Home

HP 419A User's Manual

1. A4C6 A4C7 0180 0224 fxd Al elect 10 uF 75 10 15 vdew 56289 30D106G015 BA4 A4C8 0180 0061 fxd elect 100 uF 100 10 15 56289 30D107G015 DD4 4 9 0160 0859 C fxd my die 1 0 uF 10 50 56289 148 4 10 0180 0100 fxd Ta die 4 7 10 35 56289 1500415 9035 2 4 11 0180 0155 fxd elect 2 2 uF 20 20 56289 1500225 0020 4 12 0180 0061 fxd elect 100 pF 100 10 15 56289 30D107G015 DD4 A4C13 0160 0932 fxd my die 4 uF 20 30 56289 148P A4C14 A4C15 0180 0228 fxd Ta elect 22 uF 10 15 56289 1500226 9015 B2 DYS A4C16 0180 0393 fxd Ta elect 39 uF 10 10 96289 1500896 9010 B2 DYS A4C17 0180 0228 fxd Ta elect 22 10 15 56289 1500226 9015 B2 DYS A4CRI1 thru 1901 0025 Diode 100 mA at 1 V 100 piV 12 pF 93332 D3072 A4CRI16 A4Q1 A4Q2 1854 0226 Transistor NPN Si 96289 TN 56 403 1854 0033 Transistor NPN Si 253391 24446 2N3391 A4Q4 1853 0010 Transistor PNP Si 04713 SM4713 A4Q5 1854 0033 Transistor NPN Si 2N3391 24446 2N3391 A4Q6 1853 0010 Transistor PNP Si 04713 SM4713 A4Q7 thru 1854 0033 Transistor NPN Si 2N3391 24446 2N3391 A4Q10 A4Q11 1853 0010 Transistor PNP Si 04713 SM4713 A4Q12 1854 0033 Transistor NPN Si 2N3391 24446 2N3391 A4Q13 1853 0010
2. 22 MOOK SIRI9 3M o 0000000000 a ASRS OT E SCHEMATIC APPLIES TO SERIALS PREFD HP 419A DC Null Voltmeter max Model 419A e EEE eee eee ee eee ns oe gt Appendix C BAT TEST 12V 13v ta 526 IOOHF 35 5 CRIO i9 CRH CRI2 bcm J5 2 Ltj S2RI se HE 23 2 7K WOKS TIT 18 R El 20K 47 co LES 5 iF R47 B S 5 i3 Sr pal of 7 4 ie agg Gn mes A va 2 ps 5518 RANGE SIACF IOAN 51415 140 2 5 SIRI4 i foo 40K 3 c 4 W 20K SIRIG E LA S 5 SIRIT i 4K 6 8 OQ R44 9 iv j 5 TOK 10 R25 IK av z l V i 15 Wl es le p eee 4 Y yy d anne 13V 43V l N SCHEMATIC APPLIES SERIALS PREFIXED 54 532 AND 646 ONLY Figure C 2 Amplifier and Amplifier Switching 01779 2 HP 419A Null Voltmeter max Schematic and Component Location Diagrams Serial Prefixed 514 532 646 C 3 C 4 Model 419A Appehdix IE eee d H gt 52 95 2 OR 2 Cw J Lu e gt IT e lt Q gt oe fo 3 g oj oj io t
3. Erie C W Marwedel San Francisco Calif Micamokd Electronic Mfg Corp Brooklyn N Y James Millen Co Inc Malden Mass J W Miller Los Angeles Calif Monadnock Mills San Leandro Calif Mueller Electric Co Cleveland Ohio Oak Manufacturing Co Crystal Lake Bendix Pacific Division af Bendis Corp Pacific Metals Phaostran instrument and Electronic Co Phoell Mfg Co Philadelphia Steel and Wire Corp Philadelphia Pa Potter and Brumfield Div of American Machine and Foundry Princeton ind Radio Condenser Co Camden N J Radio Receptor Co Inc Brooklyn N Y Resistance Products Harrisburg Pa Rubbercraft Corp of Calif Torrance Calif Shakeproof Division of Tool Works Signal Indicator Carp Siruthers Diamn lac Thompson Bremer amp Co Tilley Mfg Stackpole Carbon Standard Thomson Corp Tinnerman Products Inc Transformer Engineers Ucinite Co Veeder Root Inc Wenco Co Continenlal Wirt Electronics Corp Philadelphia Pa New Rochelle No Hollywood Calif Francisco Calif South Pasadena Galii Chicago 111 Elgin 1 New York N Y Pitman N J Chicago lil San Francisco Calif St Marys Waltham Mass Cleveland Ohio Pasadena Calif Newtonville Mass Hartford Conn Chicago 111 Zierick Mfg Carp Division af Sessions Clock Co Morristown N J Schnitzer Al
4. Oo 06 Dob b oO DENOTES MAIN SIGNAL PATH 8 X AVERAGE VALUE SHOWN OPTIMUM VALUE SELECTED DENOTES DC FEEDBACK PATH FACTORY SEE PARAGRAPH 5 51 FOR REPLACEMENT INSTRUCTIONS DENOTES AC FEEDBACK PATH 9 DENOTES TWISTED PAIR 5 DENOTES FRONT PANEL MARKING 10 VOLTAGES INDICATED IN RED ARE MEASURED WITH VM DENOTES REAR PANEL MARKING PUSHBUTTON DEPRESSED 1 V RANGE INPUT SHORTED ALL VOLTAGES ARE 10 6 m DENOTES SCREWDRIVER ADJUST SIR26 pare MODULATOR E 8 SIDIR P O S2 52 SIDI SIERO SIE F 867 4ll 3 LU g A NE C S 2 C C O m d gt Cog THEE 2 40 9 9 M gt Y 0 CR3 OJ 220K 5 KO 5 t 51932 c2 C3 v2 e is D EO D X AC D 125 a OA 9 AO 5 NE 185 7 ene i i i i 99 o 1 2 2 9 95 4 186 PHOTO CHOPPER ASSEMBLY D 390K D gt lt 47 AG D 00419 63001 4 91824 Qum uu 2 9 KO 9 2906 96 SiR8 e 39K 9 KO X9 OF SIR9 SIR25 12K 59 9 06M 9 SIRIO R6 33002 2200 1 a R3 NULL EA COARSE 300 MAX FINE KE 90M 59 R4 e 42 M 22 31923 2 E e 29 29 AUC 5 9 Jo S S R22 2 9 AC an DA DA X AD 2 un SIR2I
5. Nahm Bros Spring Co Oakland Calif Tru Connector Corp Peabody Mass Universal Metal Prod Inc Bassett Puente Calif Elgeel Optical Co Inc Rochester N Y Tinsolite Insulated Wire Co Tarrytown N Y Sylvania Electric Prod Inc Semiconductor Div Robbins and Myers lac Stevens Mfg Co Inc Howard J Smith Inc Bearing Engineering Co Connor Spring Mfg Co Mitler Dial amp Namentate Radio Materials Co Augat Brothers Inc Date Electronics Inc Elco Corp Woburn Mass New York N Y Mansfield Ohio Port Monmouth J 00015 39 Revised February 1965 Cade Ho 93923 93982 9413 94144 94145 54148 54184 54197 94222 94310 94330 94682 95023 35236 95238 95253 55264 95265 95275 95348 55354 85712 5987 96067 96095 96256 96296 96330 96341 96501 97464 97539 97966 57979 38141 98159 CODE LIST MANUFACTURERS Sheet 2 of 2 Manufacturer Address Controls Livingston N J Insuliae Van Norman lad inc Electronic Division Manchester N H General Cable Corp Bayonne N J Raytheon Mfg Co Industrial Components Div Receiving Tube Operation Quiacy Mass Raytheon Mfg Co Semiconductor Div California Street Plant Newton Mass Scientific Radio Products Inc Loveland Colo Tung So Electric lnc Newark Curtiss Wright Corp Electronics Div East Paterson Souihco Div of 5 Chester Corp Lester
6. voltmeter mode the input voltageis applied to the Input Attenuator through the and INPUT terminals and through 51826 Inthe null volt metermode the inputis applied in thesame manner butis opposedby thebucking voltageappliedto S1R26 4 14 When the SET NULL Pushbutton is depressed the 5 voltage is applied through R4 and 5 and the voltage divider network S1R1 thru S1R11 to S1R26 The difference between the input voltage and the bucking voltage is indicated on the Meter M1 The bucking voltage is then adjusted through the use of course and fine NULL controls R4 and R5 untila nullis indicated on the Meter When the READ NULL Pushbutton is depressed the input voltage is disconnected and the polarity of the bucking voltage is reversed The value of the bucking voltage equal to input voltage is indi cated on the Meter M1 4 15 INPUT ATTENUATOR 4 16 All voltages and currents to be measured are applied to the input attenuator which is a resistive divider consisting of S1R20 to S1R25 and R3 The attenuation factor depends upon the position of the RANGE switch The attenuator is divided into two separate networks to provide the proper impedance levels for filter capacitors A3C2 and A3C3 Table 4 1 lists the attenuation factors for all ranges 4 17 INPUT FILTER 4 18 L1 and L2 and A3C2 and A3C3 filter superim posed noise from the input signal 4 19 MODULATOR DEMODULATOR 4 20 The modulator demodula
7. The output of the stable voltage source or the power supply is adjusted until the Model 419A indicates null The voltage range used onthe Model 419A depends on how much drift is anticipated from the power supply Ifthe power supply output drifts 8mV over a period of time the Model 419Awillindicate this variation onthe 10mV range and supply the strip chart recorder with a voltage that changes from 0to 0 8 Vover the same period Inthiscase the drift is amplified by a factor of 100 Gains as high as 333 000 on the 3 uV range are available when the Model 419A is used on the lower ranges 01779 2 HP 419A DC Null Voltmeter max Model 419A Section IV A pl ia t6 d r Y 1315 cy Word IPPON JO8 1NOO 430V8QO 334 15 O d HOLV INGOW ag V O d YOLV INGOW V O d 0H v6lIb LAdNI YOLVANALLY LONI 1 O d 92415 az HP 419A DC Null Voltmeter max AlddNS ONIXOn8 IS O d QNV slg 01779 2 4 0 419 Section IV SECTION IV THEORY OF OPERATION 4 1 INTRODUCTION 4 2 This section contains the theory of operation of the Model 419A DC Null Voltmeter 4 3 GENERAL DESCRIPTION 4 4 The Model 419A functions as a dc voltmeter null voltmeter and a dcammeter When usedasa de voltmeter the Model 419A provides end scale ranges from 3 LV to 1000 V with an input r
8. e oer 59 gt ral O E NDS I 16 uy m gt o 556 gt 2s Figure 4 A2 Board Ser ials Prefixed 514 Oh Pw j A 4 Figure 3 Neon Driver Serials Prefixed 514 01779 2 5 HP 419A Null Voltmeter max
9. Carad Corp Redwood City Calif General Mills Minneapolis Mina North Hilis Electric Co Clevile Transistor Prod Div of Clevite Corp International Electronic Research Corp Columbia Technical Corp Varian Associates Marshall Industries Electron Products Division Pasadena Calif Control Switch Division Controls Co of America EI Segundo Calif Delevan Electronics Corp Fast Aurora N Y Wilco Corporation Indianapolis Ind Renbrandt Inc Boston Mass Hoffman Semiconductor Div of Hoffman Electronics Corp Technology Instrument Corp of Calif Mineola R Y Waltham Mass Burbank Calif New York N Y Pato Alto Calif Evanston ill Newbury Park Calif THE FOLLOWING VENDORS HAVE NO NUM BER ASSIGNED IN THE LATEST SUPPLEMENT TO THE FEDERAL SUPPLY CODE FOR MANUFAC TURERS HANDBOOR 10000 0000 0000M 0000 00002 DOOAA 000 000 0008 000 QOONN 00069 00055 000 0 S K Smith From Winchester Electronies Inc Santa Monica Calif Maico Tool and Die Los Angeles Calif Western Coil Div of Automatic Ind inc Redwood City Calif Mig Inc Holliston Mass Willow Leather Products Corp Newark N J British Radio Electronics Ltd Washington D C ETA England Indiana General Corp Elect Div Indiana Precision Instrument Components Co Van Nuys Calif Hayward Calif San Jose 27 Calif Oakland Calif Burbank Calif Burlinga
10. Diode network CR5 to CR12 protects the amplifier circuit from an overload 4 30 METER CIRCUIT 4 831 The meter is a current driven device which utilizes taut band movement 1 volt output of the dc amplifier provides end scale needle deflection on allranges During FAST CHARGE and off positions 1 and 2 of Function Switch 82 the meteris protected from transient voltages by a short across it During the BATTERY TEST mode position 3 of Function Switch S2 resistor S2R1 providesthe amplifier load because the meter is disconnected from theamplifier circuit 4 32 Resistors R41 to R44 provide for calibration of the meter The resistors are connected in parallel with the meter as a function of the RANGE switch setting 4 33 FEEDBACK CONTROL 4 34 Control of feedback is accomplished through a deck of the RANGE switch The amount of feedback depends upon the position of the RANGE switch The closed loop gain of the amplifier may be determined by subtracting the feedback from the forward gain The feedback provided for each range is listed in Table 4 1 01779 2 HP 419A DC Null Voltmeter max Model 419A 4 35 POWER SUPPLY AND NEON DRIVER Figure 6 4 4 36 The power sourcefor the 419A isfour recharge ablebatteries which supply a 13 V anda 13 V output The 419A may also be operated from line voltage which will trickle charge the batteries during operation 4 37 Theline input may be either 115 V or 230 V
11. Hewlett Packard Canada Ltd 1762 Carling Avenue 613 722 4223 TWX 610 562 1952 Toronto Oniario Hewlett Packard Canada Ltd 1415 Lawrence Avenue West 416 249 9196 TWX 610 492 2382 Vancouver B C Hewlett Packard Canada Ltd 2184 W Broadway 604 738 7520 TWX 610 922 5059 Appendix Model 419 SALES AND SERVICE OFFICES ARGENTINA Mauricio A Suarez Telecommunicaciones Carlos Calvo 224 Buenos Aires Tel 30 6312 34 9087 AUSTRALIA Sample Electronics Vic Pty Ltd 9 1 Cremorne Street Richmond 1 Victoria Tel 42 4757 Sample Electronics N S W Pty Lid 4 Grose Street Giebe New South Wales Tel 69 6338 AUSTRIA Unilabor H m b H Wissenschaftfiche Instrumente Rummelhardigasse 6 3 Box 33 Vienna IX 71 Tel 426 181 BELGIUM Hewlett Packard Benelux S A 20 24 rue de Y Hopital Brussels Tel 11 22 20 BRAZIL Ciental Importacao e Comercio Ltda Rua des Eliseu Guilherme 62 Sao 8 Tel 70 2318 CHILE Hector Calcagni Casilla 13942 Santiago Tel 6 42 26 DENMARK Tage Olsen A S Ronnegade 1 Copenhagen 0 Tel 29 48 00 FINLAND INTO 0 Meritullinkatu 11 Box 153 Helsinki Tel 6 1133 FRANCE Hewlett Packard France 150 Boulevard Massena Paris 13 Tel 707 97 19 Hewlett Packard France 2 tue Tete d Or Lyon 6 Rhone Tel 52 35 66 GERMANY Hewlett Packard Vertriebs GmbH Kurhessenstrasse 95 Frankfurt a Main Tel 52 00 36 Hewlett Packar
12. Tel 3 3817 F H Flanter amp Co Pty Ltd Box 200 Bramley 715 Pretoria Main Road Wynberg Transvaal Tel 40 6871 SWEDEN HP Instrument AB Centralvagen 28 Solna Centrum Tet 08 83 08 30 HP Instrument AB Box 4028 Indunagatan 28A Mo ndal 4 Tel 27 68 00 SWITZERLAND Max Paul Frey Wankdorffeldstrasse 66 Berne Tel 031 42 00 78 TAIWAN Hwa Sheng Electronic Co Ltd 0 Box 1558 21 Nanking West Road Taipei Tel 46076 45936 TURKEY Telekom Engineering Bureau 0 Box 376 Galata Istanbul Tel 49 40 40 UNITED KINGDOM Hewlett Packard Ltd Dallas Road Bedford England Tel 68052 VENEZUELA Citec Edif Arisan Of 4 Avda Francisco de Miranda Chacaito Caracas Tel 71 88 05 YUGOSLAVIA Betram S A 83 Avenue des Mimosas Brussels 15 Belgium Tel 35 29 58 Sales and Service Assistance in Areas Not Listed Contact EUROPE Hewlett Packard S A 54 Route des Acacias Geneva Switzerland Tet 022 42 81 50 ELSEWHERE Hewlett Packard 1501 Page Mill Road Palo Alto California 94304 U S A Tel 415 326 7000 5 66 Model 419A Appendix MANUAL BACKDATING CHANGES MODEL 419A R DC NULL VOLTMETER Manual Serial Prefixed 707 hp Part No 00419 90002 This manual backdating sheet makes this manual applicable to earlier instru ments Instrument component values that differ from those in the manual yet are not listed in the backdat
13. on uV range is longer than 3 seconds the value of A4R26 should be decreased re sponse on 3 uV range is less than 2 seconds 01779 2 HP 419A DC Null Voltmeter max Model 419A A4R26 should be increased A4R26 should be between 6 8 kQ and 15 kQ with a typical value of 10 A4R26 is an Allen Bradley com position 1 4 watt 10 resistor Figure 5 4 Neon Drive Waveform A2TP2 5 35 ELECTRICAL ZERO ADJUSTMENT 5 36 The electrical zero adjustment should be per formed when the meter pointer does not indicate zero on the 1 volt range when instrument power hasbeen on forat least oneminute No external equipment is re quired for this adjustment a Set 419A controls as follows RANGE op uu tee Sat tee ei 1V ZERO pushbutton Depressed b Remove top cover adjust A4R14 1 V ZERO for zero deflection on 419A meter 5 37 FULL SCALE CALIBRATION 5 38 Thefull scale calibration consists of performing the 3 uV 10 uV 1 mV and 1 V adjustments Volt meter Calibrator hp Model 738BR 100 2 Resistor hp Part No 0811 0398 and a 1 MQ Resistor hp Part No 0811 0473 are required for this test Connect test setup illustrated in Figure 5 1 b Remove419Atopcover depress VM AMpush button c Set Voltmeter Calibrator for 30 mV output connect 419A to Point A adjust A4R41 3 uV for full scale deflection on 3 uV range d Set Voltmeter Calibrator for 100 mV output co
14. 11250 71232 17342 77630 17638 77764 11959 18185 18283 78290 78452 18471 78488 78493 18553 78790 18947 79142 79251 1972 79963 80031 80120 80130 80131 80207 80223 80248 80294 80411 80486 80509 80583 80640 81030 81973 81095 81312 ave been arbitrarily assigned to suppliers not appearing in the H4 handbooks Monufacturer Address Hughes Products Division ol Hughes Aircraft Co Newport Beach Calif Amperex Electronic Co Div of North American Phillips Co inc Hicksville N Y Beckman Helipot Corp So Pasadena Calif Bradley Semiconductor Corp Hamden Conn Catling Electric Inc Hartford Conn George Garrett Co Inc Philadelphia Pa Federal Screw Chicago ill Fischer Special Mfg Co Cincinnati Ohio The General Industries Elyria Ohio Goshen Stamping amp Toot Co Goshen Ind Electronics Corp Brooklyn Jennings Radio Mig Co San Jose Calif Signalite Inc Neptune N J J H Winns and Sons Winchester Mass Industria Condenser Corp Chicago lll R F Products Division of Amphenol Borg Electronics Corp Danbury Conn E F Johnson Co Waseca Minn International Resistance Co Philadelphia Pa Jones Howard B Division of Cinch Mfg Carp Chicago 111 James Knights Co Sandwich Ul Electric Corporation Mt Vernon N Y Lenz Electric Co Chicago LitHefuse Inc Des Plaines Lord
15. 9 om Hn CO J D O 01779 2 POINT OF MEASUREMENT FIGURE 0 1 419A READING 2 84 to 9 7 to 29 3 to 97 9 to 293 9 to 0 98 to 2 94 to 9 8 to 29 4 to 98 to 294 to 0 98 to 2 94 to 9 8 to 29 4 to 98 to 294 to 280 to 9 1 HP 419A DC Null Voltmeter max Section V Model 419A VOLTMETER CALIBRATOR hp 419A hp 738BR DC NULL VOLTMETER 4l9A B O395 Figure 5 2 Ammeter Accuracy Test Setup 5 11 AMMETER ACCURACY TEST d Start strip chart recorder andturn voltmeter era fe het ee he MV calibrator dc output on if strip chart re corder does not show OUTPUT at 95 between 2and3 seconds perform Chopper Adjustment Paragraph 5 33 5 12 The ammeter accuracy performance test is il lustratedin Figure 5 2 Avoltmeter calibrator hp Model 738BR a 9 MQ resistor hp Part No 0698 5443 anda 900 resistor hp Part No 0698 5488 are required for this test e Turn voltmeter calibrator dc output off and setfor 100 mV output set 419A RANGE switch a Connect test setup illustrated in Figure 5 2 to 10 position b SetModel 419A and voltmeter calibrator con f Start stripchart recorderand turn volimeter trols as indicated in step 1 of Table 5 3 If calibrator dc output on if strip chart re Model 419A reading is not within the listed corder does not show OUTPUT at 95 within tolerances troubleshoot the input attenuator 1 second perform Chopper Adjustment P
16. 914 452 7425 Syracuse 13211 5858 East Molloy Rd 315 454 2486 TWX 710 541 0482 Endicott 13764 1219 Campville Rd 607 754 0050 TWX 510 252 0890 NORTH CAROLINA High Point 27262 1923 N Main Street 919 882 6873 TWX 510 926 1516 OHIO Cleveland 44129 5579 Pearl Road 216 884 9209 TWX 216 888 0715 Dayton 45409 1250 W Dorothy Lane 513 298 0351 TWX 513 944 0090 OKLAHOMA Oklahoma City 405 235 7062 PENNSYLVANIA Camp Hill 717 737 6791 West Conshohocken 19428 144 Elizabeth Street 215 248 1600 and 828 6200 TWX 518 660 8715 Monroeville 15146 Monroe Complex Building 2 Suite 2 Moss Side Bivd 412 271 5227 TWX 710 797 3650 HP 419A DC Null Voltmeter max TEXAS Dallas 75209 Box 7166 3605 Inwood Rd 214 357 1881 TWX 910 861 4081 Houston 77027 Box 22813 4242 Richmond Ave 713 667 2407 TWX 713 571 1353 UTAH Salt Lake City 84115 1482 Major St 801 486 8166 TWX 801 521 2604 VIRGINIA Richmond 23230 2112 Spencer Road 703 282 5451 TWX 710 956 0157 WASHINGTON Bellevue 98004 11656 8th St 206 454 3971 TWX 910 443 2303 GOVERNMENT CONTRACTING OFFICE San Antonio Texas 78226 Hewlett Packard Contract Marketing Division 225 Billy Mitchell Road 512 434 4171 TWX 512 571 0955 CANADA Montreal Quebec Hewlett Packard Canada Ltd 8270 Mayrand Street 514 735 2273 TWX 610 421 3484 Telex 01 2819 Ottawa Ontario
17. Corp No Chicago Il Fafnir Bearing Co New Britain Conn Fed Telephone and Radio Corp Clifton N J General Electric Co Schenectady N Y G E Lamp Division Nela Park Cleveiand Ohio Santa Clara Calif Livingston NJ Spruce P ne N C Lodi J Teterboro N J 00015 39 Revised February 1965 Phoenix Ariz Code No 24655 26365 26462 26992 28480 33173 35434 36196 37942 39543 40920 42190 43990 44655 47904 48620 49556 32080 63743 54294 55026 55933 55938 56137 56289 59446 59730 60741 61775 62119 3143 64953 65092 66295 66346 70276 70309 70313 70485 70563 70303 70958 71002 11041 71218 71286 71313 71400 71436 71450 71468 nal 71482 71590 71616 71700 71744 71253 71785 71984 72092 72136 71707 72354 72613 72556 12549 72158 12765 72825 72928 12964 72982 13061 73076 73138 Manufacturer Address General Radio Co Gries Reproducer Corp Grobet File of America Inc Hamilton Watch Co Hewlett Packard Co Receiving Tube Dept Lectrohm Inc Chicago Stanwyck Corp Hawkesbury Ontario Canada Mallory amp Go Inc indianapolis Ind West Concord Mass New Rachelle N Y Caristadt 2 Lancaster Palo Alto Calif wenshoro Ky Mechanical ndustries Prod Co Akron Ohio Miniature Precision Bearings Inc Keene N H Muter Co Chicago IIl Norpren Co Chmite Mfg Co Po
18. Input a aa r es 3 3 4 2 4 19 Modulator Demodulator 4 2 4 23 AC Amplfiek 3 4 2 4 26 DC Amplifier a 4 2 4 30 M ter Circuiti ooe a wow eee i 4 2 4 33 Feedback 4 2 4 35 Power Supply and Neon Driver Figure 6 4 4 3 Number Page 1 1 Model 419A Specifications 1 0 1 2 Accessory Equipment Supplied 1 1 1 3 Accessory Equipment Available 1 1 4 1 Model 419A Attenuation and Gain Characteristics s ps ace s wo X 4 1 01779 2 Number 9 1 Test Equipment Required 5 2 Accuracy Performance Test Sup plemental Data 5 3 Ammeter Accuracy Test 7 1 Replaceable Parts Replaceable Parts HP 419A DC Null Voltmeter max l OT Ot CI i en cei ds gt pb 6 DDD B2 BO GI 1 oi ES Page 9 0 9 1 5 2 1 2 111 List of Illustrations Model 419A LIST OF ILLUSTRATIONS Number Page 5 4 Neon Drive Waveform A2TP2 5 4 6 1 Model 419A Component Location DLAC PAU ee ee dec 6 2 6 2 Range Switch 51 Component Location BE C cor 6 2 6 3 Amplifier and Amplifier Switching Schematic and Component Location wo ey 40 6 3 6 4 6 4 Power Supply and Neon Driver Number Page 1 1 Model 419A DC Null Voltmeter 1 0 3 1 Front
19. K 10 1 2 W hp Part No 0687 1031 Change AiR40 to fxd 39 10 1 2 W hp Part No 0687 3931 01779 2 CA HP 419A DC Null Voltmeter max Appendix 4 Model 419A MANUAL BACKDATING CHANGES Change Paragraph 5 34 steps d and e as follows d A2R12 CHOPPER CURRENT affects both the chopper frequency and current Adjust A2R12 for waveshape shown in Figure 5 3 with peak amplitude of 140 to 160 mV and frequency of 320 to 340 pps this corresponds to chopper rate of 160 to 170 pps as counter also counts smaller pulses e 1826 should be between 10 and 39 with a typical value of 22 Figure 6 4 Substitute Figure C 3 and C 4 for the ones in Figure 6 4 Table 7 1 Change 201 to hp Part No 1854 0039 Transistor NPN Si 2N3053 Change A2Q2 A2Q3 to hp Part No 1854 0033 Transistor NPN Si 2N2925 Change A2Q4 A2Q5 to hp Part No 1854 0039 Transistor NPN 2N3053 Change A2R1 to hp Part No 0687 5611 fxd comp 560 ohms 10 1 2 w Change 2 2 to hp Part 0687 6811 fxd comp 680 ohms 10 1 2 w Change A2R3 to hp Part 0687 3331 R fxd comp 33 K ohms 10 1 2 w Change A2R4 to hp Part No 0687 3321 fxd comp 3300 ohms 10 1 2 w Change A2R5 to hp Part No 0687 6801 R 510 1 2 w Change A2R6 to hp Part No 0687 2731 10 1 2 w Change A2R to hp Part No 0687 4731 fxd c
20. Osaka City Tel 313 0091 INTERNATIONAL Electronic Equipment Yokogawa Hewlett Packard Ltd 4 3 chome Himeikedori Chigusa ku Nagoya City Tel 751 8545 KOREA American Trading Co Korea Ltd Seoul P O Box 1103 112 35 Sokong Dong Jung ku Seoul Tet 3 7049 3 7613 LEBANON Constantin E Macridis Clemenceau Street Clemenceau Center Beirut Tel 220846 NETHERLANDS Hewlett Packard Benelux N V 23 Burg Roellstraat Amsterdam W Tel 020 13 28 98 NEW ZEALAND Sample Electronics N Z Ltd 8 Matipo Street Onehunga S E 5 Auckland Tel 565 361 NORWAY Morgenstierne amp Co A S Ingeniofirma 6 Wessels Gate Oslo Tel 20 16 35 PAKISTAN Mushko amp Company Ltd Dosman Chambers Victoria Road Karachi 3 West Pakistan Tel 54601 Mushko amp Company Ltd Zirat Chambers 31 Jinnah Avenue Dacca East Pakistan Tel 80058 PANAMA Electronico Balboa S A 0 Box 4929 Panama City Tel 3 0833 PERU Fernando Ezeta B Petit Thouars 4719 Mira Flores Lima Tel 5 0346 PORTUGAL Telectra Rua Rodrigo da Fonseca 103 P O Box 2531 Lisbon 1 Tel 68 60 72 PUERTO RICO san Juan Electronics Inc Ponce Leon No 150 Stop 3 Pta de Tierra Sta San Juan Tel 725 3342 SPAIN Ataio Ingenieros Enrique Laretta 12 Madrid 16 Tel 235 43 44 5 HP 419A DC Null Voltmeter max SOUTH AFRICA Flanter amp Co Pty Ltd Rosella House Buitencingle Street Cape Town
21. Sincethe exact capacity of the Nickel Cadmium batteries cannotbe determinedby voltage measurements it is advisable to charge the batteries before troubleshooting 5 43 NO RESPONSE TO INPUT 5 44 If the meter does not respond to input usually accompanied bya constant offset near full scale after meter has been on for one or two minutes proceed as follows a If one neon is bad all the pulses at 2 2 willbe the same amplitude If the blocking oscillator is bad there willbe no pulses at A2TP2 b Check for approximately 8 volts at the emitter of Q4 to isolate between the blocking oscillator and its voltage regulator c Iftheneon waveform at A2TP2 iscorrect the trouble is in the amplifier 9 5 419A DC Null Voltmeter max Section 5 45 POSITIVE OR NEGATIVE FOLDOVER 5 46 Foldover is whenthe meter needle pegs and then returns on scale when the input is overloaded a positivefoldover occurs check 44012 for low gain b If negative foldover occurs check for low gain in A4Q13 and for a leaky A4C8 or C12 5 47 EXCESSIVE NOISE 5 48 If the 419A meter noise is in excess of 0 3 uV peak to peak proceed as follows a Check the batteries for low charge b Check the chopper frequency in accordance with Paragraph 5 33 Misadjustment of chop frequency or drive a misfiring neon bulb will cause noise c Cleanthe pin connectors on the A4 board with a fiberglass brush ortyp
22. Transistor PNP Si 04713 SM4713 A4RI1 0757 0374 fxd prec met flm 475 1 1 2 W 19701 T O A4R2 0757 0129 fxd prec met flm 178 1 1 2 W 19701 obd A4R3 0687 1241 fxd comp 120 10 1 2 W 01121 1241 A4R4 0687 1041 fxd comp 100 10 1 2 W 01121 1041 A4R5 0687 5601 fxd comp 56 10 1 2 W 01121 5601 A4R6 0687 5621 fxd comp 5600 Q 10 1 2 W 01121 EB5621 A4R7 0687 1211 fxd comp 120 Q 10 1 2 W 01121 1211 A4R8 0757 0374 fxd prec met flm 475 1 1 2 W 19701 A4R9 0687 4751 R fxd comp 4 7 MQ 10 1 2 W 01121 EB4751 A4R10 0687 4721 fxd comp 4700 Q 10 1 2 W 01121 4721 A4R11 0687 2251 fxd comp 2 2 MQ 10 1 2 W 01121 EB2251 A4R12 A4R13 0687 5631 fxd comp 56 10 1 2 W 01121 5631 A4R14 2100 1410 var lin 20 30 1 8 W 71450 XQS 200 obd A4R15 0687 1031 fxd comp 10 10 1 2 W 01121 EB1031 A4R16 0687 1041 fxd comp 100 10 1 2 W 01121 1041 A4R17 0687 1241 fxd comp 120 10 1 2 W 01121 1241 4 18 0687 1031 fxd comp 10 10 1 2 W 01121 EB1031 A4RI19 0687 1021 fxd comp 1000 2 10 1 2 W 01121 1021 A4R20 0687 1041 fxd comp 100 10 1 2 W 01121 1041 A4R21 0687 2231 fxd comp 22 10 1 2 W 01121 EB2231 A4R22 0687 1241 fxd comp 120 10 1 2 W 01121 EB1241 A4R23 thru 0687 1021 fxd c
23. are provided onthe rear panel The voltage available is proportional to the meter deflection and is adjustable from 0 to 1 voit at full scale 1 9 INSTRUMENT MANUAL IDENTIFICATION 1 10 Hewlett Packardusesa two section eight digit serialnumber 000 00000 If the first three digits of the serial number on your instrument do not agree with those on the title page of this manual change sheets supplied with the manual willdefine differences between your instrument and the Model419A described in this manual j 01779 2 INFORMATION 1 11 ACCESSORY EQUIPMENT SUPPLIED 1 12 The accessory equipment supplied with each Model 419A is listed and described in Table 1 2 Table 1 2 Accessory Equipment Supplied IDENTIFICATION NUMBER QUANTITY DESCRIPTION 0419 90002 Operating and Service Manual 0 1 13 ACCESSORY EQUIPMENT AVAILABLE 1 14 The accessory equipment available is listed in Table 1 3 For further information contact your local hp Sales and Service Office See Appendix B for office locations Table 1 3 Accessory Equipment Available IDENTIFICATION NUMBER DESCRIPTION 22 Pin Printed Circuit 9060 0630 Board Extender Dual Banana Plugs to Dual Banana Plugs 44 Dual Banana Plugs to Alli 110024 gator Clips 60 Dual Banana Plugs to Probe 110034 and Alligator Clip 60 1 1 HP 419A Null Voltmeter max Model 419A Section SECTION Il INSTALLATION 2 1 INTRODUCTION 2 2
24. from 90 to 1000 Hz The input is rectified by thru CR4 and applied to series regulator Ql 4 38 Zener diode CR5 supplies a constant reference to the baseof Q1 The emitter of Q1 is referencedto the voltage across 2 R3 1 the output current creases Q1 will conduct less due to less emitter to base bias This will decrease the output current If either output decreases 01 will conduct harder in creasing the output current 4 39 The neon driver consists of a series regulator circuit a blocking oscillator and a neon circuit Transistor Q5 andzener diode CR9 provide a constant reference to series regulator Q4 frequency of the blocking oscillator is controlled by varying the voltage across C3 Thisis accomplishedthrough ad justable resistor R9 which controls the bias on the base of Q4 4 40 Due to inherent characteristics either Q2 or Q3 will conduct harder when powerisapplied Assume that Q2 conducts more than Q3 As Q2 conducts a negative going signalis coupled through TZ2to the base 01179 2 Section IV of 03 This causes Q3 to cut off completely At the same time a positive going signal is coupled to the base of 02 causing it to conduct more While 02 is conducting a negative output will be coupled to the neon circuit 4 41 When T2becomes saturated the positive signal is removed from the base of Q2 and it cuts off At the same time the negative signal is removed from the base of Q3 all
25. hp part number information 5 26 The etched circuitboards are a plated through type The electrical connection between sides of the board is made by a layer of metal plated through the component holes When working on these boards observe the following general rules 9 3 HP 419A DC Null Voltmeter max Section V a To avoid contamination wear clean lint free cotton or rubber gloves b Use alow heat 25 to 50 watts small tip sol dering iron and a small diameter rosin core solder Circuit components canbe removed by placing the soldering iron on the component lead on either side of the boardand pulling up on lead Ifa component is obviously damaged clip leads as close to component as possible and then remove Excess heat can cause the circuit and board to separate or cause damage to the component Component lead hole shouldbe cleaned before inserting new lead e To replace components shape new leads and insert them in holes Reheat with iron and add solder as required to insurea good elec trical connection f Cleanexcess fluxfrom the connection and ad joining area g To avoid surface contamination of the printed circuit clean with weak solution of warm water and mild detergent after repair Rinse thor oughly with clean water When completely dry spray lightly with Krylon 1302 or equi valent 5 27 INSTALLATION OF REPLACEMENT NEON SUBASSEMBLY hp Part No 1990 0214 5 28 Physical alig
26. of the RANGE Switch In the 3 uV to 1 mV range re sistor R7 is shorted out decreasing the negativefeed back applied to Q1 4 25 Feedback from the emitters of Q6 and Q7 isalso controlled to vary the gain of Q4thru Q7 In the 34V to 100 uV range resistor R16 is shorted out decreasing the negative feedback appliedto Q4 Capacitors A3C4 and A4C9 couple the ac input and output and block the dc bias voltages 4 26 DC AMPLIFIER 4 27 The output of the demodulator is applied to a four stage voltage and power amplifier Q9 provides temperature compensation for the circuit When Q8 and Q9 increase conduction due to a rise in tempera ture the emitter to base voltage of Q4 decreases which decreases the Q8 forwardbias This maintains Q8 conduction at a constant level 4 28 The final stage of amplification is a compli mentary symmetry amplifier consisting of Q12 013 CR13 and CR14 diodesbias the transistors at a constant idling state with no input signal applied When aninput isapplied the transistor responds im mediately with an output input does not have to reach a certain amplitude to cause conduction in the transistors since they are already at an idling con dition 4 29 The output of the dc amplifier willbe 1 V for end scale input on all ranges output is also plied to the and OUTPUT terminals J5 and J6 Adjustable resistor R2 provides control of the recorder output from 0 to 1 volt end scale
27. operate properly and the batteries should be at least partially recharged before using the instrument Generally 72 hours of trickle charging will restore the batteries to their fully charged state however the batteries may be trickle charged indefinitely without damage 3 15 Thebatteries may be fast charged by connecting the Model 419A to an ac powerline and depressing the FAST CHG pushbutton The instrument cannotbe used to make measurements while fast charging the batteries The batteries should reach full charge inapproximately 15 hours 3 16 To obtain maximum battery life the following points should be observed a Do not allow the batteries to discharge below the BAT limits on the meter scale b Use fast charge only when necessary Chargethebatteries in moderate temperatures 80 F 10 F 27 5 6C whenever possible d Do not store the instrument at temperatures above 1229F 509C or below 40 209C 3 17 APPLICATIONS 3 18 In addition to straightforward dc voltage and current measurements the Model 419A has a number of applications Severalof these are presented inthe following paragraphs 3 19 Measuring Leakage 3 20 By using the Model 419A as a sensitive dc am meter very high resistance leakage paths in insulating materials can be detected and measured Leakage is observedby connecting the output of a dc power supply across the insulating material and placing the Model 419A in series
28. receptacle groundsthe instrument offset pin on the power cable three prong connector is the ground wire 2 9 Topreservethe protectionfeature when operating the instrument from a two contact outlet use a three prongtotwo prong adapter and connect the green pig tail on the adapter to ground 2 10 INSTALLATION 2 11 The Model 419 is fully transistorized there fore no special cooling is required However the instrument should not be operated where the ambient temperature exceeds 509C 1229F 2 12 BENCH MOUNTING 2 13 The Model 419A is shipped with plastic feet and tilt stand in place ready for use as a bench instru ment 2 14 RACK MOUNTING 2 15 The Model 419A may be rack mounted by using an Adapter Frame hp Part No 5060 0797 The 01779 2 adapter frame is a rack frame that accepts any com bination of submodular units It can be rack mounted only For additional information address inquiries to your hp Sales and Service Office See Appendix B for office locations 2 16 COMBINATION MOUNTING 2 17 The Model 419A may be mounted in combination withother submodular units by using a Combining Case hp Models 1051A and 1052A The Combining Case is a full module unit which accepts various combina tions of submodular units Being a full module unit it can be bench or rack mounted and is analogous to any full module instrument 2 18 REPACKAGING FOR SHIPMENT 2 19 Thefollowing par
29. with one of the power supply leads By noting the currentflow on the Model 419A the leakage resistance can be calculated from the formula E R power supply leakage 1 419A Example Assume the leakage between 2 points A and in a standards laboratory oil bath is to be measured A 100 V power supply and the 419A are connected as shown in Figure 3 2 01779 2 419A Null Voltmeter max Model 419A Section III 3 21 Calibrating A Voltage Source 3 22 The Model 419A can serve as a very sensitive hp AISA and accurate null detector These features can be BATTERY OPERATION especially useful when matching the output of an ad justable voltage source to a reference standard The adjustable voltage source and the reference standard are connected in series opposition withthe Model 419A serieswithone of the leads The adjustable voltage source is then adjusted for a null indication on the Model 419A POWER SUPPLY Example Assume the output of a dc standard hp Model 741B is tobe matched tothe output of a 1 Vtrans OIL BATH fer standard hp Model 735A These instru ments and the Model 419A connected as shown in Figure 3 3 The reference standard and the adjustable voltage source are both set for a output The Model 419A indicates any deviations between the two out Figure 3 2 Leakage Measurement puts By making internal adjustments affecting the output of the voltage sour
30. 201 6 25 V Battery mercury 1 34 V cylindrical BT5 1420 0004 316469 081 2140 0008 Lamp glow type 2 neon 2140 0008 Fi 2110 0027 Fuse cartridge 1 8 amp 250 V 312 125 Ji 1251 0148 J2 5080 1278 1061 2 5080 1278 Connector ac power cord receptacle Binding Post red with solder turret INPUT 0340 0159 Insulator Cup binding post 0340 0159 0340 0100 Insulator Spacer binding post 0340 0100 00419 21701 Guard binding post threaded 00419 21701 5080 1277 Binding Post black with solder turret 5080 1277 INPUT Insulator Cup binding post 0340 0159 0340 0159 0340 0100 Insulator Spacer binding post 0340 0100 00419 21701 Guard binding post threaded 00419 21701 1510 0011 Binding Post black with solder turret 1510 0011 0340 0099 Insulator binding post 0340 0099 1510 0010 Binding Post red with solder turret 1510 0010 OUTPUT Binding Post black with solder turret OUTPUT Binding Post black with solder turret 4 Insulator binding post dual Insulator binding post triple 1510 0011 1510 0011 1510 0011 0340 0086 0340 0091 1510 0011 0340 0086 0340 0091 9100 1318 Inductor input 9100 1318 1120 0312 Meter 1120 0312 2100 1557 R var prec ww 10 turn 100 5 2 W Series 62 CM 33147 2100 2200 R var lin 20 20 1 3 W Series 45 0698 3463 fxd prec
31. 233 1141 TWX 810 751 3283 UNITED STATES and CANADA HAWAII EU North Hollywood Calif 91604 3939 Lankershim Blvd 213 877 1282 TWX 910 499 2170 ILLINOIS Skokie 60076 5500 Howard Street 312 677 0400 TWX 910 223 3613 INDIANA indianapolis 46205 3919 Meadows Dr 317 546 4891 TWX 317 635 4300 LOUISIANA New Orleans 504 522 4359 MARYLAND Baltimore 21207 6660 Security Blvd 301 944 5400 TWX 710 862 0850 Rockville 20852 12303 Twinbrook Pkwy 301 427 7560 TWX 710 828 9684 MASSACHUSETTS Burlington 01803 Middlesex Turnpike 617 272 9000 TWX 710 332 0382 MICHIGAN Southfield 48076 24315 Northwestern Hwy 313 353 9100 TWX 313 357 4425 MINNESOTA St Paul 55114 2459 University Ave 612 646 7881 TWX 910 563 3734 MISSOURI Kansas City 64114 9208 Wyoming Place 816 333 2445 TWX 910 771 2087 St Louis 63144 2812 South Brentwood 314 644 0220 TWX 910 760 1670 NEW JERSEY Eatontown 07724 201 74 1060 Englewood 07631 391 Grand Avenue 201 567 3933 TWX 510 230 9709 NEW MEXICO Albuquerque 87108 6501 Lomas Blvd 505 255 5586 TWX 910 989 1655 Las Cruces 88001 114 Water Street 505 526 2486 TWX 910 983 0550 NEW YORK New York 10021 236 East 75th Street 212 879 2023 TWX 710 581 4376 Rochester 14623 39 Saginaw Drive 716 473 9500 TWX 510 253 5981 Poughkeepsie 12601 82 Washington Street 914 454 7330 TWX
32. 3 Paragraph 5 34 step e gives specific replacement in structions 5 55 A4R47 5 56 A4R47 is factory selected to provide approxi mately 1 1 Vdc at the rear panel OUTPUT terminals into 1 load with the LEVEL control turned fully cw anda full scale input applied to the INPUT ter minals Once A4R47 hasbeen selected at the factory there should be no reason to change its value unless one of the output transistors A4Q12 and A4Q13 or one of the diodes A4CR13and A4CR14is replaced Factory values of A4R47 range from 16 to 20 with a typical value of 18 A4R47 is an Allen Bradley composition 5 1 2 watt resistor If the value of A4R47 must be changed proceed as follows a Applya 1Vdc inputto the Model 419A INPUT terminals 1 V range b Connect a 1 load across the rear panel OUTPUT terminals c Turn LEVEL control fully cw d Measure the voltage across the load If the voltage islessthan 1 0 Vdc increase the value of A4R47 if the voltage is greater than 1 15 Vdc reduce the value of A4R47 e After replacing A4R47 perform the Full Scale Calibration procedure Paragraph 5 37 01779 2 419A DC Null Voltmeter max Model 419A section VI SECTION VI CIRCUIT DIAGRAMS 6 1 INTRODUCTION are provided for the metering circuit and the power 6 2 This section contains the circuit diagrams nec supply circuit essary for the operation and maintenance of the Model 419A DC Null Voltm
33. 419A DC NULL VOLTMETER OPERATING AND SERVICE MANUAL J HEWLETT i PACKARD il HEWLETT ill PACKARD CERTIFICATION The Hewlett Packard Company certifies that this instrument was thoroughly tested and inspected and found to meet its published specifications when it was shipped from the factory The Hewlett Packard Company further certifies that its calibration measurements are traceable to the U S National Bureau of Standards to the extent allowed by the Bureau s calibration facility WARRANTY AND ASSISTANCE Hewlett Packard products are warranted against defects in materials and workmanship This warranty applies for one year from the date of delivery or in the case of certain major components listed in the operating manual for the specified period We will repair or replace products which prove to be defective during the warranty period No other warranty is expressed or implied We are not liable for consequential damages For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual HP 419A DC Null Voltmeter max Il MANUAL OPERATING AND SERVICE HP PART NO 00419 90002 MODEL 419A DC NULL VOLTMETER SERIALS PREFIXED 707 Appendix C Manual Backdating Changes adapts this manual to Serials Prefixed 514 532 646 Copyright Hewlett Packard Company 1966 Box 301 Loveland Colorado 80537 U S A Printe
34. 4i9A B 1002 HP 419A DC Null Voltmeter max SIR26 IK an 220K ph pon e SO EM C 390R 120K SOK 5189 3300 55 om B 9 SI RANGE SWITCH e e Q e 18 o SIAR Q9 9 1 PARTIAL REFERENCE WITH ASSEMBLY OR 5 FOR COMPLETE DESI 2 COMPONENT VALUES WISE NOTED RESISTANCE IN CAPACITANCE 3 DENOTES POWER DENOTES POWER DENOTES SIGNAL 4 COME ein ar po Pe ums mnl m 104 5 DENOTES FR pu L____ DENOTES 5 DENOTES SCF BTS C d R6 2200 NULL COARSE 11300 Mv MAX R4 RE e5K 1506 ae R1 220 NOTES 1 PARTIAL REFERENCE DESIGNATIONS ARE SHOWN PREFIX 7 4824 DENOTES WIRE COLOR COLOR CODE SAME AS RESISTOR WITH ASSEMBLY OR SUBASSEMBLY DESIGNATION S OR BOTH COLOR CODE FIRST NUMBER IDENTIFIES BASE COLOR FOR COMPLETE DESIGNATION SECOND NUMBER IDENTIFIES WIDER STRIP THIRD NUMBER IDENTIFIES NARROWER STRIP 2 COMPONENT VALUES ARE SHOWN AS FOLLOWS UNLESS OTHER e g 4924 WHITE RED YELLOW WISE NOTED RESISTANCE IN OHMS CAPACITANCE IN MICROFARADS WIRE COLOR 3 ab DENOTES POWER LINE CHASSIS GROUND VW DENOTES POWER SUPPLY COMMON DENOTES SIGNAL COMMON DENOTES ASSEMBLY
35. 5 DC 1 EB 1025 EB1531 4633 4147 250 22 30 210 9000 0716 5000 0702 5060 0717 241 44 5060 0728 5040 4524 5040 0615 342014 00419 04301 0370 0121 0370 0137 0370 0112 5000 3217 5000 3216 1 5 Section Table 7 1 Replaceable Parts Cont d Model 419A REFERENCE hp DESIGNATOR PART NO DESCRIPTION P MFR PART NO 1 6 9000 0251 5000 3213 5000 3214 5000 3345 5000 3215 00419 90002 00419 00201 00419 00202 00419 00606 00419 00601 00419 00602 00419 00604 00419 00603 00419 00605 1490 0032 Label Label Label Label Label Manual Panel Panel Shield Shield Shield Shield Shield Shield Stand pushbutton OFF pushbutton READ NULL pushbutton SET NULL pushbutton VM AM pushbutton ZERO Operating and Service front rear bottom front rear side left side right top half module tilt stainless steel rod HP 419A DC Null Voltmeter max 5000 0251 2000 3213 5000 3214 2000 3345 5000 3215 00419 90002 00419 00201 00419 00202 00419 00606 00419 00601 00419 00602 00419 00604 00419 00603 00419 00605 01779 2 Model 419A APPENDIX CODE LIST OF MANUFACTURERS Sheet 1 of 2 Appendix A The following code numbers are from the Federal Supply Code tor Manufacturers Cataloging Handbooks H4 1 Name to Code and H4 2 Code to Name and their latest date of revision and the date of the suppleme
36. 5 4 e l eleele Figure 6 3 Amplifier and Amplifier Switching Schematic and Component Location Diagrams 01779 2 6 3 6 4 HP 419A DC Null Voltmeter max CURRENT RED WHT BLK Sk FREQ VL 2 CR5 R8 RIO cri o mm CR2 C3 9 ore cR9 9 419 0999 WHT WHT GRY WHT YEL GRY BRN BRN RED VIO WHT BLK WHT GRN BLK BLK GRY GRY A2 RED Ap Part 00419 66502 i 1 PARTIAL REFERENCE DESIGNATIONS ARE SHOWN PREFIX WITH ASSEMBLY OR SUBASSEMBLY DESIGNATION S OR BOTH FOR COMPLETE DESIGNATION 2 COMPONENT VALUES ARE SHOWN AS FOLLOWS UNLESS OTHER WISE NOTED RESISTANCE IN OHMS CAPACITANCE IN MICROFARADS 3 zl DENOTES POWER LINE CHASSIS GROUND W DENOTES POWER SUPPLY COMMON DENOTES ASSEMBLY DENOTES SUBASSEMBLY DENOTES COMPONENTS MOUNTED ON ASSEMBLY 5 _ _ DENOTES REAR PANEL MARKING 6 DENOTES SCREWDRIVER ADJUST 7 4924 DENOTES WIRE COLOR COLOR CODE SAME AS RESISTOR COLOR CODE FIRST NUMBER IDENTIFIES BASE COLOR SECOND NUMBER IDENTIFIES WIDER STRIP THIRD NUMBER IDENTIFIES NARROWER STRIP e g 924 WHITE RED YELLOW WIRE COLOR 0 1 2 3 4 5 6 1 8 9 8 INDIVIDUAL COMPONENTS 1 ARE NOT SEPARATELY REPLACEABLE SEE PARAGRAPH 5 27 HP 419A DC Null Vo
37. 59 OA RE AE SOR CA SIR20 100 51 Vy RANGE SWITCH S2 FUNCTION SWITCH FAST BAT VM ET READ Oo Oo o 0 419A 4 0963 419A Null Voltmeter max NOTES 7 4924 DENOTES WIRE COLOR COLOR CODE SAME AS RESISTOR COLOR CODE FIRST NUMBER IDENTIFIES BASE COLOR SECOND NUMBER IDENTIFIES WIDER STRIP THIRD NUMBER IDENTIFIES NARROWER STRIP RANGE fe g 4924 WHITE RED YELLOW AMPLIFIER ASSEMBLY 00419 66504 SIBIR WIRE COLOR 2 1 3 EO 5 8 8 AVERAGE VALUE SHOWN OPTIMUM VALUE SELECTED o i FACTORY SEE PARAGRAPH 5 51 FOR REPLACEMENT INSTRUCTIONS o 9 DENOTES TWISTED PAIR 10 VOLTAGES INDICATED IN RED ARE MEASURED WITH 9 PUSHBUTTON DEPRESSED 1 V RANGE INPUT SHORTED ALL VOLTAGES ARE 10 i 9 Ko E 6 MODULATOR 49 052 7 RANGE Y zd 9 SIR27 c4 LU 3 5 L2 Q E iin I os p id e ee SIBE SIBIR j E 2 5 a et fe o PHOTO CHOPPER ASSEMBLY 00419 63001 5 5 8 SIR24 a p S 96 5 snes 2 5 8 RC 4 7 i R3 90M 49 9 9 m 2 e 0 C c4 t 2555 25 09 O 3 3 9 IV ZERO 51 22 e 2 RE A i RIA 51821 9 49 oe 900 1820 9 29 T
38. 7 NOISE TEST Ifnoise displayed on 419A meter exceeds 0 3 Set 419A RANGE switchto 3 LV position de perform Chopper Adjustment Para press VM AM pushbutton graph 5 33 5 2 01779 2 419A Null Voltmeter max Model 419A TEST OSCILLATOR hp 208A 419A B 0291 Section V hp 419A DC NULL VOLTMETER Figure 5 3 Superimposed AC Rejection Performance Test Setup 5 19 INPUT RESISTANCE TEST 5 20 A Voltmeter Calibrator hp Model 738BR a 10 resistor hp Part No 0698 3193 100 resistor hp Part No 0698 4057 a 1 MQ resistor hp Part No 0757 1054 and a 10MQ resistor hp Part No 0698 4128 are required for this test a Connecta 10 kQresistor to Model 419A IN PUT terminal b Connect voltmeter calibrator dc output ter minalsto 10 INPUT terminal on the Model 419A Set Model 419A RANGE to set voltmeter calibrator output to 3 mV 003 V d The Model 419A should indicate 2 73 mV which verifies an input resistance of 100 on the 3mV range asgivenby thefollowing formula R X 5m E E In where is the 419A input resistance Rg is the series resistance is the voltage indicated on the Model 419A meter and is the voltmeter calibrator output voltage NOTE The input resistance may vary slightly anda tolerance of 3 shouldbe allowed e Replace the 10 resistor with a 100 kQre
39. 79 86584 87215 87473 87664 87930 88140 88220 88698 89231 89462 89473 89635 89665 90179 90970 91260 91345 81418 91506 91637 81662 91737 81827 81529 91961 92180 92196 92367 42607 33332 93369 93410 93788 APPENDIX Address Manufacturer Bracamonte amp Co Koiled Kords Inc San Francisco Calif New Haven Conn Seamless Rubber Co Chicago lil Clifton Precision Products Clifton Heights Precision Rubber Products Carp Dayton Ohio Radio Corp of America RCA Electron Tube Div Philco Corporation Lansdale Division Harrison N J Lansdale Pa Western Fibrous Glass Products Co San Francisco Calif Seattle Wash Providence 1 Lincoln St Minn Buffalo Van Waters amp Rogers Inc Tower Mfg Corp Cutler Hammer Inc Gould National Batteries Inc General Mills Inc Graybar Electric Oakland Calif Waldes Koninonr Inc Cambridge Mass General Electric Distributing Corp Schenectady Carter Parts Div of Economy Baler Chicago United Transformer Chicago U S Rubber o Mechanical Goods Div Passaic N J San Francisco Calif San Francisco Calif EI Monte Calif Chicago Attleboro Mass Columbus Nebr Philadelphia Pa Gremar Mfg Co Inc Wakefield Mass K F Development Co Redwood City Calif Minneapolis Honeywell Regulator Microswitch Div Freeport
40. A2R3 0687 5611 A2R4 0687 3331 A2R5 2100 1410 0687 4731 0686 5105 2100 0362 0687 4721 0687 1051 0687 4741 A2R6 AZR7 A2R8 9100 0172 9100 1319 00419 63001 1990 0214 1 A3C2 A3C3 0160 0859 0170 0064 0160 2446 1 2 A3CR4 1901 0156 A3R1 A3R2 A3R3 0811 1505 thru A3V4 00419 63001 00419 66504 0180 0224 0180 0060 0150 0069 0180 0100 0150 0069 1 2 REFERENCE hp TQ DESIGNATOR PART NO 1 Table 7 1 Replaceable Parts DESCRIPTION MFR PART NO Not Assigned Assembly Power Supply C fxd Al elect 65 uF 100 10 60 C fxd 0 01 uF 80 20 100 vdew C fxd elect 10 pF 100 10 25 vdew C fxd 0 01 pF 10 Diode Si 100 mA at 1 V 100 piV 12 pF Diode breakdown 6 81 V 5 Diode Si 100 mA at 1 V 100 piV 12 pF Diode breakdown 100 pA 22 1 V 2 Transistor NPN Si 2N3053 Transistor NPN Si 2N3391 Transistor PNP Si fxd comp 150 10 1 2 W fxd comp 750 Q 5 1 2 W fxd comp 560 Q 10 1 2 W fxd comp 33 10 1 2 W var lin 20 30 1 8 W fxd comp 47 10 1 2 W fxd comp 51 Q 5 1 2 W var lin 100 30 1 8 W fxd comp 4700 0 10 1 2 W fxd comp 1 MQ 10 1 2 W fxd comp 470 10 1 2 W muU Transformer power Transformer neon driver Assembly Photochopper Subassembl
41. CE OFFICES Appendix C MANUAL BACKDATING CHANGES LIST OF TABLES Section Page I GENERAL INFORMATION 1 1 1 1 1 1 1 3 1 1 1 5 Description and Purpose 1 1 1 9 Instrument Manual Identification 1 1 1 11 Accessory Equipment Supplied 1 1 1 13 Accessory Equipment Available 1 1 Section Page I INSDLTALDATION 5504 5542 wo Sa 2 1 2 1 Introduction 2 1 2 3 Initial Inspection 2 1 2 5 Power Requirements 2 1 2 7 Grounding Requirements m 2 1 2210s Installation x e Woo 2 1 2 12 Bench Mounting 2 1 2 14 Rack Mounting 2 1 2 16 Combination Mounting 2 1 2 18 Repackaging for Shipment 2 1 Section Page OPERATING INSTRUCTIONS 3 1 3 1 Introduction 8 1 3 3 Controls Indicators andConnectors 3 1 3 5 Operating Instructions 3 1 3 7 Turn On Procedure Battery 3 1 3 8 Turn On Procedure Line 3 1 3 9 DC Voltage Measurements 3 1 3 10 DC Current Measurements 3 2 3 17 3 2 Section Page IV THEORY OF OPERATION 4 1 4 1 4 1 4 3 General Description 4 1 4 11 Detailed Description 4 4 12 Bucking Supply See Figure 6 3 4 1 4 15 Input Attenuator 4 2 4 17
42. Co Louis Mo Chicago Candenser Corp Chicago lli OTS Corp Elkhart Ind Cannon Electric Co Cinema Engineering amp Co Centralab Div of Giobe Union Inc Milwaukee Wis Los Angeles Calif Burbank Calif Chicago lil Commercial Plastics Chicago The Cornish Wire Co New York M Y Chicago Miaiature Lamp Works Chicago 111 Smith Corp Crowley Div West Orange Chicago IH Midiand Mich San Bruno Calif Cinch Mfg Corp Dow Corning Corp Eitei McCullough Inc Electro Motive Mfg Co Inc Willimantic Conn Providence R i Chicago Brooklyn N Y Keasbey Coto Coil Co Inc Jobn E Fast amp Dialight Corp General Ceramics Corp General Instrument Corp Semiconductor Div Girard Hopkins Newark 1 Oakland Calif Drake Mfg Co Chicago IIl Hugh Eby lac Philadelphia Pa Gudeman Chicago Robert M Hadley Co Los Angeles Calif Erie Resistor Corp Erie Pa Hansen Mfg Co Inc Princeton ind Harper Co Chicago 11 Helipot Div of Beckman Instruments Inc Fullerton Calif HP 419A DC Null Voltmeter max Rochester N Y Code No 73293 73445 73490 73506 73559 73682 73734 73743 1379 73846 73899 73805 74276 74455 74861 14868 74970 75042 75173 15378 75382 75818 75315 75005 16210 16433 16487 16493 75530 76545 16854 77068 11075 7221
43. DENOTES SCREWDRIVER ADJUST 300 7 9 V DENOTES POWER SUPPLY COMMON MICROVOLT 5 VOLTS o 1000 18 40 DENOTES SIGNAL COMMON 11 DENOTES POWER LINE GROUND o 12 77 DENOTES COMPONENTS MOUNTED ON ASSEMBLY 7777 OD 13 DENOTES MAIN SIGNAL PATH 15 o f git J2 52 SID F E SIR27 azca ESO pe LI L2 OHF C 2o 52 2 3 SIB R 53 J3 2 4 O 4 Q 3 54 cy 56 2 4 6 a 5 6 6 5 5 J4 lt gt Q T 7 6 1 RR 7 a 8 QD o 9 9 o 9 g i m 10 Io o Il o le R3 2 790M 20 3 13 o 5 13 9 14 14 51825 4 SOK 14 5 O 16 alt 15 o o SIR22 17 l o o 8 ia T Fe To 8 8 Ie 8 8 a 18 SIRZO ASRS 100 190 2 419A D O2678 HP 419A DC Null Voltmeter max AC DC AMPLIFIER ASSEMBLY 00419 66501 PREFIX WITH ASSEMBLY OR SUE di SE sm l LETE DESIGNATION SIBI UNLESS OTHERWISE NOTED 2 3 AX b BACK PATH BACK PATH R27 IM o 7 o m MOUNTED ON ASSEMBLY INAL PATH 1 0 99 SiB SIB RI R30 470K min jo fo 1 nm o 9 Oo e jo m o o IV ZERO 5 m R25 IK p z nm 45 o
44. EX NO Gee 960 OOOO 9 3 0 HEWLETT PACKARD 4194 DC NULL VOLTMETER Figure 3 1 Meter LINE Indicator and INPUT terminals Ground LL terminal OFF FAST CHG BAT TEST ZERO VM AM SET NULL READ NULL ZERO control NULL control RANGE switch LEVEL control and OUTPUT terminals Line Voltage Switch FUSE 1 8 A AC Power Connector MV N RANGE 3 10 30 o 300 Model 419 2 LEVEL OUTPUT BA QO R 26 17 419A C 0270A FUNCTION Indicates value of applied voltage or current in conjunction with RANGE switch and function pushbuttons Lights to indicate application of ac line voltage to power supply circuits Accepts leads for application of dc voltage or current input Accepts lead for grounding of instrument case When depressed all functions are turned off When depressed enables batteries to charge at a fast rate When depressed enables meter to indicate battery voltage When depressed internally disconnects voltmeter from terminal and shorts to terminal When depressed enables meter to indicate value of input voltage or current When depressed places null supply in series opposition to input voltage When depressed enables meter to indicate value of null supply Provides continuously variable control of zero offset to 15 pV Provides continuously variable control for nulling of input
45. Pa Tru Prod Div of Model Engineering and Mfg Co Chicago Wire Cloth Products inc Chicago Ill Worcester Pressed Aluminum Corp Worcester Mass Boston Mass Miami Fla Woodside N Y New York N Y Burbank Calif Sheridan Wyo Bridgeport Conn Philbrick Researchers Inc Allies Products Corp Continental Connector Carp Leecraft Mfg Co Inc Lerco Electronics Inc National Coil Co Vilramon Inc Gordas Corp Bloomfield N J Methode Mfg Co Chicago Ill Dage Electric Co inc Franklin Ind Weckesser Chicago Huggins Laboratories Sunnyvale Calif Hi Q Division of Aerovox Olean N Y Thordarson Meissner Div of Maguire Industries Inc Mt Carmel 11 Solar Manufacturing Co Los Angeles Calif Carlton Screw Co Chicago Microwave Associates Inc Burlington Mass Excel Transformer Oakland Calif industrial Retaining Ring Irvington N J Aulomatic and Precision Mfg Co Yonkers N Y CBS Electronics Div of C B S Inc Reon Resistcr Corp Axel Brothers Inc Rubber Teck Inc Danvers Mass Yonkers N Y Jamaica N Y Gardena Calif HP 419A DC Null Voltmeter max Code 98220 98278 98291 98405 98731 98821 98925 98978 99108 99313 99515 99707 99800 39848 99934 99942 99957 Model 419A Address Manufacturer Francis L Mosley Pasadena Calif Microdot inc So Pasadena Calif Sealectra Corp Mamaroneck N Y
46. This section contains information and instruc tions necessary for the installation and shipping of the Model 419A DC Null Voltmeter Included are ini tial inspection procedures power and grounding re quirements installation information and instructions for repackaging for shipment 2 3 INITIAL INSPECTION 2 4 This instrument was carefully inspected both mechanically and electrically before shipment It should be physically free of mars or scratches and in perfect electricalorder uponreceipt Toconfirmthis the instrument should be inspected for physical damage intransit Also check for supplied accessories and testthe electrical performance of the instrument using the procedure outlined in Paragraph 5 5 If there is damage or deficiency see the warranty on the inside front cover of this manual 2 5 POWER REQUIREMENTS 2 6 The Battery Power Supply in the Model 419A can be charged from any source of 115 or 230 volts 21096 at 50 to 1000 Hz With the instrument dis connected from the ac power source move the slide switch located on the rear panel until the desired line voltage appears Power Dissipation is approxi mately 3 watts 2 7 GROUNDING REQUIREMENTS 2 8 To protect operating personnel the National Electrical Manufacturers Association NEMA re commends that the instrument panel and cabinet be grounded This instrument is equipped with a three conductor power cable which when plugged into an appropriate
47. agraphs containa general guide for repackaging of the instrument for shipment Re fer to Paragraph 2 20 if the original container is to be used 2 21 if it is not If you have any questions contact your local hp Sales and Service Office See Appendix B for office locations NOTE Ifthe instrument is to be shipped to Hewlett Packard for service or repair attach a tag to the in strument identifying the owner and indicatingthe service or re pair to be accomplished include the model number and full serial number ofthe instrument correspondence identify the in strument by model number serial number and serial number prefix 2 20 If original container is to be used proceed as follows a Place instrument in original container If original container is not available one can be purchased from your nearest hp Sales and Service Office b Ensure that container is well sealed with strong tape or metal bands 2 21 If original container is not to be used proceed as follows a Wrapinstrument inheavy paper or plastic be fore placing in an inner container b Place packing material around all sides of instrument and protect panel face with card board strips c Place instrument and inner container in a heavy carton or wooden box and seal with strong tape or metal bands d Mark shipping container with DELICATE INSTRUMENT FRAGILE etc 2 1 HP 419A DC Null Voltmeter max Section IND
48. and Rear Panel Controls Indi cators and Connectors 3 0 3 2 Leakage Measurement 3 3 3 3 Calibrating a DC Standard 3 3 3 4 Measuring Power Supply Drift 3 4 4 1 Model 419A Block Diagram 4 0 5 1 Voltmeter Accuracy Performance UND de u Wr eoe c XE ene En 5 0 5 2 Ammeter Accuracy Test Setup 5 2 5 3 Superimposed Rejection Per formance Test Setup 5 3 iv Schematic and Component Location e 4 6 5 01779 2 HP 419A Null Voltmeter max Section I Model 419A Figure 1 1 Model 419A DC Null Voltmeter Table 1 1 Model 419A Specifications VOLTMETER Output 0 to 1 volt at 1 mA max for end scale reading Output level is adjustable for convenience when used with recorders Ranges 3 to 1000 volts dc end scale in 18 zero center ranges Output Impedance Depends on setting of output level control lt 35 ohms when output level is set to maximum Noise 0 01 Hz to 5 Hz Sameas voltmeter referred to input gt 5 Hz rms noise lt 10 mV referred to output Accuracy 2 of end scale 0 1 pV Limits of Zero Control 15 pV Input Resistance 3 LV to 3 mV ranges 100kQ infinite whennulled 10 mV to 30 mV ranges 1 9 infinite when nulled DC AMMETER Current Ranges 30pA 100 pA 300 pA 1 3 nA x10 nA 30 nA Accuracy 3
49. ara Paragraph 5 49 graph 5 33 Table 5 3 Ammeter Accuracy Test 9 15 SUPERIMPOSED AC REJECTION TEST VOLTMETER STEP CALIBRATOR DC OUTPUT 419A 9 16 The superimposed ac rejection test setup is il READING lustrated in Figure 5 3 An oscillator hp Model 208A a 600 2 resistor hp Part No 0727 0081 28 110 31 9 10 resistor hp Part No 0684 1031 and a 0 1 capacitor hp Part No 0170 0085 are required 96 to 104 for this test 290to 310 970 to 1030 2910 to 3090 9 7 to 10 3 29 1 to 30 9 a Connect test setup illustrated in Figure 5 3 do not connect oscillator b Depress 419A SET NULL pushbutton set NULL control for 9 on 10 pV range Connect oscillator and set its output frequency 5 13 RESPONSE TIME TEST for 60 Hz output voltage for 0 5 volts rms 5 14 A strip chart recorder Sanborn Model 7701A ae E not ud Morean a voltmeter calibrator Model 738BR a 100 0 resistor hp Part 0811 0398 and a 1 MQ re sistor hp Part No 0811 0473 are required for us teat 5 18 No external test equipment is required forthe a Connect strip chart recorder to 419A and noise test a Short 419A and INPUT terminals b Construct test setup illustrated in Figure 5 1 turn voltmeter calibrator dc output off and b Zero 419A VM function on pV RANGE setfor 30 mV output connect 419A INPUT terminal to Point 5 1
50. c Components Dept Digitran Transistor Electronics Corp Westinghouse Electric Corp Flectronic Tube Div Filmothim Corp Cinch Graphik Co Avnet Corp Fairchild Semiconductor Corp Mountain View Calif Minneapolis Minn Los Angeles Calif Technica Wire Products Springfield 1 Continental Device Corp Hawthorne Calif Rheem Semiconductor Corp Mountain View Calif Shockley Semi Conductar Laboratories Boonton Radio Corp U S Engineering Blinn Delbert Co Burgess Battery Co Niagara Falis Ontario Canada Burbank Calif Bradford Pa Pasadena Calif Minneapolis Mian Elmira New York City of Industry Calif Los Angeles Calif Minnesota Rubber The Birtcher Corp Palo Calif Boonton Los Angeles Calif Pomona Stoan Company Cannon Electric Co Phoenix Div CBS Electronics Semiconductor Operations Div ol 5 1 Mel Rain Babcock Relays Inc Texas Capacitor Co Atohm Electronics Electro Assemblies Inc Mallory Battery Ca af Canada Ltd The Bristol General Transistor Western Corp Los Angeles Calif Berkeley Calif Niagara Falls Berne Ind Lowell Mass indianapolis Ind Costa Mesa Calif Houston Texas Sun Valley Calif Chicago MI Toronto Ontario Canada Waterbury Conn Ti Tal inc Carborundum Co CTS of Beine Inc Chicago Telephone of Galifornia Inc So Pasa
51. c flm 90 1 2 W HV2000 obd 2100 2199 R var comp 2 sect lin tandem ganged Series 53M 1500 and 5000 220 0681 2221 0687 1041 0687 2721 fxd comp 2200 2 10 ie 1 2 W fxd comp 100 10 1 2 W fxd comp 2700 2 10 1 2 W EB2221 EB1041 EB2721 1 4 01779 2 HP 419A DC Null Voltmeter max Model 419A Table 7 1 Parts Cont d Section VII REFERENCE hp DESIGNA TOR PART NO DESCRIPTION rr MFR PART NO 00419 61901 0683 6845 0684 2241 0684 6831 0684 2231 0683 1255 0684 3941 0683 1245 0683 3935 0684 1231 0684 3321 0687 1031 0811 1505 0698 3373 0698 3372 0698 3371 0698 3370 0698 3369 0811 1506 0686 3051 0698 3363 0698 3364 0698 3365 0698 3366 0698 3367 0698 3368 0686 1025 0681 1531 3101 0803 3101 0033 8120 0078 1251 0172 5000 0716 5000 0702 5060 0717 241 44 5060 0728 5040 4524 2040 0615 1400 0084 00419 04301 0370 0121 0370 0137 0370 0112 9000 3217 9000 3216 01779 2 Switch Assembly range fxd comp 680 5 1 4 W fxd 220 10 1 4 W fxd comp 68 kQ 10 1 4 W fxd comp 22 10 1 4 W fxd comp 1 2 5 1 4 W fxd comp 390 10 1 4 W fxd comp 120 5 1 4 W fxd comp 39 5 1 4 W fxd comp 12 10 1 4 W comp 3300 2 10 1 4 W fxd 10 10 1 2 W f
52. ce until null is reached the Model 419A s 3 uV range the output of the Assume the 419A indicates 10 pA The leakage of adjustable voltage source is very accurately the oil then be calculated matched to the reference standard E 3 23 Measuring and Recording Drift _ power supply Eleakage 419 3 24 The rear panel OUTPUT terminals provide adc voltage 0 to x 1 V proportional to meter deflection 100 V This output can be used to record the drift of a dc leakage 10 p voltage source whenthat source is compared to a very Stable reference voltage Example R 1013 Q leakage Assume that the drift of a 10 V power supply is to be observedand recorded The power supply Model 419A stable voltage source hp Model 740B and R 107 astripchart recorder hp Sanborn Model 7701A leakage are connected as shown in Figure 3 4 ADJUSTABLE VOLTAGE SOURCE AC DC AVM NULL DETECTOR DC STANDARD REFERENCE STANDARD ESSA hp 7418 DC TRANSFER STANDARD hp 735A OUTPUT Z 419A B 0994 Figure 3 3 Calibrating A DC Standard 01779 2 3 3 HP 419A Null Voltmeter max Section Model 419A STRIP CHART RECORDER hp 7701A SANBORN DRIFT DETECTOR hp 419A POWER SUPPLY TO OUTPUT TERMINALS ON REAR PANEL 419 0992 PANEL INPUT STABLE VOLTAGE SOURCE DC STANDARD AVM OUTPUT Figure 3 4 Measuring Power Supply Drift
53. d DEC 1966 01779 2 HP 419A DC Null Voltmeter max Model 419A Table of Contents List of Tables TABLE OF CONTENTS Section V 5 1 Introduction 5 3 Test Equipment 9 9 Performance Tests 5 1 Voltmeter Accuracy Test 9 9 Bucking Voltage Test 5 11 Ammeter Accuracy Test 5 13 Response Time 9 15 Superimposed AC Rejection Test 5 17 NOISE 5 19 Input Resistance Test 0 21 Repair Procedures 5 22 Cover Removal 5 24 servicing Printed Circuit Boards 5 29 Adjustment and Calibration 5 31 Mechanical Zero Adjustment 5 33 Chopper Adjustment 5 35 Electrical Zero Adjustment 5 37 Full Scale Calibration 5 39 Battery Test Calibration 5 41 Troubleshooting 5 43 No Response to Input 5 45 Positive Negativ Foldover 5 47 Excessive 15 5 49 Troubleshooting the Input At ienuaiof ex v 5 51 Replacement of Factory Selected Components Section VI CIRCUIT DIAGRAMS 6 1 Introduction 6 3 Schematic 6 5 Component Location Diagrams Section REPLACEABLE PARTS 1 1 Introduction 1 4 Ordering Information 1 6 Non Listed Parts Appendix A CODE LIST OF MANUFACTURERS Appendix B SALES AND SERVI
54. d Vertriebs GmbH Reginfriedstrasse 13 Munich 9 Tel 49 51 21 Hewlett Packard Vertriebs GmbH Beim Strohhause 26 28 Hamburg 1 Tel 24 05 51 Hewlett Packard Vertriebs GmbH Technisches Buro Herrenberger Strasse 110 Boblingen Wurttemberg Tel 6971 Hewlett Packard Vertriebs GmbH Lietzenburger Strasse 30 Berlin W 30 Tel 24 86 36 Hewlett Packard Vertriebs GmbH Achenbachstrasse 15 4 Dusseldorf 1 Tel 68 52 58 GREECE K Karayannis Klaftmonos Square Athens 124 Tel 230 301 INDIA The Scientific Instrument Co Ld 6 Bahadur Sapru Road Allahabad 1 Tel 2451 The Scientific Instrument Co Ld 240 Or Dadabhai Naoroji Road Bombay 1 Tel 26 2642 _ The Scientific Instrument Co 14 1l Esplanade East Calcutta 1 Tel 23 4129 The Scientific Instrument Co Ld 30 Mount Road Madras 1 Tel 86339 The Scientific Instrument Co 14 8 7 Ajmeri Gate Extn New Delhi 1 Tel 271053 IRAN Telecom Ltd 0 Box 1812 Teheran Tel 43850 48111 ISRAEL Electronics amp Engineering Ltd Division of Motorola Israel Ltd 16 Kremenetski Street Tel Aviv Tel 35021 ITAL Y Hewlett Packard Italiana 5 Viale Lunigiana 46 Milan Tel 69 15 84 Hewlett Packard Italiana S p A Palazzo Italia Piazza Marconi 25 Rome Eut Tel 591 2544 JAPAN Yokogawa Hewlett Packard Ltd 59 l chome Yoyogi Shibuya ku Tokyo Tel 370 2281 Yokogawa Hewlett Packard Lid 8 Umeda Kita ku
55. d met flm metal film pot potentiometer vdcw direct current working mir manufacturer p p peak to peak voltage F farad s mtg mounting 3 ppm parts per million FET field effect transistor mV millivolt s 10 volts prec precision temperature watt s fxd fixed pu micro 10 _6 coefficient long term w with GaAs gallium arsenide uV mierovolt s 10 volts stability and or tol wiv working inverse voltage GHz gigahertz 107 hertz my Mylar erance E 9 ww wirewound gd guard ed nA nanoampere s 10 R resistor i selected germanium amperes Rh rhodium at factory average ground NC normally closed rms root mean square value shown part may Ne neon rot rotary be omitted H henry ies NO normally open mercury NPO negative positive zero Se selenium standard type num Hz hertz cycle s per zero temperature co sect section s ber assigned selected second efficient Si silicon or special type REV F 8 Dupont de Nemours 01779 2 1 1 HP 419A DC Null Voltmeter max Section VII 2 00419 66502 2 1 0180 0149 0150 0093 0180 0059 0160 0161 1901 0025 2 1 thru A2CR4 A2CR5 1902 0048 A2CR6 thru 1901 0025 AZCR8 2 9 1902 0563 201 thru 1854 0039 203 A2Q4 1854 0033 A2Q5 1853 0010 A2R1 0687 1511 A2R2 0686 7515
56. del 130C Oscilloscope Strip Chart Recorder Horizontal Sensitivity 2 ms cm Vertical Sensitivity 50 mV cm Frequency Response 100 kHz Electronic Counter Counting Range 300 to 400 pps hp Model 5211 Electronic Accuracy 1 count Counter DC Voltmeter Voltage Range 30 Vdc hp Model 427A Voltmeter Accuracy 2 Resistors VOLTMETER CALIBRATOR hp 419A hp 738BR DC NULL VOLTMETER Oscilloscope 0 1 uF 20 10 Vac i Part 0170 0085 Part No 0170 0085 100 Q 0 1 1 8 W ww hp Part No 0811 0398 600 9 1 1 8 W comp 7 hp Part 0684 1031 10 kQ 0 25 1 8 W met flm hp Part No 0698 3193 100 0 25 1 8 W met flm hp Part No 0698 4057 900 0 5 1 2 W met flm hp Part No 0698 5488 1 0 1 1 8 W ww hp Part No 0811 0473 9 MQ 0 5 1 2 W met flm hp Part No 0698 5443 Figure 5 1 Voltmeter Accuracy Performance Test Setup D 0 01779 2 HP 419A DC Null Voltmeter max Model 419A Section V SECTION V MAINTENANCE 5 1 INTRODUCTION 5 2 This section contains the information necessary for maintenance of the Model 419A DC Null Voltmeter Included are performance tests repair procedures adjustment and calibration procedures and trouble shooting procedures 5 3 TEST EQUIPMENT 5 4 Thetest equipment required for maintenance of the Model 419A is listed in Table 5 1 Equipment having similar character
57. dena Calif Palo Alto Calif Santa Ana Calif Microwave Electronics Corp Duncan Electronic Inc Genera instrument Corporation Semiconductor Division Imperial Electronic Inc Melabs Inc Philadelphia Handle Co Clarostat Mig Co Nippon Electric Co Ltd Delta Semiconductor inc Thermolloy Telefunken G M B H Midland Mfg Co Sem Tech Newark Buena Park Calif Palo Allo Calif Camden J Dover N H Tokyo Japan Newport Beach Calif Dalias Texas Hannover Germany Kansas City Kansas Newbury Park Calif Calif Resistor Corp Santa Monica Calif American Components inc Conshohocken Cornell Dubilier Elec Corp 50 Plainfield Williams Mfg San Jose Calif Webster Electronics Inc Brooklyn N Y Adjustable Bushing Co N Hollywood Calif Twentieth Century Coil Spring Co The Daven Co Spruce Pine Mi a Co Computer Diode Corp De Jur Amsco Corporation Long island City 1 N Y Delco Radio Div of G M Corp Kokomo Ind Thermonetics Inc Canoga Park Calif Tranex Company Mountain View Calif Radio industries Des Plaines Curtis Instrument Inc Mt Kisco N Y E I DuPont and Co Inc Wilmington Del Eclipse Pioneer Div of Bendix Aviation Corp Thomas A Edison Industries Div of McGraw Edison Co West Orange N J Electra Manufacturing Co Kansas City Mo Electronic Tube Corp Philadelphia Pa Executive Inc New York N Y Fansteel Metallurgical
58. ed from the ac power con nector Line operation occurs automatically whenever the power cable is connected to the power connector NOTE Best isolation characteristics and freedom from ground loop prob lems results when the 419A is operated on its internal battery supply 3 7 TURN ON PROCEDURE BATTERY OPERATION NOTE Disconnect the power cable from the power receptacle for battery operation a Depress BAT TEST pushbutton if meter does not indicate within BAT limits perform battery charging procedure Paragraph 3 13 NOTE When the 419A 15 received or after a period of storage es pecially at high temperatures the batteries may require changing Erratic and inaccurate operation may result if the instrument is operated on weak batteries b Set RANGE switch to 1 V 01779 2 INSTRUCTIONS c Depress ZERO pushbutton If meter does not indicate zero perform the meter zeroadjust ments Paragraphs 5 31 thru 5 36 d Zero meteron 3 uV range with ZERO control Periodically recheck setting of ZERO control on the 3 uV range 3 8 TURN ON PROCEDURE AC LINE OPERATION a Set linevoltage two position slide switch rear panel to correct position for available line voltage DAMAGE TOINSTRUMENTMAY RESULT IF LINE VOLTAGE SWITCH IS SETINCORRECTLY b Connect ac power connector tothe line using the ac power cable supplied C Set RANGE switch to 1 V d Depress ZERO pushbutton If meter doesnot i
59. effers Electronics Division of Speer Carbon Co Du Bois Pa Allen B DuMont Labs Inc Clifton N J Maguire Industries Inc Sylvania Electric Prod Inc Greenwich Cann Electronic Tube Div Emporium Astron East Newark N J Switchcraft Inc Chicago IH Metals and Controls inc Div of Texas Instruments Inc Spencer Prods Research Products Corp Rotron Manufacturing Co Ine Vector Electronic Co Western Washer Mfr Co Los Angeles Calif Carr Fastener Co Cambridge Mass New Hampshire Ball Bearing Inc Peterborough Darlington S C Los Angeles Calif Springfield N J Red Bank N J Attleboro Mass Madison Wis Woodstock N Y Glendale Calif Pyramid Electric Co Electro Cords Co Victory Engineering Corp Bendix Corp Red Bank Div Hubbell Corp Mundelein tll Smith Herman Inc Brooklyn N Y Central Screw Co Chicago 111 Gavitt Wire and Cable Co Div of Amerace Corp Burroughs Corp Electronic Tube Div Eveready Battery Model Eng and Inc Brookfield Mass Plainfield N J New York N Y Huntington Ind Loyd Scruggs Co Festus Mo Arco Electronis Inc New York N Y A J Glesener inc San Francisco Calif Good All Electric Mfg Neb Sarkes Tarzian Inc Bloomington Ind Boontan Molding Company Beonton N J A B Boyd Co San Francisco Calif Code No 85474 85660 85911 86197 865
60. esistance of 100 to 100 MQ depending on the range selected When used as a dc null voltmeter end scale ranges from 3uV to 300 mV are provided with infinite input re sistance End scale ranges from 3Q pA to 30 nA are provided in the ammeter function with a constant 100 input resistance 4 5 When used as an ammeter circuit operation 15 identicalto the voltmeter mode of operation Current values are derived from the voltage drop across the constant 100 input resistance on the 30 pA 3 uV to 30 nA 3 mV ranges 4 6 Adcvoltagebeing measured with the Model 419A is applied to the Input Attenuator through the and INPUT terminals located onthefront panel In the dc voltmeter and ammeter modes the input is applied to the input attenuator through 51826 Inthe dc null volt meter mode the output of the Bucking Supply is applied to S1R26 in series opposition to the input dc voltage The difference between the Bucking Supply output and the input dc voltage is applied to the Input Attenuator Table 4 1 liststhe attenuationfactors provided by the Input Attenuator for all ranges 4 7 Thedcoutput of the Input Attenuator is modulated by the Modulator The Modulator is comprised of two photocells which are alternately illuminated by two neon lamps The output of the modulator is a square wave whose amplitude is proportional to the difference between the amplitudes of the input dc voltage and the feedback 4 8 The square wave o
61. eter Included are schematic and 6 5 COMPONENT LOCATION DIAGRAMS component location diagrams 6 6 The physical configuration of the 419 1 shown 6 4 The electrical configuration of the 419A is shown on the component location diagrams Each component on the schematic diagrams Individual schematics is identified by reference designation REFERENCE DESIGNATIONS PARTIAL REFERENCE DESIGNATIONS ARE SHOWN PREFIX WITH ASSEMBLY OR SUBASSEMBLY DESIGNATION S OR BOTH FOR COMPLETE DESIGNATION COMPLETE ASSEMBLY SUBASSEMBLY COMPONENT DESIGNATION 2 Q1 A2Q1 2 1 R1 A2A1R1 NONE NONE 41 J1 Assembly Reference Assembly Assembly Part Number Designation Name includes A2A1 subassembly ee not mounted on Assembly A2 Assembly 43 Pin 4 JI Destination of wire J2 Number indicates pin of 4 Plug Jack Pin may or may not gt be numbered 92 Wire Color Color code same as resistor uc c pin connector color code First number indicates base RI n WHT RED wire color second number indentifies wider strip Male standoff pin connector man N third number indicates narrower strip Eyelet or standoff terminal E g 924 denotes WHT RED YEL may or may not be numbered T 01779 2 6 1 HP 419A DC Null Voltmeter max Section 51 TOP VIEW R23 go 2 j A i
62. ewriter eraser and ensure they are making good connections d Check the transistors AC Amplifier for noise A4Q1 or Q2 most probable 5 49 TROUBLESHOOTING THE INPUT ATTENUATOR 5 50 If trouble is suspected inthe input attenuator or feedback divider proceed as follows a Rotatethe range switch through all positions several times to clean the switch contacts b Check the 90MQ resistor S1R3 for dustac cumulation clean if necessary If trouble persists carefully check the input attenuator and feedback divider resistors NOTE Parallel paths exist for several of the resistors Before placing a suspected resistor un solder one lead and check the re sistor again 9 6 Model 419A 5 51 REPLACEMENT OF FACTORY SELECTED COMPONENTS 5 52 Certain components within the Model 419A are individually selected in order to compensate for slightly varying circuit parameters These components are identifiedby anasterisk onthe schematic diagrams and a typical value is shown Thefollowing paragraphs describe the function of the factory selected com ponents and give replacement instructions 5 53 A4R26 5 54 A4R26 is factory selected to provide proper amplifier response time Response time canbe evalu ated by performing the Response Time Test Para graph 5 13 A4R26 should be replaced only if re sponse time cannot be corrected by performing the chopper adjustment procedure Paragraphs 5 3
63. heater Q transistor bulb photocell etc C capacitor jack QCR transistor diode wW cable Ck diode K relay R resistor x socket DL delay line L inductor RT thermistor XDS lampholder DS lamp meter 5 switch fuseholder mise electronic part MC microcircuit T transformer Z network ABBREVIATIONS Ag silver ID inside diameter ns nanosecond s 10 51 slide Al aluminum impg impregnated seconds SPDT single pole double ampere 8 ined incandescent nsr not separately replace throw gold ins insulation ed able SPST single pole single kQ kilohm s 10 ohms 2 ohm s _ ee cereale 8 order by description lt tantalum ius coef coefficient kHz kilohertz 10 hertz OD soale ide diameter TC temperature coefficient com common TiO titanium dioxide comp composition L inductor _ k conn connection lin linear taper pes iod eium tog toggle dep deposited log logarithmic taper pe tol tolerance DPDT double pole double 3 pF picofarad 101 T m mili 10 TSTR transistor throw 3 farads DPST double pole single mA milliampere s 10 piv peak inverse voltage V volt s throw amperes 6 part of vacw alternating current MHz megahertz 10 hertz pos position working voltage elect electrolytic megohm s 1076 ohms poly polystyrene var variable encap encapsulate
64. iagrams 01779 2 0 6 5 HP 419A DC Null Voltmeter max Model 419A Section VII SECTION VII REPLACEABLE 7 1 INTRODUCTION 7 2 This section contains information for ordering replacement parts Table 7 1 lists parts in alpha meric order of their reference designators and indi cates thedescription hp part number of each part together with any applicable notes and provides the following a Total quantity used in the instrument TQ column Thetotal quantity of a part is given the first time the part number appears b Description ofthe part See list of abbrevia tions below c Typical manufacturer of the part in a five digit code See Appendix Afor list of manu facturers d Manufacturer s part number PARTS 1 3 Miscellaneous parts are listed at the end of Table 7 1 7 4 ORDERING INFORMATION 1 5 To obtain replacement parts address order or inquiry to your local Hewlett Packard Field Office See Appendix B for list of office locations Identify parts by their Hewlett Packard partnumbers Include instrument model and serial numbers 7 6 NON LISTED PARTS 7 7 obtain a part that is not listed include a Instrument model number b Instrument serial number c Description of the part d Function and location of the part DESIGNATORS A assembly F fuse MP mechanical part TC thermocouple a motor FL filter P plug yacuum tube neon B battery HR
65. ing sheet should be replaced using the part number given in the manual Instrument Serial Prefix Make Manual Changes Instrument Serial Prefix Make Manual Changes 532 0400 and below CHANGE 1 Figures 6 1 and 6 3 Substitute Figures C 1 and C 2 for the ones in Figures 6 1 and 6 3 Table 7 1 Change all A4 reference designators to A1 Change hp Part No of Al to 00419 66504 Change 1 13 to hp Part 0180 0022 C fxd elect 3 9 uF 35 vdcw Delete A1C14 thru 1 1 Change thru AICR16 to AICRI thru A1CR14 Change AIR38 to hp Part No 0686 3055 R fxd comp 3 5 1 2 W Change A1R41 thru A1R44 to hp Part No 2100 1410 R var lin 20 kQ 30 1 8 W Change A1R48 to hp Part No 0687 6821 R fxd comp 6 8 kQ 10 1 2 W Delete A1R50 and AIR51 Add C1 hp Part No 0180 0283 fxd Al elect 60 uF 75 10 10 vdew CHANGE 2 Table 7 1 Change J2 to hp Part No 1510 0010 Change to hp Part No 1510 0011 Change J5 to hp Part No 1510 0026 Change J6 to hp Part No 1510 0027 CHANGE 3 Figure 6 3 Change A1R26 10 K to AIR26 22 K Move A1R26 between A CR3 and 4 and Q8 Base Delete C10 3 7 uF in emitter of 012 and Q13 Add C10 20 uF between A1 13 Short R40 100 Q in base of A1Q10 Add R40 39 kQ between A1C13 and A1R39 Table 7 1 Change A1C10 to C fxd Al elect 20 pF 75 10 25 vdew hp Part 0180 0045 Change A1R26 to R fxd 22
66. istics may be substituted for the equipment listed 5 5 PERFORMANCE TESTS 0 6 The performance tests presented in this section are front panel procedures designed to compare the Model 419A with its published specifications Table 1 1 These tests may be incorporated in periodic main tenance post repair and incoming quality control in spection These tests should be conducted before any attempt is made at instrument calibration 9 1 VOLTMETER ACCURACY TEST 5 8 Thevoltmeteraccuracy performance test setup is illustrated in Figure 5 1 voltmeter calibrator hp Model 738BR a 100 Q resistor hp Part No 0811 0398 anda 1 MQ resistor hp Part No 0811 0473 are required for this test a Connect test setup illustrated in Figure 5 1 b Make control settings indicated in step 1 of Table 5 2 i Model 419A reading is not within tolerances listed perform Full Scale Cali bration procedure Paragraph 5 37 Repeat stepbfor remaining steps Table 5 2 9 9 BUCKING VOLTAGE TEST 5 10 No external test equipment is required for the bucking voltage performance test a Depress 419A READ NULL pushbutton set RANGE to 300 mV b Rotate NULL control fully clockwise and then fully counterclockwise if 419A meter does not peg in negative and positive direction respectively replace 5 Table 5 2 Accuracy Performance Test Supplemental Data VOLTMETER CALIBRATOR DC OUTPUT 1 2 3 4 6 7 8
67. larcid Corp Precision Thermometer and Inst Co Raytheon Company Englewood Calo Skokie UN Cambridge Mass Philadelphia Pa Lexington Mass Rowan Controller Co Baltimore Md Ward Leonard Electric Mt Vernon N Y Shallcross Mfg Co Selma Simpson Electric Co Chicago 111 Sonotone Corp Etmsford Sorenson amp Co Inc Spaulding Fibre Co Inc Sprague Electric Telex Inc Thomas amp Betts Co Tripplett Electrical Inc Union Switch and Signal Div of Westinghouse Air Brake Universal Electric Co Ward Leonatd Electric Ca Mt Vernon N Y Western Electric Co Inc New York N Y Weston Inst Div of Daystrom Inc Newark N J Wittek Manufacturing Co Chicago 23 Ill Wollensak Optical Co Allen Mfg Co Allied Control Co Inc Allmeta Screw Prod Co inc Garden City M Y So Norwalk Conn Tonawanda N Y North Adams Mass St Minn Elizabeth 1 N d Bluffton Ohio Swissvale Pa Owosso Mich Hartford Conn Mew York N Y Atlantic India Rubber Works Inc Chicago HR Amperite Co Inc New York N Y Beiden Mfg Co Chicago 111 Bird Electronic Corp Birnbach Radio Co Boston Gear Works Div of Cleveland New York N Y Murray of Texas Quincy Mass Bud Radio Inc Cleveland Ohio Fastener Corp Paramus Allen D Cardwe l Electronic Prod Carp Plaiaville Conn Bussmann Fuse Div of McGraw Edison
68. loy Products Elizabeth N J Times Facsimile Corp New York N Y Electronic Industries Association Any brand tube meeting EIA standards Washington D C Unimax Switch Div of W L Maxson Corp United Transformer Corp Oxford Electric Corp Bourns Laboratories Inc Acro Div of Robertshaw Fulton Controls Co Aff Star Products Inc Avery Adhesive Label Corp Hammerlund Co Inc Stevens Arnold Co Inc Intemational Instruments Inc Wallingford Conn New York N Y Chicago lil Riverside Calif Columbus 16 Ohio Getiance Chie Monrovia Calif New York N Y Boston Mass New Haven Conn LaGrange Venice Calif Norwalk Conn Grayhill Co Triad Transformer Corp Winchester Electronics Co inc FSC Handbook Supplements 4 1 Dated DECEMBER 1954 H4 2 Dated MARCH 1962 Appendix Code 81349 81415 81453 81483 81541 81860 82042 82142 82170 82209 82219 82376 82389 82647 82866 82877 82843 83053 82058 83086 83125 83148 83186 83296 83115 83330 83385 83501 83594 83740 83777 83821 84171 84396 84411 84970 85454 85471 Manufacturer Military Specification Wilkor Products Inc Cleveland Ohio Raytheon Co industrial Components Div Industr Tube Operations Newton Mass Internationa Rectifier Corp Segundo Calit The Airpax Products Co Cambridge Mass Barry Controls Inc Watertown Mass Carter Parts Co Skokie J
69. ltmeter max WI 4 9A D 0974 FISE S p 1 8 e 52 15 JI O 53 i5 1 1250 52 FUNCTION SWITCH rast vM ser READ OFF TEST ZERO NULL NULL 0 4 PHOTO CHOPPER ASSEMBLY 00419 63001 Al mee eee is NEON SUBASSEMBLY 1990 0214 NOTE 8 R2 RI CR2 CRI CI so oe m COPYRIGHT 1966 BY HEWLETT PACKARD COMPANY POWER SUPPLY AND NEON DRIVER ASSEMBLY 00419 66502 r UI ibt oo VV ZZ om E mn ad 2 m C URREN T ADJ R 20K ee ee eee eee ee ee en eee A ee D o v LL m AA m s ee ee gum rm EE B HP 419A DC Null Voltmeter max Model 4197 Se eee P POWER SUPPLY 2 22 Y o RC 29 NEON DRIVER 18V R6 4TK W 01779 2 Model 419A Section VI SSS oe ee ee ee ee eee Ee SSEMBLY 00419 66502 POWER SUPPLY RI 50 CR2 23 TO AA T Re 750 TAI P O 82 yi 2 NS 7 5 NEON DRIVER FREQ ADJ E gt eee ee Figure 6 4 Power Supply and Neon Driver Schematic and Component Location D
70. ly down scale from zero then reverse directionto obtainfine adjustment h Depress READ NULL pushbutton Read value of input voltage on meter 3 10 DC CURRENT MEASUREMENTS a Turnonandzero the Model 419A according to the steps in Paragraph 3 7 Battery Operation or 3 8 Line Operation Allow at least ten minutes warmup time if low value currents below 10 nA are to be measured b Connecttest leadsto and INPUT terminals c Set RANGE to range nearest above current tobe measured indoubt start on 300 nA position and reduce as necessary d Connect test leads in series with current to be measured e Depress VM AM pushbutton Read value of in put current on meter scale 3 11 Amplifier Output 3 12 The rear panel OUTPUT terminals provide a dc voltage which is proportionalto meter deflection The LEVEL control adjusts the maximum value of output voltage Withthe LEVEL control turnedfully the voltage varies from 010 1 Vdc into a 1 load Polarity of the voltage depends upon polarity of the meter deflection 3 2 Model 419A 3 13 Battery Charging Procedure 3 14 The batteries are automatically trickle charged whenever the Model 419A is connected to an ac power lineandthe ZERO VM AM SETNULLorREADNULL pushbutton is depressed Theinstrument may be used whiletrickle charging occurs except when the batteries have been almost completely discharged Under this condition the Model 419A may not
71. me Calif Los Angeles 45 Calif Rubber Eng amp Development D Manufacturing Co Cooltron Contro of Elgin Watch Ca California Eastern Lab FSC Handbook Supplements 4 1 Dated DECEMBER 1964 H4 2 Dated MARCH 1962 Model 419A Appendix B SALES AND SERVICE OFFICES ALABAMA Huntsville 35802 2003 Byrd Spring Rd S W 205 881 4591 TWX 510 579 2204 ALASKA Bellevue Wash 98004 11656 N E 8th Street 206 454 3971 TWX 910 443 2303 ARIZONA Scottsdale 85251 3009 No Scottsdale Rd 602 945 7601 TWX 602 949 0111 Tucson 85716 232 So Tucson Blvd 602 523 2564 TWX 602 792 2759 CALIFORNIA North Hollywood 91604 3939 Lankershim Blvd 213 877 1282 and 766 3811 TWX 910 499 2170 Sacramento 95821 259 Carlsbad Ave 916 482 1463 TWX 916 444 8683 san Diego 92106 1055 Shafter Street 714 223 8103 TWX 714 276 4263 Palo Alto 94303 1101 Embarcadero Rd 415 327 6500 TWX 910 373 1280 COLORADO Englewood 80110 7965 East Prentice 303 771 3455 TWX 910 935 0705 CONNECTICUT Middletown 06457 589 Saybrook Rd 203 346 6611 TWX 710 428 2036 FLORIDA Miami 33125 2907 Northwest 7th St 305 635 646 Orlando 32803 62 Commonwealth Ave 305 425 5541 TWX 305 841 2568 St Petersburg 33708 410 150th Ave Madeira Beach 813 391 0211 and 391 1829 TWX 813 391 0666 GEORGIA 5 66 Atlanta 30305 3110 Maple Drive 404
72. ndicate zero perform meter zeroadjustments Paragraphs 5 31 thru 5 36 e Zero meter 3 uV range with ZERO control Periodically recheck setting of zero control the 3 uV range 3 9 DC VOLTAGE MEASUREMENTS a Turnon the Model 419A andzero it according to the steps in Paragraph 3 7 battery operation or Paragraph 3 8 Line Operation Allow at least ten minutes warmuptime if low voltages below 1 mV are to be measured b Connecttest leads to and INPUT terminals See Table 1 3 fora list of test leads available Set RANGE switch to range nearest above input voltage Ifindoubt start 1000 V range and downrange as necessary TO PREVENT DAMAGE TO THE MODEL 419A DO NOT EXCEED THE FOLLOWING OVERLOAD LIMITS RANGE MAXIMUM INPUT VOLTAGE 90 Vdc 900 1200 Vdc 3 to 3 mV 10 mV to 300 mV 1 V to 1000 V HP 419A DC Null Voltmeter max Section d Connect test leads to voltage to be measured DO NOT FLOAT MODEL 419A IN PUT TERMINAL MORE THAN 500 VDC FROM GROUND 4 e Depress VM AM pushbutton Read value of input voltage on meter scale NOTE If input voltage is 300 mV or less infinite input im pedance may be ob tained by proceeding with steps f thru h f Depress SET NULL pushbutton Rotate NULL control until meter indicates exactly zero NOTE NULL control gives both coarse and fineadjustment Rotate con trol until pointer is slight
73. nment and neon selection are cri tical When trouble is isolated to the neon subassembly the complete subassembly should be changed rather than replacing the defective neons a Remove the top and side cover on the meter side of the instrument b Disconnect the neon subassembly leads from pins on A2 board Note location for recon necting the new leads Maneuver subassembly cable through the grommet on the inner shield c Removethe two photochopper assembly mount ing screws and remove neon subassembly d Install new neon subassembly Note that the rubbergrommet on the subassembly is offset toward the top of the instrument e Route the neon subassembly cable through the inner shield and reconnect the cable to the 2 board f Replace the side cover and recalibrate the Model 419A as outlined in Paragraph 5 29 5 29 ADJUSTMENT AND CALIBRATION 5 30 Thefollowing isa complete adjustment and cali bration procedure for the Model419A These proce 5 4 Model 419A dures shouldbe conducted only if ithas been previously established by Performance Tests Paragraphs 5 5 to 5 20 that the Model 419A is out of adjustment 5 31 MECHANICAL ZERO ADJUSTMENT 5 32 The mechanical zero adjustment is located on the instrument front panel the meter pointer does not indicate zero when the instrument power hasbeen off for at least one minute mechanically zero the meter following the procedure outlined below a Turn inst
74. nnect 419A to Point adjust A4R42 10 pV for full scale deflection on 10 uV range NOTE Remove resistive attenuatorbefore performing steps e and f e Set Voltmeter Calibrator for 1 mV output connect 419A to Point B adjust A4R43 1 MV for full scale deflection on 1 mV range 01779 2 Section V f Set Voltmeter Calibrator for 1 V output con nect 419A to Point B adjust A4R44 1 V for full scale deflection on 1 V range 5 39 BATTERY TEST CALIBRATION 5 40 A DC Voltmeter hp Model 427A is required for the battery test calibration NOTE Batteries must be fully charged be fore performingthis procedure See Paragraph 3 13 a Remove 419A top cover and shield b Connect DC Voltmeter across BT1 thru If DC Voltmeter indicates less than 26 V re charge battery power supply in accordance with Paragraph 3 13 If DC Voltmeter indi cates at least 26 V proceed to step c c Depress Model 419A BAT TEST Pushbutton adjust A4R25 BAT TEST CAL for Model 419A Meter reading 0 3 scale equal to DC Volt meter ge in step b QN VS oT 5 41 TROUBLESHOOTING 5 42 This section contains information designed to assist in the isolation of malfunctions These checks should be undertaken only after it hasbeen established thatthe trouble cannotbe eliminated by the Adjustment and Calibration Procedures Paragraph 5 29 NOTE The 419A operates erratically when the charge on the batteries is mar ginal
75. nts used appear at the bottom of each page Alphabetical codes Code No 00000 00136 00213 00334 00335 00373 00656 00779 00781 00815 00853 00866 00891 01121 01255 0128 1 01235 01349 01551 01589 01930 01961 982114 22286 02660 02735 02771 02777 03508 03705 03797 03877 03888 03954 04009 04013 04062 04222 04298 04394 04404 04651 04713 04732 04773 04777 04796 14811 04870 05005 05277 05347 03593 05616 05624 05728 05729 05783 05820 06004 05175 06402 06475 06540 05555 06751 06812 07088 Manufacturer Address U S A Common McCoy Electronics Sage Electronics Corp Any supplier af U S Mount Holly Springs Rochester N Y Humidail Co Colton Calif Westrex Corp New York N Y Garlock Packing Co Electronic Products Div Camden N J Aerovox Corp New Bedford Mass Amp Inc Harrisburg Pa Aircraft Radio Corp Boonton 1 Northern Engineering Laboratories Inc Burlington Wis Sangamo Electric Company rdil Division Capacitors Goe Engineering Co Car E Hoimes Corp Allen Bradiey Co Litton Industries Inc TRW Semiconductors Inc Texas Instruments Inc Transistor Products Div The Alliance Mfg Chassi Trak Corp Pacific Relays Inc Amerock Corp Pulse Engineering Co Ferraxcube Corp af America Cole Mfg Co Palo Aito Calif Amphenol Borg Electronics Corp Chicago IH Radio Carp of America Semiconduc
76. o CR2 CRI 100 D D Vj 4 EA Je 1 M 419A J 0963 COPYRIGHT i966 BY HEWLETT PACKARD COMPANY HP 419A DC Null Voltmeter max gt gt _ _ emery gt rem oer TER AMPLIFIER ASSEMBLY 00419 66504 3 TIBV R2 78 DEMODULATOR 005V ps2 RIA hg 20K 7 R13 RI2 56K CR CRI 2V 12 13V 13 5 ea FROM FROM Se en 82 23 HP 419A DC Null Voltmeter max TEST 13V CAL 2 R46 390K R45 500K Model 419A ra 1 1 La EN 4 r 1 L_ Section VI rcu QU TPUT CRO CRIO ema Hus ad 24 CI5 f 210 J es tL cis 0 5 39 R50 22 1OK 19 R47 R51 CIO IBK 2200 E 4 7 CRA 22 i 1 JS 6 R4 RANGE Pus 250K SCR 2 68K id R42 20 RANGE 250K SIRS 9 140K D 1812 51814 i 5 E SIRIS ey 14K SIRIG LLL sez lt 250K 14005 SIRIB 9 ee Cr 1 1 D 13V 13 2 e 2 R44 250K 3 o 15 17 a ee 9 a amp FROM FROM 2 2 52 2
77. of end scale 1 pA GENERAL 100 mV to 300 mV ranges 10 infinite when nulled 1 volt to 1000 volt ranges 100 Internal Bucking Voltage 120 end scale 3 through 300 mV range Overload Voltages 50 Vdc max 3 uV to 3 mV ranges 500 Vdc max 10 mV to 300 mV ranges 1200 Vdc max on 1 volt range and above Response Time 95 of final reading within 3 sec on the 3 uV range 95 of final reading within 1 sec on the 10 uV to 1000 V ranges Superimposed AC Rejection Ac voltages 60 Hz and above 80 db greater than end scale affects reading less than 2 Peak ac voltage not to ex ceed max overload voltage Drift lt 0 5 pu V day after 30 minutes warmup lt 0 05 uL V 9C from 0 to 50 C Noise 0 3 LV peak to peak Overload Recovery Time Meter indicates within 3 seconds for a 10 overload Input Terminals Positive and negative terminals are solid copper gold flashed Input Isolation gt 1019 ohms shunted by 250 pF May be operated up to 500 Vdc or 350 Vac rms above ground Operating Temperature 00 to 500 Storage Temperature 40 to 60 Peak to peak noise is less than 0 3 uV 95 of the time since the noise amplitude approximates a Gaussian distribution where the standard de viation which is also the rms value 0 075 Power Source 4 internal rechargeable batteries furnished Thir
78. omp 47 ohms 10 1 2 w Change A2R8 A2R9 to hp Part No 0687 4701 R fxd comp 4 ohms 10 1 2 w Change A2R10 to hp Part No 0687 1511 R fxd comp 150 ohms 10 l 2w Change A2R11 to hp Part No 0687 3341 fxd comp 330 ohms 10 1 2 w Change A2R12 to hp Part No 2100 0227 var ww 20 ohms 10 1 1 2 w Change 2 1 to hp Part No 9100 0172 Transformer power Change A2T2 to hp Part No 9100 1314 Transformer neon driver fxd comp 68 ohms fxd comp 27 ohms 01779 2 HP 419A DC Null Voltmeter max Figure 1 Model 419A Component Location Diagram Serials Prefixed 514 532 646 Part of Figure C2 Al Amplifier 00419 66501 Serials Prefixed 514 532 646 HP 419A DC Null Voltmeter max NOTES 1 PARTIAL REFERENCE DESIGNATIONS ARE SHOWN PREFIX WITH ASSEMBLY OR SUB ASSEMBLY DESIGNATION S OR BOTH FOR COMPLETE DESIGNATION 5 COMPONENT VALUES ARE SHOWN AS FOLLOWS UNLESS OTHERWISE NOTED F RESISTANCE IN OHMS RANGE CAPACITANCE IN MICROFARADS 3 MILLIVOLTS 19 2 9 Se FUNCTION SWITCH 3 DENOTES ASSEMBLY 4 7m 3 00 ww IO 2 3 4 5 6 RAT DENOTES DC FEEDBACK PATH o Fast SET READ 53 500 p di 5 DENOTES AC FEEDBACK PATH 6 qno 3 15 6 DENOTES FRONT PANEL MARKING 7 3 50 i4 1 o Roc DENOTES REAR PANEL MARKING 2m IO 15 Umm ic 8 9
79. omp 1000 10 1 2 W 01121 EB1021 A4R25 A4R26 See Paragraph 9 53 A4R27 0687 1051 fxd comp 1 MQ 10 1 2 W 01121 1051 A4R28 0687 2231 fxd comp 22 10 1 2 W 01121 2231 01179 2 7 3 HP 419A DC Null Voltmeter max Section Table 7 1 Replaceable Parts Cont d Model 419A REFERENCE hp DESIGNATOR PART NO ace DESCRIPTION MFR MFR PART NO A4R29 0681 2221 A4R30 0687 4741 A4R31 thru 0687 2241 fxd comp 2200 Q 10 1 2 W fxd comp 470 10 1 2 W fxd comp 220 10 1 2 W 2221 EB4741 EB2241 A4R33 A4R34 thru 0687 2221 A4R36 S wg EB2221 fxd comp 2200 Q 10 1 2 W fxd comp 100 10 1 2 W A4R37 0687 1041 R EB1041 A4R38 0687 3951 fxd comp 3 9 10 1 2 W EB3951 A4R39 0687 1031 fxd comp 10 10 1 2 W 1031 A4R40 0687 1011 R fxd comp 100 2 10 1 2 W EB1011 A4R41 thru 2100 1795 var comp lin 250 20 1 8 W QS 200 A4R44 A4R45 2100 1470 A4R46 0687 3941 A4R47 A4R48 0687 6831 A4R49 0687 2221 var lin 500 30 1 10 W fxd comp 390 10 1 2 W See Paragraph 5 55 fxd comp 68 10 1 2 W fxd comp 2200 2 10 1 2 W XQS 200 EB3941 EB 6831 EB2221 A4R50 0687 1031 A4R51 0687 2221 fxd comp 10 10 1 2 W fxd comp 2200 Q 10 1 2 W EB1031 EB2221 1 thru BT4 1420 0015 Battery rechargeable nickel cadmium 5
80. or Dept Ultronix Inc Miumitronic Engineering Co Cosmo Plastic c o Electrical Spec Barber Colman Co Tiffen Optical Ca Reslyn Heights Long island N Y Metropolitan Telecommunications Corp Melro Division Brooklyn N Y Stewart Engineering Co Santa Cruz Calif Wakefield Engineering Inc Wakefield Mass The Bassick Co Bridgeport Conn Bausch and Lomb Optical Co Rochester E T 4 Products Co of America Chicago 111 Western Devices Jac Inglewood Calif Amatom Electronic a Hatdware Co Inc New Rochelle N Y Beede Electrical Instrument Co Inc Penacook Semcor Division ol Nuclear Carp of America Phoenix Arizona Torrington Mfg Co West Div Van Nuys Calif Kelvin Electric Co Van Nuys Calif Youngwood Pa Sunnyvale Calif Cleveiand Ohio Rockford HH San Mateo Cade No 07115 07126 07137 07138 07149 07233 07261 07261 07322 07387 07700 07919 07933 07965 07280 08145 08289 08358 08717 08718 08792 08984 09026 09134 09145 99250 09569 09664 10214 10411 10646 11236 1123 11312 11534 i 1171 11870 12136 12697 12859 12930 13103 13356 13835 14099 14193 14298 14685 14360 15203 15291 18772 15909 15037 15352 16688 16758 17103 1747 8486 18583 18873 19315 18500 19701 20183 21226 21520 21335 21954 24446 24455 Manufacturer Address Corning Glass Works Electroni
81. owingit to start conducting As Q3 conducts a negative going signal is applied tothe base of Q2 holding it cut off and a positive going signal is appliedto the base of Q3 Q3 continuesto conduct causing a positive output tobe coupled to the neon cir cuit This will continue until T2 becomes saturated and starts the cycle over again 4 42 The output of the oscillator is coupled through T2 to the neon circuit When an input is applied to the circuit dueto inherent resistance characteristics either DS1 or DS2 willlight depending upon which has the least resistance 4 43 Assume that DS1 lights when the input is applied to T2 Capacitor C1 charges until the oscillator switches the input and DS1 goes off When the os cillator switches again the charge insures that DS2 fires and DS1 stays off This cycle continues with DS1 and the DS2 firing as long as there is an output from the oscillator CR1 and CR2 prevent the capacitor from discharging through R1 and R2 4 3 HP 419A DC Null Voltmeter max Section V Model 419A Table 5 1 Test Equipment Required INSTRUMENT TYPE REQUIRED CHARACTERISTICS RECOMMENDED MODEL Voltmeter Calibrator DC Voltage Range 0 3 mV to 300 V hp Model 738BR Voltmeter Accuracy 0 2 Calibrator Voltage Range 1 Vdc Sanborn Model 7701A Speed 50 mm sec Strip Chart Recorder Frequency Response 5 Hz Oscillator Output Freq 60 Hz hp Model 208A Oscillator Output Voltage 0 5 V rms hp Mo
82. rument power off disconnect input signal remove output cable and allow one minute for meter pointer to stabilize b Rotate zero adjustment CW until pointer is to left of zero moving upscale Continueuntil pointer isatzero If pointer overshoots zero repeat operation c When the pointer is exactly at zero rotate zero adjustment slightly CCW to free it If the meter pointer moves tothe left during this step repeat steps b and c 5 33 CHOPPER ADJUSTMENT 5 34 AnOscilloscope hp Model 130C and an Elec tronic Counter hp Model 5211A are requiredfor the chopper adjustment NOTE If Serial Prefix of instrument is 514 refer to Appendix C for chopper ad justment information a Remove 419A top cover and shield b Connect Oscilloscope and Electronic Counter to A2T P2 SetOscilloscope for 2 ms cm horizontal sen sitivity and 50 mV cm vertical sensitivity d Adjust A2R9 FREQ for Electronic Counter indication of 320 to 340 This corresponds to chopper rate of 160 170 pps as Electronic Counter also counts smaller pulses Adjust A2R5 NEON CURRENT for waveform amp litude of 140 to 160 mV Figure 5 4 shows the chopper waveform NOTE If the Neon Waveform is unstable an intermittent neon bulb is indicated See Paragraph 5 27 for replacement information If correct waveform is obtained and response time is still not withinlimits of Paragraph 5 13 AAR26 will have tobe reselected If response
83. s n a T E yY f 1 a 77 22 4 AS m L 4 zl 4lgA A 0976 PE 7L wt To 2 d PARCO HERE i Model 419A S BOTTOM VIEW Figure 6 2 Range Switch 1 Component Location Diagram HP 419A DC Null Voltmeter max 01779 1 GRN BLK Iv BAT TEST 3 V OHV HMV ZERO CAL ane eL Im R8 RiI E C3 Ri2 R29 CRE QC R20 OS 3 2 Em cR8 R5 R RmR25 R27 CRI2 cCRIi 7 R6 RIS e R34 CRIZ R46 CRs R32 CRl4 5 A Logo R3 R48 9 50 R33 V R5 u di R20 6 R40 R30 R 8 T R2 RB Ree R36 capo R37 e CIA R49 Cio R47 1 ENEN LN ESIN CNN XN 22 a a 4 Part 00419 66504 Je V Y FUNCTION SWITCH 14 P E U D READ NULE 4k8 B iDOI SET NULL VIEW EA Lod a ENEE Ege a wy A BA READ SET oc BAT NULL NULL ER TEST 9 FAST
84. sistor f Set Model 419A RANGE to 10 mV set volt meter calibrator output to 10 mV 01 V Model 419A should read 9 09 mV which veri fiesan input resistance of 1 on the 10 mV range h Replace the 100 resistor with a 1 MQ re sistor 01779 2 i Set Model 419A RANGE to 100 mV set volt meter calibrator output to 100 mV 1 V j Model 419A should read 90 9 mV which veri fies an input resistance of 10 on the 100 mV range k Replace the 1 MQ resistor with a 10 MQ re sistor 1 Set Model 419A RANGE to 1 V set voltmeter calibrator output to 1 V m Model 419A should read 0 909 V which veri fies an input resistance of 100 on the 1V range 5 21 REPAIR PROCEDURES 5 22 COVER REMOVAL 5 23 When it is necessary to repair or adjust the Model 419A one or more covers will have to be re moved Refertothefollowing stepsfor cover removal procedure a TOP COVER Removetopcover screws slide cover to rear and lift to remove b SIDE COVERS Remove four screws from side cover lift to remove c BOTTOM COVER Remove bottom cover screwsatrear of cover Slide cover to rear and remove 5 24 SERVICING PRINTED CIRCUIT BOARDS 5 25 The Model 419A has two etched circuit boards Use caution when removing to avoid damaging mounted components The assembly and hp part number are etched on the interior of the circuit boardto identify them Refer to Section VII for parts replace ment and
85. tor and Materials Div Somerville N J Vocaline of America Inc Old Saybrook Conn Hopkins Engineering Co San Fernando Calif G E Semiconductor Products Dept Syracuse Apex Machine amp Tool Co Dayton Ohio Eidema Corp E Monte Calif Transitron Electronic Corp Waketield Mass Pyrofiim Resistor Co Morristown N J Air Marine Motors Ine Los Angeles Calif Arrow Hart and Hegeman Elect Co Hartford Conn Lambertville J New York N Y Myrtle Beach S C Marion 11 Los Angeles Calif Los Angeles Calif Milwaukee Wis Beverly Hiils Calif Lawndale Calif Dallas Texas Alliance Ohio Indianapolis Ind Van Nuys Calif Rockford ill Santa Clara Calif Saugerties N Y Taurus Elmenco Products Co Hi Q Division of Aerovox Elgin National Watch Co Electronics Division Burbank Calif Precision Paper Tube Chisago Dymec Division ol Hewlett Packard Co Palo Alto Calil Sylvania Electric Prods inc Electronic Tube Div Mountain View Calif Motorola tnc Semiconductor Prod Div Phoenix Arizona Filtron Co inc Western Div Culver City Calif Automatic Electric Co Northlake 11 Automatic Electric Sales Corp Northlake Hi Sequoia Wire amp Cable Co Redwood City Calif Precision Coif Spring Co Monte Calif P Motor Company Chicago 44 Twentieth Century Plastics Inc Los Angeles Calif Westinghouse Electric Corp Semi Conduct
86. tor is a photo conductive chopper Itconsists ofa neon oscillatorwith two neon bulbs and four photocells mounted in one assembly The photocells have an extremely high resistance when not illuminated and a very low resistance when il luminated 4 21 Assume that A3V1 is illuminated and A3V2 is not The resistance of A3V2 willbe many times greater thanthe resistance of A3V1 The voltage across A3V2 input voltage willbe applied through A3C4 tothe base of 01 The oscillator willthen switch off the bulb il luminating A3V1 and switch onabulb which illuminates 2 1 now has the greatest resistance and A3V2is a virtual short to the feedback which is coupled to Ql The modulator provides a square wave output proportionalto the differencebetween the dc input and dc feedback signals square wave frequency will depend uponthe switching frequency of the neon oscil lator 4 22 The demodulator is operated by the neon oscil lator in the same manner It provides a dc output proportionalto the amplitude ofthe square wave input 4 23 AC AMPLIFIER 4 24 Amplification of the square wave outputfrom the modulator is provided by a six stage direct coupled amplifier Dcfeedbackfrom the base of Q4to the base 4 2 Model 419A of Q1 provides bias stabilization Ac feedback from the emitter of Q3 to the emitter of Q1 is used to vary thegainof Qlthru Q3 Thisisaccomplishedby varying the amount of feedback to Q1 due to the position
87. ty hour operation per recharge The 419A may be operated during rechargefrom ac line 115 or 230 V 10 50 to 1000 Hz ap proximately 3 watts Dimensions Standard hp 1 2 module 6 high 7 3 4 wide 8 deep 152 x 197 x 203 mm 1 0 01779 2 AMPLIFIER Gain 110db maximum at recorder output terminals Gain depends on range HP 419A DC Null Voltmeter max Model 419A Section SECTION 1 GENERAL 1 1 INFRODUCTION 1 2 This section contains general information about the Model 419A DC Null Voltmeter Figure 1 1 In cluded are Specifications Description and Purpose Instrument Identification Accessory Equipment Sup plied and Accessory Equipment Available 1 3 SPECIFICATIONS 1 4 Table 1 1 contains the specifications for the Model 419A 1 5 DESCRIPTION AND PURPOSE 1 6 The Model 419A is housed ina standard hp 1 2 module case Arechargeablebattery power sup ply allows operation independent of ac line Range and function switching is accomplished by front panel controls 1 7 The Model 419A provides 18 end scale voltage ranges 1 3 10 sequence from 3 microvoltsto 1000 volts The Model 419 also provides 7 end scale current ranges from 30 picoampsto 30 nanoamps An internal bucking supply allows voltages up to 300 millivolts tobe measured with infinite input im pedance The input impedance for the higher ranges is 100 MQ 1 8 Recorder output terminals
88. utput of the modulator is amp lified by the AC Amplifier The AC Amplifier is a six stage high gain amplifier Its output is applied to the Demodulator The Demodulator output is a dc level whose amplitude is proportionalto the amplitude of the square wave The Demodulator output is applied to the DC Amplifier a three stage voltage and power amplifier 4 9 The forward gain provided by the AC and DC Amplifiersfor each range is listed in Table 4 1 output of the DC Amplifier approximately 1 Vdc for end scale meter deflection is applied to M1 and is also available at the OUTPUT and terminals 4 10 The Feedback Control circuit is ganged to the Input Attenuator by the RANGE switch S1 feed back providedby the Feedback Control circuit is listed in Table 4 1 Algebraic addition of attenuation factor forward gain and feedback gives the closed loop gain The closed loop gain provides 18 end scale ranges in 10 dB steps 4 11 DETAILED DESCRIPTION 4 12 BUCKING SUPPLY See Figure 6 3 4 13 Dc input voltages up to 200mV may be measured in either the dc voltmeter mode or the null voltmeter Table 4 1 Model 419A Attenuation and Gain Characteristics RANGE ATTENUATION FACTOR FORWARD GAIN CLOSED LOOP GAIN 3 30 pA 10 uV 100 pA 30 uV 300 pA 100 1000 pA 300 uV 3000 pA 1mV 10nA 3mV 30nA 10 mV HP 419A DC Null Voltmeter max Section IV mode In the
89. voltages below 300 mV when SET NULL pushbutton is depressed Selects one of full scale voltage or current ranges Provides variable control 0 to 1 V full scale of and recorder OUTPUT Provide for connection of external recorder Enables selection of either 115 or 230 Vac line voltage Accepts fuse for protection of primary power circuits Accepts 3 pin power cord Front and Rear Panel Controls Indicators and Connectors 01779 2 HP 419A DC Null Voltmeter max Model 419A Section SECTION Ill OPERATING 3 1 INTRODUCTION 3 2 The Model 419A functions asa dc voltmeter with full end scale ranges from 3 uV to 1000 V An in ternal bucking supply allows essentially infinite input impedance tobe achieved onthe 3 uV to 300 mV ranges The Model 419A can also measure low level de cur rents with full end scale ranges from 30 pA to 30 nA This section describes the operating procedures and presents some applications for the Model 419A 3 3 CONTROLS INDICATORS AND CONNECTORS 3 4 Eachoperating control indicator and connector located onthe Model 419A is identified in Figure 3 1 The description of each component is keyed to the il lustration of that component which is included within the figure 3 5 OPERATING INSTRUCTIONS 3 6 The Model 419A may be operated on its internal battery power supply or from anac line The instru ment operates on its internal batteries whenever the ac power cable is remov
90. xd prec ww 100 Q 0 1 1 2 W fxd met flm 140 0 25 1 4 W fxd prec met flm 40 0 25 1 4 W fxd prec met fim 14 0 25 1 4 W fxd prec met fim 4000 Q 0 25 1 4 W fxd prec met flm 1400 Q 0 25 1 4 W fxd prec ww 400 Q 0 1 1 4 W fxd 3 0 5 1 2 W fxd prec e fim 100 Q 0 5 1 2 W fxd prec flm 900 Q 0 5 1 2 W fxd prec fim 9000 9 0 5 1 2 W fxd prec flm 90 0 5605 1 2 W fxd prec c flm 906 0 5 1 2 W fxd prec c flm 9 06 0 595 1 W fxd comp 1000 2 5 1 2 W fxd comp 15 10 1 2 W R R R R R R R R R R R R R R R R R R R R R R R Switch pushbutton function Switch slide DPDT non shorting 0 5 amp 125 Vdc 3 amp 125 Vac Cable Assembly power MISCELLANEOUS Connector 22 ribbon type contacts Cover bottom 7 x 8 Cover side 6x 8 Cover top 7x 8 Foot Assembly half module Foot Assembly half module front Holder battery BT1 thru BT4 Holder battery phenolic base BT5 Holder fuse extractor post type Insert RANGE Knob pushbutton rectangular gray plastic Knob round 5 8 diam black ZERO and NULL Knob skirted bar 3 4 diam black RANGE Label pushbutton BAT TEST Label pushbutton FAST CHG HP 419A DC Null Voltmeter max 00419 61901 CB6845 CB2241 CB6831 CB2231 CB1255 CB3941 CB1245 CB3935 CB1231 EB5321 EB 1031 E 20 MF 6C MF6C MF 6C MF6C MF6C 20 305
91. y Neon Driver Not Assigned C fxd my die 1 0 pF 10 50 fxd my die 0 47 uF 10 100 vdew C fxd poly die 0 1 uF 20 200 vdew Not Assigned Diode Si 50 mA at 1 Vdc 20 piV Not ssigned fxd prec ww 100 0 1 1 2 W Photocells part of A3 not separately replaceable Assembly amplifier C fxd Al elect 10 pF 75 10 15 C fxd elect 200 uF 100 10 3 C fxd die 0 001 uF 100 20 500 vdcw fxd die 4 7 uF 10 35 vdew fxd cer die 0 001 uF 100 20 200 vdcw HP 419A DC Null Voltmeter max 96289 91418 96289 06289 93332 07910 93332 04713 86684 24446 04713 01121 01121 01121 01121 11450 01121 01121 71450 01121 01121 01121 28480 28480 28480 28480 56289 56289 84411 01281 01686 28480 28480 56289 56289 12982 56289 12982 Model 419A Type 30D TA 30D106G025 BB4 192P10392 03072 CD35658 D3072 5211827 233053 253391 SM4713 EB1511 EB7515 5611 EB3331 XQS 200 4781 5105 XQS 200 EB4721 EB1051 EB4141 9100 0172 9100 1319 00419 63001 1990 0214 148P 148 4791 863 UW PS55353 20 00419 63001 00419 66504 30D106G015 BA4 30D207G003 DC4 801 010X5G 01027 150D475X903 oB2 4801 010 5 01022 01779 2 Model 419A Section VII Table 7 1 Replaceable Parts Cond REFERENCE hp DESIGNATOR PART NO DESCRIPTION MFR PART NO

HP 419A User's Manual

Contents

Download Pdf Manuals

Related Search

Related Contents