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DC Power Supply HP Model 6296A Operating and Service Manual

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3. Check A Q600 through Q603 C600 CR600 and CR601 Table 5 3 High Output Voltage Troubleshooting Probable Cause 0400 Q401 shorted e CR400 shorted b Q303 open or R309 shorted Proceed to Step 2 Voltage between TP26 and TP90 OV or Se b More positive than DV OV to 0 8V Voltage between S and A4 Open strap A3 A4 R813 or R814 open R805 or R806 shorted b Proceed to Step 3 b More negative than ov More positive than 1 5V 0 9V to 4 1 5V Q1008 shorted Q100A open b Proceed to Step 4 Voltage between S and 11 More negative than DV Q302 open Q301 open R305 R300 shorted Voltage between S and 21 Table 5 4 Low Output Voltage Troubleshooting Response Probable Cause More positive than Proceed to Step 2 DN OV or negative Voltage between TP26 and TP90 Proceed to Step 3 Check fuse Fl If blown check CR502 or CR504 for short If not blown pro ceed to Table 5 5 b Q400 Q401 open Proceed to Step 3 Less positive than 4V Voltage between TP90 and TP27 More positive than SV Constant Current circuit faulty check Q200B R810 R809 for short Normal output voltage Disable Q200 by disconnect ing CR200 b If supply is furnishing cur rent without load check CR809 C802 or C803 for short If it is not proce
4. sistance is reduced rapidly 3 51 REVERSE VOLTAGE LOADING 3 52 A diode is connected across the output ter minals Under normal operating conditions the diode is reverse biased anode connected to neg ative terminal If a reverse voltage is applied to the output terminals positive voltage applied to negative terminal the diode will conduct shunt ing current across the output terminals and limit ing the voltage to the forward voltage drop of the diode This diode protects the series transistors and the output electrolytic capacitor 3 53 REVERSE CURRENT LOADING 3 54 Active loads connected to the power supply may actually deliver a reverse current to the p supply during a portion of its operating cycle external source cannot be allowed to pump current into the supply without loss of regulation and pos Sible damage to the output capacitor To avoid these effects it is necessary to preload the sup ply with a dummy load resistor so that the power supply delivers current through the entire operat ing cycle of the load device SECTION IV PRINCIPLES OF OPERATION REFERENCE VOLTAGES REFERENCE CIRCUIT INPUT TRANSFORMER NOTE DENOTES VOLTAGE FEEDBACK PATH DENOTES CURRENT FEEDBACK PATH Figure 4 1 4 1 OVERALL BLOCK DIAGRAM DISCUSSION 4 2 The power supply as shown on the overall block diagram on Figure 4 1 consists of a power transformer a rectifier preregulator filter pre re
5. 05 50 Hz Regulator Realignment Standard instruments will operate satisfactorily at both 60 and 50 Hz without adjustment However Op tion 05 factory realignment results in more efficient operation at 50 Hz and is recommended for all applica tions when continuous operation from a 50 Hz ac input is intended Option No 07 08 09 11 13 14 18 Description Voltage 10 Turn Control A single control that replaces both coarse and fine voltage controls and improves output settability Current 10 Turn Control A single control that replaces both coarse and fine current controls and improves output settability Voltage and Current 10 Turn Con trols Options 07 and 08 on same instrument Internal Overvoltage Protection Crowbar Operating and Service information is included in Appendix A at the rear of the manual Three Digit Graduated Decadial Voltage Control Control that re places 10 turn voltage control per mitting accurate resettability Three Digit Graduated Decadial Current Control Control that re places coarse and fine current con trols permitting accurate resettability 230V AC Single Phase Input Sup ply is shipped for 115V ac operation Option 18 consists of modifying the supply for 230Vac operation 1 10 ACCESSORIES 1 11 The accessories listed in the following chart may be ordered with the power supply or separately from your local Hewlett Packard field sales office refer to lis
6. EB 7505 EB 6225 Series 70 EB 3025 408 817 MTG EB 4735 Type BWH EB 1015 EB 1035 10XM EB 4705 EB 8215 EB 1045 Type CEB T O Type CEB T O Type CEB T O Type EB Type CEB T O Type CEB T O Type CEB T O 242E 3915 Type C42S EB 2405 242E 2425 EB 3925 EB 9125 EB 1145 GB 0475 EB 4325 EB 8225 EB 1155 Type 110 F4 EB 1235 EB 2745 242E 3025 242E 1035 EB 4335 EB 6205 EB 2735 Type CEA T O EB 8235 Type CEA T O EB 1535 Type C428 EB 3325 242E3R05 6296A 6 6 W 3 W tU Do mm 2 H S UP PMP ep Opp gt gt ww Pwe E PHH n ppp ona O o o mm mm aa IR C Sprague Corning A B Sprague A B m mm POPP PP gt p pm m gt Erop Sprague Sprague HLAB HLAB A B A B A B LRC A B I R C Corning A B Sprague 01121 01121 01121 01121 01121 71450 01121 63743 01121 07716 01121 01121 63743 01121 01121 01121 07716 07716 07716 01121 07716 07716 07716 56289 16299 01121 56289 01121 01121 01121 01121 01121 01121 01121 11236 01121 01121 09182 56289 56289 09182 09182 01121 01121 01121 07716 01121 07716 01121 16299 01121 56289 0686 3345 0686 3905 0686 3635 0686 7505 0686 6225 2100 0092 0686 3025 0811 1924 0686 4735 0811 1676 0686 1015 0686 1035 0811 0944 0686 4705 0686 8215 0686 1045 0757 0338 0698 3134 0757 0739 0698 5149 0698 3283 0698 5146 0811 1799 0698 3629 0686 2405 0811 1807 0686 3925 0686 9125
7. qty 1 0360 1190 Nut qty 3 2950 0144 CHANGE 22 In the replaceable parts list on page 6 7 change S1 previously changed in Change 5 to HP P N 3101 2456 On page 6 5 change Q40 to HP P N 1854 0458 CHANGE 23 This change also applies to units with serial numbers 2114A 4177 4190 and 4240 In the replaceable parts list and on the schematic for the overvoltage protection crowbar make the following changes Change C2 added in Change 20 to 2 2 uF 20 V HP P N 0180 0155 i Add C3 fxd cer 0 01 uF 10 100 V HP P N 0160 4832 It is to be mounted between the cathode of CR1 and the anode of CR2 Change CR4 toa two junction stabistor HP P N 1901 0701 CHANGE 24 In the replaceable parts list on page 6 6 change R605 to 6 8 k HP P N 0757 0750 CHANGE 25 In the replaceable parts list page 6 7 add the following mechanical assembly Barrier Strip Guard Assembly HP P N 5060 2862 aty 1 CHANGE 26 In the replaceable parts list page 6 5 change Q400 to HP P N 1854 1124 QTY 1 and Q303 to HP P N 1854 1017 CHANGE 27 In the replaceable parts list change th part number for the bias transformer from H P N 9100 2184 to HP P N 9100 4751 Note that the primary wiring colors have changed the white grey is now black yellow and the grey is now black See the figure below Figure 28a Transformer Connections For 115 Vac Operation For 230 Vac Operation a CHANGE 28 In the replaceable
8. ww 100 5 iw R313 fxd ww 10Ka 5 iw R400 Strap R401 LEAVE OPEN R500 fxd ww 8004 5 10w R501 502 fxd comp 474 5 lw RS03 fxd comp 8204 x59 iw R600 fxd comp 100K 5 iw R601 fxd met film 1Ka 1 Aw R602 871 fxd met film 1 33Ka 21 iw R603 fxd met film 2Kn 1 dw R604 806 808 fxd comp SELECTIVE 5 dw R605 608 609 610 fxd met film 6 2K 1 iw R606 fxd met film 9 31K4 1 iw R607 fxd met film 560 1 iw R611 fxd ww 3904 15 3w R700 fxd met ox 2704 596 2w R701 fxd comp 244 15 jw R702 fxd ww 2 4K4 595 3w R703 707 fxd comp 3 9Kn 5 Jw R704 fxd comp 9 1Kn 5 dw R70S fxd comp 110K 25 4w R706 fxd comp 4 74 5 lw R708 fxd comp 4 3K 5 lw R709 fxd comp 8 2Ka 45 iw R710 fxd comp 1 1Mn 25 iw R711 var ww 5Ka R712 fxd comp 12K4 45 iw R713 fxd comp 270K4 15 lw R800 fxd ww 0 334 5 40w R805 fxd ww 3Ka 15 3w R807 fxd ww 10K4 5 3w R809 810 var ww 1 8K4 204 DUAL POT R813 814 var ww 22Ka 2004 DUAL POT R816 fxd comp 43K4 5 iw R817 fxd comp 624 25 lw R818 fxd comp 27Kn 5 iw R821 fxd met film 68 1K4 1 1 8w R822 fxd comp 82K4 25 iw R823 fxd met film 15K4 1 Y8w R624 fxd comp 15Kn 25 iw R825 fxd met ox 1604 45 2w R826 fxd comp 3 3K4 15 dw R827 fxd ww 34 5 3w 1 1 2 1 1 1 1 1 1 1 3 1 1 1 2 1 1 1 2 1 3 M om M Fi e e Ret ul pu po ao pl AN pu po pl ba pu ta aS o Fa Fei Fi Fi bei bi Fi d PY UN EB 3345 EB 3905 EB 3635
9. 0360 0417 CHANGE 11 The serial prefix of the supply has been changed to 11404 This is the only change CHANGE 12 In the replaceable parts list and on the schematic change R702 to 1 5 k ww 3 W HP P N 0811 1805 and change R709 to 1 6 k 5 1 2 W HP P N 0686 1625 CHANGE 13 The standard colors for this instrument are now mint gray for front panels and rear panels and olive gray for all top bottom side and other external surfaces CHANGE 13 Cont Option X95 designates use of the former color scheme of light gray and blue gray Option A85 designates use of a light gray front panel with olive gray used for all other external surfaces New part numbers are shown above po i CHANGE 14 All primary ac connections have been removed from the circuit board and are now made directly to the transformer primaries R903 has been removed from the PC board and is now on a new terminal strip 0360 1696 mounted on the SCR heatsink assembly These changes do not affect the circuit schematic CHANGE 15 T800 has been replaced by a new transformer with a dual winding primary for 115 230 Vac operation The new transformer HP P N 06296 80091 replaces both T800 transformers previously used in this model for 115 V or 230 V operation Since it is no longer necessary to replace T800 to convert the supply from 115 to 230 V operation or vice versa Option 018 which equipped the supply for 230 V operation on ly has been
10. 0686 1145 0689 0475 0686 4325 0686 8225 0686 1155 2100 1824 0686 1235 0686 2745 0811 1953 0812 0010 0811 1816 2100 0995 2100 0998 0686 4335 0686 6205 0686 2735 0757 0461 0686 8235 0757 0446 0686 1535 0698 3625 0686 3325 0811 1224 ka k eA Mm m mA M m po d o t eam de k k kt be Kei ii Fi ut ta pod qe Met t ba ta Fa ba bi Fei b de bei bei bei Fa ta uo ta ta ka ta ta ta ta ten ka Reference Designator R828 R850 R851 854 856 859 R852 853 R857 R858 R860 863 R864 867 861 862 R866 R868 869 R870 R872 R900 R901 R902 R903 S1 S2 T700 T800 T800 T801 VR300 VR600 VR601 Description fxd fxd met fxd met fxd met fxd met fxd met fxd met fxd met fxd met fxd met var ww fxd met comp 39Kn 25 iw comp 180Kn 5 Zug comp 3Ka 5 lw comp 33Kn 5 w fxd fxd fxd fxd comp 680Kn 5 dw antit 1 film 61 9Kn 11 V8w 1 film 900 1 1 8w film 100 1 1 8w film 5 2Ka 1 dw film 9 31Ka 1 lw film 3654 1 iw film 3 40Ka 1 iw film 7504 1 VW8w film 36 5Ka 1 iw 10Kn film 2K4 1 8w Switch PL Lt red ON OFF Switch Rotary meter 3 pole 4 position Pulse Transformer Power Transformer 115V Power Transformer 230V Special for 230V opera tion only Bias Transformer Diode zener 4 22V 15 400MW Diode zener 9 4V 25 500MW Diode zener 6 2V 5 Side Chassis right
11. A measurement made across the load includes the impedance of the leads to the load and such lead lengths can easily have an impedance several orders of magnitude greater than the supply impedance thus invalidating the measurement 3 5 5 The monitoring device should be connected to the S and S terminals see Figure 3 2 or as shown in Figure 5 1 The performance characteris t cs should never be measured on the front terminals if the load is connected across the rear terminals Note that when measurements are made at the front terminals the monitoring leads are connected at A not B as shown in Figure 5 1 Failure to connect the measuring device atA willresuitin a measure ment that includes the resistance of the leads be tween the output terminals and the point of connec tion 5 6 For output current measurements the current sampling resistor should be a four terminal resis OUTPUT TERMINAL Figure 5 1 Front Panel Terminal Connections tor The four terminals are connected as shown in Figure 5 2 In addition the resistor should be of the low noise low temperature coefficient less than 30ppm C type and should be used at no more than 5 of its rated power sothat its temper ature rise will be minimized CURRENT SAMPLING TERMINALS EXTERNAL LOAD TO UNGROUNDEO TERMINAL OF POWER SUPPLY TO GROUNDED TERMINAL OF D TERMINALS Figure 5 2 Output Current Measurement Technique 5 7 When using an oscillo
12. CROWBAR ADJUST ccw until the crowbar trips output goes to OV or a small positive voltage 4 The crowbar will remain activated and the output shorted until the supply is turned off To reset the crowbar turn the supply off then on MPB 5 Table A 1 fxd film 1uF 200Vdc Diode Si 200mA 200prv Rect Si 12A 100prv SCR B 200prv SS NPN Si SS NPN Si SS PNP Si fxd comp 7504 5 W fxd comp 200K 5 Aw fxd comp 10K 59 W fxd comp 3 9K4 25 3W fxd comp 4 74 15 3W fxd comp 474 5 1W fxd met ox 1804 5 2W fxd met film 2K4 11 1 8W fxd comp 3 3Ka 1 1 8W var ww 22Ka 10 2W fxd ww D Ba 5 SW fxd comp 200K4 59 Aw Pulse Transformer Diode zener 5 62V 15 MISCELIANEOUS Bushing Potentiometer Nut Hex Printed Circuit Board Assembly Includes Components Printed Circuit Board Bracket Modified Front Panel Includes Components Replaceable Parts 6296A A 2 MFR PART NO 192P10492 1N485B 1N1200A 2N3669 2N2714 2N 3417 T2173 EB 7515 EB 2045 EB 1035 EB 3925 EB 47G5 C425 Type C428 Type CEA T O 242E3325 EB 2045 1N3512 0160 0168 1901 0033 1901 0002 1884 0019 1854 0027 1854 0087 1853 0099 0686 7515 0686 2045 0686 1035 0686 3925 0698 0001 0698 3626 0698 3626 0757 0283 0811 1809 2100 1850 0811 1848 0686 2045 9100 1824 1902 3104 1400 0052 2950 0034 06296 60021 5000 6225 06296 60003 FROM TP44 15 vH
13. POINT 1 smalt pe L 22M LEVEL L LATER FIRING POINT Figure 4 3 SCR Phase Control of DC Input Level 4 13 The SCR control circuit See Figure 4 4 samples the input line voltage the output voltage and the voltage across the series transistor It generates a firing pulse at the time required to fire the SCR so that the voltage across input capacitor C500 will be maintained at the desired level 4 14 The inputs to the control circuit are algebra ically summed across capacitor C700 All inputs contribute to the time required to charge C700 The input line voltage is rectified by CR704 through CR707 attenuated by voltage divider R700 and R701 and applied to the summing point at TP 59 via capacitor C700 Capacitor C701 is used for smoothing purposes 4 15 Transistor Q702 connected in a common base configuration provides a charging current for the summing capacitor which varies in accord ance with the input signals applied to its emitter pus P O R708 R713 T801 y R702 52 EA 00 S R710 CR CR 09 Canes eh 10 11 ea Figure 4 4 Resistor R713 connected between the negative output line and the emitter of Q702 furnishes a signal which is proportional to the output voltage Resistors R708 and R707 sample the voltage across and the current through the series regu lator Capacitor C702 and resistor R709 stabi lize the control circuit feedback loop Resistors R711 and R712 are the source of
14. Symptom Checks and Probable Causes Check operating setup for ground loops If output floating connect luf capacitor between output and ground Ensure that supply is not crossing over to constant current mode High ripple under loaded conditions Check for low voltage across C500 or Q400 Check for excessive ripple on reference voltages Peak to peak ripple should be less than 2mV for 9 4V and 6 2V and less than 4mV for 415 4V Poor line regulation a Check reference circuit Paragraph 5 31 a Measurement technique Paragraph 5 16 Poor load regulation b Check reference circuit Paragraph 5 31 Constant Voltage c Ensure that supply is not going into current limit Check constant current input circuit DPP ZS a Check reference circuit Paragraph 5 31 Poor load regulation b C802 C803 and CRB09 leaky Constant Current c Ensure that supply is not crossing over to constant voltage opera tion Check constant voltage input circuit ill we nM a Check C301 for open adjustment of R307 Paragraph 5 50 Current b Check R103 C100 or R304 C300 a Check reference voltages Paragraph 5 31 b Noisy programming resistors R813 R814 CR100 CR101 leaky Poor Stability e d Check R104 R805 R806 C801 for noise or drift Constant Voltage e Stage Q100 defective a Check reference voltages Paragraph 5 31 b Noisy programming resistors R809 R810 es Seale t c CR808 C803 C8
15. a constant offset current which sustains a net negative charging current to the summing point ensuring that the SCR s will fire at low output voltages 4 16 The summation of the input signals results in the generati n of a voltage waveform at TP 59 similar to that shown on Figure 4 5 When the linear ramp portion of the waveform reaches a certain negative thresbold voltage diodes CR711 and CR710 become forward biased The negative voltage then is coupled to the base of transistor Q701 Transistors Q701 and Q700 form a squaring circuit resembling a Schmitt trigger configuration Q701 is conducting prior to firing time due to the positive bias connected to its base through R705 Transistor Q700 is cutoffat this time be cause its base is connected directly to the collec tor of conducting transistor Q701 When the neg ative threshold voltage is reached transistor Q701 1s turned off which turns Q700 on The conduction of Q700 allows capacitor C703 to dis charge rapidly through pulse transformer T700 resulting in the SCR firing pulse shown on the 4 4 CR711 CR710 R830 O V O O ev FIRING PULSE CR500 TO SCR S Li Q700 R706 SCR Control Circuit Simplified Schematic TPS9 SUMMING POINT TP47 OUTPUI Q700 SEE NOTE 3 t 1 l l TP45 i i FIRING PULSE l Y EXPANDED E i I TPS2 ae YE RESET 19v 1 ALL WAVEFORMS REFERENCED TO INBOARD SIDE OF CURRENT SAM PLING RESISTOR R800 EX
16. amps LOAD REGULATION Constant Voltage Less than 0 01 plus 1mV for a full load to no load change in output current Constant Current Less than 0 05 plus 1mA for a zero to maximum change in output voltage LINE REGULATION Constant Voltage Less than 0 01 plus 1mV for any line voltage change within the input rating Constant Current Less than 0 05 plus 1mA for any line voltage change within the input rating RIPPLE AND NOISE Constant Voltage Less than 500 V rms Constant Current Less than 3mA rms OPERATING TEMPERATURE RANGES Operating 0 to 500C Storage 20 to 850C TEMPERATURE COEFFICIENT Constant Voltage Less than 0 02 plus 500yuV per degree Centigrade Constant Current Less than 0 02 plus 1 5m per degree Centigrade STABILITY Constant Voltage Less than 0 10 plus 2 5mV total drift for 8 hours after an initial warm up time of 30 minutes at constant ambient con stant line voltage and constant load Constant Current Less than 0 10 plus 7 5mA total drift for 8 hours afteran initial warm up time of 30 minutes at constant ambient con stant line voltage and constant load INTERNAL IMPEDANCE AS A CONSTANT VOLTAGE SOURCE Less than 0 001 ohm from DC to 100Hz Less than 0 01 ohm from 100Hz to 1kHz Less than 0 2 ohm from 1kHz to 100kHz Less than 2 0 ohms from 100 kHz to 1 MHz TRANSIENT RECOVERY TIME Less than 50usec for output recovery to with
17. current setting exceeded the slave s 3 42 AUTO TRACKING OPERATION See Figure 3 12 S A3 A4 AS A5 A7 AB Al S A2 Vl MASTER 2 4 a a o e G e 8 ole o 5 sov WV Mi G S A3 MAS A6 A AB MASTER MUST BE MOST POSITIVE SUPPLY Figure 3 12 Auto Tracking Two Units 3 43 The Auto Tracking configuration is used when it is necessary that several different volt ages referred to a common bus vary in proportion to the setting of a particular instrument the con trol or master A fraction of the master s output voltage is fed to the comparison amplifier of the slave supply thus controlling the slave s output The master must have the largest output voltage of any power supply in the group must be the most positive supply in the example shown on Figure 3 12 3 44 The output voltage of the slave is a percent age of the master s output voltage and is deter mined by the voltage divider consisting of Rx and the voltage control of the slave supply Rp where Eg Rp Rx Rp Turn on and turn off the power supplies is controlled by the master Remote sensing and programming can be used although the Strapping patterns for these modes show only local sensing and programming In order to maintain the temperature coefficient and stability specifications of the power supply the external resistors should be stable low noise low temperature less than 30 ppm per C resistors 3 45 SPECIAL OP
18. e Turn range switch on AC voltmeter to 1mV position f The AC voltmeter should read as follows Readings are expressed in mVac Model 6282A 6285A 6286A 6290A 6291A 6296A Reading 0 50 0 60 0 50 1 0 0 6 1 0 5 25 TROUBLESHOOTING 5 26 Components within Hewlett Packard power supplies are conservatively operated to provide maximum reliability In spite of this parts with in a supply may fail Usually the instrument must be immediately repaired with a minimum of down time and a systematic approach as outlined in succeeding paragraphs can greatly simplify and speed up the repair e 5 27 TROUBLE ANALYSIS 5 28 General Before attempting to trouble shoot this instrument ensure that the fault is with the instrument and not with an associated circuit The performance test Paragraph 5 10 enables this to be determined without having to remove the in strument from the cabinet 5 29 Once it is determined that the power supply is at fault check for obvious troubles such as open fuse a defective power cable or an input power failure Next remove the top and bottom covers each held by four retaining screws and inspect for open connections charred components etc If the trouble source carmot be detected by visual inspection follow the detailed procedure outlined in succeeding paragraphs Once the de fective component has been located by means of visual inspection or trouble analysis correct it and re conduct the performance
19. follows a Connect test setup shown in Figure 5 4 with switch S1 closed f Insert load resistor Ry by opening switch S1 Also add the following note The short circuit protection circuit in this supply will be activated if switch S1 is closed instead of opened during this test On page 5 8 in Step 3 of Table 5 4 change the text to read If it is not proceed to Step 4 Page 2 HP P N 06296 90001 changes continued i ERRATA ERRATA In the parts list on page 6 5 On the schematic diagram indicate that t nominal value for R313 is 1 k The o Change C501 to HP P N 0160 0710 value for R313 is factory selected to op Change C200 to fxd film 01 uF 200 V tinize the range of transient adjust pot HP P N 0160 0161 R307 Change the listing for Q702 800 850 852 853 to 2N2907A Sprague 56289 HP P N 1853 In Appendix A change Figure A 1 Overvoltage 0099 Protection Crowbar to appear as shown below Change the part number for C803 to 0180 1986 oc rowensumy sesa and its voltage rating to 85 V Add pilot light DS1 HP P N 1450 0566 Change SCR CR502 and CR504 from HP P N 1884 0019 to P N 1884 0347 On page 6 7 Add R865 var ww 250 ohm HP P N 2100 0439 Also add Spacer round HP P N 0380 1551 and Internal external lockwasher HP P N 2190 0576 Delete the two types of binding posts list and add the following black binding post HP P N 1510 0114 qty 2 red binding post HP P N 1510 0115 Add Insulator CR502 50
20. modification to the instrument Return the instrument to a Hewlett Packard 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 Section I 11 111 IV Page No GENERAL INFORMATION 1 1 1 1 Description 1 1 1 6 Specifications l i 1 8 Options 1 1 1 10 Accessories 1 2 1 12 Instrument Identification 1 2 1 15 Ordering Additional Manuals 1 2 INSTALLATION 2 1 2 1 Initial Inspection 2 1 2 3 Mechanical Check 2 1 2 5 Electrical Check 2 1 2 7 Installation Data 2 1 2 9 Location 2 1 2 11 Rack Mounting 2 1 2 15 Input Power Requirements 2 2 2 17 50Hz Operation 2 2 2 19 Power Cable 2 2 2 22 Repackaging for Shipment 2 2 3 1 3 3 3 5 3 7 3 9 3 11 3 14 3 16 3 17 3 24 3 30 3 35 3 39 3 42 3 45 3 46 3 48 3 51 3 53 4 1 TABLE OF CONTENTS OPERATING INSTRUCTIONS 3 1 Operating Controls and Indicators 3 1 Operating Modes 3 1 Normal Operating Mode 3 1 Constant Voltage 3 1 Constant Current 3 1 Connecting Load 3 2 Operation of Supply Beyond Rated Output 3 2 Optional Operating Modes 3 2 Remote Programming Constant Voltage 3 2 Remote Programming Constant Current 3 3 Remote Sensing 3 3 Series Operation 3 4 Parallel Operation 3 5 Auto Tracking Operation 3 5 Special Operating Considerations3 6 P
21. test If a compo nent is replaced refer to the repair and replace ment and adjustment and calibration paragraphs in this section 5 30 A good understanding of the principles of operation is a helpful aid in troubleshooting and it is recommended that the reader review Section IV of the manual before attempting to troubleshoot the unit in detail Once the principles of operation are understood logical application of this knowledge used in conjunction with the normal voltage readings and waveforms shown on the schematic and the ad ditional procedures given in the following para graphs should suffice to isolate a fault to a compo went or small group of components The component location diagram at the rear of the manual can be consulted to determine the location of components and test points The normal voltages shown on the schematic are positioned adjacent to the applicable test points identified by encircled numbers on the schematic and component location diagram Addi tional test procedures that will aid in isolating troubles are as follows a Reference circuit check Paragraph 5 31 This circuit provides critical operating voltages for the supply and faults in the circuit could affect the overall operation in many ways This circuit should be checked first before proceeding to other areas of the unit b Series regulator and preregulator feedback loop checks Paragraph 5 32 c Procedures for dealing with common troubl
22. the voltage limit allowance must be made for high peak voltages which can cause unwanted crossover Refer to Paragraph 3 46 NOTE When Model 6291A is operated continuously in the crossover region between Constant Voltage Con stant Current the feedback loop may break into os cillation particularly in the 0 5A to 1 5A output current range Although the crossover region is not usually an area of continuous operation this prob lem can be eliminated if necessary by connecting the emitter of Q300 to 4S instead of to the emitter of Q301 and readjusting R307 Note that when this is done the transient recovery time of Model 6291A must be derated to SOusec for recovery to within 25mV instead of 15mV 3 11 CONNECTING LOAD 3 12 Each load should be connected to the power supply output terminals using separate pairs of connecting wires This will minimize mutual cou pling effects between loads and will retain full advantage of the low output impedance of the power supply Each pair of connecting wires should be as short as possible and twisted or Shielded to reduce noise pickup If shield is used connect one end to power supply ground terminal and leave the other end unconnected 3 13 If load considerations require that the out put power distribution terminals be remotely located from the power supply then the power supply output terminals should be connected to the remote distribution terminals via a pair of twisted o
23. ultimately varies the conduction of the series regulator 4 25 Resistor R104 in series with the base of Q100B limits the current through the programming resistors during rapid voltage turn down Diodes CR100 and CR101 form a limiting network which prevents excessive voltage excursions from over driving stage Q100B Capacitor C801 shunting 15 4V 6 2V R208 R203 To CR200 GATING CIRCUIT 67 R304 R204 ep un R203 om o2008 Gei R206 C200 BK Figure 4 7 Constant Current Input Circuit Simplified Schematic the programming resistors increase the high frequency gain of the input amplifier Resistor R806 shunting the pullout resistor serves as a trimming adjustment for the programming current Diode CR102 establishes the proper collector m o for Q100A while R103 and C100 provide low fre quency equalization for the feedback loop 4 26 CONSTANT CURRENT INPUT CIRCUIT See Figure 4 7 4 27 This circuit is similar in appearance and Operation to the constant voltage input circuit It cons sts of the coarse and fine current program ming resistors R809 and R810 and a differential amplifier stage Q200 and associated components Like transistor Q100 in the voltage input circuit Q200 consists of two transistors having matched characteristics that are housed in a single pack age 4 28 The constant current input circuit continu ously compares a fixed reference voltage with the voltage drop across the current sam
24. which is activated only if the constant current input circuit should fail Q802 monitors the volt age drop across the current sampling resistor and conducts if this drop exceeds a certain level The output of Q802 is fed to gating amplifier Q301 via R815 and ultimately reduces the conduction of the series regulator 4 41 Short circuit protection is provided by tran sistors Q801 and Q802 Transistor Q801 normal ly biased below cutoff monitors the voltage drop across the series regulator Under short circuit conditions the increased voltage across the reg ulator drives Q801 into saturation The positive going emitter voltage of Q801 also drives Q802 into conduction The output of Q802 limits the current flow through the series regulator to a pre scribed level 4 42 REFERENCE CIRCUIT See Schematic at Rear 4 43 The reference circuit is a feedback power supply similar to the main supply It provides stable reference voltages which are used through Out the unit The reference voltages are all derived from smoothed de obtained from the full wave rectifier CR600 and CR601 and filter capac itor C600 The 9 4 and 6 2 voltages are devel oped across temperature compensated Zener diodes VR600 and VR601 Resistor R611 limits the current through the Zener diodes to establish an optimum bias level 4 44 The regulating circuit consists of series regulating transistor Q600 error ammplifier Q601 and differential amplifier Q602 and Q60
25. 02 leaky SEENEN d Check R807 R808 R200 R800 for noise or drift e Stage Q200 defective Table 5 7 Selected Semiconductor Characteristics Matched differential ampli fier NPN Si Planar 70 min hrgic 1mA Vers SV 1854 0229 NPN power hpp 35 min x Ol 4A Vor 4V 1854 0225 Matched differential amplifier NEN Si 1854 0221 Ico 0 01 ua O Vebo SV 5 10 Suggested Replacement Reference Designator Q100 Q200 2N2917 G E Q303 Q400 Q401 2N3055 R C A 2N4045 Union Carbide Table 5 7 Selected Semiconductor Characteristics Continued CR100 CR102 CR200 CR300 CR301 Si diode 200 mA 200 prv 1901 0033 1N485B Sylvania CR500 CR700 CR701 CR402 CR602 CR803 CR806 Si Stabistor 200 mA 15 prv 1901 0461 1N4828 G E Zener diode 4 22V 596 400 mw 1902 3070 1N749 Motorola Table 5 8 Checks and Adjustments After Replacement of Semiconductor Devices wes re A en Constant voltage CV EM Constant voltage differential amplifier line and load nei M DS Constant current CC Constant current differential amplifier line and load regulation d Constant Current gating Constant Current gating amplifier CC load regulation A Constant Voltage gating amplifier CV load regulation EE Cv cC load regulation Q400 Qa00 Q40 Series series Regulator CV CC load regulation load regulation Q600 Q601 1 Reference voltages Q602 Q603 Reference r
26. 1785 assigned to Cinch Mfg Co Chicago Ill 6 3 Table 6 3 Code List of Manufacturers Continued CODE No MANUFACTURER ADDRESS 76530 Cinch City of Industry Calif Oak Mfg Co Div of Oak Electro Netics Corp Crystal Lake Ill Bendix Corp Electrodynamics Div No Hollywood Calif Palnut Co Mountainside N J Patton MacGuyer Co Providence R L Phaostron Instrument and Electronic Co South Pasadena Calif Philadelphia Steel and Wire Corp Philadelphia Pa American Machine and Foundry Co Potter and Brumfield Div Princeton Ind TRW Electronic Components Div Camden N J Resistance Products Co Harrisburg Pa Illinois Tool Works Inc Shakeproof Div Elgin Ill Everlock Chicago Inc Chicago Ill Stackpole Carbon Co St Marys Pa Stanwyck Winding Div San Fernando Electric Mfg Co Inc Newburgh N Y Tinnerman Products Inc Cleveland Ohio Stewart Stamping Corp Yonkers N Y Waldes Kohinoor Inc L 1 C N Y Whitehead Metals Inc New York N Y Continental Wirt Electronics Corp Philadelphia Pa Zierick Mfg Co Mt Kisco N Y Mepco Div of Sessions Clock Co Morristown N J Bourns Inc Riverside Calif Howard Industries Div of Msl Ind Inc Racine Wisc Grayhill Inc La Grange Ill International Rectifier Corp El Segundo Calif Columbus Electronics Corp Yonkers N Y Goodyear Sundries amp Mechanical Co Inc New York N Y Airco Speer Electronic Components Du Bois Pa Sylvan
27. 2 This power supply is completely tran sistorized and suitable for either bench or relay rack operation It is a compact well regu lated Constant Voltage Constant Current supply that will furnish full rated output voltage at the maximum rated output current or can be continuous ly adjusted throughout the output range The front panel CURRENT controls can be used to establish the output current limit overload or short circuit when the supply is used as a constant voltage source and the VOLTAGE control can be used to establish the voltage limit ceiling when the sup ply is used as a constant current source The supply will automatically crossover from constant voltage to constant current operation and vice versa if the output current or voltage exceeds these preset limits 1 3 The power supply has both front and rear terminals Either the positive or negative output terminal may be grounded or the power supply can be operated floating at up to a maximum of 300 volts off ground 1 4 A single meter is used to measure either out put voltage or output current in one of two ranges The voltage or current ranges are selected by a METER switch on the front panel 1 5 Barrier strip terminals located at the rear of the unit allow ease in adapting to the many oper ational capabilities of the power supply A brief description of these capabilities is given below a Remote Programming The power supply may be programmed from a remote
28. 3 The voltage across the Zener reference diode VR600 and the voltage at the junction of divider R605 and R606 are compared and any differences are de R85 6 2V 15 4v NOTE S2 POSITIONS FOR DIFFERENT MODELS ARE SHOWN BELOW Figure 4 8 Meter Circuit Simplified Schematic 4 8 tected by Q602 and Q603 The error voltage is amplified and inverted by Q601 and applied to series regulator Q600 in the correct phase and amplitude to maintain the 15 4 volt output stant 4 45 Zener diode VR601 provides an additional bias voltage of 6 2 volts Resistor R601 con nected across Q600 minimizes power dissipation in the series element Output capacitor C602 stabilizes the reference regulator loop 4 46 METER CIRCUIT 4 47 The meter circuit see Figure 4 8 provides continuous indications of output voltage or cur rent on a single multiple range meter The meter can be used either as a voltmeter or an ammeter depending upon the position of METER switch S2 on the front panel of the supply This switch O also selects one of two meter ranges on each scale The metering circuit consists basically of a selection circuit switch S2 and associated voltage dividers a stable differential amplifier stage Q851A and Q8518 two meter amplifiers Q852 and Q853 and the meter movement 4 48 The selection circuit determines which voltage divider is connected to the differential amplifier input When S2 is in one of the
29. 4 HP P N 5020 5595 For all instruments delivered on or after July 1 1978 change the HP P N for fuseholder from 1400 0084 to fuseholder body 2110 0564 and fuseholder carrier 2110 0565 On page 6 1 Change the HP P N for fuseholder nut from 2950 0038 to 2110 0569 If old fuseholder must be replaced for any reason replace complete fuseholder and nut with new fuseholder parts Do not replace new parts with old parts On page 6 8 note that effective January 1 i 1977 Options 007 10 turn voltage control and 008 10 turn current control are no longer available individually but are still available combined as Option 009 Likewise Options 013 10 turn voltage control with decadial are no longer available in dividually but are available combined into a single new option designated Option 015 Make these changes wherever Option 007 008 013 or 01 is mentioned in the manual e Page 3 HP P N 06296 90001 changes continued CHANGE 1 page 6 5 change C500 from 10 000 uF to 000 uF HP P N 0180 1929 CHANGE 2 On the component location drawing schematic apron make the following changes a Interchange collector C and emitter E designations for transistor Q853 on the lower right hand side of drawing b Remove TP21 designation from R205 on center left hand side of drawing The TP21 designation at the bottom of R310 is unchanged C TP19 bottom center should point to bottom of R300 d Intere
30. 6 04087 04246 04247 04486 04487 04926 04927 05566 05567 05916 05917 06036 06037 06146 06147 06206 06207 up ep ep O E em e a Il PXLI IPI 1 22 23 ta CHANGES 27 29 o MAKE TONS 1 3 e VI a N w ch A o 1 10 1 11 1 12 1 13 1 14 1 15 1 16 1 17 1 18 1 19 1 20 1 21 1 23 1 24 1 25 1 26 1 27 1 28 1 29 ERRATA In Table 1 1 and paragraph 5 20 change the INTERNAL IMPEDANCE AS A CONSTANT VOLTAGE SOURCE Output Impedance specification to read OUTPUT IMPEDANCE TYPICAL Approximated by a5 milliohm resistance in series with a 1 microhenry inductance On page 3 2 Figure 3 4 disconnect strap between terminals AU and A5 and connect AS to S On page 3 3 Figure 3 6 disconnect strap between terminals A7 and A8 and con nect AB S Add the following note to paragraph 3 18 on page 3 2 and to paragraph 4 41 on page 4 7 A protection circuit which protects the series regulator from overload damage is ac tivated whenever 1 a short is placed across the supply or 2 the output is rapidly down programmed by an increment of more than 4 to 10 volts When activated the protection circuit limits the supply s output current to about 10 of rating for a period of from 0 5 to 10 seconds depending on the model and the load conditions On page 5 6 paragraph 5 22 change steps a and f as
31. 757 0765 2100 0396 0757 0283 0686 3935 0686 1845 0686 3025 0686 3335 3101 0100 3100 1910 9100 1824 9100 1846 9100 2141 9100 1832 1902 3070 1902 0762 1902 0761 5000 6098 5000 6099 5000 6103 5000 6100 5000 6101 5000 6102 5000 6104 5020 5540 1120 1146 4040 0294 1460 0256 1400 0084 2190 0037 2950 0038 1400 0090 1510 0040 1510 0039 0403 0088 0370 0084 d ka pr ta m bad ka ta tata t ba ta td bg La be ba Fa b ta ul Reference Designator Description Knob pointer SCH dia Knob dia red Barrier strip Line cord 7 PH 151 Strain relief Mica washer Mica washer 1 dia Capacitor clamp 3 dia Mica washer 9 8 dia Fastener U type Cable clamp 78 I D Cable clamp 1 1 D Delrin bushing Delrin bushing Pem nuts 48 32 Pem nuts 46 32 Jumper barrier strip Handle 8 black color no Y 12561 OPTION 07 Voltage 10 Turn Potentiometer OPTION 08 Current 10 Turn Potentiometer OPTION 09 Voltage Current 10 Turn Pot Voltage 10 Turn Potentiometer Current 10 Turn Potentiometer OPTION 13 Voltage Decadial Control Voltage 10 Turn Potentiometer Decadial Control OPTION 14 Current Decadial Control Current 10 Turn Potentiometer Decadial Control uanti wd 9 DHMH OY BH ti bd amp NN T Mfr Part or T KH 4096 SR SP 1 734 4586 2A 6 32 T4 6 T4 4 CLA 832 2 CLA 632 2 422 13 11 013 7835 Series 8400 Series 8400 Includes Series 8400 Se
32. 9 4 volts CHANGE 5 The serial number prefix of the instrument has been changed from 7D to 7M In the parts list delete S1 switch indicator ON OFF and replace with a separate toggle switch and pilot light as follows l S1 toggle switen Carling 2FA53 73 SKI HP P N 3101 0984 DS1 pilot light Neon Sloan HP P N 1450 0048 Schematic connections to the new switch and pilot light remain the same except that the two are physcially separate Page 4 HP P N 06296 90001 changes continued i 3 HP PART NO i DESCRIPTION A a o a tant i i STANDARD i OPTION A85 OPTION X95 i Y o o ms Front Panel Lettered 06296 60004 06296 60001 Heat Sink Assembly 5060 7968 5060 6131 Rear Chassis 5000 9485 j 5000 6103 iCover Top 5000 9431 i 5000 6108 1 Chassis Right Side i 5000 9406 5000 6098 i Chassis Left Side 5000 9407 4 5000 6099 CHANGE 6 In the parts list change R309 to 125 ohm 40 W HP P N 0811 2621 CHANGE 7 In the parts list change R826 to 3 9 k 54 1 2 W HP P N 0686 3925 CHANGE 8 In the parts list change R816 to 56 k 5 1 2 W AB HP P N 0686 5635 CHANGE 9 In the parts list and on the schematic change R501 and R502 to 22 ohm 5 1 2 W HP P N 0686 2205 CHANGE 10 In the parts list delete Cable Clamp HP P N 1400 0332 qty 2 and add Terminal Strip HP P N
33. CEPT FIRING PULSE WHICH IS REFER ENCED TO 1 P 45 2 FOR CLARITY WAVEFORMS ARE NOT DRAWN TO SCALE 3 AMPLITUDE OF THIS WAVEFORM IS APPROXIMATE AND VARIES SLIGHTLY FROM MODEL TO MODEL 1N AC CORDANCE WITH THE POSITIVE COLLECTOR BIAS OBTAINED FROM C800 Figure 4 5 SCR Control Circuit Waveforms o diagram The firing puise is relatively narrow be cause Q700 saturates rapidly causing the magnetic field surrounding T700 to collapse Diode CR500 damps out the negative overshoot 4 17 Reset of the control circuit occurs once every 8 33 milliseconds when the rectified ac voltage at test point 52 recedes to a level at which diode CR709 becomes forward biased Summing capacitor C700 is then allowed to dis charge through CR709 Diodes CR711 and CR710 become reverse biased at reset and transistor Q701 reverts to its on state Consequently Q700 is turned off and capacitor C703 charges up through R703 at a comparatively slow rate until the collector voltage of Q700 reaches approximately 17 volts The above action causes the small negative spike that appears across the winding of pulse transformer T700 at reset time 4 18 Capacitor C900 diode CR900 and resistor R900 form a long time constant network which achieves a slow turn on characteristic When the unit 1s first turned on C900 provides a positive voltage to the cathode of CR711 to ensure that it is initially reverse biased After C900 becomes fully charged the control circui
34. CIRCUIT PATENTS APPLIED FOR LICENSE TO USE MUST BE OBTAINED IN WRITING FROM MEWLETT NOTES LALL RESISTORS ARE IN OHMS Vie 23 PACKARD CO HARRISON DIVISION UNLESS OTHERWISE NOTED 2 ALL CAPACITORS ARE IN MICROFARADS UNLESS OTHERWISE NOTED Figure A 1 Model 6296A Overvoltage Protection Crowbar D i Printed in USA Order Part Number Manufacturing Part Number 206 06296 90001 06296 900 EI266 U 1090 LL T T IE E T AT E IAM
35. Connect load resistor across rear output terminalofsupply Resistor value to be as follows Model 6282A 6285A 6286A 6290A 6291A 6296A Res la an 2 134 Ba 20 b Connect oscilloscope dc coupled across series regulator T P 27 to T P 90 c Disconnect R709 inthe SCR control circuit and connect decade resistance box in its place d Rotate CURRENT controls fully clockwise and turn on supply e Decrease resistance of decade resistance from normal value of R709 until sawtooth waveform on oscilloscope is symmetrical amplitude of S0Hz sawtooth waves are equal f Replace decade resistance box with ap propriate value resistor in R709 position g Adjust ramp potentiometer R711 for 3 5Vdc drop across series regulator h If 3 5 volts cannot be obtained remove R712 in series with R711 and connect the decade resistance box in its place i Increase value of decade resistance box from normal value of R712 until 3 5Vdc drop is ob tained across series regulator j Remove decade resistance and connect new resistance value in R712 position e SECTION VI REPLACEABLE PARTS 6 1 INTRODUCTION 6 2 This section contains information for ordering replacement parts Table 6 4 lists parts in alpha numeric order by reference designators and provides the following information a Reference Designators Refer to Table 6 1 b Description Refer to Table 6 2 for ab breviations c Total Quantity TQ Given only the first time t
36. ERATING CONSIDERATIONS 3 46 PULSE LOADING 3 47 The power supply will automatically cross over from constant voltage to constant current op eration or the reverse in response to an increase over the preset limit in the output current or volt age respectively Although the preset limit may be set higher than the average output current or voltage high peak currents or voltages as occur in pulse loading may exceed the preset limit and cause crossover to occur If this crossover limit ing is not desired set the preset limit for the peak requirement and not the average 3 48 OUTPUT CAPACITANCE 3 49 An internal capacitor connected across the Output terminals of the power supply helps to sup ply high current pulses of short duration during constant voltage operation Any capacitance added externally will improve the pulse current capability but will decrease the safety provided by the con Stant current circuit A high current pulse may damage load components before the average output 3 50 The effects of the output capacitor during 3 6 current is large enough to cause the constant cur rent circuit to operate a The output impedance of the power supply decreases with increasing frequency constant current operation are as follows b The recovery time of the output voltage is longer for load resistance changes c A large surge current causing a high pow er dissipation in the load occurs when the load re
37. K MOUNTING 2 4 This check should confirm that there are no 2 12 This instrument may be rack mounted in a broken knobs or connectors that the cabinet and standard 19 inch rack panel either alongside a sim panel surfaces are free of dents and scratches and ilar unit or by itself Figures 2 1 and 2 2 show how that the meter is not scratched or cracked both types of installations are accomplished 2 5 ELECTRICAL CHECK 2 13 To mount two units side by side proceed as 2 6 Theinstrumentshould be checked against its follows electrical specifications SectionV includes an in a Remove the four screws from the front cabinet performance check to verify proper instrument panels of both units operation b Slide rack mounting ears between the front panel and case of each unit 2 7 INSTALLATION DATA c Slide combining strip between the front 2 8 The instrument is shipped ready for bench panels and cases of the two units operation It is necessary only to connect the in d After fastening rear portions of units to gether using the bolt nut and spacer replace pan el screws Figure 2 1 Rack Mounting Two Units METER CUARENT VOLTS AOS 9664 cosase vi ro Aen Aen CONE 6 Figure 2 2 Rack Mounting One Unit 2 14 To mount a single unit in the rack panel proceed as follows a Bolt rack mounting ears combining straps and angle brackets to each side of center spacing panels Angle brackets are placed be hind
38. OGRAMMING Remote programming of the supply output at approximately 300 ohms per volt in constant volt age is made available at the rear terminals In constant current mode of operation the current can be remotely programmed at approximately 500 ohms per ampere COOLING Convection cooling is employed The sup ply has no moving parts SIZE 53 H x 16 Dx 81 W Two of the units can be mounted side by side in a standard 19 relay rack WEIGHT 29 lbs net 38 lbs shipping FINISH Light gray front panel with dark gray case POWER CORD A three wire five foot power cord is pro vided with each unit SECTION 1 INSTALLATION 2 1 INITIAL INSPECTION strument to a source of power and it is ready for operation 2 2 Before shipment this instrument was inspected and found to be free of mechanical and electrical 2 9 LOCATION defects As soon as the instrument is unpacked in spect for any damage that may have occurred in transit Save all packing materials until the inspec tion is completed If damage is found proceed as described in the Claim for Damage in Shipment sec tion of the warranty page at the rear of this manual 2 10 This instrument is air cooled Sufficient space should be allotted so that a free flow of cooling air can reacn the sides and rear of the instrument when itis inoperation It shouldbe usedin an area where the ambient temperature does not exceed 50 C 2 3 MECHANICAL CHECK 2 11 RAC
39. RENT RANGE AND SHORT CIR CUIT OUTPUT TERMINALS ADJUST CURRENT CONTROLS FOR DESIRED OUTPUT CURRENT h REMOVE SHORT AND CONNECT LOAD TO OUTPUT TERMINALS ITRONT OR REAR Figure 3 1 Front Panel Controls and Indicators 3 3 OPERATING MODES 3 4 The power supply is designed so that its mode of operation can be selected by making strapping connections between particular terminals on the terminal strip at the rear of the power sup ply The terminal designations are stenciled in white on the power supply above their respective terminals Although the strapping patterns illus trated in this section show the positive terminal grounded the operator can ground either terminal or operate the power supply up to 300 vdc off ground floating The following paragraphs de scribe the procedures for utilizing the various operational capabilities of the power supply A more theoretical description concerning the oper ational features of this supply is contained in a power supply Application Manual and in various Tech Letters published by the Harrison Division Copies of these can be obtained from your local Hewlett Packard field office 3 5 NORMAL OPERATING MODE 3 6 The power supply is normally shipped with its rear terminal strapping connections arranged for Constant Voltage Constant Current local sensing local programming single unit mode of operation This strapping pattern is illustrated in Figure 3 2 The operator selects eit
40. Side Chassis left Chassis rear Panel front Heat sink diode Heat sink SCR Cover Guard angle Meter 34 DUAL SCALE 0 70V 0 4A Meter bezel 1 mod Meter spring Fuseholder Lockwasher Nut Washer neoprene Binding post maroon Binding post black Rubber feet Knob Y8 dia black NH o PN d ESAS 1 ke hs ka Ga bd OM om mS m Me bn Rh mn e m tat Mfr Part 4 6 7 or Type Mfr EB 6845 A B Type CEA T O LRC Type CEA T O LRC Type CEA T O LR C Type CEB T O LRC Type CEB T O LRC Type CEB T O LRC Type CEB T O LRC Type CEA T O LRC Type CEB T O LRC Type 110 F4 C T S Type CEA T O LR C EB 3935 A B EB 3935 A B EB 3935 A B EB 3935 A B 54 61681 26A1H Oak HLAB HLAB HLAB HLAB HLAB HLAB 1N2163 U S Semcor 1N821 N A Electric HLAB HLAB HLAB HLAB HLAB HLAB HLAB HLAB HLAB HLAB HLAB 342014 Littlefuse 1224 08 Shakeproof 903 12 Littlefuse 901 2 Littlefuse DF21Mn HLAB DF21 BC Superior MB 50 Stockwell HLAB 6296A Mfr Code 01121 07716 07716 07716 07716 07716 07716 07716 07716 07716 11236 07716 01121 01121 01121 01121 87034 09182 09182 09182 09182 09182 09182 06751 06486 09182 09182 09182 09182 09182 09182 09182 09182 09182 09182 09182 75915 78189 75915 75915 09182 58474 87575 09182 Stock No RS 0686 6845 0757 0460 0757 1099 0757 0401 0698 5148 0698 3283 0757 0723 0698 4642 0757 0420 0
41. U oca DC Power Supply HP Model 6296A Operating and Service Manual flt HO D ng OPERATING AND SERVICE MANUAL DC POWER SUPPLY HP MODEL 6296A HP Part No 06296 90001 SERIAL NUMBER PREFIX 6D ONE YEAR WARRANTY This HP product has a one year warranty Please replace the first paragraph of the warranty statement on the inside front cover with the following This Hewlett Packard hardware encia against defects in material and workmanship for period of one year from date of delivery HP software and firmware products which are designated by HP for use with a hardware product and when properly amming such defects HP does not warrant that the operation for the software firmware or hardware shall be uninterrupted or error free CALL CE MIRA Wi T mi Wi Dot i CERTIFICATION Hewlett Packard Company certifies that this product met its published specifications at time of shipment from the factory Hewlett Packard 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 Hewlett Packard hardware product is warranted against defects in material and workmanship for a period of one year from date of delivery HP software and firmware products which are designated by HP for use wi
42. WARDS BOTTOM OF Boarp ALL TRANSISTOR BASES FACE TOWARDS THE RIGHT OF BoAzD EXCEPT OTHEE WISE NOTED APPENDIX A Option 11 Overvoltage Protection Crowbar DESCRIPTION This option is installed in DC Power Supplies 6282A 6285A 6286A 6290A 6291A and 6296A and tested at the factory It consists of a printed circuit board screwdriver type front panel potentiometer and six wires that are soldered to the main power supply board The crowbar monitors the output voltage of the power supply and fires an SCR that effectively shorts the output when it exceeds the preset trip voltage The trip voltage is determined by the setting of the CROWBAR ADJUST control on the front panel The trip voltage range is as follows Trip Voltage Range 1 13V zea za 5 42V 5 42V 6 66V To prevent transients from falsely tripping the crowbar the trip voltage must be set higher than the power supply output voltage by the following margin 7 of the output voltage 1V The margin represents the minimum crowbar trip setting for a given output voltage the trip voltage can always be set higher than this margin OPERATION 1 Turn the CROWBAR ADJUST fully clockwise to set the trip voltage to maximum 2 Set the power supply VOLTAGE control for the desired crowbar trip voltage To prevent false crowbar tripping the trip voltage should exceed the desired output voltage by the following amount 7 of the output voltage 41V 3 Slowly turn the
43. ce the output current will exceed the maximum rating of the power supply if the switch contacts open during the switching interval CAUTION If the programming terminals Al and A7 should open at any time during this mode the output cur rent will rise to a value that may damage the power supply and or the load To avoid this possibility connect a 1K resistor 1 5K for Models 6290A and 6296A across the programming terminals Like the programming resistor this resistor should be of the low noise low temperature coefficient type 3 28 Voltage ramming Figure 3 6 In this mode the output current will vary linearly with changes in the programming voltage The pro gramming voltage should not exceed 1 5 volts Voltage in excess of 1 5 volts will result in ex cessive power dissipation in the instrument and possible damage S A3 AS AS AG A EEEEEEEEEEEEEER E i VOLTAGE a SOURCE Figure 3 6 Remote Voltage Programming Constant Current 3 29 The output current will be the programming voltage divided by the internal current sampling resistance R800 The current required from the voltage source will be less than 10 microamperes The impedance matching resistor Rx should be approximately 1000 ohms if the temperature coeffi cient and stability specifications of the power supply are to be maintained 3 30 REMOTE SENSING See Figure 3 7 3 31 Remote sensing is used to maintain good regulation at the load and
44. check the transient recovery time proceed as follows a Connect test setup shown in Figure 5 7 b Turn CURRENT controls fully clockwise c Set METER switch to highest current range and turn on supply d Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output current or S amperes whichever is smaller e Close line switch on repetitive load switch setup 5 5 POWER SUPPLY UNDER TEST OSCILLOSCOPE bh 130A CONTACT PROTECTION NETWORK lute la 5w 200Y wort 3 THIS DRAWING SHOWS A SUGGESTED METHOD i OF BUILDING A LOAD SWITCH HOWEVER l OTHER METHODS COULD 115v BE USED SUCH ASA TRANSISTOR SWITCHING NETWORK MAXIMUM LOAD RATINGS OF LOAD SWITCH ARE S AMPS SOOV 250W NOT 2509w 2 USE MERCURY RELAY CLARE TYPE HGP 1002 OR W E TYPE 2768 3 USE WIRE WOUND RESISTOR Figure 5 7 Transient Response Test Setup f Adjust 25K potentiometer until a stable display is obtained on oscilloscope Waveform should be within the tolerances shown in Figure 5 8 output should return to within 15 mV of original value in less than 50 microseconds prio i EEN UNLOADING TRANSIENT LOADING TRANSIENT Figure 5 8 Transient Response Waveforms 20 Output Impedance To check the output im pedance proceed as follows a Connect test setup shown in Figure 5 9 VOLTMETER 9 4038 INDICATES E VOLTMETER i 403 8 INDICATES E
45. combining straps as shown in Figure 2 2 b Remove four screws from front panel of unit c Slide combining strips between front panel and case of unit d Bolt angle brackets to front sides of case and replace front panel screws 2 15 INPUT POWER REQUIREMENTS 2 16 This power supply may be operated from either a nominal 115 volt or 230 volt 50 60 cycle power source The unit as shipped from the fac tory is wired for 115 volt operation only A factory modification Option 18 must be made to permit operation from a 230 volt line The input power required when operated from a 115 volt 60 cycle power source at full load 1s given in the specification table in Section I 2 17 50 Hz OPERATION 2 18 Theunit as normelly shipped from the factory can be operated from either a 50 or 60 H2 source However with a 50 Hz input the operation of the unit may become somewhat degraded when the temperature exceeds 350 Centigrade instead of the normal 50 Centigrade capability with a 60 Hz input To permit optimum operation at 50 Hz the unit must 2 2 be realigned This realignment procedure is de scribed in Paragraph 5 54 at the rear of the manual 2 19 POWER CABLE 2 20 To protect operating personnel the National Electrical Manufacturers Association NEMA recommends that the instrument panel and cabinet be grounded This instrument is equipped with a three conductor power cable The third conductor is the ground conductor and w
46. detected in the constant voltage constant current input cir Cuit amplified by the gating and error amplifiers and applied to the series regulator in the correct phase and amplitude to counteract the changes 4 6 The fault input circuit detects the presence of overvoltage or overcurrent conditions and gen erates the necessary turn down signals to the SCR control circuit or the series regulator circuit In the case of an overvoltage condition a tuzn down signal is applied to the SCR control circuit The series regulator receives a turn down signal via the gating circuit if an overcurrent condition is detected 4 7 The reference circuit provides stable refer ence voltages which are used by the constant voltage current input circuits for comparison pur poses The bias supply furnishes voltages which are used throughout the instrument for biasing purposes The meter circuit provides an indica tion of output voltage or current in one of two ranges 4 8 SIMPLIFIED SCHEMATIC 4 9 A simplified schematic of the power supply is shown in Figure 4 2 It shows the operating controls the ON off pushbutton the voltage pro gramming controls R813 and R814 and the current programming controls R809 and R810 The METER switch included in the meter circuit block on Figure 4 2 allows the meter to read output voltage or current in one of two ranges Figure 4 2 also shows the internal sources of bias and reference voltages and their nominal
47. e and fall time Resistive Value See Paragraph 5 14 Power supply load resistors Loads and Figure 5 4 5 250 watts Current Value See Figure 5 4 Measure current calibrate Sampling 1 amp 200 watts 20ppm meter Resistor 4 Terminal 1Kn 11 2 watt non inductive Measure impedance Calibrate programming current 100 ohms 5 10 watt Value See Paragraph 5 45 0 1 20 watt Resistor Recommended Model 3420 See Note 403 B 140 A plus 1400A plug in amp 200 CD amp 412A See Figure 5 7 Required Recommended Characteristics Model Resistor Value See Paragraph 5 47 Calibrate programming current 20 1 1 2 watt Decade Range 0 500K Measure programming Resistance Accuracy 0 1 plus 1 ohm coefficients Box Make before break contacts NOTE A satisfactory substitute for a differential voltmeter is to arrange a reference voltage source and nuli detector as shown in Figure 5 3 The reference voltage source is adjusted so that the voltage differ ence between the supply being measured and the reference voltage will have the required resolution for the measurement being made The voltage differ ence will be a function of the null detector that is used Examples of satisfactory null detectors are amp 419 A null detector a DC coupled oscilloscope utilizing differential input or a S0 mv meter move ment with a 100 division scale Por the latter a 2 mv change in voltage
48. e controls of one power supply should be set to the desired output voltage the other power supply should be set for a slightly larger output voltage The supply set to the lower output voltage will act as a constant voltage source the supply set to the higher output will act as a constant current source dropping its output voltage until it equals that of the other supply The constant voltage source will deliver only that fraction of its total rated output current which is necessary to fulfill the total current demand Al AM G S A3 A4 AS AG A7 AB n ALm ALO CJ J uiu upv waw Yu CAPUA fA f AR ava aOOHBOOadaagupdau2r A 5 A G S A3 M AS AG A7 AS Figure 3 10 Normal Parallel Connections 3 4 Auto Parallel The strapping patterns for Auto parallel operation of two power supplies are shown in Figure 3 11 Auto Parallel operation permits equal current sharing under all load con ditions and allows complete control of output current from one master power supply The output current of each slave will be approximately equal Al S5 A2 a o G S A A AS AG A7 AB O m ext wiw aw TE BSE CIE Figure 3 11 Auto Parallel Two Units to the master s regardless of the load conditions Because the output current controls of each slave are operative they should be set to maximum to avoid having the slave revert to constant current operation this would occur if the master output
49. ed to Step 3 Low output voltage Open strap A4 AS R813 R814 C801 Proceed to Step 5 More negative than OV Voltage between S and A4 Table 5 4 Low Output Voltage Troubleshooting Continued Less positive than a Q100B open 0 9V Q100A shorted Q802 or Q801 shorted 0 9V to 1 5V Proceed to Step 6 Voltage between S and 21 OV or positive Q303 shorted Q302 shorted R310 shorted Table 5 5 Preregulator Control Circuit Troubleshooting Probable Cause Waveform between 4 and 3 of a Normal firing pulse CR502 CR504 defective T700 R501 R502 open CRS01 CRS03 T800 defective No or abnormal fir T700 open ing pulse CR500 shorted Proceed to Step 2 Waveform between 90 and 47 Zero or small posi Q700 shorted tive voltage C703 shorted Q701 open R703 primary T700 open Proceed to Step 3 16 to 20 Volt level Q700 open R703 shorted Q701 shorted Proceed to Step 3 Waveform distorted Proceed to Step 3 Waveform between 90 and 9 Amplitude incorrect Q702 defective R707 R708 R713 incor rect value or open C700 CR710 C711 defec tive Period incorrect CR709 defective Proceed to Step 4 Waveform between 90 and 52 Amplitude incorrect CR708 CR709 R702 de fective Period incorrect CR700 through CR703 defective Waveform between 90 and 54 Amplitude incorrect R700 R701 C701 defec tive Period incorrect CR704 through CR707 de fective 5 9 Table 5 6 Common Troubles
50. egulator Overvoltage trip point R604 Q700 Q701 Voltage across R711 Q851 Q852 EM Meter zero Voltmeter R870 RB65 Q853 Meter amplifiers Ammeter tracking R855 Short output ensure that output goes to zero without damage to series pU wee Overcurrent detectors Q801 Q802 C00 ee CR101 Limiting diodes diodes CV load CV load regulation C Voltage across each R403 CR404 Forward bias regulator dida 0 8 0 0 9 Volts GNE w CR700 CR703 Rectifier bridge i aa between 52 IE Waveform between 54 CR704 CR707 Rectifier bridge an 9b Dn 9e ween EM Excessive heat or pressure can lift the copper strip from the board Avoid damage by using a low power soldering iron 50 watts maximum and following these instructions Copper that lifts off the board should be cemented in place with a quick drying acetate base cement having good electrical insulating properties A break in the copper should be repaired by soldering a short length of tinned copper wire across the break Use only high quality rosin core solder when repairing etched circuit boards NEVER USE PASTE FLUX After soldering clean off any excess flux and coat the repaired area with a high quality electrical varnish or lacquer When replacing components with multiple mounting pins suchastube sockets electrolytic capa citors and potentiometers it will be necessary to lift each
51. ent cur rent limiting feature which protects the meter movement against overloads For example if METER switch S2 is placed in the low current range when the power supply is actually deliver ing a higher ampere output the differential am plifiers are quickly driven into saturation limit ing the current through the meter to a safe value SECTION V MAINTENANCE S 1 INTRODUCTION 5 2 Upon receipt of the power supply the per formance check Paragraph 5 10 should be made This check is suitable for incoming inspection If afault is detected inthe power supply while making the performance check or during normal operation proceed to the troubleshooting procedures Para graph 5 41 After troubleshooting andrepair Para graph 5 46 perform any necessary adjustments and calibrations Paragraph 5 48 Before returning the power supply to normal operation repeat the performance check to ensure that the fault has been properly corrected and that no other faults exist Before doing any maintenance checks turn on pow er supply allow a half hour warm up and read the general information regarding measurement tech niques Paragraph 5 3 GENERAL MEASUREMENT TECHNIQUES 5 4 The measuring device must be connected across the sensing leads of the supply or as close tothe output terminals as possible when measuring the output impedance transient response regula tion or ripple of the power supply in order to achieve valid measurements
52. es Paragraph 5 33 5 31 Reference Circuit a Make an ohmmeter check to be certain that neither the positive nor negative out put termi nal is grounded b Turn front panel VOLTAGE and CURRENT controls fully clockwise maximum C Turnon power supply no load connected d Proceed as instructed in Table 5 2 5 32 Series Regulator and Preregulator Feedback Circuits Generally malfunction of these two feed back circuits is indicated by high or lew or no output voltage If one of these situations occur disconnect the load and proceed as instructed in Table 5 3 or 5 4 Preregulator waveforms are in cluded on the schematic at the rear of the manual 5 33 Common Troubles Table 5 6 lists the symptoms checks and probable causes for com mon troubles 5 34 REPAIR AND REPLACEMENT 5 35 Before servicing a printed wiring board refer to Figure 5 10 Section VI of this manual contains a list of replaceable parts Before replacing a semiconductor device refer to Table 5 7 which lists the special characteristics of selected semi conductors If the device to be replaced is not listed in Table 5 7 the standard manufacturers part number listed in Section VI is applicable After replacing a semiconductor device refer to Table 5 8 for checks and adjustments that may be necessary Table 5 2 Reference Circuit Troubleshooting Meter Meter Normal METEN 9 4 10 4Vdc Check 15 4 volt bias or VR600 15 4 40 SVdc
53. fxd film 0 22pf 80V 1 192P2249R8 Sprague 56289 0160 2453 1 C302 301 303 fxd film 0 0022pf 200V 3 192P22292 Sprague 56289 0160 0154 1 C500 fxd elect 10 000uf 75V 1 D39062 HLAB 09182 0180 1924 1 C501 fxd paper 0 1uf 400V 1 160P10494 Sprague 56289 0160 0013 1 C600 fxd elect 325pf 35V 1 D34656 HLAB 09182 0180 0332 1 C601 602 702 801 fxd elect 5uf 65V 4 D33689 HLAB 09182 0180 1836 1 C700 fxd elect luf 35V 1 150D105X9035A2 Sprague 56289 0180 0291 1 C701 fxd elect luf 50V 1 30D105G050BA4 Sprague 56289 0180 0108 1 C703 fxd film 0 1uf 200V 1 192P10492 Sprague 56289 0160 0168 1 C800 fxd elect 1500uf 40V 1 D38733 HLAB 09182 0180 1894 1 C802 fxd elect 10uf 100V 1 30D106G100DC2M1 Sprague 56289 0180 0091 1 C803 fxd elect 1600pf 70V 1 D41655 HLAB 09182 0180 1895 1 C804 NOT ASSIGNED C805 fxd elect 4 7uf 35V 1 150D475X9035B2 Sprague 56289 0180 0100 1 C900 fxd elect 20uf 50V 1 30D206G050DC4 Sprague 56289 0180 0049 1 CR100 102 200 300 301 500 700 711 802 807 808 900 901 Si diode 200ma 200prv 24 HLAB 09182 1901 0033 9 CR400 501 503 809 Si rect 3A 75 C 200prv 4 MR1032B Motorola 04713 1901 0416 4 CR401 403 404 600 601 800 801 902 SL rect S00ma 200prv 8 1N3253 R C A 02735 1901 0389 6 CR402 602 803 804 805 806 Si diode 200ma 15prv 6 HLAB 09182 1901 0461 6 CR502 504 SCR 8 amp 200prv 2 2N3669 R C A 02735 1884 0019 2 Fl Fuse cartridge SA 1 312005 Littlefuse 75915 2110 0010 5 Q100 200 Si NPN diff am
54. gized 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 This instrument is equipped with a line filter to reduce electromagnetic interference EMI and must be connected to a properly grounded receptacle to minimize EMI FUSES Fuses are contained inside the unit and are not user replaceable Only trained service personnel should replace blown fuses and only after identifying and correcting the problem which caused the fuse s to blow DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammabie gases or fumes KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers Component replacement and internal adj stments must be made by qualified service personnel Do not replace components with the power cable connected Under certain conditions dangerous voltages may exist even 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 Operation at line voltages or frequencies in excess of those stated on the data plate may cause leakage curre
55. gulator SCR control circuit series regulator error amplifiers gating circuit a constant volt age input circuit a constant current input circuit a fault input circuit a reference circuit bias supply and a meter circuit 4 3 The input line voltage is reduced to the proper level by the power transformer and coupled to a rectifier bridge consisting of two rectifier diodes and two SCR s The bridge simultaneously performs the necessary rectifying and preregulat ing functions The SCR s operating in conjunc tion with a control circuit minimize the power dissipated by the series regulator by keeping the voltage drop across the regulator at a low and constant level The SCR control circuit accom Overall Block Diagram plishes this by issuing a firing pulse to one of the SCR s once during each half cycle of the input ac The control circuit continuously samples the out put voltage the input line voltage and the volt age across the series regulator and on the basis of these inputs determines at what time during each half cycle that the firing pulse will be gen erated 4 4 The series regulator part of another feed back loop is made to alter its conduction to main tain a constant output voltage or current Its con duction varies in accordance with feedback control signals obtained from the error amplifier It should be noted that the series regulator provides fine and fast regulation of the output while the preregulato
56. h the gating and error amplifiers The error voltage changes the conduction of the series regulator which in turn alters the output voltage R800A 6 6 2V 1 4V US 9 4V cuo R107 2101 R100 C303 TO CR102 GATING R805 CIRCUIT PULLOUT R506 15 4V RESISTOR R103 Hoi Q AS R10 6 R108 Q100A Q100B o 4 CR100 O A 26 2V R105 R8E14 aw US cso 6 2V Figure 4 6 Constant Voltage Input Circuit Simplified Schematic 4 5 so that the difference between the two input volt ages applied to the differential amplifier is re duced to zero This action maintains the output voltage constant 4 24 Stage Q100A of the differential amplifier is connected to a common S potential through im pedance equalizing resistor R106 Resistors R102 and R108 are used to zero bias the input stage offsetting minor base to emitter voltage differ ences in Q100 The base of Q100B is connected to a summing point A4 at the junction of the pro gramming resistors and the current pullout resis tor R805 Instantaneous changes in the output due to load variations or changes due to the manipulation of R813 result in an increase or decrease in the summing point potential Q100B is then made to conduct more or less in accord ance with summing point voltage change The change in Q100B s conduction also varies the conduction of Q100A due to the coupling effects of the common emitter resistor R105 The error voltage is taken from the collector of Q100A and
57. hange locations of Qu01 and CR809 at bottom left of drawing Electrical connections remain the same CHANGE 3 _ The serial number prefix of the instrument has been changed from 6D to 7D e the parts list and on the schematic make e following changes Add new resistor 402 600 ohm 5 W HP P N 0811 1860 across R309 150 ohm Change T801 to HP P N 9100 2184 On the schematic the primary of bias trans former 1801 should be connected as shown in the following sketch for 115 Vac operation For 230 Vac operation the jumpers between lugs 1 and 3 and 2 and 4 must be removed and lugs 2 and 3 connected together In ad dition a new power transformer T800 must be installed in accordance with Option 18 4 H Tao Change R601 to 422 onm CHANGE 4 Make the following changes in the parts list Add new diode CR603 1N485B HP P N 1901 0033 Change R313 to 1k 5 selected 1 2 W HP P N 0686 1025 Change R707 to 2 W I R C Type BWH HP P N 0811 1674 1 4 W HP P N 0698 4590 Change R870 to 5 k pot HP P N 2100 1824 Change R871 to 750 ohm 1 HP P N 0757 0420 Delete R872 Add new Zener diode VR800 4 22 V HP P N 1902 3070 On the schematic delete R872 in the meter circuit and connect VR800 in its place The anode of VR800 goes to base of Q850 and cathode goes to 15 4 V reference Also connect CR603 across VR600 in the reference circuit The anode of CR603 goes to S and the cathode goes to
58. he part number is listed except in instruments containing many sub modular assemblies in which case the TQ appears the first time the part number is listed in each assembly d Manufacturer s Part Number or Type e Manufacturer s Federal Supply Code Num ber Refer to Table 6 3 for manufacturer s name and address f Hewlett Packard Part Number g Recommended Spare Parts Quantity RS for complete maintenance of one instrument during one year of isolated service h Parts not identified by a reference desig nator are listed at the end of Table 6 4 under Me chanical and or Miscellaneous The former consists of parts belonging to and grouped by individual as semblies the latter consists of all parts not im mediately associated with an assembly 6 3 ORDERING INFORMATION 6 4 To order a replacement part address order or inquiry to your local Hewlett Packard sales office see lists at rear of this manual for addresses Specify the following information for each part Model complete serial number and any Option or special modification J numbers of the instrument Hewlett Packard part number circuit reference des ignator and description To order a part not listed in Table 6 4 give a complete description of the part its function and its location Table 6 1 Reference Designators miscellaneous electronic part fuse jack jumper relay inductor meter assembly blower fan capacitor circuit breaker diode de
59. he strapping patterns shown in Figures 3 3 through 3 6 employ local sensing note that it is possible to operate a power supply simultaneously in the remote sensing and Constant Voltage Constant Current remote programming modes 3 35 SERIES OPERATION 3 36 Normal Series Connections Figure 3 8 Two or more power supplies can be operated in series to obtain a higher voltage than that avail able from a single supply When this connection Al 8 AZ 7 B A3 A4 AS AG A7 AB Figure 3 8 Normal Series Connections is used the output voltage is the sum of the voltages of the individual supplies Each of the individual supplies must be adjusted in order to Obtain the total output voltage The power supply contains a protective diode connected internally across the output which protects the supply if one power supply is turned off while its series part ner s is on 3 37 Auto Series Connections Figure 3 9 The Auto Series configuration is used when it is de sirable to have the output voltage of each of the series connected supplies vary in accordance with the setting of a control unit The control unit is called the master the controlled units are called slaves At maximum output voltage the voltage of the slaves 1s determined by the setting of the front panel VOLTAGE control on the master Th master supply must be the most positive supply the series The output CURRENT controls of all series units are operative and the curre
60. hen the cable is plugged into an appropriate receptacle the in strument is grounded The offset pin on the power cable three prong connector is the ground connec tion 2 21 To preserve the protection feature when op erating the instrument from a two contact outlet use a three prong to two prong adapter and con nect the green lead on the adapter to ground 2 22 REPACKAGING FOR SHIPMENT 2 23 To insure safe shipment of the instrument it is recommended that the package designed for the instrument be used The original packaging material is reusable If it is not available con tact your local Hewlett Packard field office o Obtain the materials This office will also furnish the address of the nearest service office to which the instrument can be shipped Be sure to attach a tag to the instrument which specifies the own er model number full serial number and service required or a brief description of the trouble SECTION 111 OPERATING INSTRUCTIONS 3 1 OPERATING CONTROLS AND INDICATORS 3 2 The front panel controls and indicators to gether with the normal turn on sequence are shown in Figure 3 1 pg CA AAIS OMS 5 POWLA JUPPLY V PATA Le BT Puss Cufor vo tant TURN ON SEQUENCE 1 PUSH ON OFF BUTTON AND BUTTON SHOULD LIGHT 2 SET METER SWITCH TO DESIRED VOLTAGE RANGE 3 ADJUST COARSE AND FINE VOLTAGE CONTROLS UNTIL DESIRED OUTPUT VOLTAGE IS INDICATED ON METER 4 SET METER SWITCH DESIRED CUR
61. her a constant voltage or a constant current output using the front panel controls local programming no strapping changes are necessary A3 A4 AS A6 A AB EIE ES POINTS Figure 3 2 Normal Strapping Pattern 3 7 CONSTANT VOLTAGE 3 8 To select a constant voltage output proceed as follows a Turn on power supply and adjust VOLTAGE controls for desired output voltage out put terminals open b Short output terminals and adjust CUR RENT controls for maximum output current allow able current limit as determined by load condi tions If a load change causes the current limit to be exceeded the power supply will automatically Crossover to constant current output at the preset current limit and the output voltage will drop pro portionately In setting the current limit allow ance must be made for high peak current which can cause unwanted cross over Refer to Paragraph 3 46 3 9 CONSTANT CURRENT 3 10 To select a constant current output pro ceed as follows a Short output terminals and adjust CUR RENT controls for desired output current b Open output terminals and adjust VOLTAGE controls for maximum output voltage al lowable voltage limit as determined by load conditions If a load change causes the voltage l mit to be exceeded the power supply will auto matically crossover to constant voltage output at the preset voltage limit and the output current will drop proportionately In setting
62. ia Electric Products Inc Electronic Tube Div Receiving Tube Operations Emporium Pa MANUFACTURER ADDRESS Grant Pulley and Hardware Co West Nyack N Y Burroughs Corp Electronic Components Div Plainfield N J U S Radium Corp Morristown N J Yardeny Laboratories Inc New York N Y Arco Electronics Inc Great Neck N Y TRW Capacitor Div Ocallala Neb RCA Corp Electronic Components Harrison N J Rummel Fibre Co Newark N J Marco amp Oak Industries a Div of Oak Electro netics Corp Anaheim Calif Philco Corp Lansdale Div Lansdale Pa Stockwell Rubber Co Inc Philadelphia Pa Tower Olschan Corp Bridgeport Conn Cutler Hammer Inc Power Distribution and Control Div Lincoln Plant Lincoln 111 Litton Precision Products Inc USECO Div Litton Industries Van Nuys Calif Gulton Industries Inc Metuchen N J United Car Inc Chicago Ill Miller Dial and Nameplate Co El Monte Calif Radio Materials Co Chicago Ill Augat Inc Attleboro Mass Dale Electronics Inc Columbus Neb Elco Corp Willow Grove Pa Honeywell Inc Div Micro Switch Freeport Il Whitso Inc Schiller Pk Iil Sylvania Electric Prod Inc Semi conductor Prod Div Woburn Mass Essex Wire Corp Stemco Controls Div Mansfield Ohio Raytheon Co Components Div Ind Components Oper Quincy Mass Wagner Electric Corp Tung Sol Div Livingston N J Southco Inc Lester Pa Leecraft Mfg Co I
63. in oo POWER SUPPLY UNDER TEST OSCILLATOR 200 CD Figure 5 9 Output Impedance Test Setup b Set METER switch to highest voltage range turn CURRENT controis fully clockwise and turn on supply c Adjust VOLTAGE controls until front panel meter reads 10 volts d Set AMPLITUDE control on Oscillator to 10 volts Ein and FREQUENCY control to 100Hz e Record voltage across output terminals of the power supply Eo as indicated on AC voltmeter f Calculate the output impedance by the following formula _ EgR Zout Ein n Eo Eo rms voltage across power supply output terminals R 1000 Ein 10 volts g The output impedance Zout should be less than 0 001 ohm h Using formula of step f calculate output impedance at frequencies of 1KHz 100KHz and 1MHz Values should be less than 0 01 ohm 0 2 ohm and 2ohms respectively 5 21 CONSTANT CURRENT TESTS 5 22 Load Regulation To check the constant cur rent load regulation proceed as follows a Connect test setup shown in Figure 5 4 b Turn VOLTAGE controls fully clockwise c Set METER switch to highest current range and turn on supply d Adjust CURRENT controls until front panel meter reads exactly the maximum rated output cur rent e Read and record voltage indicated on dif ferential voltmeter 5 6 Short out load resistor Ry by closing switch Sl g Reading on differential voltmeter should not vary from reading recorded in s
64. in 15 mv following a current change in the output equal to the current rating of the supply or 5 amperes whichever is smaller OVERLOAD PROTECTION A continuously acting constant current cir cuit protects the power supply for all overloads Specifications including a direct short placed across the termi nals in constant voltage operation The constant voltage circuit limits the output voltage in the constant current mode of operation METER The front panel meter can be used as either a 0 70 or 0 7 volt voltmeter or as a 0 4 or 0 0 4 amp ammeter OUTPUT CONTROLS Coarse and fine voltage controls and coarse and fine current controls provide continuous ad justment over the entire output span OUTPUT TERMINALS Three five way output posts are provided on the front panel and an output terminal strip is located on the rear of the chassis All power supply output terminals are isolated from the chassis and either the positive or negative termi nal may be connected to the chassis through a separate ground terminal If the front panel ter minals are used the load regulation will be 0 S5mV per ampere greater due to the front terminal re sistance ERROR SENSING Error sensing is normally accomplished at the front terminals if the load is attached td the front or at the rear terminals if the load 1s attach ed to the rear terminals Also provision is in cluded on the rear terminal strip for remote sens ing REMOTE PR
65. ing in its linear region The cathodes of the OR gate diodes are always at a more positive potential than the satu ation potential of Q300 or Q301 Thus the diode associated with the saturated transistor is reverse biased while the diode associated with the other transistor is forward biased In the constant volt age mode Q301 1s operating in its linear region and Q300 is saturated due to the positive collector voltage of Q200B OR gate diode CR301 is there fore reverse biased while OR gate diode CR300 is forward biased coupling the constant voltage feedback signal to the error amplifier Opposite conditions prevail during constant current opera tion 4 33 Capacitor C302 is a commutating capacitor which improves the transient response of the unit Resistor R300 is the biasing resistor for the OR gate diodes 4 34 ERROR AMPLIFIERS 4 35 The error amplifiers Q302 and Q303 ampli fy the feedback signal from the constant voltage or constant current input circuit to a level suffi cient to drive the series regulator transistor Transistor Q303 serves as the driver and Q302 the predriver for the series regulator The RC net work composed of C301 and R307 is an equaliz ing network which provides for high frequency roll off in the loop gain response n order to stabilize the feedback loop 4 36 Capacitor C900 diode CR901 and resistor R902 form a long time constant network which achieves a slow tum on characteristic When the u
66. ip Resistor value to be as follows Model 6282A 6285A 6286A 6290A 6291A 6296A Res 2K 4K 4K 8K 8K 18K b Disconnect jumper between A3 and A4 on rear terminal barrier strip C Connect a decade resistance in place of R806 d Connect a differential voltmeter between S and S and turn on supply e Adjust decade resistance box so that dif ferential voltmeter indicates maximum rated output voltage within the following tolerances Model 6282A 6285A 6286A 6290A 6291A 6296A Tol Vdc 20 2 0 4 40 4 0 8 0 8 21 2 f Replace decade resistance with resistor of appropriate value in R806 position 5 46 CONSTANT CURRENT PROGRAMMING CURRENT 5 47 To calibrate the constant current programming current proceed as follows a Connect power supply as showninFig 5 4 b Remove strap between A6 and A7 leaving A7 and A8 jumpered c Connect a 0 1 1 2 watt resistor be tween Al and A7 Resistor value is lKa 1 SKn for Models 6290A and 6296A d Connect decade resistance box in place of R808 e Set METER switch to highest current range and turn on supply f Adjust the decade resistance so that the differential voltmeter indicates 1 0 0 02Vdc g Replace decade resistance with appro priate value resistor in R808 position 5 48 OVERVOLTAGE TRIP 5 49 To adjust the overvoltage trip point proceed as follows a Connect differential voltmeter across S and S terminals of supply b Rotate VOLTAGE controls fully clockw
67. ise c Turn on unit Differential voltmeter should read 20 above maximum rated output volt age within 25 d If it does not turn off supply and connect decade resistance across R605 in place of R604 e Adjust decade resistance until differential voltmeter reads that indicated in step C NOTE The 15 4V reference voltage must be kept within 0 SVdc when ad justing the decade resistance box f Replace decade resistance with resistor of appropriate val ue in R604 position 5 50 TRANSIENT RECOVERY TIME 5 51 To adjust the transient response proceed E o follows a Connect test setup as shown in Figure 5 7 b Repeat steps a through e as outlined in Paragraph 5 19 c Adjust R307 so that the transient response is as shown in Figure 5 8 5 52 PREREGULATOR TRACKING 60Hz OPERATION 5 53 To adjust the preregulator control circuit with a 60Hz ac input proceed as follows Connect proper load resistor across out put terminals of supply Resistance value to be as follows Model Res 6282A 6285A 6286A 6290A 6291A 6296A ln an 2a 13a Ba 20a b Connect DC voltmeter between TP27 and TP90 across series regulator C Turn on supply and adjust VOLTAGE con trols for maximum rated output voltage d Adjust R711 so that DC voltmeter reads 3 0 2Vdc 5 54 PREREGULATOR TRACKING 50H2 OPERATION 5 55 To adjust the preregul ator control circuit when the ac input is from a 50Hz source proceed as e follows a
68. location by means of an external voltage source or resistance b Remote Sensing The degradation in regulation which would occur at the load because of the voltage drop in theload leads can be reduced by using the power supply in the remote sensing mode of oper ation 1 1 C Series and Auto Series Operation Power supplies may be used in series when higher output voltage is required in the voltage mode of operation or when greater voltage compliance is required in the constant current mode of operation Auto Series operation permits one knob control of the total output voltage from a master supply d Parallel and Auto Parallel Operation The power supply may be operated in parallel with similar unit when greater output current capability is required Auto Parallel op eration permits one knob control of the total out put current from a master supply e Auto Tracking The power supply may be used as a master supply having control over one or more slave supplies that furnish various voltages for a system 1 6 SPECIFICATIONS 1 7 Detailed specifications for the power supply are given in Table 1 1 1 8 OPTIONS 1 9 Options are factory modifications of a standard instrument that are requested by the customer The following options are available for the instrument covered by this manual Where necessary detailed coverage of the options is included throughout the manual Option No Description
69. magnitudes with an input of 115 Vac and no load connected Diode CR809 connected across the output termi nals of the power supply is a protective device which prevents internal damage that might occur if a reverse voltage were applied across the output terminals Output capacitor C809 stabilizes the feedback loop when the normal strapping pattern shown in Figure 4 2 is employed Note that this capacitor can be removed if an increase in the programming speed is desired Under these con ditions capacitor C802 serves to insure loop stability Resistors R811 and R812 limit the out put of the supply if the straps between the output and sensing terminals are inadvertently opened 4 10 DETAILED CIRCUIT ANALYSIS 4 11 PREREGULATOR AND CONTROL CIRCUIT 4 12 The preregulator minimizes changes in the power dissipated by the series regulator due to output voltage or input line voltage changes Preregulation is accomplished by means of a phase control circuit utilizing SCR s CR504 and CR502 as the switching elements The appropriate SCR is fired once during each half cycle 8 33 millisec onds of the rectified ac see Figure 4 3 Notice that when the SCR is fired at an early point during the half cycle the de level applied to the series regulator is fairly high When the SCR is fired later during the cycle the de level is relatively low 60H2 AC INPUT 1e 8 JMS l I d LARGE OC A Di LEVEL SA d t l 1 X Puy i FIRING t
70. nc LIC N Y Methode Mfg Co Rolling Meadows IIL Switchcraft Inc Chicago Ill Bendix Corp Microwave Metals and Controls Inc Control Devices Div Franklin Ind Products Group Attleboro Mass Weckesser Co Inc Chicago Ill Research Products Corp Madison Wis Amphenol Corp Amphenol Rotron Inc Woodstock N Y Controls Div Janesville Wis Vector Electronic Co Glendale Calif Industrial Retaining Ring Co Carr Fastener Co Cambridge Mass Irvington N J Victory Engineering Corp Springfield N J Bendix Corp Electric Power Div Eatontown N J Herman H Smith Inc Brooklyn N Y Central Screw Co Chicago Ill Gavitt Wire and Cable Div of Amerace Esna Corp Brookfield Mass IMC Magnetics Corp Eastern Div Westbury N Y Sealectro Corp Mamaroneck N Y ETC Inc Cleveland Ohio International Electronic Research Corp Burbank Calif Renbrandt Inc Boston Mass e n Reference Mfr Part M fr Designator Description Quantity or Type Mfr Code Stock No RS C100 fxd film 0 082uf 200V 1 192P82392 Sprague 56289 0160 0167 1 C200 fxd film 0 0047uf 200V 1 192P47292 Sprague 56289 0160 0157 1 C300
71. nit is first turned on C900 provides a positive voltage to the base of Q302 keeping the series regulator from conducting initially As C900 charges up the restrictive bias becomes less positive enabling the regulator to conduct Diode CR902 provides a low resistance discharge path for C900 when the unit is turned off 4 37 FAULT INPUT CIRCUIT 4 38 The fault input circuit see schematic at rear protects the power supply against overvolt age and overcurrent conditions Transistor Q800 and associated components comprise the over voltage detector With normal output voltages Q800 is cut off due to the 15 4V reference voltage connected to the top of voltage divider RB23 and R821 If the output voltage exceeds a certain limit about 2096 above the maximum rated output voltage transistor Q800 is driven into conduction Current is then conducted away from the summing point and in opposition to the charge path of C700 in the SCR control circuit As a result the SCR s are fired at a later time reducing the series reg ulator input voltage to a safe value 4 39 A full wave rectified voltage obtained from the SCR control circuit excercises a stabilizing influence on transistor Q800 This signal tends to synchronize the conduction of Q800 at a 120 Hz rate preventing random firing of the SCR s 4 40 Transistors Q801 and Q802 provide overcur rent and short circuit protection for the unit Overcurrent protection is accomplished by Q802
72. nt limit is equal to the lowest control setting If any output CURRENT controls are set too low automatic crossover to constant current operation will occur and the output voltage will drop Remote sensing and programming can used however the strapping arrangements shown in the applicable figures show local sensing and programming 3 A4 AS A6 A7 AB elelalalelelelelelelelelalel DICERE LIBB 9 sur AS A6 A AB Figure 3 9 Auto Series Two Units 3 38 In order to maintain the temperature coeffi cient and stability specifications of the power supply the external resistor Rx shown in Figure 3 9 should be stable low noise low temperature coefficient less than 30 ppm per degree Centi grade resistors The value of this resistor is dependant on the maximum voltage rating of the master supply The value of Rx is this voltage divided by the voltage programming current of the slave supply 1 Kp where Kp is the voltage pro gramming coefficient The voltage contribution of the slave is determined by its voltage control set ting 3 39 PARALLEL OPERATION 3 40 Normal Parallel Connections Figure 3 10 Two or more power supplies can be connected in parallel to obtain a total output current greater than that available from one power supply The total output current is the sum of the output cur rents of the individual power supplies The output CURRENT controls of each power supply can be separately set The output voltag
73. nts in excess of 3 5 mA peak SAFETY SYMBOLS Instruction manual symbol the product will IN be marked with this symbol when it is necessary for the user to refer to the instruction manual refer to Table of e or bm indicate earth ground terminal calis attention to a procedure practice or the like which if not correctly performed Contents Indicates hazardous voltages or or adhered to could result in personal The WARNING sign denotes a hazard It injury Do not proceed beyond a Warning WARNING sign until the indicated d conditions are fully understood and met The CAUTION sign denotes a hazard tt CAUTION calis attention to an operating procedure or or the like which if not correctly A performed or adhered to could result in Caution damage to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indicated conditions are fully understood and met DO NOT CIRCUMVENT SAFETY DEVICES AC mains power exists on exposed terminals in various locations in the mainframe and on the load modules To protect the user against the danger of electric shock the unit is equipped with a safety interlock that removes ac mains power when the top cover is removed Do not attempt to defeat the function of the safety interiock DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized
74. one given for 50 Hz operation in paragraph 5 55 steps g through j except that the resistance value should be selected to provide a 3 V 2 V drop across the series regulator For 50 Hz operation the voltage drop across the series regulator remains 3 5 V Center R711 before using the resistance box to determine the value for R712 Also change VR600 to 9 V HP P N 1902 0785 change R606 to 9 k HP P N 698 5454 and change R611 to 490 ohm 3 MW HP P N 0811 1801 CIRCUIT PATENTS APPLIED i FOR LICENSE TO USE MUST i BE OBTAINED IN WRITING FROM HEWLETT PACKARD CO HARRISON DIVISION t NOTES 1 All resistors are in ohms 1 2W 5 uness otherwise noted 2 All capacitors are in microfarads unless otherwise noted CHANGE 20 In the parts list and on the schematic for the overvoltage protection crowbar delete R1 and VR1 add U1 voltage regulator HP P N 1826 0276 and C2 fxd elect 1 uF 50 V HP P N 0180 0230 and change R9 to 1 5 k HP P N 0757 0427 and R10 to 1 5 k 5 HP P N 0811 1805 as shown in the schematic below No Page 6 HP P N 06296 90001 changes continued Oa nanges continued CHANGE 21 In the replaceable parts list change the HP P N s for the binding posts and associated hardware to the following Red binding post qty 2 1510 0091 Terminal lug qty 2 0360 0042 Lockwasher qty 2 2190 0079 Nut qty 2 2500 0001 Black binding post qty 1 1510 0107 Terminal lug
75. p 2 HLAB 09182 1854 0229 2 Q300 301 601 602 603 Si NPN 5 4JX16A1014 G E 03508 1854 0071 5 Q302 700 701 801 802 Si NPN 5 2N 3417 G E 03508 1854 0087 5 Q303 400 Si NPN power 2 HLAB 09182 1854 0225 2 Q401 NOT USED Q600 1 PNP 1 40362 R C A 02735 1853 0041 1 Q702 800 850 852 853 Si PNP 5 2N2907A Sprague 56289 1853 0099 Q851 Si NPN diff amp 1 HLAB 09182 1854 0221 1 Q854 NOT ASSIGNED R100 202 819 fxd met film 160K 1 Vew 3 Type CEA T O LRC 07716 0698 5092 1 R101 201 820 fxd met film 61 9Ka 1 18w 3 Type CEA T O LRC 07716 0757 0460 1 R102 108 204 fxd met film 432Ka 1 V8w 3 Type CEA T O LR C 07716 0757 0480 1 R103 306 815 fxd comp lKa 15 iw 3 EB 1025 A B 01121 0686 1025 1 R104 fxd ww 490a 5 3w 20ppm 1 242E 4915 Sprague 56289 0811 1801 1 R105 206 fxd met film 33 0Kn 1 Y 8w 2 Type CEA T O LR C 07716 0698 5089 1 R106 200 203 fxd met film 1 5Ka 195 1 8w 3 Type CEA T O LR C 07716 0757 0427 1 R107 205 fxd met film 47 5Ka 2196 1 8w 2 Type CEA T O LRC 07716 0757 0457 1 6296A 6 5 Reference Mfr Part Mfr Designator Description Quantity or Type Mfr Code Stock No RS R300 fxd comp 330K4 5 4w R301 fxd comp 394 5 dw R302 303 fxd comp 36Kn 5 3w R304 fxd comp 754 5 4w R305 fxd comp 6 2Ka 25 iw R307 var ww 10Ka R308 fxd comp 3Kn 25 lw R309 fxd comp 1504 596 40w R310 fxd comp 47K 596 4w R311 fxd ww 6 84 15 R312 811 812 fxd
76. p Nela Park Cleveland Ohio General Radio Co West Concord Mass LTV Electrosystems Inc Memcor Com ponents Operations Huntington Ind Dynacool Mfg Co Inc Saugerties N Y National Semiconductor Corp Santa Clara Calif Palo Alto Calif Kenilworth N J Hewlett Packard Co Heyman M g Co IMC Magnetics Corp New Hampshire Div Rochester N H SAE Advance Packaging Inc Santa Ana Calif Ramona Calif Owensboro Ky Chicago Ill Budwig Mfg Co G E Co Tube Dept Lectrohm Inc P R Mallory amp Co Inc Indianapolis Ind Muter Co Chicago Ill New Departure Hyatt Bearings Div General Motors Corp Sandusky Ohio Ohmite Manufacturing Co Skokie Ill Penn Engr and Mfg Corp Doylestown Pa Polaroid Corp Cambridge Mass Raytheon Co Lexington Mass Simpson Electric Co Div of American Gage and Machige Co Chicago Ill Sprague Electric Co North Adams Mass Superior Electric Co Bristol Conn Syntron Div of FMC Corp Homer City Pa Philadelphia Pa New York N Y Thomas and Betts Co Union Carbide Corp Ward Leonard Electric Co Mt Vernon N Y Ke MANUFACTURER ADDRESS Amperite Co Inc Union City N J Beemer Engrg Co Fort Washington Pa Belden Corp Chicago DL Bud Radio Inc Willoughby Ohio Cambridge Thermionic Corp Cambridge Mass Bussmann Mfg Div of McGraw amp Edison Co St Louis Mo CTS Corp Elkhart Ind L T T Cannon Electric inc Los Angeles Calif
77. parts list change Q40 from HP P N 1854 1124 to HP P N 1854 0458 CHANGE 29 In the replaceable parts list change the part number for Q851 from HP P N 1854 0221 to HP P N 1854 0229 CHANGE 30 In the replaceable parts list change Q400 to HP P N 06296 80004 Use this part number for replacement on all units 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 Hewlett Packard Company assumes no liability for the customer s failure to comply with these requirements BEFORE APPLYING POWER Verify that the product is set to match the available line voltage 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 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 firmiy connected to an electrical ground safety ground at the power outlet 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 ener
78. pin Slightly working around the components several times until it is free WARNING If the specific instructions outlinedinthe steps below regarding etched circuit boards without eyelets are not followed extensive damage to the etched circuit board will result 1 Apply heat sparingly to lead af component 2 Reheat solder in vacant eyeletand quic kly tobe replaced If lead of component passes insert a small awl to clean inside of hole through an eyelet a m 1f hole does in the circuit f m not have an CONDUCTOR board apply Ee eyelet in SIDE heat on com sert awl or ponent side a 57 drill of board If k from con lead of com ductor side ponent does of board not pass through an eyelet apply Meat to conductor side of board 4 Hold part against board avoid overheating 3 Bend clean tinned lead on new part and and solder leads carefully insert Apply heat to compo through eyelets or E nent leads on correct holes in board Bide of board as explained m VLL UILLZZLLLLDTTIS Gur in step 1 s In the event that either the circuit board has been damaged orthe conventional method is imprac tical use method shown below Thisis especially applicable for circuit boards without eyelets 1 Clip lead as shown below 2 Bend protruding leads upward Bend lead of new APPLY component SOLDER around pro truding lead Apply solder using a pair of long nose pliers as a heat sink edd PPP PPP Pepper Thi
79. pling resistor If a difference exists the differential amplifier produces an error voltage which is proportional to this difference The remaining components in the feedback loop amplifiers and series regulator function to maintain the drop across the current sampling resistor and consequently the output current at a constant value NIE 60 R808 PULLOUT RESISTOR Q A8 R200 LX A7 O A 2810 T ceos R809 R800A R827 R8005 Q 0UT O S 4 29 Stage Q200A is connected to S through im pedance equalizing resistor R203 Instantaneous changes in output current on the positive line are felt at the current summing point terminal A7 and hence the base of Q200B Stage Q200B varies its conduction in accordance with the polarity of the change at the summing point The error voltage is taken from the collector Q200B and ultimately varies the conduction of the series regulator 4 30 Resistor R304 in conjunction with C300 helps stabilize the feedback loop Resistor R808 shunting the pullout resistor serves as a trimming adjustment for the programming current flowing through R809 and R810 4 31 GATING CIRCUIT 4 32 The gating circuit see schematic consists of gating amplifiers Q301 and Q300 and associated OR gate diodes CR300 and CR301 The gating circuit provides sharp crossover between constant voltage and constant current operation During steady state conditions one transistor is saturat ed while the other is conduct
80. r the programming voltage source should be approx imately 1000 ohms to maintain the temperature and stability specifications of the power supply 3 24 REMOTE PROGRAMMING CONSTANT CUR RENT 3 25 Either a resistance or a voltage source can be used to control the constant current output of the supply The CURRENT controls on the front panel are disabled according to the following pro cedures Al Ss A2 A3 A4 AS AG A7 PROGRAMMING RESISTOR Remote Resistance Programming Constant Current Figure 3 5 3 26 Resistance rammin igure 3 5 th s mode the output current varies at a rate determined by the programming coefficient 100 ohms per ampere for Models 6282A and 6286A 200 ohms per ampere for Models 6285A and 6291A and 500 ohms per ampere for Models 6290A and 6296A The programming coefficient is determined by the Constant Current programming current 1 mA for Models 6282A 628SA 6286A and 6291A or 0 66 mA for Models 6290A and 6296A This current is adjusted to within 10 at the factory If greater programming accuracy is required it may be achieved by changing resistor R808 as outlined in Section V 3 27 Use stable low noise low temperature co efficient less than 30 ppm 0Cc programming re sistors to maintain the power supply temperature coefficient and stability specifications A switch may be used to set discrete values of output cur rent A make before break type of switch should be used sin
81. r handles large relatively slow regu lation demands The dc current from the series regulator passes through a current sampling re sistor before reaching the positive output terminal 15 4V 9 4V 6 2V 6 24 R807 AB A VOLTS CURAENT NOTE 2 INPUT CIRCUIT A6 Q200 PINE current Z REO AD COARSE CURRENT Rene ADJ Al 29 2827 3 SCR R503 casos oa 9502 50 L ana 4 Di Tem 9 10 Q700 Q701 Q702 NOTES 1 VOLTAGE ACROSS C800 FOR EACH MODEL IS SHOWN BELOW MODEL NO 6282A 6205A 285A 62904 6291A 6296A VOLTS DC 16 2 38 2 16 2 21 2 162 21 2 2 POSITIVE BIAS VOLTAGE TOR EACH MODEL IS SHOWN BELOW 23 MODEL NO 6282A 628SA 6286A 6290A 6291A 6296A VOLTS DO in d ISV 20V d 20V 3 VOLTAGE ACROSS INPUT FILTER CAPACITOR FOR EACH MODEL IS SHOWN BELOW MODEL NO 6282A 6285A 6286A 6290A 6291A 6295A VOLTS DC 15 25 24 45 45 s Figure 4 2 Simplified Schematic 4 5 The feedback signals that control the con duction of the series regulator are originated with in the constant voltage input circuit or the con stant current input circuit The output voltage of the power supply is sampled by the constant volt age input circuit by means of the sensing termi nals S The voltage developed across the cur rent sampling resistor is the input to the constant current input circuit This voltage drop varies in direct proportion to the output current Any changes in output voltage current are
82. r misuse operation outside of the environmental specifications for the product or improper site preparation and maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFCALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER S SOLE AND EXLCUSIVE REMEDIES HP 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 Hewlett Packard Sales and Service office for further information on HP s full line of Support Programs Make all corrections MANUAL CHANGES Model 62964 DC Power Supply Manual HP Part No 06296 90001 Change Date 10 03 90 in the manual according to errata below then check the following table for your power supply serial number and enter any listed change s in the manual we ew IA A me UA A as RA AAA A AAA e e HG SERIAL 00231 00260 00261 00290 00291 00320 00321 00350 00351 00380 00381 00410 00411 00522 00523 00612 00613 00712 00713 01776 01777 01796 01797 01816 01817 02411 02412 02419 02420 02776 02777 02956 02957 02986 02987 03146 03147 03386 03387 03545 03547 0408
83. r shielded wires and each load separate ly connected to the remote distribution terminals For this case remote sensing should be used Paragraph 3 30 3 14 OPERATION OF SUPPLY BEYOND RATED OUTPUT 3 15 The shaded area on the front panel meter face indicates the amount of output voltage or current that is available in excess of the normal output Although the supply can be operated in this shaded region without being damaged it can not be guaranteed to meet all of its performance specifications However if the line voltage is maintained above 115 Vac the supply wilhproba bly operate within its specifications 3 16 OPTIONAL OPERATING MODES 3 17 REMOTE PROGRAMMING CONSTANT VOLT AGE 3 18 The constant voltage output of the power supply can be programmed controlled from a remote location if required Either a resistance or voltage source can be used for the programming device The wires connecting the programming terminals of the supply to the remote programming device should be twisted or shielded to reduce noise pick up The VOLTAGE controls on the front panel are disabled according to the following procedures PROGRAMMING RESISTOR Figure 3 3 Remote Resistance Programming Constant Voltage 3 19 Resistance Programming Figure 3 3 In this mode the output voltage will vary at a rate determined by the programming coefficient 200 ohms per volt 300 ohms per volt for Model 6296A The output voltage will increa
84. reduce the degradation of regulation which would occur due to the voltage drop n the leads between the power supply and the load Remote sensing is accomplished by utilizing the strapping pattern shown in Figure 3 7 The power supply should be turned off before changing strapping patterns It is not required that these leads be as heavy as the load leads However they must be twisted or shielded to minimize noise pick up A3 A4 AS AS A AS Figure 3 7 Remote Sensing CAUTION Observe polarity when connecting the sensing leads to the load 3 32 Note that it is desirable to minimize the drop in the load leads and it is recommended that the drop not exceed 1 volt per lead if the power supply is to meet its DC specifications If a larger drop must be tolerated please consult a Hewlett Packard field representative NOTE Due to the voltage drop in the load leads it may be necessary to re adjust the current limit in the remote sensing mode 3 33 The procedure just described will result in a low DC output impedance at the load If a low AC impedance is required it is recommended that the following precautions be taken a Disconnect output capacitor C803 by disconnecting the strap between A2 and S b Connect a capacitor having similar char acteristics approximately same capacitance same voltage rating or greater and having good high frequency characteristics across the load using short leads 3 34 Although t
85. replaced by a new option Option 028 In the replaceable parts list remove R903 HP P N 0686 1245 aty 1 Option 028 modifies the standard 115 V unit to a 230 V unit as described below To con vert the supply for 230 V operation a Remove the jumpers from between terminals terminals 1 and 3 and 2 and 4 of T800 b Install a jumper between terminals 2 and 3 of T800 l C Replace F1 with a 3A 250 V fuse 2100 0003 Bage 5 HP P N 06296 90001 changes continued 4 Note Due to the circuit changes shown on the next figure it is no longer necessary sia change any jumper connections at T801 dual primary windings of T801 are per nently wired in parallel across winding 3 4 of T800 The pilot light in series with R903 is also connected across this winding CHANGE 16 In the parts list and on che schematic change R307 to 10 k 10 HP P N 2100 3210 CHANGE 17 the parts list and on the schematic add capacitor C901 0 1 uF 250 V HP P N 0160 4065 as shown below MO ndn F1 acord CHANGE 18 In the parts list and on the schematic add resistor R904 10 ohm 5 1 2 W HP P N 0686 1005 in series with the negative lead of capacitor C801 CHANGE 19 the replaceable parts list and on the atic indicate that 12 k is the nominal value for R712 The value for R712 is fac tory selected to optimize the range of ramp adjust pot R711 CHANGE 19 Cont Tne procedure for selecting R712 is identi cal to the
86. ries 8400 Include s Series 8400 RD 411 Includes Series 8400 RD 411 6296A 6 8 Mfr Mfr ode HLAB 09182 HLAB 09182 HLAB 09182 Beldon 70903 Heyco 28520 Reliance 08530 Reliance 08530 Sprague 56289 Reliance 08530 Tinnerman 89032 Whitehead 79307 Whitehead 79307 HLAB 09182 HLAB 09182 Penn Eng 46384 Penn Eng 46384 Cinch 71785 HLAB 09182 I R C 07716 I R C 07716 I R C 07716 I R C 07716 LR C 07716 I R C 07716 I R C 07716 I R C 07716 Stock No RS 0370 0101 0370 0179 0360 1234 8120 0050 0400 0013 0340 0174 2190 0710 0180 1973 2190 0708 1400 0332 1400 0330 0340 0169 0340 0171 0590 0395 0590 0393 0360 1143 1440 0042 2100 1867 2100 2029 2100 1867 2100 2029 2100 1867 1140 0020 2100 2029 1140 0020 E AA 6 33MS TEST POINT 53 TEST POINT 4 C TEST POINT 59 hi cyt 7 oe ol are 8 33MS D TEST POINT 56 E TEST POINT 47 F TEST POINTS 46 45 v E 8 33 G TEST POINT 2 NOTES 1 ALL WAVEPORMS TAKEN WITH 115VAC 60Hz SINGLE PHASE INPUT AT MAXIMUM RATED OUTPUT VOLTAGE AND NO LOAD CONNECTED AMPLITUDES ARE TYPICAL 10x 2 OSCILLOSCOPE DC COUPLED AND REFERENCED TO T P 90 UNLESS OTHERWISE INDICATED 3 WAVEFORMS ARE NOT DRAWN TO SCALE 4 AMPLITUDE OF WAVEFORM AT T P 47 VARIES WITH DIFFERENT MODELS AS FOLLOWS MODELNO 6282A 6285A 6286A 62904 6291A 62964 VOLTAGE 15V 17v ISV 20V y 20V Eeer IK w
87. rs Inc Lawndale Calif ADDRESS Westinghouse Electric Corp Electronic Tube Div Elmira N Y Fairchild Camera and Instrument Corp Semiconductor Div Mountain View Calif Birtcher Corp The Los Angeles Calif Sylvania Electric Prod Inc Sylvania Electronic Systems Western Div Mountain View Calif IRC Div of TRW Inc Burlington Plant Burlington lowa Texas Instruments Inc Semiconductor Components Div Dallas Texas RCL Electronics Inc Manchester N H Amerock Corp Rockford Ill Sparta Mfg Co Dover Ohio Ferroxcube Corp Saugerties N Y Fenwal Laboratories Morton Grove TL Amphenol Corp Broadview Ill Radio Corp of America Solid State and Receiving Tube Div Somerville N Je G E Semiconductor Products Dept Syracuse N Y Eldema Corp Compton Calif Transitron Electronic Corp Wakefield Mass Pyrofilm Resistor Co Inc Cedar Knolls N J Arrow Hart and Hegeman Electric Co Hartford Conn ADC Electronics Inc Harbor City Calif Caddell amp Bums Mfg Co Inc Mineola N Y Hewlett Packard Co Palo Alto Div Palo Alto Calif Motorola Semiconductor Prod Inc Phoenix Arizona Westinghouse Electric Corp Semiconductor Dept Youngwood Pa Ultronix Inc Grand Junction Colo Wakefield Engr Inc Wakefield Mass General Elect Co Electronic Capacitor amp Battery Dept Irmo S C Bassik Div Stewart Wamer Corp Bridgeport Conn
88. s 30843 OM RC a 3 S o e 0 copy H d A 3 ON MODELS 62824 G2854A G28GA AND G2931A CR 400 CR50I CR503 AND CR8O3 eoo 0 MOUNTED ON HEAT SINKS nad PRINTED CIRCUIT BOARD 4 ON MODELS G290A AND GIGA CR400 CRSOL CR503 CREO ARE MOUNTED ON PRINTED CIRCUIT BOARD NOT HEAT SINKS O t E S 1 gt o Va o Y ya dd a M ot Sa KH v yo E Oy 2 Sg 99 Ian a ul 23 W 8 260 OOD qe ew EF orc ao als 0a 2 5 4a Za awl Oy Fax u Qa 3v9 wt 3 30 tao qh Eur zi Di 5 ON MODELS 62854 62904 G29 A AND G236A R401 AND 401 OO 15 REPLASED WITH A JUMPER ARE NOT USED AND R4 9 5 00000006 006 6000 D e zine E 9 019 9 350779 9 31557 9 CR400 o E gue ete CEA Cice etti o c ace 101 Imm Oy 2 EE SEN Sec 509 ertore 1088 e 02 O eure 2 S 9098 e 3079 i EB e DU eS EP GRD C 9 8 9 2 2 2 8 este S ez eee ns 818 e110679 SC EE i DEM we 90tu SS D anu Sa re 074 NOTE ARE NOT USED AND R400 15 REPLASED WITH A JUMPER MOUNTED ON PRINTED CIRCUIT BOARD NOT HEAT SINKS 5 ON MODELS 6285A 6290A GZ9 A AND G29GA R40 AND Q 401 MOUNTED ON HEAT SINKS NOT PRINTED CIRCUIT BOARD A ON MODELS 62824 C2 85A GZ8GA AND G231A CR 400 CR50I CR503 AND CR803 4 ON MODELS G 40A AND G29GA CR400 CR50I CR503 CREOF ARE O D I CATHODES OF ALL DIODES FACE TO
89. s procedure is used in the field only as an alternate means of repair It is not used within the factory Figure 5 10 Servicing Printed Wiring Boards Table 5 8 CR600 CR601 CR800 CR801 CR501 CR504 VR600 VR601 Reference voltages Checks and Adjustments After Replacement of Semiconductor Devices Continued Rectifier diodes Voltage across appro priate filter capacitor Check 9 4V and 6 2V reference voltages Table 5 9 Calibration Adjustment Summary Adjustment or Calibration Meter Zero Voltmeter Tracking Ammeter Tracking Voltage Programming Current Current Programming Current Overvoltage Trip Transient Response Preregulator Tracking 5 36 ADJUSTMENT AND CALIBRATION 5 37 Adjustment and calibration may be required after performance testing troubleshooting or repair and replacement Perform only those adjustments that affect the operation of the faulty circuit and no others Table 5 9 summarizes the adjustments and calibrations contained in the following paragraphs 5 38 METER ZERO 5 39 Proceed as follows to zero meter a Turn off instrument after it has reached normal operating temperature and allow 30 seconds for all capacitors to discharge b Insert sharp pointed object pen point or awl into the small indentation near top of round black plastic disc located directly below meter face c Rotate plastic disc clockwise cw until meter reads zero then rota
90. scope ground one ter minal of the power supply and then ground the case of the oscilloscope to this same po nt Make cer tain that the case is not also grounded by some other means Power line Connect both oscillo scope input leads tothe power supply ground termi S 1 nal and check that the oscilloscope is not exhibi ting aripple or transient due to ground loops pick up or other means 5 8 TEST EQUIPMENT REQUIRED 5 9 Table S 1 lists the test equipment required to perform the various procedures described in this Section Table S 1 Test Equipment Required Required Type Characteristics Measure DC voltages calibration procedures Differential Voltmeter Sensitivity 1 mv full scale min Input impedance 10 megohms min Range 90 130 volts Vary AC input Equipped with voltmeter accurate within 1 volt Variable Voltage Transformer AC Voltmeter Oscilloscope DC Voltmeter Measure AC voltages and ripple Accuracy 2 Sensitivity 1 mv full scale deflection min Display transient response waveforms Sensitivity 100 uv cm Differential input Range 5Hz to 1 MHz Impedance checks Accuracy 2 Measure DC voltages Accuracy 1 Input resistance 20 000 ohms volt min Repetitive Rate 60 400 Hz 2usec Measure transient response Load Switch tis
91. se 1 volt for each 200 ohms or 300 ohms added in series with the programming terminals The programming coeffi cient is determined by the programming current This current is factory adjusted to within 2 of S ma 2 of 3 3 ma for Model 6296A If greater programming accuracy 1s required it may be achieved by changing resistor R806 3 20 The output voltage of the power supply should be zero volts 20 millivolts when zero ohms is connected across the programming termi nals 3 21 To maintain the stability and temperature Coefficient of the power supply use programming resistors that have stable low noise and low temperature less than 30 ppm per degree Centi grade characteristics A switch can be used in conjunction with various resistance values in order to obtain discrete output voltages The switch Should have make before break contacts to avoid momentarily opening the programming terminals during the switching interval 3 22 Voltage Programming Figure 3 4 Employ the strapping pattern shown on Figure 3 4 for voltage programming In this mode the Output voltage will vary ina 1 to 1 ratio with the pro gramming voltage reference voltage and the load on the programming voltage source will not exceed 25 microamperes s A3 A AS A6 A7 elglelelelelalgle hc VOLTAGE SOURCE elglalelelelel Figure 3 4 Remote Voltage Programming Constant Voltage 3 23 The impedance matching resistors Rx fo
92. sville N Y Fenwal Elect Framingham Mass Coming Glass Works Electronic Components Div Raleigh N C IRC Div of TRW Inc Semiconductor Plant Lynn Mass Amatom Electronic Hardware Co Inc New Rochelle N Y Beede Electrical Instrument Co Penacook N H General Devices Co Inc Indianapolis Ind Semcor Div Components Inc Phoenix Arizona Robinson Nugent Inc New Albany Ind Torrington Mfg Co West Div Van Nuys Calif Transistor Electronics Corp Minneapolis Minn Use Code 28480 assigned to Hewlett Packard Co Palo Alto California 6 2 Table 6 3 Code List of Manufacturers Continued C MANUFACTURER ADDRESS Delco Radio Div of General Motors Corp Kokomo Ind Atlantic Semiconductors Inc Asbury Park N J Fairchild Camera and Instrument Corp Semiconductor Div Transducer Plant Mountain View Calif Daven Div Thomas A Edison Industries McGraw Edison Co Orange N J Signetics Corp Sunnyvale Calif Bendix Corp The Navigation and Control Div Teterboro N J Electra Midland Corp Mineral Wells Texas Fansteel Metallurgical Corp No Chicago Ill Union Carbide Corp Electronics Div Mountain View Calif UID Electronics Corp Hollywood Fla Pamotor Inc Pampa Texas General Electric Co Schenectady N Y General Electric Co Lamp Div of Con sumer Prod Grou
93. t at rear of manual for ad dresses Part No Description 14515A Rack Kit for mounting one 51 high supply Refer to Section II for details 14525A Rack Kit for mounting two 4 high supplies for details 1 12 INSTRUMENT IDENTIFICATION Refer to Section II 1 13 Hewlett Packard power supplies are identi fied by a three part serial number tag The first part is the power supply model number The sec ond part is the serial number prefix which con sists of a number letter combination that denotes the date of a significant design change ber designates the year and the letter A through M The num designates the month January through December respectively serial number The third part is the power supply 1 14 If the serial number prefix on your power supply does not agree with the prefix on the title page of this manual change sheets are included to update the manual Where applicable back dating information is given in an appendix at the rear of the manual 1 15 ORDERING ADDITIONAL MANUALS 1 16 One manual is shipped with each power supply Additional manuals may be purchased from your local Hewlett Packard field office see list at rear of this manual for addresses the model number serial number prefix stock number provided on the title page Specify and Table 1 1 INPUT 105 125 VAC single phase 50 60Hz 4 SA 250W OUTPUT 0 60 volts 0 3
94. t is permitted to fire the SCR s Diode CR902 provides a discharge path for C900 when the unit 1s turned off 4 19 SERIES REGULATOR 4 20 The series regulator transistor Q400 or Q400 and Q401 see schematic at rear of manual serves as the series or pass element which provides precise and rapid control of the output The conduction of the series transistor s is con trolled by the feedback signals obtained from driver Q303 Diode CR400 connected across the regulator circuit protects the series element s from reverse voltages that could develop across them during parallel operation 1f one supply is turned on before the other 4 21 CONSTANT VOLTAGE INPUT CIRCUIT See Figure 4 6 4 22 The circuit consists of the programming re sistors R813 and R814 and a differential amplifier stage Q100 and associated components Tran sistor Q100 consists of two silicon transistors housed in a single package The transistors have matched characteristics minimizing differential voltages due to mismatched stages Moreover drift due to thermal differentials is minimized since both transistors operate at essentially the same temperature 4 23 The constant voltage input circuit continu ously compares a fixed reference voltage with a portion of the output voltage and if a difference exists produces an error voltage whose amplitude and phase is proportional to the difference The error output is fed back to the series regulator throug
95. te ccw slightly in order to free adjustment screw from meter suspension If pointer moves repeat steps b and c 5 40 VOLTMETER TRACKING 5 41 To calibrate voltmeter tracking proceed as follows Pointer Paragraph R870 and R865 R855 R806 R808 R604 R307 R711 a To electrically zero meter set METER switch to highest current position and with supply off and no load connected adjust R870 until front panel meter reads zero b Connect differential voltmeter across sup ply observing correct polarity c Set METER switch to highest voltage range and turn on supply Adjust VOLTAGE contro until differential voltmeter reads exactly the maximum rated output voltage d Adjust R865 until front panel meter also indicates maximum rated output voltage S 42 AMMETER TRACKING 5 43 To calibrate ammeter tracking proceed as follows 8 Zero meter as described in step a of 5 41 Connect test setup shown on Figure 5 4 leaving switch S1 open b Turn VOLTAGE control fully clockwise and set METER switch to highest current range c Turn on supply and adjust CURRENT con trols until differential voltmeter reads 1 0Vdc d Adjust R855 until front panel meter indi cates exactly the maximum rated output current 5 44 CONSTANT VOLTAGE PROGRAMMING CURRENT 5 45 To calibrate the constant voltage programming current proceed as follows a Connect a 0 1 20 watt resistor between terminals S and A4 on rear barrier str
96. tep e by more than the following variations expressed in mVdc e Model 6282A 6285A 6286A 6290A 6291A 6296A Variation 0 60 2 20 20 60 40 830 0 70 0830 5 23 Line Regulation To check the line regula tion proceed as follows amp Utilize test setup shown in Figure 5 4 leaving switch S1 open throughout test b Connect variable auto transformer between input power source and power supply power input C Adjust auto transformer for 10SVAC input d Turn VOLTAGE controls fully clockwise e Set METER switch to highest current range and turn on supply Adjust CURRENT controls until front panel meter reads exactly the maximum rated output cur rent g Read and record voltage indicated on dif ferential voltmeter h Adjust variable auto transformer for 125 VAC input i Reading on differential voltmeter should not vary from reading recorded in step g by more than the following variations expressed in mVdc Model 6282A 6285A 6286A 6290A 6291A 6296A Variation 060 2220 060 0830 070 0830 5 24 Ripple and Noise To check the ripple and e noise proceed as follows a Use test setup shown in Figure 5 4 ex cept connect AC voltmeter across sampling resistor instead of differential voltmeter b Rotate VOLTAGE controls fully clockwise c Set METER switch to highest current range and turn on supply d Adjust CURRENT controls until front panel meter indicates exactly the maximum rated output current
97. th CURRENT_INPUT REFERENCE tol 2100 1832 Ce one D D REGA 36 5X Koo IT D E ES R607 eoe y 560 rote FL I eee Lose 2 IK Q 808 SHUNT hu If D EST tese sns DY Ae ckaoo 9 RAID 14 y ceoo i500 am 4ov gb ear LIA E AA O AI GBK 7 e gt gt BE r on TBoo 9 00 646 soy 2 5 al SPARE vip laa PE roo iBox GATING Ge W CG Pt 7801 Jem wore VOLTAGES WERE MEASURED UNDIR THE FOLLOWING CONDITIONS u z 2 LL EESISTORS Ate W 57 UNLESS NOTED OTHER WISE 1 BIMFSON MODEL 269 OR EQUIVALENT 3 OENOTES 20 PPM WIRE TEMP COEFF 2 115VAC INPUT 4 REAL TERMINALS SHOWN IN NORMAL STRAPPING TO 8 UNLESS OTHERWISE INDICATED 1 1 WE EEN 310 UNLESS OTHERWISE INDICATED 5 REF VOLTAGES MEASUEED AT UGV LINE NO LOAD S ALL READINGS TAKEN WITH SUPPLY IN CONSTANT VOLTAGE OPERATION q DENOTES CURRENT SIGNAL DENOTES VOLTAGE SIGNAL d AT MAXIMUM RATED OUTPUT WITH NO LOAD CONNECTED CURRENT 7 T OEN TES MoruAL VALUE SLECTED AT FACTOEY Fol OPTimum PEEFOEMMNCE Model 6296A Schematic Diagram i CONTROLS SHOULD BE TURNED FULLY CLOCKWISE amp amp OO G9 001 69 65 89 Dei 6 6 8 85 OOG Lucy t e3 3090 e eMe odo 201 959 eiie eue rte ec e e eine lt eiie 7063 siumo o OTS e t0ue Hoogu t o acy otis Po IEN e
98. th 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 period of 90 days from date of delivery During the warranty period HP Company will at its option either repair or replace products which prove to be defective HP 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 HP Customer shall prepay shipping charges by and shall pay all duty and taxes for products returned to HP for warranty service Except for products returned to Customer from another country HP shall pay for return of products to Customer Warranty services outside the country of initial purchase are included in HP s product price only if Customer pays HP interna tional prices defined as destination local currency price or U S or Geneva Export price If HP is unable within a reasonable time to repair or replace any product to a condition as warranted the Customer shall be entitled to a refund of the purchase price upon return of the product to HP 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 o
99. tup shown in Figure 5 4 leaving switch S1 open b Turn CURRENT controls fully clockwise c Set METER switch to highest current range and turn on supply d Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated out put current Differential voltmeter should read 1 0 e 0 02 Vdc POWER SUPPLY UNDER TEST RESISTOR CURRENT SAMPLING RESISTOR Figure 5 4 Output Current Test Setup 5 16 Load Regulation To check constant voltage load regulation proceed as follows Connect test setup as shown in Figure 5 5 b Turn CURRENT controls fully clockwise C Set METER switch to highest current range and turn on supply a POWER SUPPLY UNDER TEST OO GA OO OO CO rorsossosos 4 O N L Deny yr M ww e E DIFFERENTIAL VOLTMETER Figure 5 5 Load Regulation Constant Voltage d Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage e Read and record voltage indicated on differential voltmeter f Disconnect load resistors g Reading on differential voltmeter should not vary from reading recorded in step e by more than the following variations expressed in mVdc Model 6282A 6285A 6286A 6290A 6291A 6296A Variation 2 3 3 5 5 7 NOTE If measurements are made at the front terminals readings will be 0 5mV per amp greater due to front terminal re sistance 5 17 Line Reg
100. ulation To check the line regula tion proceed as follows a Connect variable auto transformer between input power source and power supply power input b Turn CURRENT controls fully clockwise C Connect test setup shown in Figure 5 5 d Adjust variable auto transformer for 105 VAC input e Set METER switch to highest voltage range and turn on supply f Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage g Read and record voltage indicated on dif ferential voltmeter h Adjust variable auto transformer for 125 VAC input i Reading on differential voltmeter should not vary from reading recorded in step g by more than the following variations expressed in mVdc Model 6282A 6285A 6286A 6290A 6291A 6296A Variation 2 3 3 5 25 7 5 18 Ripple and Noise To check the ripple and noise proceed as follows a Retain test setup used for previous line regulation test except connect AC voltmeter across output terminals as shown in Figure 5 6 b Adjust variable auto transformer for 125 VAC input c Set METER switch to highest current range d Turn CURRENT controls fully clockwise and adjust VOLTAGE controls until front pane meter indicates exactly the maximum rated output voltage e AC voltmeter should read less than 0 SOmVrms POWER SUPPLY LOAD RESISTORS AC VOLTMETER Figure 5 6 Ripple and Noise Constant Voltage S 19 Transient Recovery Time To
101. ulse Loading 3 6 Output Capacitance 3 6 Reverse Voltage Loading 3 6 Reverse Current Loading 3 6 PRINCIPLES OF OPERATION 4 1 Overall Block Diagram Discussion 4 1 Section Page No IV PRINCIPLES OF OPERATION 4 8 Simplified Schematic 4 3 4 10 Detailed Circuit Analysis 4 3 4 11 Preregulator and Control Circuit 4 3 4 19 Series Regulator 4 5 4 21 Constant Voltage Input Circuit 4 5 4 26 Constant Current Input Circuit 4 6 4 31 Gating Circuit 4 7 4 34 Error Amplifiers 4 7 4 37 Fault Input Circuit 4 7 4 42 Reference Circuit 4 8 4 46 Meter Circuit 4 8 V MAINTENANCE 5 1 5 1 Introduction 5 1 5 3 General Measurement Techniques 5 1 5 8 Test Equipment Required 5 1 5 10 Performance Test 5 3 5 12 Constant Voltage Tests 5 4 5 21 Constant Current Tests 5 6 5 25 Troubleshooting 5 6 5 27 Trouble Analysis 5 7 5 34 Repair and Replacement 5 7 5 36 Adjustment and Calibration 5 13 5 38 Meter Zero 5 13 5 40 Voltmeter Tracking 5 13 5 42 Ammeter Tracking 5 13 5 44 Constant Voltage Programming Current 5 14 5 46 Constant Current Programming Current 5 14 5 48 Overvoltage Trip 5 14 5 50 Transient Recovery Time 5 14 5 52 Preregulator Tracking 60 Hz Operation 5 14 5 54 Preregulator Tracking 50 Hz Operation 5 14 VI REPLACEABLE PARTS 6 1 6 1 Introduction 6 1 6 4 Ordering Information 6 1 Reference Designators Abbreviations Manufacturers 6 8 Code List of Manufacturers 6 2 11 Parts List Table SECTION 1 GENERAL INFORMATION 1 1 DESCRIPTION 1
102. vice signal ing lamp 6 1 Table 6 1 plug transistor resistor switch transformer terminal block thermal switch Reference Designators Continued vacuum tube neon bulb photocell etc zener diode socket integrated cir cuit or network Table 6 2 Description Abbreviations ampere alternating current assembly board bracket degree Centigrade card coefficient composition cathode ray tube center tapped direct current double pole double throw double pole single throw electrolytic encapsulated farad degree Farenheit fixed germanium Henry Hertz integrated circuit incandescent kilo 103 milli 10 3 mega 106 micro 1076 metal inside diameter u n m mg g dg manufacturer modular or modified mounting nano 107 normally closed normally open nickel plated ohm order by description outside diameter pico 10712 printed circuit potentiometer peak to peak parts per million peak reverse voltage rectifier root mean square silicon single pole double throw single pole single throw small signal slow blow tantulum titanium volt variable wirewound Watt Table 6 3 Code List of Manufacturers Ed MANUFACTURER ADDRESS 00629 EBY Sales Co Inc Jamaica N Y Aerovox Corp New Bedford Mass Sangamo Electric Co S Carolina Div Pickens S C Allen Bradley Co Milwaukee Wis Litton Industries Inc Beverly Hills Calif TRW Semiconducto
103. voltage positions the voltage across divider R850 R851 and R852 connected across the output of the sup ply is the input to the differential amplifier When 2 is in one of the current positions the voltage across divider R853 R854 and R855 con nected across the sampling resistor is the input to the differential amplifier With S2 in the higher voltage range position 2 the voltage drop across R852 is applied to stage Q851A while stage Q851B is grounded tothe S terminal For low out put voltages S2 can be set to position 1 result ing in the appl cation of a larger percentage of the output voltage drop across R851 and R852 to stage Q8S1A With S2 in the higher current posi tion 3 the voltage drop across R853 1s applied 4 9 to stage Q851B while stage Q851A is grounded to the S terminal In the low current range the voltage drop across R853 and R854 is applied to Q851B 4 49 Differential amplifier stage Q851 is a stable device having a fixed gain of ten To minimize temperature effects the two stages are housed in a single package that is similar to those used in the constant voltage and current in put circuits The outputs of the differential am plifier drive meter amplifiers Q852 and Q853 which in turn deflect the meter Transistor Q850 provides a constant bias current to the emit ters of Q852 and Q853 Potentiometer R870 per mits electrical zeroing of the meter 4 50 The meter circuit contains an inher
104. will result in a meter deflec tion of four divisions CAUTION Care must be exercised when using an electronic null detector in which one input terminal is grounded to avoid ground loops and circulating currents POWER SUPPLY UNDER TEST S 10 PERFORMANCE TEST S 11 The following test can be used as n in coming inspection check and appropriate portions of the test can be repeated either to check the operation of the instrument after repairs or for periodic maintenance tests The tests are per formed using a 115 VAC 60 cps single phase in put power source If the correct result is not ob tained for a particular check do not adjust any Red proceed to troubleshooting Paragraph 5 28 Figure 5 3 Differential Voltmeter Substitute Test Setup 5 3 5 12 CONSTANT VOLTAGE TESTS 5 13 Rated Output and Meter Accuracy 5 14 Voltage Proceed as follows a Connect toad resistor across rear output terminals of supply Resistor value to be as follows Model 6282A 6285A 6286A 6290A 6291A 6296A Res la 4 la L n 8 20 b Connect differential voltmeter across S and S terminals of supply observing correct polar ity c Set METER switch to highest voltage range and turn on supply d Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage e Differential voltmeter should indicate maximum rated output voltage within 29 5 15 Current Proceed as follows a Connect test se

DC Power Supply HP Model 6296A Operating and Service Manual

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