PLD U3 causing U9 to output encoded row and column data on the data bus for the microprocessor to read This also resets the keyboard interrupt The microprocessor controls the speaker also referred to as the beeper Writing a logic high on the data line D6 to U9 enables the speaker writing a logic low on D6 disables the speaker When enabled 900 Hz square wave signal generated by US is gated out to the speaker through U9 LED Circuitry The LED circuit controls the six keycap light emitting diodes on the Keyboard assembly It includes a 74LS373 8 bit latch U10 and resistors R16 through R19 and R78 through R80 Keycap LEDs l
288. oninverting configuration The DC Amplifier Assembly interfaces with the output buffer U5 to create the output stage The output buffer provides drive for the DAC output It is used in a feedback loop with the DC Amplifier Hybrid so that the DC accuracy 15 dependent upon the DC amplifier and the output drive capability is dependent on the output buffer Sense Current Cancellation Circuit This circuit supplies the sense current of equal but opposite polarity to the current in the feedback resistors This eliminates current in the sense connection DAC SNS HI Components and four resistors the 4HR6 assembly do this task Linearity Control Circuit The linearity control circuitry contains the series linearity control circuit and the shunt linearity control circuit as labeled on the schematic These linearity control circuits eliminate filter current in the series switch Q5 and the shunt switch Q6 This 15 necessary because Q5 and Q6 have finite resistance 3 to 5 and a small mismatch in the resistances can cause a linearity error 2 104 2 105 Theory of Operation 2 Analog Section Detailed Circuit Description The series linearity control circuit uses op amp U38 resistor network Z2 and a single 15 710 resistor on the 4HR9 assembly This circuit eliminates filter current in the series switch Q5 When the series switch FET Q5 is on it connects the 13 V reference to the first channel input of the filter a
289. onvert each count into a stable TTL level square wave with a duty cycle proportional to the numeric value of the count The 82C54 programmable interval timer U6 and 8 MHz clock U7 generate this signal The 82C54 programmable interval timer receives its input counts from the guarded digital bus and creates the second channel signal on OUT2 pin 20 and the first channel signal on OUT 1 pin 16 The second channel signal 15 buffered by U8 D and E and runs through the opto isolator 012 to become CH2 FLOATING This signal alternately turns FETs Q30 and Q32 on and off to turn the 3 V source called 3 V into a floating 3 V pulse width modulated waveform called CH2 FILTER INPUT 2 43 5790 Service Manual 2 44 2 100 2 101 2 102 2 103 3 source 15 created from 13 V reference 13 V reference is buffered amp UIB configured as voltage follower The output from U1B 15 divided down to 3 V by a 100 and 30 resistor in the 4HR9 assembly creating 3 V This 3 V is again buffered by op amp U11 configured as a voltage follower to create the 3 V which is switched by FETs Q30 and Q32 CH2 FILTER INPUT uses three resistors on the 4HR9 assembly to resistively divide its 3 V amplitude by an additional factor of approximately 3800 The first channel signal is buffered by U8 G and H and run through the opto isolator 013 to become FLOATING Since the first channel is much more critic
290. or 5790A Main Input DC Calibration Calibration Steps in Periodic Calibration essen Equipment Required for 5790A Main Input AC Calibration Equipment Required for Wideband Calibration Wideband Calibration Worksheet sss Attenuators Required for Each Calibration Steps in Service Calibration sss Wideband Amplifier Rolloff Adjustment Worksheet Main Input Verification 5 Test Record for Main Input Worksheet for Wideband 22 mV 7 mV and 2 2 mV 1 kHz Gain Wideband Flatness Verification Worksheet Wideband Verification Test 4 Manual Status Information eene ener 1 EE 62 Input Block nnne Al Keyboard PCA Front Panel Analog Motherboard 1 2 012 4 000 0 00 5790 4 Motherboard enne Wideband PCA Option 03 nnne RMS Support
291. otherboard A 75451 driver IC U32 drives the fiber optic transmitter on the digital Motherboard The DUART has 8 output lines that perform various functions INTRCNTL and INTRCNTL2 go to the interrupt controller and are fed back to the DUART inputs These are used by the interrupt controller to enable certain interrupts Line SCLK 15 a test output of the channel A serial clock The DUART monitors the EEPROM ready signal and the FANINT signal It also has spare serial channel that goes to the connector J5 Components U44 and U43 convert the TTL level signals at the DUART to RS 232 C level signals at 15 The DUART generates its own DTACK signal DRTDTK which is used by 05 to generate system DTACK A second DUART 042 with associated RS 232 C drivers and receivers is used only for test purposes It generates its own DTACK wire ORed to DRTDTK Clock Calendar Circuit Time and date information is stored in a battery backed clock calendar circuit consisting of 32 768 kHz crystal Y3 3 V lithium battery 1 clock calendar IC 033 and capacitors C10 and C11 The clock calendar IC has the necessary circuitry internally to switch operation from the power supply to the battery BT1 Pull up resistors in Z5 off U33 are to ensure the low power operation when the 5 V supply is off U33 generates CLKCALINT under software control Clock Filter Circuit The clock filter circuit generates a 3 6864 MHz 200 mV sine wave for the R
292. ous connection from U2 to the amplifier 2 33 5790 H3H1ON ASSV Q V OL LNO ASSY Q V AML AOOL S667 005 S39NVH LZ OL LNO N L AZZ A S35NVH 009 3H 1 NOI LO31Otid L LAdNI elu008 eps Figure 2 6 Divider Network Simplified Schematic 2 34 2 77 2 78 2 79 2 80 Theory of Operation 2 Analog Section Detailed Circuit Description 7 to 220 V Ranges For inputs in the 7 V to 220 V ranges relay K3 or K4 applies the selected input to 200 V 22 V divider Z1 This divider has 2 taps a divide by 100 for the 220 V and 70 V ranges and a divide by 10 for the 22 V and 7 V ranges for the frequencies below 100 kHz The divide by 100 tap is also used for the 7 V and 22 V ranges above 100 kHz Relay routes the output of the divide by 10 tap to the input amplifier U1 This relay prevents excessive voltage from appearing at the input of U1 while in the 220 V range The divide by 100 tap goes directly to U1 In the 7 to 220 V ranges AC chopped DC transfers are done by alternately closing the KV and DC and either 220 V or 22 V channels of U1 In these ranges the U2 CHOP switch is always closed Millivolt Ranges
293. plifier assembly through the instrumentation amplifier input switching then through the instrumentation amplifier to the A D chip U24 inputs Test Step CHOPPER A D Chopper This tests the chopper in 0 dB 20 dB 40 dB and 60 dB ranges Since the A D can only measure DC chopper ranges are tested by stopping the chopper in either the high or low state With the chopper running the A D should measure about 0 0 This tests both the fast and slow frequency chop rates It leaves A D Amplifier assembly in the dormant state on exit The test proceeds as follows l Configure with DAC set to 1 0 driving DIVOUT which drives the chopper Stop chopper with output in high state Chopper set in 0 dB range Route chopper output to SDL Measure chopper output with SDL A D range Stop chopper with output in low state Measure chopper output with SDL A D range Set chopper in 20 dB range Stop chopper with output in high state Measure chopper output with SDL A D range Set chopper in 40 dB range Stop chopper with output in high state Measure chopper output with SDL A D range Set chopper in 60 dB range Stop chopper with output in high state Measure chopper output with SDL A D range Set chopper in 0 dB range Start chopper running at slow rate Measure chopper output with SDL A D range Should be about 0 Use A D to check chopper frequency at slow rate Set chopper to 0 dB range Start chopper running at fast rate Measure chopper o
294. prevent the watchdog timer from going off unless the watchdog is disabled by holding CLRCNTR high Power Up and Reset Circuitry This circuit consists of U60 SW51 C55 C56 R52 and 751 The line monitor chip U60 detects three events the power supply falling below 4 5 V reset being initiated by closure of momentary contact switch SW51 or BREAK being asserted from the break detection circuitry If any of these conditions occurs U60 resets the board for 130 spin 5 and 6 of U60 are open collector outputs pulled high by Z51 and low by Z55 Break Detection The break detect circuit acts as a serial communications break detector enabling the CPU Assembly A20 to reset the microcontroller U56 via the power up and reset circuitry This break detect circuit uses a 74 4020 counter 063 and an inverter 051 The microcontroller U56 outputs a 19 2 kHz square wave SCLK on pin 11 This signal clocks U63 which in turn divides the signal by 4096 to produce successive logic low and high intervals each of 106 ms at the BREAK output U63 pin 1 Under normal conditions the RCV receive line is high to hold U63 clear The main 68HC000 CPU can force a reset of the Guard Crossing over the fiber optic link by holding RCV low for more than 106 ms which causes BREAK to go high BREAK inverted by U51C is used by the reset circuitry to force a Guard Crossing reset via RESET Fiber Optic Link to CPU Guarded digital and analog circuits are isol
295. put ratio OF 2 2MV foo Full scale calibrated DC offset Table C 8 Group ZC_2_2MV More DC Constants 2 2 mV Range Z 2_2MV 00 Zero calibrated DC offset SHO_2_2MV 00 4 Shunt input DC offset IA 2 2MV 0 001 Rough gain input to A D ratio Appendices Calibration Constant Information Table C 9 Group AC 2 2MV Flatness Constants 2 2 mV Range TEY TIT F2 2 TT 2 PMV TT Table C 10 Group DC 7MV DC Constants 7 mV Range DI 7MV 1000 0 Basic gain Ref DAC to input ratio OF 7MV foo Full scale calibrated offset Table C 11 Group ZC_7MV More DC Constants 7 mV Range 2 7 foo Zero calibrated DC offset SHO_7MV o Shunt input DC offset IA 7 0 00316228 Rough input to A D ratio Table C 12 Group AC 7MV Flatness Constants 7 mV Range Table C 13 Group DC 22MV DC Constants 22 mV Range DI 22MV 500 0 Basic gain Ref DAC to input ratio OF 22MV foo Full scale calibrated DC offset 5790 Table 14 Group ZC 22MV More DC Constants 22 mV Range Z 22MV 00 Zero calibrated DC offset SHO 22MV 00 Shunt input DC offset _22 0 001 Rough to A D ratio Table 15 Group 22 Flatness Constants 22 mV Range Table C 16 Group 70MV DC Constants 70 mV Range DI 70MV 100 0 Basic gain Ref DAC to input ratio OF 70MV foo Full scale calibrated DC offset Tabl
296. qapanaasyasqaqasapasqasssacasqaqaaqsscaysastassqsa 5 6 Test Step 8255 Motherboard 8255 5 7 Test Step DAC8254 DAC 8254 5 8 Test Step AD8255 A D 8255 5 9 Test Step ADSELFTEST A D Internal Selftest 5 10 Test Step ADZEROS A D Zeros 5 11 Test ADNULLDAC A D Null DAC 5 12 Test Step ADDAC A D DAC Output 5 13 Test Step CHOPPER A D Chopper 5 14 Test Step PROT 5 15 Test Step OVLD Overload 5 16 Test Step ZEROS ws 5 17 Test Step DIVIDERS Input Dividers 5 18 Test Steps X2 2V through X2 2MV 5 19 Test Step MATCH Sensor Match 5 20 Test Step XFREQ Frequency Measuring 5 21 Test Step LOOPFILT Sensor Filter 5 22 Test Step WOVLD Wideband Overload 5 23 Test Steps W7V through W2 2MV Wideband 2 2 mV Range 5 24 Test Step WFREQ Wideband Frequency Measuring
297. quantification of incury Units Symbols or names that define the measured quantities Examples of units are V mV A kW and dBm See also 51 System of Units UUT Unit Under Test An abbreviated name for an instrument that is being tested or calibrated 5790 Volt The unit of emf electromotive force or electrical potential in the SI system of units One volt is the difference of electrical potential between two points on a conductor carrying one ampere of current when the power being dissipated between these two points 15 equal to one watt The unit of power in the SI system of units One watt is the power required to do work at the rate of one joule second In terms of volts and ohms one watt is the power dissipated by one ampere flowing through a one ohm load In instrumentation wideband refers to the ability to measure or generate signals in the radio frequency spectrum Verification The comparison of a measurement or source device UUT with a measurement or source device of known and lesser uncertainty to report variation from required performance Verification does not include adjustment or reassignment of values to UUT and is often done to determine whether the adjustment is necessary Also see calibration Working Standard A standard that is used in routine calibration and comparison procedures in the laboratory and is maintained by comparison to reference standards Zero E
298. quantity special notes 1 factory selected part ACaution A 4symbol indicates a device that may be damaged by static discharge How to Obtain Parts Electrical components may be ordered from the Fluke Corporation and its authorized representatives by using part number under the heading Fluke Stock No In the U S order directly from the Fluke Parts Dept by calling 1 800 526 4731 Parts price information is available in a Fluke Replacement Parts Catalog which is available on request In the event that the part ordered has been replaced by a new or improved part the replacement will be accompanied by an explanatory note and installation instructions if necessary To ensure prompt delivery of the correct part include the following information when you place an order Instrument model and serial number Part number and revision level of the containing the part e Reference designator Fluke stock number e Description as given under the Description heading Quantity Manual Status Information The Manual Status Information table that precedes the parts list defines the assembly revision levels that are documented in the manual Revision levels are printed on the component side of each Newer Instruments Changes and improvements made to the instrument are identified by incrementing the revision letter marked on the effected pca These changes are documented on a supplement manual
299. r Same as zero error The reading shown on a meter when input value of zero 15 applied Is 1ts offset or zero error Parameters Independent variables in a measurement process such as temperature humidity test lead resistance etc Precision The degree of agreement among independent measurements of a quantity under specified conditions The precision of a measurement process 15 its coherence or repeatability Note that while precision 15 necessary for cury it does not imply it Predictability measure of what 15 known of the time behavior of a device A documented drift rate with understood charteristics e g linear exponential can be highly predictable Primary Standard A standard defined and maintained by some authority and used to calibrate all other secondary standards Process Metrology Trking the cury drift of calibration and other equipment by applying statistical analysis to correction ftors obtained during calibration Random Error Any error which varies in an unpredictable manner in absolute value and in sign when measurements of the same value of a quantity are made under effectively identical conditions Range Stated upper limits of measurement or source values for which given uncertainty specifications apply Also see and scale Reference Standard The highest echelon standard in a laboratory the standard that is used to maintain working standards that are use
300. r 90 90 Days Absolute Error Spec Measured Absolute Error 96 22 10 mV 700 kHz No Spec 1 2 MHz No Spec 10 MHz Spec 12 MHz Spec 15 MHz Spec 17 2 3 Spec 20 MHZ Spec 23 MHZ No Spec 26 MHz Spec 28 MHZ No Spec 30 MHz Y No Spec 20 kriz x 3 2 mv 50 KHZ 32nv 3 2 mv 20 kriz 3 2 mV 50 kHz 3 2 mV 100 kHz 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 mV 10 mV 22 10 mV 22 mV 10 mV 22 mV 10 mV 7 mV 3 2 7 mV 7 mV 7 mV 7 mV 3 2 7 mV 3 2 7 3 2 7 3 2 7 7 167 168 170 171 173 174 175 177 178 180 181 183 184 185 187 188 190 191 193 194 195 197 7 BI Eee SEITE 3 62 Calibration and Verification 3 Verification Table 3 16 Wideband Verification Test Record cont 5790A Range Test Voltage Frequency If Using Methods Other Than Specified Max Uncert 1 Yr Flatness Specification Measured Flatness Error 90 90 Days Absolute Error Spec 76 Measured Absolute Error 96 m sone one s 9 1 sem sowe ow om oss rw om Fm oam ons
301. r Arn SWITCHES gt ATTENUATORS gt TRANSFER CHOPPER ASSEMBLY OSCILLATOR Figure 2 7 Chopper Circuit Block Diagram 2 V Divider DC Reference Select Line S COM is supplied through resistor R4 when the chopper is not in use DAC SNS HI is supplied 2 2 to 7 V on the 7x10 n ranges available at TP8 A 5 1 divider Z6 pins 8 10 is switched in to supply 0 7 to 2 2 V on the 2 2x10 n ranges available at TP7 16 is at RCOM Precision Inverter This block provides 0 7 to 7 V from a 0 7 to 7 V input using an LTC1043 U9 as a switched capacitor inverter Capacitor C9 sets the frequency of an internal oscillator which continuously alternates the switches at about 400 Hz Capacitor C5 is charged through R7 with a positive voltage inverted then discharged into C6 This provides a negative reference voltage without introducing the offset voltage of an op amp or the temperature coefficient of a resistor network The output of this circuit is available at TP3 2 37 5790 Service Manual 2 38 2 87 2 88 2 89 Chopper Oscillator This block provides a pair of square waves 50 duty cycle 180 degrees out of phase that clock the chopper switches 4047 U8 is configured as an astable multivibrator Resistor R2 and C4 control the 31 5 Hz rate except when wideband operation 15 selected where U13 switches R15 in parallel with R2 to change the frequency to 80 Hz Lines OSC SET and OSC RESET
302. r PCA 7 31 5790 m HIE y OB E L 3 k ME NN P F gt mE 5790A 1615 Figure 7 12 A10 A D Amplifier PCA 7 32 Schematic Diagrams 7 2V DIVIDER DC REFERENCE SELECT 17 5 cre UNLESS OTHERWISE SPECIFIED 1N4448 ALL RESISTORS ARE IN OHMS us ALL CAPACITOR VALUES ARE IN MICROFARADS DAC SNS HI TTE 06444 FOR ASSEMBLY DRAWING 5790 7615 U14 7 SHT DAC DUT gt DAC SNS 15790 4805 DIV OUT TESTPOINTS RCOM INV 2008 ong CHOP HI 2v DIV DAC SNS HI AD ADT RCL NUL 50 01 4010 RCOM DAC OUT LO Q N D D m m fo esr OSCILLATOR WB SELX U26 4B SHT 3 CHOPPER CH DIAG SEL 9 U26 25 SHT 3 SDL TPG P445 14A 110 SHT 2 OSC SET T 15 26 19 SHT 3 05 RESET R10 40SEL 4 U26 20 SHT CH 1 026 24 SHT 3 pale 15 T B 2 4 CHOP ON 86271 3 26 UeG 21 SHT 3 7 7 15790A 4R06 VS ask 05 14 SHT 1 v U15 2 SHT 2 025 MAX430 MA WB CHOP HI XF CHOP HI i l el WB CHOP LO XF CHOP LO 026 23 SHT 3 S 0 20 40 600 ATTENUATOR 2N3906 MAX430 AA 5790A 1015 1 of 3 Figure 7 12 A10 A
303. r assembly also supplies AC voltages to the Digital Power Supply assembly which generates five regulated DC voltages for use by the CPU Front Panel assembly Rear Panel I O assembly and the cooling fans Analog Motherboard Assembly A3 The Analog Motherboard contains the connectors for all assemblies in the guarded section of the 5790A The Analog Motherboard also contains five relays a fiber optic transmitter a fiber optic receiver and a cable for binding post connections Table 2 1 lists Analog Motherboard connectors The fiber optic transmitter J72 and the fiber optic receiver J71 provide the serial communication link between the Regulator Guard Crossing assembly and the CPU assembly on the unguarded Digital Motherboard 2 9 5790 Service Manual The cable from the motherboard to the binding posts consists of three insulated wires and four shields Table 2 1 Analog Motherboard Connectors Motherboard Connector Connected to Assembly J106 and J206 Wideband A6 Option 03 J110 and J210 Transfer A10 2 10 Rear Panel Assembly A21 The Rear Panel I O assembly provides the RS 232 C and IEEE 488 interface connections 2 11 Hear Panel Power Supplies Supplies 5 V LOGIC 12 V and 12 V are referenced to 5 V LOGIC COMMON and are generated on the Digital Power Supply assembly A19 Some ICs on the A21 assembly do not have power and ground pins shown on the schematic This information 1s included in the tab
304. r to Figures 3 5 and 3 8 for test setups Table 3 12 Main Input Verification Regions AC DC Difference Error Absolute AC Error 70 mV through 700 mV Region III Region IV To do the procedure manually make copies of the rest of the worksheets in this section before you proceed Table 3 13 is the overall test record for main input verification 3 43 5790 Table 3 13 Record for Input Verification Voltage V Frequency AC Source Max Uncertainty 90 Day Absolute AC Error Spec ppm Absolute AC Error Measured Absolute AC Error PPM 2 Yr AC DC Error Spec ppm Measured AC DC Error PPM m ETE FS ss amel 0002 mw we END soe we or mr we 0 0022 0 002 10 kHz o 1070 1070 spec 0 0022 002 Es kHz o o rca No SEM 11 0 002 002 5 gt kHz 1800 1810 No spec spec mae hee Eoo d cu Ue 00022 oone zo m 0002 mo em r0 De oom oe woe foer rom pun em eer zone o ser ser 58 DW eer m e wer 58 Ds eer coos ree mo e r De eer oo wee m em 58 17 ooo mee m e 58 ome wes n eer wow e00 wm aae mE D 0 007 0 006 1 MH
305. rcuit During an over current condition the voltage drop across R5 turns Q6 on thus drawing the current away from the base of Q5 and limiting the current flow to the output Diode CR16 protects this circuit from reverse voltage 75 V Power Supply The 75 V power supply powers the grid drivers and anode drivers on the front panel control display circuitry The 75 V supply is full wave rectified then regulated by 36 V zener diode VR6 39 V zener diode VR7 and transistors Q1 and Q3 Zener diodes VR6 and VR7 set the output voltage Transistors Q1 and in a Darlington configuration for current gain are used as an emitter follower Transistor Q4 zener diode VR5 and resistors R2 and R3 make up the constant current source supplying current to the zener diodes and the base of Q3 Current limiting is performed by R1 and Q2 in the same manner as in the 35 V supply Diode CRS protects the circuit from reverse voltage 35 V and 75 V Shut Down Circuit The 435 V and 75 V high voltage supplies are shut down when a fault occurs in the control display refresh circuitry This shut down circuit prevents the Control Display and Measurement Display from burning out and also verifies that the master clock is generating control signals for both displays During normal operation 75 VSD is low turning 010 off Line RESETL pulls the base of Q9 high through R9 turning Q9 on This action in turn pulls the junctions of CR31 CR32 and CR33 CR34 low turnin
306. reater than 1 99999 MHz the output from the circuit is taken from the divider U2 when quad switch U3 closes the switch from pins 3 to 2 and connects the signal to output resistor R11 When quad switch U3 closes the switch from pins 14 to 15 the output is sent on the COUNTER line across the Motherboard to the frequency counter circuit of 15 A D Amplifier assembly where the frequency is measured for display the Measurement Display For frequencies below 2 MHz the output from the circuit is taken from comparator U1 when quad switch U3 closes the switch from pins 10 to 11 and passes the signal to R11 and out the COUNTER line as before Resistors R6 R10 and resistor networks Z2 and Z3 set the bias and signal levels needed on the COUNTER output line The signal level on the COUNTER output line is 400 mV Below 2 MHz additional filtering of the input signal is provided by capacitor C14 which is switched into the circuit by PIN diode is turned on by Q2 when 1 is turned off by the digital control signal FILT The 2 49 5790 Service Manual 2 50 2 114 2 115 frequency on the COUNTER line is equal to the input frequency between 10 Hz and 1 99999 MHz and divided by 16 from 2 MHz to 30 MHz resulting in 125 kHz to 1 875 MHz Digital Control Digital control of the Wideband assembly comes from the instrument digital bus and is stored in latches on the Wideband assembly Relays K2 7 K3 and K8 are controlled b
307. rement Motherboard DV Divider s A10 Transfer Sensor loop settling A6 Wideband Sensor loop settling A16 DAC DAC settling Wideband Dormant protection check A15 A D s linearity Bad Delta Unit 4 13 5790 501 503 504 505 506 507 508 509 700 701 702 703 704 705 706 707 708 709 710 711 712 900 901 902 1000 1001 1002 1003 1004 1100 1101 1102 1103 1104 1300 1301 5 5 5 5 5 5 STA STA Invalid range Can t get Ref Can t set average Ref Can t decode learned string Learned sting checksum bad Recalling unsaved instrument state Already printing a report Eternal guard not available ACK queue full Both sides of GX want to be master Both sides of GX want to be slave Couldn t ACK packet from inguard Bad packet number from inguard Multiple timeouts sending to inguard Inguard indefinite ACKWAIT holdoff Packet too large for inguard Bad ACK packet number from inguard Received invalid control byte Received invalid acknowledgement Link quality indicator below limit Inguard CPU Reset A D measurement failed Protection activated Over voltage for input write failed EEPROM read checksum error Vos Block 96s would not format Bad NV selector d Blocks failed post format check Guard crossing protocol failed to start Analog hardware initialization failed Giving up on initializing hardware NV Memory check
308. rement Assurance Program A program for a measurement process A MAP provides information to demonstrate that the total uncertainty of the measurements data including both random error and systematic components of error relative to national or other designated standards is quantified and sufficiently small to meet requirements Maximum Transfer Time Maximum time that an AC DC transfer can be made to stay within the stated AC DC absolute uncertainty Metrology The science of and the field of knowledge concerned with measurement Minimum V Sub in For eh range of an transfer standard the minimum input RMS voltage for which uncertainty specifications apply Also see RMS Minimum Use Specifications Specifications computed to satisfy the calibration requirements of measurement or source device UUT Usually determined by a specified test uncertainty ratio between the absolute uncertainties of the UUT and its required calibration equipment Also see Test Uncertainty Ratio Noise An undesirable signal that is superimposed a desired or expected signal See normal mode noise and common mode noise Noise Floor For an AC DC transfer standard the transfer uncertainty due to noise ftors Nonvolatile Memory An electronic memory that retains its contents when the power is turned off Normal Mode Noise An undesired signal that appears between the terminals of a device 5790 Offset Erro
309. rews e Top Edge four screws e Bottom Edge three screws 6 Remove the Power Transformer assembly To install the Power Transformer assembly reverse the preceding six steps 4 17 Hybrid Cover Removal When removing the plastic covers from the hybrid assemblies push the ends of the cover retainer pins through from the back of the circuit board The retainer pins can be damaged by attempting to pull the covers off 4 18 Installing a Wideband AC Module Option 03 A Caution The wideband option circuit board assembly contains static sensitive components Use caution to avoid static discharge when handling the board The procedure that follows can be used to install a 5790A 03 Wideband AC Voltage module in a 5790A The option consists of one circuit board This procedure is to be done only at Service Centers 1 Remove the top and bottom covers and analog section cover as described in paragraphs 4 5 and 4 7 2 Referring to Figure 4 5 locate the slot for the A6 Wideband Module 3 Seat the Wideband assembly in the slot 4 Connect the input cable supplied with the option from J1 on Wideband assembly to the front panel WIDEBAND 50 connector 4 9 5790 Service Manual VOLTAGE SELECT SWITCHES RS232 1 21 REAR PANEL LAES 000000 A18 FILTER PCA A17 REGULATOR GUARD CR
310. rror Same as offset error The reading shown on a meter when an input value of zero is applied is its zero or offset error A 10 Appendix ASCII and IEEE 488 Bus Codes 7654 3210 0000 0000 0000 0001 0000 0010 0000 0011 0000 0100 0000 0101 0000 0110 0000 0111 0000 1000 0000 1001 0000 1010 0000 1011 0000 1100 0000 1101 0000 1110 0000 1111 Message ATN True 2 lt gt gt a a lt 1 5790 7654 3210 16 E 0001 0000 DLE DC1 17 0001 0001 DC2 DC3 DC4 NAK SYN ETB CAN EM SUB ESC FS GS RS US 5 amp 18 0001 0010 0001 0011 0001 0100 0001 0101 0001 0110 0001 0111 0001 1000 0001 1001 UNIVARSAL COMMANDS 0001 1010 0001 1011 0001 1100 0001 1101 0001 1110 0001 1111 0010 0100 0010 0101 0010 0110 0010 0111 0010 1000 0010 1001 LISTEN ADDRESSES 0010 1010 0010 1011 0010 1100 0010 1101 0010 1110 19 20 21 22 23 24 25 26 27 28 29 30 31 32 0010 0000 33 0010 0001 34 0010 0010 35 0010 0011 36 37 38 39 40 41 42 43 44 45 46 47 00101111 0011 0000 0011 0001 0011 0010 0011 0011 0011 0100 0011 0101 0011 0110 0011 0111 0011 1000 0011 1001 0011 1010 0011 1011 0011 1100 0011 1101 0011 1110 0011 1111 0100 0000 0100 0001 0100 0010 0100 0011 0100 0100 0100 0101 0100 0110 0100 0111 01
311. s and separate the front panel plastic from the sheet metal 4 7 5790 Service Manual 4 8 4 14 4 15 4 16 4 Remove the nine self tapping screws connecting the Keyboard assembly to the front panel plastic 5 Remove the Keyboard assembly by gently releasing the seven plastic hook catches Work from one side of the board to the other Start at either side by simultaneously releasing a catch and lifting on the board Reverse this procedure to install the Keyboard assembly When reconnecting the wires to the binding posts be sure to include a washer on each side of the ring terminals Refer to the nearby decal or see sheet 4 of the Analog Motherboard schematic in chapter 8 of this manual for proper connection of the output cable to the front binding posts Caution Do not tighten the nuts that hold the wires to the binding posts more than 7 in Ib Force exceeding 7 in Ib can destroy the binding posts Analog Assembly Removal and Installation The analog assemblies are installed in the sequence shown in Figure 4 5 Note that each module cannot be positioned in any other slot and that identifying information on the tab for each module faces forward In all cases the component side of each module also faces toward the front panel Caution Do not touch any circuit area on an analog assembly Contamination from skin oil can produce high resistance paths with resulting leakage currents and possible erroneous rea
312. s the capability of interrupting the CPU The CPU can then handle the interrupt through its own handler routine The data lines between U2 and J1 are buffered by a 75160A U3 data buffer and the command lines Theory of Operation 2 System Interconnect Detailed Circuit Description are buffered by a 75162 U4 command buffer is a standard IEEE 488 connector The shell of this connector is tied to chassis ground for EMI RFI shielding RS 232 C Interface The RS 232 C interface circuit uses a 68C681 DUART 05 1488 line driver U6 and a 1489 line receiver U7 Figure 2 3 shows the RS 232 connector pinout rear panel view The DUART does the parallel serial data conversion and provides two channels of serial RS 232 C communication of which one channel is not used The other channel 15 available to RS 232 C connector 12 to meet serial interface needs between the 5790A and the external world The transmit line TXDA is driven by U6D to TX of J2 pin 2 The receive line RX goes from J2 pin 3 through receiver U7C to the receive line RXDA of the DUART The DUART 05 also has six input lines three of which monitor signals CTSA CAL SWA and CAL SWB The CTS clear to send line from J2 pin 5 goes through receiver U7A becoming Line CAL connects to the rear panel CALIBRATION STORE switch Line CAL SWB connects to the rear panel CALIBRATION MODE switch Output lines transmitted data RTS DTR are as
313. sensor U15 AC input pin 10 The A6A1 module forces a DC voltage into the DC input of RMS sensor U15 pin 6 to balance the heating effect of the AC input As in the A10 Transfer assembly with the RMS sensor balanced the DC input to the sensor is equal to the RMS of the AC input 2 110 Transfer Methodology The DC output from RMS sensor is connected to the RCL line at P106 pins 12A and 12C by FET switch U16 pins 3 to 2 and measured by the 15 A D Amplifier assembly System software takes the A D measurement and programs the 80 Hz square wave signal WB from the A D amplifier whose RMS value is approximately equal to the signal input at the RMS sensor amplifier input Q6 System software switches the WB CHOP signal into either the upper four range or the lower four range signal path as previously described The WB CHOP signal is then adjusted if necessary to give the same DC output of the RMS sensor 1715 as the input 15 alternated between the input signal and the WB CHOP signal at a 1 Hz rate After applying appropriate constants determined when the 5790A was calibrated the RMS value of the input is displayed on the front panel 2 111 DC Offset Feedback for the RMS Sensor Amplifier Amplifier U12 and associated parts provide a DC feedback loop to keep the DC voltage on RMS sensor U15 AC input pin 10 near zero The DC is sensed by resistor R86 amplified by U12 and fed back to input FET pair Q6 at pin 6 The loop adjusts the
314. shown in the connector pinout view NAME FUNCTION GND CHASSIS GROUND TRANSMITTED DATA RECEIVED DATA REQUEST TO SEND CLEAR TO SEND SIGNAL LOGIC GROUND 1 13 14 d pi PANEL VIEW OOOOOOQOOOOO 20 DTR DATA TERMINAL READY elu004 eps Figure 2 3 RS 232 Connector Pinout 5790 Service Manual 2 16 Rear Panel CPU Interface The rear panel is interfaced to the CPU assembly A20 via connector J121 on the rear panel The CPU has e Five address lines RPA1 RPA5 which comprise the ADDRESS BUS Seven control lines which comprise the CONTROL BUS A low level 3 6864 MHz clock CLOCK CLOCK Eight data lines RPDO RPD7 Interfacing between the Rear Panel data bus D100 D107 and the CPU data bus 0 RPD7 is done with a bus transceiver U1 2 17 Digital Section Detailed Circuit Description 2 18 Detailed descriptions of each assembly in the digital section are provided next Digital Power Supply Assembly A19 The Digital Power Supply assembly receives AC voltages from the transformer and provides five regulated DC voltages for use by the CPU the Front Panel assembly Rear Panel I O assembly and the cooling fans All power supply voltages are referenced to COMMON which is the transformer center tap for the 12 V supplies The test points at the top of the assembly can be used to check unregulated input voltages and regulated DC output voltages Table 2 2 lists th
315. sistors in the 4HR9 assembly to create the 127 mV on the filter input Wideband Module A6 Option 03 The 5790A Wideband option extends the 5790A operating range to accept signals from 600 to 7 V over a frequency range of 10 Hz to 30 MHz The input impedance at the front panel WIDEBAND Type N connector is 50 on all ranges Essentially the Wideband Assembly takes over the function of the A10 Transfer Assembly when the 5790 is in Wideband mode Refer to Figure 2 10 and Wideband Assembly schematic diagram for the remaining theory discussion Wideband inputs are made to the WIDEBAND 50 N connector on the front panel and the option is activated by pressing the WBND key In Wideband mode eight input ranges are available 2 2 mV 7 mV 22 mV 70 mV 220 mV 700 mV 2 2 V and 7 V The operator selects the ranges the same way as in standard operation Once the system has settled in the proper range the displays show the amplitude and the frequency of the input The front panel WIDEBAND connector is connected by a cable to the Wideband A6 assembly through board input connector J1 If the input exceeds approximately 14 V pk the A6A2 Input Protection module clears relay driver U26 thereby dropping out all four input relays protecting the circuit from damage If the input is greater than full scale on the highest range 7 V but less than the 14 V trip point of the Input Protection module the Range Compara
316. ssembly to U24 5 25 Test Step WLOOPFILT Wideband Sensor Filter Tests slow mode sensor loop filter settling time Fault 3020 A10 Wideband Sensor Loop Settling Transfer board configured in 7 V wideband range no inputs Special chopper setup 0 dB attenuation Connect sensor output to RCL Positive instrumentation amplifier input to RCL negative to RCOM Sensor loop filter in slow mode Set DAC to 70 mV Let the sensor output settle Measure sensor output with x1 A D range Switch in 40 dB attenuation in chopper Let it settle Again switch out the 40 dB attenuation and then immediately take 8 sample A D readings Compare this reading with first settled reading 5790 Introduction How to Obtain Parts Manual Status Information Newer Instruments Service Centers Parts Lists Chapter 6 List of Replacable Parts Title Page 6 1 5790 6 2 6 1 6 2 6 3 List of Replacable Parts 6 Introduction Introduction This chapter contains an illustrated list of replacement parts for the 5790 Parts are list by assembly alphabetized by reference designator Each assembly 1s accompanied by an illustration showing the location of each part and its reference designator The parts lists give the following information Reference designator An indication if the part is subject to damage by static discharge Description Fluke part number Total
317. stored set At each power up the contents of this nonvolatile memory is copied into the active set memory Therefore the stored set is identical to active set until you perform a new calibration 3 The old set Although it is no longer in use the previous set of calibration constants is saved in nonvolatile memory This set is kept in order to make comparisons in Cal Shift reports AFTER CALIBRATION BUT BEFORE STORING ACTIVE STORED OLD SET SET SET VOLATILE NONVOLATILE NONVOLATILE STORE OPERATION ACTIVE STORED OLD DISCARD SET m SET SET Irc VOLATILE NONVOLATILE NONVOLATILE AT EACH POWER UP ACTIVE COPY STORED OLD SET SET SET VOLATILE NONVOLATILE NONVOLATILE elu013 eps Figure 3 1 5790A Calibration Memory Organization Note For a theoretical discussion of calibration constants refer to Chapter 2 Introduction Calibration and Verification 3 3 7 How to Use Calibration Menus When you press the UTIL MENUS key followed by Cal softkey The top level calibration menu appears as shown below Done Cal Zero See Cal Update With Cal Cal Reports Cal Cal Dates Dates a elu014 eps The functions of the softkeys and the location of related instructions are described next 3 8 The Cal
318. t softkeys The Control Display changes to Done Adjust R21 on Transfer assembly With to center the arrow Adjust LLL GOOD a La La La La 3 24 elu041 eps Adjust R27 if necessary to center the pointer Note the reading on the Measurement Display It shows the offset in mV Try to obtain as close to a zero reading Press Done With Adjust and replace the top cover Wideband Amplifier Rolloff Adjustment If you repaired or replaced the A6 Wideband assembly adjust the amplifier rolloff as follows 1 2 3 4 e 10 11 12 Turn off power and unplug the 5790 Remove the top cover Remove the guard cover Referring to Figure 3 14 locate trimmer caps C24 and C20 C20 is accessed through a hole in the top of the small shield cover Replace the guard cover but do not reinstall the screws Turn on the 5790A and allow 30 minutes for warmup Set up the equipment as shown in Figure 3 10 including the RS 232 video display terminal Set up the terminal and the 57904 serial interface parameters Use the TERMINAL mode rather than COMPUTER Chapter 7 of the 5790A Operator Manual describes how to do this Type the following commands on the terminal followed by the Return key CAL CONST F16 220MV WB CAL CONST F16 70MV WB Enter the results in Table 3 11 Use only the first 6 digits to the right of the decimal point Make the calculations shown
319. t the 1000 V and 220 V input dividers are accessible in the circuit The test proceeds as follows 1 Configure instrument in 1000 V range with no input Inject the chopper Measure the input of the sensor Close the switch that hooks up KV DIV input on the transfer board note that a relay still keeps the input terminals open Again measure the output of the sensor The divider affect of the 500 of the input divider and the switch impedance will shift the reading 2 Configure instrument in 220 V range with no input Inject the chopper Measure input of sensor Close the switch that hooks up the 220 V tap on the input divider note that a relay still keeps the input terminals open Again measure the output of the sensor The divider affect of the 5000 of the input divider and the switch impedance will shift the reading 3 Configure instrument in 22 V range with no input Inject the chopper Measure input of sensor Close the switch that hooks up the 22 V tap on the input divider note that a relay still keeps the input terminals open Again measure the output of the sensor The divider effect of the 500 input divider and the switch impedance will shift the reading 5790 Service Manual Possible errors include Error Code 3013 A10 Transfer 22 V Divider Test Failed Error Code 3013 A10 Transfer 220 V Divider Test Failed Error Code 3013 A3 Motherboard 1000 V Divider Test Failed elu065 eps For the A3 Motherboard 1000 V
320. ted signals for the first and second channels are assumed to be fixed Any change in amplitude shows up as an error on the output of the DAC The DC reference circuitry is very stable and generate little noise 2 99 Theory of Operation 2 Analog Section Detailed Circuit Description The DC reference circuitry 15 on the reference hybrid located on the 4HR9 assembly The 4HR9 assembly contains a ceramic substrate reference hybrid bonded to a resistor network All components on this assembly are surface mount devices except U6 and U7 resistors are screened with a thick film paste Associated resistors capacitors and zener diodes are mounted on the main board to supply this hybrid with operating power and ground returns The 13 V reference contains two cascaded 6 5 V temperature compensated transistor zener diode pairs called ref amps U6 and U7 The excellent temperature characteristics of the ref amps are obtained by biasing the collector current of their transistors with a value such that the TC temperature coefficient of its base emitter junction cancels the TC of the zener diode Since the base emitter junction and the zener diode are in series the result is a near zero TC Correct bias currents are achieved with a thin film resistor network in a surface mount package mounted on the hybrid The reference circuit is designed such that the effects of the thin film resistors and op amp errors are second order Thus accuracy 15 d
321. tes a display with a pointer that helps you make an internal adjustment on the Transfer assembly The adjustment removes the offset in the millivolt input amplifier stage and is required only following repair or replacement of that assembly Instructions for this adjustment are described under Service Calibration 3 9 Zero Cal Softkey Starts the Zero Calibration procedure described in Chapter 4 of the Operator Manual It is recommended that you perform this brief automatic procedure at least every 30 days The setting of the CALIBRATION STORE or MODE switches does not matter for Zero Calibration 3 10 See Cal Dates Softkey This softkey displays the dates of the last zero calibration main calibration service calibration normally when the 5790A was built and Wideband option calibration if installed 3 11 Cal Reports Softkey This softkey produces a menu that lets you print one of the following types of calibration reports through the serial interface MEASUREMENT SHIFTS STORED VS OLD Use this report at any time to see the shifts that occurred at the last stored calibration Note A report of ACTIVE VS STORED measurement shifts is offered only after you have completed a calibration process and not yet stored the updated constants CALIBRATION CONSTANTS Print this report to list the active stored and old set of calibration constant names and values There are many different types of constants for each calibratio
322. the bottom of Table 3 11 27 Raise the front of the guard cover and adjust C20 for 3500 PPM 1000 PPM 28 Set the 5700 to standby and remove the A55 and attenuators 29 Replace the covers and screws 3 42 Calibration and Verification 3 Verification 3 25 Verification Main input verification is presented first followed by WIDEBAND input verification Note All performance limits specified in the test records apply to 90 day specifications for the 57904 For Wideband verification the 2 year or 1 year specifications are used where there are no 90 day specifications If limits to other specifications are desired the test records must be modified Note Equivalent equipment and methods either manual or automated may be substituted for the following verification tests as long as the same points are tested and equipment and standards used are at least as accurate as those specified If standards are less accurate than specified appropriate tolerance limit and or accuracy reductions must be made to achieve equivalent results 3 26 Verifying the Main Input INPUT 1 or 2 Verifying the Main Input requires measurements and calculations that result in over 400 entries in a test record At Fluke an automated procedure is used as described in the introduction to this section Test voltages and frequencies are divided into five regions as defined in Table 3 12 The procedures you use for each region are described next Note Refe
323. the dummy load R14 The remaining current returns to CH COM through the mecca point at TP1 IC U13 pins 1 3 or pins 14 16 select the 0 or 40 dB output from Z2 pin 1 or 3 Capacitors C10 and C11 form a 40 dB capacitive divider to reduce the output impedance at high frequencies Relay K2 routes the output to the A6 Wideband assembly for wideband operation or to the A10 Transfer assembly for all other modes The following chart shows division ratio and attenuation for the various ranges e Input range 2 2 mV divide by 5 20 40 dB attenuators e Input range 7 mV no division by by 5 20 40 dB attenuators e Input range 22 mV divide by 5 40 dB attenuator e Input range 70 mV no division by by 5 40 dB attenuators e Input range 220 mV divide by 5 20 dB attenuator e Input range 700 mV 7 V 70 V and 700 V no division by by 5 20 dB attenuator Input range 2 2 V 22 V 220 V and 1000 V divide by 5 no attenuators 2 Analog Section Detailed Description 2 90 A D Amplifier Circuits 2 91 Refer to Figure 2 8 a block diagram of the A D amplifier circuit The A D amplifier circuit contains the following main circuit blocks Null DAC e Instrumentation amplifier e Switchable active low pass filter A D converter e Frequency counter with switchable low pass filter CPU CPU ene LPF x10 amp x1 INSTRUMENTA AD TION AMPLIFIER
324. ther sections of U25 buffer FPINT and Control line FRNTPNLCS goes directly to the connector P120 Front Panel Assembly A2 The Front Panel assembly operating in conjunction with the Keyboard assembly linked by a cable 15 the operator interface to the 5790A This assembly contains two separate vacuum fluorescent displays Control Display The Measurement Display Each display has its own control high voltage drive and filament switching circuits This assembly also contains clock regeneration refresh failure detect keyboard scanner LED drive and decoding and timing circuitry Connector J1 interfaces with the CPU assembly and the Digital Power Supply assembly via the Digital Motherboard Clock Regeneration Circuitry To minimize EMI electro magnetic interference the Front Panel assembly accepts a low level sine wave approximately 200 mV p p 3 6864 MHz clock from the CPU assembly and converts it to a TTL acceptable level This is done by high speed differential comparator U7A operating on incoming signals 3 6864MHZCLK and 3 6864MHZCLK The output of U7A is the input to U8 and is also inverted by U11B to create the 3 6864 MHz clock signal CLOCK Twelve stage binary counter US divides the 3 6864 MHz clock by eight and U11A inverts the signal to create 460 8 kHz The master clock is further divided by U8 producing 900 Hz signal pin 1 These clocks provide system timing for
325. timing and synchronization signals used by the other ICs Signal DMDBLANK controls the Control Display grid drivers ABCLK and CDCLK control the Control Display anode drivers and OTDBLANK controls the Measurement Display grid and anode drivers Front panel DTACK and interrupt functions and generation of the various chip select and reset signals are also provided by U3 Table 2 6 is a memory map for the front panel Table 2 6 Front Panel Memory Map Nm ip R D0340010 D037FF LED LATCH EN D03400 to D037FF KEYBOARDCS D03800 to 2 43 Control Display Circuitry Control Display circuitry consists of a 26 row by 256 column vacuum fluorescent dot matrix display under the control of PLD U4 four high voltage grid drivers U20 U23 four high voltage anode drivers U16 U19 a filament switching circuit and 1 K X 8 1 KB dual port RAM UI This display is divided into 129 grids alternate grids contain two anode columns lettered B C or D A Grid G129 and column C in grid G128 are not used Each column contains 26 individual anodes IC U4 is an EP900 Programmable Logic Device PLD It provides the timing and control signals for Control Display circuitry The display data written by the microprocessor into the Control Display s dual port RAM U1 is read by U4 and sent serially to the high voltage anode drivers Both the anode and grid drivers are serial TTL level input 3 bit parallel h
326. tors detect an overrange condition Digital control of Wideband circuit then clears relay driver U26 dropping out the input relays to open the input path 2 45 5790 Service Manual Note A detailed circuit description of the A6A2 Input Protection module is provided further on XAIGWASSV QN OL AIHW3SSV 4 QN SLY OL LINDYIO YALNNOO evov HOSN3S SWH S39NVH 1955540 2 0 OZ OL 0 HOSN3S Suo1IvuvdWNOO 39NVH d y ATEVHOLIMS AINO S39NVH H3AAO1 Movadaad 19395450 ZH 08 Z avol 08 AINO SADNVY H3ddn eZ LZ o OZ OL O SHOLWNNALIV ATEaVHOLIMS YOLWNNALLY 08 ZH 08 3ON3Hdd3H NOILO3 1OHd Lvov elu012 eps Figure 2 10 A6 Wideband Assembly Block Diagram 2 46 2 106 2 107 Theory of Operation 2 Analog Section Detailed Circuit Description Input Signal Path for the Upper Four Ranges The following text describes the input signal path from the front panel to the input of RMS sensor buffer amplifier U5 as shown on the block diagram Input signals
327. try A Keyboard assembly provides the user with front panel control of the 57904 It contains six keycap LEDs and a keypad It connects to the Front Panel assembly via a cable The Front Panel assembly provides information to the user on an Measurement Display and a Control Display The Front Panel also contains circuitry that scans the keyboard and encodes key data for the CPU The Rear Panel I O assembly includes digital interfaces for the IEEE 488 bus and RS 232 C Analog Section Overview The guarded analog section of the 5790A contains the following assemblies e Filter A18 e Regulator Guard Crossing A17 e Transfer A10 e A D Amplifier A15 e DAC 16 e Wideband A6 Option 03 These analog assemblies are interfaced to the Analog Motherboard assembly A3 The guarded digital bus generated by the guard crossing portion of the Regulator Guard Crossing assembly controls all analog assemblies except the Filter The Guard Crossing interfaces with the unguarded CPU assembly via a fiber optic link The Transformer assembly together with the Filter assembly and the regulator portion of the Theory of Operation Analog Section Overview Regulator Guard Crossing assembly create the system power supply for all the analog assemblies MEASURE INPUT INTERRUPT BINDING KOSUS TRANSFER ATTENUATORS SWITCH AND PROTECTION MODULE TYPE N RMS CONNECTOR SENSOR
328. und conductor in an power receptle Ground Loop Undesirable current induced when there is more than one chassis ground potential in a system of instruments Ground Loops can be minimized by connecting all instruments in a system to ground at one point Guard A floating shield around sensitive circuitry inside an instrument The guard provides a low impedance path to ground for common mode noise and ground currents thereby eliminating errors introduced by such interference International System of Units Same as SI System of Units the cepted system of units See also units units and derived units Legal Units The highest echelon in a system of units for example the 1990 SI volt Life Cycle Cost The consideration of all elements contributing to the cost of an instrument throughout its useful life This includes initial purchase cost service and maintenance cost and the cost of support equipment Appendices A Glossary of AC DC Transfer Related Terms Linearity The relationship between two quantities when a change in the first quantity 15 directly proportional to a change in the second quantity Linearity Error Linearity Error occurs when the true output vs selected output response curve of a calibrator is not extly a straight line You can measure this type of error by plotting the response curve then measuring how far the curve deviates from the straight line at various points MAP Measu
329. ut which must always be preceded by DC calibration 1 Setup the equipment as shown in Figure 3 8 Connect the 792A without the 1000 V range resistor first 3 21 5790 792 INPUT 1 1000 RESISTOR USE ABOVE 220V ONLY 5790A UUT 792A TRANSFER EXT GUARD STANDARD COAXIAL TEE ONLY NO CABLE BETWEEN 792A AND 5790A Use HEAVY BRAID 500 COAXIAL CABLE OUTPUTHI 5700A CALIBRATOR WITH 5725A AMPLIFIER INT SENSE INT GUARD STRAP FROM GUARD TO GROUND elu030 eps Figure 3 8 5790A AC Calibration Test Setup 2 Setup 5700 as follows so that its internal AC transfers are off 3 22 Calibration and Verification 3 Periodic Calibration a Press the Setup Menus softkey b Press the Special Functns softkey c Press the ACXfer Choice softkey so that ON appears d Press PREV MENU twice e Set the 5700A to 1 V 1 kHz operate Press Intrnl Xfers softkey so that OFF appears The Intrnl Xfers softkey appears only in the 5700A ranges below 220 V and at frequencies below 120 kHz f Press 0 0 Hz ENTER on the 57004 Leave the 5700A in standby The display prompts you for INPUT or 2 Verify that the INPUT1 keycap indicator is lit Press the Proceed With Cal softkey The display changes to Range Cal Step LF 10 Hz Linearity 2 2V SKIP DO LOCKED Apply 2 0V
330. utput with SDL A D range Should be about 0 Use A D to check chopper frequency at fast rate 5 9 5790 Service Manual Possible errors include Chopper 0 dB High Failed Chopper 0 dB Low Failed Chopper 20 dB Failed Chopper 40 dB Failed Chopper 60 dB Failed Chopper FAST Failed Chopper FAST Frequency Failed Chopper SLOW Failed Chopper SLOW Frequency Failed elu061 eps These errors all suggest a fault on the A15 A D Amplifier assembly Use an oscilloscope in addition to a DMM to troubleshoot the fault Check the chopper input through chopper to SDL line to U24 Test Step PROT Protection Tests part of the protection circuitry on the transfer assembly The software can only test the section that detects multiple input relays being closed The spark gaps that detect over voltage can not be exercised The test proceeds as follows 1 Program the hardware to close RL Y3 IN1 High to KV Rnet INI High to 220 V Rnet 2 Check trip status The relays should have tripped The error from this test 1s Error Code 3009 A10 Transfer Protection Check Failed elu062 eps This error indicates a possible fault in the protection circuit on the A10 Transfer assembly Test Step OVLD Overload Tests the sensor input overvoltage circuitry This test proceeds as follows 1 Configure per 2 2 V range no inputs 2 Setup with chopper connected to sensor 3 Program DAC to 5 0 V Check tr
331. y driver latch U25 when data is strobed in by bus line PB6 Relays K1 K4 K5 and K6 are controlled by driver latch U26 with strobe PB7 FETs are controlled by latch U20 and strobe Switches are controlled by U21 and strobe PC2 A6A2 Input Protection Module The A6A2 Input Protection assembly drops out the Wideband input relays the input signal reaches approximately 14 V in amplitude Opening the input relays protects Wideband circuits from damage The instrument drops out of Wideband mode and activates the INPUT 2 binding posts whenever the A6A2 circuit trips The A6A2 circuit is composed of dual comparator U1 transistors Q1 and Q2 zener diodes and VR2 and associated components Zener diode VR1 biases the positive input at pin 1 to 12 Transistor 1 is off until the Wideband input signal reaches about 14 V which causes diodes and CR31 CR24 and CR25 on the Wideband board to start conducting When 1 conducts about 5 mA it turns on and starts to raise the voltage at comparator U1 pin 5 The other input of the comparator at U1 pin 4 is biased to 0 5 V When the input at U1 pin 5 exceeds 0 5 V the comparator output turns on and drops the voltage on the output connector pin 11 to 0 V Zener diode VR2 biases the negative input at pin 3 to 12 V Transistor Q2 is off until the Wideband input signal reaches about 14 V which causes diodes 5 and CR30 or CR14 and CR15 on the Wideband board to start conducting
332. y to U24 Test Step LOOPFILT Sensor Filter Tests slow mode sensor loop filter settling time Fault 3019 A10 Transfer Sensor Loop Settling Transfer board configured in 1000 V range no inputs Connect sensor output to RCL Positive instrumentation amplifier input to RCL negative to RCOM Configure DAC to driver chopper Sensor loop filter in slow mode Set DAC to 2 0 V Let the sensor output settle Measure sensor output with x1 A D range Switch chopper to be driven by DAC divided by 5 0 4 V Let it settle Again switch chopper to be driven by DAC directly and then immediately take 8 sample A D reading Compare this reading with first settled reading 5 13 5790 Service Manual 5 22 5 23 5 24 Test Step WOVLD Wideband Overload Tests the sensor input overvoltage circuitry Configure per 2 2 V range no inputs Set up with chopper connected to sensor Program DAC to 0 5 V Check trip status Should indicate overload The error from this test 1s Error Code 3016 A6 Wideband Overload Check Failed elu069 eps This error indicates that the fault is probably on A6 Wideband assembly Check that indicated voltage DC from chopper appears on the A6 Wideband assembly to the input of the sensor Check the overload detection circuitry Test Steps W7V through W2 2MV Wideband 2 2 mV Range Tests each range to the point where the chopper is injected The test proceeds as follows 1 Configure instrument per norm
333. z 100 kHz 64 68 85 100 kHz 300 kHz 140 150 180 300 kHz 500 kHz 370 390 490 500 kHz 1 MHz 1100 1200 1500 10 Hz 20 Hz 55 61 62 64 20Hz 40Hz 19 30 32 40 40 Hz 20 kHz 15 23 25 34 220V 20 kHz 50 kHz 24 30 34 49 50 kHz 100 kHz 66 69 83 100 kHz 300 kHz 160 170 220 300 kHz 500 kHz 410 480 680 10 Hz 20 Hz 55 62 63 65 20 Hz 40 Hz 19 31 33 41 700 V 40 Hz 20 kHz 19 24 25 31 20 kHz 50 kHz 100 110 140 50 kHz 100 kHz 390 500 850 10 Hz 20 Hz 55 62 63 65 20 Hz 40 Hz 19 31 33 41 1000 V 40 Hz 20 kHz 19 24 25 31 20 kHz 50 kHz 100 110 140 50 kHz 100 kHz 390 500 850 1 1 9 5790 Service Manual Secondary Performance and Operating Characteristics 24 Hour AC Temperature Coefficient T Voltage Range Frequency Range 10 to 40 M 2 d Eam 2 Peak uV ppm 10 Hz 20 Hz 0 4 50 50 20 Hz 40 Hz 0 4 50 50 40 Hz 20 kHz 0 4 50 50 22mV 20 kHz 50 kHz 0 4 50 50 gt 10 50 kHz 100 kHz 0 8 75 75 100 kHz 300 kHz 1 5 100 100 300 kHz 500 kHz 3 0 150 150 500 kHz 1 MHz 4 5 200 200 10 Hz 20 Hz 0 4 15 15 20Hz 40Hz 0 4 15 15 40 Hz 20 kHz 0 4 15 15 7 mV 20 kHz 50 kHz 0 4 15 15 gt 10 50 kHz 100 kHz 0 8 25 25 100 kHz 300 kHz 1 5 60 60 300 kHz 500 kHz 3 0 80 80 500 kHz 1 MHz 4 5 125 125 10 Hz 20 Hz 0 4 5 5 20 Hz 40 Hz 0 4 5 5 40 Hz 20 kHz 0 4 5 5 20 kHz 50 kHz 0 4 5 5 gt 10 22 50 kHz 100 kHz 0 8 8 8
334. z 1200 3000 3600 No spec 0 022 0 02 10 Hz No ST 0 m 2 A ui m ooe oo ww pe o0 roo mw ie __ ___ oreo m o0 w re 58 m sow m so 5 ooz ove foo ass 48 3 44 Calibration and Verification Verification Table 3 13 Test Record for Main Input Verification cont Voltage V Max Uncertainty AC Source 0 022 300 kHz 0 022 500 kHz 0 022 1 MHz 0 07 10 Hz 0 07 20 Hz 0 07 100 Hz 0 07 1 kHz 0 07 10 kHz 0 07 20 kHz 0 07 50 kHz 0 07 100 kHz 0 07 300 kHz 0 07 500 kHz 0 07 1 MHz 0 22 10 Hz 0 22 20Hz 0 22 100 Hz 0 22 1 kHz 0 22 10 kHz 0 22 20 kHz 0 22 50 kHz x NIN N N 5790A Range 0 22 100 kHz 0 22 300 kHz 0 22 500 kHz 0 22 1 MHz 10 Hz 20 Hz 100 Hz 1 2 10 kHz mo meo um 210 90 Day Absolute AC Error Absolute AC Error Measured Absolute AC Error 2 Yr AC DC Error Spec ppm Measured AC DC Error PPM 145 153 3 3 45 5790 3 46 Table 3 13 Test Record for Input Verification cont Voltage V Frequency AC Source Max iE Absolute AC Error Spec ppm Absolute AC Error Measured Absolute AC Error PPM 2 Yr AC DC Error Spec ppm Measured AC DC Error PPM 20kHz k

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