Home

Keithley -- 160B - subfrequenz.net

1. 2N5139 TG 66 2 Q105 PNP TOSl06 v c 5 a ie D Te ee T FAIR 2N5140 TG 110 1 0106 NPN 106 FAIR 2N3565 TG 39 1 0201 PNP TO 106 FAIR 2N5139 TG 66 atte Q202 0 106 FAIR 2N4355 TG 90 4 Q203 PNP TO 106 Cases a s soes FAIR 2N4355 TG 90 0204 PNP TO 106 Case 20 FAIR 2N4355 TG 90 Q205 TO 106 Case FAIR 2N4355 TG 90 i Q206 NPN 70 92 MOT 2N5089 TG 62 2 Q207 NPN TO 92 MOT 2N5089 TG 62 RESISTORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Wty RIGL ika 10 0 25 Comp 4 96 5 CB 102 10 R76 1K 4 R102 499kQ 0 52 O 5W MEF b oh 4 on otn n ng DALE MMF 1 2 T9 499K R171 499K l R103 1 8k2 10 0 25 0 A B CB 182 10 R76 1 8K 1 R104 499kQ 14 0 12W DALE MFF 1 8 T9 499K R177 499K 2 R105 O 5W BECK 7 2PMR 1K RP97 1K 2 R106 5 8kQ 1 0 128 4 5 6 o DALE MFF 1 8 19 5 8K R177 5 8K 1 1107 1000 1 0 12W woe oe al Ea 6 DALE MFF 1 8 T9 100 R177 100 1 R108 499kQ 12 0 12W 2 DALE MFF 1 8 T9 499K R177 499K E R109 475kQ 12 O 12W er we on on Uw n DALE MFF 1 8 T9 475K R177 475K 1 R110 500
2. 72PMR 50K RP97 50K 1 R111 56 2 0 1 0 120 IRC CEA TO 56 2K R88 56 2K 1 112 100 0 1 0 120 IRC CEA TO 100K R88 100K 1 R113 32 4k0 1 0 120 ce 8 e s os oe on o om oa o on on IRC CEA TO 32 4K R88 32 4K 1 RI14 S kQ ZW 4 5 0 RO Cw 065 CLARO 73JA 50KQ RP108 50K 1 R115 Imo 1 0 12W Cu ee o n on n IRC CEA TO 1MQ R88 1M 1 R116 56 10 28 Comp s ssa aoa 60 5 3 5 ee A B HB 563 10 R3 56K 2 R117 56k 10 2W Comp p s 0 on on on 563 10 R3 56K R118 22 0 10 0 25W Comp s 0 A B 223 102 R 6 22K 3 R119 3309 10 0 25W Comp gt CB 331 10 R76 330 2 8120 3302 10 0 25W Comp s CB 331 10 76 330 55 R121 2kQ 0 5W Var M BOURN 32991 2K RP104 2K 1 R122 9 0k2 0 1 0 12W DALE MFF 1 8 9 0K0 R 168 9 0K 1 8123 10 0 1 0 12 10 9 R88 10K H R124 2 2 0 10 0 25W Comp xs A B CB 222 102 R76 2 2M 2 R125 1 0 10 0 25W Comp CB 102 10 R76 1K R126 2 2 0 10 0 25W Comp CB 225 10 R76 2 2M R127 5 6k2 10 0 25W Comp s A B CB 562 10Z R76 5 6K 1 R128 22kQ 102 0 25W Comp CB 223 10 R76 22K R129 22 0 10 0 25W Comp 223 10 R76 22K
3. SOM 97 9 6631 0 SAHO NI S30mw HOISISSH Nv 0 lt gt xr d 4 i Z of 153404 e soir Az 7 7 oils 222 v eu SE 5 uy 73 H f 7 22 5 35 peg em n Wa 4 4 ey LE POST EPS an 1 d 3 2wd022v INOZ dib e occ 1 m 4 ate 2 091 I AA z 3 _ _ e 5 o3 y B i Gawnd Sus 3 1019 1010 10 gt 5 ana ru A lt s 6 ie x66 L v ei 256 I I A 35N34343H SWHO t di i 43d AN OO I s i d 972918 Z914 9019 r n 0215 i 29 2 359692 9195 Kes 9 AZO 335 5078 guaz 2 3N02 t 12 e fest me lt 4 y y Y T nalno Al 21 WoO cyn sea 215 J saly 0832 ioe ITem HO Valois SNAIL iano 12601 Quien s 125330 m CN ZANE TE REUS RES SLE IET beat ae eee ELLA 26590 EZE W u rr w 0 1 gt r H
4. 6 IC 103 KEITHLEY m IC 102 KEITHLEY PART FIGURE 36 Case Outline Integrated Circuits 56 1174 MODEL 160 REPLACEABLE PARTS KEITHLEY He NO 104 KEITHLEY CANT NO IC 105 ANN ik fO i K FIGURE 37 Case Outline Integrated Circuits 1174 REPLACEABLE PARTS MODEL 1608 108 KEITHLEY PART NO KEITHLEY PART NO TG 94 LEAD DESIG TO 92 8 6 TO 92 LEAD DESIG TO 5 69 6 j TO 5 LEAD DESIG TO 106 KEITHLEY PART NO TG 77 D D 5 9 R 110 5 E TO 106 BOTTOM N CHANNEL FET BOTTOM VIEW FIGURE 38 Case Outline Transistors 58 1174 MODEL 1608 REPLACEABLE PARTS 111 135 FIGURE 39 Case Outline Thick Film Networks 1174 59 REPLACEABLE PARTS MODEL 160B KEITHLEY PART NO TF 36 KEITHLEY PART NO TF 37 i8 7 6 5 KEITHLEY PART NO TF 39 16 15 141 113 12 11 10 9 waga FIGURE 40 Case Outline Thick Film Network 60 1174 MODEL 1608 REPLACEABLE PARTS FIGURE 41 Case Outline Custom 1 51 1174 61 REPLACEABLE PARTS MODEL 1608 COMPONENTS LOCATED ON PC 349 Circuit Location Circuit Location Circuit Location Circu t Location Desig Code Desig Code Desig Code Desig Code C101 F 5 P102 1 4 8118 2 R205 C 8 C102 F 4 P103 J 3 R119 F 1 R206 B 7 C103 1 104 H 2 R120 E 2 R208 H 7 C104
5. WARNING The Medel 16028 Digital Output is not isolated from the 1608 inpuc high and low If the Model 1602B Digital Output is installed the digital input output lines will float at the same potential of the Model 160B input high and low never be grounded while the Model 1608 is floated 0976 Any equipment connected to the Model 1602B must also float sent at the digital output lines if the Model 1608 is floated above safety ground Hazardous voltages could be pte The Model 1602B must OPERATING INSTRUCTIONS FIGURE 16 3 15 HOW TO USE MODEL 16028 DIGITAL OUTPUT a General The Model 1602B Digital Output provides binary coded decimal BCD outputs and several control inputs This accessory is available either factory installed or field installable The Model 16028 consists of a single printed circuit board PC 352 with input and integrally mounted output connector and an output mating connector with hood b Installation of Model 1602B The Model 1602B is installed internal to the Model 160B and is power ed by the Model 160B line operated power supply NOTE It is not intended that the Model 1602B be used simultaneously with the Model 1688A Battery Pack To use the Model 16028 the Model 1688A must be removed and set aside It is possible however for the user to make his own wiring modifications so that the Model 1688A Battery Pack can power the Model 160B while located outside the Model 1608 Conn
6. 3AG 1 8A 105 125 NORM 117 SLO BLOW 195 235 Low 234 INTERNAL 210 250 NORM 234 CAUTION 234 VOLT LINE MAY CAUSE DAMAGE WITH 117V SELECTED Low NORM 117 234 SWITCHES SHOWN FOR OPERATION FROM 105 125V LINE FIGURE 5 Rear View Showing Line Switches 1174 3 MODEL 160B INITIAL PREPARATION TIA ONISN 38O33H Zt OE VE AXTHIIX Us Afi STI3O 4 AH3LIVS V889L Model 1688A Rechargeable Battery Pack FIGURE 6 Exploded View of Model 1608 1688 FIGURE 7 0976 4 MODEL 160 INITIAL PREPARATION TO 205 BATTERY FUSES F203 F204 SPACER 4 PLACES CAUTION DISCONNECT LINE CORD BEFORE OPENING THE TOP AND BOTTOM COVER LINE VOLTAGE ON THE CHASSIS REPRESENTS A SHOCK HAZARD FIGURE 8 Installation of Battery Pack 0976 5 INITIAL PREPARATION SECTION 2 2 1 GENERAL This section provides information needed for incoming inspection and preparation for use 2 2 INSPECTION The Model 160B was carefully in spected both mechanically and electrically before shipment Upon receiving the instrument check for any obvious damage which may have occurred during transit Report any damages to the shipping agent To verify the electrical specifications follow the procedures given in Section 6 2 3 PREPARATION FOR USE The Model 160B is shipped ready to use The instrument can be
7. e E V ome 242494 P110 Spins xw x he dete KI idis C8 339 3 2111 Male 4 pine 0 250 owe 6 C8 339 4 P112 Note Usedes ay SAG We ON vu REESE P113 Not 4 4 114 Male Pin 29 tras emi EA UR oa KI 24249A P201 Cable Assembly to Model 16028 soa ween KI Pis 26424A 2 1 P202 Cable Assembly to Display Board KI vd s 26424A 1 1 P203 Receptacle Male 3 pins beg Wm Uu MOLEX 239 CS288 3 1 P204 Line Cord 3 conductor 5 FT 9 IN CMe pA ch amus de cede KI 0 9 1 205 Receptacle Male pins MOLEX A2391 4A C3288 4 1 P206 Male 325 4402 he ae 5 339 8 2 207 8 e lt e s coo oy o reso KI P CS 239 8 T P208 Male Pin 2 ace nies a 4 a Boe Eus KI 59905 24249 2 48 0976 MODEL 160 REPLACEABLE PARTS TRANSISTORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part Qty Q101 PNP Power Type 10W TO 5 Case RCA 2N5416 TG 105 1 0102 Dual P Chan MOS FET TO 77 Case GENI 955 004 TG 94 1 0103 Chan JFET 110 Case so INTER 4392 TG 76 1 0104 PNP 0 106 Case
8. th rd i i vesc Yeyezor Y yeas Y Y F203 i oH 5 U206 4 9 v 2 n BATTERY PACK p I 9290 OR 1 gt gt gt m wOCEL 16588 1 OPTIONAL L 1 gt lt gt 5 R216 l F204 1 OECK A 5263 DECK B 7 cr 17 2 OFF J P206 377206 9296 AUN 04 00 0 09 7 IN our 862 ouTeuT 80280 1425 J P207 a 2268 CONNECTS 70 i303 SEE 26654 207 i 525 o 206 Hic Ti amp o o J P20 amp a HIGHEST REFERENCE UNUSED Ip 12v DESIGNATIONS REF DESIGNATIONS C207 CR204 105204 F204 lt 205 2204 8 TP201 Ed 1 SCHEMATIC DIGITAL LOGIC DISPLAY SUPPLY KEtTHLEY forse RIK INSTRUMENTS eae a ee 8 gt E F G H l X Iu aoesse _ zu ee feats lt T N3183 ANO2 7 ARI a a ew eos sa gt GOW oz cer CT 1710195 Pell ty Cac s 2 16 5 4 7 r 9 2 lt ees 4 o pose oie eo u 0 4 amp s
9. 104 3 0311 Quad Clocked Latch 16 DIP e RCA CD404 2AE IC 104 U312 Quad Clocked Latch l6 pin DIP eee RCA CD4042AE IC 104 54 0313 Hex Buffer 16 RCA CD4050AE Ic 107 1 0314 Quad 2 input NOR 14 DIP 1 s RCA CD4001AE 108 gc U315 Quad 2 input NOR 14 DIP cue ne Das RCA CD4001AE 16 108 0316 Quad 2 input NOR 14 pin DIP Soire y RCA CD4001AE 16 108 1317 Quad 2 input NOR l pin DIP 422 RCA CD4001AE 108 1318 Quad 2 input NOR l pin nm RCA 040014 IC 108 U319 Quad 2 input NAND l pin 4 ea es RCA CD4011AE 102 1320 Quad 2 input NAND l pin S 0 RCA CD401 LAE 102 53 1174 REPLACEABLE PARTS MODEL 160B KEITHLEY PART NO IC 24 KEITHLEY PART NO 47 GATE KEITHLEY PART 53 KEITHLEY PART NO 60 FIGURE 34 Case Outline Integrated Circuits 54 1174 MODEL 160B REPLACEABLE PARTS KEITHLEY PART NO 71 KEITHLEY PART NO IC 77 B 71 61 5 8 171181 5 E aT I Ts 14 DI 121 IST OFFSET KEITHLEY PART NO IC 99 al 141 S OUTPUT e OFFSET 1174 55 REPLACEABLE PARTS MODEL 1608 KEITHLEY n NO BUFFER DRIVER 100 KEITHLEY deal hid IC 101 f 204542222240 0000066 0
10. 3 3 2 8 v _ 105 Ac CiO7 RHS Wig Mii 9lH 1010 10 42 8 amp _ 2 O28 CO Zu 2028 DAS 020 16257 _ 9029 RM c202_ 7 TP2020 Em P203 205 PC 3459 gt WAV OES COMPONENTS LOCATED ON PC 352 Td Circuit Location Circuit Location Desig Code E Desig Code E C301 E 1 P301 ac C302 C 7 U306 CR306 C303 C 6 Q301 E 8 ESSE 3 C304 C 4 9302 8 Blo 8307 C305 D 3 0303 7 mia CR303 0304 E CR301 F 2 Q305 E 7 2 U303 0304 9319 0320 CR3OS CR302 F 2 Q306 E 7 CR304 CR303 F 2 0307 6 CR304 F 2 0308 E 6 J302 CR305 F 2 Q309 E 6 CR306 F 1 Q310 E 6 x CR307 F 2 0311 6 3 m CR308 F l Q312 E 5 P301 USOS 0318 CR309 1 0313 5 C305 CR310 D 1 0314 E 5 0315 5 2302 G 2 Q316 E 5 4 A e 9308 U3I7 R303 0377 Sia Qt 9367 Circuit Location Circuit Location R309 5V e e Desi Code Desi Code ___ 5 guo 0314 0317 E 4 U303 A 1 a33 E 0318 4 304 1 5 osi2 0 0319 E 4 1305 3 0816 xd 0320 E 4 U306 E 1 R306 0307 B 4 6 2 7 5 a R301 E 2 U308 C 4 9309 R302 E 2 U309 D 3 Q308 R303 D 4 U310 C 7 R304 D 1 U311 C 6 R305 D 7 U312 C 5 PEEL 0315 0383 qaos R306 D 5 U313 D 6 7 gtn
11. 109 and 1000 ranges the Model 160B is to be zeroed on the 12 range The zeroing is accomplished by shorting the test leads together and adjusting the display for a flashing and 0000 By zeroing the instrument in this manner lead resistance of 200 milliohms minimum can be compensated for The instrument must be rezeroed on the 10 range each time a different set of test leads is used Before making measurements right at the in put terminals test leads used the instrument should be zeroed on the 19 Range after placing short such as of copper wire across the binding posts Copper leads and clips are best for making measurements on the 10 Range because the voltage drop across 10 resistor is only CAUTION Care should be taken when making resistance measurements in circuits which may have volt ages on capacitors etc or where line volt age is present Although the Model 160B is fully protected against accidental voltages up to 250V rms in resistance function if higher voltages are applied damage may occur 1174 MODEL 1608 OPERATING INSTRUCTIONS FUSE SHOWN TWICE ACTUAL SIZE FIGURE 11 Location of Protection Fuse 3 7 HOW TO MEASURE CURRENT The Model 1608 measures dc current in nine ranges 10 100 luA 10uA 100A lmA lOmA 100mA and 1000mA a How to Select Range Function and range is selected by rotating the Range Switch to the appro pria
12. Ground 13 long SC 33 Model 160B specifications except 1 150 pico 6 Clip Alligator Ground AC 10 farads input capacitance 2 0 5 ampere maximum 7 Insulator Black 11 current 3 0 3 ohms resistive offset 4 20 micro 8 Cable 40 long sc 30 volts thermal offset 9 Strain Relief 18676 10 Shield 25128A AC MODE Voltage only RANGE 250 volts rms maximum TRANSFER ACCURACY 3 of reading 0 1 volt 45 Hz to 45kHz into a 10M 107 load Peak respond ing calibrated in rms of a sine wave INPUT IMPEDANCE 0 5 megohm shunted by less than 20 picofarads MAXIMUM OVERLOAD Peak ac plus dc must not exceed 400 volts CONNECTOR Shielded Banana Plug DIMENSIONS WEIGHT 6 in long x 3 4 in diameter 150 x 20 mm 3 ft 1 m cable net weight 1 4 pound 0 1 kg MAINTENANCE Since the probe assembly should provide good service with normal handling no maintenance is usually nec essary The probe body Items 2 and 3 is fastened together at the factory using a special solvent Therefore the probe should not be d sassembled If repair is necessary contact the Keithley Represen tative in your area ELECTRICAL PARTS LIST See schematic 24669C Circuit Mfr Mfr Keithley Desig Description Code Part No Part No J101 Banana Plug 2 req d JOHN 108 750 2 2 5101 Switch AC DC KI Special SW 334 C101 Capacitor 0 047yF STAND M2W F 0 047 amp uF C197 047M C102 Capacitor 0 1 uF POT MWlA O luF C86 1M D1
13. T2 0312 during The Overload and Polarity lines are latched by Dual D Type Flip Flop U308 th s fl p flop s enabled dur ng TI The 1 x 103 Overrange line is latched by one sec tion of Dual D Type Flip Flop U309 and is enabled during the TO interval All the T line signals are inverted by a Quad 2 Input NAND gate U307 A B C and D Then the inverted signals are shaped into pulses by R C networks 10k and 470pF the Quad Latches data is transferred from input to output while the enabling pulse is low latching occurs on the positive going edge of the pulse In the p Flip Flops data is transferred from input to output only during the positive going transition of the enabling pulse Output Data Buffers The data buffers consist basically of five Quad 2 Input NOR gates U314 through U318 driving twenty open collector NPN transistors 0301 through 0320 The 10 resistors in series with the transistor bases are located in thick film resistor networks The output transistors have a very high current gain 400 minimum at 10mA collector current this allows them ta be driven into satura tion even at the low base currents that the CMOS NOR gates can supply The output data lines are speci fied to be at a voltage level less than 40 5 volt while sinking 15 milliamperes d Strobe Circuit Hex Buffer 0313 is used to control five groups of data lines and also to control Flag Fla
14. The voltage induced due to magnetic flux is propor tional to the area enclosed by the circuit as well as the rate of change of magnetic flux For example the motion of a 3 inch diameter loop in the earth s magnetic field will induce a signal of several tenths of a microvolt One way to m nimize magnetic pickup is to arrange all wiring so that the loop area en closed is as small as possible such as twisting in put leads A second way to minimize magnetic pickup is to use shielding as described in Section 3 12 12 MODEL 160B 3 11 AC ELECTRIC FIELDS The presence of electric fields generated by power lines or other sources can have an effect on instrument operation AC voltages which are very large with respect to the full range sensitivity could drive the input amplifier into sat uration thus producing an erroneous DC output At line frequency or twice line frequency the instru ment is capable of rejecting AC voltages whose peak to peak amplitude is equal to the full range DC sen sitivity on the l00mV through 1000V ranges This level of interfering AC signal will produce no more than 1 digit error On the ImV 10mV Ranges the instrument can reject line frequency and twice line frequency signals whose p p amplitude is equal to 10 times the full range sensitivity For example on the lmV Range a LOmV p p 50 Hz signal will produce no more than luV 1 digit DC error Peak to peak AC voltages greater than 1X the full ran
15. state The value will depend on the capacitive coupling among wires in the cable and to other circuitry external to the Model 1608 16025 For operation with 5 volt power supplies a value of 5k to 10 is usually sufficient and the mini mum value is about 3002 The Model 1602B printed circuit board ia designed so that pull up resis tors can be mounted on the board itself rather than added externally One end of the pull up resistors can then be connected to an external power supply at pin 18 of the 37 pin output con nector J302 The pc board spacing is designed for 1 4 watt carbon resistors 18 16028 interfaced to a l6 bit computer the 3 BCD digits may be presented to a l6 bit data re gister in the computer by setting lines 25 5 24 to logic 0 at a given time If the DP overload polarity and 1 x 10 outputs are wired TABLE 3 7 Model 1602B Connector Pin Identification Not Used Not Used FLAG RESET BCD HOLD Not Used Not Used DISPLAY HOLD STROBE ST 6 STROBE ST 2 STROBE ST 3 STROBE ST 5 STROBE ST 1 LO STROBE ST 4 DP 3 100 0 DP 2 10 00 DP 1 1 000 FLAG FLAG POLARITY OVERLOAD DATA DATA 8 x 102 DATA DATA 2 x 102 DATA DATA 8 x 101 DATA DATA DATA DATA DATA DATA DATA EXT VOLTS Not Used Not Used gt Ov Un CO iS 103 102 102 101 101 109 x x x X x lt x 1174 MODEL 160B OPERATING TNSTRUCTIONS TABLE 3 8 Model 1602B Output Connector Line
16. 100 1 8 0 01 ESI 622 10 1000 1 48 0 0252 D Current Source lmA lOmA 100 1 0 02 Fluke 3824 Resistance Source 12 8 0 17 General Radio 1433 H 100 8 0 04 1002 1K2 LOKa LOOK 1 LOM 0 02 F Ohmme ter 1002 0 4 Keithley 168 10M9 8 0 3 Resistance Source 1085 0 25 Welwyn 14 108 0 25 H Resistance Source 1092 1 Welwyn M51 109 1 resistor in shielded enclosure 35 0976 MAINTENANCE MODEL 160B TABLE 6 2 5 Verify that the Model 160B reading is within Summary of Battery Voltage Levels at Test Points tolerance stated in Table 6 4 for 1 0 10k 100 1 0 and 10 0 ranges Test Recharge Batteries Point Range Normal If Below Tested 6 Connect Resistance Source C A 2 5 to 9V 4 8V 2 5 29 7 Verify 100 range B 7V to 10 5V 8 4 7 30 8 Connect Resistance Source H 9 Verify 1000 range b Input Resistance Check TABLE 6 4 1 Select LOOOV range Accuracy Check for Resistance 2 Measure input resistance using Ohmmeter F Source Source Display Tolerance Input Accuracy Reading on Reading 3 Resistance should be 10 megohms 14 LQ 0 1 1 000 2 5 digits c Voltage Accuracy Check 10 9 0 04 10 00 2 4 digits 100 2 40 02 100 0 9 4 digits 1 Select range 0 022 1 000k2 4 digits 10k2 0 022 10 00k2 4 digits 2 Apply a short low thermal copper to the 100 0 0 022 100 0k2 4 digits input terminals 1 9 0 022 1 000M t4 digit
17. 12W MtF Sie oup T i DALE MFF 1 8 10K R168 10K R150 100 0 0 12 0 5W s o n P DALE MFF 1 2 100K R169 100K R151 IMR 0 1 0 59 MtF a s 8 wo ca a DALE MFF 1 2 1M R169 1M R152 10 0 0 12 0 55 4 DALE HMF 10M R174 10M 1 R153 99 0 12 IW Comp HIMEG 60 99 R 235 99M 1 R154 910 0 10 0 5W Comp m or RI IRC 1 2 910 R230 910M 1 8155 1 74 0 14 0 120 aru IRC CEA TO 1 74K R88 1 74K i R156 Not Used W R157 27kQ 10 0 259 Dos Eee Gs gl ta 273 10 R76 27K 1 R158 47kQ 10 0 25W Comp CB 473 10 R76 47K 1 R159 Thick Film Network 4 pins m XV ECL IRC 005 TF 34 1 R160 Thick Film Network 5 pins 444 40 003 35 1 R161 Thick Film Network 8 pin DIP E E ue CTS Special TF 36 1 R162 Thick Film Network 14 pin DIP gf va tales ES CTS Special TF 37 l R163 100 1 0 12W IRC CEA TO 10 R88 10 1 8201 8 7 0 104 0 257 Comp P ren A B 472 102 R76 4 7K l R202 2 2k2 10 0 25W Comp CB 222 10 R76 2 2K l R203 lkg 10 0 25W Comp 102 10 R76 1K R204 3 3 0 10 0 25W Comp 4 CB 332 10 R76 3 3K R205 12 7k9 1 0 124 Q E 4 EP IRC
18. 28 pin DIP x FAIR Special LSI 2 1 U202 Timing Circuit SIG NE555V IC 71 i U203 Quad 2 Input Pos NAND 14 pin TEXAS SN7401N 16 47 i U204 Hex Buffer Driver 14 DIP TEXAS SN7417N 101 0205 Transistor Array l pin DIP RCA CA3086 53 0206 Transistor Array l pin DIP RCA CA3086 53 0207 5V Regulator 70 220 Case MOT 7805 1C 93 1 0208 12V Regulator TO 220 Case FAIR UGH 812393 60 1 ZENER DIODES Circuit Mfr Mfr Keithley Desig Description Code Desig Part Qty VR101 Zener 6 4V 400mMW DICK 144577 DZ 51 1 VRLO2 2 0V ee Aa GE Ge SE SUN TEXAS IN702A DZ 33 1 51 0875 REPLACEABLE PARTS MODEL 1602B MODEL 1602B DIGITAL OUTPUT 300 SERIES 352 CAPACITORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty C301 250 MER 596 ee AMPRX C280AE PLOOK 178 0 1 1 302 470 1000V 0 CENLB DD 471 C64 470P 4 C303 470 1000V CENLB 471 C64 470P C304 470pF 1000V CerD CENLB DD 471 C64 470P 5 C305 470 1000V CerD CENLB DD 471 C64 470P 22 DIODES Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty CR301 Rectifler 75mA 75V wes e
19. 70 12 7 R88 12 7K 1 R206 12 0 124 44 42 IRC R88 1K 1 R207 1500 10 0 25 Comp CB 151 10 876 150 2 R208 1500 10 0 25W Comp oe A B CB 151 10 R76 150 R209 1800 10 0 25W Comp CB 181 10 876 180 3 R210 1800 10 0 25W Comp KS a CB 181 10 R76 180 R211 1802 10 0 25W Comp 6 05 CB 181 10 876 180 T R212 6 04 0 1 0 12W 3 IRC CEA TO 6 04K R88 6 04K 1 R213 4 02k0 1 0 12M MtF an E IRC CEA TO 4 02K R88 4 02K 1 R214 10 0 10 0 25W Comp gt EM 103 10 R76 10K 2 8215 1069 10 9 25W Comp 444 n CB 103 10 R76 10K R216 40 2 Q 12 0 12W IRC CEA TO 40 2 R88 40 2 1 8217 Thick Film Network l6 pin DIP bag cts 900 6 TF 30 1 8218 Thick Film Network 16 DIP CTS 900 7 TF 31 SWITCHES Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty 5101 Rotary Switch RANGE 4 4 5 373 1 Knob RANGE En zm KT 44 KN 33 i 5201 Slide Switch DPDT Line Voltage wd ov ce ve C W GG350PCDPDT SW 318 2 202 Slide Switch DPDT Line Voltage GG350PCDPDT SW 318 5203 Rotary Switch Power Selector TE KI 50 374 1 Knob
20. DIGITAL OUTPUT CONNECTOR J302 MODEL 16028 DIGITAL OUTPUT N N PC 352 SIDE VIEW OF CONNECTOR INSTALLATION P208 PC 349 P301 FROM PC 352 MODEL 1608 PC 349 P208 PINE FIGURE 17 Installation of Model 1602B 1174 OPERATING INSTRUCTIONS OPERATING INSTRUCTIONS MODEL 160 OOOOCCCCTTQOCCOCOCOQCOC FIGURE 18 Rear Panel Digital Output Connector 4 Output Data Lines BCD 1 2 4 8 open collector a The open collector configuration can be positive logic represents each of 3 digits overrange used to connect multiple outputs to one input of digit overload decimal position and polarity a data processing system For example if the 1 Open collector Output The output data buffers of the Model 1602B consist of CMOS NOR gates driving individual open collector transistors main feature of open collector outputs is the ability to interface with a variety of data processing equip ment types including printers and computers The open collector output operates in either a saturated low impedance state or an open high impedance state It is compatible with many types of logic including TTL DTL RTL and CMOS The Model 16028 output lines can operate at voltage levels up to 20V and hence can interface directly with CMOS circuits operating with 15V supplies In most cases pull up resistor is needed to define the open or logic I
21. F204 are plug in types and are lo cated on pc board PC 349 as shown in Figure 8 Replace with 1 ampere 3AB slo blo Keithley Part No FU 28 MODEL 160B INITIAL PREPARATION b How to Operate From Battery Power To operate the Model 1608 from batteries the Model 1688A Re chargeable Battery Pack must be installed The Model 1688A can be either field or factory installed The batteries in the Model 1688A may need recharging be fore their first usage to power the Model 160B NOTE The Model 1688A Rechargeable Battery Pack can be installed within the Model 160B chassis at any time However if the Model 16028 Digital Output is already installed the Model 1688A cannot be used simultaneously 1 to Install Model 1688A Rechargeable Bat tery Pack The batteries furnished with the Model 1688A come already installed in the battery pack The battery pack includes 7 rechargeable cells 1 2 3 AMP HR and 1 rechargeable pack 16 8V If batteries need to be replaced or re installed be certain to observe the proper polarity of indi vidual cells as shown in Figure 6 To install the Model 1688A Battery Pack turn the instrument over so that the bottom cover faces up Loosen four slotted screws on the bottom cover as shown in Figure 4 A chisel blade screwdriver is requirec to loosen the slotted screws Turn over the in strument with top cover facing up taking care to hold the top and bottom covers together Carefu
22. Flag Reset C rcuit The Flag Reset circuit uses three gates out of a Quad 2 Input NAND gate 0319 and D Flip Flop out of a Dual 5 Type Flip Flop U309 This circuit allows Flag Flag to be reset at any time when Flag Flag is at logic 1 logic 709 Operation is as follows When Timer U306 is triggered by CN See Section e above its output goes to logic 1 logic 1 at the 51 input of U309 sets 01 of 0309 to logic I 01 coa trols the output of NAND gate U319B when Ql is logic 1 U319B re inverts the inverted output of Timer U306 so that the Flag signal is present at pin 4 of U319B When 01 is at logic the out put of U319B pin 4 is high regardless of what the Timer is doing 01 is set to logic 0 by a sipnal on the Flag Reset line A high to low transition on the Flag Reset line produces a low to high transition at the Cl clock input of U309 When this occurs a logic 0 is transferred from the 01 data input of 9309 to the Ql output Flag is high at this time it immediately goes low is reset to a logic I when the output of the Timer goes high aga n g BCD Hold This Hold circuit is activated by a logic 0 at pin 23 of the 37 pin Digital Output con nector J302 The Hold remains in effect as long as the logic 0 is present logic 0 at pin 23 puts a logic 0 at one input of each gate in the Quad 2 Input NAND gate U307 With a logic 0 at one input each NAND gate ou
23. V 0 02 100 0 0152 100 0 2 digits 1 000000 V 1 V 0 0052 1 000 V 2 digits 10 00000 V 10 0 0052 10 00 digits 100 0000 V V 1000 0000 V V 100 V 0 0052 100 0 V 2 digits 1000 V V 0 005 1000 2 digits 36 1174 MODEL 160B MAINTENANCE TABLE 6 5 Accuracy Check for Current Source B Source E Range Source Display Tolerance Setting Setting Range Accuracy Reading on Reading 0 11 10 9 10 nA 0 072 10 00 5 digits 1 01 10 MQ 100 nA 0 025 100 0 3 digits 1 01 1 1 0 025 1 000 3 digits 1 01 100 10 YA 0 025 10 00 uA 3 digits 1 01 10 100 uA 0 025 100 0 uA digits Source D Setting l mA 10 mA 100 mA 1000 mA See Specifications for temperature coefficient for dc current 2 Accuracy Verification 6 4 ADJUSTMENT CALIBRATION PROCEDURE The follow ing adjustments should be performed when any speci a Connect Resistance Source E in series fication has been determined to be out of tolerance with Voltage Source B to form a current source For checking the Model 160B to its maximum published for 10 100 luA lOuA and LOOWA ranges specifications the Performance Verification proce dures given in Section 6 3 should be used For main b Set Voltage Source B to 0 000000V and taining the Model 160B on a six month recalibration Resistance Source E to 00 cycle Tables 6 8 6 9 and 6 10 should be used The Tolerance on Reading given in T
24. banana plugs spade lugs and phone tips All copper leads and terminations are best for measurements on the lmV and 10 ranges 3 4 HOW TO SELECT FUNCTION Function is selected by means of a single front panel Range Switch The Range dial is marked in engineering units for meas urement of voltage mV V current nA mA and resistance 0 kQ 0 For each function rotating the knob clockwise causes the Model 160B to switch to a less sensitive range a DC Voltage The voltage sectors of the Range Switch are designated in millivolts mV and volts V for full ranges from lmV to 1000V A full stop at the 1000 volt range prevents inadvertant switch ing to the nanoampere ranges by clockwise rotation b Resistance The resistance sectors of the Range Switch are designated in ohms 2 kilohms and megohms for full ranges from 1 ohm to 1000 megohms c Current The current sectors of the Range Switch are designated in nanoamperes nA micro amperes uA and milliamperes mA for full ranges from 10 nanoamperes to 1000 milliamperes TABLE 3 1 Summary of Operation in LINE CHG and BAT Modes Condition of Instrument Line connected 1688A installed Switch Line Connected Position 1688A not installed Line not connected 1688A installed 0976 MODEL 1608 OPERATING INSTRUCTIONS RANGE 5101 FIGURE 10 Front Panel Controls 3 5 HOW TO MEASURE VOLTAGE The Model 160B ures
25. be released after the Flag has gone first from high to low and then from low to high Un like the BCD Hold it is very unlikely that ac tivating or releasing the Display Hold during Flag low time would produce mixed data at che display and Digital Output If t does not matter whether the retained data is from the most recent conversion or the conversion imme diately preceeding it the Display Hold can be applied arbitrarily In any operating system however the Display Hold should be synchronized in some way with the Flag 21 OPERATING INSTRUCTIONS BRACKET LEFT MODEL 160B BRACKET RIGHT p eO PHILLIPS SCREW INSERT MODEL 160B THROUGH OPENING FROM BACK OF PANEL m SUPPORT PLATE FRONT PANEL SLOTTED SCREW FIGURE 20 Rack Mounting of Model 160B 3 16 HOW TO RACK MOUNT THE MODEL 160B Model 1010 Rack Mounting Kit adapts the Model 160 for standard 5 1 4 in x 19 in rack mounting with 11 in depth behind the front panel a Using two Phillips Screws Item 7 attach Sup port Plate Item 2 to Front Panel Item 1 b Using four Phillips Screws Item 7 attach left and right side Brackets Items 3 and 4 to Front Panel Item 1 c Using four Phillips Screws Item 7 secure left and right side Brackets to Support Plate Item 2 d Assembly of rack hardware complete except for mounting of In
26. eic R307 C 8 U314 D 7 MODEL 16028 a ota R308 C 6 U315 D 6 0303 5 R309 C 5 U316 D 5 n 0302 R310 D 3 U317 D 4 1318 D 2 930 1319 C 1 U D 1 8 A B C D E F G H FIGURE 43 Component Layout 352 ee A Werav Tec SNOLYNDIS3Q 25 0350 SANOLWNOIS30 JU YW3 5S iS3H5iM TOt 41440 wieOs 530820 uq SOvaY402 4 48 35098439410 O3 vri 55374 s3QYvu YjOW2 Ni Jer SINIYA Tw A gt smOt x 35 310 53 MO SAHO M Juv SIMA BOLSIS3e w zac 42 Fao C T iH 19 i w 0 NN 5054 Q 100 90 vi esocu ss 5 lt 20 0 8 ut TOTT
27. gives additional information on open collector outputs 2 Flag Reset Line Flag may be reset at any time by setting Flag Reset to logic 0 The Flag is reset by the transition of the Flag Reset line from logic 1 to logic 0 signal at the Flag Reset line may be either a pulse or a level When a pulse is used the pulse width should be at least 1 If a level is used a logic 0 on the Flag Reset line will not prevent the Flag from going high when the next good data is available 3 BCD Hold If this line is set to logic 0 the data at the Digital Output will not be updated as conversions are completed Flag will operate normally When BCD Hold is returned to logic 1 the Digital Output will be updated normally New data will be available beginning with the next logic 0 to logic 1 transition of the Flag The BCD Hold is uot synchronized with a particular point in the conversion cycle When the BCD Hold line is set to logic 0 the updating pulses to the Digital Output latches are blocked If the BCD Hold is activated during the time when Flag is normally low either none of or some of the Digital Output latches will be updated If the BCD Hold is released during the time when Flag is normally Low only some of the Digital Output latches may be updated at the next Flag high For these reasons the BCD Hold should be activated and released only during the time when the Flag is normally high this s a
28. is used 2 BCD Digits The 3 least significant digits of the numerical data are represented in BCD 1 2 4 8 form Each digit individually controlled by a strobe line A high output is equivalent to logic 1 3 Overrange Digit Overload and Polarity These three lines are controlled by the same strobe The presence of the overrange digit is indicated by a high output An overload condition is indica ted by a low output For polarity is repre sented by a high output 4 Decimal Point Lines The three lines are controlled by a single strobe The state of these lines is dependent on the setting of the Model 160B Range Switch the data on these lines is not latched DPL is the decimal point to the left of the hundreds digit DP2 is to the left of the tens digit DP3 is to the left of the ones digit 1174 NOTE During an overload the numerical data pre sent at the Digital Output is 1777 This could be mistaken for a valid reading unless the Overload line is used to signal an overload condition e Flag and Flag The Flag line is high for ap proximately 200mS during a normal no Flag Reset conversion cycle The Flag line is low for approx imately lOmS See Timing Diagram for Model 16028 Figure 19 During the time that the Flag is high the data n the Digital Output latches is not changed l Flag Timing The Flag is synchronized with an internal sign
29. power for the 12V supply Bat tery test point A provides a measurement of the 16 8V battery supply with respect to power supply low Therefore the voltage measured is the difference be tween the battery supply and the 12 volt output which is approximately 4 8 volts Battery test point B provides a measurement of the 8 4 battery supply c Battery Charging In the Charge mode the 8 4V batteries are connected between the output of CR203 and the input of 0207 To accommodate the batteries in series with the regulator U207 one AC input of CR203 is switched to a higher voltage tap pin 12 on transformer T201 The 16 8V batteries are connected between CR204 and U208 and CR204 is switched to pin 9 of T201 Actual charging of the 8 4V batteries is accomplished by the current pulses in filter capaci tor C203 charging of the 16 8V batteries is by cur rent pulses in C206 TABLE 4 4 Pin Identification for LSI Function Segment drive Segment drive Multiplex line Multiplex Line Not Used Threshold input 5V or 12V Function Voltage Levels Decimal point 5V ON OV 16 44 17 TO Multiplex line 5v ON OV OFF 18 Fl Not Used 19 FA Not Used 20 Power 45V 45V 21 12V Power 12V 12V Clock Approx lOkHz 2 COM Common or LO OV i
30. powered from line voltage or from rechargeable nickel cadmium bat teries when the optional Model 1688A Rechargeable Battery Pack is installed a How to Operate From Line Power The Model 160B provides a three wire cord which mates with third wire grounded receptacles see Figure 4 for plug configura tion The permanently installed line cord is stored by wrapping the cord around the base of the instru ment as shown in Figure 4 l How to Set Line Switches The Model 160B has two rear panel Line Switches which enable selection of line voltages over ranges from 90 110V 105 125V 195 235V or 210 250V To operate from line power determine the appropriate line voltage range to be used and set the Line Switches as follows TABLE 2 1 Summary of Line Switch Settings 90 110V LOW 117 NORM 117 LOW 234 NORM 234 105 125V 195 235V 210 250V For example if the line voltage to be used is approximately 115 volts select NORM and 117 which permits a range of operation from 105 to 125V After Line Switches are set connect the line cord and set the Power Switch to LINE 2 Line Fuse Requirements The Model 160B uses two line fuses to protect the line operated power supply The fuse types are 1 8 ampere 3AB slow blow Replace with Keithley Part No FU 20 3 to Replace Fuses in Model 1688A The Model 1688A uses l ampere fuses to protect the power supply regulators in case of malfunction Fuses F203 and
31. probe tip plus ground clip to make connections to circuit under test See Section 5 for complete specifications f How to Use Model 1682 RF Probe make rf measurements connect the Model 1682 Probe to the Model 160B input terminals Set the Range to desired voltage range Maximum allowable input is 30V rms ac 200V dc 10 MODEL 1608 3 6 HOW TO MEASURE RESISTANCE The Model 160B measures resistance in 10 ranges 19 100 1000 1 10kQ 100 0 1 0 LOM 100 and 1000 2 a How to Select Range Function and range is selected by rotating the Range Switch to the appro priate position Three positions direct reading in ohms 0 three positions direct reading in kilohms four positions are direct reading in megohms 0 Decimal point is selected by Range Switch If the input signal exceeds twice full range the display blanks to indicate an overrange condi tion TABLE 3 3 Resistance Current Ranges Impressed Current Range Max Setting Display Units 1 Q 1 999 amp 10 19 99 100 199 9 9 1 1 999 10 19 99 100 199 9 1 1 999 MQ 10 19 99 MQ 100 199 9 MQ 1000 1999 MQ b How to Determine Accuracy The accuracy of the Model 160B 18 specified in terms of a percent of reading and a percent of range For example a dis play of 1 000 kilohm k2 will have an uncertainty of 0 004 9 c How to Measure LOW ohms When making meas urements on the 10
32. the HI terminal of the Model 160B for a self check or other voltmeter to test points A or B and observe the measured voltage If a separate voltmeter is used it is necessary to make a con nection to the LO terminal of the Model 1608 since both points A and B are to be referenced to circuit low Table 2 3 gives the battery voltages requir ed at each test point IMPORTANT The instrument must be operated in the BAT mode n order to obtain a val d battery con dition at test points A and B This will ensure that the batteries are supplying power to the instrument If the voltages are measured when the Model 160B is opera ted in the LINE mode a different reading may be observed since the batteries are not connected and therefore do not supply power to the instrument 0976 Test Point TABLE 2 3 Summary of Battery Voltage Levels BAT mode 1 Acceptable Battery Levels Recharge l gera Range Normal if below Tested 2 59 9V 4 8N 2 5V 42 7V 10 5V 8 4V 7V BA 30 3 How to Charge Batteries The Model 1608 pro vides built in recharging circuitry for recharging the Model 1688A Battery Pack recharge the n ternal batteries connect the Model 1608 to line power and select the CHG position Recharging time is dependent on the condition of the batceries at the time of recharge Typically the recharge tinc is 1 1 2 hours per hour of discharge or 9 hours ut charging time for every
33. the analog output is at the same potential as the LO input term nal of the Model 160B 3 14 HOW TO USE MODEL 160B OFF GROUND The LO terminal can be operated off ground at potent als of up to 1200V Isolation from the LO terminal to power line ground is specified at 1000 02 1090 shunted by 300pF Typically the isolation resis tance from LO to GND is two decades greater than 1092 10 10 Because of this excellent isolation operating the Model 160B off ground results in very little Loading from LO to GND of a floating source At 1000V above ground the Model 160B will require typically only from the source The excellent isolation also accounts for the high common mode re 14 MODEL 160B MODEL 1608 DIGITAL MULTIMETER i TYPICAL 10110 ISOLATION RESISTANCE Floating Operation jection ratio of the Model 1608 Even with the HI terminal driven and a source resistance of 1k2 1000 VDC from HI to GND will produce typically only lOuV DC error This error voltage is determined dir ectly from the ratio of the source resistance to the isolation resistance See Figure l4 Vacrose lk 7 1 x 189 107 x 10 10uvDC The isolation capacitance from LO to GND is impor tant when AC common mode s gnals are present In the Model 160B this capacitance is specified at 300 pF maximum At a frequency of 60 Hz 300 picofarads has a reactance of approximately 10 0 With the HI term
34. 0 876 10 5 R303 Thick Film Network s saas v 4 p sow x KI EU ES TF 39 4 R304 Thick Film Network Kl 45 0 TF 39 R305 Thick Film Network es lt a s KI Kares TF 39 R306 Thick Film Network lt lt s 0 0 s s 4 on KI Ve voa TF 39 R307 10 9 250 Comp A B CB 103 104 amp 76 10K R308 10 0 10 0 25W Comp e ee lt w n 103 10 R76 10K ae R309 lOkQ 102 0 25W Comp s 0 0 on on n A B CB 103 10 R76 10K 8310 10 0 10 0 25W Comp 103 10 R76 10K INTEGRATED CIRCUITS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty U301 Hex Inverter l6 pin RCA CD4049AE 106 1 0302 Quad 2 input NOR l pin DIP s e eza ze 0 RCA CD4001AE 1C 108 U303 Quad 2 input NOR l pin RCA CD4001AE IC 108 34 1304 Quad 2 input NOR l pin RCA CD4001AE Ic 108 i U305 Dual 4 Input NOR 14 RCA CD4002AE IC 105 di U306 Timing Circuit 8 pin SIG NE555V IC 71 1 U307 Quad 2 input NAND l pin RCA CD401LAE 102 3 1308 Dual D Type Flip Flop 14 RCA CD4013AE 103 2 0309 Dual Type Flip Flop 14 pin DIP RCA CD4013AE 103 9310 Quad Clocked Latch 16 RCA CD4042AE
35. 01 Transistor NPN Case TO 106 FAIR 2N3565 16 39 D102 Transistor NPN Case TO 106 FAIR 2N3565 TG 39 D103 Diode MOT 1N4006 RF 38 R101 Resistor 3 92 0 1 1 4W CbF DALE DC 1 4 3 92M R178 3 92M R102 Resistor Selected in Test IRC CEA TO R88 R103 Resistor l MO 0 1 1 8W MtF DALE MFF 1 8 1M RL79 1M R104 Resistor 100 10 1 4W Comp OHM 101 102 R76 100 32 1174 MODEL 160B ACCESSORIES Model 1688A Rechargeable Battery Pack Description The Model 1688A is a field installable rechargeable battery pack for use with the Model 160B The Model 16884 includes seven nickel cadmium C cells and one 16 8V nickel cadmium pack Specifications Operate Time Continuous operation of Model 160B from full charge is 6 hours minimum Recharge Time 1 1 2 hours per hour of discharge fully charged within 12 hours Added Weight 2 pounds 1 kg Added Power When Charging 4 watts Fused for l ampere Storage Temperature 25 to 45 C 155B8A BATTERY KEITHLEY e Model 1683 Universal Test Lead Kit Description The Model 1683 is a set of flexible test leads 40 in 1 m in length with interchangeable screw on adapters s a Contents Qty Description 2 Test Leads 40 in 1m 1 red 1 black 4 Alligator clip adapter 4 Banana plug adapter mem 2 Probe 1 red 1 black 2 Spade lug adapter e 2 Phone tip adapter 25 Model 1600 High Voltage Probe T
36. 08 Housing Female 5 pin s s lt lt k s 0 v x BERG 20370 CS 251 J109 Housing Female 5 pin BERG 20370 CS 251 1110 Housing Female 3 pin sr ol BERG 65039 034 5 270 J111 Housing Female 5 pin lt s o gt BERG 20370 CS 251 J112 Binding Post Black 7 BERG BJ 65 1 J113 Binding Post Red BERG BJ 6R i J114 Housing Female 3 BERG 65039 034 CS 270 4115 Binding Post 255374 1 116 Binding Post Black KI 25539 1 4206 Housing Female 10 pin BERG 20052 CS 237 1207 Housing Female 10 pin 4 4 on n BERG 20052 CS 237 n J208 Housing Female 2 pin lt 4 wee BERG 65039 035 CS 266 4 101 Male 3 seses CS 339 3 2 P102 Male Pin 2044 Be Se ek ay KI sie das 24249A 2 P103 Male Pin OEC UM eR Wis KI 24249 104 Male Pin 63 KI Sisters 24249A a 105 Male l pins 2225 25 04 w a CS 339 10 1 P106 Male 4 ping 5 0 9 Go ee 0 eee C8 339 4 2 P107 Male 5 plHu8 cel Der Er a KT P C 339 5 2 P108 Male 5 4 109 Eo wU ye W KI iat ay 5 339 5 P109 Male Bin 3 w 4 ox Qoo
37. 1 100 004 201 250 100 199 9 MI 10 0 01 100 03 90 256 1000 1999 0 30 0 01 100 10 001 250 0 6 volt maximum into an open circuit GENERAL DISPLAY 3 digits plus 1 overrange digit decimal position ENVIRONMENT polarity and overioad indication 5 readings per second 3 least significant digits blank when overload condition exists except on 1000 volt range ISOLATION Lo to power line ground greater than 1000 megohms shunted by less than 300 picofarads Lo may be floated up to 1200 volts with respect to power line ground ANALOG OUTPUT 1 volt dc at up to 1 milliampere for fuil range input 100 overranging except on the 1000 voit range where overranging is 20 OFFSET CURRENT Less than 10 picoamperes WARMUP 1 2 hour to complete stabilization Operating 10 C to 35 C 0 to 80 relative humidity 0 to 10 C and 35 C to 50 C 0 to 80 relative humidity within twice computed accuracy Storage 25 C to 70 C without batteries installed 25 C to 45 C with batteries installed POWER 90 110 105 125 195 235 or 210 250 volts switch selected 50 60 Hz 5 watts Optional rechargeable 6 hour battery pack CONNECTORS Input binding posts Analog Output banana jacks DIMENSIONS WEIGHT Style K 3 1 2 in high x 9 1 4 in wide x 10 3 4 in deep 85 x 235 x 275 mm Net weight exclusive of batteries 4 pounds 1 8 kg GENERAL INFORMATION MODEL 1608 N
38. 107 farad piv peak iuverse voltage P plug poly polystyrene pot potentiometer variable resistor p p peak to peak ppm parts per million 9 transistor QA integrated circuit all types R resistor ref reference RN resistor network rma root mean square 5 switch SPDT single pole double throw SPST single pole single throw T transformer Tan cantalum TC temperature coefficient tol tolerance trim trimmer y volt or vacuum tube all types vac volts alternating current vdc volts direct current W watt ww wirewound 1174 45 REPLACEABLE PARTS BERG BOURN BUSS CENLB CLARO CTS DALE DICK EDI ERIE Cross Reference of Manufacturers NAME AND ADDRESS Allen Bradley Corp Milwaukee 53204 Amperex Elkgrove Village IL 60007 Amp Inc Elizabethtown PA 17022 Analog Devices Inc Cambridge MA 02142 Beckman Instruments Inc Fullerton CA 92634 Berg Electronics Inc New Cumberland PA 17070 Bourns Inc Riverside 92507 Bussmann Mfg Div St Louis MO Centralab Division Milwaukee WI 53201 Clarostat Mfg Co Inc Dover NH 03820 Components Inc Biddeford ME 04005 Continental Wirt Electronics Corp Philadelphia PA CTS Corporation Elkart IN 46514 Dale Electronics Inc Columbus NB 68601 Dickson Electronics Corp Scottsdale AZ 85052 Electrocube
39. 1C103 2 C247 0 01M l C202 0 01 uF 500V ERIE 871 25U0 103M 22 0 01 C203 2000 pF 25V 2 RICH JC P 2000 25 8P C255 2000M i C204 39 yF 15V COMPI TD4 015 396 10 C228 39M C205 Not Used 4 6 vade I C206 470 50V EAL ve s ag ox de UC TEMPL 411 470 F C246 470M 1 C207 20 pF 20V ETT 4 amp 94 WL COMP 1 TD2 20 106 20 C179 10M DIODES CR101 Rectifier l 800 MOT 1N4006 RF 38 3 CRIO2 Computer Type 75mA 75 TEXAS 14914 RF 28 3 CR103 Rectifier 800 MOT 1N4006 RF 38 CR104 Rectifier lA 800V 9 x94 wo N MOT 1N4006 RF 38 CR105 Rectifier 150 125 FAIR 1N3595 RF 43 1 CR106 Computer Type 75mA 75V t on e on on TEXAS 1 914 RF 28 CR107 Not Used lt 4 6 0 4 9 c wow o m EL 244 202 Les eas TREES CR108 Bridge Rectifier 4 diode 50V 0 we EDI PEOS RF 48 1 CR201 Computer Type 75mA 75V TEXAS lN914 RF 28 zy CR202 Computer Type 75mA 75 TEXAS lN914 RF 28 ak CR203 Rectifier Bridge 1 5A 400 EDI 40 RF 46 2 CR204 Rectifier Bridge Type 1 5 400 EDI 40 RF 46 DISPLAYS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty DS201 Digital Displ
40. 6 2 105 H 5 R121 D 1 R209 J 7 C105 G 1 P106 4 5 R122 D 1 R210 J 7 C106 H 2 P107 G 2 R123 E 1 R211 1 6 107 F 1 P108 G 4 R124 F 3 R212 B 6 C108 E 1 P109 G 4 R125 F 3 R213 6 109 1 P110 3 R126 E 3 R214 C 8 C110 2 111 F 3 R127 E 2 R215 8 C111 F 2 P114 B 4 R128 E 3 R216 C 6 C112 F 3 R129 E 3 R217 E 7 C113 E 3 P203 8 R130 2 R218 F 6 C114 E 4 P205 A 8 8131 p 2 C115 C 3 P206 G 8 R132 C 6 S101 J 3 C116 C 4 P207 G 8 R133 6 C117 C 4 P208 c 4 R134 D 4 5201 5 C118 C 4 R135 D 2 202 A 6 119 4 0101 E 4 R136 E 4 5203 H 8 C120 E 5 0102 2 R137 D 4 Q103 E 2 R138 E 6 T201 B 4 C201 B 6 Q104 D 2 R139 H 4 C202 C 7 Q105 F 6 R140 H 5 TP101 F 6 C203 B 4 Q106 E 5 R141 J 5 C204 B 2 R142 H 5 TP201 3 C206 1 0201 6 R143 H 5 TP202 B 6 C207 3 0202 G 6 R144 5 0203 G 6 R145 J 4 0101 E 5 CR101 5 0204 5 6 8146 1 4 1102 4 CR102 F 5 Q205 G 6 R147 G 4 U103 D 2 CR103 6 2 0206 C 6 R148 G 4 U104 E 3 CR104 F 2 Q207 7 R149 F 4 U105 E 4 CR105 E 3 R150 G 5 U106 D 3 CR106 3 2101 4 RISI G 5 1107 D 3 CR108 J 6 R102 E 5 R152 G 5 U108 D 5 R103 5 R153 G 5 0109 D 5 CR201 D 7 R104 D 5 R154 F 5 U110 5 CR202 C 7 R105 D 5 R155 C 5 CR203 3 R106 E 5 R157 D 6 U201 D 7 CR204 2 R107 D 5 R158 C 5 U202 C 7 R108 F 3 R159 J 2 U203 E 6 F101 J 5 8109 F 4 R160 2 1204 D 7 R110 F 4 8161 D 3 U205 G 7 F201 7 R111 3 R162 D 3 U206 F 7 F202 A 7 R112 E 5 8163 H 6 U207 8 5 R113 E 5 1208 2 1201 D 8 R114 J L R201 D 7
41. 6 hours of operating time in the battery mode CAUTION Overcharging the batteries will raise the internal temperature of the instrument and may also shorten the life of the batteries NOTE The Model 1608 may be operated while in the CHG mode However if the Battery is not installed the Model 1608 will not be operable when the CHG mode is selected since the batteries are connected in series with the line power supply OPERATING INSTRUCTIONS SECTION 3 3 1 GENERAL This section provides information needed to operate the Model 160B for measurement of voltage current and resistance 3 2 HOW TO SELECT POWER The Model 160B may be powered from line voltage or rechargeable nickel cad mium batteries when the Model 1688A is installed The Model 160B has a built in line voltage power sup ply and line cord If the accessory Model 1604 Re chargeable Battery Set is ordered and installed then the user has the option of selecting line or battery operation via the front panel rotary power switch NOTE The accessory Model 1688A Rechargeable Bat tery Set may be ordered at the time of pur chase of the Model 160B or may be purchased and field installed at a later time 1f so desired The Model 1688A features plug in wiring As a result no modifications need to be made to the Model 160B chassis a How to Operate from Line Power The Model 1608 can be powered from Line voltage over four ranges from a minimum of 90
42. 608 is internally fused beyond three amperes input pro tection circuit limits the voltage applied to the shunt resistor to approximately 1 5 volts thereby reducing the possibility of over heating the resistor 1 How to Check Current Fuse Select l000m range Verify input resistance of less than ohm If greater than 1 ohm replace fuse Keithley FU 43 2 How to Replace Current Fuse The current fuse 101 is located on the printed circuit board PC 349 and is installed in a socket The fuse is accessible by removing the top cover See Figure ll An accessory fuse is furnished with each instrument Fuse rating is 3 amperes OPERATING INSTRUCTIONS d How to Use the Model 1651 Current Shunt for measurements to 50 Current measurement capability of the Model 160 may be extended to 50 amperes through the use of accessory Model 1651 50 Ampere Shunt Model 1651 permits 4 terminal connections to minimize measurement error due to lead resistance To use the Model 1651 connect the voltage sensing leads to the Model 160B input terminals Connect separate current leads not furn shed between the source and the large hex head bolts on the Model 1651 The current leads should be rated for currents up to 50 amperes The shunt resistance is 0 001 ohm which produces a sensitivity of lmV Amp As examples 10 amps current results in a 10 drop on 10mV RANGE and 30 amps yields a voltage drop of 30mV which can be read on t
43. AL COUNT NOW SIGNAL 201mS DIGITAL OUTPUT DIGITAL OUTPUT LATCHES UPDATED LATCHES UPDATED EXPLANATION OF EVENTS 1 Conversion cycle 1 complete Latches in LSI circuit in Model 1608 updated 2 Digital Output latches updated with data from conversion 1 Flag Tine goes from 0 to 1 3 BCD Hold goes low after Flag line has gone high 4 Flag line goes high Digital Output latches still contain data from conver sion 2 because BCD Hold line is low BCD Hold released after Flag line has gone high Flag line goes high Digital Output latches now contain data from conversion 4 Flag Reset goes from 1 to 0 causing the Flag to go from 1 to 0 Flag line goes high even though Flag Reset line is still low Digital Out put latches contain data from conversion 5 FIGURE 19 Timing Diagram for Model 1602B 20 1174 MODEL 1608 f Output Control Lines The Model 1602B has six Strobe lines a Flag Reset line a BCD Hold and a Display Hold 1 Strobe Lines All data outputs are grouped into 3 and 4 line groups Each group is controlled by a Strobe line Flag and Flag are also control led by a Strobe line Logic 1 on a Strobe line turns all the transistor open collector outputs off in a particular group A logic 0 on a Strobe line enables the data to determine the logic states of the group The groupings are indicated in Table 3 8 Section d above
44. I ANALOG OHMS AMPLIFIER REFERENCE INPUT LO FIGURE 23 Resistance Operation INPUT HI ANALOG AMPLIFIER RANGE SWITCHING INPUT LO OVERLOAD PROTECTION FIGURE 24 Current Operation 1174 THEORY OF OPERATION b Ammeter Circuitry Currents are measured with the Model 160B by shunting resistors across the input of the analog amplifier resistors used for the current ranges are R139 through R146 and R163 Table 4 2 shows the value of the shunt resistor and the analog amplifier full range sensitivity for each current range of the Model 160B On the high cur rent ranges 100yA through 1000mA where the value of the shunt resistor is low the analog amplifier senses the voltage drop right at the resistor On the low current ranges 10 through 10yA the analog amplifier senses the voltage drop at the Model 1608 terminal To approximately determine the total input resistance of the Model 1608 on the high est current ranges add 0 10 internal wiring resis tance to the value l sted for the shunt resistor Table 4 2 Diode network 108 and fuse 101 pro vide over current protection on the through 1000mA ranges The diode network will not allow the input voltage to exceed approximately 1 5 volts for currents up to 3A thus protecting the shunt resistors For currents above the fuse will open On the 10 and 100nA ranges the shunt resistors by themselves can wi
45. IELDING HOW TO USE THE ANALOG OUTPUT pue os HOW TO USE MODEL 1608 OFF GROUND HOW TO USE MODEL 1602B DIGITAL OUTPUT HOW TO RACK MOUNT THE MODEL 1608 THEORY OF OPERATION 4 1 4 2 4 3 8 4 5 GENERAL ANALOG AMPLIFIER CIRCUITRY woo 3 ANALOG TO DIGITAL CONVERTER POWER SUPPLY ko de ee MODEL 1602B DIGITAL OUTPUT ACCESSORIES 4 4 MODEL 1601 DC PROBE m MODEL 1688A RECHARGEABLE BATTERY PACK MODEL 1683 UNIVERSAL TEST LEAD KIT MODEL 1600 HIGH VOLTAGE PROBE MODEL 1682 RF PROBE MODEL 1609 CALIBRATION COVER zog MODEL dad CLIP ON TEST SET MAINTENANCE 6 1 6 2 6 3 6 4 REPLACEABLE PARTS 2 7 1 7 2 73 GENERAL 4 c REQUIRED TEST EQUIPMENT mot m non PERFORMANCE VERIFICATION ADJUSTMENT CALI BRATION PROCEDURE GENERAL i ORDERING INFORMATION SCHEMATICS D MODEL 1603 0976 MODEL 160B 0976 ILLUSTRATIONS Dimensional Data ot rn re re ew eee Tilt Bail Positions Front Panel Bottom View Showing Line Cord Rear View Showing Line Switches Model 1688A Rechargeable Battery Pack Exploded View of Model 160B 1688A Installation of Battery Pack Battery Test Location Fro
46. Inc San Gabriel CA 91776 Electronic Devices Inc Yonkers NY 10710 Erie Technological Products Inc Erie PA 16512 TABLE 7 2 FAIR GE GENI H P INTER IRC CAN KI LITFU MOLEX MOT NAT RCA RCL SIG SIEM TEMPL TEXAS VISH MODEL 160 NAME AND ADDRESS Farichild Instruments Corp Mountain View CA 94040 General Electric Company Syracuse NY 13201 General Instrument Corp Newark NJ 07104 Hewlett Packard Palo Alto CA 94304 Intersil Cupertino CA 95014 IRC Division Burlington IA 52601 ITT Cannon Electric Santa Ana CA 92701 Keithley Instruments Inc Cleveland OH 44139 Littlefuse Inc Des Plaines IL 60016 Molex Douners Grove IL 60515 Motorola Semiconductor Products Inc Phoenix AZ 85008 National Semiconductor Corp Santa Clara CA 95051 RCA Corporation Comerville NJ 08876 RCL Electronics Inc Manchester NH 03102 Signetics Corp Sunnyvale CA 94086 Siemens Corporation Iselin NJ 08830 Temple Tecate CA 92080 Texas Instruments Inc Dallas TX 75231 Vishay Resistor Products Malvern PA 19355 46 1174 MODEL 160B REPLACEABLE PARTS CAPACITORS Circuit Mfr Keithley Desig Description Code Desig Part No Qty C101 2200 pF 500 ERIE 831250U0222M 22 2200 C102 100 pF 1000V CerD ww n n CEN
47. Instruction Manual Model 160B Digital Multimeter Contains Operating and Servicing Information for Model 160B Digital Multimeter and Model 1602B Digital Output 1975 Fourth Printing December 1977 Keithley Instruments Inc Instrument Division Cleveland Ohio U S A INSTRUCTION MANUAL MODEL 1608 DIGITAL MULTIMETER AND MODEL 16028 DIGITAL OUTPUT Q COPYRIGHT 1975 KEITHLEY INSTRUMENTS INC FOURTH PRINTING DECEMBER 1977 CLEVELAND OHIO U S A CONTENTS SECTION SPECIFICATIONS Eod od CONTENTS GENERAL INFORMATION RT I I I 1 Qy APU 5 P ONIN EH Mw VA UO w w w VJ w w w w w w w N N w 3518 3 16 INTRODUCTION FEATURES 4 WARRANTY INFORMATION CHANGE NOTICE OPTIONAL MODEL 1602B DIGITAL OUTPUT OPTIONAL MODEL 16884 RECHARGEABLE BATTERY PACK TIAL PREPARATION GENERAL INSPECTION p PREPARATION FOR USE ATING INSTRUCTIONS GENERAL HOW TO SELECT POWER fe oie RECS HOW TO MAKE INPUT CONNECTIONS HOW TO SELECT FUNCTION HOW TO MEASURE VOLTAGE HOW TO MEASURE RESISTANCE AE HOW TO MEASURE CURRENT e gt NOISE CONSIDERATIONS 6 es THERMAL EMPS eee s MAGNETIC FIELDS n AC ELECTRIC FIELDS P SH
48. J202 H 7 R115 F 3 R202 C 5 R116 H 2 R203 7 P101 G 2 R117 G 2 R204 7 VRLOL c 5 VR102 C 3 62 0875 NOTES P204 tr 2 132444 r 279 3 DISPLAY BOARO 2 ALL FESISTOA VALUES ARE IN 5 UNLESS MARKED OTHERWISE K KILGHMIS M MEGCHMS ALL CAPACITOR VALUES IN lt UNLESS MARKED OTHERWISE pr BICC FAHD i CONNECTS DENOTES FRONT CONTROL TC P3Ci DWG DENOTES PEAR CONTROL pon PSE Dwa 63 DENOTES INTERNAL aDJ za DENOTES CLOCKWISE RGTATION DENOTES LINE CORD GAEEN LEAD 4 DENOTES PUNEA SUPPLY 720 D gt FLAG NOTES WITH SAME NUVEERS APE CONNECTED ROTARY SWITCHES SHOWS i Clow PUSITION Le z WHEN THE H P DIGIT P 5082 7732 iS USED FOR lt ie 05201 PINS 4 AND ARE INTERNAL CONNECTED AND MUST SE CLIPPED GFF FOH HE SIGIT 70 t FUNCTION PROPERLY 7 SEE ORW T 26590 R203 TP2c2 5 DECK A 5203 DECK ee sas eee 32267 4 0207 i k 5 gt _ lt N sv i F Z C204 7 5 1 4 9207
49. L MODEL 16028 DIGITAL OUTPUT Model 16028 is a field installable digital output option which enables digital data recording and processing The open collector BCD outputs are TTL compatible 1 6 OPTIONAL MODEL 1688A RECHARGEABLE BATTERY PACK The Model1688A is an accessory battery pack which en ables either line or battery operation by use of the front panel Power Selector Switch The Model 1608 provides built in recharging circuitry for use with the Model 1688A The battery pack is field install able in the Model 160 chassis MUL TIMETER Front Panel INITIAL PREPARATION MODEL 160B HANDLE AND TILT BAIL j CONDENSED TING HNST UC UNS TO OPEN iNSTHUMENT i5 pee ELAN sa n et MAS C SAM Od s GAEL AS ac vau 15 CURRENT naus LINE STORAGE AGL DOR RANGES N x eam VERTA ways LINDICAIQN Be IN D ORIS es rower U WAN Vrae s yya t 5 ort gt 5 LINE E i dE 5 5 BAT TEST 8 CONDENSED OPERATING INSTRUCTIONS S SCREW LOOSEN FOR DISASSEMBLY FIGURE 4 Bottom View Showing Line Cord 2 1174 MODEL 160B INITIAL PREPARATION 112 4113 5201 S202 DIGITAL ANALOG OUTPUT QUTPUT J302 LINE VOLTAGE SWITCH SETTINGS 90 10 LOW 17
50. LB DD 101 C64 100P 1 C103 0 1 uF 250 AMPRX 280 100 C128 0 1M 3 C104 0 56 SOV ECI 625B1A474 C201 0 56M 1 C105 0 01 pF 250V AMPRX C280AE P10K 178 01 1 C106 0 0022 200V MPCb se 0 e na on n on n ECI 625 1 221 0022 2 C107 0 1 uE 250V AMPRX C280AE P100K C178 0 1M C108 100 pF 630V SIEM B31360A1101H C252 100P 2 C109 100 pF 630V SIEM B31360A1101H C252 100P C110 0 0022u0F 200 MPCb w e soens ee on on 0 on on ECI 62581C222 221 0022 C111 2 50V t P s ECI 625B1A205 215 2 1 112 10 pF 10000 CerD CENLB 00 100 C64 10P 1 C113 10 uF 20V COMPI TSD220106 C179 10M 3 C114 10 iE 20V 3920 0 d SA Ae 07 ya COMPI TSD220106 C179 10M C115 39 pF 15V COMPI TD4 015 396 10 228 39 4 C116 39 uF 15V COMPI TD4 015 396 10 228 394 C117 22 uP 20V COMPT 01 20 226 20 C179 22M gt C118 22 uF 20V COMPI TD1 20 226 20 C179 22M C119 39 uP 15 2 COMPL TD4 015 396 10 228 39 C120 0 1 250V 4 AMPRX 280 100 C178 0 1M C201 0 01 uF 200V ECI 210B
51. ORMAL BENCH POSITION LEVEL POSITION TILTBAIL AT FRONT oe ay lt HANGING POSITION 4 lt 74 SHELF POSITION ndi 45 POSITION LEVEL POSITION TILTBAIL AT REAR FIGURE 2 Tilt Bail Positions vi 1174 MODEL 1608 SECTION 1 l 1 INTRODUCTION The Model 160B is a wide range digital multimeter capable of measuring voltage cur rent and res stance The Model 160B offers seven ranges of voltage from lmV to 1000 volts nine ranges of current from LOnA to 1000mA and ten ranges of re sistance from 12 to 1000 0 Model 160B display is 3 digits plus 100 overrange 1 2 FEATURES a Voltage sensitivity to 1 microvolt per digit b Current sensitivity to 0 01nA per digit c Resistance sensitivity to 0 0010 per digit d Floating capability to 1200 volts above case e Built in analog output f Optional Model 1602B Digital Output g Optional Model 1688A Rechargeable Battery Pack 1808 DIGITAL FIGURE 3 0976 GENERAL INFORMATION GENERAL INFORMATION 1 3 WARRANTY INFORMATION The warranty is stated on the inside front cover of the manual Tf there is a need for service contact your Keithley repre sentative or authorized repair facility as given in our catalog 1 4 CHANGE NOTICE Improvements or changes to the instrument not incorporated into the manual will be explained on a yellow change notice sheet attached to the inside b ck cover of the manual 1 5 OPTIONA
52. Power lt s lt lt lt ua hos KI Qui KN 37 1 EX Knob ZERO X we we n C OU e KI resse KN 36 l MISCELLANEOUS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty 7201 Transformer Power Type m xw TR 156 1 101 Test Point 5 TEA AUS KI 242494 3 TP201 Test Point amp 4 409 oos eo m KI kiq 24249 TP202 Test Point lt s ee e 4 KL 242494 50 0875 MODEL 160 INTEGRATED CIRCUITS Circuit Mfr Mfr REPLACEABLE PARTS Keithley Desig Description Code Desig Part No _ Qty 0101 Operational Amplifier 8 pin NAT LM308N 26426A 1 5102 Operational Amplifier 8 pin DIP lt NAT LM308N 16 99 2 0103 COS MOS 14 DIP 4 a lt 4 4 w s Q a a RCA CD4007AE IC 100 M 0104 Operational Amplifier 8 pin DIP gt NAT LM308N 99 0105 Operational Amplifier 8 70 99 Case A D AD741K 97 l U106 Operational Amplifier 8 pin DIP FAIR Special IC 77 3 U107 Operational Amplifier 8 pin DIP b FAIR Special IC 77 zu U108 Transistor Array l pin DIP e v RCA CA3086 1C 53 j 1109 Operational Amplifier 8 pin DIP FAIR Special IC 77 0110 Operational Amplifier 8 pin DIP gt NAT LM301AN IC 24 U201 Large Scale IC
53. Segment drive 5V ON OV OFF 23 CN Segment drive 5V ON OV OFF 24 T2 Multiplex line 5V ON OFF Segment drive 5V ON OV OFF 25 R4 Not Used Segment drive 5V ON OV OFF 26 RL Not Used Segment drive 5V ON OV OFF 27 R2 Not Used Current Switch 45V integrate mode 28 F2 Not Used 1 A 30 0976 MODEL 160 4 5 MODEL 16028 DIGITAL OUTPUT The Digital Output includes a seven segment to BCD converter latches for demultiplexing output data buffers a t mer to set up the Flag Flag Reset circuitry and other sup porting circuitry It s made up primarily of CMOS logic circuits Seven Segment to BCD Converter This converter uses one Hex Inverter U301 three Quad 2 Input NOR gates U302 U303 and U304 and one Dual 4 Input NOR gate 0305 converter logic takes the multi plexed seven segment data directly from the LSI cir cu t n the Model 160B The output of the converter is a multiplexed BCD code This code is supplied to the inputs of D type latches for demultiplexing When all inputs to the seven segment converter are low as occurs when the Model 160B is in an overload condition the converter output is a BCD 7 b Latches To demultiplex the BCD data for the ones tens and hundreds digits three Quad Clocked D latches are used U310 U311 and U312 U310 is enabled during multiplex interval T3 U311 during
54. V to a maximum of 250V See Tabie 2 1 l Set rear panel Line Switches to appropriate positions as shown in Figure 5 2 Plug line cord into source of line power 3 Set front panel Power Switch to LINE b How to Operate from Battery Power 1 Install Model 1688A Rechargeable Battery Pack 2 Check battery voltages at Test Points A and B to ensure that batteries are charged sufficiently 3 If necessary plug line cord into ac power and set Power Switch to CHG to bring battery volt age up to useable levels 4 When battery level is sufficient disconnect line cord and set Power Switch to BAT MODEL 160B OPERATING INSTRUCTIONS 3 3 HOW TO MAKE INPUT CONNECTIONS The Model 160B has two front panel terminals identified as HI red and LO black These terminals accomodate banana plugs alligator clips spade lugs bare wires and other similar input connections Leads may be fabricated using a good quality copper wire terminated by single banana plugs such as Keithley Part No BG 5 or dual banana plug such as Keithley Part No BG 7 Ready made test leads are also avail abie from Keithley Accessory Model 1681 Clip on Test Lead Set includes two 40 inch long leads ter minated by a banana plug and spring loaded clip which easily attaches to wires and terminals on pc boards etc Model 1683 Universai Test Lead Kit features in terchangeable probe tips for various applications The Kit includes regular probes alligator clips
55. a two stage invert ing amplifier The gain of this inverting amplifier is accurately set to 1 by internal adjustment R134 DC CAL and resistors 1624 B and H R135 ZERO sets the zero offset voltage of U106 equal to 1 2 the zero offset voltage of U107 Thus the zero offset is the same for both positive and negative dc signals and this zero offset can be compensated for with the DISPLAY ZERO R136 Capacitors C115 C116 117 and C118 provide filtering of AC components sent in the input signal b _ Polarity Detector The polarity detection cir cuit uses two transistors 0108 0108 of transistor array These transistors are used as a simple differential voltage amplifier with one output connected to power supply common A positive going output of 106 causes the collector of transistor U108D to go negative When this happens 0206 15 shut off and the segments of display 05201 are also shut off A negative going output of U206 causes base of transistor 0108 to be clamped at approx imately 0 7V which shuts off the collector current of U108D As a result the voltage at the collector of U108D goes to a level of approximately 0 7V which is sufficient to drive Q206 into saturation and turn on the segments of DS201 0976 Absolute TO POLARITY INDICATOR LOGIC TO A D CONVERTER Value Detector Integrator Threshold Detector and 1 51 Circuit These circ
56. ables 6 8 6 9 and c Connect Current Source to Model 160B 6 10 is adjusted to allow for time drift of critical input components and also the effects of humidity Tables 6 8 6 9 and 6 10 also give the probable component d Select imV range on the Model 160B to be investigated if a range does not meet specifi cations after the Adjustment Procedure has been com Adjust zero on the Model 1608 for a 000mV pleted display IMPORTANT The Model 160B factory calibration is at a f Select 10 range on the Model 160 level that will assure all specifications are met for a period of 12 months after shipment g Verify the 10 100 lA lOuA and from the factory For subsequent recalibra 100 ranges using the source settings given in tion a six month re cal cycle 18 recommended Table 6 5 since component tolerance drift may prevent re calibration to stringent factory calibrar on NOTE levels without component replacement The fol lowing calibration procedure uses levels that Voltage Source B must be set lO0mV high to will assure that the instrument meets published compensate for the Model 160B input drop specifications for a six month period without at full range requiring component changes Adjustments should be performed under laboratory condi h Connect Current Source D in place of tions of approximately 25 C and less than 50 previous current source relative humidity i Verify that the lmA 10 100mA an
57. ad decimal position and polarity FLAG FLAG Present for approximately 200 millisec onds during each conversion No change in Digital Output is made during this interval OUTPUT LOGIC LEVELS Output logic I open collector to output LO Output logic 0 closure to output LO Output Device 2N5089 or equivalent greater than 25 volt breakdown less than 0 5 volt while sink ing 15 milliamperes REMOTE CONTROLS Strobe 6 lines for serializing in multiples of 4 bits Logic 1 inhibits controlled output lines Output Hold Logic 0 retains data from last read ing at Digital Output Display Hold Logic 0 retains data from last reading escept for polarity and decimal at Digital Output and Display FLAG FLAG Reset logic 0 resets FLAG and FLAG for remainder of conversion in process CONTROL LOGIC LEVELS Transition from logic 1 to Logic 1 either an open circuit or a voltage be tween 3 5 and 15 volts referenced to output LO Logic 0 closure to output LO within 0 8 volt while sinking 1 milliampere PRINT RATE 5 readings per second ENVIRONMENT Operating 090 to 50 C OZ 80 relative humi dity Storage 25 to 70 C CONNECTOR Output AMP205209 1 DIMENSIONS WEIGHT Mounts inside 160B Field in stallable with screwdriver Adds 0 5 pounds 0 3 kg to 1608 POWER Obtained from 160B Consumes negligible power ACCESSORIES SUPPLIED Output mating connector and hood
58. al from the Model 160B A to D con verter This internal signal designated CN for COUNT NOW is high for 2016 clock pulses and low for 32 clock pulses When makes the transition from high to low the Flag also changes from high to low While is low the latches in the Model 160B LSI circuit are updated and the counters in the LST circuit are reset 2 Digital Output Latch Updating remains low for 3 3mS nominally At the end of this time the data from the most recent conversion is present in the output latches of the LSI circuit This data is presented to both the Model 160B display and the Digital Output is multiplexed form At the Digital Output the data must be demultiplexed This is ac complished by having the 4 multiplex timing signals from the LSI circuit enable the Digital Output latches in sequence Each multiplex signal is high for 825 5 nominally 8 clock pulses This means that the Flag Line must remain low for at least 4 x 825uSec or another 3 3mSec after goes high The Flag line is arbitrarily set up to go low for 10mSec nominally to make sure that the latches in the LSI circuit and the latches the Digital Out put are updated NOTE The DP decimal point data is not latched at the Digital Output However no change in this data will occur during a conversion unless the Range Switch setting is changed OPERATING INSTRUCTIONS MODEL 160B EVENT CN VEN INTERN
59. ay Polarity Overflow s s H P 5082 7732 DD 11 1 05202 Digital Display Seven Segment s eee H P 5082 7730 DD 9 3 D 203 Digital Display Seven Segment a H P 5082 7730 Db 9 05204 Digital Display Seven Segment s sso H P 5082 7730 Db 9 Selected for light intensity D or E 1277 REPLACEABLE PARTS MODEL 1608 FUSES Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty 101 Fuse Microfuse 6 LITFU 273003 FU 43 1 F202 Fuse 1 8 250V 5 1 BUSS MDL 1 8A FU 20 2 F202 Fuse 1 8A 250V 510 10 BUSS MDL 1 8A FU 20 ox F203 Fuse TA 250V 2 0 MED PE BUSS MDL 1A FU 10 2 F204 Pise VAS 7250M4 55205 4 gh S Uu cat Bt BUSS MDL 1A FU 10 CONNECTORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty 2101 Housing Female 3 BERG 65039 034 CS 270 3 1102 Housing Female 2 BERG 65039 035 CS 266 2 J103 Housing Female 1 BERG 47439 CS 236 1 3104 Housing Female 5 pin dd O6 Cute Le Yer ZQ BERG 20370 CS 251 6 1105 Housing Female 10 Sek Sah 20052 CS 237 3 J106 Housing Female 5 BERG 20370 CS 251 J107 Housing Female 5 BERG 20370 CS 251 21
60. bient temperature is different from 25 C NOTE This procedure is intended to verify only the basic accuracy of the Model 160B in voltage current and resistance modes Test equipment accuracy is specified at X10 better than measurement accuracy MAINTENANCE MAINTENANCE a Battery Check With Model 1688A Battery Pack installed 1 Check for proper installation of ndiv dual cells in the battery pack making note of polarity of cells as shown in Figure 6 2 Set Power Switch to BAT 3 Connect Voltmeter A between test point B and LO to verify the 11 8 4 volt supply Con nect Voltmeter A to test point A co verify the Button cell 16 8 volt supply Voltage readings at each test point should be in accordance with Table 6 2 IMPORTANT The instrument must be operated in the BAT mode in order to obtain a valid battery con dition at test points A and B This will ensure that the batteries are supplying power to the instrument If the voltages are measured when the Model 160B is operated in the LINE mode a d fferent reading may be observed since the batteries are not connect ed and therefore do not supply power to the instrument TABLE 6 1 Recommended Test Equipment for Performance Verification Model Item Description Minimum Specification Manufacturer A Voltmeter Digital 10 00V 8 0 22 Keithley 168 B Voltage Source 1 10 100 1000V dc 0 0052 Fluke 343A C Voltage Divider
61. cessary to repeat steps d e are interrelated and dependent on prior calibration and g one or more times steps d DC Voltage Calibration 3 DC Cal and DC Cal Adjustment 1 Voltage Zero and Offset Current Zero Adjust ment a Change Divider K setting to 0 1 ratio a Select ImV range b Apply a 100mV signal to the Model 1608 input b Place a short low thermal copper across the input terminals c Adjust Cal R137 for a reading of 100 0 at the Model 160B display c Connect Voltmeter I to the Model 160B Analog Output d Apply a 100mV signal d Adjust front panel Zero Control 8114 for e Adjust DC Cal R134 for a reading of a reading of t0 3mV at Voltmeter I 100 0 at the Model 1608 display e Remove the short across the Model 160B in NOTE put terminals If the readings at full range are considerably f Adjust Offset Current Zero R121 for a out before adjustment then steps 2 and 3 reading of 20 at Voltmeter I Should be repeated 1174 39 MAINTENANCE MODEL 1608 FIGURE 30 Location of Calibration Adjustments 49 1174 MAINTENANCE MODEL 1608 ANALOG OUTPUT 1V 5V TO MODEL 1602B Location of Test Points FIGURE 31 41 1174 MAINTENANCE MODEL 160 e Ohms Calibration 2 Ohms Reference Accuracy Adjustment 1 100mV Reference Adjustment a Set Voltage Source J to 2V and set Divider K to 0 1 ratio a Leave th
62. column shown here allows the user to verify that the instrument will meet published specs for a period of 6 months R163 may or may not be installed See schematic 26590E 1174 43 MAINTENANCE MODEL 1608 FIGURE 32 Location of Chassis Connections F202 LINE F201 Fuses 1 8 AMPERE F101 CURRENT PROTECTION FUSE FIGURE 33 Location of Fuses 44 1174 MODEL 160B REPLACEABLE PARTS SECTION 7 REPLACEABLE PARTS 7 1 GENERAL This section contains information for ordering replacement parts The parts list is arranged alphameric order of their Circuit Desig nations 1 2 ORDERING INFORMATION To place an order or to obtain information concerning replacement parts con tact your Keithley representative or the factory See the inside front cover of the manual for addresses When ordering include the following information a Instrument Model Number b Instrument Serial Number c Part Description d Circuit Designation if applicable e Keithley Stock Part Number TABLE 7 1 Abbreviations Symbols and Designators 7 3 SCHEMATICS a Input Amplifier and A D Converter 26590E This schematic describes the input amplifier range switching and A D Converter circuitry Circuit designation series is 100 b Digital Logic Display and Power Supply 26584E This schematic describes the display drive and power supply circuitry Circuit designa tion series is 200 c Mo
63. d 1000 a How to Open Instrument Turn the Model 160B mA ranges are within the tolerances given in Table over so that the bottom cover is facing up Loosen 6 5 the four slotted screws on the bottom panel the screw heads should come up to about the top of the holes Turn the instrument top side up Carefully lift off the top cover and disconnect the wires to the Analog Output CAUTION Care should be taken to avoid contact with line voltages at various points on the pc board when the line voltage cord is connec ted 0875 37 MAINTENANCE MODEL 160B TOP COVER 26545C METALCAL MC 212 SPACER 257628 FRONT PANEL KNOB KNOB KN 37 25539A 25537A KN 33 METALCAL MC 213 OPE BOTTOM VER 25727 INSERT 26090A 219 2 REQUIRED HANDLE 257290 FIGURE 29 and Bottom Cover Assembly 38 1277 MODEL 160 MAINTENANCE TABLE 6 6 Recommended Test Equipment for Calibration Item Description Minimum Specification Manufacturer Model Voltmeter Digital 100 0 015 Data Precision 2540AL lv 0 012 J Voltage Source 1v 8 0 005 Fluke 343A K Voltage Divider 10 1 8 0 0052 ESI 622A 10K 1000 1 0 0252 b Power Supply Check The power supply voltages NOTE can be checked with Voltmeter I from Table 6 6 There is a long time constant for this adiust l 45V Regulated Supply Check the Line Voltage ment due to the 10 9 input impedance and the Switche
64. d by an AND gate as shown in Figure 27 The reference current is adjusted so that a voltage of 1V at the integrator input 161 produces a total discharge period containing 1000 clock pulses For R161A and R161B each having a value of lk the reference current must be adjusted to a value of ap proximately to produce the proper conversion ac na 4 THEORY OF OPERATION TIMING CIRCUITS A D CONVERTER R161A 28 BCD COUNTERS LATCHES FIGURE 26 LSI Block Diagram INTEGRATOR THRESHOLD DETECTOR R1618 FIGURE 27 A D Converter Diagram MODEL 160B MULTIPLEX OUTPUT MULTIPLEX 7 SEGMENT CIRCUITRY DECODER DISPLAY OUTPUTS TO DISPLAY LSI CIRCUITRY 1174 MODEL 160B IDENTIFICATION OF MULTIPLEX LINES THEORY OF OPERATION e dp e IDENTIFICATION OF SEGMENTS FIGURE 28 Identification of Segments and Multiplex Lines curacy Once the reference current is set an input of 250mV is represented as 250 counts out of 2016 and 1 999V is represented as 1999 counts out of 2016 An input of 2V or greater causes the 3 least signi ficant digits to blank NOTE One complete conversion cycie is 2048 counts The BDC counter is able to count to 2016 be fore it 15 stopped During the remaining 32 counts the information in the BDC counter is transferred into latches and then the BCD counter is reset to zero 2048 counts at a clock frequency of 9680 Hz results in a total convers
65. dc voltage in seven ranges lmV lOmV 100 1V 10V 1007 LOOOV Maximum dc input is 1200V dc peak ac a How to Select Range Function and range is selected by rotating the Range Switch to the appro priate position Three positions are direct reading in millivolts mV four positions are direct read ing in volts V Decimal point is selected by the Range Switch Polarity is automatically displayed If the input signal exceeds twice full range the display blanks 3 least significant digits to in dicate an overrange condition TABLE 3 2 Voltage Ranges Displayed Max Displa Maximum allowable input is 1200V de plus peak ac even though display can be read beyond 1200V 1174 b How to Determine Accuracy The Model 1608 ac curacy is 0 17 of reading 1 digit For example a display reading of 1 000 volt dc will have an un certainty of 10 1 1 digit or 002 volts in put resistance in the dc mode is 10 megohms Meas urements from relatively high source resistances could cause an additional reading error The amount of error due to loading can be determined by the following relationship X error 100 x Rg Rg 107 where Rg source resistance in ohms For example a source resistance of 10 000 ohms will result in a loading error of approximately 0 1Z of reading NOTE The input current of the 1608 can also cause reading errors on the most sensitive voltage ranges when hig
66. del 1602B Digital Output 26654E This schematic describes the digital output for Model 1608 Circuit designation series is 300 A ampere A assembly BT battery capacitor carbon variable Cer D ceramic disc cer T ceramic trimmer coefficient com common comp composition DCb deposited carbon Desig designation D diode all types DPDT double pole double throw DPST double pole single throw ps lamp elect electrolytic encap encapsolated EAL electrolytic aluminum ETS electrolytic tubular ETT electrolytic tantalum F farad F gt 1077 farad FET effect transistor fempto 10717 FL filter fxd fixed Fig figure F fuse GaAs gallium arsenide glass enclosed carbon Ge germanium grd ground H henry uH 1076 henry Hg Mercury ilz hertz cycles per second 10 inside diameter in inches 1 ia 25 4 mm 3 jack k kito 103 kilohm 103 kHz kilohertz 10 Hz K relay L inductor lin linear log logarithmic LSI large scale integrated circuit M meter or Meg 10 m milli 1073 Meg megohm 1002 i milliamperes 10 3 mS millisecond 1075 seconds 1072 i metal film mir manufacturer meg mount ing My My Lar nA nanoampere 10794 no number NC normally closed NO normally open 1 ohms obd order by description outside fgmeter p pico 10774 p peak pc printed circutt pF picofarad
67. digits Resistor Network digits Resistor Network This table is to be considered as an extension of Table 6 3 The modified Tolerance on Reading column shown here allows the user to verify that the instrument will meet published specs for a per iod of 6 months TABLE 6 9 Accuracy Check for Resistance Range Tolerance on Readin Principle Component Involved 1 9 3 1 2 digits R147 99 9 10 3 digits R147 99 92 100 3 digits R147 99 97 1 3 digits R148 10 ki 3 digits 8149 10 2 100 43 digits 8150 100k 1 3 digits 8151 10 0 3 digits R152 10 9 100 90 digits R153 LOOMS 1000 M2 250 digits R154 910 0 This table is to be considered as an extension of Table 6 4 The modified Tolerance on Reading column shown here allows the user to verify that the instrument will meet published specs for a period of 6 months TABLE 6 10 Accuracy Check for Current Range Tolerance on Readin le Component Involved 10 nA 4 digits R145 1M amp 100 nA 2 1 2 digits R146 100k2 l uA 2 1 2 digits R139 10k8 and CR108 10 uA 2 1 2 digits R140 100 uA 2 1 2 digits R141 1000 l mA 2 1 2 digits R142 102 10 mA 2 1 2 digits R143 0 9970 100 mA 3 1 2 digits R144 0 09872 and R163 201 1000 mA 3 1 2 digits R144 0 09879 and R163 200 This table is to be considered as an extension of Table 6 5 The modified Tolerance on Reading
68. dr R130 4 99k2 1 0 12W 2 IRC CEA TO 4 99K R88 4 99K 1 8131 12 167 1 0 12 MtF IRC CEA TO 12 1K R88 12 1K 1 8132 lko 102 0 25W Comp CB 102 10 R76 1K R133 3 3k2 10 0 25W Comp gt 0 CB 332 102 R76 3 3K 2 R134 5000 0 5W E s 72PMR 500 RP97 500 1 8135 10 0 0 5W Var 72PMR 10K RP97 LOK 2 R136 10kQ 0 5W Var BECK 72PMR 10K RP97 10K R137 0 5W Var E 7 2PMR 1K RP97 1K R138 2 1 0 12W MtF a IRC CEA TO 2K R88 2K 1 R139 10 0 0 02 0 3W MtF VISH V53 10k2 R183 10K 2 R140 0 1 0 5W MtF DALE 1 2 R 169 1K 1 R141 1000 0 1 0 12W vt DALE MFF 1 8 100 R168 100 1 8142 10 02 0 14 54 RCL T5 10 0 R185 10 0 l R143 0 9972 0 1 5W a RCL T5 0 997 R185 0 997 1 49 127 REPLACEABLE PARTS RESISTORS Cont d MODEL 160B Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty R144 0 09870 0 1 SW wx e gt REL T5 0 0987 R185 0 0987 l R145 1 0 0 1 0 5W lt s c ate DALE 1 2 9 1 169 2 R146 100kn 0 12 0 5W MEF et DALE MFF 1 2 T9 100K R169 100K 2 R147 99 90 0 12 0 12W DALE MFF 1 8 99 9 R168 99 9 8148 1 0 0 12 0 12W 4 DALE MFF 1 8 1K R168 1K 1 R149 10 0 0 12 O
69. e RTT TEXAS 14914 RF 28 10 CR302 Rectifier 75m 75V TEXAS 1N914 RF 28 CR303 Rectifier 75mA 75 TEXAS 1N914 RF 28 45 CR304 Rectifier 75mA 75 TEXAS 13914 RF 28 CR305 Rectifier 75mA 75 TEXAS 18914 RF 28 CR306 Rectifier 75mA 75V lt lt s 4 s 9 s 0 o TEXAS 13914 RF 28 ose CR307 Rectifier 75mA 75 TEXAS 18914 28 s CR308 Rectifier 75mA 75 TEXAS 1N914 RF 28 4 CR309 Rectifier 75mA 75 2 TEXAS 1N914 RF 28 s CR310 Rectifier 75mA 75V lt lt s a lt q s on on on TEXAS 1N914 RF 28 CONNECTORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty J301 Not Used 5 24 Low SS W Wayka eee a UE Re 3302 Digital Output 37 pins AMP 205209 1 CS 301 1 J303 Eemal S pings 55 5 Aa wa BERG 65039 040 5 251 1 P301 Cable Assembly Custom KI ee niet 26424A 2 1 P302 Mating Connector Digital Output 37 pins CAN DC 37B CS 302 1 Connector Cover Hood for 302 2 CAN DC 512K1 1 CS 300 1 TRANSISTORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty Q301 NPN Case 0 92 MOT 2N5087 TG 62 20 Q302 NPN 92 v lt 5 y De R o MOT 2N5087 TG 62 PES Q303 NPN Case 92 web v to
70. e Model 1608 set on the 100 Range leave Voltage Source J and Divider K b Apply a 200mV to the Model 160B input connected to the Model 160B input c Adjust the Ohms Ref Accuracy trimpot b Set Voltage Source J to OV and set R110 for 300 60 at Voltmeter I Divider X to 0 output c Connect Voltmeter I to TP101 100mV Ref d Adjust the 100mV Adj trimpot 8105 for 100mV 20uV at Voltmeter I TABLE 6 7 Summary of Calibration Adjustments Source Source Display Test Equipment Adjustment Name and Input Accuracy Range Reading Desig Reading Circuit Desig Low Thermal short 1 mV T Analog Output Front Panel Zero set to 0 3mV R114 Open 1 mV 1 Analog Output Offset Current Zero set to 0 20mV R121 1mV 52 100 01 0 Display Zero R136 lmV 5 100 01 0 Rectifier Zero R135 100mV 01 100 100 0 DC Cal R137 100mV x 01Z 100 mV 100 0 DC Cal R134 Short 100 mV 1 01 set to 100mV adj R105 LOOmV 20uV 200mV 4 01 100 T TP101 set to Ohms Ref Accuracy 300mV 60uV R110 22 RM AD QUE 42 1174 MODEL 160B MAINTENANCE TABLE 6 8 Accuracy Check for DC Voltage Tolerance on Readin Principle Component Involved digits Resistor Network digits Resistor Network digits Resistor Network digits Resistor Network digits Resistor Network
71. ector MODEL 160B Exploded View of Model 1608 16028 To install the Model 16028 turn the Model 1608 over that the bottom cover faces up Locate and loosen four slotted screws as shown in Figure 4 The screws are captive and should not be completely removed Once the screws are loosened hold top and bottom covers together and turn Model 160B so that the top cover is up Carefully lift off the top cover and disconnect the wires to the Analog Output Locate 16 pin receptacle J201 on the main circuit board PC 349 Plug the mating connector P301 from the Model 1602 into J201 after checking that pin numbers corres ponding Locate 3 pin plug P208 on the main circuit board PC 349 Connect J303 from the Model 1602 to 208 Be sure that the A of P208 lines up with the A of 4303 Place Model 1602B board on four spacers with cables positioned as shown in Figure 17 Remove digital output cover plate from Model 160B top cover Place top cover back on instrument after reconnecting Analog Output wires Turn instrument over and tighten four slotted screws c Pin Identification of Rear Panel Digital Output The Model 1602B uses a 37 pin connector J302 to provide all input and output connections to external equipment Pins are identified as shown in Table 3 7 CAUTION DISCONNECT LINE CORD BEFORE OPENING THE TOP AND BOTTOM COVER LINE VOLTAGE ON THE CHASSIS REPRESENTS A SHOCK HAZARD 16 0976 MODEL 160B
72. ent itself c Other Considerations 1 Voltmeter Measurements Use shielded input leads when source resistances are greater than 1 kilohm or when long input cables are used 2 Current Measurements the mA and u cur rent ranges no special shielding precautions need be taken However on the 100 and 10 nanoampere ranges shielded input leads are recommended 3 Resistance Measurements Shielding of input leads and source are recommended for measurements on the 10 megohm through 1000 megohm ranges to pre vent erroneous readings 1174 MODEL 160B OPERATING INSTRUCTIONS FIGURE 12 Voltage Measurements Using Model 1601 AC DC Probe CURRENT TERMINALS VOLTAGE TERMINALS VOLTAGE LEADS FURNISHED FIGURE 13 Current Measurements Using Model 1651 Shunt 1174 13 OPERATING INSTRUCTIONS gt lt SOURCE lt RESISTANCE EXTERNAL JL SOURCE EN 1000V DC GROUND FIGURE l4 3 13 HOW TO USE THE ANALOG OUTPUT The Model 160B has an analog output of 1 volt at full range non inverting at up to l milliampere 2mA at 2 volts for recording or monitoring purposes Also the analog output enables the Model 160B to be used as a low noise low drift DC amplifier TABLE 3 5 Gain at ANALOG OUTPUT Full Range Output l mV X1000 10 mV X100 100 mV X10 For off ground operation the analog output should be connected only to equipment capable of operating off ground also The low side of
73. ermined by R209 R210 and 8211 4 4 POWER SUPPLY The Model 1608 uses either line power or battery power when the Model 1668A is in stalled a Line Power Transformer T201 has two tapped primary windings which are connected in series or in parallel depending on the position of line switches 5201 202 Fuse F201 is in series with winding 4 5 6 For all settings Fuse F202 is connected only when winding 1 2 3 is connected in parallel with wind ing 4 5 6 secondary of 7201 has two tapped wind ings The lower taps 11 and 10 8 and 7 are used in line mode The upper taps 12 and 10 9 and 7 are used in charge mode 1 5V Supply LINE operation the ac volt age between transformer leads 10 and 11 is full wave rectified by CR203 The filtered full wave dc volt age approximately 10V is regulated by integrated circuit U207 The output regulated voltage is 5V 45 MODEL 160B 2 12V Supply LINE operation the voltage between transformer leads 7 and 8 is full wave rec tified by 204 The filtered full wave dc voltage approximately 18V is regulated by integrated cir cuit U208 The regulated output voltage is 12V 57 b Battery Power When BATTERY mode is selected the Model 1668A Battery Pack is connected into the n puts of U207 and U208 while the line voltage is dis connected at the secondary The 8 4V batteries pro vide input power for the 5V supply The 16 8V bat teries provide input
74. g A particular strobe circuit includes a diode a lOkQ pull up resistor and a CMOS Buffer gate The diode is used to allow volt ages up to 15 volts to control the strobe circuit The output of a particular Buffer gate drives one in put of each 2 Input NOR gate in a particular output data group A logic 1 at the input of a strobe circuit produces a logic 1 at one input of a NOR gate this produces a logic 0 at the output of the NOR gate regardless of the logic state of the data at the other input of the NOR gate A logic O from the NOR gate shuts off the output transistors 1174 THEORY OF OPERATION e Timer Circuit for Flag Flag The timing cir cuit for tie Flag uses a monolithic bipolar integra ted circuit U306 This timer is hooked up to op erate in a monostable mode It is triggered by rhe negative going edge of the CN or COUNT NOW wave form CN signal is generated in the LSI cir cuit of the Model 160B and its negative going edge indicates that the counting cycle for a particular A to D conversion is complete Once the timer is triggered ts output remains at logic 1 for a per iod of time determined by R301 100k and C301 9 1 uF in this case lOmS The lOmS high time allows the Latches in the Model 160 51 circuit to be up dated and the latches n the Digital Output to be updated The timer output goes to other circuitry which is controlled by the Flag Reset Line f
75. ge sensitivity on the 100mV through 1000V ranges the 10X the full range sensitivity the and lOmV ranges will cause clipping in the AC section of the Model 160B input amplifier For this reason shielding is re commended when making sensitive DC voltage measure ments or when making measurements from high source impedances See Shielding Section 3 12 The in strument is also capable of rejecting frequencies other than power line frequencies There is one pro blem to consider however the input amplifier of the Model 160B uses a modulator to convert DC signals to AC signals before amplification The drive frequency of this modulator is 220 Hz nominally approx 5 Interfering AC signals with frequencies equal to the modulator drive frequency or multiples thereof wil appear as modulated DC and produce large DC errors 3 12 SHIELDING a Electric Fields Shielding is usually neces sary when the instrument is in the presence of very large a c fields or when very sensitive measurements are being made The shields of the measurement cir cuit and leads should be connected together to ground at only one point This provides a tree configura tion which minimizes ground loops b Magnetic Fields Magnetic shielding is useful where very large magnetic fields are present Shield ing which is available in the form of plates foil or cables can be used to shield the measuring cir cuit the lead wires or the instrum
76. gnificant DC error signals can be produced at the output of the overall amplifier 4 Modulator Circuit This circuit converts an input dc signal to an ac signal with a fundamental frequency component of approx 220 Hz The fre quency of 220 Hz was chosen because this frequency is not harmonically related to either 50 Hz or 60 Hz The circuit utilizes a dual MOS FET Q102A and 01028 connected in series shunt configura tion This type of series shunt modulator main tains high input impedance 5 AC Amplifier The ac amplifier uses a low noise integrated circuit 0104 The amplifier feed back network provides a gain of approx 2000 at the modulating frequency of 220 Hz while maintaining a gain of 1 for amplifier 0104 de offset voltages 6 Demodulator Circuit The demodulator is syn chronized with the input modulator A JFET Q103 with low on resistance is used to alternately atten uate or pass the signal present at the output of ac amplifier 0104 The negative portions of the 220 Hz ac signal are allowed to pass which produces a half wave rectified negative dc signal at the in put to dc amplifier U105 7 DC Amplifier This amplifier is composed of resistors R128 and R129 capacitors C113 and C114 and integrated circuit 0105 The integrated cir cuit provides sufficient gain to bring the total open loop dc gain of the overall amplifier to a minimum of about 20 million The feedback capaci tor C113 and Cll4 in series
77. h source resistances are pre sent For example an input current of 10 and a source resistance of 1 0 produce an error voltage of 10 c Maximum Allowable Input The maximum input to the Model 160B is 1200V dc peak ac lOmV and 100mV ranges the maximum continuous input is 600V 12007 momentary dc peak ac The Model 1608 can display dc voltages greater than 1200V but dam age to the input is possible OPERATING INSTRUCTIONS IMPORTANT The Model 160 provides ac rejection NMRR of greater than 60 dB on the highest range However a large ac signal superimposed on dc level could cause damage if the input to the Model 160B exceeds 1200 volts dc peak ac d How to Zero the Display To accurately zero the instrument place a low thermal short such as a piece of clean copper wire across the input termin als set the Range Svitch to the lmV range and ad just the front panel Zero control for a flashing sign at the display The display should then read 000 with some flicker of the least significant digit due to noise and A D converter uncertainty Once the zero has been set accurately there should be little reason to rezero the instrument again soon when making measurements on the lOmV through 1000V ranges The time stability of the zero setting is excellent and in applications requiring continuous operation of the Model 1608 the zero setting will hold for months The front panel Zero cont
78. he 100mV RANGE Power dissipated in the shunt 15 2 5 watts at 50 amperes 3 8 NOISE CONSIDERATIONS The limit of resolution in voltage and current measurements is determined largely by the noise generated in the source Stray low level noise is present in some form in nearly all electrical circuits The instrument does not distin guish between stray and signal voltages since it meas ures the net voltage When using the lmV and lOmV ranges consider the presence of Low level electri cal phenomena such as thermocouples thermoelectric effect flexing of coaxial cables triboelectric effect apparent residual charges on capacitors dielectric absorption and battery action of two terminals galvanic action 3 9 THERMAL EMFS Thermal emfs thermoelectric potentials are generated by thermal differences be tween two junctions of dissimilar metals To mini mize the drift caused by thermal emfs use copper leads to connect the circuit to the instrument The front panel ZERO control can be used to buck out a constant thermal offset voltage if necessary The Keithley accessory Model 1483 Low Thermal Connection Kit contains all necessary materials for making very low thermal copper crimp connections for minimizing thermal effects 3 10 MAGNETIC FIELDS The presence of strong mag netic fields can be a potential source of ac noise Magnetic flux lines which cut a conductor can produce large a c noise especially at power line frequencies
79. he Model 1600 High Voltage Probe may be used with a voltmeter havinga nominal input resistance of 10 megohms in the de volts function The division ratio is 1000 1 The maximum voltage which can be measured is 40 kilovolts VOLTAGE RANGE 0 to 40 000 volts dc INPUT RESISTANCE 1000 megohms DIVISION RATIO 1000 1 RATIO ACCURACY WITH 10M LOAD 1 5Z at 25kV decreasing to 2 0 at 20kV and 30kV 3 0 at and 40kV and 14 0 at LlkV RATIO STABILITY 0 01 C 0 1 per year HEATING EFFECTS Self heating due to application of high voltage for periods in excess of 1 minute will cause a maximum of 0 2 additional error at 40kV error is less at lower voltages ENVIRONMENT 0 C to 50 0 to 80 relative humidity up to 35 C Storage 25 to 70 C DIMENSIONS WEIGHT 3 in maximum diameter x 15 1 4 in long 76 x 387 mm 4 1 2 ft 1 4 m cable and ground clip lead to banana plug Net Weight 12 oz 341 g Ac response ar lkV is flat within 10Z from 20 Hz to 120 Hz Division ratio is depen dent on input impedance of multimeter used E PA DT 1277 3 ACCESSORIES MODEL 1608 __ _ __ __ _____ _____ _ _____ _____________ ___ _ ___ _ NN NET RON UN c _ ___ RE II Model 1682 RF Probe Description The Model 1682 is an accessory probe Contents which adapts the Model 160B for measurements to LOOMHz Qt
80. inal driven and a source impedance of 1 a 10007 60 Hz common mode signal will produce voltage of only 100mV p p across the Model 160B in put terminals This 100mV p p signal will be further rejected by the input amplifier and A D converter so that the total rejection at the digital display is at least 140 dB At lower levels of AC common mode signals the total rejection at the display is even greater For example 60 Hz 100 p p signal should produce only about 1 digit error on the Range for a total rejection of approx 160 dB HI driven 1k2 source impedance With both AC and DC common mode signals rejection is much greater than specified when the Model 160B LO terminal is driven rather than the HI terminal Where there is a need for even greater isolation from LO to power l ne ground or where there is a need to float at poten tials greater than 1200 volts above power line ground the Model 1688A Battery Pack should be used 0976 MODEL 1608 v7 fct e usui ee iei Fa ens 9900000000999009900 e OPERATINC INSTRUCTIONS DIGITAL OUTPUT CONNECTOR J302 TYPICAL INSTALLATION OF PULL UP RESISTORS NOT FURNISHED neum JD FIGURE 15 Model 1602B Digital Output TABLE 3 6 Specifications for Model 1602B Digital Output DIGITAL OUTPUT BCD open collector positive logic represents each of 3 digits overrange digit over lo
81. ion time of approximately 0 21 seconds which is equivalent to about 5 readings sec d Clock The clock circuit makes use of an IC timer 0202 hooked up for astable operation Resis tors R205 and R206 together with capacitor C201 set up a non symmetrical square wave with a nominal fre quency of 9680 Hz and a duty cycle of about 54 0201 along with R202 R203 and R204 is used to nvert the output of U202 e Display The Model 160B digital readout is made up of three LED seven segment displays 05202 DS203 and 05204 and one LED 1 display 05201 1 Display Multiplexing The LED displays are multiplexed to minimize the number of interconnec tions simplify the drive circuitry and reduce power consumption The timing for the multiplexing 0976 is determined by the LSI circuit U201 and is up such that each multiplex line is high for 8 clock pulses approximately 825 5 and low for 24 clock pulses The four multiplex lines are de signated as TO Tl T2 and T3 and each line con trols an LED display See Figure 28 Circuit opera tion during a particular multiplexing interval say TO is as follows When TO is high the output of U203A is low This produces a current in R218B of approximately lOmA which is sufficient to drive 0202 into saturation and effectively connect 05201 to the 5V power line Simultaneously the LSI circuit supplies the correct digital information for DS201 to the display segment dr
82. ivers The same circuit action then occurs during the other multi plexing intervals 2 and 3 2 Display Drive The display drivers de signed to handle a variety of LED common anode dis plays Because constant current drivers are used displays with different voltage drops per segment can be driven without changing the circuit power consumption The drivers take the same current from the 45V power supply regardless of whether the display segment drop is 1V or 3 5V Actual operation of a particular segment segment A for example is as follows When the A line of LSI circuit U201 is high then the open collector out put of buffer U204A is shut off As a result the voltage at pin 5 of resistor network R217 is approx imately 1 3V which is also the voltage at pin 9 of transistor array U205 Assuming base to em itter voltage of 0 7 then the voltage at pin 10 of 0205 is approximately 0 6 this voltage gener ates a 15mA current in the 402 emitter resistor 29 THEORY OF OPERATION When the A line of U201 is low then the output of U204A is also low and the transistor current source pins 9 10 and 11 of U205 controlled by 0204 is shut off Transistor 0207 and its assoc iated circuitry duplicates the operation of the other six transistor current sources The decimal point lines of DS202 DS203 and DS204 are controlled by the Range Switch and the currents for the decimal points are det
83. lly remove the top cover to gain access to the printed circuit board Two wires that connect to the Analog Output must be disconnected at the PC board before the top cover can be set aside Check to see that the four insulating spacers are in posi tion on the printed circuit board Place the Model 1688A Battery Pack in position on the spacers with the cable oriented as shown in Figure 8 Plug the 4 wire connector J205 into the mating receptacle P205 taking care to orient the connector as shown in Figure 8 After the Battery Pack is in stalled replace the top cover Turn over the in strument with bottom cover facing up and tighten down the four slotted head screws TABLE 2 2 Summary of Batteries Used in Model 1688A Rechargeable cell 7 1 2V 2 AMP HR Keithley Part No Rechargeable battery pack 16 8V 225 AMP HR 0976 MODEL 1608 INTTIAL PREPARATION 8 BAT TEST FIGURE 9 Battery Test Location 2 How to Check Batteries Valid only in BAT mode The Model 1608 provides two test points and B located on the bottom of the instrument as shown in Figure 9 These test points permit a con venient check of the condition of the internal Bat tery Pack without need to remove the Model 160B cover The voltage at test points A or B may be measured using the Model 1608 or any other compar able voltage measuring instrument To check the voltages at test points A or B select the BAT mode connect
84. mV or 100mV full attenuates 10 and 1000V signals to 100 p OHMMETER DIGITAL CIRCUITRY 7 DISPLAY HI ANALOG boss i SWITCHING amp amp ATTENUATOR AMPLIFIER CONVERTER Uu CURRENT OPTIONAL SHUNT DIGITAL RESISTORS OUTPUT 1V OUTPUT FIGURE 21 Overall Block Diagram 1174 THEORY OF OPERATION TABLE 4 1 MODEL 160B Summary of Voltage Sensitivity Attenuator Amplifier Full Range Amplifier Full Range Range Setting Sensitivity Gain DC Output l mV 10 mV 10 100 mV 1 V 1 100 10 v 1 100 100 V 1 10 000 1000 V 1 10 000 3 Filter Network Basically the filter is a l section RC low pass filter made up of R116 R117 and 104 R116 and R117 in series have a nominal resistance value of 112k At 50 Hz C104 5AuF has a reactance of approx 6kQ and with the 112kQ produces an attenuation of approx 20 to l This attenuation gives the Model 160B a normal mode re jection spec of 60 dB above 1 digit on the l00mV range as an example 60 dB above 1 digit means that the Model 1608 can reject a 100mV 50 Hz signal on the 100 range with no more than a 1 digit error 100 p p at 50 Hz would be reduced to 5mV p p at the output of the filter This 5mV p p after chopping and amplifying is enough to cause amplifier U104 to reach its maximum allowed output level signal greater than 5mWV at the output of the filter causes 0104 to saturate When saturation occurs si
85. n alo ultr wje Wl eeoa 111 SPECIFICATIONS MODEL 160 8 5 216 DIMENSIONS IN INCHES FIGURE 1 Dimensional Data iv 1174 MODEL 160B SPECIFICATIONS SPECIFICATIONS Calibrated at 25 3 C Warranted for 1 year AS A DC VOLTMETER MAX ALLOWABLE MAXIMUM ACCURACY INPUT TEMPERATURE COEFFICIENT INPUT RANGE READING of rdg of RESISTANCE r ol rdg of dc peak 1 1999 01 01 001 901 302 10 19 99 0 1 0 1 10 MA 001 001 100 mv 199 9 01 01 001 gare 1 1999 v 01 01 10 ME 001 901 250 gt 10 1999 v 01 01 001 901 1290 v 100 1999 V 01 01 10 001 001 1200 V 1000 1200 0 1 0 1 19 001 001 1200 NORMAL MODE REJECTION RATIO Greater than 80 dB above one digit on the 1 millivolt and 10 millivott ranges and greater than 60 dB above one digit on higher ranges for voltages of line frequency or twice line frequency with at least 1 of full range dc applied ZERO STABILITY 0 1 microvolts per 1200 y momenta COMMON MODE REJECTION RATIO 1 k unbalance Greater than 140 dB at dc and 40 to 200 Hz ac with at leas 1 of full range dc applied 1000 voits dc peak to peak ac maximum SETTLING TIME Less than 2 seconds to within 0 1 of finai reading except less than 4 seconds on the mV
86. nt Panel Controls Location of Protection Fuse Voltage Measurements Using Model 1601 AC DC Probe Current Measurements Using Model 1651 Shunt Floating Operation Model 1602B Digital Output Exploded View of Model 160 16028 Installation of Model 16028 Rear Panel Digital Output Connector Timing Diagram for Model 1602B Rack Mounting of Model 160B Overall Block Diagram DC Voltage Operation Resistance Operation Current Operation Absolute Value Detector LSI Block Diagram A D Converter Diagram Identification of Segments and Multiplex Lines Top and Bottom Cover Assembly Location of Calibration Adjustments Location of Test Points Location of Chassis Connections Location of Fuses Case Outline Integrated Circuits Case Outline Integrated Circuits Case Outline Integrated Circuits Case Outline Integrated Circuits Case Outline Transistors Case Outline Thick Film Networks Case Outline Thick Film Networks Case Outline Custom 151 Component Layout PC 349 Component Layout PC 352 ILLUSTRATIONS No II k lt Ke PTO olson fut Slo Z Land lt vn w
87. nt range of approximately 450yVolts A typical Model 160B has an internal offset of about 100uVolts in the chopper amplifier Hence adjust ing the Front Panel Zero from end to end will typi cally produce about 125yVolts and 325uVolts This extra adjustment at the negative end of the range allows sizeable positive offsets to be compensated for 8 the case when the Zero is used for test lead compensation on the low ohms Ranges 200mQ of test lead resistance will produce 200yVolts of zero offset which can be bucked out by the Zero con trol See also Section 3 5d Zeroing of the chopper amplifier output is actually accomplished by having the Zero circuit either source or sink whatever current is present in feedback resistor R160D For example an offset voltage of LllluV on the feedback line produces a current of 1 in re sistor 1600 111 1359 A voltage of luVolt at the wiper of Zero potentiometer R114 will produce an equal current of 1 in resistor R115 IMQ With this zeroing scheme for the chopper amplifier output to be at zero the voltage at the feedback line will always be offset from the voltage at the input by a constant say for example 1lluVolts The feedback line connects to the junction of Rl60C and R160D 1174 MODEL 160B THEORY OF OPERATION ANALOG AMPLIFIER AC AMPLIFIER DC AMPLIFIER INPUT HI ATTENUATOR INPUT LO RANGE SWITCHING FIGURE 22 DC Voltage Operation INPUT H
88. nts and a current source for resistance measure of the dc output to provide overall gain accuracy ments 2 analog to digital converter and stability b The analog amplifier is a variable gain chopper 1 Output Resistor Divider This divider is amplifter composed of resistors R160A R160B R160C and 1600 These resistors are packaged together as The analog to digital converter is charge a single network and the four resistors are matched balancing type converter with five readings second to within 0 02 of one another at approx 23 C conversion rate BCD outputs and external control This divider supplies dc feedback to the amplifier options are available when used with the Model 1602B input and sets up the three gains of the Digital Output Kit amplifier X10 X100 and X1000 4 2 ANALOG AMPLIFIER CIRCUITRY The analog ampli 2 Input Resistor Divider This divider is male fier is shown in the simplified block diagram Figure up of resistors RI59A 1598 and RI59C These re 21 sistors are packaged together as a single networx and the three resistors are matched to within 2 022 a Voltage Amplifier The amplifier has a full of one another at approx 23 C They are matched range sensitivity variable from 1 millivolt to 100 to within 0 054 with 1200 VDC applied This divi millivolts Above 100 millivolts the input signal der attenuates and 100V signals to lOmV and ic is divided down to either the lO
89. ov iy oem MOT 2N5087 TG 62 Q304 NPN Case 70 92 MOT 2N5087 TG 62 ph Q305 NPN Case 70 92 le a MOT 2N5087 TG 62 Fa Q306 NPN Case 70 922 MOT 2N5087 16 62 n Q307 NPN Case 70 92 MOT 2N5087 TG 62 w Q308 NPN Case 10 92 MOT 2N5087 TG 62 43 0309 NPN 10 922 MOT 2N5087 TG 62 C310 NPN Case 0 922 MOT 2N5087 TG 62 2 C311 NPN Case 70 92 MOT 2N5087 TG 62 m C312 NPN 70 922 MOT 2N5087 TG 62 sos C313 NPN 92 x v e 4o o 4 ov a MOT 2N5087 TG 62 PP C314 NPN Case T0 92 5 v OS e MOT 2N5087 TG 62 315 NPN Case 70 92 MOT 2N5087 TG 62 ss C316 NPN Case 92 4 4 amp s 4 s 4 4 MOT 2N5087 TG 62 zs C317 NPN Case 702 92 MOT 2N5087 TG 62 s C318 NPN Case 10 92 x amp amp i 0 o9 v Y 4 MOT 2N5087 TG 62 s C319 NPN Case 02 92 MOT 2N5087 TG 62 4 C320 NEN Case 170 9224 0204 cay no eve Rs MOT 2N5087 TG 62 52 1174 MODEL 1602B REPLACEABLE PARTS RESTSTORS Circuit Mfr Mfr Keithley Desig Description Code Desig Part No Qty R301 100 1 0 12W ae pelt IRC CEA TO 100k 4 R88 100K 1 R302 IDkd 107 0 25W A B CB 103 1
90. pprox imately 200mS regardless of whether Flag Reset is used The BCD Hold should be activated after Flag has gone from low to high the BCD hold Should be released after the Flag has gone first from high to low and then from low to high 1174 OPERATING INSTRUCTIONS NOTE The BCD Hold has no control over the DP decimal point lines The logic states of the data on these lines is determined by the setting of the Model 160B Range Switch The Range Switch setting should not be changed while the Digital Output is in a Hold mode 6 Display Hold This Hold line affects the Model 160B LSI circuit directly When this Hold is applied the numerical data present at the Model 1608 display and at the Digital Output is not up dated as conversions are completed The Display Hold line is activated by a logic 0 When Dis play Hold is returned to logic 1 numerical data at the display and Digital Output will be updated normally The Display Hold is not synchronized with a par ticular point in the conversion cycle If the Display Hold is activated during the t me that the Flag is normally low numerical data from either the most recent conversion or the conver sion previous to it may be retained A similar situation can occur if the Display Hold is re leased during the time when Flag is normally low The Display Hold should be activated after Flag has gone from low to h gh the Display Hold should
91. range AS A DC AMMETER MAXIMUM ACCURACY RANGE READING t ot rdg of rng 10 nA 19 99 nA 03 02 100 nA 1999 02 01 1999 u A 0 2 01 10u 1999 u A 02 01 100 A 199 9 u A 02 01 1 mA 1999 mA 02 01 10 mA 19 99 mA 02 01 100 mA 199 9 mA 03 01 1000 1999 03 01 Internally fused beyond 3 amperes SHUNT TEMPERATURE COEFFICIENT ALLOWABLE RESISTANCE r ot rdg of 9 INPUT 1 MI 002 0 02 225 100 kt 002 001 25 mA 10 002 901 1 kf 001 001 3 4 100 001 90 4 A 10 a 001 9014 1 u 00 001 1 01 wu 001 001 3 01 t 001 0 01 Set healing due to long term measurament of greater than 1 ampere can cause 313 NORMAL MODE REJECTION RATIO Greater than 60 dB above one digit for a current of line frequency or twice line frequency AS AN OHMMETER VOLTAGE ACROSS MAX ALLOWABLE MAXIMUM ACCURACY UNKNOWN TEMPERATURE COEFFICIENT INPUT RANGE READING t of rdg of rng at tull range t ol rdg of rng C rms dc 1f 1999 1 0 4 01 1 004 003 250 v 1999 1 03 01 10 004 001 250 100 1999 Q 03 01 100 004 801 250 v 1 1999 03 01 100 004 001 250 v 10 1999 03 01 100 0 04 01 01 250 V 100 198 9 KN 03 01 100 004 001 250 V 1 Mf 1399 0 3 01 100 004 991 250 V 19 99 0 03 0
92. rol is convenient when making measurements on the lmV Range A test set up and cables when connected to the 160B may cause offset voltages because of thermoelectric effects See Section 3 9 These offset voltages might be only a few microvolts or several tens of microvolts In such situations the Zero control can be used to buck out any initial offsets Low thermal cabling and connections should be used when ever possible The instrument zero can also be check ed and adjusted by shorting the input on any range voltage current or resistance The Zero control will have varying effects on the different ranges depending on the sensitivity of the input amplifier but the zero control can be used in this manner Again it should be emphasized that for most meas urements with the Model 160B the Zero control can be set once and then left untouched See also Sec tion 3 6c Low Ohms Zeroing NOTE With the input open on the ImV Range the Model 160B display may show a reading as high 100 This is equivalent to an offset current of 10 0pA If the display shows a reading greater than 100 then the internal potentiometer R121 should be readjusted Typically the offset cur rent will be less than 5 e Row to Use Model 1601 AC DC Probe make Measurements connect the Model 1601 accessory AC DC Probe to the Model 160B input terminals Set the Range to desired voltage range Set switch on probe to Use the
93. s Grouped by Function 25 STROBE 1 STROBE 4 36 1 x 10 1 x 103 OVERRANGE 17 2 x 109 11 OVERLOAD 35 4 x 10 29 i POLARITY 16 8 x 10 c H yum 5 spe Sates 6 i STROBE 5 5 STROBE 2 10 FLAG 34 1 x 10 28 FLA 15 2 x 101 22 FLAG RESET 33 4 x 101 a 14 8 x 101 4 STROBE 6 fe ee ep 9 i 1 1 000 24 STROBE 3 27 i DP 2 10 00 32 1 x 102 8 DP 3 100 0 2x 102 c pect en 4 x 102 BCD HOLD 8 x 102 DISPLAY HOLD EXT VOLTS LO in parallel with some of the BCD digit outputs the BCD digits will be unaffected provided lines 26 and 4 set to logic 1 At another time lines 25 5 and 24 may be set to logic 1 and lines 26 and 4 to logic 0 This will present the DP overload polarity and 1 x 10 outputs to the same 16 bit register b When a particular 1608 16028 is being op erated line 6 may be set to logic 0 enabling FLAG and FLAG When the data from this particu lar 1608 16028 is not of interest line 6 may be set to logic 1 which disables FLAG and FLAG Then another device may use the same line for interrupt or polling c Since the data is in 4 bit or smaller groups all output data from the 1602B may be sequentially connected to a 4 bit bus using the same technique described above This is useful when interfacing to programmable calculators and logic systems where bit parallel character ser ial data transmission
94. s 10M9 0 02 10 00M2 t4 digits 3 Adjust front panel Zero Control R114 as 100M9 40 5 100 0MQ 101 digits 2 2 necessary to achieve 000 display 1000M2 1000 301 digits 4 Remove short See Specifications for temperature coefficient for resistance 5 Apply dc voltage to input of Model 160B as given in Table 6 3 and select appropriate range e Current Accuracy Check 6 For each voltage range verify that the Model l Fuse Check 1608 reading is within the tolerance stated a Select 1000mA range d Resistance Accuracy Check b Measure resistance between input terminals l Select the 12 range using ohmmeter F 2 Connect Res stance Source E to input and c Verify that resistance is less than 1 ohm adjust Model 1608 zero for a 3 0000 reading d An open circuit condition indicates that 3 Verify that the Model 160B reading is within the current protection fuse is either not instal the tolerance stated in Table 6 4 for 12 100 and led or is blown Replace fuse F101 on pc board 1002 ranges PC 349 as necessary 4 With Resistance Source E connected and set to 00 select the lmV range and adjust the Model 1608 zero for a 000mV reading TABLE 6 3 Accuracy Check for DC Voltage Source B Divider C Over all Display Tolerance Input Setting Range Accuracy Reading on Reading 1 000000 V 0 001 1 mV 0 032 1 000 2 digits 1 000000 0 01 10 mV 0 015 10 00 digits 10 00000
95. s at rear of instrument to see if they are Q 56uF filter capacitor set correctly Measure the voltage at TP202 with respect to Input Lo The voltage should be 5V 2 Display Zero and Rectifier Zero Adjustment 5 in the LINE mode of operation and also in the and BAT modes of operation if batteries a Select 100mV Range on Model 1608 are installed b Connect Voltage Source J to Divider K 2 12V Regulated Supply Check the Line Volt age Switches at rear of instrument to see if they Set Voltage Source J for 1V and set are set correctly Measure the voltage at TP201 Divider K for 0 001 ratio with respect to Input Lo The voltage should be 12V 5 in the LINE mode of operation and also d Apply a lmV signal to the Model 1608 input in the and BAT modes of operation if bat teries are installed e Adjust Display Zero R136 for a reading of 01 0 at the Model 160B display 3 Battery Check See Section 6 3 f Apply a lmV signal c How To Calibrate the Instrument For best ac curacy the Model 1608 should be calibrated with the g Adjust Rectifier Zero R135 for a reading Model 1609 Cal Cover Accessory or an equivalent of 01 0 at the Model 160B display The instrument should be allowed to stabilize for approximately 1 2 hour after the Cal Cover is put NOTE in place It is important that the calibration se quence be followed exactly because the adjustments It may be ne
96. strument 22 e Rotate handle of Instrument so that handle 18 toward rear of Instrument Handle can be removed completely if desired by separating top and bottom covers f Remove two Slotted Screws 1 1 4 in long used to hold top and bottom covers together near front feet g Position Instrument so that holes in bottom of Instrument align with two front holes on Support Plate h Using two Slotted Screws Item 5 and two Flat Washers Item 6 secure Instrument to Support Plate Tighten screws only enough to prevent lateral movement Do not over tighten screws since damage to plastic feet could occur 0875 MODEL 160B THEORY OF OPERATION SECTION 4 THEORY OF OPERATION 4 1 GENERAL This section contains information to range level See Table 4 1 signal flow path describe the Model 160B circuit operation The cir be described as follows An input signal applied cuits are arranged on a single mother board to faci at the Input HI terminal is attenuated by a resistor litate troubleshooting and servicing divider The signal is filtered and applied to a modulator circuit The ac signal is then amplified a The basic digital voltmeter consists of two and demodulated final high gain dc amplifier pro sections packaged together in one chassis 1 ana vides dc signal for the Analog Output and to 2 log amplifier with shunt resistors for current meas converter resistor divider feeds back a portion ureme
97. tage is equal to the input voltage of the analog amplifier to a high degree of accuracy the follow ing relations hold 26 MODEL 160 V Vref Vfb Vref Vin 100 Vin 100 mV Vin out amp Hence the output voltage of the differential ampli fier is equal to the input voltage whatever that be plus a positive voltage of 100mV This 100mV and a series resistor set up a fixed refer ence current 3 Current Setting Resistors Table 4 3 lists the Model 160B Resistance Ranges the series resis tors the currents which are set up and the analog amplifier sensitivity at full range TABLE 4 3 Summary of Resistance Ranges Series Amplifier Range Resistor Current Sensitivity 100 1 mA i mV 10 100 2 1 mA 10 mV 100 100 0 l mA 100 mV 1 1 100 uA 100 mV 10 10 10 uA 100 mV 100 100 1 uA 100 mV 1 MR 1 Mg 100 nA 100 10 M 10 MQ 10 100 100 M 100 l nA 100 mV 100 100 mV 4 Overload Protection load voltage up to 250 VDC is applied to the Model 1608 input terminals CR10l is reverse biased and When a positive over prevents damage to IC amplifier 0101 Current flow from the 250 VDC source is through a current set ting resistor R102 R102 has a value of 499k which prevents excessive currents in the low value current setting resistors When a negative over load voltage up to 250 VDC is applied to the input
98. te o o o o gt 2 4 4 aie d sore Bhia SPO 58 gt 5 5 T gt l 22 to 08 0 4 gt s bs 5 2 9 Tienes gt WAGONS SNONLYNSIS3C SNO 1YNSIS3G o o i 338 Q3SnNn 32N34333H 153 0 2 o o x e o st i uo oe 17 Val oF 8 lt 4 o 02 WINE 1v 23606138 WNO ll e ghd lt Wel oo 9 NOILISOd AD NI S3HOLIMS Oi 5 o o Vi o G21D3NNO gt oe 2 4 i 000 SH3HAnN JAYS ALIA SHONA lt 919 ae t 2 E vaoa 701 AlddMS 531030 4 s 2 9 lt 2 lt gt 2 gt 9 70 37 N33u9 0305 310830 5 4 i 5 o lt lt gt a vw o NOLO 3 32012 5310930 9 Gt ilo d 79 53109 s i E gt 2 9 85 28 gt 9 5 i so IOdiNOD VBNVe uvis S310N00 2 9 Y oe o gore la gt yo IOMINOD INCes S310N30 o 2 1 a y Savavsodi 47 ISME IHO Civ 95310 S a gt r bo 5 s zoia B FOIT SQOvuvJOS2I NI Bev SINIYA HOLY NY 2 3 9592 4 x lOt s w S sm 3SWs3H12 CIV MYC 335 5 7 gt gt x T Ou
99. te position Two positions are d rect reading in nanoamperes nA three positions are direct reading in microamperes uA four positions are direct read ing in milliamperes mA Decimal point is selected by range switch Polarity is automatically displayed If the nput signal exceeds twice full range the d s play blanks to indicate an overrange condition TABLE 3 4 Current Ranges Displayed Units Shunt R Internal wiring resistance can add approx 0 19 to all values of shunt resistance For example on the 1000mA Range the total resistance between the HI and LO input terminals of the Model 160B could be approx 0 28 1174 b How to Determine Accuracy The accuracy of the Model 160B is specified in terms of a percent of read ing and a percent of range For example a display of 1 000 milliampere mA will have an uncertainty of 0 003mA additional reading error should be con sidered if the source resistance is not greater than 1000 times the shunt resistor For example on the lmA range a source resistance of 1000 ohms would re sult in a loading error of approximately 1 of read ing Loading error for other source resistances can be determined by the following relationship 100 x Shunt Resistance 2 error Shunt Resistance Source Resistance How to Determine Maximum Allowable Input the 10 and 100 ranges the maximum input is 250 volts On and higher ranges the Model 1
100. terminals 0101 is biased to limit the current to approximately 2mA Maximum current possible from 0101 and R102 at 250 VDC is approximately 2 5mA which is low enough to protect the low value current setting resistors Q106 has a normal diode drop for positive overloads and an approximate 6V zener drop for negative overloads It protects the input of U101 4 3 ANALOG TO DIGITAL CONVERTER The analog to digital converter includes the following circuits an absolute value circuit a polarity detector an integrator and threshold detector an LSI circuit a clock an LED display and display drive circuitry Absolute value Circuit This circuit produces a positive DC output voltage regardless of the polar ity of the input voltage The relationship is defined by Your k where k 1 1174 MODEL 160B THEORY OF OPERATION R162A R134 ANALOG SIGNAL R162H B FULL RANGE R162F G FIGURE 25 Actual operation is as follows A positive dc voltage at pin 12 of R162 produces an equal dc voltage at the output of U107 and also causes the output of U106 to go negative When this happens 105 is reverse biased and U107 is effectively isolated from the ac tion of 0106 A negative dc voltage at pin 12 of R162 causes the output of U106 to go positive the output of 0106 must go sufficiently positive to forward bias CR105 and drive the input of 0107 In this situation U107 and U106 together function as
101. thstand 250 volt overloads TABLE 4 2 Summary of Current Sensitivity Shunt Amplif er Amplifier Range Resistance Gain Sensitivity 10 nA 1 X100 10 mV 100 nA X100 10 mV l uA Q X100 10 mV 10 X100 10 mV 100 uA X100 10 mV 1 mA X100 10 10 mA 100 10 mV 100 mA 5 100 10 mA E 50 X10 100 mV c Ohmmeter Circuitry This circuitry provides number of fixed currents by using a stable voltage re ference a differential voltage amplifier and a ser ies resistor The circuit is also protected against voltage overloads of 250 volts at the Model 160B put terminals 1 Voltage Reference An adjustable divider made up of resistors R105 R106 and R107 provides an output of approximately l00mV from a stable zener reference 101 This divider is connected to the inverting input of the differential voltage ampli fier The divider is actually adjusted so that the amplifier output is an accurate 100mV when the in put terminals of the Model 160B are shorted 2 Differential Voltage Amplifier This ampli fier circuit includes 0101 resistors R102 R104 R108 R109 R110 and protection circuitry resistors and IC op amp are connected as a unity gain differential amplifier resistor R110 adjusts the gain accuracy The inverting input of the cir cuit is connected to a reference voltage The non inverting input is connected to the feedback volt age of the analog amplifier Because the feedback vol
102. tput is high regardless of the sig nal at the other input By this action the T line signals are prevented from enabling the Digital Uut put latches Once the BCD Hold is activated after the Flag line has gone high the data from the most recent conversion can be retained the Digital Out put latches indefinitely until the BCD Hold is re leased See also Section 3 15 3 BCD Hold h Display Hold Display Hold is activated by a logic 0 at pin 3 of the 37 pin Digital Output con nector J302 NAND gate U320 D inverts the sense of the control signal This inverted signal then goes to the LSI circuit in the Model 160B where it prevents the LSI circuit latches from being updated The numerical data at the Model 160B display and at the Digital Output will remain unchanged as long s the correct control signal level logic 0 is pre sent See also Section 3 15f Display Hold ACCESSORIES MODEL 160 SECTION 5 ACCESSORIES QOO d MODEL 1601 AC DC PROBE GENERAL The Model 1601 is a combination ac de probe MECHANICAL PARTS LIST that enables the user to measure voltages from 45 Hz Item Keithley to 45kHz when used with the Model 160B The slide No Description Part No switch S101 can be used to select either AC mode or straight through DC Mode L Tip 24654B 2 Body Front 24656C SPECIFICATIONS 3 Body Rear 24655C 4 Strain Relief 18676B DC Mode Straight through probe does not alter any 5 Cable
103. uits make up the heart of the analop to digital conversion process The actual conversion technique is based on a charge balancing principle A block diagram of the basic converter action is shown in Figure 27 A positive voltage at 1 1 causes the output of amplifier U109 to go negative the rate of change of this output is a function of the input voltage resistors R161A B and capacitor C120 The negative going output of 0109 causes the threshold detector amplifier UL10 output to change to a posi tive level positive level represents a I at the J input of the J K flip flop the K input is a 0 due to the inverter The charge and discharge periods for the integrator are determined by the state of the Q output of the J K flip flop When the Q output is high diode U108A is reverse biased and the integra tor can only be charged by a voltage from the Abso lute value Circuit When the Q output is low diode U108A is forward biased and discharge of the inte grator occurs Because Q and Q states can be changed only when a clock pulse is present the charge and discharge periods are also a function of the clock frequency The overall a to d converter operates in a free running manner but the timing period for a conversion is set at 2016 counts he reading at the display is derived by counting the number of clock pulses in all the discharge periods during a span of 2016 clock pulses This selective counting is easily accomplishe
104. was selected to give a noise bandwidth of approx 0 5 Hz to the overall amplifier when it is used at a closed loop gain of 1000 The integrated circuit 0105 must be X1000 volt X100 1 volt X10 1 volt X100 1 volt X10 1 volt X100 l volt 1 10 volt ble of driving the feedback network RI60A B C and D the A to D converter and the Analog Output to t2 VDC 8 Modulator Demodulator Drive Circuit CMOS inverters U103A and U103B provide opposite phase square waves used to drive MOS FET modulator tran sistors Q102A and Q102B Inverter U103B also pro vides a drive signal for demodulator JFET Q103 Resistors R121 R122 and R123 and capacitors C108 and C109 affect the rise and fall times of the square wave drive signals R121 adjusts the rise and fall time of 0102 only so that the total charge both positive and negative transferred to the input can be minimized Any net charge at the input creates a current which in the Model 1608 is specified to be less than 10 The frequency of the drive signal is determined by the clock cir cuit and LSI U201 Circuitry in LSI U201 divides down a nominal clock frequency of 9680 Hz to pro duce 220 Hz 9 Offset Current Zero Circuit See Section 4 2 8 10 Front Panel Zero voltages across po tentiometer R114 are set up by a stable zener re ference diode VR101 and an IC op amp 0102 These voltages are approximately 2 VDC which give R114 an adjustme
105. y Description 1 RF PROBE Specifications 1 STRAIGHT TIP Transfer Accuracy 57 100kHz to 100MHz 20 C i HOOK TIP 30 C useable lkHz to 1GHz peak responding cal 1 GROUND CLIP ibrated in rms of a sine wave 1 ADAPTER Input Impedance 4 megohms shunted by 2 picofarads 1 BANANA PLUG ADAPTER Not used with Model 1608 Max Allowable Input 30V rms ac 200 dc 1 12 2 RESISTOR STRAIGHT TIF GROUND CLIP ATTACHES HERE HF ADAPTER DUAL BANANA PLUG HI 10 MODEL 1682 RF PROBE 34 1277 MODEL 160B SECTION 6 6 1 GENERAL This section contains information essary to maintain the instrument Included are pro cedures for electrical Performance Checks Calibration Troubleshooting and Battery Replacement and Charging 6 2 REQUIRED TEST EQUIPMENT Recommended test equip ment for checking and maintaining the instrument is given in Table 6 1 Test equipment other than recom mended may be substituted if specifications equal or exceed the stated characteristics 6 3 PERFORMANCE VERIFICATION Use the following pro cedures to verify basic operation of the instrument All measurements should be made at ambient temperature of approximately 25 C and relative humidity below 50 If the nstrument is out of specification at any point perform a complete calibration as given in Section 6 4 For each function that is checked an additional un certainty due to temperature coefficient should be considered if the am

Keithley -- 160B - subfrequenz.net

Contents

Download Pdf Manuals

Related Search

Related Contents