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6627A/27A,6628A/29A Service manual

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1. 5V 5V e 1 A 2 20 1205 2 W608 Bob Bab Bob Bob Bn log e SELECTOR DLL ALLE S lt F ALLE SS S L See R239 1252 2493 1 P205 bes gt NTSB PES NCES ACES NCES NCES NC KE SNES RY LxA LxA Re Y LxA Rx N Xx N XS 8 9 0212 ANN CAL LOCKOUT oR gtr gre garg lt 80 lt 8 SZ 204 rgo Sida igr rg
2. 2N5551 Figure 6 3 Output 1 2 Board Schematic Diagram sheet 3 of 5 C451 U READBACK 0554 5 I SOURCE REF 0350 0 1 4 s m 500 HIGH RATL R624 15 4 gt WNN 2N4393 VISAUD 150 Bal lt SENSE 16 20 3 4 5 7 4D 3 Nals 7 6 U279 U279 7 R471 A 6 2 E E U REF 2 i 5 2 zok tosk A ON OFF 7 5K 3 16M C411 C413 FEEDBACK 4 2 m C435 s CEN E 5 4 2500 22 R415 CL C3 R491 28509 10K 0351 5 EC 4 7 R412 ex 8 Sa R488 ug 340K 1 44 1 44 61 9K 6 OUT TERM 2N4393 D 4 gt 80K 6 C436 C414 8 15U 15U CV DAC BUFFER ME T 1 1000 OUT GUARD ZU 9380 5 CR351 OUT TERM z 4 15U 4 5 4 SENSE CU CL CONTROL 0581 18 7K R438 0552 5 5 5 GUARD 6 6 SA Bd 4K R507 SA Bd 4 5 gt 5 2A Bd 1K 0459 R439 15U PPSA 1744 15U R512 15U K 150 R413 CU CL CONTROL 10M 150 4 2 1444 ON OFF R445 3 4 5 7 1K 5 0579 4 3295 CR348 pase R 6 ANN ANN UOLTAGE LOOP 5 gt R483 8 10K 95K QU 2 BD 509 29379 0 1N645 2325 NOT SE 20K PF 015 USED 1200 1563 1000 Y 4353 S Vv 7 0V 2 0 1 USED 4 150 500 2N4393 D R481 71502 4 198 00 TERM DRTUE R420
3. Sore O 0000 0000 o ire ESES irao 79 O end m 48 59 MELISS eoon kk oon soon erene 3 bd 6060056 SPRO KOTO 550 240224 1 299 9 eese thor uin e 9 95 MI q 2229 sole SIE STen szen di ofall a Ole soo leleled MN n 8 22 0555 0000000 0006 oooo 221210 h teen 9 Q O oooooo 5 2 Nom o oocom A 2 010 9 9 9 MISS beeen 9 oooooooB 00000000 ooooooon EI 10 1 seen 9ogn von 10 09 R WE o 9 99 44 0050000 Sczn 895 geen eo9gn m m m ML O O TM Doooooo 00000000 00000000 00000000 69 No LO 181 6 E N rx JO Dx s Joll 4 n njej iz o o ajad ojlo jojolo Gm 2 2 9 DOOO0000000000 o o att grzac yi 000 0000000000 LIT 9 oc Sms mas o Teen i T 9
4. 3 4 3 19 Constant Current CC 3 10 3 27 EXTENDTED 5 3 13 3 28 Output Drift Tests 3 13 Section IV TROUBLESHOOTING 4 1 INTRODUCTION se ea aaa EN 4 1 4 2 ELECTROSTATIC 4 1 4 3 REMOVAL AND REPLACEMENT 4 2 4 4 Top Cover Removal 4 2 4 5 Gaining Access to Assemblies in the Supply 4 2 4 6 GPIB Board 4 2 4 8 DUSTCOVERS te Ai 4 4 4 9 Replacing the Power Module U338 4 4 4 10 Front Panel Removal sse 4 4 4 11 Chassis Mounted Components 4 5 4 12 TEST EQUIPMENT 4 5 4 13 FUSE 4 5 4 14 INITIAL TROUBLESHOOTING AND BOARD ISOLATION PROCEDURES 4 8 4 15 Power On Self Test a a q 4 8 4 16 Connector P201 Jumper 4 9 4 17 ERROR Codes and 4 9 4 18 GPIB BOARD AND FRONT PANEL TROUBLESHOOTING PROCEDURES 4 13 4 19 Test Setup s
5. 2049 90 989 seen even 0553 Proj mar 6 17 Oo S 2264 9Tr3 olf x 5 9 9 cere o o 2149 N LLL a a 1 4
6. o m 999999 R 2000 Mr D pecen m ozen are no 6Ten sosen 2 pocoo 7555000 0 000000000 A 00000000 0000000 hy z dz 0000000 S Qj io la 14 aojojojo a 1000000 D le 00000000 1 0000000 9 12552214 2 9 24 9 9 it iN 93 eff o 4 Is HN oll oy oy SL ip i EN zren 2 2 5 lo 5 N Lo 0000000 ER O f ocen 69en bi 9 1 10606606 H000000000 2 e gzz5re jo i Gze9 Eh nap ooen a STEN FE 1 PSP 5000000060 od te bu 9 3 9 999 oooooooooork Fa s SIS e 9329 noom 55 a 2 erre TER 0100000000 pn o D ropie ol Jor o 554 5 dh O O 5 9 GO Jer sco 1 19779748 T u 0 lt owl M vmv geen M llolelololelel M 222020 1990000 Ojo olo o po LO O 5527 22 lt 2 056005 nN 0000 7 O S O OTEN N a eee MD oren a O 0000000 9 0 5 2244 9927919959 9919999979
7. u 5 M G R386 Lo u S sss 918338 9 302 e 4 2999972 TTT EJ 9 oo m ae 3s mln ki OY e xj een mE m PENN esen 9 aren Ada 21512 Jte 5 0000 nooo 184422 mooo nooo 24 0000605 0550 9 1 5 TT oor 17 ooooooo oooo Z 1 o 999 salk teen RE p osen e Mjo PLE 02 000000 nooo LPR 4 94 m oTBENo 0 22 90 o ro edr voLe noo oo o o oD U Njo 00000000 00000000 00000000 Nia vaen S IZN 9gogzn S9zn o ala Hooo a 00000000 00000000 00000000 22 1 oooooooo oooooooo cogn geen gogn yyy 10000090 00000000 olo 00000000000000 O lt 01779 als a Ki s o o O to IMI M gt 5 04 O 24 1 DM sora 5 99009 0000000 Teen szen 0
8. o C3150 e P 9320 6 7 Figure 6 3 Output 1 amp 2 Board Component Location ISOLATED 3MM P302 4 lt pis P302 1 lt SES 5 302 56 P302 2 ISOLATED 3MM GND HIGH FOR DATA XFER V AS A4B D 2 A3B R327 NNV 1 1K C323 120PF 1000 50 L ISOLATED 3mm 0358 7 1 560 w a o POLR 0512 1 68705 3 5 68 RESET SR INT w SU lt 5 UCC EXTAL ns Y200 PAG A4 C325 C324 E 2 PA4 STATUS RESET 0 1 PAZ POV DISABLE 22PF 500 1000 4 6 PAZ OUT ENABLE 2 PAL R328 0 R338 8 LB sk 9 2 1 5 R328 FOR PB3 MC68705 Ra 5U 15 CS0 b CSi R611 CS2 50 5 21 5 CS4 R610 NA V gt 5U 21 5K NOTES UNLESS OTHERWISE SPECIFIED UAW Nb ALL RESISTOR VALUE ARE OHMS 1 1 8W ALL CAPACITOR VALUES ARE IN MICOFARADS DENOTES THE TERM NOT HU DENOTES HIGH VOLTAGE NU DENOTES NOT USED 18 CSi Tz 12 359 DBCZ 2 08 6 8 DBCS 9 DB A 10 DBC3 11 DBC2 12 DBC1 13 08000 14 20 DB 0 7 C329 0 1 509 055 2 A4B 15 A3B DBCZ 2 DBC6 8 DBCS 9 DBC 4 10 08032 11 DBC2
9. EI z m w NN Bggos ce a 18 IF EN mm 0212 C234 R248 EM wos BLE U214 elie R mm ay 209 R250 MIE pt lt gt R25 mm lt BM gt 27 EZE R252 mm 7221 us 55 iimmm Z gt ER 3 202 0901 R225 R254 U281 R224 EX This surface mount GPIB assembly applies to models starting with the following serial numbers and up 6625A 3738A01389 up 6626A 3737A02259 up 6628A 3738A00727 up 6629 3738A00968 up Electrically and functionally this assembly differs somewhat from the previous GPIB assembly The surface mount GPIB assembly is not repairable to the component level so a parts lists is not provided Signature analysis repair is not available for the surface mount GPIB assembly This board has a 4 position switch on it located next to U206 that replaces the function of connector P201 described on page 4 8 of this manual The switch selects the following functions Switch 1 the model function ON selects models 6621A 6622A 6623A 6624A and 6627A OFF selects models 6625A 6626A 6628A and 6629A As shipped position OFF Switch 2 selects calibration lockout
10. 2 8 Output Board Post Repair and Calibrati 4 28 Output Boards Interface 2 2122 2 4 P Performance Test Record 3 15 Power Mesh and control Circuits 2 10 Principles of Operation AC Input 2 1 GPIB a 2 1 Front Panel 2 1 Output Boards Interface 2 4 GPIB Interface 4 saksa 2 3 Output Boards Interface 2 4 Microprocessor and Clock Circuits 2 4 Data Latches and Buffers 2 4 Free Run Signature Analysis Jumpers 2 4 Address Bus and Address Decoder 2 4 Memory ROM and 2 4 Real Time Clock tone EA 2 4 5 Safety Considerations 0 02 1 1 Secondary Interface Circuits 222 2 8 Self Exercise Routine on Output Board 4 28 Setting the Model 4 11 Signature 4 12 System Micro Computer 2 22 2 4 Temperature Coefficient Tests 3 11 lest Equipment wa 3 1 Test Measurement Techniques 3 4 T
11. Table 5 7 25W 0 5A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No R396 0757 0200 RESISTOR 5 62K 1 125W TF 24546 CT4 1 8 TO 5621 F R397 0757 0481 RESISTOR 475K 1 125W TF 19701 5033R 1 8 TO 4753 F R398 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R399 0757 0464 RESISTOR 90 9K 1 125W TF 24546 CT4 1 8 TO 9092 F R400 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R401 0698 4099 RESISTOR 139 1 125W TF 07716 R402 8159 0005 RESISTOR ZERO OHMS 72982 R403 NOT USED R404 0757 0429 RESISTOR 1 82K 1 125W TF 24546 CT4 1 8 TO 1821 F R405 0698 5089 RESISTOR 33K 1 125W TF 24546 CT4 1 8 TO 3302 F R406 0683 4715 RESISTOR 470 5 25W CF 01121 CB4715 R407 NOT USED R408 0811 3822 RESISTOR FXD R409 10 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R411 0812 0010 RESISTOR 3K 5 3W PW 07088 R412 0698 4536 RESISTOR 340K 1 125W TF 07716 R413 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R414 0757 0469 RESISTOR 150K 1 125W TF 24546 CT4 1 8 TO 1503 F R415 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R416 18 NOT USED R419 0698 4435 RESISTOR 2 4K 1 125W TF 24546 CT4 1 8 TO 2491 F R420 0683 3305 RESISTOR 33 5 25W 19701 CR 25 1 4 5P 33E R421 0698 3449 RESISTOR 28 7K 1 125W TF 24546 CT4 1 8 TO 2872 F R422 0698 8827 RESISTOR 1M 1 125W TF 03888 R423 0757 0401 RESISTOR 100 1 125W TF 24
12. as 13 D 0 7 A 0 15 U281 5 DFI 5 POST PM m ve NZ E o 74 573 287 W HEADER 700 Lb 3 Ra 31 nei VSS 2 0699 8958 o OR z NY 1821 1256 19 op po og R250 oPr 7 Ed 18 AV e 750 7 e VDD EVSS Di 287K A OPTO PON m 8 Mu ud 22 1 2 17 op po 4 p2 0699 3958 R251 9 9 S pH i 4 16 os pa l5 A gt voc MIE C236 15 04 p4L 5 5 R252 0699 3958 36v e U208 AS 14 os 57 56 VV C ee NB 1820 5941 1UF 10 13 8 ps a R253 M 74 8 _ NC 16V 7 As Q6 D6 0699 3958 R25 0219 95 2198 o S S a wc 55 8 A 0 15 sv 0160 7736 m 12 9 VAA 9 3 a4 NC amp 1 8 081 9 81 851 A13 2 114 act u 7 D7 287K A a STES DIES 875286 se 3 113 cz EY 14 0215 11 o R254 0699 3958 5 ACTO4 o 8 O 88 82 s 14 02 ja EEE E z ei g H2 552 ZAACTSD o 2 87K 5 g a 4 1410215 5 18 182059447 1820 8482 0699 3958 6 10 55 7AACT32N 6 gore GND RY 05 1820 5944 2 7 222 aS 4 10 REF PIN SEQUENSE ESI 96 9 m 55 ao uu AS 5 7 8 8 202 210 1 NS me 1 RE oda X pos jt P203 1252 076 5 8 GND J 53 oda 2 PIN 58 POST A 0 15 8 1 209 10 Oa 9 3 Q223 PON oo F204 t sy M E lt og s 127 88 1252 0761 7 CR205 E ol G 8
13. CHECK 352 U3 3 1974 0358 AND 0351 CHECK 0347 0977 Figure 4 13 Output Held High Troubleshooting 4 42 RN OUTPUT S OVERVOLTRGE CIRCUIT WILL NOT TRIP OUTPUT VOLTRGE CAN BE PROGRAMMED TURN ON SUPPLY IF THE BIAS REFERENCE AND RAIL VOLTAGES HAVE NOT BEEN CHECKED DO SO NOW AS DESCRIBED IN FiG 4 8 SHEET 1 PROGRAM THE VOLTAGE TO FULL SCALE AND THE OVERVOLTAGE TO 1 5 FULL SCALE CHECK OVDRC RMPLIFIER U363 818 SEE FIG 4 10 0338 SCR MAY BE FIRED BUT A STATUS PROBLEM WITH 032 MAY EXIST SEE FIG 4 17 CHECK R356 R361 R345 C352 CR311 AND CR312 CHECK 0327 SEE FIG 4 15 CHECK RS 1 9352 CHECK FOR 0338 11 SHORTED TO COMMON Figure 4 14 OV Will Not Trip Troubleshooting Flow Chart 4 43 Table 4 15 Microcomputer 0312 Pin Measurements During the Self Exercise Routine Low common Pulses High VCC 4 MHz sine wave 2 V P P 4 MHZ sine wave 2 V P P High VCC Low Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses Pulses 1 sec Low High Pulses Pulses Pulses Pulses Low to High Turn on Referenced to Common NN ON QI EO N m 4 29 Troubleshooting Analog Multiplexer 0323 and Readback Using VMUX Command Analog multiplexer U323 and readback switches U365 U366 directs one of several inputs to the readback signal comparator U324 see paragraph 2 31
14. CC UNR 15 V pin 8 The 15 V bias voltage can range from 14 V to 15 66 V UNREG pin 9 The UNREG unregulated output signal open collector takes on the state of the internal UNR flip STATUS SELECT pin 11 is Low The CLO pin 10 The CLO current limit output output signal open collector takes on the state of the internal CC flip flop when STATUS SELECT 11 is Low The CC mode is indicate when CLO is Low Figure 4 17 shows the condition that cause CLO to be Low CLO is open STATUS SELECT pin 11 This input signal when Low causes the four status conditions held in the flip flops as well as the overvoltage and overtemperature signals to be transferred to the six output pins on the data bus CVO is High the six output pins are open circuited OV pin 12 This open collector output pin goes High when STATUS SELECT pin 11 is Low and the OV SENSE pin 13 is Low The Low state of pin 13 indicates an overvoltage condition OV is open circuited when STATUS OV SENSE pin 13 When an overvoltage occurs pin 9 on the power module goes Low this input pin goes Low SELECT pin 11 is Low 4 48 THERM pin 14 This input signal when Low indicating an overtemperature condition causes OT pin 15 to go 14 inputs are Low indicating an OT overtemj2erature condition OT is open circuited when STATUS SELECT is High CL LOOP pin 16 This input signal when Low
15. P 0000000 x 9 09 0 BETS o 0000000 0000000000 48717 580595 Hae 5850 101222 o 00000000 PPP ozen Lo 0364 47 43350 O amp bRz9be e R393 e R391 R33 R392 Cp R411 0518 9 re C370 e Rz96 o m DRz2b9 e Rzsg e 52 94 H e c37are 6452 Q 0319 n of Jo oo jo ol 2 Jo 9 125921 9 90289 430 5429 434 590 250 9 e R414 o 0000 eee nooo e czogl e B R351 0 9 6536 6 C458 0 Dooooooo R372 e a ao in io tr odor 22142 9999 iai ki 24822 Be P
16. Table 5 7 25W 0 5A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg No Code Part Na R451 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R452 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R453 0698 4480 RESISTOR 15 8K 1 125W TF 24546 CT4 1 8 TO 1582 F R454 0698 6360 RESISTOR 10K 1 125W TF 07716 R455 0698 8827 RESISTOR 1M 1 125W TF 19701 R456 0698 0087 RESISTOR 316 1 25W TF 24546 5 1 4 3160 R457 0811 2553 RESISTOR 7 5 5 2W PW 75042 BWH2 7R5 J R458 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R459 0757 0446 RESISTOR 15K 1 125W TF 24546 CT4 1 8 TO 1502 F R460 0698 8913 RESISTOR 1 5 1 125W TF 07716 R461 0683 4735 RESISTOR 47K 5 25W CF 01121 CB4735 R462 0757 0288 RESISTOR 9 09K 1 125W TF 19701 5033R 1 8 TO 9091 F R463 0698 0084 RESISTOR 2 15K 1 125W TF 24546 CT4 1 8 TO 2151 F R464 0757 0124 RESISTOR 39 2K 1 125W TF 07716 R465 0698 4484 RESISTOR 19 1K 1 125W TF 24546 CT4 1 8 TO 1912 F R466 70 NOT USED R471 0699 0070 RESISTOR 3 16M 1 125W TF 07716 R472 0698 6363 RESISTOR 40K 1 125W TF 07716 R473 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 6811 F 474 6 NOT USED R477 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R478 80 NOT USED R481 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R482 NOT USED R483 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1
17. Design Agilent Part Description Mfg Mfg No Code Part No R391 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R392 0757 0282 RESISTOR 221 1 125W TF 24546 CT4 1 8 TO 221R F R393 0698 0435 RESISTOR 2 49K 1 125W TF 24546 CT4 1 8 TO 2491F R394 0757 0473 RESISTOR 221K 1 125W TF 24546 CT4 1 8 TO 2213 F R395 0757 0431 RESISTOR 2 43K 1 125W TF 24546 CT4 1 8 TO 2431 F R396 0757 0200 RESISTOR 5 62K 1 125W TF 24546 CT4 1 8 TO 5621 F R397 0757 0481 RESISTOR 475K 1 125W TF 19701 5033R 1 8 TO 4753 F R398 0757 0280 RESISTOR 1K 196 125W TF 24546 CT4 1 8 TO 1001 F R399 0757 0464 RESISTOR 90 9K 1 125W TF 24546 CT4 1 8 TO 9092 F R400 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R401 0698 4099 RESISTOR 139 1 125W TF 03888 PME55 1 8 TO 139R F R402 8159 0005 RESISTOR ZERO OHMS 72982 R403 NOT USED R404 0757 0429 RESISTOR 1 82K 1 125W TF 24546 CT4 1 8 TO 1821 F R405 0698 5089 RESISTOR 33K 1 125W TF 24546 CT4 1 8 TO 3302 F R406 0683 4715 RESISTOR 470 5 25W CF 19701 CR 25 1 4 5P 470E R407 0811 3752 RESISTOR 18 5 2W R408 NOT USED R409 10 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R411 0812 0010 RESISTOR 3K 5 3W PW 91637 R412 0698 4536 RESISTOR 340K 1 125W TF 07716 R413 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R414 0757 0469 RESISTOR 150K 1 125W TF 24546 CT4 1 8 TO 1503 F R415 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R416 18 NOT USED R419 0698 4435 RESISTOR 2
18. h Reset the output by setting the OV to 55V and resetting the OV circuit as shown below OVSET lt ch gt lt 55 gt OVRST lt ch gt i Check that the front panel again displays the programmed output voltage and no current j Repeat steps b through I for each output in your supply 3 19 Constant Current CC Tests 3 20 CC Setup Follow the general setup instructions of paragraphs 3 5 through 3 9 and the specific instructions given in the following paragraphs 3 21 Current Programming and Readback Accuracy This test verifies that the current programming GPIB readback and front panel display functions are within specifications An GPIB controller must be used for the READBACK accuracy part of this test The accuracy of the current monitoring resistor must be 0 005 or better a Turn off the supply and connect a 0 1 ohm current monitoring resistor across the output and a DVM across the resistor see paragraph 3 8 b Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel c Select the low current range and program the output voltage to 5 V and the current to zero by sending the following strings IRSET lt ch gt lt 015 25W or 2 50W gt VSET lt ch gt 5 ISET lt ch gt 0 Divide the voltage drop across the current monitoring resistor by the value 0 1 to convert to amps and record this value Io Note also the current reading on the front panel display The readings s
19. n Protective earth ground terminal Out position of a bi stable push control ume Frame or chassis terminal On supply N Terminal for Neutral conductor on Off supply permanently installed equipment Terminal is at earth potential l Standby supply I Used for measurement and control Units with this symbol are not completely circuits designed to be operated with disconnected from ac mains when this switch is one terminal at earth potential off To completely disconnect the unit from ac mains either disconnect the power cord or have a qualified electrician install an external switch Herstellerbescheinigung Diese Information steht im Zusammenhang mit den Anforderungen der Maschinenl minformationsverordnung vom 18 Januar 1991 Schalldruckpegel Lp 70 dB A Am Arbeitsplatz Normaler Betrieb Nach EN 27779 Typpr fung Manufacturer s Declaration This statement is provided to comply with the requirements of the German Sound Emission Directive from 18 January 1991 Sound Pressure Lp 70 dB A At Operator Position Normal Operation According to EN 27779 Type Test Edition2 September 2001 Copyright 2001 Agilent Technologies Inc CONTENTS Section INTRODUCTION 14 SCOPES x aetate 0 da 1 1 1 2 SAFETY CONSIDERATIONS ccce 1 1 1 3 INSTRUMENT AND MANUAL 1 1 1 4 FI
20. 12 GCLK 10 5CLR S8 Bd 3 336K 2A Bd 15 9K 15 MSB U I MUX DCO D 0 7 Al is SS SSSI Qa 5 sc6 CS6 az sc 1 gt 04 4 sca a5 5 sc9 Q6 5 SC10 Q2 5 SC11 sas 5012 HC595 GO LSB 8 NZ RSE ah I MONITOR on a 1 2 SWITCHES 3 4 GAIN SELECT DUT GUARD n GUARD SENSE SWITCHES a 5 BUFFER READBACK R605 ANY 21 5K Figure 6 4 Output 3 8 4 Board Schematic Diagram sheet 5 of 5 6 18 AC Input Circuits us n 2 1 Bou 3 7 COVEN OSES da dote decus 3 4 Component Locations and Illustrations 6 1 Connector P201 Jumper esse 4 8 Electro Static Protection 222 4 1 Error Codes and Message 4 8 Extended Tests 3 10 Firmware Revision a 4 12 Firmware ReVisions a 1 2 Front Panel Removal esse 4 4 Fuse Replacement 70 ene 4 5 Gaining Access to Assemblies in the Supply 4 2 H GPIB Boat ehe 2 3 GPIB Post Repair and Calibration 4 11 How to Order Parts 3 10 Instrument and Manual Identification 1 1 Operation Verification Tests 3 1 QUtPUE Board iis ac
21. 0 0 0 7 CS0 55 CS6 m 8 Figure 6 4 Output 3 amp 4 Board Schematic Diagram sheet 1 of 5 6 14 F308 UNREG BIAS P301 1 lt A R308 HS6 gt 5U 0200 0202 BIAS LM317T LM317T 15U 301 2 4 F309 P301 3 lt 2A C315 R303 5 EXTRA PAD Q HP34 5200PF 1 3K 4 7 FOR C308 250V A 0501 9503 0 7 0U LM337T LM337T 150 OU DAC 0 TO 10U CR310 1 CO SHUNT DROP COMP R345 5191193 ANN 1 8 Dco 3 16M 15U UNREG ir ENABLE RZ58 2R357 1 2 4 gt POV DISABLE 402K R365 5566 14 aps MED RAIL R359 R361 TERM 19K 1 c 14 5 LI OSK 1x 0 C352 SEB UNREG BIAS ZNCR311 2 54 N CR312 R356 01 1 5 500 U REF 1 D 0 2 NY TURN ON CKT COMP 6 ep L REMOTE DV TRIP JD 6 VOLT_LOOP C EE OT cL LODP l8 4 LOOP agen DCS UNREG 0L LODP zl GU SENSE 6 81K 3 DUT_ENB OU_SENSE lt 1 27 POU DIS CAP_IN BIAS TRIP 3 4 STATUS RESET SS ON OFF 1 Z STAT_RE THERM 14 1 4 THERM vDD 5 5U STAT_SEL UCC 28 15U PCLR U
22. 10 Blown Fuse 3 Vin 3 0 10 4 USED 5 Vfs 50V range to 10 6 CV DAC 0 to 10 7 CC DAC 01 10 8 OV DAC o to 10 9 CLR 0 to 10 10 to 10 to 10 01 10 01 10 low range I high range 1 low range high range low range I high zero I low zero V zero V high range TAWWWWWWWWW 00 NO gt O OO m m OO m m QQ O OOOO m O u mm OO m m m m a m m m m O O gt O m m m m m gt a m O O O m m m a m m O O O gt O m m m MO 4 45 P 0 u32 OVERVOLTRGE CIRCUIT POV DISABLE OV COMP POV DISABLE OV TRIP OV DRIVE Figure 4 15 Signal Processor U327 Overvoltage Circuit Simplified Schematic Diagram Figure 4 16 Signal Processor U327 Power On Start Up Circuit Simplified Schematic Diagram 4 46 NOTES Table 4 17 Signal Processor U327 Signal Levels SIGNAL POV DISABLE OV TRIP Bias Return Output Input Bias Common OV DRIVE STATUS RESET 15 V UNREG CLO STATUS SELECT OV Status Output Status Output Input Status Output OV SENSE THERM OT CL LOOP Status Input Status Input Status Output Status Input 7 00 V CLO Bias Status Output CVO CL LOOP Status Output Status Input CV LOOP Status Input Bias Return Time Delay Input Common DELAY CAP OUTPUT ENABLE ON O
23. 2 38 Rectifier and Filter These circuits consist of two full wave bridge rectifier circuits with filter capacitors connected across the rectifier outputs The proper ac voltage levels are applied to the rectifiers via secondary windings of chassis power transformer T1 see Figure 2 1 The rectifiers provide raw dc o the power module at three different levels high medium and low power rails The return line for the rectifier circuits is fuse protected If this fuse opens the power supply will fail self test all outputs will be disabled and the error message FUSE CH lt n gt will be displayed where n specifies the particular output board 1 4 2 39 Power On Circuit and Current Sources The power on circuit Q318 and Q319 is used to turn on the current source transistors and the bleed circuit see paragraph 2 43 which is connected across the output of the supply The power on circuit is activated when it receives the ON OFF signal 2 4 V level from the signal processor U327 The current sources U336 are a series of transistors connected to the high rail When activated by the power on circuit the current sources supply a few milliamps to the BASE DRIVE in conjunction with the DRIVE signal see BASE DRIVE CIRCUIT description below control the conduction of the series pass elements and shunt CL in the power module 2 40 Power Module Reference Voltage When the current sources have been turned on this circuit
24. 2350 56 VOLTAGE 0358 0351 86 7 CHECK 0322 Figure 4 12 Sheet 2 Output Held Low Troubleshooting Flow Chart 4 40 CHECK VOLTAGE FROM C366 OUTPUT TERMINAL VOLTAGE CHECK FOR OPEN CR325 CHECK 4V7 POWER MODULE U338 NO YES MERSURE THE CURRENT GH CR325 BY PUTTING FN RMMETER CR325 WHICH SHORTS THE CHECK POWER MODULE 338 CHECK U337 U340R gt YES NO CHECK U34QD CHECK U336 j CHECK FOR OPEN U33 OR 3408 CHECK FOR OPEN VR3SQ 8319 COLLECTOR YES CHECK 0318 CHECK FOR LEAKY 7V C378 NO Q341 SOURCE gt 3V CHECK Q341 NO Figure 4 12 Sheet 3 Output Held Low Troubleshooting Flow Chart 4 41 WARNING WITH R498 OR RSO LIFTED AND THE SUPPLY TURNED ON HIGH OUTPUT VOLTRGE MAY BE PRESENT EVEN IF THE OUTPUT IS NOT PROGRAMMED LP 5 PERMANENTLY AS PER FIG 4 11 TURN ON SUPPLY AND PROGRAM TO ZERO OR TO VALLE THAT ORIGINALLY CAUSED PROBLEM CHECK THAT CVDRC OUTPUT 6 IS APPROXIMATELY SCALED TO THE PROGRAMMED VALUE WHERE TO 18 ON THE DRC ROUGHLY CORRESPONDS TO 8 TO FULL SAE PROGRAMMED VALLE CHECK CVDRC RMPLIFIER 0313 1358 SEE FIG 4 18 CHECK 0364 1378 EACH RESISTOR R379 R388 AND R381 IS 1 2 REFER THE FIG 4 12 SHEET 2 RND COMPARE TO VALUES BELOW RSSUMING NO LORD ON OUTPUT MIN 8428 MAX R428 VOLTAGE VOLTAGE 8 32V a sev CHECK 0321 AND 338
25. GUARD 19 ox Vv 02 EOI EOI 5 7 5 vos 19 bs n N Z PD3 198 02 4 7 2258 0259 A 8 AS 5 V e PA3 l20 BR D2 Q2 8 8 16 PIN ATNI AG 6 20 PD4 82 35 p 5 6 91 sri sRa1 2 16 17 oi ag 5 21 ETZB gt 98 EE DISPLAY 8 SRQ AT vos p n udo PAS 57188 6 04 HEADER 5 os AB GI M 4 7 zas cow 1 5 1296514 198 a A 24 po 13 pop 2 ma 02 PAG RESET 2 10 A aud pi 14 ES 5v Sel PA7 D6 GND ATES AAA 114 pot 9 MODA L R256 sy w 9 2 10 85 10 082 C IK 02 15 ato 24 An e lao AA D7 a7 95 mz 29 Da2 og 8 mops 07 1820 8461 2 B 11 WE 0699 1318 18 8 C 2 N V ay 2 4 1 11 Ce GR A9 A9 0699 1318 GND N 7 NZ A12 NC1 p 19 3 At2 acra 14 Do V DQ4 A12 gt z8 37 A10 10 28 lt 38 0219 a Di A13 ps 20 30 arg 58 Di 3 005 A13 13 Am 36 A11 5 D2 a ps 21 Dae A14 m 35 aap Dz m 2 07 221007 A15 Le A13 03 7 m PCR E A16 X5 1818 5681 SELECTOR D4 pe R247 ES 1818 5292 as 3 GND Ro SIM 05 B as m NAN REL_1 1 P209 14 0215 lt 28 32 A15 lo D 0 7 287K A is 914 GND og 16 2 1252 1152 We NG 5 6 R248 0699 3958 gy lt CONN 74ACT32N_8 16 D7 10 D7 20 AAA Ws 3 Q 1820 5944 5 K 5059 4 FO 287K 4 E 0699 3958 m 10PIN C 1140215
26. raid N 9000000 iuo ko SNNINN e TSEN vimjo s x t ohn olji iyo Hoooooo u oz O fo ae ye 24 4441 6606808888 oo ooo O Le o Ho 18 O I x im Lo OJ o gt nz c Lo 9 242214 ir 9059 MM EEA B 5159 y o Q D F308 C3150 6 13 Figure 6 4 Output 3 amp 4 Board Component Location ISOLATED 3MM DTS P302 P302 P302 P302 ISOLATED CKT 3MM HIGH FOR DATA XFER V A4B A3B ISOLATED 3mm C32e 0 1 500 w 2 D PCLR 03512 1 MC68705PZ 5 68 RESET sA INT W 5U4 3 ucc EXTAL PAZ a5 Yz00 PAG A4 0385 C324 PAS 2 PA4 STATUS RESET 0 1 POV DISABLE 22PF 500 1000 4MHZ 6 OUT ENABLE 5 PAL PAO 8 R338 4 PB 5 11K 5 10 R328 FOR 11 MC68705 5U 15 CS0 b Yipid CS1x R611 vaol3 csz 50 Y3ol csz 21 5K Yapti 054 R610 YSP VWY gt 5U vY6o3 21 5K 2 x NOTES UNLESS OTHERWISE SPECIFIED 1 ALL RESISTOR VALUE ARE IN OHMS 1 1 8W 2 ALL CAPACITOR VALUES ARE MICOFARADS 8 DENOTES TERM NOT 4 DENOTES HIGH VOLTAGE 2 DBC 0 7 USS w OGND 6
27. 125W TF 91637 R366 0699 1722 RESISTOR 9 75K 1 125W TF 91637 R367 NOT USED R368 8159 0005 RESISTOR ZERO OHMS 20940 R369 71 NOT USED R372 0683 0335 RESISTOR 3 3 5 25W CF 19701 CR 25 1 4 5P 3E3 R373 0698 4470 RESISTOR 6 98K 1 125W TF 24546 CT4 1 8 TO 6981 F R374 0757 0452 RESISTOR 27 4K 1 125W TF 24546 CT4 1 8 TO 2742 F R375 0686 2225 RESISTOR 2 2K 5 5W CC 01121 EB2225 R376 0686 4725 RESISTOR 4 7K 5 5W CC 01121 EB4725 R378 0698 4446 RESISTOR 267 1 125W TF 24546 CT4 1 8 TO 267R F R378 0757 0438 RESISTOR 5 11K 196 125W TF 24546 CT4 1 8 TO 5111 F R379 0698 5347 RESISTOR 495 5 1 125W TF 19701 R380 81 0698 3510 RESISTOR 453 196 125W TF 24546 CT4 1 8 TO 453R F R382 0757 0465 RESISTOR 100K 196 125W TF 24546 CT4 1 8 TO 1003 F R383 84 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R385 0811 1217 RESISTOR 150 5 5W PW 07088 R386 0686 8225 RESISTOR 8 2K 5 5W CC 01121 EB8225 R387 0698 4123 RESISTOR 499 1 125W TF 24546 CT4 1 8 TO 499R F R388 0683 4715 RESISTOR 470 5 25W CF 01121 CB4715 R389 0698 5088 RESISTOR 12K 1 125W TF 24546 CT4 1 8 TO 1202 F R390 NOT USED R391 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R392 0757 0282 RESISTOR 221 1 125W TF 24546 CT4 1 8 TO 221R F R393 0698 4435 RESISTOR 2 49K 1 125W TF 24546 CT4 1 8 TO 2491 F R394 0757 0473 RESISTOR 221K 1 125W TF 24546 CT4 1 8 TO 2213 F R395 0757 0431 RESISTOR 2 43K 1 125W TF 24546 CT4 1 8 TO 2431 F
28. CL LOOP 150K 15U i S GUARD R628 35 5 5A Bd 40K 100K 15U Bd ONLY 1744 R472 L R454 if 5 R633 R 1 2A Ba 500 me e 3 351 CR371 10470 R473 2A Bd lt R474 1 OUT GUARD 100K 14 R634 REMOTE OV TRIP 36 5K ONLY ONLY lt 39 2K SA Bd 10K ANV gt 2A Bd R477 R475 C4075 2A Ba 5 62K U REF 1 ANN 2 NNN 4 ONLY CR354 R451 21 5K Bek sx Tea 10007 5 R632 RAZO 2006 2 CL TOGGLE ONLY gt 03 0551 1 OUT GUARD R464 2 4 Ay 0UT TERM is 6 39 2K fe E R630 R465 21 5K 5 51509 ii U REF 1 15K R461 401 47K 5x 4i 10007 R460 R458 v CL_LOOP 5 DRIVE SINK COLLECTOR OUT 4 509 CL CONTROL 4 CL LOOP 3 Teu o 1 BLEED 541 CIRCUIT R621 R455 R506 15U UNREG 2 ANN ANN ANN 8 1 8K 5 1M 1K 3221 1 44 us u UR402 C424 mec 042UF 7 V Q343 CR363 316 50 1N645 1047UF i BLEED CONTROL 500 p BLEED SINK 4 CURRENT SOURCES R382 3 100K P403 1 hy ds P O R381 2R380 2R379 2 R377 U336 z 3 453 453 495 5 S 267 F304 0360 ae 108 022 111 1009 NOT USED P O F30
29. Output Controller Display 25W lo 19 5 A 50W Io 330 pA Select the high current range and program the voltage to 5 volts and the current to zero by sending the following strings IRSET lt ch gt lt 0 5 25W or 2 50W gt VSET lt ch gt 5 ISET lt ch gt 0 3 8 k Divide the voltage drop across the current monitoring resistor by the value 0 1 to convert to amps and record this value Io Note also the current reading on the front panel display The readings should be within the limits specified below for the particular output type being tested Prog Accuracy Display Accuracy Output DVM Reading 0 1 Front Panel LCD 25W 0 100 pA Io 130 pA 50W 0 500 A To 550 pA l Read back the output current from the selected channel over the GPIB to the controller by running the program in step e m Record the value displayed on the controller This value should be within the limits specified below using the Io reading noted in step k Readback Accuracy Output Controller Display 25W Io 130 A 50W lo 550 A n Program the selected output s voltage to 5 V and the current to the High Range Full Scale Current value by sending the strings VSET lt gt 5 ISET lt ch gt lt 0 5 25W or 2 50W gt o Divide the voltage drop across the current monitoring resistor by the value 0 1 to convert to amps Record this value lo Note also the current reading on the front panel display The readings should be
30. P O U340 and U337 provides a reference voltage about 2 V above V to the power module REF input The REF input is used by an internal control circuit that allows switching between the low medium and high rails The reference circuit includes a transistor P O U340 that turns on when the current sources apply power a programmable reference U337 which provides the reference voltage and bypass capacitors C366 and C367 2 41 Power Module The power module hybrid U338 receives three unregulated DC voltage levels on its high medium and low voltage input rails The power module contains series regulator stages an SCR overvoltage circuit a down programmer a built in overtemperature thermistor and a reverse output voltage protection diode Series Regulators The series regulator stages consist of series pass transistors which regulate the voltage received from the selected power rail The power module automatically selects the proper input rail depending upon the output voltage required For example if the low rail is supplying current and the output voltage exceeds the low rail minus about 2 5 V the medium rail begins to raise the voltage on the BYPASS input and supply current Finally if the output voltage exceeds the medium rail minus about 2 5 V the high rail will begin to supply current As stated previously the conduction of the series pass transistors is controlled by the BASE DRIVE and DRIVE inputs Normally there i
31. PA 01295 Texas Instruments Inc Semi Div Dallas TX 5 3 Table 5 5 CHASSIS Replacement Parts List Design Agilent Part No Description Mfg Mfg Code Part No Chassis Boards 06626 61026 GPIB BOARD Assembly see Table 5 6 28480 Output Board 1 06626 61020 Models 6625A 6626A 25W 5A see Table 5 7 28480 06626 61023 Models 6628A 6629A 50W 2A see Table 5 8 28480 Output Board 06626 61023 Models 6625A 6628A 6629A 50W 2A see Table 5 7 28480 06626 61020 Model 6626A 25W 5A see Table 5 8 28480 Output Board 3 Not Used Models 6625A 6628A 28480 06626 61021 Models 6626A 6629A 50W 2A see Table 5 8 Output Board 4 Not Used Models 6625A 6628A 28480 06626 61021 Models 6626A 6629A 50W 2A see Table 5 8 Chassis Cabling W1 8120 1345 LINE CORD 28480 W2 5060 3273 TRANSFORMER TO AC LINE SWITCH 28480 W3 5060 3110 FAN WIRE 28480 WA 5060 3264 XFMR ASSY PRIMARY 28480 W5 5060 3271 XFMR GPIB BIAS 28480 W6 8120 5174 GPIB OUTPUT BD 28480 W7 8120 5177 GPIB OUTPUT BD 28480 W8 6625A 6628A NOT USED 28480 6626A 6629A 8120 5175 GPIB OUTPUT BD W9 6625A 6628A 28480 NOT USED 28480 6626A 6629A 28480 8120 5176 GPIB OUTPUT BD 28480 W10 5060 3268 XFMR POWER 25W 5A W11 5060 3269 XFMR BIAS 28480 W12 06627 80006 XFMR POWER 50W 2A BIAS W13 6625A 6628A NOT USED 28480 6626A 6629A 5060 3268 XFMR POWER 50W 2A W14 6625A 6628A 28480 NOT USED 28480 6626A 6629A 5060 3269 XFMR BIAS W1
32. The instruction set for the power supply includes the VMUX command which measures the voltage at these inputs This command can be used to troubleshoot the analog multiplexer and the readback circuitry on the output board The supply may have to be put into the SKIP SELF TEST mode in order to program the output see paragraph 4 16 The syntax for the VMUX command is as follows VMUX lt ch gt lt code gt A complete description of the syntax structure is shown as C4 in Figure 5 2 sheet 1 in the Operating Manual The response to the VMUX Command is SZD DDDD see Table 5 2 in the Operating Manual of an explanation of these abbreviations The resolution of the returned voltage reading is approximately 0 5 mV 4 44 The analog multiplexer circuit is shown on the functional schematic of Figure 6 3 Sheet 1 and on he block diagram of Figure 2 4 The eight input signals to the analog multiplexer U323 are shown in table 4 16 The VMUX command reads back approximately 1 05 times the voltage that appears on the selected input Its readback range is limited to approximately 0 2 V to 10 5 V on the input pins However any positive voltage from approximately 0 1 V to 10 V on the input pins will readback about 0 2 V After the VMUX command is processed the selected switches and MUX input will remain connected to the multiplexer output U323 pin 8 as long as no other A D conversions voltage measurements take place due to
33. c Program the selected output channel to zero volts by sending the string VSET lt ch gt 0 d Record the output voltage readings on the digital voltmeter DVM and the front panel display The readings should be within the limits specified below for the particular output type tested Also note that the display indicates the output current and the CV RMT and ADDR annunciators are on Note that the output current reading is approximately zero because there is no load connected Prog Accuracy Display Accuracy Output DVM Reading Front Panel LCD 25W 15 mV DVM 2 mV 50W OV 3 mV DVM 3 5 mV e Read back the output voltage from the selected channel over the GPIB by entering and running the following program 10 OUTPUT 705 VOUT lt ch gt 20 ENTER 705 A 30 DISP A 40 END Record the value displayed on the controller This value should be within the DVM reading noted in step d and the limits specified below Readback Accuracy Output Controller Display 25W DVM 2 mV 50W DVM 3 5 mV Program the selected output s voltage to the Low Range Full Scale value 7 V for 25W or 16 V for 50W outputs by sending the following string VSET lt ch gt lt 7 or 16 gt Record the output voltage readings on the DVM and the front panel display The readings should be within the limits specified below for the particular output type tested Prog Accuracy Display Accuracy Output DVM Reading Front Panel LC
34. current The difference in the readings taken in steps I and j should be less than 70 25 or 260 LA 50W k Repeat steps a through j for each output in the supply 3 31 Long Term Current Drift This test measures the output current drift over an 8 hour period Place the supply to be tested in a temperature chamber or in temperature controlled environment such as a standards room a Turn off the supply and connect the output to be tested as shown in Figure 3 3 with the DVM connected across the 5 and 5 terminals the load switch closed and the short switch opened b Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel c Program the selected output to 50 volts and 0 515 Amps 25W or 1 03 Amps 50W d Adjust the load for slightly less than 0 5 Amps 25W or 1 Amps 50W as read on the display Check that the CV annunciator is on e Wait 30 minutes and record the output voltage reading on the DVM f Observe and record the output voltage reading periodically over an 8 hour period The difference between any two readings should not exceed 5 mV g Repeat steps a through f for each output in your supply 3 32 Long Term Current Drift This test measures the output current drift over an 8 hour period Place the supply to be tested in a temperature chamber or in temperature controlled environment such as a standards room a Turn off the supply and connect the output to be tes
35. et te dE 4 13 4 20 Post Repair 4 19 4 21 Setting the Model Number MODEL 4 13 4 22 Signature Analysis Testing 4 14 4 23 Test Setup for 5 220 4 14 4 24 Firmware Revisions ROM Command 4 14 4 25 OUTPUT BOARD TROUBLESHOOTING PROCEDURES eet een tome Tear 4 30 4 26 Test n ceo EE 4 30 4 27 Post Repair 4 30 4 28 Self Exercise Routine on the Output Board 4 30 4 29 Troubleshooting Analog Multiplexer U323 and Readback Using VMUX Command 4 49 4 30 Understanding and Troubleshooting the Signal Processor U327 eut eee 4 50 4 33 Power Module 4 54 4 34 Miscellaneous Trouble Symptoms and Remedies 4 54 Section V REPLACEABLE PARTS 5 1 INTRODUCTION LL cesse 5 1 5 2 HOW 5 2 2 CONTENTS Cont Section VI Appendix A CIRCUIT DIAGRAMS LOGIC SYMBOLOGY 6 1 INTRODUCTION 6 1 6 2 FUNCTIONAL SCHEMATIC DIAGRAMS 6 1 6 3 COMPONENT LOCATION ILLUSTRATIONS 6 1 Figure 2 1 2 2 2 2 2 4 2 5 2 7 2 8 2 9 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 3 10 3 11 3 12 4 1
36. readback either over the GPIB or internally to the front panel The A D conversions on a particular output channel can be stopped by using the front panel OUTPUT SELECT key to monitor a different output channel or alternatively simply pressing the front panel VSET ISET etc keys will stop the internal A D conversions For example if it is desired to measure the multiplexer output voltage with an external voltmeter when the CV REF signal Input No 6 on output channel 2 is selected stop the A D conversions by pressing the VSET button on the front panel Next use the following program to select input 6 on channel 2 and to display the value read back to the computer 10 OUTPUT 705 VMUX 2 6 20 ENTER 705 A 30 DISP A 40 END After the program is run a voltmeter can be used to confirm that the multiplexer output U323 pin 8 and input 6 U323 pin 11 measure the same voltage and that the VMUX result is valid The next program uses a FOR NEXT loop to read the 18 analog multiplexer inputs one at a time The readings and associated input nos are printed by the computer see Input and Response columns in the program run which follows 10 FOR X 1 TO 18 20 OUTPUT 705 VMUX 1 X 30 ENTER 705 V 31 OUTPUT 723 FIR2T1 32 ENTER 723 Vm 40 PRINT VMUX Response X V VM reads Vm 50 NEXT X 60 END A typical program run is shown below circuitry is probably defective If only on input is incorrect the ci
37. rgo rgo 528 D 0 7 1821 0300 19 e 5 5965 SKIP_SELFTEST x ERCONN CABLE 5 luge 5 59 pt A oN SA SA on SA pct 0699 1318 1 1252 2493 2 P205 GND D 0 7 10 INT O gt 320 320 320 320 320 320 3290 38 0107 74 541 Less x SA MODE 0 7 e RIBBON ses 585 585 585 585 SBS 585 ses 585 e s 3 4205 NL1251 5385 Go xe agi E 1252 2493 3 P205 5 i 14 popo S e e e e e e lis 4 4005 NL1251 5385 As 101251 8105 6 9213 0210 0204 1206 201 281 9211 0207 0230 02 16 Yo 2 4 P205 5 A6 gt 4252 2493 4 DTS A 12 6 og 5 1206 NEIST 2 Ys 5 2 D4 14 A 8 SOA g 9 j1 s 8 m 18 e 5 it 1252 2493 1 P206 DFS o N 14174 NC 2 2 A ae sH J206 NL1251 5385 2 gg 3 5 cz LxA x ExS XI x Ex 1 2 SEN Sida SEN Sida SEN SeXy SEN 121 vg 9 mo P206 n vp 5 a NC 8 8 8 oN 59 AN oN oN SN 28 oN y PE p GND pi M Ai 4 m AL LOCKOUT NC g 3 3 O 290 290 290 290 290 290 290 290 290 z9 4206 NL1251 5385 17 3 SKIP SELFTE T 1 POST 1 52 oF 525 325 595 585 585 ses 8585 2585 2585 2585 585 285 8 8 8 ab dap rand s 206 P 3 Y GE 6 19 HEADER is KEYBOARD 74 5
38. supply 3 17 Turn On Off Overshoot This test measure the amplitude of any transients in the output during turn on or turn off of the supply a Turn off the supply and connect an oscilloscope across the V and V terminals of the output to be tested b Set the oscilloscope to 50 mV div de coupled 1 sec div and slope c Turn on the supply while observing the oscilloscope The maximum transient amplitude should not exceed 100 mV Repeat test by observing the scope after turning off the supply d Repeat the test steps a through c for each output in your supply 3 18 Programmable OV Accuracy Test This test checks the overvoltage OV programming accuracy Taking the OV programming accuracy and the voltage programming accuracy into account a Turn off the supply and disconnect all loads and test equipment b Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel c Program the OV to 49 V Send the following string OVSET lt ch gt lt 49 gt d Program the output voltage to 48 44 volts by sending the following string VSET lt ch gt lt 48 44 gt e Note that the overvoltage should not trip and the front panel should display the programmed output voltage and no current f Program the output voltage to 49 55 by sending the following string VSET lt ch gt lt 49 55 gt g Note that the overvoltage has tripped as indicated by the display showing OVERVOLTAGE
39. 1 to obtain the current sink value Is in amps and record the value Record also the current reading on the display The readings should be within the limits specified below for the particular output type being tested Note that the CC annunciator must be on Neg Current Limit Display Accuracy Low Range Output V Front Panel LCD Output Is DVM Reading 0 1 25W 0 52 to 0 55 Is 3 mA 50W 2 08 to 2 20 A Is 1 4 mA Read back the sink current from the selected channel over the GPIB by entering and running the program listed in paragraph 3 21 Record the value displayed on the controller This value should be within the reading Is noted in step e and the limits specified below Output Readback Accuracy Controller Display 25W Is 3 mA SOW Is 1 4 mA For the 50 watt outputs only raise the voltage of the external supply up top approximately 30 V as indicated on your supply s front panel LCD and Note that the sink current Is changes from the previous value to between 1 04 and 1 10 amps Read back the sink current from the selected channel over the GPIB by entering and running the program listed in paragraph 3 21 Read the value displayed on the controller This value should be Is from step e 0 9 mA Repeat this test steps a through j for each output in your supply 3 23 CC Load Effect This test measures the change in output current for a change in the load from 50 Volts to short circuit Turn off the
40. 14 0 14 c3 1 3 Co PEF 1 19K 1x 9 75K U326 U326 U326 U326 U326 U326 U326 U326 U326 U326 U326 U326 OSK 1x 0 99505 1 20 0K 20 0 S20 0K S20 0K lt 20 0K Sak 20 0K Sak 20 0 20 0K lt 20 0K 0358 R360 UNREG BIAS V 2 3 4 5 6 7 8 9 10 11 12 15 01 ZNPR311 196 1 5M 50U E U REF 1 19 8 w TURN ON CKT poo 18 0 OU_COMP E CLO OV DR REMOTE OV TRIP D 10 QLO TRIPIS D 3 1 VOLT LOOP VOLTAGE LOOP D 4 15 Loop 118 CL LOOP R351 2R352 DUS z UNREG CL_LOOP Hz 34K 6 81K 4 z JOUT ENB OU SENSE 53 57 POV DIS CAP_IN BIAS TRIP 3 4 5 DUFF 25 GN OFF STATUS RESET 7 1 THERM lt 7 STAT_RE 4 FI THERM VDD 8 50 ag STAT SEL R355 PCLR UEE SU lt AA R362 oe vend 8 25K 047 GND C248 C346 C432 E iu Y arr GO 1000PF T4200PF 1 059 E 1000 5 d 1 POLR 0 9 CKT Ov GATE FIXED O V CIRCUIT R498 t OUT TERM 100 5 MC3423 1 1 44 C419 UCC 0354 98316 SEN1 IND ac 1N5817 SHOTTKY 1 SEN2 REM GND TB1 Figure 6 3 Output 1 2 Board Schematic Diagram sheet 2 of 5 AWWW W 6 9
41. 18 Test oetup other constants which are required to program the supply The following test setup allows access to the components on correctly The model number constant specifies how many the GPIB board and what type of outputs your supply contains and thus a Disconnect the line cord establishes the programming limits for a particular supply b Remove the GPIB board as described in paragraphs 4 3 through 4 6 The MODEL command is used to set the model number and c Place an insulating material on the chassis and lay letter suffix of the supply This was done before your supply the GPIB board on top of the material left the factory However when you replace a defective GP Reconnect all cables in their proper locations IB board or repair an GPIB board by changing its EEPROM e Connectthe line cord chip this setting may be lost and you must set the model number using the MODEL command The GPIB board is connected to the chassis ground with one PC board screw and through the GPIB connector When checking the GPIB board with an oscilloscope be sure that the scope s ground To assign a model number to your supply the following short program can be used with BASIC installed in an GPIB controller Note that in this programming example it is is connected only to a ground point on the GPIB board itself assumed that the GPIB Interface address is 7 and the Connecting the scope ground to any other point on the GPIB supply s GPIB address is 05 and
42. 200MA 9N171 1N645 CR331 33 1901 1098 DIODE SWITCHING 50 200MA 15818 1N4150 CR334 35 1901 0028 DIODE PWR RECT 400V 750MA 04713 CR336 39 NOT USED CR340 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR341 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR342 44 NOT USED CR345 1901 0050 DIODE SWITCHING 80V 200MA 2NS 9N171 1N4150 CR346 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR347 NOT USED CR348 1901 0050 DIODE SWITCHING 80V 200MA 2NS 9N171 1N4150 CR349 1901 0518 DIODE SCHOTTKY SM SIG 71785 5082 2800 CR350 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR351 1901 0050 DIODE SWITCHING 80V 200MA 2NS 9N171 1N4150 CR352 53 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR354 1901 0050 DIODE SWITCHING 80V 200MA 2NS 0562 CR355 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR356 59 1901 0050 DIODE SWITCHING 80V 200MA 2NS 9N171 1N4150 CR360 1901 1080 DIODE SCHOTTKY 20V 1A 04713 1N5817 RELAXED Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No CR361 62 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR363 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR364 70 NOT USED CR371 1901 0050 DIODE SWITCHING 80V 200MA 2NS 9N171 1N4150 CR372 79 NOT USED CR380 81 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 F300 2110 0916 FUSE SUBMINIATURE 7AT 125V 75915 F302 2110 0716 FUSE SUBMINIATURE 5A 125V 75915 F303 2110 0685 FUSE SUBMINIATURE 7A 125V 75915 F304 2110 0713
43. 22 5 250UAC R394 2 6 k COLLECTOR OUT N7CR329 221K RAN NH Ba 4 00 777 BLEED SINK 2 0U 475K C369 aa R408 2A Bd 25 GUARD SENSE 30 gt 4 cs 1 2 ap POV DISABLE Y T j ue 100U gt gt SENSE PP z s BUT 80880 gt TORTUE 05650 R399 HP70 71 116415 1N645 90 9K T 022 5 5 OU GATE 250UAC 1 88 107 FUSE STICK R400 YW W B 1 gt ANN n 9 THERM dii Y 1120 r5 OUT GUARD 10M SHUNT 5x 3 4 5CD 17QW gt gt 10M JTN DRIUE SINK 3 DO PEAK 3 gt 2 3 gt NOFF gt v FEEDBACK R430 po zi F 6 81K 7 0U 100P Ww TB1 z o SENSE DUT TERM CL CONTROL 2 3 5 Ss 00 TERM 3 gt O CV CL CONTROL R433 6 81K C389 R425 7 0U Figure 6 4 Output 3 amp 4 Board Schematic Diagram sheet 4 of 5 6 17 CU DAC 0 TO 10U CC DRC 0 TO 10U SA Bd 3 336K 2A Bd 9 53K 9581 6 CU PRGM 9 5A Bd 625 scs H gt 2A Bd 2 253K 24381 14 5U 9581 I Aw a sc4 16 W 2 6 DGP201 CC PRGM 16 13 CS5 UCC 1 0367 150 5 SCLK 19 QCLK SCLR MSB 13 OE AO DCO Y 7 A SHUNT DROP P O COMP AMP SHUNT DROP COMP 50 C458 0 1 16 500 5A Bd 5 9K UCC 2A Bd 2 1K DC1 SA Bd 15K 11 2A 18 5
44. 29 Short Term Voltage Drift Test This test measures the change in output voltage within the first 30 minutes of a change in the line voltage or the load a Turn off the supply and connect the output to be tested as shown in Figure 3 3 with the load switch closed and the short switch opened Connect the supply to the ac power line through a variable voltage transformer and adjust it for the nominal value b Turn on the supply and select the output to be tested OUTPUT SELECT on front panel c Program the selected output to 50 volts and 0 515 Amps 25W or 1 09 Amps 50W d Adjust the load for 0 5 Amps 25W or 1 Amp 50W as read on the display Check that the CV annunciator is on e Adjust the transformer to 1376 below the nominal line voltage f Wait 30 minutes and record the output voltage value again The difference in the readings taken in steps I and j should be less than 2 millivolts g Adjust the transformer to 6 above the nominal line voltage h Wait 30 minutes and record the output voltage value again The difference in the readings taken in steps f and h should be less than 2 millivolts i Open the load switch and immediately record the output voltage reading j Wait 30 minutes and again record the output voltage reading The difference in the readings taken in steps and j should be less than 2 volts k Repeat steps a through j for each output in your supply 3 30 Short Term Current Drift Test This te
45. 49K 1 125W TF 24546 CT4 1 8 TO 2491 F R420 0683 3305 RESISTOR 33 5 25W CF 19701 CR 25 1 4 5P 33E R421 0698 3449 RESISTOR 28 7K 1 125W TF 24546 CT4 1 8 TO 2872 F R422 0698 8827 RESISTOR 1M 1 125W TF 19701 R423 0757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R424 NOT USED R425 0757 0413 RESISTOR 392 1 125W TF 24546 CT4 1 8 TO 392R F R426 0757 0427 RESISTOR 1 5K 1 125W TF 24546 CT4 1 8 TO 1501 F R427 0698 3444 RESISTOR 316 1 125W TF 24546 CT4 1 8 TO 316R F R428 0757 0405 RESISTOR 162 1 125W TF 24546 CT4 1 8 TO 162R F R429 30 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 681 1 F R431 NOT USED R432 0757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R433 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 681 1 F R434 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R435 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R436 0683 4735 RESISTOR 47K 5 25W CF 19701 CR 25 1 4 5P 47K R437 NOT USED R438 0698 3156 RESISTOR 14 7K 1 125W TF 24546 CT4 1 8 TO 1472 F R439 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R440 41 NOT USED R442 0698 8913 RESISTOR 1 5 1 125W TF 07716 R443 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R444 0757 0447 RESISTOR 16 2K 1 125W TF 24546 R445 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agilent Part Description
46. 6 OUT GUARD 0UT TERM OUT TERM Xz00PF 9380 500 4 0380 E 5 2 CR351 3 2200PF 1 5 2 IL CU CL CONTROL 4 SENSE 200 ANV 2 4 GUN 20K 8 CC PRGM 5 QUT Extr TA ZK 7 SHUNT uzar 2000 5 4 5 Ma N CR353 pate 1N645 R442 5U4 U REF 2 AAA ECT CR353 cz99 C 7 CL CONTROL 16006 ON OFF SK 1K 5 U379 0379 INGE 1000 VOLTAGE LOOP CR348 4 4 3 R446 2 ANN 95K 3 Y CR352 C395 15 8K 0279 7 0U 1N645 4 2 0 20K 015 1000 R435 1K W 2 0U R436 C392 5 V 47 500 7 015 15 4 DO PEAK I 17 44 100U R481 ON OFF m 15 0UT TERM R420 CL LOOP 2 0 4 PRIVE S GUARD 33 5 5A Bd 40K 15 SE 1 44 R472 R454 5A Bd 6 81K AAA SHUNT a AF R473 2A Ba R474 28 GUARD 36 5K 2A Bd ONLY 39 2K C385 SA Bd 10K R477 R475 0402 R421 5 62K Bd CR354 U REF 1 WN ONLY 28 7K Ras 21 5K 82K 5 100PF y NNN CR371 1744 1000 426 C386 V b REMOTE OU TRIP 5 2A Bd 4 R452 B ONLY 1M CL TOGGLE eso SooS ZK CR346 R662 OUT GUARD QUT TERM 1N645 2 4 U REF 8 v 7 0U 0UT TERM 4 98401 100 16 20 E F302 LOOP COLLECTOR OUT 0 54 DRIVE SINK 4 CL CONTROL 4 CL LOOP 2 5 BLEED 2 CIRCUIT E R621 R455 R506 d 15U UNREG AAA i 1 8K 5x 1 1K C428 174W _ C424 d x CR363 WS 500 23 0343 15645 sO 316 4 gt BLEED CONTROL M BLEED SINK A 2N5551 Figure
47. 8 TO 5111 F R665 69 NOT USED R670 0683 1065 RESISTOR 10M 5 25W CC 01121 CB1065 T301 06624 80091 XFMR PULSE 28480 U300 5060 3212 ASSY RGLTR amp HS 28480 U301 5060 3260 IC V RGLTR ADJ NEG 28480 U302 5060 2942 ASSY HS 28480 U303 1826 0527 ASSY HS 27014 LM337T U304 09 NOT USED U310 11 1990 0996 IC OPTO ISOLATOR 28480 HCPL 2220 U312 5080 2128 IC MPU PROGM D 28480 U313 14 1826 1917 IC D A 14 BIT 24355 AD7534KN U315 1826 1590 IC OP AMP PRCN QUAD 10858 LT1014CN U316 17 NOT USED U318 1826 1514 IC V RGLTR V REF FXD 10858 LT1021BCN8 10 U319 1826 1590 IC OP AMP PRCN QUAD 10858 LT1014CN U320 1820 1216 IC DCDR TTL LS 3 TO 8 LINE 3 INP 01295 SN74LS138N U321 1826 1917 IC D A 14 BIT 24355 AD7534KN U322 NOT USED U323 1826 1021 IC ANALOG MULTIPLEXER 17856 DG508ACJ U324 1826 1475 IC COMPARATOR 10858 LT1011CN8 U325 1826 0412 IC COMPARATOR PRCN DUAL 27014 LM393N U326 1810 0639 NETWORK RES DIP 28480 U327 1826 1842 IC ANALOG SPECIAL 28480 U328 33 NOT USED Table 5 7 25W 0 5A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No U334 35 1906 0349 DIODE FW BRDG 200V 6A 71744 KBPC602 U336 1858 0088 TRANSISTOR ARRAY 04713 MPQ7091 U337 1826 1843 04713 TL431IP U338 5060 3567 IC POWER HYBRED 28480 0339 USED 0340 1858 0127 TRANSISTOR ARRAY 56289 TPQA56 U341 45 NOT USED U346 47 1826 1895 10858 LT1001ACN9 U348 1858 0083 TRANSISTOR ARRAY 56289 TPQ6002 U349 NOT
48. 9211 5421 CONTAINER CORRUGATED 28480 06626 90001 MANUAL OPERATING 28480 Miscellaneous 5040 1660 FRONT FRAME 06625 60002 ASSEMBLY FRONT PANEL 6625A 28480 06626 60002 ASSEMBLY FRONT PANEL 6626A 28480 06625 00002 FRONT PANEL LETTERED 6625A 28480 06626 00002 FRONT PANEL LETTERED 6626A 28480 5063 2304 LCD DISPLAY used with through hole GPIB assemblies 28480 5063 3472 LCD DISPLAY used with surface mount GPIB assemblies 28480 1400 0611 CABLE CLAMP REF FRONT PANEL 28480 3101 2862 SWITCH LINE REF FRONT PANEL 28480 5040 5448 WINDOW LCD 28480 Table 5 6A GPIB Board Replaceable Parts surface mount assembly Design Agilent Part No Description Mfg Code Mfg Part No U218 5063 4837 1853 0567 1205 0886 0340 0884 0515 1105 2190 0584 0380 1679 0535 0031 Electrical Parts GPIB Board tested assembly 5063 3471 untested Transistor PNP Note All other electrical parts are surface mounted and are not field repairable Mechanical Parts Heatsink U218 Insulator U218 Screw M3x0 5 U218 2 Lockwasher U218 2 Standoff HEX U218 2 Nut hex w lockwasher J101 2 5 6 Table 5 6 GPIB Through hole Replacement Parts List Design Agilent Part Description Mfg Mfg No Code Part No 201 05 1060 4835 FXD CER 0 1uf 10 50VdC 28480 C206 0180 0374 ELECT 10uf 10 20Vdc 56289 150D
49. CER 16299 C402 0160 7319 CAPACITOR FXD OF MET POLYE D5243 C403 04 NOT USED C405 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C406 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C407 0160 4801 CAPACITOR FXD 100PF 5 100VDC CER 16299 C408 0160 5422 CAPACITOR FXD 047uF 20 50VDC CER 16299 C409 10 NOT USED 411 12 0160 5098 CAPACITOR FXD 22uF 10 50VDC CER 16299 CAC05X7R224J050A C413 0160 7320 CAPACITOR FXD 01uF 10 250VDC D5243 C414 0160 5410 CAPACITOR FXD 3300PF 5 50VDC CER 16299 C415 0160 4048 CAPACITOR FXD 022uF 20 250VAC RMS C0633 C416 0160 7097 CAPACITOR FXD 4 7uF 100V C417 0160 4834 CAPACITOR FXD 047uF 10 100VDC CER 16299 C418 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C419 0180 0291 CAPACITOR FXD 1uF 10 35VDC 56289 150D105X9035A2 C420 0160 4048 CAPACITOR FXD 022uF 20 250VAC RMS C0633 C421 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C422 0160 3969 CAPACITOR FXD 015uF 20 250VAC RMS C0633 C423 0180 0291 CAPACITOR FXD 1uF 10 35VDC 56289 150D105X9035A2 C424 0160 5422 CAPACITOR FXD 047uF 20 50VDC CER 16299 C425 0160 4830 CAPACITOR FXD 2200PF x 10 100VDC CER 16299 C426 0160 4832 CAPACITOR FXD 01uF 1096 100VDC CER 16299 C427 0160 4966 CAPACITOR FXD 1uF 10 100VDC MET POLYC Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No C428 0160 5422 CAPACITOR F
50. CV DAC Buffer U372 6 1 V cm 5 mS cm G DAC s U378 6 U371 6 U362 6 U319 14 8 Bit 1 V Cm 5 mS cm H FET Downprogrammer Q342 Gate 5 V cm 5 mS cm Figure 4 9 Output Board Waveforms During Self Test Exercise Routine DRASTICALLY INCORRECT FRONT PANEL RERDINGS E G 50 25A OR DAC OUTPUTS PROGRAMMING IN A SEVERELY NON LINEAR FASHION MAY INDICATE THAT THE OUTPUT S CALIBRATION CONSTANTS ARE GROSSLY INCORRECT THE DEFAULT CALIBRATION CONSTANTS CAN BE RESTORED TO ALL OUTPUTS AT ONCE BY USING THE MODEL COMMAND SEE PARA 4 91 NOTE THAT USING THIS COMMAND CRUSES ALL OUTPUTS TO BE UNCALIBRATED PREVIOUS TROUBLESHOOTING INDICATED A PROBLEM WITH DAC AMPLIFIER OUTPUT PERFORM THIS TEST TWICE ONCE WITH THE DAC SET TO ZERO AND ONCE WITH THE DAC SET TO FULL SCALE IS PIN 12 TO ISV CHECK PIN C VOLTAGE IT SHOULD BE NERR ZERO WITH DAC SET TO ZERO OR 10 WITH DAC SET TO FULL SCALE INCONCLUSIVE TEST COULD BE LERKY CAP AROUND OP AMP BAD OP AMP OR BAD DAC FEEDBACK RESISTOR IS PIN Cas 12 TO BAD AMP OR OP AMP CAPACITOR Figure 4 10 DAC Amplifier Circuit Troubleshooting 4 36 OVERVOLTAGE IS DISPLAYED AT POWER ON OR WHEN OUTPUT VOLTAGE IS PROGRAMMED BELOW OVERVOLTAGE TRIP POINT THROUGHOUT THIS TROUBLESHOOTING CHART BE SURE THE OUTPUT VOLTAGE AND OVER VOLTAGE ARE SET TO THE VALUES THAT CRUSED OVERVOLTRGE TO BE DISPLRYED CHECK 0327 REFER TO STRTUS INFORM
51. F308 F309 Bias AC Input Fuses 2 A slo blo 2110 0303 F307 NOT USED NOTE The GPIB troubleshooting procedures in this section apply only to earlier through hole board assemblies Surface mount GPIB assemblies are not repairable to the component level If defective the entire GPIB assembly must be replaced Y VOLTAGI W201 STORED IN DISPLAY VOLTAGES J201 GPIB Yy 5V NORMAL RUN nm Zev 33V P204 CONNECTOR POSITION ON P20 5 SIGNAL AC BIAS t2VAC M B J202 W202 NORMAL RUN 5 SIGNAL POSITION Figure 4 2 GPIB Board Fuse and Test Point Locations 4 6 F389 F388 15V LIM 9 Fry ULA 999 15V UNREG 15V 5V VEERE P30 2V Cv LOOP P302 P403 F302 CL LOOP HIGH RAIL CC REF 7 A m 9909009009000 lt 5555555550550 299 une o o 90 5555555 Q 55 JE 05555000 0090000 vin 555000 0999000 vite 9090009 Loon 556556 22909901 uses 15555569 ouo dk MED RRIL LO RRIL U338 V RERDBRCK CL LOOP w PF Figure 4 3 Output Board 1 and 2 Fuse and Test Point Locations 4 14 INITIAL TROUBLESHOOTING AND BOARD ISOLATION PROCEDURES Initial troubleshooting procedures for the power supply are given in the flow chart of Figure 4 5 The procedures first ensure that an ac input failure is not causing the problem and that th
52. FUSE SUBMINIATURE 10A 125V 75915 F305 2110 0916 FUSE SUBMINIATURE 7AT 125V 75915 F307 NOT USED F308 09 2110 0303 FUSE 2A 250V 16428 L300 9140 0129 INDUCTOR RF CH MLD 220UH 5 04072 L301 NOT USED L302 9100 1640 INDUCTOR 160UH 99800 Q300 317 NOT USED Q318 1854 0474 TRANSISTOR NPN SI 04713 2N5551 Q319 1854 0477 TRANSISTOR NPN SI 14433 2N2222A Q320 1855 0665 TRANSISTOR MOSFET 3L585 RFP2N12L Q321 1853 0320 TRANSISTOR Sl 07263 2N4032 Q322 1854 0087 TRANSISTOR NPN SI 03508 Q323 34 NOT USED Q335 1854 0585 TRANSISTOR NPN SI 04713 MJE182 Q336 38 NOT USED Q339 1855 0414 TRANSISTOR J FET 17856 2N4393 Q340 NOT USED Q341 5060 3211 ASSY REG 28480 Q342 1855 0549 TRANSISTOR MOSFET 9 011 IRF512 Q343 1854 0474 TRANSISTOR NPN SI 04713 2N5551 Q344 49 NOT USED Q350 53 1855 0414 TRANSISTOR J FET 17856 2N4393 Q354 1853 0423 TRANSISTOR PNP SI 04713 MPS U 60 R300 01 0686 4725 RESISTOR 4 7K 5 5W CC 01121 EB4725 R302 0811 0610 RESISTOR 56 5 5W PW 01686 R303 0698 8911 RESISTOR 1 3K 1 125W TF 19701 R304 0757 0403 RESISTOR 121 1 96 125W 24546 CT4 1 8 TO 121R F R305 0698 8672 RESISTOR 243 4 1 125W TF 19701 R306 0698 3700 RESISTOR 715 1 125W TF 24546 CT4 1 8 TO 715R F R307 08 8159 0005 RESISTOR ZERO OHMS 72982 R309 0698 8672 RESISTOR 243 4 1 125W TF 19701 R310 0698 0085 RESISTOR 2 61K 1 96 125W TF 24546 CT4 1 8 TO 2611 F R311 0698 4123 RESISTOR 499 1 125W TF 24546 CT4 1 8 TO 499R F R312 0757 0402 RESISTOR 110 1 125W TF 24546 CT4 1 8 TO 111 F R313
53. ON locks out front panel calibration OFF enables front panel calibration As shipped position OFF Switch 3 selects skip self test ON skips self test at turn on OFF enables self test at turn on As shipped position OFF Switch 4 not used Figure 6 2 GPIB Board Component Location
54. TEST BOTH THE OUTPUT VOLTAGE AND CURRENT LIMIT ARE SIMULTANEOUSLY PROGRAMMED TO FULL SCALE VALUES BE SURE THAT NO LOAD OF ANY KIND IS CONNECTED TO THE OUTPUT TERMINALS CHECK FOR SHORT CIRCUIT ON DEFECTIVE LINE S CHECK THAT THE OUTPUT OF THE RERDBRCK DAC RT 362 6 IS AS SHOWN IN FIG 4 9 NO YES CHECK THAT VOLTAGE RT U324 2 IS wa CHECK THAT 0324 7 IS PULSING SEE FIG 4 9 CHECK U324 AND SR LINE U312 Figure 4 8 Sheet 5 Output Board Troubleshooting 4 33 CHECK 0312 SEE TABLE 4 15 U368 6 0319 14 CHECK 0323 SEE PARR 4 29 IF INDIVIDUAL BITS ARE MISSING THE COULD BE DEFECTIVE DAC DEFECTIVE CV U313 CC 1314 U363 OR RERDBRCK U321 TURN SUPPLY OFF REMOVE JUMPER FROM U312 27 INSTALL JUMPER W281 ON THE GPIB BOARD IN THE SKIP SELF TEST POSITION ON P281 TURN_ON SUPPLY GO FIG 4 18 TO CHECK THE DAC AND THE AMPLIFIER Figure 4 8 Sheet 6 Output Board Troubleshooting 4 34 Typical Dataline 17 shown 1 V cm 5 mS cm 8 38 Differental Amplifier U352 6 1 V cm 5 mS cm S Ber E e LLLI LLL C Readback Sign Comparator U324 7 1 V cm 5 mS cm KAMIN WAV WAAAY yV fl a a L NE MER D 4 MHz Oscillator U312 5 1 V cm 0 2 S ecm AC coupled 4 35 E 1 Bypass U338 5 2 Output 5 V cm 5 mS cm F
55. TO ORDER PARTS You can order parts from your local Agilent sales office Refer to the list of sales offices at the back of the manual for the office nearest you When ordering parts include the following information a The Agilent part number b description of the part The quantity desired model number in which the part is used If you wish to order a part directly from the manufacturer locate the manufacturer s Federal Supply Code and corresponding address in Table 5 4 Table 5 2 Reference Designators Blower fan Capacitor Diode Fuse Jack Inductor Plug Transistor Resistor Thermal Resistor Switch Transformer Terminal Block Integrated Circuit Voltage Regulator Zener Diode Wire Oscillator B CR F J L P Q R RT 5 U VR OW Y Table 5 3 Description of Abbreviations ANLG ASSY AWG BAR BLK BNDPOST BOT BRDG CER CHAS COMP CONN CORR CTN CUSHD DAC DBLCHAM DIO EEPROM ELECT EPROM FET FF FW FXD GND GP DHR HS IC IMP INDTR INSUL ISO LCD LED LKWR LS MACHL META METPOL MOD MOS MPU MUXR NMOS OSC PCB PLSTC PNL PROGMD RAM RECT REGIS RES Analog Assembly American Wire Gauge Barrier Block Binding Post Bottom Bridge Ceramic Chassis Carbon Film Composition Connector Corrugated Container Cushioned Digital to Analog Converter Double Chamber Diode Electrically Erasable Program
56. U S A The second part of the serial number is a different sequential number assigned to each instrument If the serial number prefix on your power supply differs from that shown on the title page of this manual a yellow Manual Change sheet that is supplied with the manual add or manual backdating changes in Appendix A of this manual define the differences between your supply and the supply described in this manual The yellow change sheet may also contain information for correcting errors in the manual The serial number prefixes listed on the front of this manual indicate the versions of the supplies that were available when the manual was issued If the serial prefix of your supply is not listed in this manual the manual may include a yellow Manual Changes sheet That sheet updates this manual by defining any differences between the version of your supply and the versions included here and may also include information for correcting any manual errors Note that because not all changes to the product require changes to the manual there may be no update information required for your version of the supply 1 4 FIRMWARE REVISIONS The Read Only Memory ROM chip inside of your supply is identified with a label that specifies the revision of the supply s firmware see paragraph 4 24 Section Il PRINCIPLES OF OPERATION 2 1 INTRODUCTION The following paragraphs provide block diagram level descriptions of the power supplies Di
57. after power is cycled off and on Because the RAM operates faster than the EEPROM at power on the stored data is read into RAM in the system microcomputer via data bus line D7 The EEPROM s 4096 bits of read write memory are divided into 2 pages of 8 X 256 each Each register can be serially read from or written to using data bus line D7 Input data is received via a data latch and output data is sent via a data buffer Data written to the EEPROM is stored in a location until it is updated by a write cycle The CHIP SELECT and CLOCK signals are use by the microprocessor to control the EEPROM s programming modes AT power on the EEPROM signal holds the EEPROM s CLOCK signal off to protect against accidental data writes when power is initially applied 2 20 Front Panel Interface These circuits provide the interface between the supply s system microcomputer and the front panes keyboard and LCD display The microprocessor uses the data latches U210 and data buffers U214 to transfer data between the supply s system microcomputer and the front panel 2 21 Data Latches On the rising edge of the C55 chip select these D type flip flops will be set to the logic states that are present on the data bus lines Data bus lines D2 D7 are fed directly to the front panel display to indicate power supply conditions The LCD display may indicate the output voltage and current for a selected output board the present function being pr
58. and bias supplies The ac input to each output board is rectified filtered and applied to the power module regulator Each output board employs series regulation techniques The regulator element is connected in series with the load and operates in the linear region between saturation and cutoff of the transistor characteristic curve Regulation is achieved by varying the conduction of the series element in response to changes in the line voltage or the load The constant voltage CV control circuit compares the voltage at the output with a reference voltage and generates a control signal which varies the conduction of the series regulator to raise or lower the output voltage as required The constant current CC control 3 1 13 04 934 SIAS 61008 8149 WIE IHA 02408 SUIG IGA DBA b ISMOTIOJ SH TOH HOH3 804 SNOLIHNIGHOO 004308 INALNO S3LON sa RZA ACZ BLA ff 1 AJ 1100819 ANNI 20 Figure 2 1 Agilent 6625A 6626A 6628A 6629A Multiple Output Power Supplies Block Diagram 2 2 25W 0 5A 50W 2A HIGH RANGE VOLTAGE AND HIGH RANGE CURRENT L HIGH RANGE VOLTAGE AND LOW RANGE CURRENT LOW RANGE VOLTAGE AND HIGH RANGE CURRENT LOW RANGE VOLTAGE AND LOW RANGE CURRENT Figure 2 2 Output Operating Ranges for Agilent Models 6625A 6626A 6628A and 6629A Circuit compares the voltage at the current monitor resistor with a reference and likewise vari
59. circuit sends or receives data C50 selects the status monitor part of U327 to send status data back to the microcomputer on data bus lines D0 D5 C51 C54 determine which DAC will receive data CS1 selects the 14 bit CV Constant Voltage DAC CS2 selects the 14 bit CC Constant Current DAC 53 selects the 14 bit Readback DAC and 54 selects the 8 bit OV Over Voltage DAC C55 selects the programming latches U367 and CS6 selects the readback monitor switches U365 U366 and U368 The digital inputs DO D7 to the DAC s are derived from the GPIB controller or from the front panel depending upon whether the supply is in the remote or local mode 2 28 CV DAC The 14 bit CV DAC U313 and amplifier U360 convert the digital input signal from DO D7 supplied through latches U369 into an analog signal CV PROG in the range of 0 to 10 Volts This output signal is used as a reference voltage and is send to the voltage control circuits see paragraph 2 46 to set the output voltage to the programmed value The most significant bits MSB s are loaded into the input register of U313 from the data bus when address line A3 goes high address line A4 goes low and CS1 goes low The least significant bits LSB s are loaded into the input register of U313 from the data bus when address line A3 goes low address line A4 goes high and CS1 goes low The data in the input register in transferred to the DAC of U313 when address line A
60. control circuit compares the output voltage to the programmable reference voltage CV PROG to produce the CV signal As shown in the simplified schematic of Figure 2 6 the major components in the voltage control circuit are unity gain buffer U378 and inverter amplifier U372 output sence buffer U373 who used for 5 guard inverting differential amplifier U352A and CV error amplifier U347 The reference voltage CV PROG 0 to 10 V is applied to U372 which produces a 0 to 10 V signal feeding into the summing junction 51 U347 2 The output voltage is monitored by U352A which produces a 0 to 10 V signal that represents the output voltage magnitude which is also fed into S1 The 0 to 10 V signal is also sent back V READBACK to the secondary interface to indicate the magnitude of the output voltage If the output voltage exceeds the programmed voltage the summing junction goes negative causing U347 U377 to produce a positive going CV control signal For this condition the base drive circuits will conduct more and pull current away from the power module s BASE DRIVE input via the DRIVE input line This will cause the power module s series regulators to conduct less and thus reduce the output voltage HYSTERSIS NOTE POWER 26 9V LIMITING RANGE VOLTAGE AND HIGH RANGE CURRENT MHIGH RANGE VOLTAGE AND LOW RANGE CURRENT BILOW RANGE VOLTAGE AND HIGH RANGE CURRENT LOW RANGE VOLTAGE AND LOW RANGE CURRENT FIG 4 2
61. go high 2 4 V enabling the control circuit and current sources which allow power to reach the output terminals Note that whenever the and turns off the control circuit thus preventing power from reaching the output terminals If the line voltage drops below a minimum level the comparator described above will shut down the output remove power from the output terminals until normal line voltage is restored This resets the microcomputer and sets the output to the turn on state 2 36 Bias Supplies and Precision Reference Voltage The bias supplies U300 U303 generate the voltages required to operate the circuits on the output board The precision reference voltage circuit U318 U319A B C operates from the 15 V bias and generates the VREF outputs 10 V 0 5 which are used by the DAC s and the control circuit 2 10 2 37 Power Mesh and Control Circuits Figure 2 5 The power mesh circuit in the upper half of Figure 2 5 converts the AC from the power transformer to regulated DC output power The primary power control element is the power module hybrid U338 The power mesh circuit generates a constant voltage or constant current output under control of the control circuits shown in the lower half of Figure 2 5 In addition to controlling the power mesh circuit the control circuits send measurement and status data back to the GPIB controller and or front panel via the interface circuits on the output board and the GPIB board
62. indicates that the supply s output is in negative current limit Figure 4 17 shows how this signal is decoded causing CLO pin 10 to go Low 7 00 V pin 17 the 7 00 V bias voltage can range from 7 42 V to 6 48 V CLO pin 18 This open collector output signal takes on the state of the internal CC flip flop when STATUS SELECT pin 11 is Low Figure 4 17 shows the conditions CVO pin 19 This open collector output signal takes on the state of the internal CV flip flop when STATUS SELECT is Low Figure 4 17 shows the conditions that cause CVO to go Low The CV mode is indicated when CVO is Low CVO is CL LOOP pin 20 This input signal when High indicates that the supply s output is in the positive current Limit Figure 4 19 shows how this signal is decoded causing CLO pin 18 to go Low CV LOOP pin 21 When the supply s output is in the CV mode the voltage level of this input signal should fall within the medium level see Table 4 17 A High level at pin 21 indicates that the output is unregulated Figure 4 17 shows how the CV LOOP signal is decoded causing CVO pin 19 to go Low Common pin 22 Along with pin 5 this is a common return for the bias supplies DELAY CAP pin 23 When BIAS TRIP pin 27 is High this signal causes a slow charge of an external delay capacitor toward the DELAY CAP High level which when is Low this signal causes a quick discharge of the external delay capacitor see Fi
63. is specified as the rms or peak to peak output voltage in a frequency range from 20 Hz to 20 MHz This test measures the rms and peak to peak noise on the output a Turn off the supply and connect the output to be tested as shown in Figure 3 3 to an oscilloscope ac coupled between the S and S terminals the Load switch closed and the Short switch opened Be sure to keep the leads from the 50 ohm coaxial cable shield that run to the S and S terminals as short as possible to avoid external noise pickup Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel Program the current and output voltage to the values below ISET lt ch gt lt 0 515 25W or 1 03 50W gt VSET lt ch gt 50 d Adjust the load for 0 5 or 1 Amp as indicated on the front panel display The CV annunciaor on the front panel must be on If it is not adjust the load down slightly e Note that the waveform on the oscilloscope should not exceed 3 mV peak to peak f Disconnect the oscilloscope and connect an rms voltmeter in its place The rms voltage reading should not exceed 500 u V g Repeat steps a through f for each output in your supply 3 16 Transient Recovery Time This test measures the time for the output voltage to recover to within 75 mV following change from 100 mA to 0 5 Amp 25W or 1 Amp 50W Figure 3 4 Transient Recovery Time Test Setup a Turn off the supply and connect the output
64. not to be considered a problem status decoding table which indicates the logic relationship between the five status input lines and the six status output lines is included in Figure 4 17 To troubleshoot status problems set up an oscilloscope as described below and refer to Figure 4 17 and the troubleshooting procedures of Figure 4 18 a Connect oscilloscope Channel at 2 volts div to STATUS SELECT U327 pin 11 b Trigger on Channel A negative slope Set time base to 10 uS div c TheSTATUS SELECT line should go low for about 30 5 During this interval each of the six TTL compatible status output lines from U327 can be checked against the information given in the table on Figure 4 17 by connecting Channel B of the oscilloscope to the IC pin in question d The five status input lines to U327 can also be checked with the scope The input lines should be relatively clean dc waveforms unless there are load transients occurring The input lines are not TTL signals Check Table 4 17 for the voltage values that correspond to a particular input line being High or Low e Follow the procedures outline Figure 4 18 4 49 4 33 Power Module Signals Table 4 18 gives the function and typical signal levels at each pin for a properly operating power module U338 As indicated in the table the voltage levels were measured with the output voltage set to the maximum programmable value with no load connected to the output and
65. period of 90 days from date of delivery During the warranty period Agilent Technologies will at its option either repair or replace products which prove to be defective Agilent does not warrant that the operation of the software firmware or hardware shall be uninterrupted or error free For warranty service with the exception of warranty options this product must be returned to a service facility designated by Agilent Customer shall prepay shipping charges by and shall pay all duty and taxes for products returned to Agilent for warranty service Except for products returned to Customer from another country Agilent shall pay for return of products to Customer Warranty services outside the country of initial purchase are included in Agilent s product price only if Customer pays Agilent international prices defined as destination local currency price or U S or Geneva Export price If Agilent is unable within a reasonable time to repair or replace any product to condition as warranted the Customer shall be entitled to a refund of the purchase price upon return of the product to Agilent LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the Customer Customer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation and maintenance NO OTHER WARRANT
66. supply and connect the output to be tested as shown in Figure 3 3 with the DVM connected across the current monitoring resistor the load switch closed and the short switch opened Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel Program the current of the selected output to the High Range Full Scale Current value and the output voltage to 50 5 volts by sending the following strings ISET lt ch gt lt 0 5 25W or 1 50W gt VSET lt ch gt lt 50 5 gt Adjust the load for High Range Full Scale current and 50 Volts as indicated on the front panel display Check that the CC annunciator is on If it is not adjust the load so the output voltage drops slightly Record the output current reading DVM reading 0 1 Close the short switch and record the output current reading difference in the current readings in steps e and f is the load effect and should not exceed the value listed below for the particular output being tested Qutput CC Load Effect 25W 5 pA 50W 10 A Repeat this test steps a through f for each output in your supply 3 24 CC Source Effect This test measures the change in output current that results when the ac line voltage changes from the minimum to the maximum value within the specifications a b Turn off the supply and connect the ac power line through a variable voltage transformer Connect the output to be tested as shown in Figure 3 3 with
67. the indicated conditions are fully understood and met DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to an Agilent Technologies Sales and Service Office for service and repair to ensure that safety features are maintained Instruments which appear damaged or defective should be made inoperative and secured against unintended operation until they can be repaired by qualified service personnel SAFETY SUMMARY continued GENERAL Any LEDs used in this product are Class 1 LEDs as per IEC 825 1 ENVIRONMENTAL CONDITIONS This instrument is intended for indoor use in an installation category II pollution degree 2 environment It is designed to operate at a maximum relative humidity of 95 and at altitudes of up to 2000 meters Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range SAFETY SYMBOL DEFINITIONS Symbol Description Symbol Description Direct current Terminal for Line conductor on permanently E installed equipment Alternating current Caution risk of electric shock Three phase alternating current Caution refer to accompanying documents Earth ground terminal In position of a bi stable push control Both direct and alternating current N Caution hot surface
68. wait 30 minutes for the output to stabilize f Repeat steps c and d Note the difference between the values read before and after the temperature change The differences in output current should not be more than 240 pA 25W or 1 2 mA 50W The difference between the readback currents should be less than the change in output 265 25W or 1 15 mA 50W Output Current Current Readback TC Spec TC Spec 25W 240 A 265 A 50W 1 2 mA 1 15 mA g Repeat steps a through f for each output in your supply 3 36 Negative Current Limit CC Readback a Repeat steps a through d of paragraph 3 22 b Set the temperature chamber to 30 degrees C and allow 30 minutes for the output to stabilize c Record the negative current limit value DVM reading x 10 Readback the current over the GPIB and record this value e Increase the temperature to degrees C and wait 30 minutes for the output to stabilize f Repeat steps c and d Note the difference between the values read before and after temperature change The differences should not be more than the change I the sink current 265 wA 25W or 1 15 mA 50W 3 37 CV Down Programming Speed This test measures the time required for the output voltage to fall 37 of the High Range Full Scale Voltage time constant Also measured is the time an output takes to change from full scale to zero volts and settle within 50 mV response time 3 12 Turn off the supply and co
69. with the power cable removed To avoid injuries always disconnect power discharge circuits and remove external voltage sources before touching components DO NOT SERVICE OR ADJUST ALONE Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT EXCEED INPUT RATINGS This instrument may be equipped with a line filter to reduce electromagnetic interference and must be connected to a properly grounded receptacle to minimize electric shock hazard Operation at line voltages or frequencies in excess of those stated on the data plate may cause leakage currents in excess of 5 0 mA peak SAFETY SYMBOLS Instruction manual symbol the product will be marked with this symbol when it is necessary for the user to refer to the ZA instruction manual refer to Table of Contents Indicates hazardous voltages Indicate earth ground terminal The WARNING sign denotes a hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in personal injury Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met The CAUTION sign denotes a hazard It calls attention to an operating procedure or the like which if not correctly CAUTION performed or adhered to could result in damage to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until
70. within the limits specified below for the particular output type being tested Prog Accuracy Display Accuracy Output lo DVM Reading 0 1 Front Panel LCD 25W 0 5 A 300 pA Io 280 pA 50W 2A 1 3 mA Io 1 35 mA p Run the program listed in step e Record the value displayed by the controller This value should be within the limits specified below using the Io reading noted in step h Readback Accuracy Output Controller Display 25W Io 280 pA 50W Io 1 35 mA q Repeat steps a through p for each output in your supply 3 22 Negative Constant Current CC Operation This test verifies the readback and display are accurate when the output is in negative current limit operation It also checks that the negative current limit of the 50 watt outputs have two different values depending upon the output voltage a Turn off the supply and connect the output to be tested as shown in Figure 3 6 VOLTMETER OUTPUT POWER SUPPLY 3 V 3A CURRENT MONITOR RESISTOR O Figure 3 6 Negative Current Limit CC Readback Accuracy Set the external power supply to 5V and its current limit to 75 amps fora 25 watt output or 3 amps for a 50 watt output Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel Program the selected output channel to OV by sending the string VSET lt ch gt 0 Divide the voltage drop across the current monitoring resistor by the value 0
71. 024 IC LINE DRIVER LS OCTAL 01295 SN74LS244N U215 1820 1208 IC GATE TTL LS OR QUAD 01295 SN74LS32N U216 1820 2024 IC LINE DRIVER TTL LS OCTAL 01295 SN74LS244N U217 1820 1997 IC FF TTLLS D TYPE 01295 SN74LS374PC 0218 1820 0430 IC 4 8V 5 2V RANGE 27014 LM309K U219 1820 1199 I C INVERTER TTL LS HEX 01295 SN74LS04N U220 1826 0412 IC COMPARATOR PRCN DUAL 27014 LM393N U221 NOT USED U222 1858 0032 XSTR ARRAY 14 PIN PLSTC DIP 27014 LM3146 U230 1818 3921 EEPROM 1 K 28480 0230 1818 4015 NMOS 4096 28480 VR201 1902 1377 DIO ZNR 6 19V 2 PD 4W 28480 Y201 0410 1627 RESONATOR Ceramic 4 0 MHz 28480 GPIB MECHANICAL PARTS 0380 1679 STDF HEX HEAD REF U218 28480 0515 0886 SCR MACH M3X0 5 REF U218 28480 0535 0004 NUT HEX DBL CHAM REF J201 28480 0535 0025 NUT HEX DBL CHAM 28480 06624 60002 LCD ASS Y 28480 1205 0366 HEAT SINK REF U218 28480 2190 0584 WASHER LK HLCL REF J201 2 U218 2 28480 5080 2101 ROM LABEL 28480 9320 4957 LABEL LINE PRINT 28480 1252 0268 CONNECTOR FEMALE 24 CONT 28480 1200 0607 IC SOCKET 16 CONT REF W202 28480 1200 0940 SOCKET STRIP 8 CONT 28480 1251 5240 CONN POST TYPE HDR 20 CONT 28480 1251 8105 CONN POST TYPE HDR 16 CONT 28480 1251 4245 CONN POST TYPE HDR 2 CONT 28480 1251 5385 CONN POST TYPE HDR 4 CONT 28480 1252 1152 OPTION JACK OPTION 750 28480 1258 0189 JUMPER 28480 1251 4787 SHUNT DIP 8 POSIT REF J202 28480 5 8 Table 5 7 25W 0 5A BOARD Replacement Pa
72. 065 RESISTOR 10M 5 5W CC 01121 EB1065 R510 11 NOT USED R512 0683 1065 RESISTOR 10M 5 25W CC 01121 CB1065 R513 NOT USED R514 0698 4435 RESISTOR 2 49K 1 125W TF 24546 CT4 1 8 TO 6811 F R515 0757 0452 RESISTOR 27 4K 1 125W 24546 CT4 1 8 TO 2742 F R516 604 NOT USED R605 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R606 09 NOT USED R610 11 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R612 19 NOT USED R620 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R621 0683 1825 RESISTOR 1 8K 5 25W CF 01121 CB1825 R622 23 NOT USED R624 0698 0087 RESISTOR 316 1 25W TF 24546 NA5 1 8 TO 3160 F R625 NOT USED R626 0757 0465 RESISTOR 100K 196 125W TF 24546 CT4 1 8 TO 1003 F R627 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R628 0757 0465 RESISTOR 100K 1 125W TF 24546 CT4 1 8 TO 1003 F R629 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R630 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R631 0698 4435 RESISTOR 2 49K 1 125W TF 24546 CT4 1 8 TO 2491 F R632 33 0757 0465 RESISTOR 100K 1 125W TF 24546 CT4 1 8 TO 1003 F R634 0757 0200 RESISTOR 5 62K 1 125W TF 24546 CT4 1 8 TO 5621 F R635 0757 0465 RESISTOR 100K 1 125W TF 24546 CT4 1 8 TO 1003 F R636 46 NOT USED R647 0683 6855 RESISTOR 6 8M 5 25W CC 01121 CB6855 R648 59 NOT USED R660 0757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R661 62 0757 0469 RESISTOR 150K 1 125W TF 24546 CT4 1 8 TO 1503 F R663 0
73. 106X9020B2 C207 12 1060 4835 CER 0 1uf 10 50Vdc 28480 C213 1060 4834 FXD CER 0 047uf 10 100Vdc 28480 C214 1060 4808 FXD CER 470pf 5 100Vdc 28480 C215 0180 0405 ELECT 1 8uf 10 20Vdc 56289 1500185 9020 2 216 1060 4835 CER 0 1uf 10 50Vdc 28480 C217 18 1060 4807 FXD ELECT 33pF 100V 5 28480 C219 20 1060 4835 FXD 0 1uf 10 50 28480 C221 1060 4834 CER 0 047 10 100Vdc 28480 C222 0180 3798 CAP 47001 LF 25VDC 28480 C223 25 1060 4835 FXD CER 0 1uf 10 50Vdc 28480 CR201 05 1901 0731 DIODE PWR RECT 400V 1A 28480 F201 2110 0712 FUSE 4A 28480 Q201 1853 0099 TRANSISTOR PNP SI 28480 R201 03 0757 0438 FXD FILM 5 11K 1 1 8W 24546 CT4 1 8 TO 6811 F R204 0698 0083 FXD FILM 1 96K 1 1 8W 24546 CT4 1 8 TO 1961 F R205 0757 0427 FILM 1 5K 1 96 1 8W 24546 CT4 1 8 TO 1501 F R206 0757 0438 FILM 5 11K 1 96 1 8W 24546 CT4 1 8 TO 6811 F R207 0757 0459 FILM 56 2K 1 96 1 8W 24546 CT4 1 8 TO 5622 F R208 0757 0442 FXD FILM 10K 1 1 8W 24546 CT4 1 8 TO 1002 F R209 0757 0449 FXD FILM 20K 1 1 8W 24546 CT4 1 8 TO 2002 F R210 0698 4536 FXD FILM 340K 1 1 8W 28480 R211 0757 0442 FXD FILM 10K 1 1 8W 24546 CT4 1 8 TO 1002 F R212 0698 4440 FXD FILM 3 4K 1 1 8W 24546 CT4 1 8 TO 3401 F R213 0757 0438 FILM 5 11K 1 96 1 8W 24546 CT4 1 8 TO 6811 F R214 0698 3359 FXD FILM 12 7K 1 1 8W 24546 CT4 1 8 TO 1272 F R215 16 0757 0438 FXD FILM 5 11 K 1 1 8W 24546 CT4 1 8
74. 12 DBC1 13 0800 14 20 150 cs WR 602534 UREF 07 RFB D6 05 13 IOUT D4 12 03 11 AGNDS 02 10 01 9 AGNDF 00 8 055 DGND WR AD7534 A1 A0 UREF 07 RFB 06 05 13 IOUT 04 12 05 11 AGNDS 02 10 01 9 AGNDF 00 8 USS DGND UREF A 10U CU DAC 0 TO 10U 1 10U U REF 1 2 3 CC DAC 0 TO 10U ca SU 0323 DG508A R340 5 EN ah FUSE STICK ANN D ses U71 MUX ST 4 2 21K 837 MUX 5 541 sr 89 i AO 55 12 vS a 5 5 as 15194 5611 DAC 0 TO 109 5 aa S25 CC DAC 0 TO 10 is saj ov DAC 0 TO 10U 15U Ur 150 C343 se C344 0 1 0 1 w k 15V 150 R335 C341 C450 15 C355 54429 221K R318 4 4200PF 0 1 150 100U 5 5U 0 10751 C342 0581 z y 921 9 I I i 0 1 0 1 a 500 500 mg 5 11K R336 ANN SA 2 21K TZ STATUS RESET E A POV DISABLE 1 2 QUT ENABLE 5 OU DAC 0 TO 10U 15U C336 0 1 19 500 5 9521 121058 207534 15 aa Sai UREF DCZ 2 DC6 8 4 2105 13 DC 4 i0 13 0 3 11 03 11 AGNOS 12 001 13 02710 01 9 AGNDF 000 14 1400 8 uss DGND 6 15U 20 vec m TE 501 wri 2 D2 KR2x DG 4 05 XFER oo C 16 D
75. 12 pin 23 waveform when attempting reset This line should go high for about 1 5 mS If it does not check U312 Check Check U327 Programming speed will be affected by external output capacitors see paragraph 4 13 in the Operating Manual If problem occurs with no external output capacitor check the voltage programming time constant capacitor C402 in the 0372 CV buffer circuit Check CR347 in the CC loop When not in the CC mode check that U376 6 is approximately 14 volts so that the CC loop will not interfere with up programming Check C393 If unit down programs slowly check U348B R428 CC Circuit U350 and FET Down Programmer Q342 4 50 Table 4 19 Miscellaneous Trouble Symptoms Trouble Symptom Output resets to zero volts Check operation of the medium rail turn on comparator and bias trip low line comparator apparently at random or at U325 If there is an intermittent power transformer connection to the medium rail low line or a blown medium rail fuse a voltage doubler action will take place which will make the medium at heavy load but will appear normal at light and no load In this case the medium rail ripple frequency will equal the line frequency instead of being twice the line frequency as is normal Check medium rail fuses F300 F301 F305 F306 OVERTEMP displayed Check for proper fan operation Check that the power module is screwed down tightly to the heatsink Check volta
76. 14 8159 0005 RESISTOR ZERO OHMS 72982 R315 NOT USED R316 17 0699 0208 RESISTOR 15 25W CF 01121 R318 0757 0284 RESISTOR 150 1 125W TF 24546 CT4 1 8 TO 151 F R319 25 NOT USED R326 27 0757 0424 RESISTOR 1 1K 1 125W TF 24546 CT4 1 8 TO 1101 F 5 21 Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No R328 8159 0005 RESISTOR ZERO OHMS 72982 R329 32 NOT USED R333 0757 0410 RESISTOR 301 1 125W TF 24546 CT4 1 8 TO 301R F R334 NOT USED R335 36 0757 0473 RESISTOR 221K 1 125W TF 28480 CT4 1 8 TO 1003 F R337 38 0757 0438 RESISTOR 5 11K 1 125W TF 24546 CT4 1 8 TO 5111 F R339 8159 0005 RESISTOR ZERO OHMS 28480 R340 0757 0430 RESISTOR 2 21K 1 125W TF 24546 CT4 1 8 TO 2211 F R341 44 NOT USED R345 8159 0005 RESISTOR ZERO OHMS 72982 R346 0698 5579 RESISTOR 5K 5 125W TF 91637 R347 0698 3329 RESISTOR 10K 5 125W TF 03888 PME55 1 8 TO 1002 D R348 0698 6533 RESISTOR 12 5K 1 125W TF 19701 R349 0698 7929 RESISTOR 9 09K 1 125W TF 19701 5033R 1 8 TO 9091 B R350 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R351 0698 4493 RESISTOR 34K 1 125W TF 24546 CT4 1 8 TO 3402 F R352 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 6811 F R353 54 NOT USED R355 0698 3328 RESISTOR 8 25K 5 125W TF 03888 PME55 1 8 TO 8251 D R356 0698 8913 RESISTOR 1 5M 1 125W TF 07716 R357 0699 0489 RESISTOR 16 15K 1 1W TF 19701 R358 0757 0469 RESISTOR 150K 1 125W TF
77. 150 vec cs 0315 WR 02534 A1 A0 VREF D7 RFB D6 05 13 04 12 05 11 AGNDS 02 10 01 9 AGNDF 00 8 USS OGND CU DAC 0 TO 10U 6 150 A 19 20 vec CS 0514 WR 07534 A1 80 UREF 02 RFB 06 05 13 04 12 05 11 AGNDS 02 10 01 9 AGNDF 00 8 DCG 5 D 4 D 3 001 D 0 0 0 19 vec cs 0321 WR 02534 A1 A0 UREF 07 RFB D6 05 13 04 12 03 11 AGNDS 02 10 01 9 AGNDF 00 8 USS OGND 6 V 150 20 VCC DO CS 15V UREF A 15U 10U 10U U REF 1 DAC 0 TO 10U 1 R339 15V 9 15U C337 R335 221K R336 0 Al i FUSE STICK C341 4700PF 100U U I MUX QN VFS DAC 0 TO 10U DAC 0 TO 10U DAC 0 TO 10U 80 55 AL 56 15U 15U 15U 03555 1 550 R337 5 11 33PF 100U 5 NSIS 2 9362 i DC1 D1 WR1 D 2 Da WRe D 3 DC6 14 D 3 XFER lo 04 1 los j Dis DS BYTE2 2 21K STATUS RESET n POV DISABLE 5 4 OUT ENABLE DAC 0 TO 10U D 2 13 D6 8 R 07 U363 DAC0832 OUT1 UREF OUT2 DGND_AGND 10 3
78. 17 SEE FIG 4 17 CHECK U312 FRONT PANEL DISPLAY OR CABLE CHECK U326 U327 OR SHORT ON U32 OUTPUT LINES LOW LINE VOLTRGE CC STATUS MAY BE DUE TO SHORT N OUTPUT WITH SUPPLY OFF CHECK THAT OUTPUT LOOKS LIKE A DIODE CATHODE ON V IN PARALLEL WITH APPROXIMATELY KA Figure 4 18 Status Problems Troubleshooting 4 53 Section V REPLACEABLE PARTS 5 1 INTRODUCTION This section contains information on ordering replacement parts Tables 5 5 through 5 8 list all of the electrical and mechanical components for the power supply Each entry in these tables includes the following information a Reference designator refer to Table 5 2 Agilent part number c Description of part refer to Table 5 3 for abbreviations d Manufacturer s federal supply code number refer to Table 5 4 for manufacturer s name and address e Manufacturer s Part Number Table 5 5 lists the circuit board assemblies cables and electrical components within the chassis of the power supply Table 5 6 lists all of the electrical and mechanical components on the GPIB board This board is identical for all models Table 5 7 lists all of the electrical and mechanical parts on the 25W 0 5 Amp output board Table 5 8 lists all the electrical and mechanical parts on the 50W 2 Amp board The output board configuration for each model is given in Table 5 1 below Table 5 1 Output Board Configuration Model SEE 5 2 HOW
79. 18 CHECK IF CR348 IS CONDUCTING CR348 CONDUCTING INDICATES THAT THE OUTPUT IS IN THE CC MODE CHECK IF ERROR AMPLIFIER INPUT U346 3 IS gt ImV WITH RESPECT TO 0346 2 CHECK R408 U381 0375 R442 CHECK U346 0376 U3 6 MAY BE DEFECTIVE CHECK FOR LEAKY CR341 OR C393 PERK CURRENT LIMIT CIRCUIT CHECK CR348 FOR OPEN Figure 4 8 Sheet 3 Output Board Troubleshooting 4 31 CHECK IF THE OUTPUT CAN SINK CURRENT SEE PARA 3 24 CHECK FET DOWNPROGRAMPER F3G2 0342 P O 53561 CHECK IF THE NEGRTIVE CURRENT LIMIT OPERATES SEE PARA 3 24 SEE FIG 4 20 SUPPLY TO SV AND ITS CURRENT LIMIT TO v 1 5 TIMES THE SCALE CURRENT IS LIMITED TO A 1 1 TIMES THE FULL SCALE CURRENT 55A 25W 2 2A 50H FOR THE SGW OUTPUT ONLY EXTERNAL SUPPLY TO 26V OUTPUTS CHECK IF THE SINK CURRENT IS 551 1 AMPS NOT USED IN 25W CHECK RCROSS HOLES CHECK IF CL ERROR FMPLIFIER Gat BETA RESPECT 0350 2 Figure 4 8 Sheet 4 Output Board Troubleshooting 4 32 TURN OFF THE SUPPLY AND CONNECT NOTES A JUMPER FROM U312 6 S TO LU312 TIMER THIS CONNECTION CAUSES THE UNIT TO GO INTO A TEST LOOP SEE PARA 4 28 AND DISPLAY HDW ERR SEE NOTE TURN ON SUPPLY AND USE SCOPE TO CHECK FOR PULSES RT 312 AND U323 PINS 9 THRU 15 RS SHOWN IN TRBLE 4 15 CHECK 1363 DISCONNECT THE JUMPER AND CYCLE THE LINE VOLTAGE TO RETURN TO NORMAL OPERRTING MODE DURING THIS
80. 2 5 OUTPUT BOARD U212 6 U212 7 INTERFACE U212 8 U212 9 DATA BUFFERS U212 11 U212 12 U212 U212 13 U212 14 U212 15 U212 16 U212 17 U212 18 4 21 Table 4 10 GPIB Board S A Test 5 Description This test checks the GPIB Talker Listener chip U202 bidirectional data bus lines Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer P201 PIN Input START 11 STOP 12 CLOCK 15 GND 4 Measurements Use the data probe to take signatures for each circuit at the input and output pins listed below Circuit Input Signature 5 P201 1 7U39 U201 12 6007 9202 13 183 GPIB U202 14 060U TALKER LISTENER 0202 15 0183 0202 0202 16 0060 Bidirectional Bus U202 17 U202 18 0000 U202 19 0006 4 22 Table 4 11 Board S A Test No 6 Description This test checks the data path from the Microprocessor through Data Buffers U216 to the output of Data Latches U210 in the Front panel Interface circuit Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer Edge P201 PIN Input Setting Connection START 11 STOP 12 CLOCK 19 GND 4 Measurements Use the data probe to take signatures for each circuit at the input and output pins listed below Circuit Input Signature Output Sign
81. 201 14 ARE TTL IMHZ 2 SIGNALS 1 USE FREO COUNTER AND SCOPE TO CHECK Yeal Uee USE SCOPE TO CHECK THE PCLR U222 14 OPTOPON P2 S 3 AND EEPON U222 8 SIGNALS POWER THE PCLR OPTOPON SIGNAL ARE HELD LOW FOR APPROX 0 1 SECOND BEFORE RISING Sv THE EEPON SIGNAL IS HELD LOW FOR 8 1 SECOND THEN BECOMES A PULSE TRRIN AND THEN FLOATS CHECK U228 U22 U222 0281 CHECK THE RAM AND ROM BY MERSURING TIMER ENABLE SIGNAL AT 201 11 CHECK RAM 4287 CHECK ROM U286 Figure 4 6 Sheet 1 GPIB Board and Front Panel Troubleshooting 4 15 FROM SHEET 1 SET UP FOR S A TESTING SEE PARA 4 23 PERFORM S A TESTS 1 THROUGH 8 SEE TABLES 4 6 THROUGH 4 13 CHECK MICROPROCESSOR U2 1 DECODER 968 915 19 CHECK ROM 206 DATA LATCHES 4217 CHECK DATA BUFFERS U216 AND DATA LATCHES U213 IN OUTPUT BOARDS INTERFACE CHECK DATA BUFFERS 0212 IN OUTPUT BOARDS INTERFACE CHECK TALKER LISTENER CHIP U262 S A TEST NO 5 YES NOTE 1 CHECK DATA BUFFERS U216 AND DATA LATCHES U21 IN FRONT PANEL INTERFACE CHECK DATA BUFFERS U214 IN FRONT PANEL INTERFRCE CHECK DATA BUFFERS U214 KEYPAD ON FRONT PANEL SEE TABLE 4 14 FRONT PANEL DISPLAY DOES NOT WORK THE DISPLAY ITSELF IS PROBABLY DEFECTIVE IF ALL TESTS ARE OK BUT THE NOTE 1 GPIB TRANSCEIVERS 203 ARE NOT TESTED CONSEQU
82. 201 18 U201 19 U201 20 U201 21 U201 22 Microprocessor Address Bus Lines U208 15 U208 14 Address Decoder U208 13 U208 U215 U208 12 Chip Select Lines U208 11 U208 10 U215 11 4 18 Table 4 7 GPIB Board S A Test 2 Description This test checks the ROM U206 and the data bus to the output of the Data Latches U217 in the system microcomputer Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer Edge P201 PIN Input Setting Connection START STOP CLOCK GND Measurements Use the data probe to take signatures for each circuit at the output pins listed below These signatures apply to the firmware revisions listed Refer to Appendix A for previous versions Date code gt 2839 2919 2943 2944 3029 3028 Revision gt A 00 00 A 00 01 A 00 00 A 00 02 A 00 01 A 00 03 Part Number gt 06626 06626 5080 06626 5080 06626 80005 80005 2141 80005 2141 80005 Circuit Output Signatures 5 P201 1 0001 U206 11 2H39 U206 12 PAAP ROM U206 U206 13 HHFA Data Bus Lines U206 15 FAUA U206 16 FPFA U206 17 6F1U U206 18 72HU U206 19 7067 U217 2 969H U217 5 7556 U217 System U217 6 PPP4 Microcomputer U217 9 P57F Data Latches U217 12 P764 U217 15 360P U217 16 C96P U217 19 3832 4 19 Table 4 8 GPIB Board S A Test 3 Description This test checks the data path from the Microprocessor th
83. 24546 CT4 1 8 TO 1503 F R359 0699 1211 RESISTOR 95K 1 1W TF 19701 R360 0757 0447 RESISTOR 16 2K 1 125W TF 24546 CT4 1 8 TO 1622 F R361 8159 0005 RESISTOR ZERO OHMS 72982 R362 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R363 64 NOT USED R365 0699 1212 RESISTOR 19K 1 125W TF 91637 R366 0699 1722 RESISTOR 9 75K 1 125W TF 91637 R367 NOT USED R368 8159 0005 RESISTOR ZERO OHMS 20940 R369 71 NOT USED R372 0683 0335 RESISTOR 3 3 5 25W CF 01121 CB33G5 R373 0698 4470 RESISTOR 6 98K 1 125W TF 24546 CT4 1 8 TO 6981 F R374 0757 0452 RESISTOR 27 4K 1 125W TF 24546 CT4 1 8 TO 2742 F R375 0686 2225 RESISTOR 2 2K 5 5W CC 01121 EB2225 R376 0686 4725 RESISTOR 4 7K 5 5W CC 01121 EB4725 R377 0698 4446 RESISTOR 267 1 125W 24546 CT4 1 8 TO 267R F R378 0757 0438 RESISTOR 5 11K 1 125W TF 24546 CT4 1 8 TO 5111 F R379 0698 5347 RESISTOR 495 5 1 125W TF 19701 R380 81 0698 3510 RESISTOR 453 1 125W TF 24546 CT4 1 8 TO 453R F R382 0757 0465 RESISTOR 100K 1 125W TF 24546 CT4 1 8 TO 1003 F R383 84 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R385 0811 1217 RESISTOR 150 5 5W PW 91637 R386 0686 8225 RESISTOR 8 2K 5 5W CC 01121 EB8225 R387 0698 4123 RESISTOR 499 1 125W TF 24546 CT4 1 8 TO 499R F R388 0683 4715 RESISTOR 470 5 25W CF 01121 CB4715 R389 0698 5088 RESISTOR 12K 1 125W TF 24546 CT4 1 8 TO 1202 F R390 NOT USED 5 22 Table 5 8 50W 2A BOARD Replacement Parts List Continued
84. 286 Agilent 0811 1220 Agilent 1901 0719 or 1901 1087 Agilent 0811 1816 Agilent 2100 3272 50 ohm resistor 50 ohm coax or 1 1 probe with RF tip Agilent 0811 0592 Impedance Matching Resistor Figure 3 3 Current Limiting Resistor Figure 3 10 1 ohm 5 watts min Agilent 0811 1340 5 25 Disc 3 5 Disc Agilent 06626 10001 Agilent 06626 10002 Alignment Software 3 2 OUTPUT 2 OUTPUT 1 Agilent 6625A Agilent 6628A OUTPUT 2 OUTPUT 4 OUTPUT 3 OUTPUT 1 Agilent 6626A Agilent 6629A mw aw mensa ww ew _ Figure 3 1 Operating Ranges Available in Agilent Models 6625A 6626A 6628A and 6629A 3 3 being tested It is recommended that the tests be performed in the sequence given and that all data be recorded on the test record provided at the end of the test procedures see paragraph 3 26 3 6 Measurement Techniques 3 7 Setup for All Tests Measure the dc output voltage directly at the S and S terminals of the output under test Connect the output for local sensing and use adequate wire gauge for load leads as described in Section IV of the Operating Manual Many of the test procedures require the use of a variable load resistor capable of dissipating the required power Using a variable load resistor requires that switches be used to connect disconnect and short the load resistor An electronic load if available can be used in place o
85. 3 is high address line A34 is high and CS1 is low CV PROG is also sent to the analog multiplexer so that it can be measured during power on self test U369 and U370 provide isolation between the 8 bit data bus and the CV CC DAC s This isolation assures that signals on the data bus will not be capacitively coupled through the CV and CC DAC s as noise 2 29 CC DAC 14 bit CC DAC 0314 and amplifier U361 convert the digital input signals in a similar manner as the CV DAC into a analog signal CC PROG in the range of 0 to 10 Volts This signal is used as a reference voltage and is sent to the current control circuits see paragraph 2 47 to set output current to the programmed value The most significant bits MSB s are loaded into the input register of U313 from the data bus when address line A3 goes high address line A4 goes low and 5 goes low The least significant bits LSB s are loaded into the input register of U313 from the data bus when address line A3 goes low address line A4 goes high and 52 goes low This data in the input register is transferred to the DAC of U314 when address line A3 is high address line A4 is high and 52 is low CC PROG signal is also sent to the analog multiplexer U323 seo that it can be measured during power on self test 2 30 OV DAC The 8 bit OV DAC U363 and amplifier U319 convert the digital input into an analog signal OV DAC in the range of 0 to 10 Volts This
86. 33 2N2222A Q320 1855 0665 TRANSISTOR MOSFET 3L585 RFP2N12L Q321 1853 0320 TRANSISTOR PNP SI 07263 2N4032 Q322 1854 0087 TRANSISTOR NPN SI 56289 Q323 34 NOT USED Q335 1854 0585 TRANSISTOR NPN SI 04713 MJE182 Q336 38 NOT USED Q339 1855 0414 TRANSISTOR J FET 17856 2N4393 Q340 NOT USED Q341 5060 3211 ASSY RGLTR amp HS 28480 Q342 1855 0549 TRANSISTOR MOSFET 9 011 IRF512 Q343 1854 0474 TRANSISTOR NPN SI 04713 2N5551 Q344 49 NOT USED Q350 53 1855 0414 TRANSISTOR J FET 17856 2N4393 Q354 1853 0423 TRANSISTOR PNP SI 04713 MPS U 60 R300 01 0686 4725 RESISTOR 4 7K 5 5W CC 01121 EB4725 R302 0811 0610 RESISTOR 56 5 5W PW 07088 R303 0698 8911 RESISTOR 1 3K 1 125W TF 19701 R304 0757 0403 RESISTOR 121 1 125W TF 24546 CT4 1 8 TO 121 R F R305 0698 8672 RESISTOR 243 4 1 125W TF 19701 R306 0698 3700 RESISTOR 715 1 125W TF 24547 CT4 1 8 TO 715R F R307 08 8159 0005 RESISTOR ZERO OHMS 72982 R309 0698 8672 RESISTOR 243 4 1 125W TF 19701 R310 0698 0085 RESISTOR 2 61K 1 125W TF 24546 CT4 1 8 TO 2611 F R311 0698 4123 RESISTOR 499 1 125W TF 24546 CT4 1 8 TO 499R F R312 0757 0402 RESISTOR 110 1 125W TF 24546 CT4 1 8 TO 111 F R313 14 8159 0005 RESISTOR ZERO OHMS 72982 R315 NOT USED R316 17 0699 0208 RESISTOR 1 5 25W CF 01121 R318 0757 0284 RESISTOR 150 1 125W TF 24546 CT4 1 8 TO 151 F R319 25 NOT USED R326 27 0757 0424 RESISTOR 1 1K 1 125W TF 100 24546 CT4 1 8 TO 1001 F R328 8159 0005 RESISTOR ZERO OHMS 72982 R329 32 NOT USED R333 0757 0410
87. 35 CAPACITOR FXD 1uF 10 50VDC CER 16299 C337 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C338 40 NOT USED C341 0160 4819 CAPACITOR FXD 2200PF 5 100VDC CER 16299 C342 0160 4835 CAPACITOR FXD 1uF 10 50 VDC CER 96733 C343 44 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 96733 C345 0160 4834 CAPACITOR FXD 047uF 10 100VDC CER 16299 C346 0180 2264 CAPACITOR FXD 3 3UF 5 15VDC TA 56289 150D335X5015A2 C347 50 0160 4835 CAPACITOR FXD 14F 10 50VDC CER 16299 C351 0160 4810 CAPACITOR FXD 330PF 5 100VDC CER 16299 C352 0160 4554 CAPACITOR FXD 01uF 20 50VDC CER 04222 C353 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C354 0160 4822 CAPACITOR FXD 1000PF 5 100VDC CER 16299 C355 0180 0291 CAPACITOR FXD 1uF 10 35VDC TA 56289 150D105X9035A2 C356 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C357 58 NOT USED C359 0160 4831 CAPACITOR FXD 4700 10 100VDC CER 16299 C360 0160 4833 CAPACITOR FXD 022uF 10 100VDC CER 16299 C361 0180 4039 CAPACITOR FXD8200UF 30 10 50VDC AL 19701 C362 0160 4833 CAPACITOR FXD 022uF 10 100VDC CER 16299 C363 0180 4035 CAPACITOR FXD 7400uF 30 10 63VDC AL 19701 C364 0180 4040 CAPACITOR FXD 012F 30 10 35VDC AL 19701 C365 NOT USED C366 0180 0374 CAPACITOR FXD 104F 10 20VDC TA 56289 150D106X9020B2 C367 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 5 9 Table 5 7 25W 0 5A BOARD Replacement Parts List Continued Design Agilent Part Descript
88. 4 3 4 4 4 5 4 6 4 7 4 8 4 9 4 10 4 11 4 12 4 13 4 14 4 15 4 16 4 17 4 18 6 1 6 2 6 2 6 3 6 3 6 4 6 4 LIST OF FIGURES Page Agilent 6625A 6826A 6628A and 6629A Multiple Output Power Supplies Block 2 2 Output Operating Ranges for Agilent Models 6625A 6626A 6628A 6629A _ 2 3 HEP IB Board Block Diagram s c e eo AAA O re e m RD 2 6 Output Board Secondary Interface Circuits Block Diagram 2 9 Output Board Power Mesh and Control Circuits Block 2 12 Voltage and Current Control Circuits Simplified Schematic 2 222 2 13 Typical Output Range Characteristics HH He ee mene eee en ee ne eee 2 14 Typical Downprogramming Characteristics Below 2 0 V sess HH Henne 2 16 Overvoltage Protection Circuits Block Diagram 8 2 17 Operating Ranges Available in Models 6625A 6626A 6820A 6629 3 3 Current Monitoring Resistor Setup res 3 4 Basic Test SETUD za w EIE Ev Oe eee e a ell eret ove OE SY xem EE 3 5 Transient Recovery Time Test Setup ere teret et ee tree rette reet Pon
89. 4 BYTE1 DA BIEN oe 14 Di 15155 D U363 DAC0832 B UREF OUT2 DGND AGND 10 Ts V 0 Figure 6 3 Output 1 2 Board Schematic Diagram sheet 1 of 5 6 8 F308 UNREG BIAS P301 1 lt 2A HSS V 50 75 25500 SZCR301 mee 16500 R302 LM317T 150 022 1009 gt ja CR303 CR302 P301 2 NZ 2 5202 gt gt 7 R301 40208 C304 C311 19 C305 CR304 P301 3 lt 4 7K a eR 5x 73700 0 1 1 215 TA 0 1 2 2 61K 1 A 17 24 500 500 350 350 500 550 350 d d d C315 SEK 0501 a Jen R311 HP34 5 00 0 1 1 T 4 7 1 499 4 7 2200PF 1 24 65 500 550 1 55 550 550 HS347 C308 EXTRA PAD R312 5317 1 R304 R316 FOR 5308 509 110 1 5 121 1 5 5 A 1744 1 44 9303 R314 I 72 0U LM337T 0 R313 ANN B 15U 0 OU DAC 0 TO 10U CR310 1 gt SHUNT DROP COMP 5 COD 4 5 D 0 7 3 16M 15U UNREG 1 OUT ENABLE R358 1 2 4 gt POV DISABLE 402K DA RZ65 5366 50 50 50 5 5 50 50 50 5 50 5 5 50 MED RAIL R359 R361 our TERM 4 gt WN 14 0 14 14 pro 14 Pzo 14 Pzo 14 Pzo 14 14 Pzo 14 Po 14 0
90. 41 8 e 10 e 1206 12515365 32 2 13 12 U215 9219 9208 9202 U280 U203 U283 U212 U214 U282 Sn o 4959 0493 4 P206 DTS ROME k 0 SES ri A EY s 5 4207 NL1251 5385 z 0214 9505 M 8 erar 7 SS 1252 2493 DFS 9382 18 16 9 9 m J207 NL1251 8385 5 Seer 20 44 BRE Pa Oo 4 e 20 8 9 12 13 VCC 8 1252 2493 207 GND 9 NOC n U203 U202 J207 NL1251 5385 45V 204 V 4 7 m 75ALSI60 34 9914 19 o 0213 og 1252 2493 P207 5 2 D108 7 J201 B8 D8 35 2 08 Da 4 Z4ABT574 92 8 m E A 0 295 16 TS ROWS D107 1252 2320 19 8157 DZ DIO7 D1 OE RES e 5 NL1251 5385 wg Lol D106 14 71 pe 4 36 pig po 16 55 11 cp TOSS 1252 2493 P207 DTS 8 Cox8 vec 13 6 5 37 15 DA e NL1251 5385 VCC Qo Do m LEE U282 D105 B5 D5 DIOS D3 3 5 0930 ci EN 1820541 78ALS1085 a 5154 pa 6 38 04 D4 Po Do Qo 1818 6669 11 w HS 1 1Y n 4 7 39 13 5 3 8 Et 4998 pa ZE b A 2 D D103 3 B3 D3 DIO3 D5 D1 1775268 d gt RE 2 2 4 2 8 8 4 Do2 D6 12 Di D2 4 D2 Q2 Z E A0 TEST Q3 D3 3 GS 5 ga 3Y D102 2182 5215 p E 5 E 4 2 4208 NL1251 5385 5 6 p4 13 Gl Salas 9 8 D101 B1 D1 E DIO1 D7 S A D3 E 1252 2493 2 R208 GND e SCL 05 0514 D5 s B n i 4A 4 16 TE TE p4 i 1208 1251 5385 8 5 7 o 9 Ez 9 11 SNT o D5 7 4 5 2 SDA Q6 D6
91. 5 6625A 6628A NOT USED 6626A 6629A 5060 3266 XFMR POWER 50W 2A BIAS W16 06624 80011 FRONT PANEL HARNESS 5 4 Table 5 5 CHASSIS Replacement Parts List continued Design Agilent Part No Description Mfg Mfg Code Part No Chassis Mechanical Electrical 001 0360 2195 BARRIER BLOCK 6 THRMP 2 307 IN L 16428 28480 06624 20007 BARRIER BLK COVER 28480 0360 2310 JUMPER REF BARRIER BLk 28480 0380 0643 STANDOFF HEX 225 IN 28480 0380 1670 SPCR SNAP IN REF DUST COVER 28480 0403 0085 BMNP FT PRS IN 28480 0515 0885 SCR MACH M4X0 7 REF XFMR F P GND 28480 0515 0890 SCR MACH M3X0 5 28480 0515 0897 SCR MACH M3X0 5 28480 0515 0906 SCR MACH M4X0 7 REF SCR U338 28480 0515 0920 SCR MACH M3X0 5 28480 0515 0932 SCR MACH 5 0 8 REF ASSY CHAS XFMR 28480 2190 0421 WASHER FLAT REF U338 28480 0515 1132 SCR MACH M3X0 8 28480 0515 1146 SCR MACH M3X6MM 28480 0535 0023 NUT HEX DB L CRAM 28480 0535 0031 NUT HEX W LKWR 28480 0590 0534 NUT SELF THD REF ASSY FT PNL 28480 06621 80003 LABEL REAR 66254 28480 06624 80009 LABEL REAR 66264 28480 06624 00013 COVER 28480 06626 40001 COVER DUST 28480 06624 00009 CHASSIS MAIN 28480 5040 1672 BUSHING REF U338 28480 06626 40001 DUSTCOVER REF OUTPUT BOARDS 06626 80006 LABLE REF DUSTCOVER 06626 40001 1200 0180 INSULATOR XSTR REF Q321 28480 1200 0181 INSULATOR XSTR NYLON REF 0321 28480 P301 1251 4246 CONN POST TYPE 156 PIN SPCG 3 CONT 28480 1251 810
92. 5 CONN POST TP HDR REF PC ASSY FT PNL 40 28480 P403 1252 1670 CONN POST TYPE 156 PIN SPCG 5 CONT 0077 9 28480 REF0321 1200 0181 INSUL 41 28480 P302 1252 2493 0077 9 42 28480 2110 0269 FSHLDR CLP TYP 25D FUSE REF FC308 9 1306 0 28480 2190 0586 WSHR LK HLCL LW PCBHS 4 0MM REF U338 28480 3050 0893 WSHR FL MTLC FLW REF U338 28480 5001 0539 TRIM SIDE REF CABINET 28480 5041 8801 FEET REF CABINET 28480 5041 8819 CAP STRAP REF CABINET HANDLE 28480 5041 8820 CAP STRAP REF CABINET HANDLE 28480 5060 3221 ASSY WIRE KIT REF PC ASSY FT PNL 28480 5060 3270 CABLE ASSY 28480 5060 3272 CABLE ASSY 28480 5062 3704 STRAP REF CABINET 28480 7120 8214 LABEL WARNING REF U338 28480 9320 5540 LABEL INFO 28480 5 5 Table 5 5 CHASSIS Replaceable Parts List continued Design Agilent Part No Description Mfg Code Mfg Part No Chassis Electrical T1 6626A 9100 4591 TRANSFORMER BIAS POWER 28480 6625A 9100 4720 TRANSFORMER BIAS POWER 28480 2110 0303 FUSE 2A 250V TD FE UL REF F308 9 28480 3160 0092 FINGER GUARD REF COOLING FAN 28480 3160 0097 COOLING FAN 28480 9135 0419 LINE MODULE 28480 CO 5060 3218 CAP ASSY REF LINE MODULE 28480 0160 4259 22 CAP REF 5060 3218 28480 a 2110 0342 LINE FUSE EEE 110V 120V 8A 250VAC 28480 2110 0055 LINE FUSE FOR 220V 240V 4A 250VAC 28480 Chassis Misc 5080 2120 PAD FOAM 28480
93. 546 CT4 1 8 TO 101 F R424 NOT USED R425 0757 0413 RESISTOR 392 1 125W TF 24546 CT4 1 8 TO 392R F R426 0757 0427 RESISTOR 1 5K 1 125W TF 24546 CT4 1 8 TO 1501 F R427 0698 3444 RESISTOR 316 1 125W TF 24546 CT4 1 8 TO 316R F R428 0757 0405 RESISTOR 162 1 125W TF 24546 CT4 1 8 TO 162R F R429 30 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 6811 F R431 NOT USED R432 0757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R433 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 6811 F R434 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R435 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R436 0683 4735 RESISTOR 47K 5 25W CF 19701 25 1 4 5P 47K R437 NOT USED R438 0698 3156 RESISTOR 14 7 1 125W 24546 CT4 1 8 TO 1472 F R439 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R440 41 NOT USED R442 0699 0070 RESISTOR 3 16M 1 125W TF 07716 R443 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R444 0757 0447 RESISTOR 16 2K 1 125W 24546 CT4 1 8 TO 1622 F R445 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R446 0698 4480 RESISTOR 15 8K 1 125W TF 24546 CT4 1 8 TO 1582 F R447 0757 0440 RESISTOR 7 5K 1 125W TF 24546 CT4 1 8 TO 7501 F R448 0757 0469 RESISTOR 150K 1 125W TF 24546 CT4 1 8 TO 1503 F R449 0698 3447 RESISTOR 422 1 125W TF 24546 CT4 1 8 TO 422R F R450 0698 8827 RESISTOR 1M 1 96 125W TF 19701 5 14
94. 6 10 13 12 CONT RS2 D5 Q5 R220 P208 s E3 05 6A 6Y pe 8 3 1252 2493 3 P20 5 0718 0 sf 7 of D Q6 VVV 08 06 1820 5612 A 5206176 15225 or ges o 2 4 2 NL1251 5385 vss u 05 e B 07 DAV 6 GND S 2 NC2 1820 8461 0699 1391 C224 1252 2493 4 P208 DTS 4 1821 0299 V GND I F PN 5 di 10 8 328 cg GND 114 a E e ae r 10 L_ 0 ha ATN 11 NC4 50V FIX OPTO FN AL CONN voc T c 0160 5222 IN ONE PLACE V 283 028 NZ D 0 7 N 73ALS1035 V D 0 7 NC 7 24 0 7 i TA 1Y 5V REN 3 zu m 25 EG R242 5V 2 2Y 20 27 WES ANN E z NBEO WEP A 0 15 W ES A 0 15 10M 5 945 P NDAC T 1W 500 NS 3 74 4A ay 0280 29 pay 32 0699 3819 gt 02 20 5A 5Y 75ALS161 bo 82 5 of 13 EOI 0507 E po 7 es iuri e gt gt De 9 PA RESP FAM 0206 201 uni og 25105 203 44 595 E x 2 REN pos ae z m 12545 vor 13 po Mm 21 4 TAL KIRO 52 2 Soe e 1251 8105 m TE FC iret Fe 21517 a 2 14 Di M 10 0408 5208 I e EXTAL moe xg cs 11 op NRFD NRFDi 35 M2 103115 be TANE TES 95 7 gt 30 pag TXD NZ NDACI 7 7 779 17 pa CE A2 ESX 29 5 2 9 6 5 1 04 25 Aa 8 56 8 598 2 PAL 18 0 Do 00 Log Log DAV m Bl ay vos 8 Da 7 a 28 PD2 p 314 18 IS Ses 7 4
95. 6 4 Output 3 8 4 Board Schematic Diagram sheet 3 of 5 HIGH RAIL CURRENT SOURCES R382 3 100K lt P403 1 2 P378 R381 2R380 453 453 F304 ZA K 108 022 C361 1 i 1 i j NOT USED 8200 F307 5 P403 2 lt 2 nee R373 6 98K P403 3 500 R376 220UH 8 5 1 24 F301 R374 27 4K 0362 TO K 589 ZX CR326 P O 2 ri U34 R386 5262 8 2K 403 4 2 5 R384 12 14 1 2400 1 24 AAV R402 L302 F306 P402 5 4 4 0 160UH me 7 NOT USED 499 R367 R375 UR390 R403 L301 05 2 2K C364 KA p 0 800UH 7A 172W 12000 42 2 R308 er O R409 350 A n E R401 10K a aaa 0238 139 a gt A 3 3 POWER MODULE 2 C376 154 5 HIGH RAIL EMITTER R385 4 2N4032 150 1 MED RAIL BYPASS ae 1 CR332 CR331 0372 5 6 REF 8 2 Ss 8 7 10 5 15 LOW RAIL COLLECTOR BLEED CONTROL R396 2200 7 RA 14 See OUT SENSE AW d 62K NZ CR324 2 11 0 BIAS THERM 15 R410 18 5x 5 ou GATE COMMON C416 C417 R391 1 44 10K CR333 C371 2 43K 74 7 70 1 S 5298 6568 e u 2 22 0375 19 500 500 Q320 20 55 NOT USED ES
96. 64 6628A 66294 WPTV anser Figure 6 1 Power Distribution Schematic sheet 1 of 2 6 3 FOR AGILENT 66264 6629A FOR AGILENT 6625A 6628A SS SS N ey GPIB BOARD SEE 6 2 TO OUTPUT BOARD 1 P302 TO OUTPUT BOARD2 P302 T BOARD FROM 205 LINE MODULE GPIB BOARD P206 ervey Figure 6 1 Power Distribution Schematic sheet 2 of 2 6 4 280 206 M s DI Ma gt 11 Bl Bj Bl Bl z z m a um Uri 5 m R217 R211 226 gp m m RE gt 1705 J207 z BCH Zim mmm s 1111614144 mi Z zu meee meee RZ U220 om EE C235 C232 0000000000000000 oe pum R213 ei P209 P202 ll el je P u202 C209 m _ m mi lt a n 0200 a E 29 m l oll zz ollie 1000000000 QR H BN mm 5 s p ee 8 5 z E E 0225 R228 5 0224 T U282 U285 um gt si j 2 R232 E m rm zii FZI Za mas me vp U215 U219 U208 EN vius m mE PR Sm m ee 088 HE oue E Z scene HI nl oll jas 022 0201 EE N
97. 7 U336 5 5 403 2 lt CR325 R373 C366 z gt Hee Tp A Y 1 20U saseg R388 L300 0340 2 Ge 2 1 44 if t 0 5 5324 6 1009 TPQ5401 0540 t 22 S GC XK R389 Sas 0362 ZNCR326 1P05401 0 2 1000 X 3 CR361 R405 33K 30565 R404 CR340 405 4 400 R402 L302 1 82K AAA P402 5 0 16001 iH a322 NOT USED jos R367 1201 R375 R403 2 2K ese WAM x 0 800UH P 0 1724 12000 NU NU PORE aa gt RADI Qz21 MED RAIL R406 D gt 0538 139 po SOURCE REF 5 POWER MODULE gt il TANN 4 HIGH RAIL EMITTER 5 MA 24205 giro R569 MED RAIL BYPASS N CR318 L t wr CR362 CR332 CR331 C372 sx 6 8 A 5 31 00 RAIL COLLECTOR Bd 75 5 5 3 BASE DRIVE OUTPUT R407 EH BEEED CONTROL 5596 220002 555 RIE DUT SENSE 5 5 62K NZ CR327 S ZCR324 x s Bias THERM S R411 R410 18 5 CR333 R395 Sx OU GATE COMMON 5 0416 0412 ANN 1 44 ZK 5 10K C371 2 43K CR328 3 7 047 Cz68 1000 1000 je 0375 C420 0 7 0U R390 207 29 7022 100 42 5 250VAC A Rz94 3 U COLLECTOR OUT USED RSS ddcAvon GUARD SENSE BLEED SINK 475K 3 0369 Beet R408 2A Bd 25 FA 5 POV DISABLE 022 K F303 2 ANN i 1 2 4 V 1000 eau 3 2 09 SENSE gt 7A Ax GUARD CO ee CR330 R399 HP70 C415 1N645 A OU GATE 250UAC 1724 10 3 4 FUSE STICK YW 5x buc SHUNT val E 10M JTN 2 DRIVE SINK PEAK
98. 75 Check regulation of bias supply 3 pin regulators as a function of line voltage Check the stability of the 10 V reference voltages Check if the output has been properly calibrated If current readback error check U319 U345 U323 See paragraph 4 28 If current readback as well as current accuracy are incorrect by approximately the same percentage check sense resistor R408 If in the 50 V range only CHECK VFS input U323 If in other voltage or current ranges check U365 U366 U315 U382 See Table for switch closures Check for proper operation of FET Q339 and transistor U348A Check for slow turn on of Q319 as controlled by C371 Check for leaky current sources U336 U340D boards by shorting U327 23 delay cap to common to turn off Q319 and Q318 The voltage on each of R379 R381 should be less than 2 millivolts Check that the OV setting is accurate properly calibrated Check that the OV setting is not too close to the sum of the sense lead voltage plus the load lead drop Note that the overvoltage circuit senses the output voltage at the V and V output terminals not at the sense leads Check for open C437 in the sense protect circuit Check for open C429 C359 Check for excessive load lead voltage drop see paragraph 4 5 in the Operating Manual See Poor Transient Response symptom in this table Check output with an oscilloscope The overvoltage circuit may be resetting and then tripping again Check FET Q320 Check U3
99. 757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R664 0757 0438 RESISTOR 5 11K 1 125W TF 24546 CT4 1 8 TO 51 11 F R665 69 NOT USED R670 0683 1065 RESISTOR 10M 5 25W CC 01121 CB1065 T301 06624 80091 XFMR PULSE 28480 U300 5060 3212 ASSY RGLTR amp HS 28480 U301 5060 3260 IC V RGLTR A 28480 U302 5060 2942 ASSY HS 28480 U303 1826 0527 ASSY HS U304 09 NOT USED U310 11 1990 0996 IC OPTO ISOLATOR 28480 HCPL 2200 U312 NOT USED 0313 14 1826 1917 IC D A 14 BIT 24355 AD7534KN U315 1826 1590 IC OP AMP PRON QUAD 10858 LT1014CN U316 17 NOT USED U318 1826 1514 IC V RGLTR V REF FXD 9 95 10 05V 10858 LT1021BCN8 10 U319 1826 1590 IC OP AMP PRON QUAD 10858 LT1014CN U320 1820 1216 IC DCDR TTL LS 3 TO 8 LINZE 14INP 01295 SN74LS138N U321 1826 1917 IC D A 14 BIT 24355 AD7534KN U322 NOT USED U323 1826 1021 IC ANALOG MULTIPLEXER CHNL 17856 DC508ACJ Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No U324 1826 1475 IC COMPARATOR CP 10858 LT1011CN8 U325 1826 0412 IC COMPARATOR PRON DUAL 27014 LM393N U326 1810 039 NETWORK RES 01121 U327 1826 1842 IC ANALOG SPECIAL U328 33 NOT USED U334 35 1906 0349 DIODE FW BRDG 200V 6A 71744 KBP0602 U336 1858 0088 TRANSISTOR ARRAY 04713 7091 0337 1826 1843 04713 TL431IP U338 5060 3567 IC POWER HYBRED 28480 0339 USED 0340 1858 0127 TRANSISTOR ARRAY 56289 TPQA56 U341 45 NOT USED U346 47 1826 1895 10858 LT1001ACN8
100. 8 1 BLT 8 n 2 HBON bl Elbe Od 1 MOB B X MB 8 X an Ni amp T 5 DDH tem 8 KAAR 2 asl siel ald ETH 24 64 ws ELA 4 Figure 2 3 GPIB Board block diagram 2 6 2 24 OUTPUT BOARD The following paragraphs provide block diagram level descriptions of the output board The descriptions cover the two output board types Differences between the board types are given as required Figure 2 1 shows which output board types are used in the power supplies The descriptions that follow are divided into two main block diagram discussions Secondary Interface Circuits and Control Circuits The block diagrams illustrate the major circuits and signal flow on an output board Complete circuit details are shown on the output board functional schematic Figure 6 3 in the rear of the manual The functional names on the block diagrams correspond with those on the functional schematic 2 25 Secondary Interface Circuits Figure 2 4 These circuits receive digital signals from the GPIB board and convert them to analog signals voltages which are sent to the power mesh and control circuits to program the output voltage output current and overvoltage Measurement and status signals are sent back to the secondary interface circuits from the power mesh and contro
101. 8 25 WATT 5A FIG 4 2B 50 WATT 2A QUADRANT QUADRANT 2 1 SEAT QUADRANT 4 CV OR OPERATION CURRENT SINK OPERATION CV OR REVERSE DIODE CHARACTERISTIC QUADRANT QUADRANT 2 QUADRANT 4 Figure 2 7 Typical Output Range Characteristics 2 14 If the output voltage is less than the programmed voltage the junction goes positive causing U347 377 to produce a negative going CV control signal For this condition the base drive circuit will conduct less allowing more current to flow into the BASE DRIVE input This will cause the power module s series regulator to conduct more and thus increase the output voltage 2 47 Current Control Circuit When the output is operating in the constant current mode this circuit generates the CL control and the CL LOOP signals Cl control signal is applies through OR gate diode CR348 to control the base drive circuit in order to regulate the output current The CL LOOP signal is sent back to the secondary interface circuit to indicate that the output is in the constant current mode of operation The current control circuit compares the output current to a programmable reference voltage CC PROG This comparison produces the CL control signal In order to make this comparison the circuit monitors the voltage SHUNT across current monitoring resistor R408 This voltage drop is proportional to the amount of output current The SHUNT and PRO
102. 8 TO 1002 F R484 86 NOT USED R487 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R488 0757 0460 RESISTOR 61 9K 1 125W TF 24546 CT4 1 8 TO 6192 F R489 90 0686 1065 RESISTOR 10M 5 5W CC 01121 1065 R491 0683 0475 RESISTOR 4 7 5 25W CF 01121 CB47G5 R492 0683 2225 RESISTOR 2 2K 5 25W CF 19701 CR 25 R493 0757 0430 RESISTOR 2 21K 1 125W TF 24546 CT4 1 8 TO 2211 F R494 0698 3430 RESISTOR 21 5 1 125W TF 03888 PME55 R495 0757 0447 RESISTOR 16 2K 1 125W TF 24546 CT4 1 8 TO 1622 F R496 0757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R497 0683 3915 RESISTOR 390 5 25W CF 01121 CB3915 R498 0683 1015 RESISTOR 100 5 25W CF 01121 CB1015 R499 0698 4493 RESISTOR 34K 1 125W TF 24546 CT4 1 8 TO 3403 F R500 01 0757 0404 RESISTOR 130 1 125W TF 24546 CT4 1 8 TO 131 F R502 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R503 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R504 0683 1035 RESISTOR 10K 5 25W CF 01121 CB1035 R505 NOT USED R506 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R507 0683 0475 RESISTOR 4 7 5 25W CF 01121 CB47G5 R508 09 0686 1065 RESISTOR 10M 5 5W CC 01121 EB1065 R510 11 NOT USED R512 0683 1065 RESISTOR 10M 5 25W CC 01121 CB1065 R513 NOT USED R514 0698 4435 RESISTOR 2 49K 1 125W TF 24546 CT4 1 8 TO 6811 F R515 0757 0452 RESISTOR 27 4K 1 125W TF 24546 CT4 1 8 TO 2742 F Table 5 7 25W 0 5A BOARD Replacement Pa
103. 9 1375 3 0699 1385 VN 88 moz fe 50V FIX NL0160 6222 B R211 R229 UNREG d e ANN e Vv 10K 511K C SCREW M3 P BIAS COM 0699 1391 0699 1385 Figure 6 2 GPIB Board Schematic Diagram 6 6 C436 E B VR Lo HR412 Le R471Fe C427 O Le C418 R C396 Q339 0000 0000 beeen G R489 O C420 nie e R493l o H C419 o jo Ml 0000 0000 4 m OO O 5452 O 0353 P NEN B gsvJr e o 80rd 8 Dooooooo ooooooo i P 5 5000000 T o 525 185261 23241 LU D 000000 e jcsssre 6103539 1 3 o9zn 5 1 04 lt 692n o nooooooooo Q 0000000000
104. B835 R476 0699 0088 RESISTOR 1 21M 1 125W TF 19701 R477 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R478 82 NOT USED R483 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R484 86 NOT USED R487 0757 0442 RESISTOR 10K 1 125W 24546 CT4 1 8 TO 1002 F R488 0757 0460 RESISTOR 61 9K 1 125W TF 24546 CT4 1 8 TO 6192 F R489 90 0686 1065 RESISTOR 10M 5 5W CC 01121 EB 1065 R491 0683 0475 RESISTOR 4 7 5 25W CF 01121 CB47G5 R492 0683 2225 RESISTOR 2 2K 5 25W CF 19701 CB2225 R493 0757 0430 RESISTOR 2 21K 1 125W TF 24546 CT4 1 8 TO 2211 F R494 0698 3430 RESISTOR 21 5 1 125W TF 03888 PME55 1 8 TO 21 R5 F R495 0757 0447 RESISTOR 16 2K 1 125W TF 24546 CT4 1 8 TO 1622 F R496 0757 0401 RESISTOR 100 1 125W TF 24546 CT4 1 8 TO 101 F R497 0683 3915 RESISTOR 390 5 25W CF 19701 CR 25 1 4 5P 390E R498 0683 1015 RESISTOR 100 5 25W CF 01121 CB1015 R499 0698 4493 RESISTOR 34K 1 125W TF 24546 CT4 1 8 TO 3402 F R500 01 0757 0404 RESISTOR 130 1 125W TF 24546 CT4 1 8 TO 131 F R502 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R503 0757 0199 RESISTOR 21 5K 1 125W TF 24546 R504 0683 1035 RESISTOR 10K 5 25W CF 01121 CB1035 R505 NOT USED R506 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R507 0683 0475 RESISTOR 4 7 5 25W CF 01121 CB47G5 5 24 Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No R508 09 0686 1
105. C U313 U360 on the specified output board probably failed Perform the output board troubleshooting procedures see paragraph 4 25 The current DAC U314 U361 on the specified output board probably failed Perform the output board troubleshooting procedures see paragraph 4 25 The overvoltage OV DAC U363 U319D on the specified output board probably failed Perform the output board troubleshooting procedures see paragraph 4 25 The output return fuse F303 on the specified output board is opened If error occurs again after fuse has been replaced the power module on the output board may be defective Perform the output board troubleshooting procedures see paragraph 4 25 The specified output board failed the GPIB board is defective or the cabling between the output board and GPIB board is defective Follow the board isolation procedures outlined in Figure 4 5 If all three messages appear the readback circuit is probably defective 4 9 Table 4 5 ERROR Codes and Messages Message Error Code E ERR key ERR query Explanation and Remedy Programming Errors NO ERROR INVALID CHAR INVALID NUM INVALID STR SYNTAX ERROR NUMBER RANGE NO OUERY DISP LENGTH BUFFER FULL Hardware Errors EEPROM ERROR HARDWARE ERR HDW ERR CH 1 HDW ERR 2 HDW ERR CH 3 HDW ERR CH 4 NO MODEL NUM UNCALIBRATED SKIP SLF TST Errors that can occur while attempting calibration CAL ERROR Indicates there
106. C409 0160 4822 CAPACITOR FXD 1000PF 5 100VDC CER 16299 C410 NOT USED 411 12 0160 5098 CAPACITOR FXD 22uF 10 50VDC CER 16299 CAC05X7R224J050A C413 0160 7320 CAPACITOR FXD 01uF 10 250VDC D5243 C414 0160 5410 CAPACITOR FXD 3300PF 5 50VDC CER 16299 C415 0160 4048 CAPACITOR FXD 022uF 20 250VAC RMS C0633 C416 0160 7097 CAPACITOR FXD 4 74F 100V C417 0160 4834 CAPACITOR FXD 047uF 10 100VDC CER 16299 C418 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C419 0180 0291 CAPACITOR FXD 1uF 10 35VDC TA 56289 150D105X9035A2 420 0160 4048 CAPACITOR FXD 022uF 20 250VAC RMS C0633 421 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C422 0160 3969 CAPACITOR FXD 015uF 20 250VAC RMS C0633 C423 0180 0291 CAPACITOR FXD 1uF 10 35VDC TA 56289 150D105X9035A2 C424 0160 5422 CAPACITOR FXD 047uF 20 50VDC CER 16299 C425 0160 4830 CAPACITOR FXD 2200PF 10 100VDC CER 16299 C426 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C427 0160 4966 CAPACITOR FXD 1uF 10 100VDC MET POLYC 28480 C428 0160 5422 CAPACITOR FXD 047uF 20 50VDC CER 16299 C429 0160 5098 CAPACITOR FXD 22 10 50VDC CER 16299 CAC05X7R224J050A Table 5 7 25W 0 5A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No C430 31 NOT USED C432 0160 4822 CAPACITOR FXD 1000PF 5 100VDC CER 16299 C433 0160 4791 CAPACITOR FXD 10PF 5 100VDC CER 16299 C434 35 NOT USED C436 0160 6999 CAPAC
107. D 25W 7V 2 6 mV DVM 3 1 mV 50W 16 V 45 5 mV DVM 6 mV Run the program listed in step e Record the value displayed bye the controller This value should be within the limits specified below Readback Accuracy Output Controller Display 25W DVM 3 12 mV 50W DVM 6 06mV Select the high voltage range using the range command VSET lt ch gt 50 Or Press range and volt buttons Program the selected output channel to zero volts by sending the string VSET lt ch gt 0 Record the output voltage readings on the digital voltmeter DVM and the front panel display The readings should be within the limits specified below Also note that the display indicates the output current and the CV RMT and ADDR annunciators are on Note that the output current reading is approximately zero because there is no load connected Prog Accuracy Display Accuracy DVM Reading Front Panel LCD 10 mV DVM 10 mV Read back the output voltage from the selected channel over the GPIB by running the program from step e Record the value displayed on the controller This value should be within the DVM reading noted in step 1 10 mV Program the selected output s voltage to 50 V by sending the following string VSET ch 50 Record the output voltage readings on the DVM and the front panel display The readings should be within the limits specified below Prog Accuracy Display Accuracy DVM Reading Front Panel LCD 50 V 18 m
108. E 1355 OR U327 CHECK XFMR BIAS CABLE F388 AND F389 OBSERVE THAT AT 9 REMOVE ZERO OHM RESISTORS R307 S HELD LOW FOR R3 8 R313 R314 CHECK ALL FOUR BIAS VOLTAGES CHECK U312 U327 C346 SEE FIGURE 4 16 CHECK REGURLTORS U3 U3 3 CONNECT A JUMPER BETWEEN P3G2 1 AND P3 2 2 AND OBSERVE PULSES REPLACE ALL ZERO OH RESISTORS aree er TO PERSURE PROBLEM BIAS OUTPUT CURRENT TYPICAL AND CURRENT VALUES ARE LISTED IN THE TABLE ON SHEET 1 CHECK U318 ALSO CHECK U312 21 FOR SHORT EXCESSIVE CHECK REGULATOR AND ASSOCIATED CURRENT CIRCUITRY YES REMOVE JUMPER FROM P3 2 1 AND P302 2 USE LOW CAPACITANCE PRODE X1 PROBE AND SCOPE TO CHECK CLOCK SIGNAL RT U312 4 AND U312 5 IT SHOULD BE CHECK EXTERNAL CIRCUITS FOR s 2 5 RT 4MHZ SHORTS OR OVERLORDS SEE FIGURE 4 9 CHECK Y388 C324 U312 Figure 4 8 Sheet 2 Output Board Troubleshooting 4 30 CHECK IF THE OUTPUT VOLTAGE PROGRAMS PROPERLY SEE PARA 3 12 CHECK IF THE CURRENT LIMIT OPERRTES PROPERLY SEE PARA 3 21 PROGRAM CURRENT TO FULL SCALE AND CHECK OUTPUT OF CC DAC CIRCUIT AT U371 6 TURN SUPPLY OFF AND CONNECT A SQ OHM 1 W LORD ACROSS THE V AND OUTPUT TERMINALS TURN SUPPLY ON AND PROGRAM VOLTAGE 15 NOTE THAT CURRENT 15 PROGRAMMED TO ZERO AT TURN ON AND OUTPUT SHOULD NOW BE IN CURRENT LIMIT CHECK OUTPUT DAC CIRCUIT RT 0371 5 TROUBLESHOOT THE CC DAC CIRCUIT SEE FIG 4
109. EE 17 15 UBB 2 0 GND Ez 0350 0349 c346 c432 359 GND s e Ee e 714200 1 500 500 500 500 150 1000 1000 PCLR 4 CO W 0 V CKT 09 GATE CR357 FIXED 0 CIRCUIT R500 CR356 R501 CR358 R496 ANA ANN Km a 130 C426 130 100 1 1 44 R492 0419 UCC 2 2K 1900 0354 NASZE 5x 1 R515 SEN1 IND 1 4W 35U R502 27 4K 8 10M _ JTN x I OUT 5 5x TB1 OU i R494 05560 CR359 R495 R497 R514 REMIS 5459 o GND 16 2K 390 5 22 C418 R493 21 5 1N5817 Ai 2 49K 549 ZNS OU 2 21K SHOTTKY Figure 6 4 Output 3 8 4 Board Schematic Diagram sheet 2 of 5 AWWW W 0451 U READBACK 5 0354 0350 0 1 4 SOURCE REF 500 i 15U R448 HIGH RAIL R624 MJE350 2N4303 D 150 150K 42 AN py d g N4l5 3 4 SENSE 90379 EMT 2 ON OFF U380 10K 1 R471 3 4 E CU FEEDBACK U REF 2 4 Te R487 EY 2 CV PRGM Es 10K Q351 S R491 LR509 6 499 gt R488 42 10M 61 9K X 1 4 DRC BUFFER 1 4 1 44 2N4393 0 C414
110. ENTLY IF S A TEST 5 IS OK BUT YOU CANNOT PROGRAM OVER THE GPIB U283 OR Uege IS PROBRBLY DEFECTIVE Figure 4 6 Sheet 2 GPIB Board and Front Panel Troubleshooting and Board Isolation 4 16 o 9 9595559 9 9 92914 JE 4 gt 5 00000000085 00000000 Bo 210 P209 B rel H 9 C 0000000008 5 NOP_POSITION NORMAL RUN POSITION SIGNATURE ANALYSIS SA PINS AND 4 ON 205 208 JUMPER PACK W202 JUMPER PACK W202 IS POSITION ARE SHORTED FOR S A TESTS IS INSTALLED IN J203 J202 INSTALLED IN J202 FOR JUMPER W201 IS INSTALLED SEE FIG 4 8A FOR S A TESTS 1 AND 2 SA TESTS 3 THROUGH 8 BETWEEN 201 5 AND P201 6 P295 206 207 208 CONNECTOR DETAIL PC BOARD CONNECTOR Figure 4 7 GPIB Signature Analysis Test Setup 4 17 Table 4 6 GPIB Board S A Test 1 Description This test checks Microprocessor U201 address lines AO A15 and Address Decoder U208 215 chip select lines CS1 CS8 Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer P201 PIN Input i Connection START 9 STOP 10 CLOCK 13 GND 4 Measurements Use the data probe to take signatures for each key at the output pins listed below Circuit Signature 5 0003 U201 9 U201 19 U201 11 U201 12 U201 13 U201 14 U201 15 U201 16 U201 17 U
111. F 5 100VDC CER 16299 C338 40 NOT USED C341 0160 4819 CAPACITOR FXD 2200PF 5 100VDC CER 16299 C342 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 96733 C343 44 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C345 0160 4834 CAPACITOR FXD 047uF 10 100VDC CER 16299 C346 0180 2264 CAPACITOR FXD 9 3 5 15VDC TA 56289 150D335X5015A2 C347 50 0160 4835 CAPACITOR FXD 1uF 10 50 VDC CER 16299 C351 0160 4810 CAPACITOR FXD 330PF 5 100VDC CER 16299 C352 0160 4554 CAPACITOR FXD 01uF 20 50VDC CER 04222 C353 0160 4835 CAPACITOR FXD 1uF 10 50 VDC CER 16299 C354 0160 4822 CAPACITOR FXD 1000PF 5 100VDC CER 16299 C355 0180 0291 CAPACITOR FXD 1uF 10 20VDC TA 56289 1500105 9035 2 C356 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C357 58 NOT USED C359 0160 4831 CAPACITOR FXD 4700PF 10 100VDC CER 16299 C360 0160 4833 CAPACITOR FXD 022uF 10 100VDC CER 16299 C361 0180 4039 CAPACITOR FXD 8200uF 30 10 50VDC AL 56289 C362 0160 4833 CAPACITOR FXD 022uF 10 100VDC CER 16299 C363 0180 4035 CAPACITOR FXD 7400uF 30 10 50VDC AL 56289 C364 0180 4040 CAPACITOR FXD 012F 30 10 35VDC AL 56289 C365 NOT USED C366 0180 0374 CAPACITOR FXD 10uF 10 20VDC TA 56289 150D106X9020B2 C367 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C368 0180 0393 CAPACITOR FXD 39uF 10 10VDG TA 56289 150D396X9010B2 Table 5 8 50W 2A BOARD Replacement Parts List Continued Design Agile
112. FF PCLR BIAS TRIP 15V Output Output Input Bias 1 Signal levels are referenced to common 2 Indicates that the stated voltage threshold depends upon the value of the 7 V nominal supply For example if the value of the 7 V supply is actually 7 1 V 0 1 V lower than 7 V then the LOW value given fro pin 25 would read 6 8 V which is LOW AND HIGH LEVELS 0 10 mV lt 0 4 V lt 1 3 V 0 2 lt 0 4 V lt 0 4 V lt 0 4 V lt 0 4 V 2 6 0 4 V 2 5 V 0 15 V 1 0 4 V 0 8 V 0 3 V 1 lt 4 4 V 0 25 V 1 50 10 mV gt 2 4 V gt 1 95 V 0 25 V t gt 8 Vor gt 11V gt 2 4 V gt 2 4 V gt 2 4 V gt 2 4 V gt 2 4 V gt 2 6 V 0 4 V gt 2 8 V 0 3 V t gt 2 4V gt 0 85 V 0 25 V t gt 4 2 V 0 25 V LOW lt 4 4 V 0 25 V 1 MEDIUM gt 4 2 0 25 V 1 or gt 0 85 V 40 25 1 HIGH gt 0 95 V 40 25 V t lt 6 7 V 1 3 V lt 0 4 V lt 6 7 V lt 0 8 V lt 0 3 V gt 6 7 V 1 3 V gt 2 4 V gt 1 7 V gt 2 4 V gt 0 85 V 0 2 V 0 1 V lower than 6 7 V See OV DRIVE pin6 description in paragraph 4 30 Minus one diode drop gt W MIN amp MAX DC PIN VOLTAGES ON A PROPERLY OPERATING BOARD 2 35 V 6 5 7 42 0 6 08 V 75 V OV 7 42 Indicates that hysteresis is involved in the trip voltage level and a transition from a lower voltage up to the ind
113. FXD 022uF 10 100VDC CER 16299 C301 0180 3801 CAPACITOR FXD 1800 30 10 63VDC AL 19701 C302 0180 3799 CAPACITOR FXD 2700 30 10 50VDC AL 19701 C303 04 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C305 0180 0291 CAPACITOR FXD 1uF 10 35VDC 56289 150D105X9035A2 C306 0180 0100 CAPACITOR FXD 4 7uF 10 35VDC 56289 150D475X9035 B2 C307 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C309 0180 0291 CAPACITOR FXD 1uF 10 35VDC 56289 150D105X9035A2 C310 0180 0100 CAPACITOR FXD 4 7 10 35VDC TA 56289 150D475X9035B2 C311 14 0180 0291 CAPACITOR FXD 1uF 10 35VDC 56289 150D105X9035A2 C315 0160 4281 CAPACITOR FXD 2200PF 20 250VAC RMS C0633 PME271Y422 C316 19 NOT USED C320 0160 4800 CAPACITOR FXD 120PF 5 100VDC CER 16299 C321 22 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C323 0160 4800 CAPACITOR FXD 120PF x 596 100VDC CER 16299 C324 0160 4787 CAPACITOR FXD 22PF x 5 100VDC CER 16299 C325 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C326 0160 4807 CAPACITOR FXD 33PF x 5 100VDC CER 16299 C327 0160 4801 CAPACITOR FXD 100PF x 596 100VDC CER 16299 C328 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C329 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C330 0160 4801 CAPACITOR FXD 100PF 5 100VDC CER 16299 C331 32 NOT USED C333 34 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C335 NOT USED C336 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C337 0160 4807 CAPACITOR FXD 33P
114. Federal 22522 NA 5 3 MEG ruta c 5 4 5 6 Output Board Replacement Part tente sente tete seitens eese e tese este stet e seien 5 7 b 7 25WPDA Replacement Parts List uu u tr ne n teet een 5 9 5 8 50W 2A Replacement Parts List e cac me e de e Ee ne pte esa ost ss ute e EY YR a 5 18 iv Section INTRODUCTION 1 1 SCOPE This manual contains principles of operation verification and troubleshooting information for the power supply Replaceable parts lists and circuit diagrams are also provided Installation operation programming and calibration procedures as well as detailed specifications are given in a separate Operating Manual Agilent Part No 06626 90001 Wherever applicable the service instructions given in this manual refer to pertinent information provided in the Operating Manual The information in each manual covers model 6625A 6626A 6628A and 6629A The main differences between the models are the number and type of outputs each model contains These differences are specified in each of the manuals The following is a listing of the information contained in this manual with a brief description concerning its scope and purpose Principles of Operation Section II provides block diagram level descriptions of the supply s circuits The GPIB interface digital ci
115. G signal are connected through scaling resistors to summing point 52 for application to U346 CC Error Amplifier as show in figure 2 6 Based on this summing action U346 generates the CL control signal which is applied to the base drive circuit via buffer amplifier U376 and OR gate diode CR348 to control conduction of the series regulators in the power module in the same way as described above for the voltage control circuit The SHUNT signal is also sent back to the secondary interface to indicate the magnitude of the output current The current control circuit receives an input from peak current limit circuit in the current sourcing mode only as shown in figure 2 5 When the peak current limit circuit see paragraph 2 42 is activated it immediately limit the conduction of the series regulators in the power module 2 48 Negative Current Limit Circuit This circuit provides a limit to the amount of current that the supply can sink The circuit may be activates if a current source such as another power supply or energy storage capacitor is connected across the output terminals and its voltage is greater that the programmed output voltage When the output is in negative current limit this circuit generates the control and the CL LOOP signal The CL control signal is applied through diode CR354 to the base drive circuit The CL LOOP signal is sent back to the secondary interface to indicate that the output is in the ne
116. GEN PRP 180V 200MA 9N171 1N645 CR347 NOT USED CR348 1901 0050 DIODE SWITCHING 80V 200MA 9N 171 1N4150 CR349 1901 0518 DIODE SCHOTTKY SM SIG 71785 5082 2800 CR350 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR351 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR352 53 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR354 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR355 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR356 59 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR360 1901 1080 DIODE SCHOTTKY 20V 1A 04713 1N5817 RELAXED 61 62 1901 0731 DIODE PWR RECT 400 1A 71468 1N4004G CR363 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR364 70 NOT USED CR371 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 Table 5 7 25W 0 5 BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No CR380 81 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 D407 0812 0010 RESISTOR FXD 28480 F300 2110 0916 FUSE SUBMINIATURE 7AT 125V 75915 F302 2110 0716 FUSE SUBMINIATURE 5A 125V 75915 F303 2110 0685 FUSE SUBMINIATURE 7A 125V 75915 F304 2110 0713 FUSE SUBMINIATURE 10A 125V 75915 F305 2110 0916 FUSE SUBMINIATURE 7AT 125V 75915 F307 NOT USED F308 09 2110 0303 FUSE 2A 250V TD 16428 L300 9140 0129 INDUCTOR 220UH 5 28480 L301 NOT USED L302 9100 1640 INDUCTOR 160UH 5 99800 Q300 17 NOT USED Q318 1854 0474 TRANSISTOR NPN SI 04713 2N5551 Q319 1854 0477 TRANSISTOR NPN SI 144
117. I 3 2 3 Co ON OFF s E CU FEEDBACK R430 pvp 7 0U T nu 6 81K 0528 2A BD 100PF 2 i E doe SENSE O CR345 R429 V Hem OUT TERM CONTROL 2 3 gt 3 DUT TERM L C423 gt 00 1 SENSE 350 3 gt V SEZ E CU CL CONTROL C389 0V 5 m 392 bp 509 Figure 6 3 Output 1 2 Board Schematic Diagram sheet 4 of 5 6 11 15U A 150 4 57 i CU DAC 0 TO 10V 6 CU PRGM 3 5A Bd 3 336K 4 o 8 2A Bd 9 53K 1000 i i DAC 0 TO 10V 5A 625 s 5 2A Bd 2 253K U381 5V U381 6 6 ANN 554 wo CC PRGM 16 55 UCC 1 U367 150 5 SCLK 19 QCLK SCLR 13 MSB AO l DCO 1 1 1 Y Y 15V SHUNT DROP P O COMP AMP SU SHUNT DROP COMP M C458 0 1 16 500 UCC U368 DC1 u SCLK 151901 15 SCLR OE MSB U I MUX i DO D 0 7 15 501 91 15 555 1 s 5 5 6 Gs sc 1 04 2 5 8 5 5 sc9 Q6 5 SC10 97 2 SC11 sas 5015 HC595 GD LSB 8 x SHUNT I MONITOR 5 4 5 e n SHITCHES READBACK OUT GUARD R605 GUARD SENSE GAIN SELECT SWITCHES BUFFER 1K 2 4 Figure 6 3 Output 1 2 Board Schematic Diagram sheet 5 of 5 6 12 TB1 G o
118. IB board or output board troubleshooting procedures will isolate the problem to the defective component or circuit on the board Before attempting to troubleshoot the supply ensure that the fault is with the supply itself and not with an associated circuit load or power line The verification tests described in Section III enable this to be determined without having to remove the covers from the supply The most important aspect of troubleshooting is the formulation of a logical approach to locating the source of trouble A good understanding of the principles of operation is particularly helpful and it is recommended that Section II of this manual as well as the Operating Manual Agilent Part No 06626 90001 be reviewed before attempting to troubleshoot the unit If a component is found to be defective replace it and reconduct the performance tests given in Section III of this manual When the GPIB board or the EEPROM U221 IC on the GPIB board is replaced each output present in the supply must first be recalibrated as described in Appendix A of the Operating Manual If an Output board is replaced the associated output channel must be recalibrated If a component in the output circuits or readback circuits on an output board is replaced the output must be calibrated before you can reconduct the performance tests Section V in this manual lists all of the replaceable parts for the power supply 4 1 4 2 ELECTROSTATIC PROTECTIO
119. ITOR FXD 2200PF 5 MET POLYE 84411 C437 0160 4554 CAPACITOR FXD 01uF 20 50VDC CER 04222 C438 39 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 440 49 NOT USED C450 52 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C453 54 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 1629 455 56 NOT USED C457 58 0160 4835 CAPACITOR FXD 0 1uF 10 50V 28480 C459 0160 4822 CAPACITOR FXD 100PF 5 28480 C460 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C461 0160 5101 CAPACITOR FXD 14F 10 63VDC MET POLYE 28480 CR300 04 1901 0731 DIODE PWR RECT 400V 1A S0562 CR305 08 NOT USED CR309 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR310 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR311 12 1901 0028 DIODE PWR RECT 400V 750MA 04713 CR313 17 NOT USED CR318 19 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR320 23 NOT USED CR324 1901 0028 DIODE PWR RECT 400 750MA 04713 CR325 1901 0719 DIODE PWR RECT 400V 3A 04713 MR854 CR326 1901 0028 DIODE PWR RECT 400 750MA 04713 CR327 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR328 1901 0028 DIODE PWR RECT 400 750MA 04713 CR329 1901 0050 DIODE SWITCHING 80 200MA 9N171 1N4150 CR330 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR331 35 1901 1098 DIODE SWITCHING 50 200MA 15818 1N4150 CR336 39 NOT USED CR340 1901 0731 DIODE PWR RECT 400V 1A 04713 CR341 1901 0033 DIODE GEN PRP 180V 200MA 9N171 1N645 CR342 44 NOT USED CR345 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR346 1901 0033 DIODE
120. Mfg Mfg No Code Part No R446 0698 4480 RESISTOR 15 8K 1 125W TF 24546 CT4 1 8 TO 1582 F R447 0757 0440 RESISTOR 7 5K 1 125W TF 24546 CT4 1 8 TO 7501 F R448 0757 0469 RESISTOR 150K 1 125W TF 24546 CT4 1 8 TO 1503 f R449 0698 3447 RESISTOR 422 1 125W TF 24546 CT4 1 8 TO 422R F R450 0698 8827 RESISTOR 1M 1 125W TF 19701 R451 0757 0280 RESISTOR 1K 1 125W TF 24546 CT4 1 8 TO 1001 F R452 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R453 0698 4480 RESISTOR 15 8K 1 125W TF 24546 CT4 1 8 TO 1582 F R454 0698 7880 RESISTOR 28 7K 1 125W TF 19701 5033R 1 8 T9 2872 F R455 0698 8827 RESISTOR 1M 1 125W TF 19701 R456 0698 0087 RESISTOR 316 1 25W TF 24546 NA5 1 4 TO 3160 F R457 0811 2553 RESISTOR 7 5 5 2W PW 75042 BWH2 7R5 J R458 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R459 0757 0446 RESISTOR 15K 1 125W TF 24546 CT4 1 8 TO 1502 F R460 0698 8913 RESISTOR 1 5M 1 28480 R461 0683 4735 RESISTOR 47K 5 25W CF 01121 CB4735 R462 0757 0288 RESISTOR 9 09K 1 125W TF 19701 5033R 1 8 TO 9091 F R463 0698 0084 RESISTOR 2 15K 1 125W TF 24546 CT4 1 8 TO 2151 R464 0757 0124 RESISTOR 39 2K 1 125W TF 07716 R465 0698 4484 RESISTOR 19 1K 1 125W TF 24546 R466 70 NOT USED R471 0699 0070 RESISTOR 3 16M 1 125W TF 07716 R472 0698 6363 RESISTOR 40K 1 125W TF 07716 R473 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 3652 F R474 0757 0124 RESISTOR 39 2K 1 125W TF 0716 R475 0683 8235 RESISTOR 82K 5 25W CF 01121 C
121. N This instrument uses components which can be damaged by static charge Most semiconductors can suffer serious performance degradation as a result of static charge even though complete failure may not occur The following precautions should be observed when handling static sensitive devices a Always turn power off before removing or installing printed circuit boards or components b Always store or transport static sensitive devices all semiconductors and thin film devices in conductive material Attach warning labels to the container or bag enclosing the device c Handle static sensitive devices only at static free work stations These work stations should include special conductive work surfaces such as Agilent Part No 9300 0797 grounded through a one megohm resistor Note that metal table tops and highly conductive carbon impregnated plastic surfaces are too conductive they can shunt charges too quickly The work surfaces should have distributed resistance between 106 and 1012 ohms per square d Ground all conductive equipment or devices that may come in contact with static sensitive devices or assemblies e Where direct grounding of objects in the work area is impractical a static neutralizer should be used ionizedair blower directed at work Note that this method is considerably less effective than direct grounding and provides less protection for static sensitive devices f While working with equipment on whi
122. OTING PROCEDURES NOTE If the GPIB board is replaced or it is repaired by replacing EM i the EEPROM chip U230 or 0231 each output in the supply The GPIB troubleshooting procedures in this section apply only to must be recalibrated as described in Appendix A of the earlier through hole board assemblies Surface mount GPIB assemblies are not repairable to the component level If defective Operating Manual Since the EEPROM provides non volatile the entire GPIB assembly must be replaced storage of the supply s Model number and GPIB address you must reassign these values before the calibration Troubleshooting procedures for the GPIB board and Front procedures can be performed on the new or repaired GP Panel are given in the flow chart of Figure 4 6 The IB board The GPIB address is set manually using the front procedures first ensure that the bias voltages for the GPIB panel ADDR key as described in Section III of the Operating board circuits and the Front Panel display are correct The Manual The supply s Model number is set as described in microprocessor clock the RAM and ROM circuits are then the next paragraph checked After these preliminary checks are made signature analysis tests are performed as described in paragraph 4 22 to determine which component is defective 4 21 Setting the Model Number At turn on the supply s model number and letter suffix e g Agilent 6626A are read out of the EEPROM along with 9
123. RESISTOR 301 1 125W TF 100 24546 CT4 1 8 TO 301R F R334 NOT USED 5 12 Table 5 7 25W 0 5A BOARD Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part No R335 36 0757 0473 RESISTOR 221K 1 125W TF 28480 CT4 1 8 TO 2371 F R337 38 0757 0438 RESISTOR 5 1K 1 125W TF 24546 CT4 1 8 TO 5111 F R339 8159 0005 RESISTOR 0 OHMS 28480 R340 0757 0430 RESISTOR 2 21K 1 125W TF 24546 CT4 1 8 TO 2211 F R341 44 NOT USED R345 8159 0005 RESISTOR ZERO OHMS 72982 R346 0698 5579 RESISTOR 5K 5 125W TF 03888 R347 0698 3329 RESISTOR 10K 5 125W TF 03888 PME55 1 8 TO1002 D R348 0698 6533 RESISTOR 12 5K 1 125W TF 19701 R349 0698 7929 RESISTOR 9 09K 1 125W TF 19701 5033R 1 8 TO 9091 B R350 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R351 0698 4493 RESISTOR 34K 1 125W TF 24546 CT4 1 8 TO 3402 F R352 0757 0439 RESISTOR 6 81K 1 125W TF 24546 CT4 1 8 TO 6811 F R353 54 NOT USED R355 0698 3328 RESISTOR 8 25K 5 125W TF 03888 PME55 1 8 TO 8251 D R356 0698 8913 RESISTOR 1 5 1 125W TF 07716 R357 0699 0489 RESISTOR 16 15K 1 1W TF 19701 R358 0757 0469 RESISTOR 150K 1 125W TF 24546 CT4 1 8 TO 1503 F R359 0699 1211 RESISTOR 95K 1 1W TF 19701 R360 0757 0447 RESISTOR 16 2K 1 125W TF 24546 CT4 1 8 TO 1622 F R361 8159 0005 RESISTOR ZERO OHMS 72982 R362 0757 0283 RESISTOR 2K 1 125W TF 24546 CT4 1 8 TO 2001 F R363 64 NOT USED R365 0699 1212 RESISTOR 19K 1
124. RMS Bandwidth 10 MHz Sensitivity 500 zV Oscilloscope Agilent 1740A RMS Voltmeter Rhode and Schwarz Model URE or 3400A Digital Voltmeter DVC Resolution 2V 100 zV 50 V Accuracy 13PPM 2 V DCA Resolution 100 mA 500 mA Accuracy 140PPM 500 mA 1 2 digit Agilent 3458A Current Monitor Resistor Value 0 1 ohm 2 amp Accuracy 005 or better 2 K ohms 2 W 5 GUIDLINE 9330 0 1 Agilent L amp N 4221 B Resistor Figures 3 4 and 3 5 Diodes 2 Figures 3 4 and 3 5 Agilent 0764 0025 100 V 3 A Silicon diode Agilent 1901 0719 or Agilent 1901 1087 Variable Voltage Transformer Adjustable from 13 to 6 of input voltage range 1 VA minimum 64V 0 1A 30V 3A DC Power Supply Figure 3 6 Agilent 6115A Agilent 6296A Electronic Load Voltage Range 50 V minimum Current Range 3 A minimum Power Range 50W minimum Open and Short switches variable at 60 Hz rate Agilent 6060A or Variable Load Resistors and Load Switch 0 to 150 ohms 100 W minimum 500 210W 10 switchable at line freq consists of see Figure 3 6 Relay Capacitor 0 47 100 V Resistor 1 5 ohms 3 W Diodes 2 100 V 1 A Resistor 10 K 3 W Resistor var 25 K 2 W Agilent 0811 1909 Clare HGP 1002 Agilent 0160 5
125. RMWARE 1 1 Section Il PRINCIPLES OF OPERATION 221 INTRODUCTION oeste ee entis 2 1 2 2 OVERALL BLOCK DIAGRAM DESCRIPTION Fig re 2 1 itti redd 2 1 2 3 AC Input Circuits sesi 2 1 2 4 GPIB Board teet eee 2 1 2 5 Front eee 2 1 256 Output Boards tala st rete erat eme 2 1 2 7 GPIB BOARD Figure 2 3 2 3 2 8 GPIB Interface ua a trt 2 3 2 9 System 2 4 2 16 Output Boards Interface 2 4 2 20 Front Panel Interface 2 2 5 2 23 Bias Supply and Start 2 5 224 1 2 7 2 25 Secondary Interface Circuits Figure 2 4 ae esci WAB 2 7 2 37 Power mesh and Control Circuits Fig re2 5 one Masse osa 2 10 Section VERIFICATION 3 1 INTRODUCTION e aid aap eu 3 1 3 2 TEST EQUIPMENT REQUIRED 3 1 3 3 OPERATION VERIFICATION TESTS 3 1 3 4 PERFORMANCE 675 3 1 3 5 Introducti n 3 upas AA 3 1 3 6 Measurement Techniques 3 1 3 10 Constant Voltage CV
126. RTION IN PRRR 4 30 THE OVDRC VOLTRGE SHOULD BE APPROXIMATELY SCALED TO THE PROGRAMMED OVERVOLTAGE VALUE WHERE TO 1 V ON THE DAC ROUGHLY CORRESPONDS 15 8 58 VOLTS PROGRAMMED CHECK OVDRC RMPLIFIER U363 OVDRC U318 SEE FIG 4 10 0319 14 OK YES TURN OFF SUPPLY WITH 0320 DRAIN CASE SHORTED TO COMMON USE AN OHMMETER WITH POSITIVE LEAD ON U338 3 SCR ANODE AND NEGATIVE LEAD ON COMMON TO CHECK SCR LERKRGE USE SIMPSON OHMMETER ON Beat n RANGE OR ima DIODE TEST SCRLE ON RT 25 5 SCR LEAKAGE SHOULD BE CHECK POWER MODULE U338 WITH R498 OR 581 LIFTED AND THE SUPPLY TURNED ON HIGH REMOVE SHORT FROM 0328 LIFT WARNING R488 TURN ON SUPPLY AND SET OUTPUT VOLTAGE AND OVERVOLTAGE TO THE VALUES THAT ORIGINALLY CRUSED PROBLEM SEE WARNING STILL DISPLAYS OVERVOLTAGE TURN OFF SUPPLY LIFT 5 1 TURN ON SUPPLY AND SET OUTPUT OLTRGE AND OVERVOLTAGE TO THE VALUES THAT ORIGINALLY CAUSED THE PROBLEM SEE WARNING TO SHEET 2 4 37 OUTPUT VOLTAGE MAY BE PRESENT EVEN IF THE OUTPUT IS NOT PROGRAMMED UP Figure 4 11 Sheet 1 Overvoltage Troubleshooting Flow Chart CHECK POWER MODULE 7338 SEE FIG 4 13 OUTPUT HELD HIGH TROUBLESHOOTING CHECK COMPONENTS CONNECTED U327 2 CHECK 0375 0351 SENSE PROTECT CIRCUITS CHECK U32 SEE PARA 4 30 OUTPUT VOLTAGE MAY BE SET TOO CLOSE TRIP POINT OR THERE MAY BE AN OVERSHOOT AT POWER ON SEE TROUBLE SYMPTOM
127. Range 2 A 265 P pje amp YP 100 nA I H Display and Readback Accuracy 25W High Range Io 280 Low Range lo 19 5 50W High Range lo 1 35 mA Low Range Io 330 Current Limit Is 25W High Range 52 A to 55 A Low Range same as High Range 50W High Range 1 04 A to 1 10 A Low Range 2 08 A to 2 20 A Display and Readback Accuracy 25W High Range Is 3 mA Low Range same as High Range 50W High Range Is 9 mA Low Range Is 1 4 mA 3 25 CC LOAD EFFECT 25W 5 50W 10 nA 3 26 CC SOURCE EFFECT 25W 5 pA 50W 10 pA 3 27 CC NOISE RMS 100 2 For model Agilent 6629A outputs 1 and 2 are 50 watt for Agilent 6626A they are 25 watt 3 16 Section IV TROUBLESHOOTING Most of the maintenance procedures given in this section are performed with power applied and protective covers removed Such maintenance should be performed only by service trained personnel who are aware of the hazards involved for example fire and electrical shock 4 1 INTRODUCTION This section provides troubleshooting and repair information for the power supply The troubleshooting technique is to first isolate the problem to an assembly and then follow the troubleshooting procedure provided for the faulty assembly The assembly GP
128. S TABLE 4 19 Figure 4 11 Sheet 2 Overvoltage Troubleshooting Flow Chart 4 38 FUSIBLE RESISTOR R487 OPEN REPLACE AND ALSO CHECK 54866 AND R420 WITH SUPPLY OFF MAKE SURE THERE IS NOT A SHORT ACROSS THE OUTPUT THE OUTPUT SHOULD LOOK LIKE A DIODE CATHODE ON V IN PARALLEL WITH ABOUT 2K OHM TURN ON SUPPLY IF THE BIAS REFERENCE AND RAIL VOLTAGES BEEN CHECKED DO SO NOW AS DESCRIBED IN FIG 4 8 CHECK CVDRC RPLIFIER U313 R381 SEE FIG 4 18 CHECK CCDRC RPPLIFIER U314 U361 R381 SEE FIG 4 18 CHECK U364 367 CHECK THAT THE ON OFF SIGNAL AT U32 eS IS 2 4V NO NO SEE FIG 4 8 SHEET YES YES CHECK U327 CR331 CR333 AND 0348 SEE FIG 4 16 Figure 4 12 Sheet 1 Output Held Low Troubleshooting Flow Chart 4 39 FROM SHEET 1 CHECK THAT THE VOLTRGE ACROSS EACH RESISTOR R379 R38 AND AND R38 IS 1 2V TO SHEET 3 CHECK THE CURRENT THROUGH R428 BY MEASURING THE VOLTAGE ACROSS IT THE VOLTAGE SHOULD BE 0 35 VOLTAGE ACROSS R428 gt 25 SHEET 3 CR348 245 CONDUCT ING CHECK C323 73428 VOLTAGE CHECK FOR LEAKY CR354 ACROSS 8451 CHECK 325 CHECK FOR 50 6 VOLTA av 1 gt Smv CHECK 097 SA LEAKY 5355 co CR35 E CHECK U346 INPUTS 1 mv CLAMP CONDUCT ING CHECK 0335 03750 CHECK R408 CHECK U34 CHECK FOR LEAKY CR353 VOU TAE w gt CHECK U352 U3 3 0374
129. SERVICE MANUAL MULTIPLE OUTPUT LINEAR SYSTEM DC POWER SUPPLY AGILENT MODELS 6625A 6626A 6628A and 6629A Agilent Part No 06626 90003 Agilent Model 6625A Serial 3738A 01389 through 01408 US37380101 and up Agilent Model 6626A Serial 3737A 02259 through 02328 US37370101 and up Agilent Model 6628A Serial 3738A 00683 through 00727 US37380101 and up Agilent Model 6629A Serial 3738A 00968 through 00997 US37380101 and up For instruments with higher Serial Numbers a change page may be included DR Agilent Technologies Microfiche Part No 06626 90004 Printed in Malaysia September 2001 CERTIFICATION Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Bureau of Standards to the extent allowed by the Bureau s calibration facility and to the calibration facilities of other International Standards Organization members WARRANTY This Agilent Technologies hardware product is warranted against defects in material and workmanship for a period of three years from date of delivery Agilent software and firmware products which are designated by Agilent for use with a hardware product and when properly installed on that hardware product are warranted not to fail to execute their programming instructions due to defects in material and workmanship for a
130. SING FN GPIB CONTROLLER CHECK AC INPUTS TO THE OUTPUT PROGRAM ANY OUTPUT CHANNEL S BOARDS SEE FIG 6 1 VOLTAGE AND READBACK THE NO E CHECK TRANSFORMER AND CABLES YES OUTPUT VOLTAGE TROUBLESHOOT THE GPIB BOARD SEE PARA 4 18 CHECK GPIB CABLE IF CABLE IS OK TROUBLESHOOT THE GPIB BOARD SEE PARA 4 18 TEST REFER TO TABLE 4 13 Figure 4 5 Sheet 1 Initial Troubleshooting and Board Isolation 4 13 CHECK THAT AC INPUT GPIB BORRD IS 12VAC SEE FIG 6 1 CHECK POWER TRANSFORMER AND AC CRELE TO GPIB BOARD TROUBLESHOOT GPIB BOARD SEE PARA 4 18 TO DETERMINE IF GPIB BOFRD OR DISPLAY IS DEFECTIVE IF THE ERR ANNUNCIATOR IS ON REFER TO TABLE 4 5 IF THE CV AND CC CV AND UNR OR CC AND UNR ANNUNCIATORS ARE ON FOR A SEE POWER ON SELF TEST ERROR MESSRGES TRBLE 4 4 NOTE THRT IF THERE FRE DRC OR FUSE ERROR CHECK CABLE IF CABLE OK TROUBLESHOOT THE GPIB BOARD TROUBLESHOOT THE OUTPUT BOARD SEE PRRA 4 18 SEE PARA 4 25 Figure 4 5 Sheet 2 Initial Troubleshooting and Board Isolation 4 14 SET UP THE GPIB BOARD FOR TROUBLESHOOTING SEE PARA 4 19 AND TURN ON THE SUPPLY CHECK THE SV BIRS VOLTAGE AT P221 2 CHECK CR281 CR224 U218 F201 IF THE DISPLAY DOES NOT WORK CHECK THAT THE FRONT PANEL DISPLAY OPERATING VOLTAGES AT R213 ARE AS FOLLOWS R219 9 3 3 R219 2 2 2V R219 15 1 1 CHECK RT2 1 R219 R214 C213 CHECK THAT 201 13 AND
131. TN is false only devices that are addressed will actively send or receive data All unaddressed devices will ignore the data lines when ATN is false 2 9 System Micro Computer The system micro computer decodes and executes all instructions and controls all data transfers It consists of a microprocessor an address decoder RAM and ROM memories data buffers latches and a real time clock as shown in Figure 2 3 2 10 Microprocessor and Clock Circuits These circuits contain a high performance 8 bit microprocessor U201 and associated clock circuits The microprocessor operates on a 1 MHz cycle which it derives from a 4 MHz ceramic resonator oscillator Y201 The 1 MHz Q signal is generated by the microprocessor for use by other circuit A 4 millisecond approximately clock signal applied to the microprocessor interrupt input enables the microprocessor to keep track of real time This allows the microprocessor to form necessary tasks on a regular basis The real time clock signal is also used to keep track of the time that has elapsed since the output was last changed This enables microprocessor to determine if a CV CC mode change occurred before the selected time delay see Reprogramming Delay discussion in Section V of the Operating Manual The microprocessor inhibits the OCP function until the delay is over The microprocessor also uses the 4 millisecond clock to determine when to refresh the front panel display and to perform o
132. TO 6811 F R217 0757 0411 FILM 332 1 1 8W 24546 CT4 1 8 TO 322R R218 0757 0438 FILM 5 11K 1 1 8W 24546 CT4 1 8 TO 6811 R219 1810 0560 RES NETWORK 16 DIP 5 6Kx8 28480 R220 22 0757 0442 FXD FILM 10K 1 96 1 8W 24546 CT4 1 8 TO 1002 F R223 30 0757 0438 FXD FILM 5 11K 1 96 1 8W 24546 CT4 1 8 TO 6811 F R231 32 0757 0280 FXD FILM 1K 1 96 1 8W 24546 CT4 1 8 TO 1001 F R233 0757 0438 FXD FILM 5 11K 1 96 1 8W 24546 CT4 1 8 TO 6811 F R234 0698 4440 FXD FILM 3 4K196 1 8W 24546 CT4 1 8 TO 3401 F R235 41 NOT USED R242 8159 0005 RESISTOR ZERO OHMS R243 8159 0005 RESISTOR ZERO OHMS R244 407 NOT USED R408 0811 3821 RESISTOR RT201 0837 0412 THERMISTOR ROD 28480 U201 1820 2490 IC MPU 04713 MC6809 U202 1820 2549 IC 8291A TALKER LISTENER 28480 U203 1LH4 00010 GPIB TRANSCEIVER 28480 U204 1820 1730 IC SN74LS273N U205 NOT USED U206 5080 2093 PRGMD EPROM STANDARD 28480 U207 1818 1845 IC NMOS 16K STAT RAM 34335 AM9128 10PC U208 1820 1216 IC DCDR TTL LS 3 TO 8 LINE 01395 SN74LS138N 5 7 Table 5 6 GPIB Through hole Replacement Parts List Continued Design Agilent Part Description Mfg Mfg No Code Part U209 1820 0935 IC COUNTER CMOS BIN 04713 MC14020BCP U210 1820 3848 IC FF CMOS D TYPE 04713 MM74HCT374N 0211 1820 1427 DCDR TTL LS 2 TO 4 LINE 01295 SN74LS156N U212 1820 2024 IC LINE DRIVER TTL LS OCTAL 01295 SN74LS244N U213 1820 1997 IC FF TTLLS D TYPE 01295 SN74LS374PC 214 1820 2
133. U323 along with the microcomputer U312 form an analog to digital converter ADC which monitors the output board signals sent to the analog multiplexer The readback DAC U321 and amplifier U362 convert the digital input signal from the microcomputer to an analog signal in the range of 0 to 10 volts The DAC internally formulates the 14 bit DAC data from the 8 bit DB0 DB7 data bus same as the CV DAC described above The output of the DAC and the output of the analog multiplexer are applied to the signal comarator U324 The readback DAC under the control of the microcomputer successively approximates the value of the multiplexer s output to a 14 bit resolution Starting from the most significant bit each bit is successively compare to the multiplexer s output and is kept or discarded depending on whether its value is less than kept or greater than discarded the multiplexer s output Each comparison successive approximation is evaluated by the microprocessor via its INT input The microcomputer maintains a running total of the approximations sum of the kept bits which when complete represents the value of the analog multiplexer s output 2 33 CV and CC Programming Range Switching U367 U364 and resistor pack U381 determine the attenuation factor for the CV and CC signals Programming range latchU367 receives information via the data bus DOO and DO1 which determines if the power supply will operate the low or h
134. U348 1858 0083 TRANSISTOR ARRAY 56289 TPQ6002 U349 NOT USED U350 1826 0493 IC OP AMP LOW BIAS H IMPD 27014 LM308AN U351 1826 0138 IC COMPARATOR GP QUAD 27014 LM339N U352 1826 1896 10858 LT1001CN8 U353 NOT USED U354 1826 0468 IC V RGLTR OV V SEN 04713 MC34062P1 U355 59 NOT USED U360 62 1826 1895 10858 LT1001ACN8 U363 1826 1068 IC D A 8 BIT 27014 DAC0832LCN U364 66 1826 2191 17856 DGP201ADJ U367 68 1820 3344 IC SHF RGTR CMOS 74HC ASYNCHRO SERIAL IN 04713 MC74HC595N U369 1820 2102 IC LCH TTL LS D TYPE OCTL 01295 SN74LS373N U370 1820 1201 IC GATE TTL LS AND QUAD 2 INP 01295 SN74LS08N U371 72 1826 1895 10858 LT1001ACN8 U373 74 1826 1896 10858 LT1001CN8 U375 1826 1302 IC OP AMP LP QUAD 27014 LF444ACN U376 77 1826 0493 IC OP AMP LOW BIAS H IMPD 27014 LM308AN 0378 1826 1895 10858 LT1001ACN8 U379 1810 1266 RESISTOR NETWORK 28480 U380 1810 1267 RESISTOR NETWORK 28480 U381 1810 1263 RESISTOR NETWORK 28480 U382 1810 1262 RESISTOR NETWORK 28480 VR300 04 NOT USED VR305 1902 1377 DIODE ZNR 6 19V 2 04713 VR306 1902 0182 DIODE ZNR 20 5V 5 15818 VR307 14 NOT USED VR315 1902 0057 DIODE ZNR 6 49V 5 15818 VR316 1902 0244 DIODE ZNR 30V 5 07263 VR317 89 NOT USED VR390 1902 3323 DIODE ZNR 42 2V 5 15818 VR391 99 NOT USED VR400 01 1902 0783 DIODE ZNR 16V 5 04713 VR402 1902 0064 DIODE ZNR 7 5V 5 04713 Y300 0410 1627 RESONATOR CERAMIC 4 0MHZ 28480 Section CIRCUIT DIAGRAMS 6 1 INTRODUCTION This section contains functional sche
135. USED U350 1826 0493 IC OP AMP LOW BIAS H IMPD 27014 LM308AN U351 1826 0138 IC COMPARATOR GP QUAD 27014 LM339N U352 1826 1896 10858 LT1001CN8 U353 NOT USED U354 1826 0468 IC V RGLTR OV V SEN 04713 MC34062P1 U355 59 NOT USED U360 62 1826 1895 10858 LT1001ACN8 U363 1826 1068 IC D A 8 BIT 27014 DAC0832LCN U364 66 1826 2191 17856 DGP201ADJ U367 68 1820 3344 IC SHF RGTR CMOS 74HC ASYNCHRO SERIAL IN 04713 MC74HC595H 0369 1820 2102 IC LCH TTLLS D TYPE OCTL 01295 SN74LS373N U370 1820 1201 IC GATE TTL LS AND QUAD 2 INP 01295 SN74LS08N 0371 72 1826 1895 10858 LT1001ACN8 U373 74 1826 1896 10858 LT1001CN8 U375 1826 1302 IC OP AMP LP QUAD 27014 LF444ACN 0376 77 1826 0493 OP LOW BIAS H IMPD 27014 LM308AN U378 1826 1895 10858 LT1001ACN8 U379 1810 1266 RESISTOR NETWORK 28480 U380 1810 1267 RESISTOR NETWORK 28480 U381 1810 1263 RESISTOR NETWORK 28480 U382 1810 1262 RESISTOR NETWORK 28480 VR300 4 NOT USED VR305 1902 1377 DIODE ZNR 6 19V 2 04713 VR306 1902 0182 DIODE ZNR 20 5V 5 15818 VR307 14 NOT USED VR315 1902 0057 DIODE ZNR 6 49V 5 15818 VR316 1902 0244 DIODE ZNR 30V 5 07263 VR317 89 NOT USED VR390 1902 3323 DIODE ZNR 42 2V 5 15818 VR391 99 NOT USED VR400 1 1902 0783 DIODE ZNR 16V 5 04713 VR402 1902 0064 DIODE ZNR 7 5V 5 04713 Y300 0410 1627 RESONATOR CERAMIC 4 0MHZ 28480 Table 5 8 50W 2A BOARD Replacement Parts List Design Agilent Part Description Mfg Mfg No Code Part No C300 0160 4833 CAPACITOR
136. V DVM 18 mV q Run the program listed in step e Record the value displayed bye the controller This value should be within the DVM reading 18 mV r Repeatsteps a through q for each output present in your supply 3 13 CV Load Effect This test measures the change in output voltage resulting from a change in output current from full to no load a Turn off the supply and connect the output to be tested as shown in Figure 3 3 with the DVM connected between the S and 5 terminals the Load switch closed and the Short switch opened CC TESTS Figure 3 3 Basic Test Setup b Turn on the supply and select the output to be tested OUTPUT SELECT key on front panel c Program the current of the selected channel to the values below by sending the following strings 25W ISET ch 0 515 VSET ch 50 50W ISET ch 1 03 VSET ch 50 d Adjust the load for 0 5 Amp 25W or 1 Amp 50W as indicated on the front panel display The CV annunciator on the front panel must be on If it is not adjust the load down slightly e Record the output voltage reading on the DVM connected to S and S f Open the Load switch and again record the DVM voltage reading The difference between the DVM readings in steps e and f is the load effect voltage and should not exceed 0 5 mV Repeat steps through f for each output in your supply 3 14 CV Source Effect This test measures the change in output voltage that resul
137. XD 047uF 20 50VDC CER 16299 C429 0160 5098 CAPACITOR FXD 22uF 10 50VDC CER 16299 CAC05X7R224J050A C430 31 NOT USED C432 0160 4822 CAPACITOR FXD 1000PF 5 100VDC CER 16299 C433 0160 4791 CAPACITOR FXD 10PF 5 100VDC CER 16299 C434 NOT USED C435 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C436 0160 6999 CAPACITOR FXD 2200PF 5 MET POLYE 84411 C437 39 0160 4835 CAPACITOR FXD 1yF 10 50VDC CER 16299 C440 49 NOT USED C450 52 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C453 54 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C455 56 NOT USED C457 58 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C459 0160 4822 CAPACITOR FXD 1000PF 5 100VDC CER 16299 C460 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C461 0160 5101 CAPACITOR FXD 1uF 10 63VDC MET POLYE 28480 CR300 04 1901 0731 DIODE PWR RECT 400V 1A 04713 IN4004G CR305 08 NOT USED CR309 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR310 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR311 12 1901 0028 DIODE PWR RECT 400V 750MA 04713 CR313 17 NOT USED CR318 19 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR320 23 NOT USED CR324 1901 0028 DIODE PWR RECT 400V 750MA 04713 CR325 1901 0719 DIODE PWR RECT 400V 3A 300NS 04713 MR854 CR326 1901 0028 DIODE PWR RECT 400V 750MA 04713 CR327 1901 0731 DIODE PWR RECT 400V 1A 71468 1N4004G CR328 1901 0028 DIODE PWR RECT 400V 750MA 04713 CR329 1901 0050 DIODE SWITCHING 80V 200MA 9N171 1N4150 CR330 1901 0033 DIODE GEN PRP 180V
138. Y IS EXPRESSED OR IMPLIED Agilent SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER S SOLE AND EXCLUSIVE REMEDIES Agilent SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY ASSISTANCE The above statements apply only to the standard product warranty Warranty options extended support contracts product maintenance agreements and customer assistance agreements are also available Contact your nearest Agilent Technologies Sales and Service office for further information on Agilent s full line of Support Programs NI SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation service and repair of this instrument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Agilent Technologies assumes no liability for the customers failure to comply with these requirements BEFORE APPLYING POWER Verify that the product is set to match the available line voltage and the correct fuse is installed GROUND THE INSTRUMENT This product is a Safety Class 1 instrument provided with a protective earth terminal To minimize shock hazard the instrument chassis and
139. YAS 85 POST 2110 0936 g o a E dh S lt 2 55 R230 85 RZL 598 zo T me NL1901 1375 gt ME 55 EF 27 541K 28 L201 U220 NS TA Ysxe 2 is A HS218 R262 5 U284 wl e 4 B CSB u220 e 0699 1385 SHDN r3 R217 88 8 8 1 Q201 og 2 2 4576 220UH ee 1 AAA ee R231 224 5 lt aos n 2 ANR SZ 5 5 1 1205 0886 0218 0699 1818 18266652 91402387 lt Q e 348 RAMA 88 ES B xz 565 5 4 LM340AK 5 5 e VIN FB g lt SLE 4 0699 1428 1826 1572 un RE ow 8 298 9 2 IN Our e GND Sex arse 0699 1318 8 al 25 gt 580188 a gt t jes gt 8 R221 NL1826 0536 316 82 8 23 Log R232 na lt AAA O T gt e wo o G 8 5 A Log 189 poc c AV 2 Alia VVV o5 R So Ou GND1 GND2 gt RES 558 A OS 5 WV rors 10K 587 ses 8 5 5 Se 2 5 8 5098 5 8 19 gt Nre ANTXO a gt 8 2 8 B AY 8 3 4 S Lc QL me 8 L OTZ4 9 C SZETT ES 1K C Po y ee 0699 1391 ave ZA lt s REG Ry wa 28 Ame TN o 22589 RFS as 58 lt 6 0699 1318 EX S 8 SOT Sg 8 s 81 x8 515 Q lt 8 eO Age 8 r Q225 s 55 158 8 NTa g 8 a lt R25 35 R204 58 R28 ool o C223 FINE T AA eww 2 196K 511K JEZ 0 1 10 069
140. a the and OV terminals As shown in Figure 2 9 the main input to the overvoltage protection circuits in the OV DRIVE signal which is received from the overvoltage detector P O U327 see paragraph 2 32 The OV DRIVE signal goes high to activate the OV GATE signal which is sent via diode CR357 to fire the SCR in the power module The conditions which activate OV DRIVE are described in the following paragraphs VOLTAGE 2 8 0 6 0 5 0 4 0 3 0 2 0 1 0 01 IOUT SINK AMPS TYPICAL DOWNPROGRAMMING CHARACTERISTICS BELOW 4 VOLTS 25W 5A If the output voltage from V R359 exceeds the programmed overvoltage setting derived from OV REF through R357 the overvoltage comparator signal OV COMP goes positive and activates the OV DRIVE and will fire the SCR provided that the POV DISALE signal is low The CURRENT COMP signal is included in the comparison to compensate for the voltage drop across the current monitoring resistor and permit an accurate comparison The POV DISABLE signal is high only during power on and for a brief time during an overvoltage reset Note that the OV DRIVE signal is also sent to the OV terminals via diode CR356 and transformer T301 to either notify a remote circuit that the overvoltage circuit was tripped or alternatively to fire other output boards up to eight by paralleling the external OV lines The OV TRIP signal can activate the OV DRIVE and shut down the supply regardless of the
141. ams and the schematics Logic Symbology Appendix A gives a brief description of the logic symbols used on the functional schematics Fault Indicator FLT and Remote Inhibit INH A fault indicator and remote inhibit circuit which provide additional shutdown protection should either the GPIB and or controller fail are available optionally See a separate document entitled Appendix E Option 750 Operating Instructions for the Multiple Output Linear System DC Power Supply Agilent Models 662xA Agilent P N 5957 6372 1 2 SAFETY CONSIDERATIONS This product is a Safety Class 1 instrument which means that it is provided with a protective earth terminal The instrument and this manual should be reviewed for safety markings and instructions before operation Refer to the Safety Summary page at the beginning of this manual for a summary of general safety information Safety information for specific procedures is located at appropriate places in the manual 1 3 INSTRUMENT AND MANUAL IDENTIFICATION Agilent Techonologies instruments are identified by a two part Serial number i e 2601A 00101 The first part of the serial number the prefix is a number letter combination that denotes either the date of manufacture or the date of a significant design change It also indicates the country of manufacture The first two digits indicate the year 25 1985 26 1986 etc the second two digits indicate the week and A designates the
142. are no errors You sent a character that the supply did not recognize The format of your number string is incorrect Check syntax see Section V in the Operating Manual You sent a command that the supply did not understand Check command sum mary see Appendix C in the Operating Manual You sent a command with improper syntax Check the syntax of your command see Section V in the Operating Manual An out of range number was sent Send a new number within the acceptable range If the error occurs again the output may require calibration See Appen dix A in the Operating Manual The computer addressed the supply to talk but it did not first request data Send query first then address supply to talk Quoted string in the DSP command exceeds the display length of 12 characters May occur if too many characters are sent Error code 4 or 5 is more likely to oc cur for the condition The EEPROM U230 or U231 on the GPIB board is not responding correctly to programming commands Try recalibrating see Appendix A in Operating Manual If calibration doesn t work troubleshoot the GPIB board see paragraph 4 18 An error has occurred on an output The problem may be on the GPIB or the output board This error only occurs if the SKIP SELF TEST jumper is installed and the channel with the hardware error is selected to be displayed Error codes 11 through 14 refer to a specific output where an error has occurred If all output chann
143. at nominal line voltage E 4 18 Typical Power Module U338 Voltage Levels Output Voltage Board Referenced to Reference pin Na Note 3 2 Emitter 3 High Rail Common 4 Medium Rail Common 5 Bypass V 6 Low Rail Common 7 Thermistor Note 4 Common 8 Collector Output Common 9 O V Bias pin 3 Output Sense Common OV Gate Common Common Common Drive V Drive pin 13 Notes 1 Conditions a Output voltage set to maximum programmable value 20V or 50V b No load on output c Nominal line voltage 2 Voltages are referenced to V or Common or another power module pin as indicated in the table 3 The Thermistor output pin 1 level of 4 5 V was measured at a temperature of 25 C Voltage decreases with a rise in temperature OVERTEMP occurs at approximately 2 5 V 4 34 Miscellaneous Trouble and Remedies Symptoms Table 4 18 lists various trouble symptoms along with suggested remedies Most of the trouble symptoms are concerned with an output not meeting a particular specification Verification tests for all specifications are given in Section III of this manual Table 4 19 Miscellaneous Trouble Symptoms Trouble Symptom Spikes on output Ripple on output Poor transient response or oscillations on the output CV load effect CC load effect Line regulation Readback Error Overshoot or overvoltage at turn on output may apparently work pr
144. ation D2 A logic 0 indicates Remote Inhibit is true OPTION 750 A logic 1 indicates OPTION 750 is installed in power supply All buffer outputs are held in the high impedance state disconnecting it from the data bus when CS4 is not decoded 2 23 Bias Supply and Start Up Circuit The bias supply U218 provides 5 V bias power to operate the circuits on the GPIB board The start up circuit U220 U222 generates the OPTO PON signal delayed 5 V which is used to power the optical isolators on the output boards The OPTO PON signal is initially held low for approximately 100 ms to prevent the erroneous transfer of data at power on The start up circuit also generates PCLR power clear and EEPON EEPROM power on signals when power is turned on The PCLR signal is held low at power on to initialize the talker listener and microprocessor chips The EEPON signal is held low at power onto disable the EEPROM clock Thus the start up circuit delays turning on the microprocessor and optoisolators until the bias voltages have stabilized If the line voltage drops after the unit has been turned on the start up circuit will again generate the low level signals to disable the interface and remove power from the supply s outputs 572004 TH NI 1826382 LON 359 CNY 50508 INAO 5 110 53017051 019 OL AS 8 2 914 BS b 1 SOMOB KAOL 505908 LL 5030
145. ature 5 P201 1 3U9F U216 2 U216 4 SYSTEM U216 6 MICROCOMPUTER U216 8 DATA BUFFERS U216 11 U216 U216 13 U216 15 U216 17 U210 3 U210 2 U210 4 U210 5 FRONT PANEL U210 7 U210 6 INTERFACE U210 8 U210 9 DATA LATCHES U210 13 U210 12 U210 U210 14 U210 15 U210 17 U210 16 U210 18 U210 19 Note The output of U210 to keyboard is not tested during S A 4 23 Table 4 12 GPIB Board S A Test No 7 Description This test checks Data Buffers U214 which send data back to the System Microcomputer from the Front Panel The test is made with no front panel keys despressed Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer Edge P201 PIN Input Setting Connection START 11 STOP 12 CLOCK 18 GND 4 Measurements Use the data probe to take signatures for each circuit at the input and output pins listed below Do not press any front panel keys Circuit Input Signature Output Signature 5 P201 1 3U9F U214 2 214 18 3U9F 0214 4 0214 16 3U9F FRONT PANEL U214 6 U214 14 3U9F INTERFACE U214 8 U214 12 0000 DATA BUFFERS U214 11 U214 12 0000 0214 0214 13 214 00 08 0214 15 0214 17 Note The output of 17210 to keyboard is not tested during S A Errors in input signature to 9214 may be caused by U210 4 24 Table 4 13 GPIB Board S A Test No 8 Description This test checks the operation of each key on the fron
146. bottom horizontal line Look for a smooth exponential waveform with no kinks or aberrations Perform a time constant check by insuring that the output voltage falls to about 3776 18 5 V in less than 750 uS Refer to the Channel A waveform shown in Figure 3 8 Now observe Channel B on the oscilloscope while maintaining the trigger on Channel A as in step f Note that the diode clamp used in the test setup of Figure 3 7 prevents gross overload of Channel B which is set at 50 mV div allowing examination of the tail of the exponential waveform The output voltage should be within 50 mV of its final settling value on the bottom horizontal line in less than 6 msec Refer to the Channel B waveform shown in Figure 3 8 Repeat steps a through h for each output in your supply CHANNEL B S mv Div 2 PROGRAMMING RESPONSE TIME lt 6mS Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel First program the selected output s voltage to 50 volts by sending the following string VSET lt ch 50 Set the vertical sensitivity switch of Channel A on the oscilloscope to 10 V div With the oscilloscope s input switch in GND position adjust the trace to the bottom horizontal line Then set the input switch to the dc coupled position Set the vertical sensitivity switch of channel B on the oscilloscope to 50 mV div and the input switch to the GND position Adjust the C
147. cabinet must be connected to an electrical ground The instrument must be connected to the ac power supply mains through a three conductor power cable with the third wire firmly connected to an electrical ground safety ground at the power outlet For instruments designed to be hard wired to the ac power lines supply mains connect the protective earth terminal to a protective conductor before any other connection is made Any interruption of the protective grounding conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury If the instrument is to be energized via an external autotransformer for voltage reduction be certain that the autotransformer common terminal is connected to the neutral earthed pole of the ac power lines supply mains FUSES Only fuses with the required rated current voltage and specified type normal blow time delay etc should be used Do not use repaired fuses or short circuited fuseholders To do so could cause a shock or fire hazard DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gases or fumes KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers Component replacement and internal adjustments must be made by qualified service personnel Do not replace components with power cable connected Under certain conditions dangerous voltages may exist even
148. ch no point exceeds 500 volts use a conductive wrist strap in contact with skin The wrist strap should be connected to ground through a one megohm resistor A wrist strap with insulated cord and built in resistor is recommended such as 3M Co No 1066 Agilent Part No 9300 0969 small wrist size and 9300 0970 large Do not wear conductive wrist strap when working with potentials in excess of 500 volts the one megohm resistor will provide insufficient current limiting for personal safety g grounding device being repaired test equipment soldering iron work surface wrist strap etc should be done to the same point h Do not wear synthetic e g nylon clothing Keep clothing of any kind from coming within 12 inches of static sensitive devices i Low impedance test equipment signal generators logic pulsers etc should be connected to static sensitive inputs only while the components are powered j Use a mildly activated rosin core solder such as Alpha Metal Reliacor No 1 Agilent Part No 8090 0098 for repair The flux residue of this type of solder can be left on the printed circuit board Generally it is safer not to clean the printed circuit board after repair Do not use Freon or other types of spray cleaners If necessary the printed circuit board can be brushed using a natural bristle brush only Do not use nylon bristle or other synthetic bristle brushes Do not use highvelocity air blowers u
149. d 14 OUTPUT SELECT 9 and 14 OUTPUT SELECT 10 and 14 voLT 1 11 and 14 RANGE V J 12 and 14 6 2 and 7 5 8 and 7 4 6 and 7 9 and 7 10 and 7 11 and 7 12 and 7 13 and 7 2 and 5 8 and 5 6 and 5 9 and 5 10 and 5 11 and 5 12 and 5 13 and 5 2 and 3 8 and 3 0 6 and 3 OUTPUT ON OFF 9 and 3 CURR 10 and 3 RESET 11 and 3 RCL 12 and 3 STO 13 and 3 4 27 4 25 OUTPUT BOARD TROUBLESHOOTING PROCEDURES Overall troubleshooting procedures for an output board are given in Figure 4 8 This flow chart is used when a fault has already been isolated to a particular output board using the board isolation procedures see paragraph 4 14 The procedures of Figure 4 8 will isolate the problem to a component s on the defective output board or will refer you to other troubleshooting charts Figures 4 10 to 4 14 to continue troubleshooting Figure 4 9 illustrates waveforms on the output card to aid you in troubleshooting Figure 4 10 provides troubleshooting procedures when a problem has been isolated to one to the DAC amplifier circuits on the defective output board Figures 4 11 through 4 14 provide troubleshooting procedures for various trouble symptoms which may be encountered In addition to the troubleshooting flow charts described above subsequent paragraph in this section contain special troubleshooting information for some of the complex circuits on an output board Troubleshooting information is included for Analog Mu
150. ded models are listed 4 13 FUSE REPLACEMENT Table 4 2 gives the rating of the fuses in the supplies The clip mounted ac line fuse is located in the line module on the rear of the supply The line module also contains a voltage selection card which must be set to the associated ac input 100 120 220 or 240 VAC Section II in the Operating Manual Agilent 5957 6332 explains how to change the line voltage setting The GPIB board has one fuse F201 as shown in Figure 4 2 The output board fuse locations are shown in Figures 4 3 and 4 4 The fuses are shown schematically in Figures 6 1 through 6 3 in the rear of this manual Recommended Model Agilent34588A Agilent34588A Agilent 1740A Table 4 2 Fuses Location Ref Desig Description Rating Agilent Part No AC Line Module Figure 6 1 Main fuse ac line Clip mounted in line module on rear of unit For 100 120 V 8 A 250 V Normal Blow or For 220 240 V 4A 250 V Normal Blow GPIB Board Figure 6 2 F201 Bias supply fuse Soldered to board 4 A 125 V 2110 0712 Output Board Fig 6 3 Sheet 2 2110 0342 2110 0055 F300 F301 Secondary ac input fuses 7 A 125 V 2110 0685 F305 F306 F302 Output bleed circuit and downprogrammer circuit fuse 0 5 A 125 V 2110 0716 F303 Output return fuse 7 125 2110 0685 F304 Secondary ac input fuses 10 A 125 V 2110 0713
151. e 0 mA 50W High Range 0 mA Low Range 0 mA 3 12 100 KA 15 nA 500 185 pA I Display and Readback Accuracy 25W High Range Io 130 nA Low Range Io 15 KA 50W High Range Io 550 Low Range Io 250 CC PROGRAMMING Q Full Scale Output Accuracy Io 25W High Range 500 mA 300 nA ar Low Range 15 mA 21 4A Jr 50W High Range 2 A 1 3 mA OR MESI Low Range 2 A 265 4A ERG Display and Readback Accuracy 25W High Range Io Low Range Io E 50W High Range Io DE Low Range lo Current Limit Is 25W High Range 52 A to 55 A Low Range same as High Range talt 50W High Range 0 7 A to 1 30 Bange Z 09A t0 2 20 m ana ent Display and Readback Accuracy 25W High Range Is 3 mA Low Range same as High Range Soa 2 Low Range Is 1 4 mA 50W High Range Is 9 mA CC LOAD EFFECT 25W 5 nA 50W 10 3 26 CC SOURCE EFFECT 25W 5 mA 10 4A 3 27 CC NOISE RMS 100 A For model Agilent 6628A output 1 is 50 watt for Agilent 6625A output 1 is 25 watt 3 15 Table 3 4 Performance Test Record for Agilent 6626A 6629 Serial No Temperat
152. e setting the 120 VAC cooling fan either runs directly from the line or from the appropriate transformer tap The power transformer provides the main ac inputs to the output boards and also provides the ac inputs for the bias voltage supplies located on the GPIB board and each output board Ac power distribution is shown in detail in Figure 6 1 in the rear of this manual 2 4 GPIB Board The GPIB board contains the GPIB interface system microcomputer output boards interface and front panel interface These circuits provide the interface between the user and the multiple outputs of the power supply Each output board is actually an output channel that can be individually selected and controlled over the GPIB or from the supply s front panel The GPIB board inte prets commands from the GPIB or from the front panel to control the selected output The GPIB board also processes measurement and status data received from the output boards This data may be read back to the controller over the GPIB and or displayed on the supply s front panel Also each output board can be individually calibrated over the GPIB using calibration commands See Appendix A in Operating Manual Correction factors are calculated during calibration and stored in non volatile memory on the GPIB board The GPIB board is described in greater detail in paragraph 2 7 2 5 Front Panel Most of the remote operations that can be performed via the GPIB can also be perform
153. e supply passes the power on self test The normal power on self test indications are described in Section III of the Operating Manual If the supply passes self test the procedures check to see if each output channel can be programmed from the front panel and from the GPIB controller and if calibration is required If the supply passes all of these tests you are referenced to a table at the end of this section that lists various troubles and remedies not covered by the flow chart If the supply does not pass self test as indicated by a blank display the flow chart isolates the problem to either an ac input problem a defective GPIB board or a defective display If the supply does not pass self test as indicated by a power on self test or ERR message the flow chart isolates the problem to the GPIB board one of the output boards or to cabling 4 15 Power On Self Test The power on self test sequence performs tests on the GPIB board as well as on each output board in the supply Table 4 3 lists the tests the boards tested and the error message that appears on the display if a particular test fails Note that two of the output board test the RAM and ROM tests are performed even when jumper W201 is installed in the SKIP SELF TEST position of connector P201 on the GPIB board see paragraph 4 16 The other eight tests are skipped not performed if W201 is installed in the SKIP SELF TEST position If any board fails power on sel
154. e test procedures outlined a Perform the turn on and checkout procedures given in Section III paragraphs 3 3 thru 3 9 of the Operating Manual These procedures include a power on self test b Perform the performance tests listed below on each output of your supply Voltage Programming and Readback Accuracy paragraph 3 12 CV Load Effect paragraph 3 13 CV Noise paragraph 3 15 Overvoltage Protection Tests paragraph 3 18 Current Programming and Readback Accuracy paragraph 3 21 CC Load Effect paragraph 3 23 3 4 PERFORMANCE TESTS 3 5 Introduction The following paragraphs provide test procedures for verifying the supply s compliance with the specifications listed in Table 1 2 of the Operating manual The procedures cover all models in the series of Multiple Output Power Supplies The performance test procedures must be performed on each output Figure 3 1 shows the outputs present and output ranges on each model The test procedures that follow give settings and results for each type of output that may be tested There are two types of outputs 25 Watt and 50 Watt Make sure that you use the test settings and results listed for the particular output Table 3 1 Test Equipment Required for Verification Required Characteristics Recommended Model GPIB Controller Full GPIB capabilities Agilent 9825 85 or series 200 300 computer Dual Channel Sensitivity 1 mV Bandwidth 20 MHz Input 50 ohms and 10 Meg True
155. ect the keypad and display ribbon cables from P202 and P203 on the GPIB board Ensure that these cables are not pinched between the front panel and the chassis when reassembling b Remove the rack ears or vinyl trim from the sides of the front panel C Remevhe two screw on ach sideof frat panel d Slide he forward 4 11 Chassis Mounted Components The power transformer is fastened to a mounting bracket by mounting screws flat washers and shoulder washers Before removing the attaching hardware disconnect the power cable leads at the transformer To avoid breaking the transformer tabs lugs do not bend transformer tabs When disconnecting a lead pull the lead connector straight back from the tab When reconnecting a lead push the connector straight forward onto the transformer tab Do not flex the leads or tabs when making connections or disconnections When replacing the transformer refer to the label on the transformer to ensure you reconnect the leads correctly You can also refer to Figure 6 1 which shows all AC connections schematically for each of the models The fan and fan guard are secured to the chassis by mounting screws flat washers and nuts Remove this hardware disconnect the ac connector on the fan assembly and lift the fan from the unit Table 4 1 Test E Purpose uip Digital Voltmeter Digital Voltmeter Check various voltage levels various Check various voltage level
156. ed as shown in Figure 3 3 with the DVM connected across the S and 5 terminals the load switch closed and the short switch opened b Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel c Program the selected output to 50 volts and 0 515Amps 25W or 1 03 Amps 50W d Adjust the load for 0 5 Amps 25W or 1 08 Amps 50W as read on the display Check that the CV annunciator is on e Set the temperature chamber to 30 degrees C and allow 30 minutes for the output to stabilize f Record the output voltage on the DVM g Readback the output voltage over the GPIB and record the value h Increase the temperature to 40 degrees C and allow 30 minutes for the output to stabilize i Repeat steps f g Note the difference between the values read before and after the temperature change The difference between the output voltage DVM readings should be less than 16 mV The difference between the readback voltage should be less than the change in output 15 mV Repeat steps a through I for each output in your supply 3 35 Output Current and Readback Current TC a Repeatsteps a through d of paragraph 3 34 b Set the temperature chamber to 30 degrees C and allow 30 minutes for the output to stabilize c Record the output current DVM reading 0 1 Shunt resistance d Readback the output current over the GPIB and record the value e Increase the temperature to 40 degrees C and
157. ed from the supply s front panel In addition to the ON OFF switch already mentioned the front panel contains an LCD display and a keypad The LCD display consists of an alphanumeric display and status annunciators The LCD normally displays the measured output voltage and current of the selected output When programming an output from the front panel keypad the selected output channel the function being programmed and the present value will be displayed The annunciators indicate which output channel has been selected and give GPIB and power supply status information The keypad allows control of the supply s system functions as well as individual control of each output channel Detailed instructions on using the front panel s display and keypad are given in the Operating Manual 2 6 Output Boards The Agilent 6625A and 6628A contain two output boards and the Agilent 6626A and 6629A contain four output boards The output combinations that correspond to each model are shown in Figure 2 1 Each isolated output can supply power in two ranges as shown in Figure 2 2 This flexibility allows you to use the same output to power loads with different voltage and current requirements The output ranges and operating characteristics of each output are described in greater detail in Section IV of the Operating Manual As shown in Figure 2 1 each output board contains a rectifier filter power module control circuit secondary interface circuit
158. els have this error the problem is probably on the GPIB board If only a particular output channel has the error follow the board isolation pro cedures in Figure 4 5 to isolate the problem to the defective output board the GPIB board or the cable between the specified output board and the GPIB board Same as error code 11 Same as error code 11 Same as error code 11 The supply s model number cannot be found The GPIB board may be defective see paragraph 4 18 or the supply s model number may require reprogramming using the MODEL command see paragraph 4 21 Supply requires recalibration An unexplained EEPROM error has occurred Recalibrate as described in Appendix A of the Operating Manual If recalibration doesn t fix the problem troubleshoot the GPIB board see paragraph 4 18 Jumper W201 on the GPIB board is in the SKIP SELF TEST position of connec tor P201 see Figure 4 2 Install W201 in the NORM RUN position and carry out self test if desired An error has occurred during calibration This may result if an incorrect calibra tion sequence is done or if a CAL command is sent with CAL MODE off If recalibration see Appendix A in Operating Manual doesn t fix the problem there may be a hardware problem see GPIB troubleshooting paragraph 4 18 See CAUTION under CAL LOCK Error 5 can occur during calibration 4 10 Table 4 5 ERROR Codes and Messages continued Message Error Code ERR key ERR query Ex
159. er types of fasteners will damage threaded inserts When removing or installing screws use a No 1 or a No 2 Pozidriv screwdriver 4 4 Top Cover Removal The top cover must be removed to gain access to the assemblies inside the supply To remove the cover proceed as follows a Remove the four screws which hold the carrying straps b Spread the bottom rear of the cover slightly and pull back to disengage it from the front panel c Remove the top cover Note that you can use the top cover assembly as a support when you open the top chassis in the next procedure 4 5 Gaining Access to Assemblies in the Supply As shown in Figure 4 1 each power supply model contains an GPIB board and at least two output boards The output boards are mounted on an upper chassis assembly and in the lower section of the main chassis The upper chassis assembly is hinged and its output boards are mounted with the components facing down The output board s in the main chassis are mounted with the components facing up To gain access to the output boards the GPIB board power transformer and other components inside the supply proceed as follows a Remove four screws located on top of the chassis near the front b Remove three screws from top left side and two screws from rear which hold the upper chassis to the main chassis c Open the hinged upper chassis by lifting it from the left side This will give you access to the components on the outpu
160. es the conduction of the series regulator The interface circuit on the output board receives digital signals from the GPIB board and converts them to analog signals reference voltages which are sent to the control circuit to program the output voltage and current The output boards can be commanded to send measurement and status data back to the GPIB controller and or to the display on the front panel The data is sent back via the secondary interface circuit and the appropriate circuits on the GPIB board The output board is able to sink current as well as source current Current sink limits are fixed at values slightly higher than the maximum current source limit for the particular output voltage operating point See Figure 2 7 for typical current source and sink characteristics The output board circuits are described in greater in paragraph 2 24 2 7 GPIB BOARD FIGURE 2 3 Figure 2 3 illustrates the major circuits and signal flow on the GPIB board Complete circuit details are shown on the functional schematic in the rear of this manual The functional names on the block diagram correspond with those on the schematic so that the diagrams can be correlated As shown in Figure 2 3 the major circuits consist of the GPIB interface the system micro computer the output boards interface and the front panel interface circuit 2 8 Interface These circuits consist of the GPIB bus connector J201 transceivers U203 for
161. est N02 vite RN 4 19 4 85 GPIB Board 4 20 429 Board ree des e Ca debits 4 21 4 10 GPIB Board S A Test gta AA 4 22 4211 ypas EE EUER ERE ME EE Ere OR 4 23 4512 GPIB Board S A TESUNO Fe s AO A AAA 4 24 4 13 GPIB Board S As Test cs oo dee RT Tet HE VIS HERR APUD 4 25 414 Keyboard tee 4 27 4 15 Microcomputer 0312 Signal Measurements During the Self Exercise Routine 00000011 4 44 4 16 U368 SignaL Levels O 4 45 4 17 Signal Processor 0327 Signal Levels eie tpe tete teda SSE a Pasa 4 47 4 18 Typical Power Module Voltage 4 49 4 19 Miscellaneous Trouble Symptoms z gue ce epi Ul 4 50 5 1 Output Board Configurations eod ue bates re E 5 1 5 2 Reference Designators dt eee er tee A A APA O Gab does Ex a rare vai RR EU i 5 1 Se tate Mee Wiebe ech goer ge Saa uod 5 2 54
162. eturn the supply to normal operation the AC must be cycled off then back on Immediately following turn on the RAM and ROM self tests on U312 are performed provided that the PCLR signal from the signal processor U327 goes High Then the self exercise routine begins This routine runs independently of the GP IB board which is ignored by an output board operating in this mode During the routine the display indicates HDWERR CH lt ch gt as if that output board were defective The self exercise routine is used in the troubleshooting procedures provided on sheets 5 and 6 of Figure 4 8 The output voltage and current limit are repetitively programmed to full scale values during the self exercise routine Be sure that no load of any kind is connected to the output terminals when operating in this mode Also note that the POV DISABLE line U312 pin 23 is High which disables the programmable OV the fixed overvoltage circuit can still operate In the self exercise routine microcomputer U312 repetitively programs each of the DAC s U313 U321 and U363 Each DAC is programmed from zero to 5V This is accomplished by starting with the LSB and turning on each successive bit The DAC output is programmed back to zero Table 4 15 lists the signals that should be present on pins 1 through 28 of U312 during the self exercise routine Figure 4 9 illustrates the waveforms that should be observed at various points on the output board durin
163. f a variable load resistor and switches The electronic load 15 considerably easier to use than load resistors It eliminates the need for connecting resistors or rheostats in parallel to handle power it is much more stable than a carbon pile load and it makes easy work of switching between load conditions as is required for the load regulation and load transient response tests Substitution of the electronic load requires minor changes to the test procedures in this section 3 8 Current Monitoring Resistor To eliminate output current measurement error caused by voltage drops in the leads and connections connect the current monitoring resistor between the V and the load as a four terminal device Figure 3 2 shows the connections Connect the current monitoring leads inside the load lead connections directly at the monitoring points on the resistor element MONITORING TERMINALS Figure 3 2 Current Monitoring Resistor Setup 3 9 GPIB Controller Most performance tests can be performed using only the front panel keypad however an GPIB controller is required to perform the voltage and current readback accuracy tests The test procedures are written assuming that you know how to program the supply remotely from an GPIB controller or locally using the control keys and indicators on the supply s front panel Complete instructions on remote and local programming are given in the Operating Manual NOTE In the test programs that follo
164. f test the OUTPUT ENABLE line U312 22 is held high which keeps the ON OFF line U327 25 low For this condition the supply will not respond over the GPIB and none of the output boards will operate When W201 is installed in the SKIP SELF TEST position in service connector P201 o the GPIB board a circuit problem that could have been detected with the self test will no longer cause the GPIB board to prevent the outputs from operating Table 4 3 Tests Performed at Power On Test Board Tested Failed Test With W201 in SKIP Error Message SELF TEST Position RAM Test ROM Test 8291 Timer CVDAC CLDAC OVDAC Fuse RAM ROM Note that error number 22 SKIP SELF TEST is initially generated when W201 is in the SKIP SELF TEST position This error is cleared when read However if an output board fails the output board RAM or ROM tests which are performed regardless of the W201 position error number 11 12 13 or 14 HDW ERR CH lt ch gt is generated and will be regenerated after the error is read since the problem still exists Table 4 4 lists all of the self test error messages that can appear on the front panel display when power is first turned on Each message is explained and a troubleshooting procedure is recommended This table is to be used in conjunction with Figure 4 5 and other troubleshooting flow charts provided in this section 4 16 Connector P201 Jumper Positions The GPIB board contains a connector P201 see Figu
165. fferences between the models are given as required The descriptions provide a basic understanding of circuit operation and are intended as an aid in troubleshooting It is assumed in the following discussions that you are familiar with the operating and programming instructions presented in the Operating Manual Agilent Part No 06626 90001 2 2 OVERALL BLOCK DIAGRAM DESCRIPTION FIGURE 2 1 Figure 2 1 is a block diagram that illustrates the major assemblies contained within the power supply As shown in the figure each supply includes ac input circuits an GPIB board front panel display and keyboard and two or more output boards 2 3 AC Input Circuit The ac input circuit consists of a line module on the rear panel of supply front panel ON OFF switch S1 power transformer T1 located in the front of the chassis and a cooling fan located in the rear of the chassis The line module contains a voltage selector card that selects the applicable ac input voltage 100 Vac 120 Vac 220 Vac or 240 Vac The voltage card selection must match the nominal line voltage that is connected to the unit The line module also contains the main fuse Fl An 8 A fuse normal blow must be installed for a 100 120 VAC input a4 fuse normal blow must be installed for a 220 240 VAC input The ac input is applied to the power transformer when 51 is Depending on the line module setting the 120 Vac cooling fan either runs directly from the line modul
166. ffers U212 place the serial data from each output board and the EEPROM on the supply s system microcomputer data bus lines when chip select C53 is decoded Serial data from output boards 1 4 appears on data bus lines D0 D3 respectively and EEPROM serial output data appears on data bus line D7 Logic 0 5 will always appear on data bus lines D4 D6 when CS3 is decoded because these buffer inputs are connected to COMMON buffer output are held in the high impedance state when CS3 is not decoded 2 18 Data Latches These stages U213 are edge triggered D type flip flops On the rising edge of the 52 chip select the output of each stage will be set to the logic state that is present on the associated data bus line Data bus line D0 D3 are the serial data input lines for output boards 1 4 respectively Data bus line D4 controls the TIMER ENABLE signal line to the real time clock circuit D5 is the chip select line for the EEPROM D6 is the clock signal for the and D7 is the data input line for the EEPROM The data that is transferred between the GPIB board and the output boards up to 4 passes through optical isolators located on each output board 2 19 EEPROM This 4 K bit serial EEPROM electrically erasable programmable memory stores the power supply s GPIB address and model number as well as the constants used in calibrating the supply The EEPROM U230 is nonvolatile allowing it to retain the stored information
167. ffset to compensate for the voltage drop across the current monitor resistor The POV DISABLE signal inhibits the programmable OV function from affecting the OV DRIVE signal 2 The voltage from the V output terminal to the S terminal or from the S terminal to the V output terminal exceeds 10 V applies to remote sensing only 3 Atrip signal is received on the output s OV terminal 4 The output s fixed overvoltage circuit is activated Power On Start Up At power on the output of the turn on comparator circuit BIAS TRIP input signal to U327 is initially low which holds the PCLR and ON OFF signals low With PCLR low the microcomputer is held in the reset state With ON OFF low the power control circuits are held off preventing any power from reaching the output terminals The turn on comparator circuit part of U325 monitors the unregulated bias supply to determine if it is high enough to guarantee regulation by the three pin regulators The medium rail voltage is also monitored to ensure that it is above the minimum level required for proper operation of the power module When these two conditions are met the BIAS TRIP line is allowed to go high approximately 0 7 V Then after a delay of approximately 0 3 seconds provided by an external delay capacitor C346 the PCLR signal goes high allowing the microcomputer to complete its initialization routine and set the OUTPUT ENABLE line low This allows the ON OFF signal to
168. fic signature analyzer and jumper connections for each test are given in the applicable table a Gain access to the GPIB board components as described in paragraph 4 19 Be sure that the power supply is turned off before continuing with the following steps b Connect jumper W201 in the SIG ANALYSIS position across pins 5 and 6 of connector P201 as shown in Figure 4 7 c Short pins 1 and 4 together on connectors P205 through P208 as shown in Figure 4 7 d Check that jumper pack W202 is in the proper position specified by the particular S A test Figure 4 7 shows two operating positions normal run position and NOP no operation position W202 is a 16 pin jumper pack To select the normal run position W202 is plugged into 16 pin socket J202 To select the NOP position W202 is connected between 8 pin socket J203 and pins 1 8 of 16 pin socket J202 see Figure 4 7 e Set the signature analyzer START STOP CLOCK GND and edge settings as described in the applicable S A Test table f Turn the power supply on and use the signature analyzer probe to take signatures at the applicable IC test points see Table 4 6 through 4 13 g Upon completion of the S A test remove short circuit connections from pins 1 and 4 on P205 P208 and return jumpers W201 and W202 to their normal run positions 4 24 Firmware Revisions The ROM chip U206 on the GPIB board is identified with a label that specifies the revision of your supply s
169. firmware Alternatively if the GPIB board is operating properly the command can be used to query the revision date As stated in paragraph 4 22 the revision date for firmware revision A 00 is 2839 where 28 specifies 1988 and 39 is the week number To query the revision date of the firmware ROM in your supply run the short program list below 10 OUTPUT 705 ROM 20 ENTER 705 A 30 DISP A 40 END The computer should display the revision date e g 2839 Note that the signatures in Table 4 6 GPIB Board S A Test No 2 for the ROM are for revision A 00 and will be different for different revisions Signautres for other date codes may be found in the change page accompanying this manual The secondary ROM revision can be queried by replacing ROM with SROM in fine 10 TURN OFF THE SUPPLY DISCONNECT ALL LOADS AND CONNECT S TO V AND S TO TURN ON SUPPLY CHECK LINE FUSE F LINE VOLTAGE SWITCH Si AND FAN Bi SEE FIG 6 1 PASSED NO SELF TEST TO SHEE YES USING FRONT PANEL CONTROLS SELECT AN OUTPUT CHANNEL AND PROGRAM THE OUTPUT VOLTAGE AND CURRENT WITHIN THE ACCEPTABLE RANGE OF THE OUTPUT PRESS ERR KEY AND OBSERVE THE DISPLAY CALIBRATE THE OUTPUT SEE APPENDIX R IN THE OPERATING MANUAL SEE ERROR MESSAGE TROUBLE SHOOTING TABLE 4 5 NOTE THE OUTPUT CHANNEL NO THAT FRILED DID NO TROUBLESHOOT THE OUTPUT BOARD ALL CHANNELS SEE PARRA 4 25 FAIL Yes U
170. from having reverse voltages applied 2 42 Peak Current Limit This circuit Q321 Q322 R407 0 U340 quickly limits the amount of current through the series regulator elements in the power module It is activated when the output current exceeds the full scale value about 75 in either the sourcing or the sinking direction The series pass regulator in power module U338 is connected in series with an external resistor R407 When the voltage across R407 exceeds a diode drop in either direction the peak current limit circuit is activated and limits the conduction of the series pass transistor element or current sink transistor This circuit reacts much faster than the or current control circuits see paragraph 2 47 When the peak current limit circuit is activated in the current source direction not only will the conduction of the series regulator be limited but the current control circuit U376 will be quickly activated through P O U340 CR341 U376 and R405 to take control of the current limiting action 2 43 Bleed Circuit This circuit Q341 R456 etc connected from V to 7 V provides a fixed current of about 15 mA through the series pass elements in the power module so that they are never completely turned off The bleed circuit is activated via the power on circuit when the ON OFF signal is high The bleed circuit maintains stability with large output capacitors under light loading conditions and helps to keep the ou
171. g Speed Test Waveforms supply s outputs have been checked 5 aaa z Figure 3 12 OV External Trip Test Connections Table 3 3 Performance Test Record for Agilent 6625A 6628A No Pre Cal Post Cal Serial Temperature Test Performed by Humidity Dat ne Test Specifications are shown in parenthesis OUTPUT 1 OUTPUT 2 3 12 CV PROGRAMMING 0 Volts Output Accuracy DVM Reading 25W High Range 0 10 mV Low Range 0 1 5 mV 50W High Range 0 10 mV Low Range 0 3 mV Display and Readback Accuracy 25W High Range DVM 10 mV Low Range DVM 2 mV 50W High Range DVM 10 mV Low Range DVM 3 5 mV CV PROGRAMMING Full Scale Output Accuracy DVM Reading 25W High Range 50 V 18 mV Low Range 7 V 2 6 mV 50W High Range 50 V 18 mV Low Range 16 V 5 5 mV Display and Readback Accuracy 25W High Range DVM 18 mV Low Range DVM 3 1 mV 50W High Range DVM 18 mV Low Range DVM 6 06 mV 315 Cv LOAD EFFECT Saw _ 3 14 CV SOURCE EFFECT 5 mV EN CV NOISE PARD Peak to Peak 3 mV RMS 500 TRANSIENT RECOVERY 75 m 05 mV A TURN ON OFF OVERSHOOT 0 V 4 100 mV OVERVOLTAGE PROTECTION programmable 49 V 48 44 to 49 55V 2 2 3 20 CC PROGRAMMING 0 Amps Output Accuracy Io 25W High Range 0 mA Low Rang
172. g the self exercise routine The waveforms shown on these figures are referenced in the troubleshooting procedures of Figure 4 8 Figure 4 9 shows what the output of the CV DAC U360 pins 6 CC DAC U361 pin6 and Readback DAC U362 pin 6 should look like 19 steps total in waveform Figure 4 9 shows what the output 6the OV DAC U319D pin14 should look like 8 steps total All inputs and outputs of U367 and U368 Programming and readback range address decoders are execised The output of the analog multiplexer U323 may be exercised using the VMUX command CHECK THAT 5V 15 AND BIRS VOLTAGES ARE WITHIN THE RANGE SPECIFIED HERE SEE TABLE 4 17 CHECK THAT THE REFERENCE VOLTAGES VREFA VREFB VREFC VREFD ARE 10 5 SEE FIG 6 3 SHEET 1 CHECK THAT THE HIGH MEDIUM AND LOW RAIL VOLTAGES ARE CORRECT SEE TABLE 4 18 CHECK THAT 5V IS PRESENT ACROSS P382 3 5V AND P382 2 GND BIRS SUPPLY VOLTAGES AND CURRENTS ANY DAC ERRORS O ES DISPLAYED DRC DeC NO DAC Figure 4 8 Sheet 1 Output Board Troubleshooting 4 29 N N N MERSURE THE BIAS TRIP VOLTAGE RT U327 27 IT SHOULD BE 85 APPROX gt CHECK FOR_RPPROX 24 ON ERCH d XFMR BIRS WINDING TO S AN AND 2381 3EVDG PROBLEM CRUSED BY UNREG BIRS VOLTAGE BELOW ABOUT 19 5 MEDIUM RAIL VOLTAGE BELOW ABOUT 29 5V OR BIAS TRIP CIRCUIT DEFECTIV
173. gative current limit mode As shown in the simplified schematic of figure 2 6 the negative current limit circuit consist mainly of an open collector toggle comparator part of U351 and CL error amplifier U350 U375 acts as a clamp to ensure the CL Summing junction 53 does not exceed 10mV 2 15 The voltage drop SHUNT which is a negative voltage when sinking current across the current monitoring resistor R408 is applied to summing junction S3 along with a reference voltage Based on this summing action error amplifier U350 generates the CL control signal which is applied through diode CR354 to control the base drive circuit For the 50W outputs comparator U351 toggles the reference voltage between the 1 1 and 2 2 Amp range levels This is required because the output board has two fixed ranges a high voltage low current and a low voltage high current As you can see Fig 2 7 a 50W output can sink up to 2 2A when its output is below 26V and up to 1 1 A when its output is approximately 26V U351 constantly monitors the output voltage in order to provide the proper reference voltage to the summing junction of U350 If the output voltage is in the high range the open collector output of U351 will be near ground thereby dividing down the VREF voltage to summing junction S3 resulting in a lower sink current limit of 1 1A If the output voltage is in the low range the collector output of U351 will be 15V resulting i
174. ge on U327 14 against Table 4 16 see paragraph 4 30 Check R355 and C345 If the over temperature condition occurs rapidly after application of output load power module U338 may be defective Fuse F303 in the output Check for shorted capacitor s C375 C376 from power module pin 5 to common return line blows after being Check for open CR327 Check power module U338 replaced 4 51 P70 U327 STATUS MONITOR CIRCUIT STATUS SELECT CV LOOP LOW MEDIUM LOW LOW LOW LOW OR MED LOW HIGH LOW LOW LOW LOW CARE HIGH LOW MEDIUM LEVELS GIVEN IN TABLE 4 16 STATUS DECODING STATUS INPUTS CL LOOP CL LOO X HIGH HIGH X X HIGH LOW OV SENSE X x RESULTING OUTPUT CVO LOW CV MODE CLO LOW CC MODE CLO LOW CC MODE UNREG LOW UNR MODE UNREG LOW UNR MODE OV HIGH OVERVOLTAGE OT HIGH OVERTEMPERATURE ALL 6 OUTPUTS OPEN CIRCUIT FRONT PANEL INDICATION CV ANNUNCIATOR CC ANNUNCIATOR CC ANNUNCIATOR UNR ANNUNCIATOR UNR ANNUNCIATOR OVERVOLTAGE MESSAGE MESSAGE NO CHANGE Figure 4 17 Signal Processor U327 Status Monitor Circuit Simplified Schematic Diagram OPERATING MANUAL PARR 4 5 FOR A DISCUSSION OF OPERATING STATUS SET UP SCOPE TO TROUBLESHOOT STATUS PROBLEMS RS DESCRIBED IN PARA 4 32 DURING THE INTERVAL WHEN STATUS SELECT IS LOW CHECK ALL SIX SEE FIGURE 4
175. gnal will again fire the SCR and disable the output Note that in addition to resetting the SCR the OVRST command will program the output to the settings that existed before the OV occurred Down Programmer Separate transistors in the power module are used to sink output current and are capable of rapidly down programming the output voltage to about 2 V An external FET down programmer circuit see paragraph 2 49 is connected across the output to continue down programming the output voltage below 2 V Overtemperature Protection The power module also contains an overtemperature circuit that consists of negative temperature coefficient thermistor that senses the power module s temperature When the power module s temperature rises enough to reduce the THERM input resistance to about 8 K ohms the thermistor drops below 2 5 V approximately notifying the signal processor that an overtemperature OT condition has occurred The signal processor then relays this information to the microprocessor which will shutdown the particular output with the overtemperature condition The output will be restored 30 seconds after a safe operating temperature is reached Reverse Output Voltage Protection Diode The power module contains a diode with its cathode connected to the COLLECTOR output and its anode connected to the power module COMMON This diode is essentially connected across the power supply s output terminals to protect the output
176. gure 4 16 and the power supply passes its self test the microcomputer U312 causes this pin to go Low With PCLR High and enabling the output With OUTPUT ENABLE High ON OFF is Low and the output will not supply power ON OFF pin 25 This output goes High when PCLR pin 26 is High and OUT ENABLE pin 24 is Low see Figure 4 16 When High the ON OFF line enables the control circuits and current sources of the output board which allows power to reach the output terminals PCLR pin 26 This output goes High when DELAY CAP pin 23 goes High see Figure 4 16 When PCLR is High and OUTPUT ENABLE pin 24 is Low ON OFF pin 25 goes High Note that BIAS TRIP goes High when both the unregulated bias supply voltage and the medium rail voltage are high enough 15 V pin 28 The 15 V bias voltage can range from 15 55 V to 13 98 V 4 32 Troubleshooting Status Problems An output will report its operating status CV CC CC OV OT and UNR when queried to do so see paragraph 5 25 in the Operating Manual The front panel also indicates the present status of the output When an output appears to operate properly but incorrect or multiple status is reported the problem may be caused by the status monitor circuit section of U327 microcomputer U312 or a short on the data lines between these two IC s Note however that certain load transients can cause a temporary multiple status condition to exist and this is
177. hannel B trace to the top horizontal line of the oscilloscope and move the input switch to the DC position Adjust the bucking supply until the Channel B trace is as close as possible within 1 division to the top horizontal line and then use the scope vertical adjust to fine adjust the trace to the top horizontal line Program the output voltage in a loop which alternately programs the output voltage between 0 4 V and 50 V by running the following program 10 OUTPUT 705 ISET ch lt 0 515 25W or 1 03 50W 20 OUTPUT 705 VSET ch 50 30 WAIT 0 05 TIME CONSTANT USES 40 OUTPUT 705 VSET ch 4 50 WAIT 0 05 Figure 3 8 CV Down Programming Speed 60 GOTO 20 Test Waveforms 70 END 3 38 CV UP Programming Speed This test measures the time required for the output voltage to rise to 6376 of the NOTE high range full scale voltage time constant Also measured is the time the output takes to change from 4 volts to full scale and settle within 50 mV response time The tested output s CV annnciator should remain on at all times while the test is in progress a Turn off the supply and connect the output to be tested as shown in Figure 3 9 h Observe Channel A on the oscilloscope and adjust for a stationary waveform by using Channel A as the trigger source set to trigger on a positive edge Be sure to trigger as close as possible to the time when the output voltage just begins to rise i On Channel A obse
178. hould be within the limits specified below for the particular output type being tested Prog Accuracy Display Accuracy Output DVM Reading 30 1 Front Panel LCD 25W 0 15 A Io 15 4A 50W 0 185 pA lo 250 pA Read back the output current from the selected channel over the GPIB to the controller by running the following program 10 OUTPUT 750 IOUT lt ch gt 20 ENTER 705 A 30 DISP A 40 END Record the value displayed on the controller This value should be within the limits specified below using the lo reading noted in step d Readback Accuracy Output Controller Display 25W Io 15 pA 50W lo 250 pA Program the selected output s voltage to 5 V and the current to the Low Range Full Scale Current value by sending the strings VSET lt ch gt 5 lt ch gt lt 015 25W or 2 50W gt Divide the voltage drop across the current monitoring resistor by the value 0 1 to convert to amps Record this value Io Note also the current reading on the front panel display The readings should be within the limits specified below for the particular output type being tested Prog Accuracy Display Accuracy Output lo DVM Reading 0 1 Front Panel LCD 25W 15 mA 21 A lo 20 pA 50W 2 265 pA 330 pA Run the program listed in step e Record the value displayed by the controller This value should be within the limits specified below using the Io reading noted in step h Readback Accuracy
179. icated level must have occurred e g THERM pin 14 is HIGH only when the voltage increases to a level gt 2 8 V 0 15 V 6 XV Indicates that hysteresis is involved in the trip voltage level and a transition from a higher voltage down to the indicated level must have occurred e g THERM pin 14 is LOW only when the voltage decreases to a level 2 5 V 0 15 V 4 47 OV COMP 2 The OV COMP overvoltage comparator input signal when High causes OV DRIVE pin 6 to be High gt 8 V if POV DISABLE pin 3 is Low POV DISABLE pin 3 The POV DISABLE programmed overvoltage disable input signal when High prevents OV COMP pin 2 from causing OV DRIVE pin 6 to be High It does not prevent OV TRIP pin 4 from causing OV Drive to be High OV TRIP pin 4 This input signal when High causes OV DRIVE pin 6 to be High gt 11 V independent of POV DISABLE pin 3 Common pin 5 Along with pin 22 this is a common return for the bias supplies OV DRIVE pin 6 This output signal is a function of inputs OV COMP POV DISABLE and OV TRIP When OV DRIVE goes High it fires the SCR in the power module The OV DRIVE pin voltage will be gt 8 V when tripped from OV COMP and gt 11 V when tripped from OV TRIP see Figure 4 15 STATUS RESET pin 7 This input pin when High causes four internal flip flops to be reset The four flip flops are used to catch and hold the occurrence of four status conditions CV
180. igh voltage and current ranges Using this information U367 sets analog switches U364 for the proper divider tap for the desired range full DAC output O to 10 V for high range or a portion of the 10 V for the low range 2 34 Readback Range Switching U365 U366 U368 provide readback of the output of the power supply to the analog multiplexer U323 except for the 50 V range VFS Readback latch U368 receives information via data lines DOO and DO1 which set up monitor switches U365 and gain select switches U366 to readback the output parameters 2 35 Signal Processor This special purpose IC U327 processes both analog and digital signals to interface the microcomputer with the power mesh and control circuits The circuits can be functionally divided into status monitor overvoltage detector and driver and power on start up circuits Status Monitor this circuit consists of comparators to monitor the control loops logic to decode these input line and flip flops to catch and hold changes The inputs to the status comparators are the CV LOOP CL LOOP and CL LOOP signals from the power control circuits see Figure 2 5 The outputs of the comparators are combined in logic circuits is decoded if the output is not regulated by a CV or CL control loop The flip flops are set by any transition into a decoded state This generates a record of whether any of the conditions CV CL CL UNREG existed since the last t
181. igure 2 9 the trip signal enters at the OV terminals and is coupled through pulse transformer T301 diode CR360 and the overvoltage detector circuit to generate OV GATE and shut down the supply 2 51 Guard Bands Guard Bands are employed on the Shunt track the Sense track and Common track pin 3 of R408 on the PC board The guard bands shield these traces ensuring they are not affected by DC leakage currents from adjacent tracks 6192 ISEH dIML O 3LOWGY 181 0 9 dIMLI AO 31043 9181 AO 8019341341 3 AL TOANIAO U3MOd OL 3189 AO 0 4 1 9231084 3081 OA83AO Figure 2 9 Overvoltage Protection Circuits Simplified Schematic 2 17 Section III VERIFICATION 3 1 INTRODUCTION This section contains test procedures that check the operation of the power supply Four types of procedures are provided Operation Verification Tests Performance Tests Extended Tests and Temperature Coefficient Tests The Operation Verification Tests comprise a short procedure to verity that the supply is performing properly without testing all specified parameters The Performance Tests provide a more complete test of the supply by testing most of the specifications listed in Table 1 1 in the Operating Manual Agilent Part No 06626 90001 The Extended and Temperature Coefficient tests are similar to the Performance tests except that they are conducted ina controlled environment and require a longer
182. ime the flip flops were reset The STATUS RESET input line from the microcomputer resets the flip flops THERM inputs The THERM signal is received from the power module s in the power mesh see Figure 2 5 and indicates when an overtemperature condition exists Note that when the microcomputer senses the overtemperature OT condition via data bus line D4 it shuts down the output This circuit resets automatically and restores the output approximately 30 seconds after the temperature drops sufficiently for safe operation The OV SENSE input signal indicates when the output s overvoltage detector circuit has been tripped and the output has been shut down see overvoltage detector description and OV outputs of the status monitor Note that the OT and OV status are not held in flip flops of status monitor s returned to the microcomputer via data bus lines D0 D5 when chip select CS0 is decoded 5110812 8 3 2058 AD Figure 2 4 Output Board Secondary Interface Circuits Block Diagram 2 9 Overvoltage Detector This circuit generates the OV DRIVE signal which shorts the output by firing the SCR crowbar within the power module on the output if any of the following conditions are present 1 The output at the V terminal exceeds the programmed OV trip point OV PROG Note that the I READBACK signal provides an o
183. ion Mfg Mfg No Code Part No C368 70 0180 0393 CAPACITOR FXD 39uF 10 10VDC TA 56289 150D396X9010B2 C372 0160 4830 CAPACITOR FXD 2200PF 10 100VDC CER 16299 C373 74 NOT USED C375 76 0180 3804 CAPACITOR FXD 474F 20 35VDC 56289 C377 80 NOT USED C381 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C382 NOT USED C383 84 0160 4791 CAPACITOR FXD 10PF 5 100VDC CER 16299 C385 0160 4812 CAPACITOR FXD 220PF 5 100VDC CER 16299 C386 0160 4820 CAPACITOR FXD 1800PF 5 100VDC CER 16299 C387 0160 4832 CAPACITOR FXD 01 10 100VDC CER 16299 C388 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C389 0160 5098 CAPACITOR FXD 22uF 10 50VDC CER 16299 CAC05X7R224J050A C390 NOT USED C391 0160 4812 CAPACITOR FXD 220PF 5 100VDC CER 16299 C392 0160 5166 CAPACITOR FXD 015uF 20 100VDC CER 16299 C393 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C394 NOT USED C395 0160 5166 CAPACITOR FXD 015uF 20 100VDC CER 16299 C396 0160 4832 CAPACITOR FXD 01 10 100VDC CER 16299 C397 0160 5166 CAPACITOR FXD 015uF 20 100VDC CER 16299 C398 0160 5409 CAPACITOR FXD 3000PF 5 50VDC CER 16299 C399 0160 4787 CAPACITOR FXD 22PF 5 100VDC CER 16299 C400 0160 4830 CAPACITOR FXD 2200PF x 1096 100VDC CER 16299 C401 0160 4801 CAPACITOR FXD 100PF 5 100VDC CER 16299 C402 0160 7319 CAPACITOR FXD OF 84411 C403 04 NOT USED C405 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C406 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C407 08 NOT USED
184. l circuits to be processed before they are sent on to the GPIB board and then to the GPIB controller and or the front panel The following paragraphs describe the interface circuits shown in Figure 2 4 2 26 Microcomputer This 8 bit microcomputer U312 contains a CPU ROM and RAM These internal circuits process all data that is transferred between the GPIB board and the power mesh and control circuits on the output board GPIB board data is transferred serially via optical isolators which connect incoming data to an input port on the microcomputer and outgoing data to an output port on the microcomputer On the output board side the microcomputer uses an 8 bit parallel bi directional data bus to program DACs which control the output voltage output current overvoltage setting and sets the readback DAC Various status and operating conditions are read back on the data bus The microcomputer also generates address and control signals which are used by other interface circuits The interrupt input to the microcomputer is used in conjunction with readback monitor switches U365 U366 and U368 analog multiplexer U323 and DAC U321 to perform a successive approximation A D conversion in order to readback output voltage and current values as well as various test point voltages 2 27 Address Decoder This circuit U320 decodes addresses sent by the microcomputer and generates the appropriate chip select signal CSO 56 to select which
185. lent Technologies Australia Pty Ltd 347 Burwood Highway Forest Hill Victoria 3131 tel 1 800 629 485 Australia fax 61 3 9272 0749 tel 0 800 738 378 New Zealand fax 64 4 802 6881 Asia Pacific Agilent Technologies 24 F Cityplaza One 1111 King s Road Taikoo Shing Hong Kong tel 852 3197 7777 fax 852 2506 9284
186. ltiplexer U323 Signal Processor U327 Power Module U338 U339 and Microcomputer 312 4 26 Test Setup The following test setup allows you to access the components on the output board and perform the troubleshooting procedures a Disconnect the line cord b Gain access to the output board as described in paragraphs 4 3 through 4 5 c Make sure that jumper W201 P201 and W202 jumper pack on the GPIB board are installed in their normal run positions See Figure 4 2 d Check that S is connected to V and S is connected to V on the output terminal block e Connect the line cord 4 27 Post Repair Calibration If the output board is replaced the associated output channel must be recalibrated as described in Appendix A of the Operating Manual If certain components in the output circuits DAC S voltage control circuit or current control circuit or the readback circuits e g readback buffers DAC amplifier signal comparator on the output board are replaced the associated output channel must be recalibrat ed as described in Appedix A of the Operating Manual 4 28 4 28 Self Exercise Routine on an Output Board The output board can be put into a mode that exercises the microcomputer U312 and all of the DAC s for ease of troubleshooting In order to enter this mode U312 pin 6 5 must be tied to pin 7 timer before the supply is turned on This short may be removed once the routine starts 1 sec To r
187. mable Read Only Memory Electrolytic Erasable Programmable Read Only Memory Field Effect Transistor Flip Flop Full Wave Fixed Ground General Purpose Header Heatsink Integrated Circuit Impedance Inductor Insulator Isolator Liquid Crystal Display Light Emitting Diode Lockwasher Low Speed Machine Metalized Paper Metalized Polycarbonate Module Metal Oxide Semiconductor Microprocessor Unit Mounting Mutliplexer Negative Channel Metal Oxide Semiconductor Oscillator Printed Circuit Board Plastic Panel Programmed Random Access Memory Rectifier Register Resistor 5 2 Table 5 3 Description of Abbreviations continued RGLTR REGULATOR ROM Read Only Memory SCR Screw SHLD Shoulder STDF Standoff TAN Tantalum TBAX Tube Axial VAR Variable VLTG REG Voltage Regulator WASH Washer WW Wire Would XFMR Transformer XSTR Transistor ZNR Zener Table 5 4 Federal Manufacturer Codes Code Manufacturer 01121 Allen Bradley Company Mlwaukee WI 16299 Corning Glass Works Raleigh NC 07263 Fairchild Semiconductor Corp Hicksville NY 28480 Agilent Technologies Palo Alto CA 80795 ITT New York NY 81483 International Rectifier Los Angeles CA 19701 Mepco Electro Corp Mineral Wells TX 04713 Motorola Semiconductor products Phoenix AZ 27014 National Semiconductor Corp Santa Clara CA 17896 Siliconxs Santa Clara CA 56289 Sprague Electric Company North Adams MA 01281 TRW Inc Philadelphia
188. matic diagrams and component location diagrams for the power supply 6 2 FUNCTIONAL SCHEMATIC DIAGRAMS The power supply circuits are shown on Figure 6 1 through 6 4 The schematics consists of one or more foldout sheets that illustrate the circuits functionally Figure 6 1 shows the ac power input and distribution for all models Power transformer connections and cable assembly part numbers for each model are included on pages 6 2 and 6 3 Figure 6 2 illustrates the circuits on the GPIB board This board is identical in all models Figures 6 3 and 6 4 illustrate the circuits on the 25W and 50W output boards The configuration for each model is as follows esa sow 2a sow 2a NU NU Figure 6 3 Sheets 1 through 5 show the following circuits and cover all output board types Differences between the types are indicated on the schematic Sheet 1 Secondary interface circuits Sheet 2 Bias Turn on and Overvoltage circuits Sheet 3 Control circuit FET downprogrammer Bleed and Sense Protect circuits Sheet 4 Power Mesh circuits Sheet 5 Ranging and Readback amplifiers Figure 6 4 Sheets 1 through 5 are similar to Figure 6 3 and cover all output board types Differences between the types are indicated on the schematic 6 3 COMPONENT LOCATION ILLUSTRATIONS 6 4 The component location diagrams show the physical location of parts mounted on each assembly Schematic Notes For Figure 6 1 Fuse F1 is 8A f
189. n a higher sink current limit about 2 2A R476 provides a small amount of positive feedback hysteresis to prevent jitter at the switch point 2 49 FET Downprogrammer When the output voltage drops below approximately 4V approximately 2 volts for the 50W outputs the Down Programming circuit comes on current sinking characteristics are shown in Figure 2 8 The FET Downprogrammer circuit part of U351A Q342 R456 is connected across the output Divider R464 R462 senses when the output falls below 4 Volts approximately 2V for the 50W outputs This turns on U351A and FET Q342 and connects R457 across the output to aid downprogramming Notice in Figure 2 8 on the 25W 5A graph the 15 ohm slope approximate 11 ohms for the 50W 2S outputs is due to the resistor R457 in series with FET Q342 and the 0 01 Amps at VOUT equals zero volts represents the bleed current in Q341 2 50 Overvoltage Protection Circuits These circuits generate the OV GATE signal which fires the SCR in the power module and shuts down the output Figure 2 9 is a simplified schematic of the overvoltage protection circuits which are comprised mainly of a fixed overvoltage sensing circuit U354 and divider R357 R359 that compares the OV DAC signal to the output voltage signal processor U327 diodes CR356 CR360 and pulse transformer T301 that couples CR356 CR360 and pulse transformer T301 that couples the remote trip signals that are sent received vi
190. next instruction so the microprocessor goes to the next highest address Therefore the address bus looks like a 16 bit counter that continuously rolls over and starts at zero The contents of each address appear sequentially on the data bus other side of the break In addition for all signature analysis tests jumper W201 must be moved from the NORM RUN position to the SIG ANALYSIS position see paragraph 4 23 2 13 Address Bus and Address Decoder microprocessor has 16 address lines A0 A15 allowing it to address 65 536 locations The address decoder U208 allows each addressable circuit to look at a shorter address The chip select signals 50 58 are decoded from the higher order address lines A12 A15 When a data buffer s CS is decoded it places its data on the data bus lines When a data latch s CS is decoded the output of each latch will be set to the logic state that is present on the associated data bus line If the chip select for the RAM random access memory ROM read only memory or talker listener chip is decoded the selected circuit will decode the lower order address bits supplied to it on the address bus 2 14 Memory ROM and RAM The system microcomputer contains both ROM U206 and RAM U207 devices The 32KK non volatile ROM contains the operating program and parameters The 2 K static RAM stores variables voltage to be programmed output current readback etc A third memory chip shown in the outp
191. nless ionized k Keep the work area free of non conductive objects such as Styrofoam type cups polystyrenefoam polyethylene bags and plastic wrappers Non conductive devices that are necessary in the area can be kept from building up a static charge by spraying them with an anti static chemical Agilent Part No 8500 3397 l Do not allow long hair to come in contact with static sensitive assemblies 4 3 REMOVAL AND REPLACEMENT The major assemblies within the power supply illustrated in Figure 4 1 The major differences between the models are the quantity and type of output boards they contain Figure 4 1 shows the output configuration for each model Component location diagrams and functional schematics for the individual assemblies are given in Section VI Replaceable electrical and mechanical parts for all models are listed in Section V The following paragraphs provide instructions for removing certain assemblies and components for which the procedure may not be obvious upon inspection Replacement procedures are essentially the same as the corresponding removal procedure except that they are performed in the reverse order 4 2 To avoid the possibility of personal injury remove the power supply from operation before removing the covers Turn off ac power and disconnect the line cord GPIB cable loads and remote sense leads before attempting any repair or replacement Most of the attaching hardware is metric Use of oth
192. nnect the output to be tested as shown in Figure 3 7 200000 ey Agilent 1401 0219 OR 1901 1087 3 AMP SILICON DIODE Figure 3 7 Down Programming Speed Test Setup Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel First program the selected output to zero volts by sending the string VSET lt ch gt 0 Using Channel A on the oscilloscope set the volts division switch to 10 V div dc coupled and position the trace on the bottom horizontal line Using Channel B on the oscilloscope set the volts division switch to 50 mV div dc coupled and position the trace on the bottom horizontal line Program the output voltage in a loop which alternately programs the output voltage between 0 and 50 volts by running the program listed below 10 OUTPUT 705 ISET ch lt 0 515 25W or 1 03 50W gt 20 OUTPUT 705 VSET lt ch gt 0 30 WAIT 0 05 40 OUTPUT 705 VSET ch 50 50 WAIT 0 05 60 GOTO 20 70 END NOTE The tested output s CV annnciator should remain on at all times while the test is in progress Observe Channel A on the oscilloscope and adjust for a stationary waveform by using Channel A as the trigger source set to trigger on a negative edge Be sure to trigger as lose as possible to the time when the output voltage just begins to fall 18 5V On Channel A observe the output voltage transition from the High Range Full Scale Voltage to the scope s
193. nt Part Description Mfg Mfg No Code Part No C369 0160 4833 CAPACITOR FXD 022uF 10 100VDC CER 16299 C370 0180 0393 CAPACITOR FXD 39uF 10 10VDC TA 56289 150D396X9010B2 C371 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C372 0160 4830 CAPACITOR FXD 2200PF 10 100VDC CER 16299 C373 74 NOT USED C375 76 0180 3804 CAPACITOR FXD 47uF 20 35VDC TA 56289 C377 80 NOT USED C381 0160 4835 CAPACITOR FXD 1 uF 10 50VDC CER 16299 C382 NOT USED C383 84 0160 4791 CAPACITOR FXD 10PF 5 100VDC CER 16299 C385 0160 4812 CAPACITOR FXD 220PF 5 100VDC CER 16299 C386 0160 4820 CAPACITOR FXD 1800PF 5 100VDC CER 16299 C387 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C388 0160 4801 CAPACITOR FXD 100PF 5 100VDC CER 16299 C389 0160 5098 CAPACITOR FXD 22uF 10 50VDC CER 16299 CAC05X7R224J050A C390 NOT USED C391 0160 4812 CAPACITOR FXD 220PF 5 100VDC CER 16299 C392 0160 5166 CAPACITOR FXD 015uF 20 100VDC CER 16299 C393 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C394 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C395 0160 5166 CAPACITOR FXD 015uF 20 100VDC CER 16299 C396 0160 4832 CAPACITOR FXD 01uF 10 100VDC CER 16299 C397 0160 5166 CAPACITOR FXD 015uF 20 100VDC CER 16299 C398 0160 5409 CAPACITOR FXD 3000PF 5 50VDC CER 16299 C399 0160 4787 CAPACITOR FXD 22PF 5 100VDC CER 0 30 04222 C400 0160 4830 CAPACITOR FXD 2200PF 10 100VDC CER 16299 C401 0160 4801 CAPACITOR FXD 100PF 5 100VDC
194. o conduct more and raise the output If the output exceeds the programmed value the DRIVE signal will divert current through Q335 and U348 of the base drive circuit and away from the BASE DRIVE power module input causing the series regulators to conduct less thereby reducing the output The voltage control VV circuit and the current control CL circuit is described in paragraphs 2 46 and 2 47 respectively When the output is operating in negative current limit the CL signal controls the base drive circuit via diode CR354 so that the DRIVE signal controls the conduction of the current sink transistors in the power module The negative current limit circuit which generates the CL signal is described in paragraph 2 48 The maximum Base Drive is reached when the drop across R428 reaches 6 volts turning on part of U348 which limits the base drive to Q335 2 46 Voltage Control Circuit When the output is operating in the constant voltage mode this circuit generates the CV control and CV LOOP signals The CV control signal is applied through OR gate diode CR351 to control the base drive circuit in order to regulate the output voltage The CV NEGATIVE CURRENT LIMIT CIRCUIT Figure 2 6 Voltage and Current Control Circuits Simplified Schematic Diagram 2 13 LOOP signal is sent back to the secondary interface circuit to indicate that the output is in the constant voltage mode of operation The voltage
195. ogrammed a programmed message or an error message The annunciators provide operating and status information The microprocessor uses the real time clock to determine when update refresh the display Data bus line D0 D2 are fed to the 3 to 8 line keyboard decoder U211 The microprocessor successively drives each of the eight open collector outputs of the decoder and monitors the four readback lines from the keyboard to determine which key was pressed The readback lines are held high until a depressed key pulls the line low 2 22 Data Buffers These 3 state buffers place the keyboard readback data on data bus lines D4 D7 when chip select 54 is decoded As stated above the microprocessor will use this information to determine which key was pressed In addition buffers provide the following data on bus lines D0 D3 when CS4 is decoded DO A logic 1 Jumper W201 is not installed in the Skip Self Test position tells the microprocessor to perform the self test at power on or a logic 0 Jumper W201 is installed in the Skip Self Test position tells the microprocessor not to perform self test at power on A logic 1 Jumper W201 is not installed in the Cal Lockout position tells the microprocessor to respond to calibration commands D1 or a logic 0 Jumper W201 is installed in the Cal Lockout position tells the microprocessor to ignore calibration commands This jumper provides security against unauthorized calibr
196. ooting tede te ate etg E JU Sa devas 4 29 Output Board Waveform During Self Exercise Routine HH eene 4 35 DAC Amplifier Circuit Troubleshooting ene e nee e ene nene eene nes 4 36 Overvoltage Troubleshooting oerte e eh ed vide Sa RE e san daa eo 4 37 Output Held Low Troubleshooting ode IIo rotat era ged Mow 4 39 Output Held High Troubleshooting tete tk teret e tester ee Pene re hause io Data ve pesa 4 42 OV Circuit Will Not Trip Troubleshooting sss HH mH hee eene e ehe nene nens 4 43 Signal Processor U327 Overvoltage Circuit Simplified Schematic 4 46 Signal processor 0327 Power On Start Up Circuit Simplified Schematic r A 4 46 Signal processor U327 Status Monitor Circuit Simplified 4 52 Status Problems Tro ubleshoottng geese mta Age 4 53 Power Distribution 5 6 3 GPIB Board Component Location ee nennen aaa aaa ne hene 6 5 GPIB Board Schematic Diagratm irissen iie eicit tt dde i RR Re PE ss usa 6 6 Output 1 amp 2 Board Componen
197. operly after turn on OV fires when output is loaded or during loading or unloading transients OV will not reset Output voltage programming speed out of specification See paragraph 3 15 for proper noise measurement technique Check dress of GPIB board cabling Check GPIB board and output board for loose ground screws Check for sense lead pick up see paragraph 4 12 in the Operating Manual Check for ripple on bias voltages or VREF voltages Check for about 2 5 V to 3 5 V on power module pins 5 to 8 when output voltage is programmed to full scale Check stable operating area with capacitive and inductive loads as given in Figures 1 4 through 1 6 of the Operating Manual Check output capacitors C416 and C417 Check compensation components tied to R420 for appropriate loop CV or CC Check power module compensation components between U338 pins 2 and 5 and capacitor s between pin s 5 and common Check for an open FET Q339 Check if board is in the self exercise mode see paragraph 4 28 Check that the sense leads are connected properly Regulation can be affected by load lead drop when remote sensing See paragraph 4 11 in the Operating Manual Check U352 U372 U374 U377 and U347 Check for oscillations on the output see remedy for the trouble symptom above Check for over 30 mV on R405 to confirm a leaky transistor P O U340B Check for leaky C390 C391 C393 Check guard amplifiers U373 U374 U375 and 10 mV clamp U3
198. or 100 120 Vac input or 4A for 220 240 Vac input Before connecting the supply to the power source check that the position of voltage line voltage source 100 120 220 or 240 Vac See Section Il in the Operating Manual Agilent P N 06626 90001 for details The reference designators W1 W2 etc for the cable assemblies are for schematic reference only Use the Agilent part number to physically identify cables in the supply Each cable is marked cable is marked with the appropriate Agilent Part No The illustration below shows the transformer T1 terminal designations The illustrations on pages 6 2 and 6 3 show the transformer T1 connections and cable part numbers for each model The line module connections are shown below MODEL Agilent 6626A AND Agilent 6629A TRANSFORMER 1 CONNECTIONS REAR VIEW TOP VIEW WHT VIO YEL RED BRN P O W12 P70 W12 P70 HIS BLK BLK BLK YEL GRN RED BUC ORY WHT VIO YEL RED BRN Wia P 0 HIS BOTTOM VIEH FOR CABLE PART NUMBERS REFER TO CHASSIS CABLE LISTING IN TABLE 5 5 MODEL Agilent 6625A AND Agilent 6628 TRANSFORMER T1 CONNECTIONS REAR VIEW WHTZYEL WHT VIO TOP VIEW WS 2 25 WHT BL WH ORN BLU 0 W12 LI EFL WH BL WH ORN BLU Wit P 0 W12 BOTTOM VIEW COO OP FOR CABLE PART NUMBERS REFER TO CHASSIS CABLE LISTING IN TABLE 5 5 BRN RED YEL VIO WHT P O LINE MODULE _ FOR AGILENT 66254 662
199. period of time to complete each test If failures are encountered or out of specification test results are observed refer to the Troubleshooting Procedures in Section IV in this manual The troubleshooting procedures will determine if repair and or calibration is required Calibration procedures are provided in Appendix A of the Operating Manual NOTE For mechanical reasons there are two different assemblies for the 50W 2A output boards When ordering replacement output boards determine the appropriate assembly number from Chassis Boards section of Table 5 5 Note that the replaceable parts on both 50W 2A assemblies are the same see Tale 5 7 3 2 TEST EQUIPMENT REQUIRED Table 3 1 lists the equipment required to perform the tests in this section The tests are performed by sending commands to and receiving data from the supply under test via the GP IB An Agilent Series 200 or 300 computer is used as the GP IB controller Tests that do not verify readback via the GPIB can also be performed manually from the supply s front panel and consequently do not require use of a controller 3 1 CAUTION The tests should only be performed by qualified personnel During the performance of these tests the output of the supply being tested may voltage levels above safe levels 3 3 OPERATION VERIFICATION TESTS To assure that all outputs of your supply are performing properly without testing all specified parameters perform th
200. planation and Remedy CAL LOCK 18 Calibration was attempted with jumper W201 installed in the CAL LOCKOUT position of connector P201 on the GPIB board see Figure 4 2 Install W201 in the NORM RUN position and recalibrate if desired CAUTION If W207 has been installed in the CAL LOCKOUT position of connector P201 on the GPIB board see Figure 4 2 and any calibration commands are sent to the power supply an error will occur The CAL LOCK message would be displayed if the error was gueried However second calibration command was sent to the power supply an error will again be generated and the write over the previous CAL LOCK error The message CAL ERROR will be dis played when the ERR key is depressed Error codes that can be sent back over the GPIB in re sponse to TEST TEST initiates a lim ited self test of the supply There are no messages on the front panel in response to the TEST query Onl the applicable error code is sent back No errors were detected The timer on the GPIB board failed Microprocessor U201 or real time clock U208 could be defective Perform the GPIB troubleshooting procedures see paragraph 4 18 The RAM U207 on the GPIB board failed self test see paragrph 4 18 The ROM U206 on the GPIB board failed self test see paragraph 4 18 4 18 GPIB BOARD AND FRONT PANEL 4 20 Post Repair Calibration TROUBLESHO
201. rcuitry associated with that one input is probably VMUX Response 1 2179 VM reads 009 defective see Figure 6 3 VMUX Response 2 2283 VM reads 0 VMUX Response 3 2179 VM reads 6 548 4 30 Understanding and Troubleshooting the VMUX Response 4 2179 VM reads 196 Signal processor U327 VMUX Response 5 2179 VM reads 949 VMUX Response 6 2179 VM reads 6 705 This custom IC processes both analog and digital signals to VMUX Response 7 2179 VM reads 9 404 interface the microcomputer U312 with the power mesh VMUX Response 8 2179 VM reads 9 419 and control circuits The signal processor circuits can be VMUX Response 9 2179 VM reads 13 336 functionally divided into three areas overvoltage and driver VMUX Response 10 2179 VM reads 6 548 power on start up and status monitor circuits A general VMUX Response 11 2179 VM reads 3 98 description of this IC is provided in paragraph 2 32 The VMUX Response 12 2179 VM reads 13 844 following information will help you troubleshoot the three VMUX Response 13 2179 VM reads 5 171 signal processor functions VMUX Response 14 2179 VM reads 13 64 VMUX Response 15 2179 VM reads 0 Proper operation of the IC can be verified by measuring the VMUX Response 16 2179 VM reads 009 pin voltages and using Table 4 17 which lists the voltage VMUX Response 17 2179 VM reads 0 levels and defines the low and high states This information VMUX Response 18 2179 VM read
202. rcuits the power control analog and digital circuits and power output analog circuits are described These descriptions are intended as an aid in troubleshooting Verification Section III contains test procedures that check the operation of the supply to ensure that it meets the specifications given in Section I of the Operating manual Troubleshooting Section IV contains board level troubleshooting procedures to isolate a malfunction to a defective board GPIB or output board or assembly front panel power transformer or cable assembly Additional troubleshooting procedures are provided to isolate the fault to a defective component on the board Board and assembly level removal and replacement procedures are also given in this section NOTE Calibration is generally required after a repair is made Software calibration procedures are given in Appendix A of the Operating Manual After calibration is completed perform the applicable test s given in Section of this manual to ensure that the supply meets all specifications 1 1 Replaceable Parts Section V provides a listing of replaceable parts for all electronic components and mechanical assemblies Circuit Diagrams Section VI contains functional schematics and component location diagrams The names that appear on the functional schematics also appear on the block diagrams in Section II Thus the descriptions in Section II can be correlated with both the block diagr
203. rcuits on the GPIB board as well as the keypad and display circuit boards on the front panel The tests should be performed in sequence i e Test No 1 No 2 etc Note that the signatures taken for the ROM S A Test No 2 Table 4 7 apply only to firmware revision A 00 date 2839 see paragraph 4 24 The general test setup for S A tests is given in paragraph 4 23 The following general notes apply to signature analysis of the GPIB board 1 certain to use the correct test setup 2 Note the signatures for Vcc 5V and ground on the IC being examined If an incorrect signature is the same as that of Vcc or ground that point is probably shorted to Vcc or ground 3 If two pins have identical signatures they are probably shorted together If two signatures are similar it is only a concidence 4 If a signature is incorrect at an input pin but is correct at its source output of the previous IC check for printed circuit and soldering problems 5 An incorrect signature at an output could be caused by a faulty component producing that output It can also be caused by an input short circuit in another component on the board 4 12 4 23 Test Setup for S A Figure 4 7 shows the general test setup for the signature analysis tests given in Tables 4 6 through 4 13 Note that jumper pack W202 can be installed in either of two positions as shown in Figure 4 7 The following is a general description of the test setup Speci
204. re 4 2 with jumper position that are used for normal operation of the power supply or troubleshooting The following discussion describes the function of each of four jumper positions 5 V NORM RUN This jumper position is used as the normal running position The two pins on P201 that W201 connects in this position are both tied to the GP IB board 5 V bias supply The jumper is simply stored in this position when not used in one of the other positions CAL LOCKOUT This position is an alternate to the NORM RUN position and is used to ensure against accidental calibration of the power supply With W201 in blank display blank display 8291 FAILED TIMER FAILED CV DAC CH ch CL DAC CH ch OV DAC CH ch FUSE CH ch HDW ERR CH ch HDW ERR CH ch test skipped test skipped test skipped test skipped test skipped test skipped test skipped test skipped test performed test performed this position error number 18 CAL LOCKED is generated if an attempt is made to turn on the mode see Appendix calibration in the Operating Manual This position is used to perform signature analysis on the GPIB board for troubleshooting the GPIB board see para 4 23 This position causes the power supply to skip the power on self tests described in paragraph 4 15 This position allows the GPIB board to attempt to power on all output boards in the supply even if one or more output would would not have pa
205. roubleshooting Analog Multiplexer reete 4 29 m oae eet eee 4 7 Front eds 4 11 4 11 Miscellaneous Symptoms sse 4 31 rege 4 28 Signal Processor 4 30 Agilent Sales and Support Office For more information about Agilent Technologies test and measurement products applications services and for a current sales office listing visit our web site http www agilent com find tmdir You can also contact one of the following centers and ask for a test and measurement sales representative United States Agilent Technologies Test and Measurement Call Center P O Box 4026 Englewood CO 80155 4026 tel 1 800 452 4844 Canada Agilent Technologies Canada Inc 5150 Spectrum Way Mississauga Ontario L4W 5G1 tel 1 877 894 4414 Europe Agilent Technologies Test amp Measurement European Marketing Organisation P O Box 999 1180 AZ Amstelveen The Netherlands tel 31 20 547 9999 Japan Agilent Technologies Japan Ltd Measurement Assistance Center 9 1 Takakura Cho Hachioji Shi Tokyo 192 8510 Japan tel 81 426 56 7832 fax 81 426 56 7840 Technical data is subject to change Latin America Agilent Technologies Latin American Region Headquarters 5200 Blue Lagoon Drive Suite 950 Miami Florida 33126 U S A tel 305 267 4245 fax 305 267 4286 Australia New Zealand Agi
206. rough the Data Buffers U216 and to the output of Data Latches U213 in the Output Boards Inteface Circuit Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer Edge P201 PIN Input Setting Connection START H STOP 12 CLOCK 16 GND 4 Measurements Use the data probe to take signatures for each circuit at the input and output pins listed below Circuit Input Signature Output Signature 5 P201 1 3U9F U216 2 U216 4 SYSTEM U216 6 DATA BUFFERS U216 8 U216 U216 11 Data Bus Lines U216 13 U216 15 U216 17 U213 3 U213 2 U213 4 U213 5 OUTPUT BOARDS U213 7 U213 6 INTERFACE U213 8 U213 9 DATA LATCHES U213 13 U213 12 U213 U213 14 U213 15 U213 17 U213 16 U213 18 U213 19 4 20 Table 4 9 Board S A Test 4 Description This test checks Data Buffers U212 the Output Boards Interface Circuit which send data back to the System Microcomputer from the Output Boards Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer P201 PIN Input i Connection START 11 STOP 12 CLOCK 17 GND 4 Measurements Use the data probe to take signatures for each circuit at the input and output pins listed below Circuit Input Signature Output Signature 9 P201 1 3U9F U212 2 U212 3 U212 4 U21
207. rts List Design Agilent Part Description Mfg Mfg No Code Part No C300 0160 4833 CAPACITOR FXD 022uF 10 100VDC CER 16299 C301 0180 3801 CAPACITOR FXD 1800uF 30 10 63VDC AL 56289 C302 0180 3799 CAPACITOR FXD 2700uF 30 10 50VDC AL 56289 C303 04 0160 4835 CAPACITOR FXD 14F 10 50VDC CER 16299 C305 0180 0291 CAPACITOR FXD 1uF 10 35VDC TA 56289 150D105X9035A2 C306 0180 0100 CAPACITOR FXD 4 74F 10 35VDC 56289 150D475X903582 C307 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C309 0180 0291 CAPACITOR FXD 1uF 10 35VDC TA 56289 150D105X9035A2 C310 0180 0100 CAPACITOR FXD 4 7uF 10 35VDC 56289 1500475 9035 2 C311 14 0180 0291 CAPACITOR FXD 1uF 10 35VDC TA 56289 150D105X9035A2 C315 0160 4281 CAPACITOR FXD 2200PF 20 250VAC RMS C0633 PME271Y422 C316 19 NOT USED C320 0160 4800 CAPACITOR FXD 120PF 5 100VDC CER 16299 C321 22 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C323 0160 4800 CAPACITOR FXD 120PF 5 100VDC CER 16299 C324 0160 4787 CAPACITOR FXD 22PF 5 100VDC CER 16299 C325 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C326 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C327 0160 4801 CAPACITOR FXD 100PF 5 100VDC CER 16299 C328 0160 4807 CAPACITOR FXD 33PF 5 100VDC CER 16299 C329 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C330 0160 4801 CAPACITOR FXD 100PF 5 100VDC CER 16299 C331 32 NOT USED C333 34 0160 4835 CAPACITOR FXD 1uF 10 50VDC CER 16299 C335 NOT USED C336 0160 48
208. rts List Continued Design Agilent Part Description Mfg Mfg No Code Part No R516 604 NOT USED R605 0757 0199 RESISTOR 21 5K 1 125W TF 24546 CT4 1 8 TO 2152 F R606 09 NOT USED R610 11 0757 0199 RESISTOR 21 5K 1 125W 24546 CT4 1 8 TO 2152 F R612 19 NOT USED R620 0757 0442 RESISTOR 10K 1 125W TF 24546 CT4 1 8 TO 1002 F R621 0683 1825 RESISTOR 1 8K 5 25W CF 01121 CB1825 R622 23 NOT USED R624 0698 0087 RESISTOR 316 1 25W 24546 NA5 1 4 TO 3160 F R625 NOT USED R626 0757 0465 RESISTOR 100K 196 125W TF 24546 CT4 1 8 TO 1003 F R627 0757 0442 RESISTOR 10K 196 125W TF 24546 CT4 1 8 TO 1002 F R628 0757 0465 RESISTOR 100K 196 125W TF 24546 CT4 1 8 TO 1003 F R629 0757 0442 RESISTOR 10K 196 125W TF 24546 CT4 1 8 TO 1002 F R630 0757 0199 RESISTOR 21 5K 196 125W TF 24546 CT4 1 8 TO 2152 F R631 0698 4435 RESISTOR 2 49K 196 125W TF 24546 CT4 1 8 TO 2491 F R632 33 0757 0465 RESISTOR 100K 196 125W TF 24546 CT4 1 8 TO 1003 F R634 0757 0200 RESISTOR 5 62K 196 125W TF 24546 CT4 1 8 TO 5621 F R635 0757 0465 RESISTOR 100K 196 125W TF 24546 CT4 1 8 TO 1003 F R636 46 NOT USED R647 0683 6855 RESISTOR 6 8M 5 25W CC 01121 CB6855 R648 58 NOT USED R660 0757 0401 RESISTOR 100 196 125W TF 24546 CT4 1 8 TO 101 F R661 62 0757 0469 RESISTOR 150K 196 125W TF 24546 CT4 1 8 TO 1503 F R663 0757 0401 RESISTOR 100 196 125W TF 24546 CT4 1 8 TO 101 F R664 0757 0438 RESISTOR 5 11K 196 125W TF 24546 CT4 1
209. rve the output voltage transition from the scope s bottom horizontal line to 50 volts Look for a smooth exponential waveform with no by insuring that the output voltage rises to about 31 5 volts 6376 in less than SUPPLY 750 usec Refer to the Channel A waveform shown in Figure 3 10 ps Now observe Channel B on the oscilloscope while Figure 3 9 CV UP Programming Speed Test Setup SERIES Zr a sev BUCKING maintaining the trigger on Channel A as in step h Note the series supply bucks out the Full Scale Output Voltage and that the waveform is clamped at approzimately 0 6 V and rises to the top horizontal line when the output voltage is at full Agilent 1901 0219 OR 1981 1287 3 AMP SILICON DIODE 3 13 Scale The diodes see Figure 3 9 prevent gross b overload of Channel B which is set at 50 mV division allowing examination of the tail of the exponential waveform The output voltage should be within 50 mV of its final settling value on the top horizontal line is less than 6 msec Do not turn on the supply This test is performed with the ac power turned off To avoid possible damage to the output under test the external supply should be current limited to less than 1 amp n Set the external power supply to 50 V d Slowly increase the voltage of the external supply until the overvoltage circuit in the supply under test trips This is indicated by a sudden drop in the voltage of the e
210. s levels scilloscope p Load Resistor Resistor 0 1500hms 100W ssid 0 1500hms 100W ssid 100 W ment Required for Troubleshooting GPIB Controller Communicate with the supply via the GPIB Agilent Series 200 or 300 Controller Signature Analyzer Test most of the circuits on the GPIB board Agilent 5005A 30V 3A Check current sink Logic Probe Check bus lines on output board Agilent 545A Check clock signal waveforms and signal levels on GPIB and output boards Frequency Counter Check operation of the RAM and ROM on the Part of Agilent GPIB board 5005A or use an cmt 5384A Be sure to remove the AC line cord from the unit before attempting to work on the AC line module To remove the AC line module first disconnect all of the wires from it including the RFI capacitor Then use a screwdriver inside the unit to press the mounting clip on one side of the line module and push from inside the unit that side of the module slightly away from the chassis Finally use the screwdriver again to press on the mounting clip on the other side of the module and push that side out The module can be replaced simply by sliding it straight back into the mounting hole until the mounting clips spring into position securing the module The wires can be replaced according to the AC connections shown in Figure 6 1 4 12 TEST EQUIPMENT REQUIRED Table 4 1 lists the test equipment required to troubleshoot the power supply Recommen
211. s 949 in used in conjunction with the pin description paragraph 4 31 and simplified schematics to troubleshoot the signal Exceed 10 V limit because value exceeds low range processor s overvoltage Figure 4 15 power on start up limit Figure 4 16 and status monitor circuits Figure 4 17 Positive voltage due to op amp saturation Additional troubleshooting information for the status Note that there is a 200 mV offset in V which allows monitor circuit is given in paragraph 4 22 and Figure 4 18 for negative voltage 4 31 Signal Processor U327 Pin Function Description The Table 4 16 shows the 18 input voltage values as well as The signal processor s circuits are shown on the functional the VMUX response for a typical calibrated 25 WATT schematic of Figure 6 3 sheet 1 and on the block diagram of output 300 mA Load whose voltage and current has been Figure 2 4 The 28 Signal processor pins are described as programmed to the Low voltage range and high current follow The output is set to 5 volts and 0 5 Amps 5 V pin 1 The 5 V bias voltage can range from 4 72 V to If all of the inputs read back by the VMUX command are 5 23 V incorrect the analog multiplexer U323 and or the readback Table 4 16 U368 MEASUREMENTS Measured Parameter U323 Approx FUNCTION Switches are neg true 0 Closed INPUT Vm 1 1 2 FUSE 2 0 0 75 to
212. s about a diode drop between these two input pins The current sources drive the series regulator into conduction via the BASE DRIVE input The DRIVE input from the base drive circuit see paragraph 2 42 controls the amount of BASE DRIVE current that drives the series regulators in order to maintain a regulated output Any BASE DRIVE current from the current source that is not required by the series pass transistor to regulate the output is drawn away by the control circuit through the DRIVE input via Q335 A level of current through Q335 that exceeds the BASE DRIVE current can turn on the power module current sink transistors to sink output current up to the negative current limit value SCR Overvoltage Circuit The power module has an internal SCR whose gate input is capacitively coupled to the OV GATE pin The OV GATE signal can fire the SCR for a number of reasons which are described later under the Overvoltage Protection Circuit paragraph In addition to shorting the output the fired SCR will cause the OV SENSE signal to go low signaling the microcomputer to program the output to zero The output will remain shorted and programmed to zero until the circuit is reset The SCR circuit is reset when the POV DISABLE signal OVRST command is received by the OV reset circuit Q320 The condition that caused the overvoltage must be removed in order for the circuit to remain reset If the condition is not removed the OV GATE si
213. signal is compared with the output voltage exceeds the programmed setpoint see paragraph 2 44 The signals is also sent to the analog multiplexer so that it can be measured during power on self test 2 31 Readback Amplifier and Analog Multiplexer The analog multiplexer U323 selects one of eight inputs value of these inputs are from 0 to 10 Volts to be applied to the readback signal comparator U324 for the A to D converter The selected signal is determined by address lines 0 2 which are received from the microcomputer The analog inputs to the multiplexer indicate the following COM hardwired to common to reduce noise when no signals are being sampled FUSE output board s return fuse status read back during power on self test VFS Readback amp output U315A V IMUX Range amp output U315C CV DAC voltage DAC output CCDAC current DAC output OV DAC overvoltage DAC output U315C can be configured as an inverting or non inverting amplifier Swiches U365 determine it s configuration as well as the input to amplify U366 is use to determine the gain of the amplifier U315B is used as a buffer For current readback inputs from the 4 terminal shunt resistor 408 are select via U365 For voltage readback low range U366 D is used as the input to U315C 2 32 Readback DAC and Signal Comparator The readback DAC U321 amplifier U362 readback signal comparator U324 and analog multiplexer
214. ssed self test Egrci se re wh en usi ng SKP SELF TEST on a unit with ou tput bo ards t hat are kown to fail se If test si nce th eoutp ut may op erate bey ond its rated parameters The outp ut voltage may even reac h full sc ale voltage withou t be ing programmed SIG ANALYSIS SKIP SELF TEST 4 17 ERROR Codes and Messages Table 4 5 lists all of the error codes and messages that can occur when operating the supply Each code and the corresponding message if applicable are explained and a remedy or troubleshooting procedure is recommended This table is used in conjunction with Figure 4 5 and other troubleshooting flow charts provided in this section HIGH RAIL P382 F303 MED RAIL U338 LOOP F389 F308 536 3 2 403 Loran free LOOP CL LOOP 57 ASSEMBLY DWG 15 UNREG M Figure 4 4 Output Board 3 and 4 Fuse and Test Point Locations Table 4 4 Power On Self Test Error Messages Front Panel Display Message TIMER FAILED 8291 FAILED CV DAC CH ch CC DAC CH ch OV DAC CH ch FUSE CH ch HDW ERR CH ch Explanation Troubleshooting Procedure The timer on the GPIB board failed Microprocessor U201 or real time clock U209 could be defective Perform GPIB board troubleshooting procedures see paragraph 4 18 The GPIB talker listener U202 on the GPIB is probably defective Perform S A test No 5 Table 4 10 The voltage DA
215. st measures the change in output current within the first 30 minutes of a change in the line voltage or the load Place the supply to be tested in a temperature chamber or in a temperature controlled environment such as a standards room a Turn off the supply and connect the output to be tested as shown in Figure 3 3 with the DVM connected across the current monitoring resistor the load switch closed and the short switch opened Connect the supply to the ac power line through a variable voltage transformer and adjust it for the nominal value b Turn on the supply and select the output to be tested OUTPUT SELECT key on front panel c Program the current of the selected output to 500 mA for 25 Watt outputs or 2 Amps for 50 Watt outputs and the output voltage to 7 Volts d Adjust the load until the output enters the CC mode with the displayed output voltage slightly less than 7 volts The CC annuciator must be on e Adjust the transformer to 13 below the nominal voltage f Wait 30 minutes for the output to stabilize under these conditions and record the output current DVM reading 0 1 shunt resistance g Adjust the transformer to 6 above the nominal voltage h Wait 30 minutes and record the output current The difference in the readings taken in steps f and h should be less than 70LA 25W or 260 pA 50W i Close the short switch and immediately record the output current j Wait 30 minutes and again record the output
216. state of the POV DISABLE signal As shown in Figure 2 9 OV TRIP is the output of a wired OR gate and can be activated by either the SENSE PROTECT signal as described in paragraph 2 44 or by the REMOTE OV TRIP signal The REMOTE OV TRIP signal can be generated by the fixed OV sensing circuit or by a remote signal connected to the output s OV and OV terminals Fixed Overvoltage Sensing Circuit The fixed overvoltage sensing circuit U354 continually monitors the voltage across the VOLTS OUTPUT VOLTRGE VOLTS 1 8 Tout SINK AMPS TYPICAL DOWNPROGRAMMING CHARACTERISTICS Figure 2 8 Typical Downprogramming Characteristic Below 2 0 V 2 16 BELOW 2 VOLTS S W 2A output terminals Because it is biased by the voltage at the output terminals it can be activated and provide protection even when the supply is not connected to the ac power line The fixed overvoltage sensing circuit will activate when it senses a voltage that is approximately 120 of the maximum rated output voltage for the associated output If the output voltage exceeds this threshold the OV GATE signal is generated via diode CR358 and fires the SCR Note that the fixed overvoltage sensing circuit will also activate the OV DRIVE signal via diode CR359 REMOTE OV TRIP The OV DRIVE signal then transmits the overvoltage condition to the OV terminals via diode CR356 and transformer T301 as previously described As shown in F
217. switch opened b Turn on the supply and select the output to be tested OUTPUT SELECT switch on front panel c Program the current of the selected output to the High Range Full Scale Current value and the output voltage to 50 5 volts by sending the following strings ISET ch 0 5 VSET ch 16 NOTE This test must be performed with a resistive load only The use of an electronic load will invariably inject extra ripple and may cause the CC RMS noise to be out of specification d Adjust the load resistor to about 30 ohms so that the output voltage is close to 15 volts Check that the CC annunciator is on e Note that the reading on the rms voltmeter should be less than 5 mV equivalent to 0 1 mA RMS f Repeat this test steps a through e for each output in your supply 3 26 Performance Test Record of the performance test specifications for the power supply are listed in Tables 3 3 and or 3 4 Table 3 3 covers the 25 watt outputs Table 3 4 covers the 50 watt outputs 3 10 3 27 EXTENDED TESTS These tests are similar to the Performance Tests except they have a much longer duration are conducted with controlled temperature conditions or test supplemental characteristics 3 28 Output Drift The tests are divided into two parts short term and long term drift For all drift tests place the supply to be tested in a temperature chamber or in a temperature controlled environment such as a standards room 3
218. t _ nnne 6 7 Output 1 amp 2 Board Schematic 1 nne hen nennen nnne rne nn rennen nennen 68 Output 3 amp 4 Board Component Location 1 1 nhe nen ne rhe reser nennen cii 6 13 Output 3 amp 4 Board Schematic Diagram aaa aaa aaa aaa aaa aaa aaa 6 14 iil LIST TABLES Table Page 3 1 Test Equipment Required for Verification isses IAA 3 2 3 2 Low Range Voltage and Current Values ua aa cnet een OO Pe ea vies vane otoki 3 4 3 3 Performance Test Record for Agilent 6625A and 6628A 3 15 3 4 Performance Test Record for Agilent 6626A and 6629 9 3 16 4 1 Test Equipment Required for Troubleshooting 4 5 dea red bevel aout 4 6 4 30 Tests Performed Nos e 4 8 4 4 Power On Self Test Error Message sso teesi oo auo eV eee 4 9 4 5 ERROR Codes and Messages eono eE EEE ee siepe Pe Doe gate e So Odo SEE e Dd aqa DE obe askai PO aju 4 10 c b e e S 4 18 4 7 GPIB Board S A T
219. t board s mounted in the hinged upper chassis as well as those mounted in the lower main chassis Be sure to avoid any cable snag when opening the hinged chassis d Place the removed top cover assembly under the opened upper chassis for support Agilent 6626A Agilent 6629A Figure 4 1 Agilent 6625A 6626A 6628A and 6629A Multiple Output Power Supplies Assembly Locations 4 3 4 6 GPIB Board Removal Looking at the unit form the front the GPIB board is located on the right side with its components facing to the left Most of the components are accessible for test purposes without removing the board from the units However for easy access it is best to remove the board from the unit To remove the GPIB board proceed as follows a Disconnect all cables Note the routing of cables if they to be removed since their position may affect the supply s ripple performance b Remove two hex standoffs form rear which secure the GPIB connector to the chassis Retain the lock or flat washers for reassembly c Remove one ground screw from the top front of the GPIB board Retain lock or flat washers for reassembly d Slide board forward approximately 1 4 inch to disengage the keyed standoffs e Lift board out of chassis 4 7 Output Board Removal Model 6625A and 662 has two Output boards located in the main chassis and Model 6626A and 6629 have four Output boards two boards are mounted in the upper chassis assembly and
220. t eee setate tee edes epe cases a 3 6 Transient Response Waveforms E PE o M SE PO e gos oe Se EURO EE 3 7 Negative Current Limit CC Readback Accuracy 3 9 Down Programming Speed 3 12 CV Down Programming Speed Test Waveform 2 e eee 3 13 CV Up Programming Speed Test Setup uvas cene ee p ae tre cuales oversees i ae rede vee 3 13 CV Up Programming Test Waveform s eee eret eset aee e ea 3 14 Fixed OV Protection Test Setup tere ee rer MEE 3 14 OV External Trip Test Connection veces cei cce eer ot ete pe ses ees ine ed o A 3 14 Agilent 6625A 6626A 6628A and 6629A Multiple Output Supplies Assembly Locations 4 3 HP IB Board Fuse and Test Point Locations Hee ehe eee ene ee nnns 4 6 Output Board 1 and 2 Fuse and Test Point Locations 4 7 Output Board 3 and 4 Fuse and Test Point Locations 4 9 Initial Troubleshooting and Board Isolation HH Hee 4 19 HP IB Board and Front Panel Troubleshooting 4 15 Signature Analysis Test Setup 2220 ete e e aarete TA akg O PNA eer Ra en aa aa dey 4 17 Output Board Troublesh
221. t panel Test Setup Use the test setup described in paragraph 4 23 Connect jumper pack W202 in the NOP and set up the signature analyzer as shown below Signature Analyzer Edge P201 PIN Input Setting Connection START 11 STOP 12 CLOCK 18 GND 4 Measurements Use the data probe to take signatures for each key at the input and output pins listed below The appropriate key must be pressed and held while the singatures are measured at the specified pins The 5V signature for this test is 3U9F The signal path for each pressed key is given in Table 4 14 Figure 6 2 shows the keypad schematicaly SIGNATURES U214 OUTPUT PINS U214 INPUT PINS 5 7 11 13 15 3U9F 3U9F 3U9F 3U9F 3U9F 3C96 3096 3U9F 3U9F 3U9F 3U9F CP 3UIH RESET 3U9F VOLT t 3U9F VOLT 3U9F CURR 3788 CURR 3U9F OUTPUT SELECT OUTPUT SELECT VSET 3U9F 3U9F 3U9F 4 25 Table 4 13 GPIB Board S A Test 8 cont SIGNATURES U214 OUTPUT PINS U214 INPUT PINS 5 7 11 13 15 ISET 3U9F 3U9F 2UC5 OUTPUT ON OFF 3U9F 3H99 3U9F 3U9F 3P9P 3U9F 3U9F 3U9F 3H99 3U9F 3U9F 3P9P 3U9F 3U9F 1UU1 3U9F 3U9F 3U9F 3U9F 3U9F 3U9F 3U9F 3U9F 3U9F 3P9P 3U9F 3U9F 1001 3U9F 3U9F 3UHF 3U9F 3U9F 3U9F 3UHF 3U9F 3U9F 1UU1 309 3U9F 3U9F 3UHF 4 26 Table 4 14 Keypad Signal paths See Figure 6 2 Scan Lines Keyboard Readback Lines from Decoder connector pins to Data Buffer U211 pin U214 pin 2 and 14 8 and 14 6 an
222. ted as shown in Figure 3 3 with the DVM connected cross the current monitoring resistor the load switch closed and the short switch opened b Turn on the supply and select the output to be tested OUTPUT Select key on the front panel c Program the current of the selected output to 0 5 Amps 25W or 2 Amps 50W and the output voltage to 7 volts d Adjust the load until the output enters the CC mode with the displayed output voltage slightly less than 7 volts as read on the front panel display Check that the CC annunciator is on e Wait 30 minutes and record the output current DVM reading 0 1 Shunt resistance f Observe and record the output current reading periodically over an 8 hour period The difference between any two readings should be less than 70 A 25W or 260 LA 50W g Repeat steps a through f for each output in your supply 3 33 TEMPERATURE COEFFICIENT TC TESTS These tests check temperature coefficient specifications with the supply placed in a temperature controlled oven that provides an even temperature distribution The temperature is varied over the supply s operating range and changes in output voltage and current are measured The supply is left in the oven for 30 minutes to ensure stability Note that the test equipment e g current monitor resistor DVM load etc is located outside of the oven 3 34 Output Voltage and Readback Voltage TC a Turn off the supply and connect the output to be test
223. the 8 data lines and 8 control lines and the GPIB talker listener chip U202 GPIB 488 functions are implemented by the GPIB chip which handles data transfer between the microprocessor and the GPIB handshake protocol and talker listener addressing procedures The GPIB talker listener chip is connected to the data bus and appears as memory locations to the microprocessor The eight data lines DIO1 DIO8 of the GPIB are reserved for the transfer of data and other messages in a byte serial bit parallel manner Data and message transfer is asynchronous coordinated by the three handshake lines DAV NRFD and NDAC The power supply can be a talker or a listener on the GPIB The controller dictates the role of an GPIB device by setting the ATN attention line true and sending talk or listen addresses on the data lines DIO1 DIO8 The power supply s GPIB address is stored in the EEPROM electrically erasable programmable memory chip along with other system variables You can find out your supply s GPIB address by using the front panel ADDR key as described in the operating manual As shipped from the factory the power supply s address is set to 5 Any address from 0 through 30 is a valid address There are five GPIB control lines ATN IFC REN SRQ and EOI IEEE 488 When the controller sets the ATN line true all devices on the bus must listen to the addresses and universal commands placed on the bus When A
224. the DVM connected across the current monitoring resistor the load switch closed and the short switch opened Adjust the transformer to 13 below the nominal line voltage Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel Program the current of the selected output to the High Range Full Scale Current value and the output voltage to 50 5 volts by sending the following strings ISET lt ch gt lt 0 5 25W or 2 50W gt VSET lt ch gt lt 50 5 gt f Repeat the load for High Range Full Scale current and 50 volts indicated on the front panel display Check that the CC annunciator is on If it is not adjust the load so that the output voltage drops slightly g Record the output current reading DVM reading 10 h Adjust the transformer to 6 above the nominal line voltage i Record the output current reading again The difference in the current readings in steps g and I is the CC source effect and should not exceed the values listed below for the particular output being tested Output CC Source Effect 25W 5 A 50W 10 j Repeat this test steps a through I for each output in your supply 3 25 CC RMS Noise This test measures the rms noise in the output when operating in the constant current mode a Turn off the supply and connect the output to be tested as shown in Figure 3 3 with an rms voltmeter connected across the output the load switch closed and the short
225. ther regularly scheduled jobs The R W read write output from the microprocessor indicates the direction of flow on the data bus either to or from the microprocessor A low level R W signal indicates that the microprocessor is writing data onto the data bus A high level R W signal indicates that the microprocessor is reading data that was placed on the bus by the addressed circuit The microprocessor uses the address decoder circuit and the address bus to specify the data transfer locations Addresses are valid on the rising edge of the Q signal 2 11 Data Bus latches U217 and Buffers U216 The timing sequence of the microprocessor is such that the circuits providing data for the microprocessor are de selected address disappears before the microprocessor can read the data The data bus latches U217 latch the data to be read by the microprocessor The data is updated on every falling Q pulse Data put on the data bus by the microprocessor goes around the latches though buffers U216 2 12 Free Run and Signature Analysis Jumpers The data bus is connected to the microprocessor through a jumper pack W202 For some signature analysis tests of the microprocessor kernel microprocessor RAM ROM the data bus is broken by moving W202 from the NORMAL position to the NOP position see paragraph 4 23 This connects a NOP no operation code free run to the microprocessor data inputs The NOP code does not contain an address for the
226. to be tested as shown in Figure 3 4 b Turn on the supply and select the output to be tested OUTPUT SELECT key on the front panel c Program the selected output s voltage to 50 V and the current to 0 515 25W or 1 03 50W d With R2 disconnected connect R1 and ensure the output is 100 mA as indicate on the front panel display e Connect R2 and adjust the output to read 0 5 Amp 25W or 1Amp 50W on the front panel display Note that the CV annunciator should be on If itis not on readjust R2 until it is on UNLOADING TRANSIENT Figure 3 5 Transient Response Waveform f Set the oscilloscope to 50 mv div ac coupled 10 us div internal trigger normal and slope g Turn on the load switch to perform the transient response test Alternatively remove modulate an electronic load between 100 mA and 0 5 Amp 25W or 1 Amp 50W Note that if an electronic load is used the load s current rise time must be less than 25 usec to perform an adequate test If a load with longer rise time is used the transient response recovery time may appear to be out of specification h Adjust the oscilloscope trigger level for a stationary waveform as shown in Figure 3 5 and check that the loading transient is within 75 mV of its final value in less than 75 us i Change the oscilloscope settings to slope and repeat steps g and h for the unloading transient see Figure 3 5 j Repeat steps a through I for each output in your
227. tput impedance constant 2 44 Sense Protect Circuit This circuit P O U375 and P O U351 monitors the voltage from V to S and from S to V If either of these voltages exceeds 1 0 V the sense protect circuit will generate a signal which will fire the overvoltage protection circuits and shut down the output see paragraph 2 50 This circuit prevents the output voltage from being regulated at a value higher than the maximum value for which it was designed 2 45 Base Drive Circuit When activated ON OFF is at approximately 2 4 volts this circuit Q335 and U348 provides the DRIVE input to the series regulator and current sink transistors in the power module The DRIVE input determines how much drive current BASE DRIVE the power module will receive The DRIVE input is controlled by either the voltage control CV current control CL or negative current limit circuits CL 1 Figure 2 5 Output Board Power Mesh and Control Circuits Block Diagram 2 12 The or CL signal controls the base drive circuit via OR gate diodes CR351 or CR348 to generate the DRIVE signal in order to control the conduction of the series regulators in the power module and provide a regulated output If the output is less than the programmed value the DRIVE signal will allow more BASE DRIVE current causing the series regulators t
228. ts from a change in ac line voltage from the minimum to maximum value within the line voltage specifications a b Turn off the supply and connect the ac power line through a variable voltage transformer Connect the output to be tested as shown in Figure 3 3 with the DVM connected between the S and S terminals the Load switch closed and the Short switch opened Adjust the transformer to 13 below the nominal line voltage Turn on the supply and select et output to be tested OUTPUT SELECT key on the front panel Program the current and voltage of the selected output to the value below by sending the following strings ISET lt ch gt lt 0 515 25W or 1 03 50W gt VSET lt ch gt lt 50 gt Adjust the load for 0 5 A 25W or 1 A 50W as indicated on the front panel display The CV annunciator on the front panel must be on If it is not adjust the load down slightly Record the output voltage reading on the DVM Adjust the transformer to 6 above the nominal line voltage Record the output voltage reading on the DVM The difference between the DVM readings in steps g and i is the source effect voltage and should not exceed 0 5 mV Repeat steps b through I for each output in your supply Be sure to turn off supply before performing step b 3 15 CV Noise PARD Periodic and random deviations PARD in the output ripple and noise combine to produce a residual ac voltage superimposed on the dc output voltage CV PARD
229. two are mounted in the main chassis To remove an Output board proceed as follows NOTE Before you can remove output 3 located in the main chassis you must remove the GPIB board a Disconnect all cables Note the routing of cables if they must be removed since cable position may affect the output s ripple performance b Remove one ground screw located at rear of board near terminal block Retain the lock or flat washers for reassembly c Remove one ground screw located at extreme front of board Retain the lock or flat washers for reassembly d Remove two screws which hold the heat sink assembly to the chassis These must be removed completely e Slide the board slightly forward to disengage the keyed standoffs f Lift board out of chassis 4 8 DUSTCOVERS This instrument employs plastic covers to protect a number of components on each output board The covers provide a constant temperature environment for the sensitive components below them Before installing these covers be 4 4 sure to eliminate any static charge which may have accumulated on them Removing static charge can be accomplished using an ionized air source directed across the covers CAUTION After performing maintenance and before performing any calibration be sure to replace the plastic covers on the output boards s Failure to replace the cover s may allow thermal conditions to affect components in these areas This can result in incorrect
230. ure Pre Cal Post Test Performed by Date Humidity Output Accuracy DVM Reading 25W High Range 0 10 mV Low Range 0 1 5 mV 50W High Range 0 10 mV Low Range 0 3 mV Display and Readback Accuracy 25W High Range DVM 10 mV Low Range DVM 2 mV 50W High Range DVM 10 mV Low Range DVM 3 5 mV CV PROGRAMMING Full Scale Output Accuracy DVM Reading 25W High Range 50 V 18 mV Low Range 7 V 2 6 mV 50W High Range 50 V 18 mV Low Range 16 V 5 5 mV Display and Readback Accuracy 25W High Range DVM 18 mV Low Range DVM 3 1 mV 50W High Range DVM 18 mV Low Range DVM 6 06 mV CV LOAD EFFECT Gm 3 14 CV SOURCE EFFECT 5 mV RE 15 CV NOISE PARD Peak to Peak 3 mV RMS 500 uV 16 TRANSIENT RECOVERY 6755 05 mV peccare e TURN ON OFF OVERSHOOT OV s 100 m nee 19 OVERVOLTAGE PROTECTION programmable 49 V 48 44 to 49 55 V e OBESSE CC PROGRAMMING 0 Amps Output Accuracy lo 25W High Range 0 mA Low Range 0 mA 15 pA 50W High Range 0 mA 500 A Lew Range 0 mA 185 Display and Readback Accuracy 25W High Range lo 130 Low Range Io 15 4A 50W High Range Io 550 Low Range lo 250 3 22 CC PROGRAMMING Full Scale Output Accuracy Io 25W High Range 500 mA 300 A Low Range 15 mA 21 pA 50W High Range 2 A 1 3 mA Low
231. ut board interface block of Figure 2 3 is the EEPROM electrically erasable programmable memory The EEPROM U230 stores all of the system constants including calibration constants the supply s GPIB address and model number see paragraph 2 19 2 15 Real Time Clock The real time clock U209 consists of a 14 stage ripple counter that divides the 1 MHz Q clock signal from the microprocessor to produce a pulse every 4 milliseconds real time clock is used by the microprocessor to schedule regular jobs as described previously The TIMER ENABLE signal resets the counter to zero 2 16 Output Boards Interface This circuit provides the interface between the system microcomputer and each of the output boards up to 4 in the power supply Data is transferred serially one bit at a time between latches buffers on the GPIB board and optoisolators on the output boards As shown in Figure 2 3 the latches buffers use data bus lines D0 D8 to send receive data from the applicable output Data line DO is used for output board 1 D1 for output board 2 D2 for output board 3 if present and D3 for output board 4 if present A controlled and regulated 5 volt line is also generated on the GPIB board to operate art of the opto isolators on the output boards In addition to interfacing with the output boards the latches buffers interface with the 4 K bit serial EEPROM in which system constants are stored 2 17 Data Buffers These 3 state bu
232. voltages within the power supply and greatly degrade performance specifications Be sure to remove any static charge on the covers prior to installing them on the output board 4 9 Replacing the Power Module U338 Use the following procedure when it has been determined that the power module U338 is defective and must be replaced a Remove the output board as described in paragraph 4 7 Carefully unsolder all 14 power module pins c Remove the power module and heat sink from the board d Remove four power module screws and retain all hardware e Check the heat sink thermal conductor surface For minor damage apply a thin layer of heat sink compound to the back surface of the replacement power module For major damage replace the heatsink f Reassemble using the reverse of the above procedure Before soldering the new power module heat sink assembly to the board be sure that the heat sink lies flat and securely against the board Use the long heat sink screws and nuts to temporarily hold the assembly to the board while soldering 4 10 Front Panel Removal The front panel contains the keypad assembly LCD display assembly and the line switch You must remove the front panel in order to gain access to these components The LCD display and fine switch are replaceable components You will have to replace the front panel if the keypad is defective To remove the front panel assembly proceed as follows a Disconn
233. w the brackets lt gt indicate a number to be sent The lt ch gt specifies the output channel number from 1 through 4 The voltage and current values which are sent to the specified output channel are given in Table 3 2 Table 3 2 Programmable Voltage and Current Values Out Full Max Full Max Scale Prog Current Current Voltage Voltage 25W Lo Rng 15 mA 15 45 mA 50W Lo Rng 25W Hi Rng 50W Hi Rng 3 10 Constant Voltage CV Tests 3 11 CV Setup If more than one meter or a meter and an oscilloscope are used connect each to the S and S terminals by a separate pair of leads to avoid mutual coupling effects Connect only to S and S because the unit regulates the output voltage that appears between S and S not between V and V Use coaxial cable or shielded 2 wire cable to avoid noise pickup on the test leads 3 12 Voltage Programming and Readback Accuracy This test verifies that the voltage programming GPIB readback and front panel display functions are within specifications An GPIB controller must be used for the readback accuracy portions of this test a Turn off the supply and connect a digital voltmeter between the S and S terminals of the output to be tested b Turn on the supply and select the desired output OUTPUT SELECT key on the front panel SELECT the low voltage range using the range command VRSET lt ch gt lt 7 25W or 16 50W or press range and volt buttons
234. xternal supply The fixed OV circuit should trip between 56 8 V and 63 5 V e Repeat steps a through d for each output in your supply CHANNEL B S mv DIV 3 40 External OV Test This test checks the operation of the external OV circuit 1 1 i I 1 1 1 l 1 l PROGRAMMING RESPONSE TIME lt EmS TIME CONSTANT lt 75 uS a Turn off the supply and connect the OV terminals of all outputs in parallel noting proper polarity Figure 3 12 shows two outputs connected in parallel Turn on the supply and select the desired OUTPUT SELECT key on the front panel c Program the output voltage to 5 V and the OV to 4 TIME BASE 5 01 Figure 3 10 CV Up Programming Speed Test Waveforms K Repeat steps a through j for each output in the V supply VSET ch 5 3 39 Fixed OV Test This test verifies that the fixed OV OVSET ch 4 circuit will be activated when the output is about 2076 above the High Range Full Scale Voltage value d Note the display should OVERVOLTAGE for all outputs indicate a Turn off the supply and connect an external power e Reset all outputs by turning the supply off and on supply to the output to be tested as shown in again Figure 3 11 f Repeat the above tests for each channel until all B S mv DIV 1 l 1 1 1 1 l l 1 1 1 PROGRAMMING RESPONSE lt TIME CONSTANT lt 5 uS TIME BASE imS DIV Figure 3 10 CV Up Programmin
235. your supply is an Agilent board may result in damage to the supply Model 6626A 4 11 The MODEL command removes all calibration constants and substitutes default values Consequently after the MODEL command is sent you must recalibrate each output 10 OUTPUT 705 CMODE 1 20 OUTPUT 705 MODEL 6626A 30 OUTPUT 705 CMODE 0 40 OUTPUT 705 CLR 50 END After sending the above program wait until SAVING CAL is no longer displayed Next cycle the ac power to initiate a power on self test and initialize the supply then perform the calibration procedures outlined in Appendix A of the Operating Manual 4 22 Signature Analysis Testing The easiest and most efficient method of troubleshooting microprocessor based instruments is signature analysis which is similar to signal tracing with an oscilloscope in linear circuits Part of the microcomputer memory is dedicated to signature analysis and a known bit stream is generated to stimulate as many nodes as possible within the circuit However because it is virtually impossible to analyze a bit stream with an oscilloscope a signature analyzer is used to compress the bit stream into a four character signature By comparing signatures of the IC under test to the correct signatures for each node faults can usually be isolated to one or two components Signature Analysis S A Tests 1 through 8 Tables 4 6 through 4 13 respectively test most of the ci

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