Home

HP 6260B User's Manual

Contents

1. OUTPUT VOLTAGE UNLOADING TRANSIENT Figure 5 5 Load Transient Recovery Time Waveforms 531 Temperature Coefficient Definition The change in output voltage per degree Celsius change in the ambient temperature measured while ac line voltage output voltage setting and load resistance are al held constant 5 32 The temperature coefficient of a power supply is measured by placing the power supply in an oven and varying it over any temperature span within its rating Most HP power supplies are rated for operation from O to 55 C The power supply temperature must be allowed to stabilize for a sufficient time at each measurement temperature 5 33 The temperature coefficient given in the specifi cations is the maximum temperature dependent output voltage change which will result over any one degree interval The digital voltmeter used to measure the supply s output voltage change should be placed outside the oven and should have a long term stability adequate to insure that its drift will not affect the overall measurement accuracy 5 34 To check the temperature coefficient proceed as follows a Connect load resistance and digital voltmeter as illustrated in Figure 5 1 b Turn CURRENT controls fully clockwise c Turn on supply and adjust front panel VOLTAGE controls until front panel voltmeter indicates maximum rated output voltage d Place power supply in temperature controlied oven 5 6 digital voltm
2. REGULATED DC POWER SUPPLY MODELS 6259B 6260B 6261B 6268B 6269B OPERATING AND SERVICE MANUAL FOR MODEL 6259B SERIALS 1535A 00651 AND ABOVE MODEL 6260B SERIALS 1545A 01026 AND ABOVE MODEL 6261B SERIALS 1543A 00551 AND ABOVE MODEL 6268B SERIALS 1539A 01481 AND ABOVE MODEL 6269B SERIALS 1535A 01631 AND ABOVE For instruments with serial numbers above those listed a change page may be included HP Part No 5950 1766 Printed March 1976 Section TABLE OF CONTENTS Page GENERAL INFORMATION 1 1 11 DESCRIPTION 1 1 1 8 SPECIFICATIONS 1 1 1 10 OPTIONS 1 2 1 12 INSTRUMENT MANUAL IDENTIFICATION 12 1 15 ORDERING ADDITIONAL MANUALS 13 INSTALLATION 2 1 2 1 INITIAL INSPECTION 2 1 23 Mechanical Check 2 1 2 5 Electrical Check 2 1 2 7 INSTALLATION DATA 24 2 9 Location and Cooling 2 1 2 11 Outline Diagram 2 1 2 13 Rack Mounting 2 1 2 15 INPUT POWER REQUIREMENTS 24 2 17 INPUT LINE VOLTAGE OR FREQUENCY CONVERSION 2 2 2 20 Converting a Standard Instrument to 208 Volt Operation Models 6259B 6261B and 6268B 2 2 2 22 Converting a Standard Instrument to 208 Volt Operation Models 6260B and 6269B 2 2 2 24 Converting a Standard Instrument to 115 Volt Operation Models 6259B 6261B and 6268B 2 2 2 26 Convert
3. MAX Figure 3 9 Voltage Programming of Output Current Variable Gain 3 54 Overvoltage Protection in Auto Parallel The interconnections shown in Figures 3 10 and 3 11 between the external crowbar trigger terminals on the master and on the slave s must be made to permit the overvoltage crowbar in the master to fire the SCRs in the master and the slave s if an overvoltage condition occurs Be sure to connect them with correct polarity plus to plus and minus to minus Set the slave supply overvoltage potentiometer s to maximum clockwise to disable them and adjust the overvoltage trip point at the master supply 3 55 Auto Parallel With Remote Sensing To combine auto parallel operation with remote sensing connect the supplies as described above but remove the S and S jumpers from the master supply and connect the S and S terminals directly to the and ends of the load Observe the precautions outlined under paragraph 3 27 3 56 Auto Parallel With Remote Programming When two or three supplies are connected in auto parallel their combined output voltage current or both can also be remotely programmed Refer to the appropriate sections of paragraph 3 34 for the additional rear panel connections required and make these connections to the master supply only Observe all precautions outlined in the paragraphs on remote programming The simultaneous use of remote sensing and remote programming is also
4. Disabling the Crowbar REPLACEABLE PARTS CIRCUIT DIAGRAM AND COMPONENT LOCATION DIAGRAMS Page 5 19 SECTION I GENERAL INFORMATION 1 1 DESCRIPTION 1 2 The five constant voltage constant current power supply models included in this manual use a transistor series regulator combined with a triac preregulator for high efficiency excellent regulation and low ripple and noise These supplies are packaged in 7 inch high full rack width cabinets that are suitable for either bench or relay rack operation 1 3 The outputs of these supplies can be varied from zero to full rated voltage or current by setting coarse and fine voltage and current controls on the front panel or they can be programmed remotely by resistance or voltage inputs to rear panel terminals When the voltage controls are used to establish a constant output voltage the current controls establish a current limit that can protect the load from over current When the current controls are used to establish a constant output current the voltage controls establish a voltage limit that can protect the load from excessive voltage The crossover from constant voltage to constant current operation or vice versa occurs automatically when the load current reaches the value established by the current controls or the voltage reaches the value established by the voltage controls The output voltage and current can both be monitored continuously on f
5. Mixer amplifier stabilization diode V R60 VR61 Reference regulator CV transient response Output voltage CC load regulation R47 See para 5 98 6 2 and 6 2V reference voltages Crowbar 5 60 Disassembly Procedures 5 61 The following seven paragraphs describe the procedures for removing and disassembling the five sub assemblies in this supply These procedures are referred to throughout the manual where necessary 5 62 A1 Main Circuit Board Removal remove the main printed circuit board proceed as follows a Disconnect input power and remove top cover from supply b Remove six hold down screws visible on component side of main circuit board c Unplug board from receptacle mounted on inter connection circuit board by gently pulling on finger hole in opposite end of circuit board Only finger hole should be used to remove board do not pull on board mounted components to aid removal Take care that rear barrier strip clears opening in rear panel 5 63 A5 Front Panel Removal To remove the front panel proceed as follows a Disconnect input power turn supply upside down and remove four screws holding handles to front panel b The front panel may now be swung outward hinging on wires to circuit breaker Access is provided to all panel mounted components 5 64 Main Filter Capacitor Bank Removal To remove the main filter capacitors C101 through C103 C104 or C10
6. 7 1 INTERCONNECTION BOARD TB2 Af BOARD A4 HEATSINK ASS Y SEE FIG 7 2 SEE FIG 7 7 16 7 5 amp 7 6 FOR COMPLETE ASSEMBLY A3ul IN MODEL 62698 ABCIIO CII2 MOUNTED ON 5 5081 ASCBI 58121 ASM ASRI 2 ASRI23 5 2 ASRI24 ASRI25 Figure 7 3 Chassis Component Locations Top View A2 RFI ASSEMBLY SEE FIG 7 1 FOR INTERNAL COMPONENTS WARNING Ad HEATSINK ASSEMBLY THE CASE AND HEATSINK OF THE A2 SEE FIG 7 5 8 7 6 FOR RFI ASSEMBLY ARE AT AC LINE POTENTIAL COMPLETE ASSEMBLY EXERCISE EXTREME CAUTION DURING SERVICING cig UNDER A2 ASS Y CONNECTED ACROSS OUTPUT BUS BARS 2 A3C3 AND ASRI20 UNDER A2 ASS Y SEE FIG 7 2 B2 NOT IN MODEL 6259B LARGER TYPE FAN IN MODEL 6269B cios 3 MODEL ONLY C104 MODELS 6260B 626 B ONLY Figure 7 4 Chassis Component Locations Bottom View 7 2 A4CRIIO 4010 43005 440106 4959104 AGCRIO MODEL 62608 A 7 MODEL 62608 ONLY Jo en A4CRIOI 40107 MODELS A4QIOB MODELS A4CRIOS 626
7. DER 097 RM eR RIS R13 e HREJ HERE OT T RN ON CONTROL CONTROL _ OVERVOLTAGE PROTECTION CROWBAR PREREGULATOR MIXER amp ERROR AMPLIFIER CURRENT ZERO CURRENT PROG VOLTAGE ZERO Figure 7 7 A1 Board Component Locations 74 WARNING SOME CIRCUITS ON THIS CIRCUIT BOARD ARE CONNECTED DIRECTLY TO THE INPUT AC POWER LINE EXERCISE EXTREME CAUTION WHEN WORKING ON ENERGIZED CIRCUITS THE FIXED AND VARIABLE RESISTORS SHOWN IN THE ZERO ADJUST SECTION OF THE BOARD ARE NOT INCLUDED IN THE STANDARD INSTRUMENT THEY ARE SUPPLIED IN OPTION 020 021 022 AND 040 INSTRU MENTS ONLY 2 RI OMITTED IN OPTION 020 022 AND 040 INSTRUMENTS 3 R21 OMITTED IN OPTION 021 022 AND 040 INSTRUMENTS
8. Zero the output current of Option 040 instruments as follows a Connect test setup shown in Figure 5 7 except omit load resistor R and connect just current sampling resistor Rg across the output of the supply b Connect remote programming setup shown in Figure 3 7 and adjust remote resistance to zero Rotate VOLTAGE controls fully clockwise and turn on supply d If reading on digital voltmeter is not exactly zero volts adjust potentiometer R119 labeled CURRENT ZERO and accessible through hole in rear panel until reading is zero volts 2mV 5 96 Constant Current Programming Accuracy Standard Instrument To calibrate the constant current programming current of a standard instrument proceed 5 19 as follows a Connect test setup shown in Figure 5 7 b Disconnect strap between terminals and on rear barrier strip Connect 0 1 1 8 watt resistor of value shown below between terminals A4 and on rear barrier strip Model Value 6259B 2000 6260B 20022 6261B 20022 6268B 1802 6269B 2002 d Connect decade resistance box in place of R30 mount ed on standoffs on main circuit board see Figure 7 7 e Rotate VOLTAGE controls fully clockwise and turn on supply f Adjust decade resistance box until digital voltmeter indicates exactly 0 5Vdc 9 Replace decade resistance box with fixed composi tion 596 1 2 watt resistor of same value 5 97 Constant Current Programming Accuracy O
9. resistance Rc to be set to any desired value from 0 to If R is greater than Rc the supply is in constant voltage operation If RI is less than Rc the supply is in constant current operation 4 11 The short circuit protection circuit see Figure 4 1 protects the series regulator if the supply s output is shorted while its controls are set to a high output voltage and current The protection circuit monitors the voltage drop across the series regulator If this voltage rises above a preset level the protection circuit limits the current through the series regulator until the preregulator can reduce the voltage across the series regulator Once this voltage returns to normal the short circuit protection circuit is turned off and has no further effect on the operation of the supply 4 12 The overvoltage protection crowbar monitors the output of the supply and fires an SCR which short circuits the supply if its output exceeds a preset threshold The crowbar also sends a turn down signal to the preregulator control circuit 4 13 The overvoltage limit circuit protects the main rectifier diodes and filter capacitors from damage if the series regulator transistors short or the voltage programming control opens The circuit monitors the output voltage of the supply and sends a turn down signa to the preregulator contro circuit if the voltage exceeds approximately 120 of its rated maximum OPEN CIRCUIT _ CONSTANT VOLTAGE LOAD
10. Code List of Manufacturers CODE MANUFACTURER ADDRESS IRC Div of TRW Inc Philadelphia Pa Howard B Jones Div of Cinch Mfg Corp New York N Y Kurz and Kasch Inc Dayton Ohio Kilka Electric Corp Mt Vernon N Y Littlefuse Inc Des Plaines 10 Minnesota Mining and Mfg Co St Paul Minn Minor Rubber Co inc Bloomfield N J James Millen Mfg Co Inc Malden Mass J W Miller Co Compton Calif Cinch City of Industry Calif Oak Mfg Co Div of Oak Electro Netics Corp Crystal Lake 11 Bendix Corp Electrodynamics Div No Hollywood Calif Painut Co Mountainside N J Patton MacGuyer Co Providence Phaostron Instrument and Electronic Co South Pasadena Calif Philadelphia Steel and Wire Corp Philadelphia Pa American Machine and Foundry Co Princeton Ind TRW Electronic Components Div Camden N J Resistance Products Co Harrisburg Pa Illinois Tool Works Inc Elgin Ill Everlook Chicago Inc Chicago 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 I C N Y Whitehead Metals Inc New York N Y Continental Wirt Electronics Corp Philadelphia Pa Zierick Mfg Co Mt Kisco Mepco Morristown N J Riverside Calif Racine Wisc Grayhill Inc La Grange Ill International Rectifier Segundo Calif Columbus
11. In addition the 6260B 6261B and 6268B need a replacement circuit breaker and the 6260B needs a replace ment T1 power transformer Complete line voltage con version instructions are given in paragraphs 2 20 through 2 27 2 19 Converting 60Hz instrument to 50Hz operation requires that one resistor be replaced and some adjustments be made Line frequency conversion instructions are given in paragraph 2 28 2 20 Converting a Standard Instrument to 208 Volt Operation Models 6259B 6261B and 6268B 2 21 To convert these 230 volt instruments to 208 volt operation proceed as follows a Disconnect instrument from power source and remove top and bottom covers b Remove A2 assembly as described steps through c of paragraph 5 65 This provides access to bias transformer A3T2 see Fig 7 2 Locate the wire that connects circuit breaker CB1 to the 2 bias transformer terminal marked 230 disconnect it from the transformer and reconnect it to the terminal marked 208V Leave the wire from fan B2 not used in the 6259B connected to the terminal marked 230 see Fig 2 2B d Re install the RFI assembly by reversing the proce dure of step b above e Unsolder the wire connected to terminal 5 of power transformer T1 and solder it instead to terminal 4 see Figure 2 3B 2 22 Converting a Standard Instrument to 208 Volt Operation Models 6260B and 6269B 2 23 To convert these 230
12. OPERATING REGION CONSTANT CURRENT OPERATING REGION RE Rone Ro SHORT CIRCUIT LOAD s Eg FRONT PANEL VOLTAGE CONTROL SETTING 1g FRONT PANEL CURRENT CONTROL SETTING ES CRITICAL OR CROSSOVER VALUE ig OF LOAD RESISTOR Figure 4 2 Operating Locus of a CV CC Power Supply 4 2 4 14 The turn on control circuit is a long time constant network that gives the supply a gradual turn on characteristic The slow turn on feature protects the preregulator triac and the series regulator from damage that might occur when ac power is first applied to the unit At turn on the control circuit sends inhibiting voltages to the preregulator control and the series regulator via the error and driver amplifiers After a brief delay the inhibiting voltages are removed and the circuit has no further control over the operation of the supply 4 15 The reference supply provides stable reference voltages used by the constant voltage and current compara tors Less critical operating voltages are obtained from unregulated bias supply 4 16 DETAILED CIRCUIT ANALYSIS 4 17 Preregulator Control Circuit 4 18 The preregulator minimizes the power dissipated by the series regulating transistors during input line voltage or dc output voltage variations Preregulation is accom plished by a phase control circuit using triac A2CR1as the switching element 4 19 The tr ac is a bi directional device it can conduct cu
13. as a slave supply the master supply does not have to be an auto series model Auto Tracking Operation Auto tracking is similar to auto series operation except that two or three supplies share a common negative output bus and are interconnected so that the output voltage of each slave supply is maintained at some constant fraction of that of the master supply of the supplies are controlled through the master supply and each supply feeds a separate load 1 8 SPECIFICATIONS 1 9 Detailed specifications for these power supplies are given in Table 1 1 1 10 OPTIONS Option No 1 11 Options are customer requested factory modifica 020 tions of a standard instrument The following options are available for the instruments covered by this manual Where necessary detailed coverage of the options is included throughout the manual Option No Description 021 005 Realignment for 50Hz Operation Standard instruments are designed for 57 to 63Hz operation For 50Hz operation a resistor in the preregulator control circuit is changed and the preregulator is realigned 007 Ten Turn Output Voltage Control A ten 022 turn control replaces the coarse voltage con trol for improved resolution in setting the output voltage 026 008 Ten Turn Output Current Control A ten turn control replaces the coarse current control for improved resolution in setting the output current 009 Ten Turn Output Voltage and Current Controls Thi
14. f Parts not identified by a reference designator are listed at the end of Table 6 4 under Mechanical and or Miscellaneous The former consists of parts belonging to and grouped by individual assemblies the latter consists of all parts not immediately associated with an assembly 6 3 ORDERING INFORMATION 6 4 To order a replacement part address order or in quiry 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 designator and description To order a part not listed in Table 6 4 give a complete description of the part its func tion and its location Table 6 1 Reference Designators assembly miscellaneous blower fan capacitor fuse 8 circuit breaker jack jumper electronic part CR diode relay DS device signaling inductor lamp meter Table 6 1 Reference Designators Continued 7 plug transistor resistor switch transformer terminal block 7 thermal switch vacuum tube neon bulb photocell etc zener diode socket integrated cir cuit or network Table 6 2 Description Abbreviations A ampere ac alternating current assy assembly bd board bkt bracket 9C degree Centigrade cd coef coefficient comp composit
15. in the load leads the normal strapping pattern shown in Figure 3 2 will not provide the best possible voltage regula tion at the load 1f for example one were to use 4 gauge wire to connect a load that is located only 5 feet from a Model 62598 10V supply the full load regulation measured at the load would be about 120 millivolts as com pared to the 1 2 millivolt regulation that could be measured at the supply s output terminals Thus even relatively short load leads can cause a considerable degradation of the sup ply s performance The remote sensing connections shown in Figure 3 3 improve the voltage regulation at the load by monitoring the voltage there instead of at the suppl y s output terminals The advantages of remote sensing apply only during constant voltage operation 3 29 As be seen in Figure 3 3 remote sensing involves removing the S and S jumpers from the output terminals connecting the load leads normally and using a separate pair of wires to connect the S and S sensing terminals to the load The following paragraphs discuss some precautions that should be observed when making a remote sensing installation NOTE The S jumper is the one that links the S terminal to the OUT terminal when the supply s terminals are strapped for normal operation as shown in Figure 3 2 The 5 jumper is the one that links the S terminal to the OUT terminal 3 30 The load leads should be of the heavies
16. 0033 1853 0099 1854 0071 1853 0099 1853 0041 1854 0071 1853 0099 1854 0071 1853 0099 1854 0071 0757 0344 0686 3905 0686 8205 0686 1615 0811 2099 0811 1860 0811 2099 REF DESIG AND MODELS R6 6259B 60B 618 6268B 69B R20 R21 R22 R23 R24 6259B 60B 61B 6268 698 R25 6259B 60B 61B 6268B 698 R26 R27 R28 29 R30 R31 R35 36 R37 R40 R41 R42 R43 R44 R45 6259B 60B 61B 62688 69B R46 R47 R48 R49 R50 R51 R52 R53 R54 R55 6259B 60B R56 R57 6259B 60B 6261B 62688 69B R58 62598 60B 62618 62688 69B R60 Table 6 4 Replaceable Parts DESCRIPTION fxd ww 470 5 3W fxd ww 1k 5 3W fxd film 330 1 1 8W fxd film 200k 1 1 8W fxd film 196 1 1 8W fxd film 1 21k 1 1 8W fxd film 7 5k 1 1 8W fxd film 127k 1 4 1 8W fxd film 5 49k 1 1 8W fxd film 90 9k 1 1 8W fxd film 21 5 1 1 8W fxd comp 3 9M 596 1 2W fxd comp 3 3 5 1 2W fxd comp selected 5 1 2W fxd ww 2 6k 5 3W fxd comp 10k 5 1 2W fxd comp 180k 5 1 2W fxd comp 1 5k 5 1 2W fxd comp 510 5 1 2W fxd comp 560 1 1 4W fxd ww 50 5 5W fxd met 22 5 2W fxd comp 1k 5 1 2W fxd comp 820 5 1 2W fxd comp 1k 5 1 2W var ww 5k 20 fxd comp 5 1k 5 1 2W fxd comp 47 596 1 2W fxd comp 39 5 1 2W fxd comp 1k 5 1 2W fxd film 61 9k 1 1 8W fxd comp 560 595 1 2W fxd ww 50 5 SW fxd ww 50 5 SW fxd comp
17. 0403 0002 2680 0214 0340 0166 0340 0415 2190 0898 0340 0174 0340 0795 06259 60005 06260 60009 06261 60006 06268 60009 06269 60009 Table 6 4 Replaceable Parts REF DESIG MFG MFG HP AND MODELS DESCRIPTION PART NUMBER CODE PART NUMBER meter bezel 2 4040 0293 spring compression meter mount 1460 0256 aty 8 knob qty 4 bushing R125 mount retainer push on DS1 and DS2 aty 2 handle qty 2 screw 10 32 1 75 for handles qty 4 0370 0084 1410 0052 0510 0509 5020 5762 2680 0173 Chassis Mechanical chassis assembly welded 28480 5060 7972 60B 61B 68B capacitor tray 28480 5000 6243 capacitor tray 28480 06269 00002 circuit board tray 28480 5000 6248 filter mounting bracket 28480 5000 6257 qty 2 6260B 61B 688 fan mounting bracket B2 aty 2 28480 5000 6258 62698 fan mounting bracket B2 qty 2 28480 06269 00004 rubber bumper 3 28480 0430 0085 6259B 68B 69B capacitor clamp sheetmetal qty 2 28480 5000 6017 62608 61B capacitor clamp sheetmetal qty 3 28480 5000 6017 6259B 60B 61B 68 capacitor busbar C101 103 aty 2 28480 5000 6253 6260B 61B capacitor busbar C104 105 qty 2 28480 5000 6251 6269B capacitor busbar C101 104 4 28480
18. 1045 0686 1045 R85 fxd comp 9 1k 5 1 2W EB 9125 0686 9125 R86 6259B 60B 61B fxd met ox 330 5 2W C428 0698 3631 6268B 69 fxd met ox 270 5 2W C428 0698 3629 R87 fxd met 1 5k 5 2W C428 0698 3338 R88 fxd comp 10 5 1 2W EB 1005 0686 1005 6 7 REF DESIG AND MODELS R90 R91 R92 R93 R94 R95 62598 60B 618 6268B 698 R96 R97 R98 R99 R101 R102 62598 608 62618 6268B 69B R103 6259B 608 6268B 69B R104 6259B 60B 6261B 6268B 69B R105 R106 R108 109 R110 R117 R120 T70 90 VR1 40 VR6O 61 VR90 21 72 C1 2 C3 C4 CRI J1 2 6259B 60B 61B 68B J3 62598 60B 61B 68B Table 6 4 Replaceable Parts DESCRIPTION fxd met ox 820 596 2W fxd comp 180 5 1W fxd ww 220 5 2W fxd comp 3 9k 5 1 2W fxd comp 510 596 1 2W ixd film 3k 1 1 8W fxd film 1 5k 1 1 8W fxd comp 200k 5 1 2W fxd comp 4 7 5 1 2W fxd comp 10 5 1 2W fxd comp 10k 5 1 2W var ww 250 20 fxd film 825 1 1 8W fxd film 900 1 1 8W fxd film 909 1 1 8W fxd film 1 21k 1 1 8W fxd film 1 5k 1 1 8W fxd film 4 53k 1 1 8W fxd film 10k 1 1 8W fxd film 19 1k 1 1 8W fxd film 422 1 1 4W var ww 250 20 fxd comp 100 5 1 2W not supplied see Fig 7 8 note 14 not supplied see Fig 7 8 note 14 fxd film 4 7k 5 1 4W pulse transformer diode zener 4 22V 5 diode zener 6 2V 5 diode zener 6 19V 5 dual diff amp IC resistor ne
19. 5 10 turn Series 8400 2100 1865 var ww 10k 5 10 turn Series 8400 2100 1866 1 23 var ww 200 5 10 turn Series 8400 2100 1863 knob qty 2 0370 0137 OPTION 010 Chassis Slides slides CTS 120 E6 5A218 1490 0870 OPTION 013 3 Digit Decadial Voltage Control fxd comp selected 5 1 2W A1R3 5 121 A1R30 A5R123 var ww 2k 5 10 turn Series 8400 2100 2029 var ww 5k 5 10 turn Series 8400 2100 1865 var ww 10k 5 10 turn Series 8400 2100 1866 3 digit turns counting dial 411 1140 0020 OPTION 014 3 Digit Decadial Current Controi fxd comp selected 5 1 2W var ww 200 5 10 turn 3 digit turns counting dial EB Series 8400 411 2100 1863 1140 0020 OPTION 016 115Vac Input Available in Model 6260B only 6 14 Table 6 4 Replaceable Parts MFG MFG HP DESCRIPTION PART NUMBER CODE PART NUMBER circuit breaker 30A 250Vac 2 pole 3105 0036 REF DESIG AND MODELS CB1 62608 Ti AM2 A3 A 30 3 06260 80094 power transformer 0698 3633 fxd met 390 5 2W jumpers for 115Vac operation see Section 11 for complete input voltage conversion instructions omit for 115Vac operation OPTION 020 Adjustable Voltage Programming 1 1 omit 1 111 fxd film 221k 1 1 8W CEA T 0 07716 0757 0473 ATR1
20. 75 5 1 2W fxd ww 1 5 2W fxd ww 1 8 5 2W fxd ww 3 9 5 2W fxd ww 50 5 10W fxd ww 135 5 10W fxd ww 400 5 10W fxd film 600 1 1 8W 6 6 MFG PART NUMBER 242E4715 RS 2B CEA T 0 CEA T 0 CEA T 0 CEA T 0 CEA T 0 CEA 993 CEA 0 CEA 993 CEA T 0 EB 3955 EB 0335 EB 242E2625 1035 1845 1525 5115 T 0 242 5005 C428 EB 1025 EB 8215 EB 1025 110 F4 EB 5125 EB 4705 EB 3905 EB 1025 0 5615 243 5005 243E5005 EB 7505 BWH BWH BWH 10XM 10XM 10XM CEA T 0 HP PART NUMBER 0811 1555 0813 0001 0698 5663 0757 0472 0698 3440 0757 0274 0757 0440 0698 6659 0698 3382 0757 0464 0698 3430 0686 3955 0686 0335 0811 1808 0686 1035 0686 1845 0686 1525 0686 5115 0698 5146 0811 1854 0698 3609 0686 1025 0686 8215 0686 1025 2100 1824 0686 5125 0686 4705 0686 3905 0686 1025 0757 0460 0686 5615 0811 1854 0811 1854 0686 7505 0811 1666 0811 1669 0811 1673 0811 1902 0811 1905 0811 0942 0757 1100 Table 6 4 Replaceable Parts REF DESIG MFG AND MODELS DESCRIPTION NUMBER CODE PART NUMBER fxd film 7 5k 1 1 8W T 0 0757 0440 am 6259B 68B 69B fxd met ox 180 5 2W C428 0698 3626 62608 61 fxd met ox 200 5 2W FP 42 0698 3627 R63 fxd met ox 499 1 1 4W CEB T 0 0698 3207 R64 fxd film 2k 1 1 4W CEB T 0 0757 0739 R65 fxd comp 100k 5 1 2W 1045 0686 1045 R66 fxd comp 2
21. 86 5 87 or 5 88 5 81 Zero Output Voltage Standard Instrument With Resistance or Unity Gain Voltage Programming For instruments using either local programming or the remote programming setup shown in Figure 3 4 or 3 5 zero the output voltage as follows Connect digital voltmeter between OUT and OUT bus bars b If unit is to be used in local programming mode turn VOLTAGE controls fully counterctockwise If unit is to be used in remote programming mode connect remote programming setup and adjust remote resistance or voltage to zero c Connect decade resistance box between pads in zero adjust section of A1 main circuit board that are marked A and B in Figure 5 9 These pads are for R110 d Rotate CURRENT controls fully clockwise and turn on supply e Adjust decade resistance box until digital voltmeter reads exactly zero volts f Replace decade resistance box with fixed metal film 196 1 4 or 1 8 watt resistor of same value 5 82 Zero Output Voltage Standard Instrument With Variable Gain Voltage Programming For instruments using the programming setup shown in Figure 3 6 zero the output voltage as follows a Perform steps a and b of paragraph 5 81 b Solder a jumper between pads in zero adjust section of A1 main circuit board that are marked C and D in Figure 5 9 c Connect decade resistance box between pads marked E and F in Figure 5 9 These pads are for resistor R111 5 17
22. Electronics Yonkers N Y Goodyear Sundries amp Mechanical Co Inc New York N Y Airco Speer Electronic Components Du Bois Pa Sylvania Electric Products Inc Emporium Pa Switchcraft Inc Chicago III Metals and Controls Inc Attleboro Mass Bourns Inc Howard Industries Use Code 71785 assigned to Cinch Mfg Co Chicago 64 cove MANUFACTURER ADDRESS Research Products Corp Madison Wisc Rotron Inc Woodstock N Y Vector Electronic Co Glendale Calif Carr Fastener Co Cambridge Mass Victory Engineering Springfield N J Bendix Corp Eatontown N J Herman H Smith Inc Brooklyn N Y Central Screw Co Chicago 111 Gavitt Wire and Cable Brookfield Mass Grant Pulley and Hardware Co West Nyack N Y Burroughs Corp Plainfield N J U S Radium Corp Morristown N J Yardeny Laboratories New York N Y Arco Electronics Inc Great Neck N Y TRW Capacitor Div Ogallala Neb RCA Corp Harrison N J Fibre Co Newark N J Marco amp Oak Industries Anaheim Calif Philco Corp Lansdale Pa Stockwell Rubber Co Philadelphia Pa Tower Olschan Corp Bridgeport Conn Cutler Hammer Inc Lincoln Ili Litton Precision Products Inc USECO Van Nuys Calif Metuchen N J Chicago III Guiton Industries Inc United Car Inc Miller Dial and Nameplate Co EI Monte Calif Chicago Attleboro Mass Columbus Neb Wiliow Grove Pa Freeport III Schiller Pk IM Woburn
23. Mass Mansfield Ohio Quincy Mass Livingston N J Radio Materials Co Augat Inc Dale Electronics Inc Elco Corp Honeywell Inc Whitso Inc Sylvania Electric Prod Essex Wire Corp Raytheon Co Wagner Electric Corp Southco Inc Lester Pa Leecraft Mfg Co Inc L L C N Y Methode Mfg Co Rolling Meadows III Bendix Corp Franklin Ind Weckesser Co Inc Chicago Amphenol Corp Janesville Wis Industrial Retaining Ring Co Irvington N J Westbury N Y Mamaroneck N Y IMC Magnetics Corp Sealectro Corp ETC Inc Cleveland Ohio International Electronic Research Corp Burbank Calif Boston Mass Renbrandt Inc Ci c2 C20 C35 C40 C41 6259B 60B 61B 6268B 69B C44 C60 C61 C70 C7 i C72 73 C90 C91 CR1 7 20 21 3537 CR40 CR41 CR42 CR43 44 CR45 50 53 54 CR60 62 70 84 88 90 93 01 020 40 041 42 O60 061 63 070 71 072 73 090 091 92 R1 R2 6259B 60B 62618 6268B 69B R3 R4 R5 6259B 60B 61B 62688 69B Note 1 This assembly is designed for component levei repair Replacement assemblies cannot be supplied Table 6 4 Replaceable Parts A1 Main PC Board Electrical See Note 1 fxd polyester 200V fxd elect 50V fxd elect 68uF 15V fxd elect 20uF 50V fxd polyester 0224F 200V fxd polyester 022uF 200V fxd polyester 01uF 200V fxd elect 1400uF 30
24. R86 C73 81 and TP103 or period incorrect Table 5 8 Checks and Adjustments Required After Semiconductor Replacement Im FUNCTION OR CIRCUIT CHECK ADJUST R110 or R113 Option 020 or 040 R117 or R119 Option 021 or 040 See para 5 81 thru 5 85 or 5 91 thru 5 95 as applicable 01 Voltage clamp circuit CC load regulation 020 Short circuit protection Output current CV CC load regulation CV transient R47 See para 5 98 response Constant voltage CV iine and load regu lation Zero voit output Constant current CC tine and load regu lation Zero current output Constant voltage and constant current differential amplifiers Mixer amplifier 042 A4Q101 CV CC load regulation A40102 Driver and error amplifiers Reference regulator 12 4 6 2V and 6 2V reference 062 voltages and reference circuit line regulation Overvoltage limit Limiting action and level 513 Table 5 8 Checks and Adjustments Required After Semiconductor Replacement Continued REFERENCE FUNCTION OR CIRCUIT ADJUST 071 Q72 Preregulator control circuit Output voltage ripple imbalance and R70 R82 See para Q73 preregulator waveforms 5 100 and 5 102 090 O91 Crowbar Crowbar action trip voltage voltage across A5R125 See para 092 series regulator when tripped 5 104 A40103 thru Serie
25. Thomas and Betts Co Philadelphia Union Carbide Corp New York Ward Leonard Electric Co Mt Vernon N Y Amperite Co Inc Union City N J Beemer Engrg Co Fort Washington Pa Belden Corp Chicago ill 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 T T Cannon Electric Inc Los Angeles Calif Globe Union Inc Milwaukee Wis General Cable Corp Cornish Wire Co Div Williamstown Mass Coto Coil Co Inc Providence 1 Chicago Miniature Lamp Works Chicago lll Cinch Mfg Co and Howard B Jones Div Chicago 111 Dow Corning Corp Midland Mich Electro Motive Mfg Co Inc Willimantic Conn Dialight Corp Brooklyn N Y General Instrument Corp Newark N J Drake Mfg Co Harwood Heights Ill Elastic Stop Nut Div of Amerace Esna Corp Erie Technologicat Products Union N J Erie Pa Hart Mfg Co Hartford Conn Beckman Instruments Fullerton Calif Fenwal Inc Ashland Mass Hughes Aircraft Co Electron Dynamics Div Torrance Calif Amperex Electronic Hicksville N Y Bradley Semiconductor Corp New Haven Conn Carling Electric Inc Hartford Conn Federal Screw Products Inc Chicago lll Heinemann Electric Co Trenton N J Hubbell Harvey Inc Bridgeport Conn Amphenol Corp Amphenol RF Div Danbury Conn E F Johnson Co Waseca Minn Table 6 3
26. a difference voltage between the two inputs of the differential amplifier This difference voltage is amplified and appears at the output of the differential amplifier pin 12 as an error voltage which ultimately varies the conduction of the series regulator 4 37 Resistor R6 in series with the summing point input to the differential amplifier limits the current flow ing into the differential amplifier during rapid voltage turn down Diode CR7 prevents excessive current drain from the 6 2 volt reference supply during rapid down program ming Diodes CR5 and CR6 prevent excessive voltage excursions from overdriving the differential amplifier 4 38 During constant voltage operation the program ming current flowing through the programming resistors VOLTAGE controls is constant because the summing point is held constant at zero volts by feedback action and virtually all of the reference supply current flowing through pull out resistors R3 R4 and R5 flows through VOLTAGE controls A5R121 A5R122 Linear constant voltage programming is thus assured Resistor R3 serves as a trimming adjustment for the programming current flowing through A5R121 and A5R122 If the supply is equipped with Option 020 or 040 resistor R111 and potentiometer R112 allow the programming current to be adjusted over a narrow range around its nominal value In practice this adjustment sets the power supply output to exactly the 4 5 maximum rated volta
27. adjacent sawtooth peaks should be within 2596 of each other f If amplitude difference is greater than 25 turn off supply and replace R82 with decade resistance g Turn on supply and adjust decade resistance to reduce imbalance to within 25 h Vary input line voltage from 208 to 254Vac and insure that excessive imbalance does not exist anywhere within this range Replace decade box with equivalent resistor NOTE If imbalance cannot be reduced to within 25 check capacitors C70 and C72 and diodes CR79 through CR84 If these components test satisfactorily the problem may be due to distortion present on the ac power line 5 102 Preregulator Tracking Adjustment 5 103 To adjust the voltage drop across the series regu lator proceed as follows a Connect load resistor specified in Figure 5 1 across rear output terminals of supply b Connect variable autotransformer between input power source and power supply input and adjust it for a 230Vac input to the supply Connect dc voltmeter across series regulator between TP102 and TP103 d Turn CURRENT controls fully clockwise e To check voltage drop across regulator at low output voltage short circuit the load resistor and adjust VOLTAGE controls for maximum rated output current on front panel ammeter Adjust R70 RAMP ADJ until voltmeter reads 3 5 0 3Vdc g To check the voltage drop at high output voltage remove short circuit from across load resistor and
28. adjust VOLTAGE controls for maximum rated output current Voltmeter reading should again be 3 5 0 3Vdc h Vary input line voltage from 208 to 254Vac Voltmeter reading should vary between 3 2 and 3 8Vdc If reading exceeds this range proceed to step i i Replace R77 with decade box Vary input line voltage between 208 and 254 Vac and adjust decade box until voltmeter reading variation is minimal and within range of 3 2 to 3 8Vdc Replace decade box with equivalent resistor 5 104 Crowbar Trip Voltage Adjustment 5 105 adjust the voltage at which the crowbar fires proceed as follows Turn front panel OVERVOLTAGE ADJUST potentiometer A5R125 fully clockwise b Turn on supply Set output voltage to desired trip voltage d Turn A5R125 slowly counterclockwise until the crowbar fires amber OVERVOLTAGE lamp lights and voltmeter indication falls to zero Turn off supply and turn down output voltage controls f Turn on supply and set desired output voltage NOTE It is recommended that the crowbar trip volt age be set higher than the normal output volt age by no less than 5 of the output voltage plus 2 volts for the Models 6259B 6260B or 6261B or 5 of the output voltage plus one volt for the Models 6268B or 6269B If an occasional tripping of the crowbar can be tolerated as a load is being disconnected the crowbar trip point can be set much closer to the operating voltage of the supply 5 106 Maxi
29. be used as the master CROWBAR TRIGGER AI A2 A4 5 AB t S A9 o o o MASTER GND 1815218 2 A3 4 5 AG 8 5 SLAVE NO I GND Rx2 o 25 t A2 4 5 6 8 5 le SLAVE NO 2 Figure 3 13 Auto Series Operation of Three Units 3 69 Determining the Value for Each slave supply has an external resistor Rx associated with it that supplies its voltage programming current If the temperature coefficient and stability specifications of the supplies are to be maintained these must be stable low noise resistors with a temperature coefficient of less than 30ppm per and power rating at least 30 times what they will actually dissipate To calculate the proper value for Rx for each slave the following information is required a the rated maximum voltage of the master supply b the corresponding maximum voltage desired of the slave supply with its voltage control set to maximum the resistance of the slave supply s coarse voltage control The Rp values for the supplies included in this manual are as follows Model 62598 62608 2 5kQ 6261B 62688 62698 10k use the formula Rx Rp Eg Rp For example if the slave supply is a Model 6259B and we want its output to vary from zero to 10 volts as the master supply varies from zero to 40 v
30. d Perform steps d through f of paragraph 5 81 5 83 Zero Output Voltage Option 020 Instrument With Resistance or Unity Gain Voltage Programming For Option 020 instruments using either focal programming or the remote programming setup shown in Figure 3 4 or 3 5 zero the output voltage as follows a Perform steps a and b of paragraph 5 81 b Rotate CURRENT controls fully clockwise and turn on supply If reading on digital voltmeter is not exactly zero volts adjust potentiometer R113 labeled VOLTAGE ZERO and accessible through hole in rear panel until reading is exactly zero 5 84 Zero Output Voltage Option 020 Instrument With Variable Gain Voltage Programming For Option 020 instruments using the programming setup shown in Figure 3 6 zero the output voltage as follows a Perform steps a and b of paragraph 5 81 b Rotate CURRENT controls fully clockwise and turn on supply c If reading on digital voltmeter is not exactly zero volts adjust potentiometer R112 labeled VOLTAGE PROG and accessible through hole in rear panel until reading is exactly zero 5 85 Zero Output Voltage Option 040 Instrument Zero the output voltage of Option 040 instruments as follows a Connect digital voltmeter between OUT and OUT bus bars b Connect a 102 196 programming resistor as shown in Figure 3 4 c Rotate CURRENT controls fully clockwise and turn on supply d Adjust potentiometer R113 labeled VOLT
31. lele e A4 A5 A7 A8 S S A9 VOLTAGE SOURCE RR gt Figure 3 6 Voltage Programming of Output Voltage Variable Gain 3 46 With zero ohms connected across the programming terminals the output current of the supply may be set to exactly zero either by installing and adjusting R117 as described in paragraph 5 91 or if the instrument is equipped with Option 021 or 022 by adjusting potentiometer R119 as discussed in paragraph 5 93 CAUTION Do not allow programming terminals A4 or A6 to become open circuited while resistance programming the output current If they do open the supply s output current rises to a value that may damage the supply or the load If in the particular programming con figuration used there is a chance that the terminals might open we suggest that a 200 ohm resistor be connected across the programming terminals Of course when this resistor is used the resistance value actually programming the supply is the parallel combination of the remote programming resistance and the resistor across the programming terminals Like the program ming resistor this resistor should be a low noise low temperature coefficient type 3 47 Constant Current Output Voltage Input Fixed Gain The rear panel connections shown in Figure 3 8 allow the output current to be varied by using an external voltage source to progr
32. minute warmup Constant Current Models 6259B 62618 and 62698 Less than 0 01 plus 4mA change in output per degree Celsius change in ambient following a 30 minute warmup Model 6260B Less than 0 01 plus 8mA change in output per degree Celsius change in ambient following 30 minute warmup Model 6268B Less than 0 01 plus 2mA change in output per degree Celsius change in ambient following a 30 minute warmup DRIFT STABILITY Change in output dc to 20Hz over an 8 hour interval under constant line load and ambient temperature follow ing a 30 minute warmup Constant Voltage Less than 0 0376 of output plus 2mV Constant Current Models 6259B 6261B and 6269B Less than 0 0376 of output plus 10mA Model 6260B Less than 0 03 of output plus 20mA Model 6268B Less than 0 03 of output plus bmA 13 Table 1 1 Specifications Models 6259B 62608 62618 6268B 6269B Continued LOAD TRANSIENT RECOVERY TIME Less than 0 is required for output voltage recovery in constant voltage operation to within 10mV of the nominal output following a change in output current equal to the current rating of the supply or 5 amps whichever is smaller REMOTE PROGRAMMING COEFFICIENTS Output Voltage Programming Resistance Voltage Model Control 196 Control 51 Models 2002 1V N Output Current Programming Resistance Voltage Model Control
33. pickup problems associated with constant voltage ripple and noise measurement also apply to the measure ment of constant current ripple and noise Figure 5 8 illustrates the most important precautions to be observed when measuring the ripple and noise of a constant current POWER SUPPLY UNDER TEST DIGITAL RESISTCR VOLTMETER CURRENT SAMPLING RESISTOR Rs LOW TC ALLOY 20 ppm 0 012 0 0052 0 01670 0 01 MODEL 5 62598 62608 0 192 500w 0 0952 000 62618 0 392 10009 6268B 1 310 12004 62698 0 790 2000 Figure 5 7 Constant Current Load Regulation Test Setup POWER SUPPLY CASE OSCILLOSCOPE CASE A INACCURATE METHOD USING SINGLE ENDED SCOPE GROUND CURRENT IG PRODUCES 60CYCLE DROP IN NEGATIVE LEAD WHICH ADDS TO THE POWER SUPPLY RIPPLE DISPLAYED ON SCOPE POWER SUPPLY CASE OSCILLOSCOPE CASE SHIELDEO TWO WIRE LENGTH OF LEAD BETWEEN Rg AND GROUNDED OUTPUT TERMINAL OF POWER SUPPLY MUST HELO TO ABSOLUTE MINIMUM B RECOMMENDED METHOD USING A DIFFERENTIAL SCOPE WITH FLOATING INPUT GROUND CURRENT PATH IS BROKEN COMMON MODE REJECTION OF DIFFERENTIAL iNPUT SCOPE IGNORES DIFFERENCE IN GROUND POTENTIAL OF POWER SUPPLY AND SCOPE AND SHIELDED TWO WIRE FURTHER REDUCES STRAY PICKUP ON SCOPE LEADS Figure 5 8 Constant Current Ripple and Noise Test Setup 5 8 supply The presence of a 120Hz waveform on the oscillo scope normally indicates a correct
34. programming accuracy is required it can be obtained either by changing resistor R3 as discussed in paragraph 5 86 or if the instrument is equipped with Options 020 or 022 by adjusting potentiometer R112 as discussed in paragraph 5 87 3 40 With the programming terminals shorted terminals A2 to S the no load output voltage of the supply should be 15mV 5mV If a minimum output voltage is required that is closer to zero than this it can be obtained either EXT CROWBAR TRIGGER 2 A4 5 6 A7 AB S S AD lt 2 PROGRAMMING RESISTOR Figure 3 4 Resistance Programming of Output Voltage by installing and adjusting R110 as discussed in paragraph 5 81 or if the instrument is equipped with Option 020 or 022 by adjusting potentiometer R113 as discussed in paragraph 5 83 CAUTION Do not allow programming terminals A2 or S to become open circuited while resistance programming the output voltage If they do become open circuited the supply s output voltage tends to rise beyond its rated maximum 1f the supply s current controls and over voltage crowbar trip point are properly adjusted however no damage to the power supply or load should result 3 41 Constant Voltage Output Voltage Input Unity Gain The rear panel connections shown in Figure 3 5 allow the output voltage to be varied by using an external voltage source to program the s
35. that is conducting at the time Diode is forward biased and CR20 reverse biased during constant voltage operation The reverse is true during constant current operation 4 50 Transistor Q40 provides a constant current to the collector of Q41 and also generates a negative going turn off signal for the series regulator when the unit is first turned off Feedback network C41 R47 and R53 shapes the high frequency rolloff in the loop gain response in order to stabilize the series regulator feedback loop 4 51 Error amplifiers Q42 and A4Q101 serve as the pre driver elements for the series regulator 40101 also provides a discharge path for the output capacitors in order to allow faster down programming and conducts a bleed current for the series regulator to keep it in its active region when the supply is set for zero output current Diode CR44 prevents A40101 s base from going more negative than 3 volts in order to limit the bleed current through R57 and protect 40101 from damage if a voltage higher than the program med output voltage is applied across the output terminals 4 52 Overvoltage Protection Crowbar 4 53 The overvoltage protection crowbar circuit protects sensitive loads against the application of an excessively high voltage as might result from a series regulator transistor failure It accomplishes this by immediately shorting the output of the supply as soon as a preset threshold voltage is exceeded Until silico
36. the disconnected wire replace the A2 assembly and replace the bottom cover of the supply The substitute capacitor should have approximately the same capacitance an equal or greater voltage rating and good high frequency characteristics Connect it directly across the load using the shortest possible leads Readjust equali zation control R47 as in step a above after installing the substitute output capacitor 3 34 Remote Programming 3 35 The output voltage or current of these power supplies can be remotely controlled by connecting an external resistor or applying an external voltage to rear pane terminals f resistance programming is used a variable resistor can control the output over its entire range Or a variable resistor connected in series with a fixed resistor can have its control restricted to a limited portion of the output range Alternately a switch can be used to select fixed values of programming resistance to obtain a set of discrete voltages or currents The switch must have make before break contacts to avoid producing the output voltage transients that momentarily opening the programming terminals would cause To maintain the temperature and stability specifications of the supply programming resistors must be stable low noise resistors with a temperature coefficient of less than 30ppm per C and a power rating at least 30 times what they will actually dissipate 3 36 Both voltage and current outputs can also
37. tracks the voltage of the first slave For this reason the voltage of the master must be adjusted to maximum and then each slave in turn must be set to the corresponding voltage desired during initial setup of the auto series combination Once this has been done the total voltage of the combination can be controlled by the voltage controis of the master supply or it can be remotely program med through the master supply 3 63 Setting the Current Controls Auto series opera tion leaves the current controls of all supplies operative but the supply whose current contro has the lowest setting determines the point at which automatic crossover to constant current operation begins to lower its output volt age and thus that of the series combination The constant current circuit of a supply has no effect on the outputs of the supplies connected in a more positive position in the series combination but it does affect its own output and the outputs of the supplies connected in a more negative position If the current controls of one of the slave supplies are set the lowest then an overload or short circuit at the output wil cause the master supply or the master and the first slave to force current through the reverse voltage protection diodes at the outputs of the downstream slaves Because this current could be excessive either for the diodes EXT CROWBAR TRIGGER 2 A4 A5 6 AT AB S MA
38. 00k 596 1 2W EB 2045 0686 2045 R67 fxd comp 33k 5 1 2W EB 3335 0686 3335 R68 fxd film 5 49k 1 1 8W CEA T 0 0698 3382 R69A fxd film 7 5k 1 1 8W CEA T 0 0757 0440 R69B fxd film 3 4k 1 1 8W CEA T 0 0698 4440 R70 var ww 5k 20 110 F4 2100 1824 R71 fxd film 12k 1 1 8W CEA 0 0698 5088 R72 6259B 60B fxd film 12k 1 1 8W CEA T 0 0698 5088 6261B fxd film 23k 1 1 8W CEA T 0 0698 3269 6268B 69B fxd film 45k 1 1 8W CEA T 0 0698 5091 R73 fxd comp 12k 5 1 2W EB 1235 0686 1235 R74 fxd comp 82k 5 1 2W 8235 0686 8235 R75 6259B fxd film 2 37k 1 1 8W CEA 0 0698 3150 62608 618 68B 69B fxd film 4 75k 1 1 8W CEA T 0 0757 0437 R76 6259B fxd film 3 4k 1 1 8W CEA T 0 0698 4440 62608 618 68B 69B fxd film 4 75k 1 1 8W CEA T 0 0757 0437 R77 6259B fxd comp 200k 5 1 2W EB 2045 0686 2045 6260B fxd film 68 1k 1 1 8W CEA T 0 0757 0461 62618 fxd film 110k 1 1 8W CEA T 0 0757 0466 6268B 69B fxd comp 430k 5 1 2 EB 4345 0686 4345 R78 6259B 60 fxd film 60 4k 1 1 8W CEA T 0 0698 3572 62618 fxd film 118k 1 1 8W CEA T 0 0698 3265 62688 69B fxd fitm 249k 196 1 8W CEA T 0 0757 0270 R79 fxd comp 1 8k 5 1 2W EB 1825 0686 1825 R80 fxd film 4 32k 1 1 8W CEA 0757 0436 R81 fxd comp 4 7 5 1 2W EB 47G5 0698 0001 R82 fxd 9 1 5 1 2W 9125 0686 9125 R83 6259B 60B 61B fxd comp 30 5 1 2W EB 3005 0686 3005 6268B 69B fxd comp 27 5 1 2W EB 2705 0686 2705 R84 fxd comp 100k 5 1 2W EB
39. 020 5763 5020 5765 6259B 61B 68B 69B front rectifier heatsink 28480 CR101 102 C1 2 62598 61B 68B 69B rear rectifier heatsink 28480 CR103 104 C3 4 6260B front and rear rectifier heatsink 28480 CR101 front CR102 rear qty 2 rear transistor heatsink Q103 106 28480 TS101 6259B 61 68 center front heatsink blank 28480 62608 front transistor heatsink Q107 110 28480 6269B front transistor heatsink Q107 108 28480 top left heatsink CR105 CR110 28480 Q101 6259B 61B 68B 69B bottom left heatsink CR106 CR108 28480 Q102 6260B bottom left heatsink CR106 108 28480 0102 left end fan mounting bracket 28480 right end mounting bracket 28480 insulating spacer strip qty 2 28480 plastic support rods qty 4 28480 flat nylon spacing washers qty 8 28480 nylon shoulder washers qty 8 28480 sleeving for R106 28480 rubber bumper 28480 screw R123 mounting 10 32 1 4 28480 Phillips qty 2 transistor pin insulator qty 4 each 28480 103 110 insulated bushing CR110 28480 insulating shoulder washer CR110 28480 transistor insulator mica Q101 102 28480 2 transistor insulator plastic 28480 0101 102 qty 2 5 Front Panel Ass y Mechanical front panel front panel front panel front pane front panel 6 12 5020 5766 5020 5766 5000 6256 5000 6255 5020 5787 0380 0901 3050 0455 3050 0483 0890 1055
40. 08 62698 ONLY 62608 52698 ONLY 1 oV 3 o NOT IN MODEL 62608 EMITTER RESISTOR INSULATING INSULATING mmm CIRCUIT BOARD SPACING SHOULDER AARI23 EE SEE TABLE BFLOW WASHERS WASHERS FRONT AARIZ3A AND FIG 7 9 8 PLACES IN PARALLEL 6 IN MODEL 62608 4452 INSULATING NOT IN SHOULDER 58 MODEL WASHERS e 62608 8 PLACES N AACRIOT A4CRIO6 A4Q 09 AAQIIO A4CRIO2 4 MODEL 62608 ONLY MODEL 62608 ONLY MODEL 62608 ONLY NOT LOCATED MERE IN MODEL 6260B EMITTER RESISTOR CKT BD TABLE 62598 6261B A4RI5O ASRIS7 48150 A4RI6S A4RISO A4RISS A4RISO 448155 Figure 7 5 A4 Heatsink Assembly Top and Front View ASCRIOT AACRIO6 40109 A4QiI0 A4CRIO2 MODEL 62608 ONLY MODEL 62608 ONLY MODEL 62606 ONLY NOT LOCATED HERE IN MODEL 62608 4465 5 NOT IN MODEL 62608 AACRIOS a NOT IN MODEL BOTTOM 62608 A4CRIOB 449102 440103 440104 5 n B o 2 6 2 nr NOT IN MODEL 62608 5 1 3 A4TSIOI UE Q A4RIOG i AARI23 aace oel 62608 s e Nr AACRIIO 40101 440105 440106 A4CRIO4 pu A4CRIO2 IN MODEL 62608 Figure 7 6 A4 Heatsink Assembly Bottom and Rear View B mE CREE M NEAL DRED SS CRT CIRCUIT SIDE COMPONENT SIDE METE 8 CIRCUIT NOTES amp RBG RET Ri F 99
41. 10 Contro 10 6259B AQ A 10mV A 6260B 20 A 5mV A 62618 4Q A 10mV A 6268B 60 A 16 7mV A 62698 4Q A 10mV A REMOTE PROGRAMMING SPEED Typical time required to nonrepetitively change from zero to within 99 9 of the maximum rated output voltage or from the maximum rated output voltage to within 0 196 of that voltage above zero Model Up Full Load Down Load 62598 70ms 10ms 6260B 70ms 5ms 6261B 150ms 25ms 6268B 300ms 30ms 6269B 350ms 20ms Model Up No Load Down No Load 6259B 70ms 200ms 6260B 70ms 200ms 6261B 150ms 250ms 6268B 300ms 1sec 6269B 350ms 1sec PANEL METERS The accuracy of the front panel voltmeter and ammeter is 2 of full scale The ranges of these meters are Model Model 6259B 12V 60A 6268B 50V 35A 6260B 12V 120A 6269B 50V 60A 6261B 24V 60A TEMPERATURE RATINGS Operating 0 to 55 C 40 to 75 C Storage COOLING These power supplies are forced air cooled The Model 6259B is cooled by a single fan the other models are cooled by two fans RESOLUTION Minimum output voltage or current change that can be obtained using the front panel controls Model Constant Voltage Constant Current 6259B 1 50 62608 1mV 100mA 6261B 2mV 50mA 6268B 5mV 30mA 6269B 5mV 50mA OUTPUT IMPEDANCE TYPICAL Approximated by a resistance in series with an inductance as follows Model 62598 0 05m2 1uH 62608 0 02mQ 1uH 62618 0 01mQ 14H Model 6268 0 2m22 1uH 6269 0 1 1uH
42. 12 113 var ww 5k 5 CT 106 4 84048 2100 1760 A1R114 fxd film 249k 1 1 8W CEA 993 07716 0757 0270 OPTION 021 Adjustable Current Programming omit A1R21 1 115 fxd film 23k 1 1 8W CEA 993 0698 3269 A1R116 var ww 5k 5 CT 106 4 2100 1760 ATR118 fxd film 200k 1 1 8W CEA 993 0757 0472 AiR119 var ww 5k 5 CT 106 4 2100 1760 OPTION 022 Adjustable Voltage and Current Programming omit A1R1 2 1 111 fxd film 221k 1 1 8W CEA 0 0757 0473 1 112 113 var ww 5k 5 CT 106 4 2100 1760 A1R114 fxd film 249k 1 1 8W CEA 993 0757 0270 ATR115 fxd film 23k 196 1 8W CEA 993 0698 3269 A1R116 119 var ww 5 5 CT 106 4 2100 1760 1 118 fxd film 200k 1 1 8W CEA 993 0757 0472 OPTION 026 115Vac Input Available in Models 6259B 6261 and 6268B only CB1 62618 68B circuit breaker 30A 250Vac 2 pole AM2 A3 A 30 3 74193 3105 0036 A2R3 6259B 618 68B fxd met ox 390 5 2W RG42 11502 0698 3633 2 1 2 6259B 61B 68B jumpers for 115Vac operation see Section Il for complete input voltage conversion instructions 6 15 Table 6 4 Replaceable Parts MFG PART NUMBER REF DESIG AND MODELS MFG HP CODE PART NUMBER DESCRIPTION A2J3 62598 61 68B omit for 115Vac operation OPTION 027
43. 2 5mV instead of 5mV 5 26 The circuit of Figure 5 3 can also be used for the normal measurement of low frequency ripple Simply remove the four terminating resistors and the blocking capacitors and substitute a higher gain vertical plug in for the wide band plug in required for spike measurements Notice that with these changes Figure 5 3 becomes a two cable version of Figure 5 2B 5 27 Load Transient Recovery Time Definition The time X for output voltage recovery to within Y millivolts of the nominal output voltage following a Z amp step change in load current where Y is specified as 10 the nominal output voltage is defined as the dc level halfway between the static output voltage before and after the imposed load change and 2 is the specified load current change of 5 amps or the full load current rating of the supply whichever isless Load transient recovery time may be measured at any input line voltage combined with any output voltage and load current within rating 5 28 Measurement Techniques Care must be taken in switching the load resistance on and off A hand operated switch in series with the load is not adequate since the resulting one shot displays are difficult to observe on most oscilloscopes and the arc energy occurring during switching completely masks the display with a noise burst Transistor load switching devices are expensive if reasonably rapid load current changes are to b
44. 208Vac Input No special parts are used in this option OPTION 040 Interfacing for Multiprogrammer Operation The replaceable parts for Option 040 are the same as for Option 022 6 16 SECTION VII CIRCUIT DIAGRAM AND COMPONENT LOCATION DIAGRAMS test points indicated by circled numbers on the circuit schematic of Figure 7 8 correspond to those on the com ponent location diagrams and in the troubleshooting procedures in Section V This section contains the schematic diagram and component location diagrams necessary for maintaining this power sup ply Differences among the five power supply models covered by this manual are indicated where they exist The THIS PAD CONNECTS AC LINE POTENTIAL TO THE A2 ASS Y HEATSINK AND CASE WARNING THE CASE HEATSINK AND CIRCUITRY OF THE A2 RFI ASSEMBLY ARE AT AC LINE POTENTIAL EXERCISE EXTREME CAUTION DURING SERVICING NOTES 1 JUMPERS SHOWN CONNECTED FOR 230VAC INPUT SEE SECTION II FOR VOLTAGE CONVERSION INSTRUCTIONS 2 TRIAC A2CRI IS MOUNTED ON A2 HEATSINK 3 A2R3 1 NOT USED IN INSTRUMENTS EQUIPPED FOR 208 OR 230VAC INPUT Figure 7 1 A2 Assembly Component Locations ee TR AY 5000 6248 A341 BEHIND CIRCUIT BOARD TRAY TO REMOVE A3C3 FROM CIRCUIT INTERCONNECTION DISCONNECT RED WIRE LOCATED CIRCUIT BOARD HERE SEE PARA 3 33b Figure 7 2 A3 Interconnection Board Component Locations
45. 25 Check A4CR110 for short Proceed to step 3 b Check OVERVOLTAGE ADJUST A5R125 Check A4CR110 for open Also check O91 and Q92 Proceed to step 3 c Check OVERVOLTAGE ADJUST A5R125 Check A4CR110 for open Also check O20 Q91 and O92 Proceed to step 3 Off output voltage high Off output voltage low Output voltage normal variable from 0 volts to about 9 volts Check each series regulator transistor A40103 through A4Q106 A40108 or A40110 for open Then check preregulator by disconnecting external source and proceed ing to Table 5 7 b High voltage condition in series regulator Proceed to Table 5 5 Leave external source connected Low voltage condition in series regulator loop Proceed to Table 5 6 Leave external source connected Isolate fault to series regulator or preregulator by proceeding as follows 1 Open the gate lead of triac A2CR1 by disconnecting one end of R88 TP87 or 88 2 Observing correct polarity connect small dc power supply across input capacitor C101 A 0 10V 2A supply is sufficient 3 Set external supply to ten volts 4 Vary front panel voltage controls b Output voltage high Varying controls has little or no effect Output voltage low Varying controls has little or no effect Table 5 5 Series Regulator Troubleshootin
46. 5 depending on the power supply model proceed as follows a Disconnect input power and remove top and bottom covers from the supply b Remove the long flat head screws and V shaped clamps that hold the main filter capacitors in place Trip voltage 5 15 R95 A5R125 See para 5 104 and 5 106 Sufficient lead length is provided to allow capacitors to be lifted partially out of instrument 5 65 A2 Filter Assembly Removal To remove the assembly proceed as follows a Disconnect input power turn supply upside down and remove bottom cover b Remove four screws holding RFI heat sink to mount ing brackets c Lift out assembly and turn over d Remove four screws holding cover to heat sink This allows access to the internal components and 115V 230V jumpers 5 66 A4 Heat Sink Removal In order to gain access to the following components it is necessary to remove the heat sink assembly Transistors A4Q101 through A40110 diodes AACR101 through A4CR108 and A4CR110 resistors A4R106 A4R123 and A4R150 through A4R165 capacitors A4C1 through A4C5 cooling fan 4 1 and thermal switch 475101 For the location of these components see Figures 7 5 and 7 6 To remove the heat sink assembly proceed as follows a Disconnect input power from the supply stand it on its left side and remove top and bottom cover b Remove main printed circuit board as described in paragraph 5 62 c Remove two scr
47. 5000 6251 cover qty 2 28480 5000 9476 rear panet 28480 5000 9475 output busbar qty 2 28480 5000 6252 busbar insulating spacers 28480 0380 0710 312 qty 4 nylon shoulder washers busbar mounting qty 4 ac input insulating spacers 625 qty 2 28480 3050 0483 28480 0380 0703 rubber bumber qty 4 28480 0403 0089 barrier block 3 terminal ac input 603 3 75382 0360 1596 cover ac input barrier block 28480 5000 6249 cover ATTB2 barrier block 28480 00712 20001 binding post chassis ground 83330 1510 0044 Miscellaneous 9211 1181 9220 1402 carton packing floater pad qty 2 6 13 Table 6 4 Replaceable Parts MFG MFG HP DESCRIPTION PART NUMBER CODE PART NUMBER OPTION 005 50Hz AC Input fxd comp 240 5 1 2W REF DESIG AND MODELS EB 2415 01121 0686 2415 OPTION 007 10 Turn Voltage Control AbR121 6259B 60B var ww 2k 5 10 turn Series 8400 2100 2029 62618 var ww 5k 5 10 turn Series 8400 2100 1865 6268B 69B var ww 10k 5 10 turn Series 8400 2100 1866 knob 0370 0137 OPTION 008 10 Turn Current Control var ww 200 5 10 turn knob 2100 1863 0370 0137 Series 8400 84048 OPTION 009 10 Turn Voltage and Current Controls A5R121 6259B 60B var ww 2k 5 10 turn Series 8400 2100 2029 var ww bk
48. 88 69B voltmeter 0 50Vdc 28480 1120 1173 M2 6259B 61B 69B ammeter 0 60A 28480 1120 1181 6260B ammeter 0 120A 28480 1120 1182 6268B ammeter 0 35A 28480 1120 1179 R121 VOLTAGE COARSE control 62598 60B var ww 2 5k 5 Series 43 12697 2100 2745 6261B var ww 5k 5 Series 43 12697 2100 1853 6268B 69B var ww 10k 5 Series 43 12697 2100 1854 R122 VOLTAGE FINE control 6259B 608 var ww 10 5 Series 43 12697 2100 1857 6261B var ww 50 5 Series 43 12697 2100 1858 6268B 69B var ww 100 5 Series 43 12697 2100 1987 R123 CURRENT COARSE control var ww 200 5 Series 43 2100 1856 7 nearest commercial equivalent 6 10 Table 6 4 Parts REF DESIG MFG MFG HP AND MODELS DESCRIPTION PART NUMBER CODE PART NUMBER R124 CURRENT FINE control var ww 10 5 OVERVOLTAGE ADJUST var ww 5k 5 var ww 10k 5 Series 43 2100 1857 R125 62598 60B 6261B 68B 69B Series 43 Series 43 2100 1853 2100 1854 Chassis Electrical B2 6260B 61B 69B fan cooling 115Vac 50 60Hz 8500 3160 0209 6269B fan cooling 115Vac 50 60Hz WS2107FL 55 3160 0056 C19 6259B 60B fxd elect 68uF 15V 150D686X0015R2 0180 1835 62618 fxd elect 22uF 35V 150D226X0035R2 0180 0160 6268B 69B fxd elect 15uF 15V 150D156X0050R2 0180 1834 C101 103 625
49. 96 2 0mV cRe2 060 081 052 063 CR62 cRe2 060 081 052 063 061 062 063 ow vmeo vrer Res VR61 R63 Table 5 3 Overall Troubleshooting SYMPTOM Low or no output voltage OVERVOLTAGE lamp may be on or off High output voltage PROBABLE CAUSE Front panel meter defective b Crowbar not reset or defective Refer to Table 5 4 Series regulator or preregulator feedback loop defective Refer to Table 5 4 Front panel meter defective Series regulator or preregulator loop defective If crowbar does not trip it too is faulty Refer to Table 5 4 Open circuit between sensing terminals 5 and output terminals Refer to Table 5 4 59 Table 5 3 Overall Troubleshooting Continued SYMPTOM PROBABLE CAUSE High ripple a Ground loops in operating setup Refer to paragraph 5 17 b Incorrect reference or bias voltages Refer to Table 5 2 c Supply crossing over to constant current operation under loaded conditions Check current limit setting or constant current comparator circuit 21 and associated components a Improper measurement technique Refer to paragraph 5 13 b Incorrect reference or bias voltages Refer to Table 5 2 Poor line regulation a Improper measurement technique Refer to paragraph 5 11 ncorrect reference or bias voltages Refer to Table 5 2 c Supply current limiting Check consta
50. 9B 60B fxd elect 100000uF 20V 86F697S 0180 2294 6261B 68B fxd elect 40000uF 50V 32D D42343 DQB 0180 1931 6269B fxd elect 50000uF 50V 36D4512 DQOB 0180 2346 C104 62608 fxd elect 100000uF 20V 86F697S 0180 2294 6261B fxd elect 40000uF 50V 32D D42343 DQB 0180 1931 6269B fxd elect 50000uF 50V 36D4512 DOB 0180 2346 C105 6260B fxd elect 100000uF 20V 86F697S 0180 2294 6261B fxd elect 400004F 50V 32D D42343 DOB 0180 1931 T1 62598 power transformer 06259 80091 6260B power transformer 06260 80095 62618 power transformer 06261 80091 6268B power transformer 06268 80091 6269B power transformer 06269 80091 A1 Main PC Board Mechanical barrier strip 13 terminal 0360 1518 barrier strip jumpers qty 4 0360 1143 capacitor clamp C44 1400 0321 A2 Filter Ass y Mechanical 5020 2282 0380 0902 heatsink heatsink mounting standoff 75 rnd qty 4 PC board mounting standoff 625 hex aty 4 washer fiber L1 insulator cover cover standoff 1 hex qty 4 0380 0609 3050 0697 5020 2284 0380 0173 Table 6 4 Replaceable Parts REF DESIG MFG MFG AND MODELS DESCRIPTION PART NUMBER CODE Interconnection Board Mechanical capacitor clamp C3 A4 Heatsink Ass y Mechanical HP PART NUMBER 1400 0472 5020 5769 5020 5769 5020 5764 5020 5763 5020 5793 5020 5763 5
51. AGE ZERO and accessible through hole in rear panel until reading is zero volts 51 Ac o S e CRT am ot eet oie gt o D ZERO o ADJUST o o 0 o RIIS RIIG RUS Figure 5 9 Zero Adjust Section of Main Circuit Board The internal temperature rise of the power supply has an effect on the accuracy of the programming coefficient For example an internal temperature rise of 15 C typical of the temperature difference between no load and full load operation causes the supply output to change by 0 15 Since the factory calibration procedure for instruments equipped with Option 020 or 040 sets the voltage programming coefficient to within 0 156 the resulting accuracy specification including the effect of the 15 temperature rise would be 0 25 5 86 Constant Voltage Programming Accuracy Standard Instrument To calibrate the constant voltage programming current of a standard instrument proceed as follows a Connect 0 1 1 8 watt resistor of value shown below between terminals S and A2 on rear barrier strip Model Value 62598 200022 6260B 20002 6261B 40002 6268B 80009 6269B 80000 b Disconnect strap between terminals A1 and 2 on rear barrier strip c Connect digital voltmeter between OUT and OUT bus bars d Connect decade resistance box in place of R3 mounted on standoffs on main circuit boar
52. IONAL CROWBAR INTERCON NECTIONS SEE PARA 3 72 3 73 Figure 3 14 Auto Tracking Operation of Two Units 3 76 SPECIAL OPERATING CONSIDERATIONS 3 77 Pulse Loading 3 78 The power supply automatically crosses over from constant voltage to constant current operation or the reverse in response to an increase beyond the preset volt age or current limit Although the preset limit may be set higher than the average output current or voltage high peak currents or voltages may exceed the preset limit and cause crossover to occur If this current or voltage limiting is not desired set the current or voltage controls somewhat above the peak rather than the average requirement 3 79 Output Capacitance 3 80 An internal capacitor A3C3 connected across the output terminals of the supply helps to supply high current pulses of short duration during constant voltage operation Adding capacitance externally would improve the pulse current capability of the supply but would decrease the load protection provided by the constant current circuit A high current output pulse could damage load components before the average output current is large enough to cause the constant current circuit to operate Another drawback to adding additional capacitance is the possibility of causing the supply to become unstable and oscillate 3 81 During constant current operation additional capacitance connected across t
53. If this occurs the increased voltage across the series regulator turns 020 on and shuts off the preregulator The conduction of O20 puts R26 in parallel with the current controls to limit the output current to less than 1096 of the supply s rating The preregulator shuts off within 10 milliseconds after the short circuit is imposed Then the input capacitor begins to discharge through the series regulator and the voltage across the regulator decreases until O20 turns off The discharge time typically 1 2 to 4 seconds depends on the voltage and current ratings of the supply the size of the main filter capacitor and the control settings Once this recovery time has elapsed the output current returns to the level set by the current controls and the preregulator returns the voltage across the series regulator to its normal 3 5 volt level 4 33 Constant Voltage Comparator 4 34 The constant voltage comparator consists of programming resistors AbR121 and AbR122 differential amplifier Z1 and associated components An integrated circuit is used for the differential amplifier to minimize FIRING THRESHOLD A TP8O TO ov SUMMING POINT TP85 TO OUTPUT 073 TP89 TO TP86 C FIRING PULSE D 8 2 TO e RESET NOTES 1 ALL WAVEFORMS TAKEN AT MAXIMUM RATED OUTPUT VOLTAGE 230VAC INPUT NO LOAD CONNECTED AND CURRENT CONTROLS FULLY CLOCKWISE 2 SCOPE DC COUPLED 3 FO
54. OINT LOW AC INPUT TO TRANSFORMER Figure 4 3 Triac Phase Control of AC Input Amplitude required to charge C70 The input line voltage is rectified by CR81 CR82 CR83 and CR84 attenuated by voltage divider R83 and R86 and applied to the summing point at the collector of O71 80 via capacitor C70 Capacitor C73 is used for smoothing purposes 4 23 Transistor Q71 connected in a common base con figuration provides a charging current to the summing capacitor which varies with the input signals applied to its emitter Resistor R78 connected between the negative output line and the emitter of Q71 furnishes a signal pro portional to the output voltage Resistors R75 and R76 sample the voltage across and the current through the series regulator Resistors R70 and R80 are the source of constant offset current to the summing point which ensures that the triac will fire at low output voltages Capacitor C72 and resistor R82 stabilize the entire pre regulator feedback loop 4 24 The summation of these input signals results in a voltage waveform at TP80 similar to that shown in wave form A of Figure 4 4 When the linear ramp portion of the waveform reaches a certain negative threshold diodes CR74 and CR75 become forward biased These diodes couple a negative voltage to the base of transistor 072 Transistors O72 and Q73 form a bistable circuit similar to a Schmitt trigger Prior to firing time Q72 is conductin
55. OVERVOLTAGE PROTECTION CROWBAR To avoid false tripping the recommended trip margin above the output voltage is 5 of the output voltage plus 2 voits for Models 6259B 6260B and 6261B and 5 of the output voltage plus 1 volt for Models 6268B and 6269B The approximate crowbar trip voltage ranges are Model Model 62688 4V 45V 62698 4V 45V 6259B 2V 12V 6260B 2V 12V 6261B 2V 23V OPTIONS AVAILABLE See paragraph 1 10 for descriptions All Models Options 005 007 008 009 010 013 014 020 021 022 027 040 Model 6260B only Option 016 Model 6259B 6261B and 6268B Option 026 INPUT POWER CONNECTIONS Input power is connected by way of a 3 terminal barrier strip on the rear panel DIMENSIONS See Figure 2 1 outline diagrams WEIGHT Model Net 78 ths 35 3 kg 106 Ibs 48 0 kg 87 Ibs 39 4 kg 84 Ibs 38 1 kg 98 bs 44 0 kg 6259B 6260B 6261B 62688 6269B 69 15 31 3 kg 97 Ibs 43 9 kg 78 Ibs 35 3 kg 76 Ibs 34 4 kg 89 Ibs 40 3 kg SECTION INSTALLATION 2 1 INITIAL INSPECTION 2 2 Before shipment this instrument was inspected and found to be free of mechanical and electrical defects As soon as the instrument is unpacked inspect for any damage that may have occurred in transit Save all packing materials until the inspection is completed f damage is found file a claim with the carrier immediately The Hewlett Packard Sales and Service office s
56. R CLARITY WAVEFORMS ARE NOT DRAWN TO SCALE Figure 4 4 Preregulator Control Circuit Waveforms voltage differentials due to mismatched transistors or temperature differences 4 35 The constant voltage comparator compares the voltage drop across the VOLTAGE controls with the sup ply s output voltage difference exists it produces an error voltage proportional to this difference This error signal alters the conduction of the series regulator which changes the output voltage until it is equal to the voltage drop across the VOLTAGE controls Hence through feed back action the difference between the two inputs to Z1 is held at zero volts 4 36 One input of the differential amplifier pin 10 is connected to the output voltage sensing terminal of the supply S through impedance equalizing resistor R23 Resistors R1 and optional resistor R110 zero bias the input If the supply is equipped with Option 020 or 040 resistor R114 and rotentiometer R113 provide a variable input bias that allows the output voltage to be easily adjusted to exactly zero volts when the supply is programmed for zero output The other input of the differential amplifier pin 1 is connected to the summing point terminal A2 at the junction of the programming resistors and current pullout resistors R4 and Instantaneous changes in the output voltage or changes in the voltage at the summing point due to changes in the VOLTAGE control setting produce
57. S sensing terminal ACTION TP11 voltage is about 0 7 volts TP11 voltage is about 0 7 volts PROBABLE CAUSE a Q42 open Proceed to step 5 O41 shorted Proceed to step 6 Open sensing lead open strap between A1 and A2 A5R121 122 open CR1 open 21 or Z2 defective Make these tests with external source connected as described in step 3 of Table 5 4 Leave the coarse voltage control set to the center of its range while making these tests Check turn off of error amplifier A4Q101 by momentarily short ing base TP45 to emitter TP100 Check turn off of error amplifier 042 by momentarily shorting base TP44 to emitter TP46 Isolate fault to constant voltage comparator or constant current comparator by opening the cathode of CR20 Check turn on of mixer amplifier O41 by momentarily shorting base 40 to collector 41 Measure the voltage at pin 1 of constant voltage comparator Z1 between TP11and the S sensing terminal Output voltage remains low Output voltage rises Output voltage remains low Output voltage rises Output voltage rises Output voltage remains low Output voltage remains low Output voltage rises TP11 voltage is about 0 7 volts TP11 voltage is about 0 7 volts 512 A4Q101 shorted 40102 open thermal switch A4TS101 open A4Q103 through 40106 A40108 or 40110 o
58. STER 2 4 5 A7 AB S SLAVE 1 DECIDERE Al A2 4 5 7 AB S SLAVE NO 2 Figure 3 11 Auto Parallei Operation of Three Units or the load the current controls of the slave supplies should be set to maximum and the master supply s current controls used to establish the output current or current limit 3 64 Overvoltage Protection in Auto Series The inter connections shown in Figures 3 12 and 3 13 between the external crowbar trigger terminals on the master and on the slave s must be made to permit the overvoltage crowbar in any one of the interconnected supplies to fire the SCRs in all of them if an overvoltage condition occurs Be sure to connect them with correct polar ty plus to plus and minus to minus Set the overvoltage potentiometer in each supply so that it trips at a point slightly above the voltage that supply will contribute 3 65 Auto Series With Remote Sensing To combine auto series operation with remote sensing connect the supplies as described above but remove the S jumper from the master supply and the S jumper from the last slave supply and connect the S and 5 terminals directly to the and ends of the load Observe the precautions outlined under paragraph 3 27 3 66 Auto Series With Remote Programming When two or three supplies are connected in auto series their combined output voltage current or bot
59. T controls fully clockwise d Turn on supply and adjust VOLTAGE controls unti front panel meter indicates exactly maximum rated output voltage e Digital voltmeter should indicate 62598 62608 10 0 2Vdc 6261B 20 0 4Vde 6268 62698 40 0 8Vdc 5 11 Load Effect Load Regulation Definition The change AEouT in the static value of dc output voltage resulting from a change in load resistance from open circuit to a value which yields maximum rated output current or vice versa 5 12 To check the constant voltage load effect proceed as follows a Connect test setup shown in Figure 5 1 b Turn CURRENT controls fully clockwise c Turn on supply and adjust VOLTAGE controls until front pane meter indicates exactly maximum rated output current d Read and record voltage indicated on digital voltmeter e Disconnect load resistor f Reading on digital voltmeter should not differ from reading recorded in step d by more than 6259 62608 1 2mV 62618 2 2mV 62688 6269B 4 2mV RL 5 o2Q 0 40 1 332 0 82 POWER SUPPLY UNDER TEST 500W 1000W 1000W 1200W 2000w DIGITAL VOLTMETER Figure 5 1 Constant Voltage Load Regulation Test Setup 5 13 Source Effect Line Regulation Definition change AEour in the static value of dc output voltage resulting from a change in ac input voltage over the specified range from low line to high line or from high line to low line 5 14 To
60. TION Constant Voltage Less than 0 01 of output plus 200uV for a load change equal to the current rating of the supply Constant Current Models 6259B and 6261B Less than 0 02 of output plus 1mA for a load change equal to the voltage rating of the supply Models 62608 6268B and 6269B Less than 0 02 of output plus 2 for a load change equal to the voltage rating of the supply SOURCE EFFECT LINE REGULATION Constant Voltage Less than 0 01 of output plus 200 for a change in line voltage between 208 and 254 Vac or 104 and 127Vac at any output voltage and current within rating Constant Current Models 6259B and 6261B Less than 0 0296 of output plus 1mA for a change in line voltage between 208 and 254Vac 104 and 127 Vac at any output voltage and current within rating Models 6260B 6268B and 6269B Less than 0 0276 of output plus 2 for a change in line voltage between 208 and 254Vac 104 and 127 Vac at any output voltage and current within rating PARD RIPPLE AND NOISE Measured within 20Hz to 20MHz bandwidth Model Constant Voltage Constant Current 25mA rms 50mA rms 25mA rms 20mA rms 25mA rms 6259B 6260B 62618 6268B 6269B 500uVrms 5mV 500uVrms 5mV 500uVrms bmV 1mVrms 5mV p p 1mVrms 5mV TEMPERATURE COEFFICIENT Constant Voltage Less than 0 01 plus 200uV change in output per degree Celsius change in ambient following 30
61. UMBER MFG PART NUMBER REF DESIG AND MODELS DESCRIPTION 0107 108 6260B power NPN Si 2N3771 1854 0245 6269B power NPN Si 60675 02735 1854 0458 0109 10 62608 power Si 2N3771 1854 0245 R106 6259B 60B 618 fxd ww 0 1 15 obd 89663 0811 3080 6268B 69B fxd ww 0 2 1596 obd 0811 3081 R123 6259B 61B 69B fxd ww Cupron 01 20ppm 28480 5080 7144 6268B fxd ww Cupron 0167 20ppm 06268 80001 R123A 123B 62608 fxd ww Cupron 01 20ppm 28480 5080 7144 R150 153 fxd ww 0 1 5 8W 0811 2545 R154 155 62598 60B 61B 69B fxd ww 0 1 5 8W 0811 2545 R156 157 6259B 60B 61B fxd ww 0 1 5 8W 0811 2545 R158 165 6260B fxd ww 0 1 5 8W 0811 2545 TS101 switch thermal opens 230 F 430 632 0440 0079 5 Front Panel Electrical 0160 2568 C110 112 fxd O1UF 3kV 41C121A5 CDH CBI 62598 60B 61 68B circuit breaker 20A 250Vac 2 pole AM2 A3 A 20 2 74193 3105 0035 6269B circuit breaker 25A 250Vac 2 pole 2 25 3 74193 3105 0034 DSi LINE ON indicator light neon 28480 1450 0566 DS2 OVERVOLTAGE indicator light MCL A3 1730 07137 1450 0305 M1 62598 60B voltmeter 0 12Vdc 28480 1120 1170 6261B voltmeter 0 24 Vdc 28480 1120 1171 626
62. V fxd elect 4 7uF 35V fxd elect 325uF 35V fxd elect 35V fxd polyester 0 22uF 80V fxd elect 5uF 50V fxd cer 0 47 25V fxd polyester 4700pF 200V diode Si 200mA 180V diode Si 3 junction diode Si 200mA 180V not used diode Si 200mA 180V diode Si 1A 200V diode Si 200mA 180V SS PNP Si SS NPN Si SS PNP Si SS PNP Si SS NPN Si SS PNP Si SS NPN Si SS PNP Si SS NPN Si fxd film 1M 196 1 4W fxd comp 39 5 1 2W fxd 82 5 1 2W fxd comp 160 5 1 2W fxd comp selected 596 1 2W fxd ww 680 5 5W ww 600 5 5W fxd ww 680 5 5W 192P10392 30D505G050BB2 150D686X0015R2 30D206G050C02 192P22392 192P22392 192P10392 1500475 9035 2 D34656 DEE 150D105X9035A2 AE22R224KT 30D505G050BB2 5C11B7 CML 292P47292 1N485 STB 523 1N485 1N485 1N5059 1N485 TZ 173 2N3391 TZ 173 2N4036 2N3391 TZ 173 2N3391 TZ 173 2N3391 CEB T 0 EB 3905 EB 8205 EB 1615 EB 243E6815 243E6015 243E6815 REF DESIG MFG MFG HP AND MODELS DESCRIPTION PART NUMBER CODE PART NUMBER 0160 0161 0180 0301 0180 1835 0180 0049 0160 0162 0160 0162 0160 0161 0180 1860 0180 0100 0180 0332 0180 0291 0160 2453 0180 0301 0160 0174 0160 0157 1901 0033 1901 0460 1901 0033 1901 0033 1901 0327 1901
63. a and Instrument Corp 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 III Union Carbide Corp Electronics Div Mountain View Calif UID Electronics Corp Hollywood Fla Pamotor Inc Pampa Texas General Electric Schenectady N Y General Electric Co 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 Hewlett Packard Co Palo Alto Calif Heyman Mfg Co Kenilworth N J IMC Magnetics Corp Rochester N H SAE Advance Packaging Inc Santa Ana Calif Ramona Calif Owensboro Ky Chicago III Budwig Mfg Co G E Co Tube Dept Lectrohm Inc P R Mallory amp Co Indianapolis Ind Muter Co Chicago Hi New Departure Hyatt Bearings Div General Motors Corp Sandusky Ohio Ohmite Manufacturing Co Skokie Penn Engr and Mfg Corp Doylestown Polaroid Corp Cambridge Mass Raytheon Co Lexington Mass Simpson Electric Co Div of American Gage and Machine Co Chicago Ill Sprague Electric Co North Adams Mass Superior Electric Co Bristol Conn Syntron Div of FMC Corp Homer City Pa 6 3
64. ain the 12 4 volt output at a constant level 4 64 Diode CR60 connected from voltage divider R66 and R67 to the base of Q61 serves as a turn on circuit for series regulator transistor O60 When the supply is first turned on CR60 biases driver Q61 on thus turning on the series regulator When the reference supply reaches normal output the base voltage of Q61 is sufficient to reverse bias CRGO thus effectively removing it from the circuit Capa citor C60 connected across the output of the reference sup ply removes spikes and stabilizes the reference regulator loop 4 65 A separate winding on transformer A3T2 diodes CR53 and CR54 and filter capacitor C44 provide un regulated 11V output Additional lightly regulated refer ence voltages of 2 4 volts and 4 volts are provided by diodes CR45 through CR49 Resistor R41 biases the diodes Diode CR43 prevents reverse current flow from damaging the main supply series regulator transistor s Diode CR7 shown on the schematic near current pullout resistors R3 R4 and R5 protects the zener diodes in the reference cir cuit by providing a path for surge currents that occur during rapid down programming 4 66 Meter Circuit 4 67 The front panel voltmeter and ammeter provide continuous indications of output voltage and current Both meter movements can withstand an overload of several times the maximum rated output without damage 4 68 The ammeter together with its series r
65. al voltmeter as illustrated in Figure 5 1 b Turn CURRENT controls fully clockwise c Turn on supply and adjust front panel VOLTAGE controls until digital voltmeter indicates maximum rated output voltage d Allow 30 minute warm up then record digital voltmeter reading e After 8 hours digital voltmeter reading should not differ from the step d reading by more than 6259B 62608 5 6261 62688 8 62698 14mV 5 38 CONSTANT CURRENT TESTS 5 39 The instruments methods and precautions for the proper measurement of constant current power supply characteristics are for the most part identical to those already described for the measurement of constant voltage characteristics There are however two main differences First the power supply performance will be checked between short circuit and full load rather than open circuit and full load Second a current monitoring resistor is inserted between the output of the power supply and the load 5 40 For all output current measurements the current sampling resistor must be connected as a four terminal device in the same manner as a meter shunt would be The load current is fed to the extremes of the wire leading to the resistor while the sampling terminats are located as close as possible to the resistance element itself see Figure 5 6 A current sampling resistor should have low noise low temperature coefficient less than 30ppm C and should be used at no more th
66. am the supply The constant current programming coefficients for the supplies included in this manual are as follows 51096 Model 62598 10 0mV ampere 6260B 5 0mV ampere 6261B 10 0mV ampere 6268B 16 7mV ampere 6269B 10 0mV ampere EXT CROWBAR TRIGGER EA 2 A3 4 5 A7 AB S 2210129 2 ole PROGRAMMING RESISTOR Figure 3 7 Resistance Programming of Output Current 3 7 The load on the programming voltage source is less than 20 microamperes The programming voltage required to obtain maximum rated current from these supplies is about 500 millivolts An input greater than 600mV may damage the instrument through excessive power dissipation Impedance matching resistor Rx is required to maintain the temperature Coefficient and stability specifications of the supply To adjust the output current to exactly zero with a zero pro gramming voltage follow the same instructions as are referred to in paragraph 3 46 3 48 Constant Current Output Voltage Input Variable Gain In the remote programming arrangement shown in Figure 3 9 the series combination of external voltage source and reference resistor Rn replaces the supply s internal current programming source As a result the volt age this external current source develops across gain control Rp becomes the reference against which the voltage drop across the output current sampling resistor is compared by the constant cur
67. an 5 of its rated power so that its temperature rise will be minimized NOTE In case of difficulty obtaining a low resis tance high current resistor suitable for current sampling a duplicate of the sampling resistor used in this unit A4R123 or A4R123A and A4R123B may be obtained from the factory 5 41 Current Output and Ammeter Accuracy To check that the supply will furnish its rated output current pro ceed as follows a Connect test setup shown in Figure 5 7 b Turn VOLTAGE controls fully clockwise Turn on supply and adjust CURRENT controls until front pane ammeter indicates maximum rated output current d Digital voltmeter should read 0 5 0 01 Vdc 5 42 Load Effect Load Regulation Definition The change Alout in the static value of the dc output current resulting from a change in load resistance from short circuit to a value which yields maximum rated output voltage or vice versa CURRENT SAMPLING TERMINALS TO UNGROUNDED Rs TERMINAL OF A SAMPLING RESISTOR LOAD TERMINALS TO GROUNDEO TERMINAL OF POWER SUPPLY POWER SUPPLY Figure 5 6 Current Sampling Resistor Connections 5 7 5 43 To check the constant current load effect proceed as follows a Connect test setup shown in Figure 5 7 b Turn VOLTAGE controls fully clockwise c Turn on supply and adjust CURRENT controls until front panel ammeter indicates exactly maximum rated output current d Read and record voltage ind
68. as an external resistor Rx associated with it that supplies its voltage programming current If the temperature coefficient and stability specifications of the supplies are to be maintained these must be stable low noise resistors with a temperature coefficient of less than 30ppm per C and a power rating at least 30 times what they will actually dissipate The proper value for Rx when using two units in auto series or for for the first slave when using three units is calculated by first finding the voltage pro gramming current of the slave supply This is calculated by referring to Table 1 1 for the remote voltage programming resistance control coefficient and taking its reciprocal For example the voltage programming current in the Model 62598 is 1 2002 V or 5mA Next divide this current into the maximum voltage rating of the master supply to determine Rx for the first slave If our master supply were a zero to 25 volt unit for example Rx or Ry would be 25V 5mA 5000 ohms 3 61 When operating three supplies in auto series find Ryo by dividing the voltage programming current of the second slave calculated as in paragraph 3 60 into the maximum voltage expected from the first slave 3 62 Setting the Voltage Controls The voltage each slave supply contributes is determined by its voltage control setting The output voltage of the first slave supply tracks the voltage of the master and the voltage of the second slave if used
69. b Remote Sensing Connecting the voltage regulator s feedback circuit to the load terminals rather than to the supply s output terminals prevents the voltage drop in the load leads from impairing voltage regulation at the load when operating in the constant voltage mode separate pair of sensing leads which carry no load current extend the feedback loop to the load terminals c Auto Parallel Operation Two or three similar supplies connected in parallel can be made to share loads equally and can be controlled by the voltage and current controls or remote programming terminals of one of the supplies designated the master if they are connected for auto parallel operation Normally only supplies having the same model number are connected in auto parallel but auto parallel operation can be used with any of the supplies covered by this manual that have equal current capabilities d Auto Series Operation Two or three supplies can be connected in series and have their outputs simultaneously controlled by the voltage and current controls or remote programming terminals of one of the supplies designated the master The voltage contributed by each slave is main tained in a constant ratio to that of the master These ratios can be set as desired Auto series operation provides higher output voltages in constant voltage operation and greater voltage compliance in constant current operation Any HP supply that offers auto series operation can serve
70. be controlled through a voltage input When voltage program ming the output voltage the choice can be made between using a connection that produces a unity gain relationship between input and output paragraph 3 41 or another connection that produces variable voltage gains paragraph 3 42 Similarly the output current can be programmed using a connection that produces a fixed gain paragraph 3 47 or a variable gain paragraph 3 48 3 37 Connecting a supply for remote voltage or current programming disables the corresponding front panel controls 3 38 The following paragraphs discuss in greater detail the methods of remotely programming the output voltage or current using either a resistance or a voltage input Whichever method is used the wires connecting the pro gramming terminals of the supply to the remote program ming device must be shielded to reduce noise pickup The outer shield of the cable should not be used as a conductor but should be connected to ground at one end only 3 39 Constant Voltage Output Resistance Input The rear panel connections shown in Figure 3 4 allow the out put voltage to be varied by using an external resistor to program the supply The supply s constant voltage program ming current determines its programming coefficient In the supplies covered by this manual this programming current is factory adjusted to within 1 of 5mA resulting in a programming coefficient of 200 ohms per volt greater
71. check the source effect proceed as follows a Connect test setup shown in Figure 5 1 b Connect variable autotransformer between input power source and power supply ac input c Adjust autotransformer for 208Vac input d Turn CURRENT controls fully clockwise e Turn on supply and adjust VOLTAGE controls until front panel meter indicates exactly maximum rated output voltage f Read and record voltage indicated on digital volt meter g Adjust variable autotransformer for 254Vac input h Digital voltmeter reading should not differ from reading recorded in step f by more than 6259B 62608 1 2mV 62618 2 2mV 6268 62698 4 2mV 5 15 Ripple and Noise Definition The residual ac voltage superimposed on the dc output of a regulated power supply Ripple and noise measurements may be made at any input ac line voltage combined with any dc output voltage and load current within the supply s rating 5 16 The amount of ripple and noise present on the power supply output is measured either in terms of its rms or preferably peak to peak value The peak to peak measurement is particularly important for applications where noise spikes could be detrimental to sensitive loads such as logic circuitry The rms measurement is not an ideal representation of the noise since fairly high output noise spikes of short duration can be present in the ripple without appreciably increasing the rms value 5 17 Ripple Measurement Techn
72. d see Figure 7 7 e Rotate CURRENT controls fully clockwise and turn on supply f Adjust decade resistance box until digital voltmeter indicates exactly maximum rated output voltage g Replace decade resistance box with fixed composi tion 596 1 2 watt resistor of same value 5 87 Constant Voltage Programming Accuracy Option 020 Instrument To calibrate the constant voltage pro gramming current of an Option 020 instrument proceed as follows a Perform steps a through c of paragraph 5 86 b Rotate CURRENT controls fully clockwise and turn on supply c Adjust potentiometer R112 labeled VOLTAGE PROG and accessible through hole in rear panel until digital voltmeter indicates exactly maximum rated output voltage 5 88 Constant Voltage Programming Accuracy Option 040 Instrument To calibrate the constant voltage pro gramming current of an Option 040 instrument proceed as follows a Connect 0 1 1 8 watt resistor of value shown below between terminals S and A2 on rear barrier strip Model Value 6259B 20100 62608 20102 6261B 40102 6268B 80109 6269B 80100 b Disconnect strap between terminals A1 and A2 on rear barrier strip c Connect digital voltmeter between OUT and OUT bus bars d Rotate CURRENT controls fully clockwise and turn on supply e Adjust potentiometer R112 labeled VOLTAGE and accessible through hole in rear panel until digital voltmeter indicates full rat
73. d Rated Output 3 23 The supply may be able to provide voltages and currents greater than its rated maximum outputs Operation can extend into the shaded areas on the meter face without damage to the supply but performance cannot be guaranteed to meet all specifications 3 24 OPTIONAL OPERATING MODES 3 25 The optiona operating modes discussed in the following paragraphs include a Remote voltage sensing b Remote programming c Auto Paralle operation d Auto Series operation e Auto Tracking operation Special operating instructions for instruments equipped with Option 040 to permit their interfacing with a Model 6940B Multiprogrammer or a 6941B Multiprogrammer Extender are not included but can be found in the manual covering the programmable resistance cards that are neces sary to complete the interface Special calibration instruc tions for power supplies equipped with Option 040 are included in Section V of this manual 3 26 By changing its rear pane strapping pattern according to the instructions which follow any of the supplies covered by this manua can be operated in any of the modes listed above CAUTION Disconnect input ac power before changing any rear panel connections and make certain all wires and straps are properly connected and terminal strip screws are securely tightened before reapplying power 3 27 Remote Voltage Sensing 3 28 Because of the unavoidable voltage drop developed
74. ded the supply automatically crosses over to constant current operation at this preset current limit and the output voltage drops proportionately In setting the current limit make an adequate allowance for high peak currents that could cause unwanted crossover Refer to paragraph 3 77 3 10 Constant Current Operation 3 11 To adjust the supply for constant current operation a Connect a short across the rear output terminals turn the power on and adjust the CURRENT controls for the desired output current b Open the output terminals and adjust the VOLTAGE controls for the desired maximum output voltage Ifa load change causes this voltage limit to be exceeded the supply automatically crosses over to constant voltage opera tion at this preset voltage limit and the output current drops proportionately In setting the voltage limit make an adequate allowance for high peak voltages that could cause unwanted crossover Refer to paragraph 3 77 3 12 Overvoltage Trip Point Adjustment 3 13 The crowbar trip voltage is adjusted by using the screwdriver control on the front panel The approximate trip voltage ranges are listed in Table 1 1 When the crowbar trips an SCR shorts the output and the amber OVER VOLTAGE indicator on the front panel lights Rotating the control clockwise sets the trip voltage higher It is set to maximum at the factory Paragraph 5 108 contains instruc tions for completely disabling the crowbar if this is de
75. e 3 2 and turn it back on h Adjust COARSE and FINE CURRENT controls until ammeter indicates desired output current or current limit The VOLTAGE controls must be set for a greater than zero output to obtain the output current programmed i Turn off the supply remove the short from its out put and read the remainder of these operating instructions before connecting the supply to an actual load 33 OPERATING MODES 3 4 This power supply is designed so that its mode of operation can be selected by making strapping connections between terminals on its rear panel The following para graphs first describe normal operation using the normal strapping pattern as it is connected at the factory Later paragraphs cover some optiona operating modes including remote voltage sensing remote programming and some methods of operating these power supplies in combinations of two or three 3 5 The DC Power Supply Handbook Application Note is a useful source of additional information on using regulated power supplies effectively This 138 page handbook includes chapters on operating principles ac and load connections optional operating modes and performance measurements and is available at no charge from your local HP sales office The address of your local sales office can be found in the back of this manual 3 6 NORMAL OPERATING MODE 3 7 This power supply was shipped with the proper rear panel strapping connections made for con
76. e achieved 5 29 We suggest that a mercury wetted relay connected in the load switching circuit shown in Figure 5 4 be used for loading and unloading the supply When this load switch is connected to a 60Hz ac input the mercury wetted relay opens and closes 60 times per second The 25k con trol adjusts the duty cycle of the load current switching to reduce jitter in the oscilloscope display This relay may also be used with a 50Hz ac input The load resistance shown in Figure 5 4 is the minimum resistance that can be used without damaging the mercury wetted relay contacts 5 30 Measurement Procedure To check the load transient recovery time proceed as follows a Connect test setup shown in Figure 5 4 b Turn CURRENT controls fully clockwise c Turn on supply and adjust VOLTAGE controls until front panel ammeter indicates either 5 amps or the full toad current rating of the supply whichever is less d Close line switch on repetitive load switch setup e Set oscilloscope for internal sync and lock on either the positive or negative load transient spike 5 5 f Set vertical input of oscilloscope for ac coupling so that small dc level changes in power supply output voltage will not cause display to shift 9 Adjust the vertical centering on the scope so that the tail ends of the no toad and waveforms are sym metrically displaced about the horizontal centerline of the oscilloscope This centerline now represe
77. e to be used Once the value for is selected multiply by the maximum voltage gain desired to find Rp 1f desired the power supply s front panel voltage controls can be used in place of external gain control Rp by deleting the external gain control from the circuit and strapping together terminals A1 and A2 344 The output voltage of the supply can be adjusted to exactly zero with a zero programming voltage input either by installing and adjusting R111 as discussed in paragraph 5 82 or if the instrument is equipped with Option 020 or 022 by adjusting potentiometer R112 as discussed in paragraph 5 83 345 Constant Current Output Resistance Input The rear panel connections shown in Figure 3 7 allow the output current to be varied by using an external resistor to program the supply The supply s constant current program ming current which is factory adjusted to 2 5mA 10 determines the exact value of its programming coefficient The programming coefficients for the supplies included in this manual are as follows Models 6259B 4 ohms ampere 6260B 2 ohms ampere 6261B 4 ohms ampere 6268B 6 ohms ampere 6269B 4 ohms ampere If the 10 accuracy of these coefficients is not adequate they may be adjusted either by changing resistor R30 as discussed in paragraph 5 96 or if the instrument is equipped with Option 021 or 022 by adjusting potentiometer R116 as discussed in paragraph 5 97 EXT CROWBAR TRIGGER f
78. e voltage across its own load Then if the master supply crowbars the output voltage of the slave s also decreases but if one of the slaves crowbars no other supply is affected 3 73 In order to have all supplies in an auto tracking combination crowbar simultaneously if any of them has an overvoltage condition parallel their crowbar circuits as shown in Figure 3 14 or 3 15 Set the overvoltage poten tiometer in each supply so that it trips at a point slightly above the voltage that supply will provide 3 74 Auto Tracking With Remote Sensing To combine auto tracking operation with remote sensing connect the supplies as described above but remove the S and S jumpers from each supply and connect the S and S terminals directly to the and ends of its load Observe the precautions outlined under paragraph 3 27 3 75 Auto Tracking With Remote Programming When two or three supplies are connected for auto tracking opera tion their output voltages can be remotely programmed but their currents cannot Refer to the appropriate sections of paragraph 3 34 for the additional rear panel connections required and make these connections to the master supply only Observe all precautions outlined in the paragraphs on remote programming The simultaneous use of remote sensing and remote programming is also possible during auto tracking operation EXT CROWBAR TRIGGER 2 A4 5 AG A7 8 S S A9 MASTER OPT
79. ective diode CRp in series with the battery as shown in Figure 3 16 to prevent the battery from dis charging into the supply if the supply is turned off Extensive damage to the supply could result if this diode were omitted The use of remote voltage sensing provides no advantages when performing a constant current battery charge as discussed in paragraph 3 89 or a taper charge as discussed in paragraph 3 90 Because of a serious risk of damage to the supply the use of remote voltage sensing should not be attempted when charging or discharging a battery Also see the CAUTION following paragraph 3 32 NOTE A large battery connected as a load presents a large capacitance to the output terminals This capacitance could cause the supply to oscillate If the supply appears unstable it may be beneficial to readjust equalization control R47 located on the main circuit board 3 89 Constant Current Charge To perform a constant current battery charge set the charging rate and full charge voltage as follows Turn both the VOLTAGE and CURRENT controls fully counterclockwise CCW b Connect a short circuit across the output terminals and rotate the VOLTAGE control fully clockwise CW c Adjust the CURRENT control for the desired charging rate as read on the front panel ammeter d Rotate VOLTAGE control fully CCW and remove the short circuit e Adjust the VOLTAGE control for an output voltage 0 7 volts greater than the des
80. ed output voltage 0 1 5 89 Constant Current Programming Calibration 5 90 To calibrate the zero current programming accuracy proceed as directed in paragraph 5 91 5 92 5 93 5 94 or 5 95 whichever applies to your particular instrument To calibrate the constant current program ming accuracy proceed as directed in paragraph 5 96 or 5 97 5 91 Zero Output Current Standard Instrument With Resistance or Fixed Gain Voltage Programming For instruments using either local programming or the remote programming setup shown in Figure 3 7 or 3 8 zero the output current as follows a Connect test setup shown in Figure 5 7 b If unit is to be used in local programming mode turn CURRENT controls fully counterclockwise If unit is to be used in remote programming mode connect remote programming setup and adjust remote resistance or voltage to zero Connect decade resistance box between pads in zero adjust section of A1 main circuit board that are marked and H in Figure 5 9 These pads are for R117 d Rotate VOLTAGE controls fully clockwise and turn on supply e Adjust decade resistance box until digital voltmeter reads exactly zero volts f Replace decade resistance box with fixed metal film 196 1 4 or 1 8 watt resistor of same value 5 92 Zero Output Current Standard Instrument With Variable Gain Voltage Programming For instruments using the remote programming setup shown in Figure 3 9 zero the output curr
81. een properly corrected and that no other faults exist Before performing any maintenance checks turn on the power supply and allow a half hour warm up 5 1 INTRODUCTION 5 2 Upon receipt of the power supply the performance test paragraph 5 5 should be made This test is suitable for incoming inspection fault is detected in the power supply while making the performance test or during normal operation proceed to the troubleshooting procedures paragraph 5 49 After troubleshooting and repair Digital Voltmeter Oscilloscope Variable Voltage Transformer Digital or Analog Multimeter Repetitive Load Switch Resistive Load Current Sampling Resistor Terminating Resistors Blocking Capacitors Table 5 1 Test Equipment Required REQUIRED CHARACTERISTICS Sensitivity 100 full scale min Input Impedance 10MQ min Sensitivity and bandwidth 100u V cm and 400kHz for all measurements except noise spike 5mV sensitivity and 20MHz bandwidth for noise spike measurement Range 208 254 volts Output current 20096 min of supply input current listed in para 2 16 Switching rate 60 400Hz Rise time 2usec Values see Figures 5 1 5 4 and 57 Value See Figure 5 7 Value 50 ohms 1 2 watt 5 non inductive Four required Value 0 01uF 100Vdc Two required 51 Measure dc voitages calibration procedures Measure ripple display transient recovery waveform measu
82. en it is shipped from the factory The supplies covered by this manual are also available equipped for a 208 volt input Option 027 and except for the Model 6269B are also available equipped for a 115 volt input Option 026 for Models 6259B 6261B and 6268B or Option 016 for the Model 6260B In addition all five models are available in a 50Hz version The input voltage and frequency required is marked on the rear panel of the supply Except for the Model 6269B which cannot be converted to 115 volt operation a standard instrument can be converted by the user to 208 or 115 volt and to 50Hz operation by following the instructions given in the follow ing paragraphs The standard instrument requires the input current and power listed below when operated at full load from a 230 volt source When the supply is operated from a 115 volt source the input current is approximately twice the amount listed Model Input Current Input Power 6259B 6A 850W 62608 12 1600W 6261B 12A 1500W 6268B 12A 1600W 62698 18 2500W 2 17 INPUT LINE VOLTAGE OR FREQUENCY CONVERSION 2 18 Converting a 230 volt instrument to 208 volt operation is simply a matter of changing some taps or jumper connections on main power transformer T1 and bias transformer A3T2 Converting to 115 volt operation is more involved The Models 6259B 6260B 6261B and 62688 require an added resistor and some jumper changes in the A2 assembly and a changed A3T2 transformer tap
83. ency spikes that could be detrimental to the load 5 25 The test setup illustrated in Figure 5 2 is generally not adequate for measuring spikes a differential oscilloscope is necessary Furthermore the measurement technique of Figure 5 2B must be modified as follows if accurate spike measurement is to be achieved 1 As shown in Figure 5 3 two coax cables must be substituted for the shielded two wire cable 2 Impedance matching resistors must be included to eliminate standing waves and cable ringing and capacitors must be connected to block dc current 3 The length of the test leads outside the coax is critical and must be kept as short as possible The blocking capacitor and impedance matching resistor should be connected directly from the inner conductor of the cable to the power supply sensing terminal 4 Notice that the shields at the power supply end of the two coax cables are not connected to the power supply ground since such a connection would give rise to a ground current path through the coax shield and result in an erroneous measurement son TERMINATION POWER SUPPLY T CONNECTOR OSCILLOSCOPE CASE CASE S zu at gt VERTICAL INPUT son i TERMINATION T CONN CTOR Figure 5 3 Noise Spike Measurement Test Setup 5 Since the impedance matching resistors constitute a 2 to 1 attenuator the noise spikes observed on the oscillo scope should be less than
84. ent falls to zero biasing Q70 on When Q70 conducts it disables the preregulator by holding CR74 and CR75 reverse biased to prevent Q72 and O73 from generating triac firing pulses 4 29 Series Regulator and Driver 4 30 Depending on the model the series regulator is composed of four six or eight transistors connected in parallel These transistors serve as the series element that provides precise and rapid control of the output The series transistors are controlled by driver 40102 Thermal switch 475101 turns off the series regulator transistors by opening if the heatsink temperature exceeds approxi mately 230 F This feature protects critical components from the excessive temperatures that could occur if cooling fan 4 1 failed Diode CR50 provides a discharge path for the output capacitors when the supply is rapidly down programmed Resistor R57 limits the discharge current through the diode and through error amplifier 40101 Diode A4CR105 is connected across the regulator circuit to protect the series elements from reverse voltages that could develop if one supply is turned on or off before the other during parallel operation 4 31 Short Circuit Protection 4 32 The short circuit protection circuit protects the 44 series regulator against damage due to a simultaneous full voltage full current condition as might occur if the output were shorted while the controls were set to deliver a high output voltage and current
85. ent as follows a Perform steps a and b of paragraph 5 91 b Solder a jumper between pads in zero adjust section of Al main circuit board that are marked I and J in Figure 5 9 c Connect decade resistance box between pads marked K and L in Figure 5 9 These pads are for R115 d Perform steps d through f of paragraph 5 91 5 93 Zero Output Current Option 021 Instrument With Resistance or Fixed Gain Voltage Programming For Option 021 instruments using either local program ming or the remote programming setup shown in Figure 3 7 or 3 8 zero the output current as follows a Perform steps a and b of paragraph 5 91 b Rotate VOLTAGE controls fully clockwise and turn on supply c If reading on digital voltmeter is not exactly zero volts adjust potentiometer R119 labeled CURRENT ZERO and accessible through hole in rear panel until reading is exactly zero 5 94 Zero Output Current Option 021 Instrument With Variable Gain Voltage Programming For Option 021 instruments using the programming setup shown in Figure 3 9 zero the output current as follows a Perform steps a and b of paragraph 5 91 b Rotate VOLTAGE controls fully clockwise and turn on supply If reading on digital voltmeter is not exactly zero volts adjust potentiometer R116 labeled CURRENT PROG and accessible through hole in rear panel until reading is exactly zero 5 95 Zero Output Current Option 040 Instrument
86. es 5 5 5 6 or 5 7 5 57 Tables 5 5 5 6 and 5 7 contain troubleshooting procedures for the series regulator and preregulator feed back loops once the fault has been isolated to one of them Tables 5 5 and 5 6 contain instructions for driving each stage into conduction or cut off By following the steps in these tables the fault can be isolated to a circuit or a component 5 58 Table 5 7 contains troubleshooting procedures for the preregulator feedback loop Troubleshooting is accomplished by comparing waveform illustrations with the waveforms found at various test points and then checking the components most likely to be at fault 5 59 After troubleshooting the unit it may be necessary to perform one or more of the calibration procedures given in this section WARNING Some circuits in this power supply are connected directly to the input ac power line The red painted case and heatsink of the A2 RFI Assembly are also at ac line potential Exercise extreme caution when working on energized circuits Table 5 2 Reference and Bias Voltages Refer to schematic and component location diagrams in Section VII for test point locations METER METER COMMON POSITIVE STI 824 2 5 u E 9 NORMAL RIPPLE P P PROBABLE CAUSE TP66 USES CR53 CR54 CR53 CR54 C44 CR45 49 4 0 12 5 CRS3 CR54 C44 CR45 49 2 4 112 5
87. esistors R101 and R105 is connected across current sampling resistor A4R123 As mentioned previously the voltage drop across A4R123 varies in proportion to the output current Poten tiometer R101 permits calibration of the ammeter 4 69 The voltmeter in series with 103 and R104 and shunted by R102 and R106 is connected directly across the output terminals of the supply Potentiometer R106 permits calibration of the voltmeter 4 70 Additional Protection Features 4 71 The supply contains several special purpose com ponents that protect it in the event of unusual circumstances One of these components is diode A4CR106 and A4CR107 Connected across the output terminals of the supply it prevents internal damage from reverse voltages that might be applied across the supply This could occur for example during Auto Series operation if one supply were turned on or off before the other 4 72 Resistors R108 and R109 limit the output of the supply if the jumpers between the output buses and the sensing terminals S and S are inadvertently removed 4 73 Diode A4CR105 previously mentioned in the series regulator description protects the regulating transistor from reverse voltages SECTION V MAINTENANCE paragraph 5 69 perform any necessary adjustments and calibrations paragraph 5 71 Before returning the power supply to normal operation repeat the applicable portions of the performance test to ensure that the fault has b
88. eter remains outside oven Set temperature to 30 and allow 30 minute warm up e Record digital voltmeter reading f Raise temperature to 40 and allow 30 minute warm up g Observe digital voltmeter reading Difference in voltage reading between steps e and g should be less than 6259B 62608 12mV 62618 22mV 6268B 6269B 42mV 5 35 Drift Stability Definition The change in output voltage for the first eight hours following a 30 minute warm up period During the interval of measurement input line voltage load resis tance and ambient temperature are al held constant 5 36 This measurement is made by monitoring the output of the power supply on a digital voltmeter over the stated measurement interval A strip chart recorder can be used to provide a permanent record Place a thermometer near the supply to verify that the ambient temperature remains constant during the period of measurement The supply should be located away from any source of stray air currents If possible place the supply in an oven and hold it at constant temperature Take care that the measuring instrument has an eight hour stability at least an order of magnitude better than the stability specification of the power supply being tested Typically a supply will drift less over the eight hour measurement interval than during the half hour warm up 5 37 To check the output stability proceed as follows a Connect load resistance and digit
89. ews holding upper edge of heat sink to upper chassis flange marked A in Figure 7 4 d Disengage two pins holding lower section of heat sink assembly to main circuit board support tray by sliding heat sink down about 1 2 inch and slightly away from chassis Before fully removing heat sink assembly Observe lead dress so assembly may be returned easily to Correct position e Maneuver heat sink assembly downwards and away from chassis until it is resting on table sufficient lead length is provided Gentle leverage with a thin screw driver may be necessary to allow heat sink assembly to clear upper chassis flange Access is now provided to all components mounted on heat sink except resistors A4R150 through A4R165 and A4R123 5 67 A4 Heat Sink Disassembly To gain access to resistors A4R123 and A4R150 through A4R165 it is necessary to disassemble the heat sink assembly as follows a Remove heat sink assembly as described in paragraph 5 66 above b Turn suppty upside down and place heat sink assembly partially into chassis so fan 4 1 is protruding above chassis c Remove four screws and four shoulder washers attaching fan mounting plate to heat sink Do not remove fan from mounting plate When reassembling heat sink do not overtighten these screws Too much tension will damage the insulating rods d Remove two screws holding current sampling resistor A4R123 to heat sink f necessary the resistor may be unsoldered a
90. g High Output Voltage Make these tests with external source connected as described in step 3 of Table 5 4 Leave the coarse voltage control set to the center of its range while making these tests Check turn off of series a Output voltage remains One or more of A4Q103 through A4Q106 regulator transistors A4Q103 high A4Q108 or A4Q110 shorted or AACR105 through 40106 40108 or shorted Check A4R150 A4R165 as A40110 by momentarily applicable shorting base TP101 to emitter Output voltage Proceed to step 2 TP103 decreases Check turn off of driver Output voltage remains 40102 shorted A40102 by momentarily high shorting base TP100 to Output voltage Proceed to step 3 emitter TP101 decreases Check turn on of error Output voltage 40101 open amplifier 40101 by high momentarily shorting O42 Output voltage Proceed to step 4 emitter TP46 to collector decreases TP68 5 11 Table 5 5 Series Regulator Troubleshooting High Output Voltage Continued ACTION Check turn on of error amplifier 042 by momentarily shorting base TP44 to collector TP68 Check turn off of mixer amplifier 041 by momentarily shorting TP40 to emitter TP47 Output voltage remains high Output voltage decreases Output voltage remains high Output voltage decreases Measure the voltage at pin 1 of constant voltage comparator Z1 between TP11 and the
91. g due to the positive bias supplied to its base through 84 Transistor 073 is cut off because its base is driven negative by the collector of Q72 4 25 When the negative threshold voltage is reached transistor O72 is turned off and Q73 is turned The conduction of Q73 allows capacitor C71 to discharge rapidly through pulse transformer 70 generating firing pulse across the secondary of T70 Diode CR88 blocks any posi tive overshoot 4 26 The control circuit is reset once every 8 33 milli seconds when the rectified ac voltage at the junction of CR77 CR78 and 79 TP82 forward biases diode CR78 Summing capacitor C70 is then allowed to discharge through CR78 Diodes CR74 and CR75 become reverse biased at reset allowing Q72 to turn on Consequentiy Q73 is turned off and capacitor C71 charges up through R79 at a compara tively slow rate until the collector voltage of Q73 reaches approximately 11 volts 4 27 Overvoltage Limit Circuit 4 28 Under norma circumstances Q70 in the overvoltage limit circuit is biased off by the equal voltages on its base and emitter Diodes CR70 and CR71 are forward biased by a small current through R71 to develop Q70 s base voltage R72 connected between Q70 s base and the supply s negative output shunts an amount of current away from the diodes that is proportional to the supply s output voltage When the output voltage reaches approxi mately 12096 of its rated maximum the diode curr
92. g resistor Ry produces aconstant voltage across the resistor Initially the battery voltage is high and the supply s output voltage is low but as the battery voltage decreases during discharge the supply voltage increases When the battery voltage reaches zero CURRENT POWER SUPPLY WITH CHARGING NORMAL STRAPPIN PATTERN OF FIG 3 2 E CONNECTED TAPER ARGING PATERE BATTERY FULL CHARGE VOLTAGE lc CONSTANT CHARGE CURRENT BATTERY VOLTAGE AT WHICH CHARGE RATE WILL BEGIN TO TAPER WITH INSERTION OF Figure 3 16 Battery Charging 3 13 the supply senses this through the connection to its A2 terminal and reduces the output current to zero If this automatic shutoff feature is not required the 10k ohm resistor may be omitted As shown in Figure 3 17 must be selected so that its IR drop is less than the maximum rated output voltage of the supply but greater than the initial battery voitage 3 94 To give a battery a constant current discharge proceed as follows a Turn off the power supply and disconnect the jumpers from terminal A1 to A2 and from A2 to A3 This step disables the supply s VOLTAGE controls b Connect terminal A3 to S and leaves all other jumpers connected as for normai operation as shown in Figure 3 17 c Connect the positive terminal of the battery to A2 through 10 resistor d Connect the positive terminal of the
93. ge when programmed to that level 4 39 Main output capacitor A3C3 connected across the output terminals of the supply stabilizes the series regulator feedback loop and helps supply high current pulses of short duration during constant voltage operation An additional output capacitor C19 is connected directly across the output bus bars to maintain a low ac output impedance by compensating for the inductive reactance of the main output capacitor at high frequencies C19 also helps to minimize output spikes 4 40 Constant Current Comparator 441 The constant current comparator is similar in appearance and operation to the constant voltage compara tor It consists of programming resistors A5R123 and A5R124 differential amplifier Z1 and associated components 4 42 The constant current comparator circuit compares the voltage drop across the CURRENT controls with the voltage drop across current sampling resistor A4R123 difference exists the differential amplifier produces an error signal proportional to this difference The remaining components in the feedback loop amplifiers and the series regulator maintain the drop across the current sampling resistor and hence the output current at a constant value 4 43 One input of the differential amplifier pin 7 is connected to the output bus through impedance equalizing resistor R20 and is zero biased by R21 and optional resistor R117 Its other input pin 4 is connected to the summ
94. h can also be remotely programmed Refer to the appropriate sections of paragraph 3 34 for the additional rear panel connections required and make these connections to the master supply only Observe all precautions outlined in the paragraphs on EXT CROWBAR TRIGGER fx 2 4 5 S S MASTER Figure 3 12 Auto Series Operation of Two Units 3 10 remote programming The simultaneous use of remote sensing and remote programming is also possible during auto series operation 3 67 Auto Tracking Operation 3 68 Figures 3 14 and 3 15 show the rear panel inter connections required to operate two or three supplies in the auto tracking mode This mode of operation allows two or three supplies that share a common negative output bus to power separate loads and have their outputs simultaneous 1 programmed by the voltage and current controls of a master supply Unless their outputs are to be equal the supply that is to have the greatest output voltage must be selected as the master The output voltage of each slave supply remains a constant percentage of the master s with the percentage for each slave established by that slave s voltage contro settings and the choice of its externa programming resistor Ry Any of the supplies included in this manual can be used as an auto tracking slave and any well regulated variable output supply can
95. he output of the supply would have the following disadvantages a With additional capacitance connected the output impedance of the supply decreases with increasing frequency b With additional capacitance connected the output current takes longer to recover from the effects of a change in the load resistance c With additional capacitance connected a rapid reduction in load resistance can produce a larger than normal surge current that could cause a high power dissipation in the load 3 82 Reverse Voltage Protection 3 83 One or two internal diodes 4 106 or 4 106 and A4CR107 connected with reverse polarity across the output terminals of the supply protect the output electrolytic capacitors and series transistors from the effects of a reverse voltage applied across the supply s output Such a reverse voltage might inadvertently be applied when operating supplies in series if one of them were to be turned on or off before the other The current rating of the output diodes is equal to the rated output current of the supply 3 84 The series regulator transistors are also protected against reverse voltage by diode A4CR105 This diode shunts the series regulators if the supply is connected in parallel with another supply but is deenergized 3 85 Reverse Current Loading 3 86 An active load connected to the power supply may actually deliver a reverse current to the supply during a portion of its operating cycle If an ex
96. heckout procedure or the more detailed performance side of the ac line Do not fail to connect the test of paragraph 5 5 should be followed when the instru input ground terminal securely to an ment is received and before it is connected to any load external earth ground equipment Proceed to the more detailed test and trouble shooting procedures in Section V if any difficulties are Set LINE switch or circuit breaker ON and encountered observe that pilot lamp lights a Turn CURRENT controls and OVERVOLTAGE d Adjust COARSE and FINE VOLTAGE controls ADJUST potentiometer fully clockwise and check for desired indication on voltmeter that rear panel straps are connected as shown in Figure 3 2 Ensure that overvoltage crowbar circuit is operational but do not connect load RI by slowly turning OVERVOLTAGE ADJUST control b Connect ac power of the appropriate voltage and counterclockwise with a screwdriver OVERVOLTAGE frequency to the rear panel ac and acc terminals The lamp 8 lights and voltmeter indication drops to zero supply s input rating is identified on its rear panel volts 3 1 f Reset crowbar by returning OVERVOLTAGE ADJUST control to its maximum clockwise position and turning off the supply On turning the supply back on the voltage should be the same value as was set in step d g To check the constant current circuit first turn off the supply connect a short across the output bus bars see Figur
97. his is particularly important when measuring the regula tion transient response or ripple of the power supply Note that the measuring instruments should not be connected across the load 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 typically less than 1 milliohm at dc thus invalidating the measurement 5 9 To avoid mutual coupling effects connect each monitoring device to the sensing terminals by a separate pair of leads Use twisted pairs or shielded two wire cables to avoid pickup on the measuring leads Connect the load resistor across the output terminals as close to the supply as possible When measuring the constant voltage perfor mance specifications set the current controls well above at least 1096 above the maximum output current the supply wil draw since the onset of constant current operation will cause a drop in output voltage increased ripple and other performance changes not properly ascribed to the constant voltage operation of the supply 5 10 Voltage Output and Voltmeter Accuracy To check that the supply will furnish its rated output voltage proceed as follows a Connect load resistor Ry indicated in Figure 5 1 across output terminals of supply b Connect digital voltmeter across S and S terminals of supply observing correct polarity Turn CURREN
98. hould be notified as soon as possible 2 3 Mechanical Check 2 4 This check should confirm that there are broken knobs or connectors that the cabinet and panel surfaces are free of dents and scratches and that the meters are not scratched or cracked 2 5 Electrical Check 2 6 The instrument should be checked against its electrical specifications Section V includes an in cabinet performance check to verify proper instrument operation 2 7 INSTALLATION DATA 2 8 The instrument is shipped ready for permanent rack installation or bench operation It is necessary only to connect the instrument to a source of power and it is ready for use 2 9 Location and Cooling 2 10 These instruments are fan cooled and must be installed with sufficient space for cooling air to reach their sides These power supplies should be used in an area where the ambient temperature does not exceed 55 C 2 11 Outline Diagram 2 12 Figure 2 1 shows the outline shape and dimensions of these supplies 2 13 Rack Mounting 2 14 This instrument is ful rack size and can be easily rack mounted in a conventional 19 inch rack panel using standard mounting screws 2 3 TERMINAL STRIP DETAIL E TERM LY s Figure 2 1 Outline Diagrams Models 6259B 6260B 6261B 6268B and 6269B 2 15 INPUT POWER REQUIREMENTS 2 16 The standard instrument is wired for a nominal input of 230Vac 57 63Hz wh
99. icated on digital voitmeter e Short circuit load resistor RI f Digital voltmeter reading should not differ from reading recorded in step d by more than 6259B 110uV 6260B 110uV 6261B 110uV 62688 134uV 62698 120uV 5 44 Source Effect Line Regulation Definition The change Aout in the static value of dc output current resulting from a change in ac input voltage over the specified range from low fine to high line or from high line to low tine 5 45 Tocheck source effect proceed as follows a Connect test setup shown in Figure 5 7 b Connect variable autotransformer between input power source and power supply ac input c Adjust autotransformer for 208Vac input d Turn VOLTAGE controls fully clockwise e Turn on supply and adjust CURRENT controls until front panel ammeter reads exactly maximum rated output current f Read and record voltage indicated on digital voltmeter g Adjust autotransformer for 254Vac input h Digital voltmeter reading should not differ from reading recorded in step f by more than 62598 110uV 6260B 110 62618 110uV 6268B 134uV 6269B 120uV 546 PARD Ripple and Noise Definition The residua ac current superimposed on the dc output of a regulated power supply Rippte and noise measurements may be made at any input ac line voltage combined with any dc output voltage and load current within the supply s rating 547 Most of the instructions pertaining to the ground loop and
100. inductor fxd met ox 1 5k 5 2W omit for 230Vac or 208Vac operation fxd met ox 220 5 2W varistor 250Vac A3 Interconnection Board Electrical See Note 1 fxd elect 8600uF 25V fxd elect 50004F 45V connector PC board edge fxd comp 51k 5 1 2W bias transformer A4 Heatsink Ass y Electrical See Note 1 fan cooling 115Vac 50 60Hz fxd cer O5uF 400V fxd elect 15uF 50V diode Si 40A 100V diode Si 100 100V diode Si 85A 100V diode Si 40A 100V diode Si 85A 100V diode Si 40A 100V diode Si 40A 100V diode Si 40A 100V diode Si 40A 100V thyristor Si SCR power PNP Si power NPN Si power NPN Si power NPN Si power NPN Si nearest commercial equivalent 6 9 MFG PART NUMBER FP 42 V250LA40B 32D D46882 DOB 360 038008 64 718 22 5135 WS2107FL 55 33C17A3 CDH 150D156X0050R2 1N1184AR 1N3289R R3710 1N1184A 3710 1 1184 1N1184A 1N1184A 1N1184AR 2N3898 2N4902 2N3772 60675 2N3771 60675 MFG CODE HP PART NUMBER 5080 1781 5080 1782 0698 3338 0698 3628 0837 0117 0180 1882 0180 1919 1251 1887 0686 5135 9100 2607 3160 0056 0150 0052 0180 1834 1901 0318 1901 0536 1901 0729 1901 0317 1901 0730 1901 0318 1901 0317 1901 0317 1901 0318 1884 0058 1853 0063 1854 0225 1854 0458 1854 0245 1854 e Table 6 4 Replaceable Parts MFG CODE HP PART N
101. ing point terminal A6 at the junction of programming resistors A5R123 and A5R124 and current pullout resistors R30 and R31 Instantaneous changes in the output current due to load changes or changes in the voltage at the summing point due to changes in the CURRENT control setting produce a difference voltage between the two inputs of the differential amplifier This difference voltage is amplified and appears at the output of the differential amplifier pin 6 as an error voltage which ultimately varies the conduction of the series regulator 4 44 Resistor R30 serves as a trimming adjustment for the programming current flowing through 123 and A5R124 If the supply is equipped with Option 021 or 040 resistor R115 and potentiometer R116 allow the programming current to be adjusted over a narrow range around its nominal value and resistor R118 and potentiometer R119 provide a variable input bias to allow the output current to be easily adjusted to exactly zero when the supply is programmed for zero output Diode CR21 limits excessive voltage excursions at the summing point input to the differential amplifier 4 45 Voltage Clamp Circuit 4 46 The voltage clamp circuit keeps the constant voltage programming current relatively constant when the power supply is operating in the constant current mode This is accomplished by clamping terminal A2 the voltage summing point to a fixed bias voltage During constant current operation the co
102. ing a Standard Instrument to 115 Volt Operation Mode 6260 k A S RN 2 3 2 28 Converting a Standard Instrument to Operation 2 3 2 30 INPUT POWER CONNECTIONS 2 3 2 32 REPACKAGING FOR SHIPMENT 24 OPERATING INSTRUCTIONS 3 1 TURN ON CHECKOUT PROCEDURE OPERATING MODES NORMAL OPERATING MODE Constant Voltage Operation Constant Current Operation Overvoltage Trip Point Adjustment 3 2 3 1 33 3 6 3 8 3 10 3 12 Hi Section III con t IV 3 15 3 20 3 22 Connecting The Load Operation With No Load Operation Beyond Rated Output OPTIONAL OPERATING 3 24 3 27 3 34 3 51 3 57 3 67 3 76 Remote Voltage Sensing Remote Programming Auto Parallel Operation Auto Series Operation Auto Tracking Operation SPECIAL OPERATING CONSIDERATIONS Pulse Output Capacitance Reverse Voitage Protection Reverse Current Loading Battery Charging Battery Discharging 3 77 3 79 3 82 3 85 3 87 3 91 PRINCIPLES OF OPERATION 4 1 OVERALL BLOCK DIAGRAM DISCUSSION DETAILED CIRCUIT ANALYSIS Preregulator Control Circuit Overvoltage Limit Circuit Series Regulator and Driver Short Circuit Protection Constant Voltage Comparator Constant Current Comparator Voltage Clamp Circuit Mixer and Error Amplifiers Overvoltage Protection Crowbar Tu
103. ion CRT cathode ray tube center tapped dc direct current DPDT double pole double throw DPST double pole single throw elect electrolytic encap encapsulated F 7 farad OF degree Farenheit fixed germanium Henry Hertz integrated circuit inside diameter incandescent kilo 103 milii 1073 mega 106 micro 10 met metal mfr manufacturer modular or modified mounting nano 10 normally closed normally open nickel plated ohm order by description outside diameter pico 10 12 printed circuit potentiometer peak to peak parts per million peak reverse voltage rectifier root mean square silicon SPDT single pole double throw SPST single pole single throw SS small signal slow blow tantulum titanium volt variable wirewound Watt Table 6 3 Code List of Manufacturers CODE MANUFACTURER ADDRESS EBY Sales Co Inc Aerovox Corp Sangamo Electric Co S Carolina Div Allen Bradley Co Milwaukee Wis Litton Ind Beverly Hills Calif TRW Semiconductors Inc Lawndale Calif Dallas Texas Manchester N H Rockford Dover Ohio Saugerties Jamaica N Y New Bedford Mass Pickens S C Texas Instruments Inc RCL Electronics Inc Amerock Corp Sparta Mfg Co Ferroxcube Corp Fenwal Laboratories Morton Grove 111 Amphenol Corp Broadview Ill Radio Corp of America Solid State and Receiving Tube Div Somer
104. iques Figure 5 2A shows an incorrect method of measuring peak to peak ripple Note that a continuous ground loop exists from the third wire of the input power cord of the supply to the third wire of the input power cord of the oscilloscope via the grounded power supply case the internal jumper connecting the power supply negative output and sensing terminats the wire between the negative sensing terminal of the power supply and the vertical input of the scope and the grounded scope case Any ground current circulating in this loop as a result of the difference in potential between the two ground points causes IR drop which is in series with the scope input This IR drop normally having a 60Hz line frequency fundamental 53 plus any pickup on the unshielded leads interconnecting the power supply and scope appears on the face of the CRT The magnitude of this resulting noise signal can easily be much greater than the true ripple developed between the plus and minus sensing terminals of the power supply and can comptetely invalidate the measurement 5 18 The same ground current and pickup problems can exist if an rms voltmeter is substituted for the oscillo scope in Figure 5 2A However the oscilloscope display unlike the true rms meter reading tells the observer immediately whether the fundamental period of the signal displayed is 8 3 milliseconds 1 120Hz or 16 7 milliseconds 1 60Hz Since the fundamental ripple frequenc
105. ired ful charge voltage The added 0 7 volts compensates for the drop across CRp The supply may then be connected to the battery terminals Positive to positive and negative to negative as shown in Figure 3 16 omit Ry 3 90 Taper Charge When charging lead acid ceils many manufacturers recommend that the charging current be reduced as the charge nears completion This can be accomplished by inserting a small resistance in series with one of the load leads from the supply to the battery See Figure 3 16 This resistor alters the normally rectan gular charging plot in such a manner as to provide a taper charge for the last portion of the charge The proper value for this resistor is the difference between the full charge voltage and the voltage at which the tapering is to start divided by the initial charging current Set the initial charging rate and full charge voltage as instructed in paragraph 3 89 3 91 Battery Discharging 3 92 These power supplies are also useful when batteries must be discharged at a constant current in order to test them Connecting a supply as shown in Figure 3 17 and following the instructions below makes an unattended constant current discharge possible by automatically shutting off the output of the supply when the battery voltage reaches zero 3 93 The supply operates in the constant current mode delivering the current set by the current control This con stant current flowing through droppin
106. lue of load resis tance the power supply must act either as a constant voltage source or as a constant current source To enable one comparator or the other to take control the outputs of both comparators are connected to the input of the mixer amplifier through an OR gate 4 9 Figure 4 2 shows the output characteristic of a constant voltage constant current power supply With no load connected the output current lour is zero and the output voltage EouT equals the front pane voltage con trol setting Ec When a load resistance is connected to the output terminals of the supply the output current increases while the output voltage remains constant Point D thus represents a typica constant voltage operating point Further decreases in load resistance are accompanied by further increases in lout with no change in the output voltage until the output current reaches 15 value equal to the front panel current control setting At this point the supply automatically changes its mode of operation and becomes a constant current source Still further decreases in the value of load resistance are accompanied by a drop in the supply s output voltage with no accompanying change in its output current With a short circuit across the load terminals louT Eout 0 4 10 The crossover value of load resistance can be defined as Rc 5 15 Adjustment of the front panel voltage and current controls permit this crossover
107. measurement method A waveshape having 60Hz as its fundamental component usually indicates an incorrect measurement setup 5 48 To check the ripple and noise proceed as follows a Connect oscilloscope or rms voltmeter as shown in Figure 5 8A or 5 8B b Rotate VOLTAGE controls fully clockwise c Turn on supply and adjust CURRENT controls until front panel ammeter reads exactly maximum rated output current d The observed ripple and noise should be less than 6259B 250uV rms 6260B 250uV rms 62618 250uV rms 6268B 334uV rms 6269B 250uV rms 5 49 TROUBLESHOOTING 5 50 Before attempting to troubleshoot this instrument ensure that the fault is with the instrument and not with an associated circuit The performance test paragraphs 5 5 through 5 48 enables this to be determined without removing the instrument from the cabinet 5 51 A good understanding of the principles of opera tion is a helpful aid in troubleshooting and it is recom mended that the reader review Section IV of the manua before attempting to troubleshoot the unit in detail Once the principles of operation are understood refer to the overal troubleshooting procedures in paragraph 5 54 to locate the symptom and probable cause 5 52 The schematic diagram contains normal voltage readings adjacent to some test points Test points are identified by circled numbers The measurement conditions are listed in the Schematic Notes Consult the component location diag
108. mum Crowbar Trip Voltage Adjustment 5 107 To adjust the maximum voltage at which the crowbar fires proceed as follows Rotate A5R125 OVERVOLTAGE ADJUST and CURRENT controls fully clockwise b Disconnect one end of R72 at TP70 or TP71 to temporarily disable the overvoltage limit circuit c Connect decade resistance box in place of R95 mounted on standoffs on main circuit board d Turn on supply and adjust VOLTAGE controls for output voltage shown below Model Value 6259B 12Vdc 62608 12Vdc 6261B 23Vdc 62688 45Vdc 6269B 45Vdc e Adjust decade resistance box until crowbar fires f Replace decade resistance with appropriate value resistor in R95 position and reconnect resistor R72 Maxi mum crowbar trip voltage is now set at voltage given in step d 5 108 Disabling the Crowbar 5 109 disable the crowbar completely disconnect either end of R98 at TP96 or TP97 on the main circuit board 5 20 SECTION VI REPLACEABLE PARTS 6 1 INTRODUCTION 62 This section contains information for ordering re placement parts Table 6 4 lists parts in alpha numeric order by reference designators and provides the following informa tion a Reference Designators Refer to Table 6 1 b Description Refer to Table 6 2 for abbreviations c Manufacturer s Part Number or d Manufacturer s Federal Supply Code Number Refer to Table 6 3 for manufacturer s name and address e Hewlett Packard Part Number
109. n signal between its two vertical input terminals thus ignoring the effects of any common mode signal produced by the difference in the ac potential between the power supply case and scope case Before using a differential input scope however it is imperative that the common mode rejection capability of the scope be verified by shorting together its two input leads at the power supply and observing the trace on the CRT If this trace is a straight line then the scope is properly ignoring any common mode signal present If this trace is not a straight line then the scope is not rejecting the ground signal and must be realigned in accor dance with the manufacturer s instructions so that proper common mode rejection is attained 5 23 Ripple Measurement Procedure To check the ripple output proceed as follows 54 a Connect oscilloscope or rms voltmeter as shown in Figures 5 2A or 5 28 b Turn CURRENT controls fully clockwise c Turn on supply and adjust VOLTAGE controls unti front panel meter indicates maximum rated output voltage d The observed ripple should be less than 6259B 6260B 6261B 500uV rms 5mV 6268B 6269B 1mV rms bm V 5 24 Noise Spike Measurements An instrument of sufficient bandwidth must be used when making a high frequency spike measurement An oscilloscope with a bandwidth of 20MHz or more is adequate Measuring noise with an instrument that has insufficient bandwidth may conceal high frequ
110. n controlled rectifier A4CR110 has been triggered it acts as an open circuit and has no effect on the output voltage Transistors O91 and Q92 detect an overvoltage condition and trigger the SCR to fire When the SCR fires it shorts the supply s output 4 54 During normal operation O92 is biased on by current through R99 Q91 is kept turned off by Q92 and CR91 is reverse biased by the voltage divider formed by resistors R90 R95 and ASR125 Zener diode VR9O provides a stable reference voltage with which the 5 potential is compared Potentiometer ABR125 OVER VOLTAGE ADJUST establishes the output voltage at which CR91 becomes forward biased and turns Q92 off When 092 turns off O91 begins to conduct sending a positive going trigger pulse to 4 110 and causing it to create a near short circuit across the output When A4CR110 fires overvoltage lamp 5052 turns on completing a path for a 11V unregulated holding current through 5052 R92 supplies the holding current if the lamp should open This current holds A4CR110 on even after the output voltage has fallen A4CR110 remains in conduction until the supply is turned off AAR106 protects 4 108 and A4CR110 from the large surge current that occurs when A4CR110 is first fired CR93 damps out negative over shoot in the trigger pulse 4 55 The firing of A4CR110 biases Q90 into conduction This places approximately 11 volts on the cathode of CR74 in the preregulator contr
111. n the same instrument Rewiring for 115Vac 10 Single Phase Input Models 6259B 6261B and 6268B only This factory modification replaces the circuit breaker except in the Model 6259B adds resistor to the A2 assembly and reconnects the power transformer bias transformer preregulator choke and fans for 115Vac operation Rewiring for 208Vac 10 Single Phase Input This factory modification reconnects the power and bias transformers for 208Vac operation Interfacing for Multiprogrammer Operation This factory modification prepares standard power supplies for resistance programming by the 6940B Muitiprogrammer or the 6941B Multiprogrammer Extender Operation with either of these instruments requires that the power supply be subjected to a special calibration and a protection checkout The special calibration insures that the power supply can be accurately set to zero and to the maximum rated output voltage or current when programmed by the multiprogrammer The protection checkout insures that the power supply will not be damaged by the rapid repetitive programming possible with the multiprogrammer This option includes Option 022 A2 assembly and reconnects the bias trans 1312 INSTRUMENT MANUAL IDENTIFICATION former preregulator choke and fans for 115Vac operation 1 13 Hewlett Packard power supplies are identified by a two part serial number The first part is the serial number prefix a number le
112. nstant voltage programming resis tors are a shunt load across the output terminals of the supply When the output voltage changes the current through these resistors also tends to change Since this programming current flows through the current sampling resistor it is erroneously interpreted as a load change by the current comparator circuit The voltage clamp eliminates this undesirable effect by maintaining the programming current at a constant level 4 47 The voltage divider consisting of Z2A Z2B and back biases CR2 and O1 during constant voltage operation When the power supply goes into constant current operation CR2 becomes forward biased by the voltage at pin 12 of Z1 This results in the conduction of O1 and the clamping of the summing point at a potential only slightly more negative than the normal constant voltage potential Clamping this voltage at approximately the same potential that exists in constant voltage operation results in a constant voltage across and consequently constant current through current pullout resistors R3 R4 and R5 4 48 Mixer and Error Amplifiers 4 49 The mixer and error amplifiers amplify the error signal received from the constant voltage or constant current input circuit to a level sufficient to drive the series regulator transistors Mixer amplifier Q41 receives the error voltage input from either the constant voltage or constant current comparator via the OR gate diode CR1 or CR20
113. nt current comparator circuit Z1 and associated components Poor load regulation Constant voltage Poor load regulation ncorrect reference or bias voltages Refer to Table 5 2 Constant current b Supply voltage limiting Check constant voltage comparator circuit Z1 and associated components and voltage clamp circuit Q1 c Leaky C19 A3C3 d CR92 defective o Adjustment of R47 Refer to paragraph 5 98 b Faulty C40 C41 C19 A3C3 R50 Open sensing lead S Oscillates Constant current or constant voltage Incorrect reference or bias voltages CR92 defective Refer to Table 5 2 b Noisy voltage or current controls A5R121 5 122 or 5 123 A5R124 noisy VR60 or VR61 c Integrated circuit Z1 defective d CR4 CR5 CR6 or CR21 leaky R3 R4 R5 R6 R22 R30 R31 C2 noisy or drifting Instability Constant current constant voltage 020 shorted One or more series regulator transistors A4Q103 thru 40110 open Cannot reach maximum output Table 5 4 Feedback Loop Isolation Breaker tripped Check rectifier filter and triac for short Proceed to step 3 Breaker OK output Proceed to step 2 voltage high Breaker OK output Proceed to step 2 voltage low 5 10 Table 5 4 Feedback Loop Isolation Continued Inspect OVERVOLTAGE lamp Check setting of OVERVOLTAGE on front panel ADJUST 5 1
114. nts the nominal output voltage defined in the specification h Adjust the horizontal positioning control so that the trace starts at a major graticule division This point then represents time zero i Increase the sweep rate so that a single transient spike can be examined in detail j Adjust the sync controls separately for the positive and negative going transients so that not only the recovery waveshape but also as much as possible of the rise time of the transient is displayed k Starting from the major graticule division representing time zero count to the right 50 and vertically 10mV Recovery should be within these tolerances as illustrated in Figure 5 5 POWER SUPPLY UNDER TEST OSCILLOSCOPE CONTACT PROTECTION NETWORK c 2 545 108 58 NOTE 3 THIS DRAWING SHOWS SUGGESTED METHOD OF BUILDING LOAD SWITCH HOWEVER OTHER METHODS COULD BE USED SUCH AS A TRANSISTOR SWITCHING NETWORK MAXIMUM LOAD RATINGS OF LOAD SWITCH 5 AMPS 500 V 250W NOT 2500W USE MERCURY RELAY CLARE TYPE HPG 1002 OR WE TYPE 2768 REPETITIVE USE WIREWOUND RESISTOR OAD SWITCH NOTE l 5 RL 5 22 50 24 50w 4Q 100 80 200 8 200 Figure 5 4 Load Transient Recovery Time Test Setup UNLOADING TRANSIENT NOMINAL OUTPUT VOLTAGE LOADING TRANSIENT NOMINAL OUTPUT VCLTAGE 50 8 LOAD NS TRANSIENT
115. ol circuit to reverse bias CR74 and CR75 By preventing transistor Q72 from turning off this prevents the generation of any trigger pulses and turns off the preregulator 4 b6 The crowbar circuit creates an extra current path during normal operation of the supply thus changing the current that flows through the sampling resistor Diode CR92 keeps this extra current at a fixed level for which compensation can then be made in the constant current comparator circuit 4 57 A slaving arrangement for the crowbar circuits in more than one supply 15 made possible by an extra secondary winding terminals 5 and 6 T90 This wind ing is connected to terminals on the rear barrier strip marked EXT CROWBAR TRIGGER When two or three units have these windings connected in parallel all of their crow bars are activated when any one of the crowbars is tripped To reset the crowbars in this arrangement at of the units must be turned off and then on Polarity must be observed when connecting units in this fashion 4 58 Turn On Control Circuit 4 59 The turn on control circuit is a long time constant network which protects the triac and the series regulator from possible damage during turn on When the supply is first turned on C35 applies a positive voltage to the anodes of CR35 and CR36 Diode CR35 couples this voltage to the cathode of CR74 in the preregulator control circuit to ensure that it is initially reverse biased After C35 becomes
116. olts the solution for Rx is Ry 40V x 2 5kQ 10V Ry 5kQ 3 70 It is also possible to make an auto tracking slave s voltage equal the output of the master supply To do this make direct connection from the S terminal of the master to the A2 terminal of the slave instead of using a programming resistor and remove the slave s A1 to A2 jumper 3 71 Setting the Voltage and Current Controls The voltage control of each slave must be set fully clockwise to obtain the voltage ratios established by the formula for Rx given in paragraph 3 69 By lowering the settings of the slave s voltage controls the voltage of the slave can be made a smaller percentage of the master supply s voltage The current controls of all supplies in an auto tracking combination are independently operative and can be used to set current limits for each individual load 1f the master supply goes into constant current mode the output voltages of the slaves continue to track that of the master If a slave supply goes into constant current mode however no other supply is affected 3 72 Overvoltage Protection Auto Tracking Parallel ing the crowbar circuits as is required for the auto parallel and auto series modes is optional in the auto tracking mode If the external trigger windings of transformer T90 in the master and in the stave supplies are not paralleled the overvoltage protection circuit in each supply indepen dently monitors th
117. ompietely remove interconnection circuit board remove two screws holding board to support tray one screw holding A3C3 capacitor clamp to support tray and two screws holding bias transformer A3T2 to support tray Unsolder connections to board marking wires to enable correct replacement and remove board 5 69 REPAIR AND REPLACEMENT 5 70 Section VI of this manual contains a list of replaceable parts If the part to be replaced does not have a standard manufacturers part number it is a special part and must be obtained directly from Hewlett Packard After replacing a semiconductor device refer to Table 5 8 for checks and adjustments that may be necessary All components listed in Table 5 8 without A designators are on the A1 main printed circuit board 5 71 ADJUSTMENT AND CALIBRATION 5 72 Adjustment and calibration may be required after performance testing troubleshooting or repair and replace ment Perform only those adjustments that affect the operation of the faulty circuit 5 73 Meter Zero Adjustment 5 74 The meter pointer must rest on the zero calibration mark on the meter scale when the instrument is at normal operating temperature resting in its normal operating position and turned off To zero the meter proceed as follows Connect load resistor of value shown in Figure 5 1 turn on instrument and allow it to come up to normal operating temperature about 30 minutes b Turn instrument off and wait two minutes fo
118. ons require the use of output distribution terminals that are located remotely from the supply then the power supply output terminals should be connected to the remote distribution terminals by a pair of twisted or shielded wires and each load should be separately connected to the remote distribution terminals Remote voltage sensing would be required under these circumstances Refer to paragraph 3 27 3 19 Either positive or negative voltages can be obtained trom this supply by grounding one of the output terminals or one end of the load Always use two wires to connect the load to the supply regardless of where or how the system is grounded Never ground the system at more than one point This supply can be operated up to 300 volts above ground if neither output terminal is grounded 3 20 Operation With No Load 3 21 When the supply is operated without a load its down programming speed is considerably slower than when its output is loaded This slower programming speed is evident whether the VOLTAGE controls are turned fully counterclockwise or an external voltage programming input signal is decreased When the crowbar is activated during no load operation the supply s output falls rapidly to about two volts and then decreases more slowly towards zero The actual time required for the output to fall from two volts to zero varies from several seconds to several minutes depending on the output rating of the supply 3 22 Operation Beyon
119. ould tend to rise Although the increase would be limited by protective resistors R108 and R109 damage to the supply or to the load might occur if the loss of sensing were accompanied by a load transient For this reason no switch relay or connector contacts should be included in the remote sensing path CAUTION When using remote voltage sensing it is possible to damage the supply by d sconnecting a load lead while the sensing lead is still connected and the supply is energized If a load lead becomes disconnected current flows through internal protection resistors R108 and R109 the sensing leads and the load and may burn out the resistors Additional factors could compound the damage caused by an opened load lead If the output of the supply is connected to an inductive load or a battery or is connected in parallel with another supply then opening a load lead would allow current from the external source to flow through the sensing leads and damage the supply 5 input circuits If the crowbar fires the damage could even be greater For these reasons if there is any risk of an opened load circuit while remote sensing is used 1 16 amp fuses should be installed in both sensing leads Fuses in the sensing leads will not affect the performance of the supply and should protect against costly damage Remote sensing is not recommended when charging or discharging a battery See paragraphs 3 87 and 3 91 3 33 Another facto
120. pen A4R150 through A4R165 as applicable open A4CR106 or AACR107 shorted Proceed to step 2 O42 shorted CR44 shorted Proceed to step 3 71 defective open strap between and A7 or shorted A5R123 or 124 Reconnect CR20 and proceed to step 4 041 or open O40 shorted Proceed to step 5 Open strap between A2 and CR7 or Q1 shorted VR1 R3 R4 or R5 open CR4 71 or 22 defective Table 5 7 Preregulator Troubleshooting See Figure 4 4 for Waveforms Connect oscilloscope between Normal waveform a Proceed to step 2 TP85 and TP103 Little or no voltage Defective O72 O73 CR76 or C71 Proceed to step 3 Connect oscilloscope between Normal waveform Defective A2CR1 A2L1 1 2 1 A2C3 TP89 and TP86 Little or no voltage Defective T70 CR88 R88 Proceed to step 3 To avoid a potentially lethal shock hazard a differential oscilloscope must be used in making this measurement Connect oscilloscope between a Amplitude incorrect a Defective O71 C70 C72 CR74 CR75 TP80 and TP103 R75 R78 or R82 b Period incorrect b CR78 defective Proceed to step 4 Connect oscilloscope between Amplitude dc reference Defective CR77 CR78 CR79 CR80 82 and TP103 or period incorrect CR82 CR84 Check R87 Connect oscilloscope between Amplitude dc reference Defective CR81 CR83 R83
121. possible during auto parallel operation 3 57 Auto Series Operation EXT CROWBAR TRIGGER MASTER Figure 3 10 Auto Parallei Operation of Two Units 3 8 3 58 Figures 3 12 and 3 13 show the rear panel and circuit board interconnections required to operate two or three supplies in the auto series mode This mode of operation allows two or three series connected supplies to be simultaneously programmed by the voltage and current controls of a master supply The master supply must always be the one at the positive end of the series combination The output voltage of each slave supply varies in direct proportion to that of the master and the ratio of each slave s output voltage to the master s is established by the settings of the slave supplies voltage controls The resulting combination of two or three supplies behaves as if it were a single constant voltage constant current supply The supply with the lowest current rating limits the maximum output current of the combination Any of the supplies included in this manual can be used as an auto series slave and any well regulated variable output supply can be used as the master 3 59 In applications where coordinated positive and negative voltages are required grounding the center tap of an auto series combination of supplies allows simultaneous proportional control of both supply voltages 3 60 Determining the Value for Each slave supply h
122. ption 021 or Option 040 Instrument To calibrate the constant current programming current of an Option 021 or Option 040 instrument proceed as follows Perform steps a through c of paragraph 5 96 b Rotate VOLTAGE controls fully clockwise and turn on supply c Adjust potentiometer R116 labeled CURRENT PROG and accessible through hole in rear panel until digital voltmeter indicates 0 5 Vdc 10mV 5 98 Load Transient Recovery Time Adjustment 5 99 follows Connect test setup shown in Figure 5 4 b Repeat steps a through k as outlined in paragraph 5 30 c Adjust R47 until transient response to within specification as shown in Figure 5 5 To adjust the transient response proceed as 5 100 Ripple Balance Adjustment 5 101 This procedure ensures balanced triac operation by ensuring that its conduction time is within 2596 of being equal in both directions To check for imbalance proceed as follows Connect load resistor specified in Figure 5 1 across rear output terminals of supply b Connect variable autotransformer between input power source and power supply input and adjust it for a 230Vac input to the supply c Connect ac coupled oscilloscope across series regulator between TP102 and TP103 d CURRENT controls fully clockwise turn supply and adjust VOLTAGE controls for maximum rated output voltage e Adjust oscilloscope to observe 120Hz sawtooth waveform Peak amplitudes of
123. r power supply capacitors to discharge completely c Insert pointed object pen point or awl into small indentation near top of round black plastic disc located directly below meter face d Rotate plastic disc clockwise until meter reads zero then rotate counterclockwise slightly in order to free adjustment screw from meter suspension Pointer should not move during latter part of adjustment 5 75 Voltmeter Calibration 5 76 To calibrate the voltmeter proceed as follows a Connect dgita voltmeter across plus and minus output terminals of supply observing correct polarity b Turn on supply and adjust VOLTAGE controls until digital voltmeter reads exactly the maximum rated output voltage c Adjust R106 until front panel voltmeter also indicates exactly the maximum rated output voltage 5 77 Ammeter Calibration 5 78 To calibrate the ammeter proceed as follows a Connect test setup shown in Figure 5 7 b Turn VOLTAGE controls fully clockwise Turn on supply and adjust CURRENT controls until digital voltmeter reads 500mV d Adjust R101 until front panel ammeter indicates exactly maximum rated output current 5 79 Constant Voltage Programming Calibration 5 80 To calibrate the zero voltage programming accuracy proceed as directed in paragraph 5 81 5 82 5 83 5 84 or 5 85 whichever applies to your particular instrument To calibrate the constant voltage programming accuracy proceed as directed in paragraph 5
124. r supply to the vertical input terminals of the scope When using a twisted pair take care that the same wire is connected both to the grounded terminal of the power supply and the grounded input terminal of the oscilloscope When using shielded two wire cable it is essential for the shield to be connected to ground at only one end to prevent any ground current flowing through this shield from inducing a signal in the shielded leads 5 21 To verify that the oscilloscope is not displaying ripple that is induced in the leads or picked up from the grounds short the scope lead to the scope lead at the power supply terminals The ripple value obtained when the leads are shorted should be subtracted from the indicated ripple measurement 5 22 If the foregoing measures are used the single ended scope of Figure 5 2A might be adequate to eliminate extraneous ripple components so that a satisfactory measurement can be obtained However in stubborn cases or in measurement situations where it is essential that both the power supply case and the oscilloscope case be connected to ground if both are rack mounted for example it may be necessary to use a differential scope with floating input as shown in Figure 5 2B If desired two single conductor shielded cables may be substituted in place of the shielded two wire cable with equal success Because of its common mode rejection a differential oscilloscope displays only the difference i
125. r to be considered when making a remote sensing installation is the inductance of the long load leads Although dc and low frequency performance are improved by remote sensing the higher inductance of longer leads does impair transient response and could affect the stability of the feedback loop seriously enough to cause oscillation remote sensing disturbs the supply s stability try these two corrective measures a Adjust the equalization control R47 until the oscilla tion stops To achieve the best possible transient response for a given remote sensing installation measure the transient response using the procedure given in paragraph 5 27 and adjust R47 while observing the transient response wave forms b If adjusting 47 does not eliminate the instability it may be beneficial to disconnect output capacitor A3C3 from the circuit and connect a similar capacitor directly across the load To gain access to capacitor A3C3 the A2 Assembly must first be removed Follow steps a through c of paragraph 5 65 to remove the A2 assembly Then unsolder the heavy wire from the A3 circuit board that connects the positive terminal of to the positive output bus bar This heavy red insulated wire is identified in Figure 7 2 NOTE Do not unsolder the capacitor s negative lead The negative lead to A3C3 carries collector current for transistor A40101 and would disable the power supply if disconnected Tape the free end of
126. rams in Section VII to determine the locations of components and test points 5 53 If a component is found to be defective replace it and re conduct the performance test When a component is replaced refer to the repair and replacement paragraph 5 69 and adjustment and calibration paragraph 5 71 sections of this manual 5 54 OVERALL TROUBLESHOOTING PROCEDURES 5 55 To the cause of trouble follow steps 1 2 and 3 in sequence 1 Check for obvious troubles such as a defective power cord an input power failure or a defective meter Next remove the top and bottom covers and inspect for open connections charred components or any other visible defects If the trouble source cannot be detected by visual inspection proceed to step 2 2 almost all cases the trouble can be caused by incorrect dc bias or reference voltages thus it is a good practice to check the voltages in Table 5 2 before proceed ing with step 3 3 Disconnect the load and examine Table 5 3 for your symptom and its probable cause 5 56 Table 5 3 contains symptoms and probable causes of many possible troubles If either high or low output voltage is a symptom Table 5 4 contains the steps necessary to isolate the trouble to one of the feedback loops and instructions directing the tester to the proper table for further isolation Because of the interactions between loops it is necessary to refer to Table 5 4 before proceeding to Tabl
127. re noise spikes Vary ac input for line regulation measurement Measure ac and dc voltages resistance Measure transient recovery time Power supply load resistor Measure output current calibrate ammeter Noise spike measurement Noise spike measurement RECOMMENDED MODEL HP 3450B HP 180C with 1821A time base and 1806A vertical plug in 1803A plug in for spike measurement HP 3490A 427A See Figure 5 4 53 TEST EQUIPMENT REQUIRED 5 4 Table 5 1 lists the test equipment required to perform the procedures described in this section 5 5 PERFORMANCE TEST 5 6 The following test can be used as an incoming inspection check 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 performed using a 230Vac 60Hz single phase input power source If the correct result is not obtained for a particular check do not adjust any internal controls instead proceed to troubleshooting paragraph 5 49 5 7 CONSTANT VOLTAGE TESTS 58 Connect all of the measuring devices used in the constant voltage performance tests directly to the power supply sensing terminals S For best accuracy the sensing terminals must be used rather than the output terminals since the measuring instruments must be connected to the same pair of terminals to which the feedback amplifier within the power supply is connected T
128. rent comparator The relationship between and the supply s output current depends on the resistance ratio Rp Rg and on the constant current programming coefficient Kp of the supply These coefficients are given in paragraph 3 47 The relationship between input voltage and output current is lout Eg x Rp Kp x Rp 3 49 When using this programming technique select a value for Rp that is less than 10k ohms and that would conduct at least 2 5 milliamps if connected across the programming voltage source with its voltage at the maximum value of input voltage to be used Once the value for Rn is selected multiply it by Kp x lout max Eg max to find Rp If desired the power supply s front panel current controls can be used in place of external gain control Rp by deleting the external gain control from the circuit and strapping together terminals A5 and A6 EXT CROWBAR TRIGGER AL eje 2 4 5 A7 8 S VOLTAGE SOURCE 3 INCLUDING INTERNAL IMPEDANCE OF VOLTAGE SOURCE Figure 3 8 Voltage Programming of Output Current Fixed Gain 3 50 The output current of the supply can be adjusted to exactly zero with a zero programming voltage input either by installing and adjusting R115 as discussed in paragraph 5 92 or if the instrument is equipped with Option 021 or 022 by adjusting potentiometer R116 as discussed in paragraph 5 94 3 51 Auto Parallel Opera
129. ring constant voltage operation the constant voitage comparator compares the output voltage of the supply with the drop across the VOLTAGE controls these voltages are not equal the comparator produces an error signal that is amplified and fed back to the series regulator with the correct phase and amplitude to make them equal In this manner the constant voltage comparator holds the output voltage at the level established by the VOLTAGE controls 4 7 During constant current operation the constant current comparator detects any difference between the voltage drop developed by load current flowing through the current sampling resistor and the voltage across the CURRENT controls If the two inputs to the comparator are momentarily unequal an error signal is generated that alters the conduction of the series regulator by the amount necessary to reduce the error voltage at the comparator s input to zero Hence the IR drop across the current sampling resistor and therefore the output current is held at a constant value 4 8 Since the constant voltage comparator causes the output impedance to be low and allows the output current to change whenever the load resistance changes while the constant current comparator causes the output impedance to be high and allows the output voltage to change in response to a load resistance change it is obvious that the two comparison amplifiers cannot contro the output simultaneously For any given va
130. rn On Control Circuit Reference Regulator Meter Circuit Additional Protection Features 4 16 4 17 4 27 4 29 4 31 4 33 4 40 4 45 4 48 4 52 4 58 4 61 4 66 4 70 MAINTENANCE 5 1 INTRODUCTION 5 3 TEST EQUIPMENT REQUIRED PERFORMANCE TEST CONSTANT VOLTAGE TESTS CONSTANT CURRENT TESTS TROUBLESHOOTING 5 5 PERFORMANCE TEST 57 5 38 5 49 Page 3 3 3 3 3 3 3 3 3 3 3 5 3 8 3 8 3 10 3 12 3 12 3 12 3 12 3 12 3 12 3 13 4 1 4 1 4 3 4 3 44 4 4 4 4 4 4 4 5 4 6 4 6 4 6 4 7 4 7 4 7 4 7 5 1 5 1 5 2 5 2 5 2 5 6 Section V con t 5 54 5 60 5 69 5 71 5 73 5 75 5 77 5 79 5 89 5 98 TABLE CONTENTS Continued Page OVERALL TROUBLE SHOOTING PROCEDURES 58 Disassembly Procedures 5 15 REPAIR AND REPLACEMENT 5 16 ADJUSTMENT AND CALIBRATION 5 16 Meter Zero Adjustment 5 16 Voltmeter Calibration 5 16 Ammeter Calibration 5 17 Constant Voltage Programming Calibration inne 5 317 Constant Current Programming Calibration 5 18 Load Transient Recovery Time Adjustment 5 19 Section con t VI VI 5 100 5 102 5 104 5 106 5 108 Ripple Balance Adjustment Preregulator Tracking Adjustment Crowbar Trip Voltage Adjustment Maximum Crowbar Trip Voltage Adjustment
131. ront panel meters 14 Output loads are further protected by a built in fast acting overvoltage protection crowbar circuit that automatically shorts the supply s output terminals if a preset voltage limit is exceeded A front panel contro sets the voltage at which the crowbar trips and can be adjusted from approximately 10 to 110 of the supply s maximum rated voltage When several supplies are installed in the same system whether in series parallel or independently their crowbar circuits can be interconnected so that all will trip simultaneously whenever any one of them does 1 5 These power supplies are forced air cooled 1 6 at rear panel terminals All dc output remote sensing and remote programming connections are also made at rear panel terminals Either the positive or negative output terminal of a supply may be grounded or the supply s output may be floated at up to 300 volts above ground 1 7 Remote programming remote sensing and several The ac input connections to these supplies are made 14 methods of operating supplies in combination of two or three are made possible by rear panel terminals that allow access to control points within the regulator circuits These capabilities are described below a Remote Programming The power supply s output voltage or current or both can be controlled from a remote location by varying a resistance or a voltage input signal to the supply s voltage or current regulator circuit
132. rrent in either direction Hence it fires whenever it receives a gating pulse regardless of the polarity of the ac voltage applied to it The triac is fired once during each half cycle of the ac input see Figure 4 3 When the triac is fired early in the half cycle the ac level applied to the power transformer is relatively high When the triac is fired later in the half cycle the ac level is relatively low 4 20 Normally the ac input must be above a certain minimum potential before a triac will conduct However 2 1 and C2 and A2R1 and R2 provide a holding current that allows the triac to conduct at any time during the ac input cycle RFI choke A2L1 slows down the turn on of the triac in order to minimize spikes at the output of the supply The components of the A2RFI Filter Assembly all mounted inside a shielded box to minimize radiated and reflected Further RF suppression is provided by line bypass capacitors 4 21 The preregulator control circuit samples the input line voltage the dc input to the series regulator and the volt age across the series regulator transistors generates firing pulses that fire the triac and adjusts the phase of these pulses so that the dc voltage across the series regulator remains constant 4 22 The inputs to the contro circuit are algebraically summed across capacitor C70 Ail inputs affect the time AC INPUT TO SUPPLY HIGH AC INPUT TO TRANSFORMER LATER V FIRING P
133. s option includes Options 007 and 008 in the same instrument 027 010 Chassis Slides Factory installed slides permit convenient access to the interior of a rack mounted supply for maintenance 013 Three Digit Graduated Decadial Voltage 040 Control To improve mechanical stability and permit accurate resetting of the output voltage Option 013 replaces the coarse voltage control with a ten turn control equipped with a 3 digit turns counting dial 014 Three Digit Graduated Decadial Current Control To improve mechanical stability and permit accurate resetting of the output current Option 014 replaces the coarse current contro with a ten turn control equipped with a 3 digit turns counting dial 016 Rewiring for 115Vac 10 Single Phase Input Model 6260B only This factory modification replaces the circuit breaker and power transformer adds a resistor to the Description Adjustable Voltage Programming Two screwdriver adjustable controls accessible through holes in the rear panel allow the voltage programming coefficient and zero output voltage to be adjusted conveniently to an accuracy of 0 1 Adjustable Current Programming Two screwdriver adjustable controls accessible through holes in the rear panel allow the current programming coefficient and zero output current to be adjusted conveniently to an accuracy of 0 196 Adjustable Voltage and Current Programming This option includes Options 020 and 021 i
134. s regulator CV CC load regulation 40106 A40108 or 40110 as applicable Preregulator Output voltage R70 See para 5 102 CR1 CR20 CV CC OR gate CV CC crossover operation CR2 CR3 Voltage clamp circuit CC load regulation CR4 CR40 Temperature stabilizing diodes Temperature coefficient CR41 Limiting diodes CV CC load regulation CR35 CR36 Turn on circuit Preregulator and series regulator CR37 turn on delay CR43 45 Bias supply 11V and 2 4V bias voltages thru CR49 CR53 54 CR44 CR50 Driver and error amplifier Down programming speed CV CC load regulation CR70 CR71 Overvoltage limit circuit Limiting action and level CR72 thru Preregulator control Output voltage ripple imbalance and R70 R82 See para CR84 CR88 preregulator waveforms 5 100 and 5 102 CR7 CR60 Reference regulator 12 4V 6 2V and 6 2V reference CR61 CR62 voltages CR90 thru Crowbar Trip voltage voltage across series regulator R95 A5R125 See CR93 when crowbar is tripped supply stability para 5 104 and 5 106 AACR108 4 110 A4CR101 and Main rectifier diodes Voltage across main filter capacitors AACR102 or A4CR101 thru AA4CR104 5 14 Table 5 8 Checks and Adjustments Required After Semiconductor Replacement Continued REFERENCE FUNCTION OR CIRCUIT ADJUST 105 and AACR106 Reverse voltage protection Voltage clamp circuit
135. sired 3 14 When adjusting the crowbar trip point the possibility of false tripping must be considered If the trip voltage is set too close to the supply s operating voltage a transient in the output would falsely trip the crowbar For this reason it is recommended that the crowbar be set higher than the output voltage by 596 of the output voltage plus 2 volts for the Models 6259B 6260B or 6261B or 5 of the output voltage plus one volt for the Models 6268B 6269B If an occasional tripping of the crowbar can be tolerated as a load is being disconnected the crowbar trip point can be set much closer to the operating voltage of the supply 3 15 Connecting The Load 3 16 To satisfy the requirements of safety the wires to the load should be at least heavy enough not to overheat while carrying the power supply current that would flow if the load were shorted Generally heavier wire than this is required to obtain good regulation at the load If the load regulation is critical use remote voltage sensing Refer to paragraph 3 27 3 17 If multiple loads are connected to one supply each load should be connected to the supply s output terminals using separate pairs of connecting wires This minimizes mutual coupling effects between loads and takes full advantage of the supply s low output impedance Each pair of connecting wires should be as short as possible and twisted or shielded to reduce noise pickup 3 18 If load considerati
136. stant voltage constant current operation with local sensing and local programming This strapping pattern is illustrated in Figure 3 2 By means of the front panel voltage and current controls the operator selects either a constant voltage or a constant current output Whether the supply functions in the constant voltage or the constant current mode depends on the settings of the voltage and current controls and on the resistance of the output load For values of load resis tance greater than a critical crossover value equal to the voltage setting divided by the current setting the supply operates in the constant voltage mode With a load resis tance smaller than this critical value it operates in the constant current mode The transition occurs automati cally no switches need to be operated or connections changed 32 EXT CROWBAR TRIGGER AI 2 A4 AS AG 7 AB S S AD 223 21990 Figure 3 2 Normal Strapping Pattern 3 8 Constant Voltage Operation 3 9 To adjust the supply for constant voltage operation a Turn on supply and with output terminals open adjust the VOLTAGE controls for the desired output voltage Then turn power off b Connect a short across the rear panel output terminals restore power and adjust the CURRENT controls for the desired maximum output current Then remove the short If a load change causes this current limit to be excee
137. stor A2R3 on the circuit board Refer to Option 026 in the Table 6 4 parts list for its description and HP Part Number Replace cover on RFI assembly d Locate the wire that connects circuit breaker CB1 to the A3T2 bias transformer terminal marked 230 disconnect it from the transformer and reconnect it to the terminal marked 115V Also disconnect the wire from fan B2 not used in the 6259B from the terminal marked 230V and reconnect it to the terminal marked OV see Fig 2 2C e Re install the RFI assembly by reversing the procedure of step b f Unsolder the jumper connecting terminals 2 and 3 of power transformer T1 see Fig 2 3C and solder jumpers between terminals 1 and 3 and 2 and 5 2 26 Converting a Standard Instrument to 115 Volt Operation Model 6260B 2 27 To convert the standard Model 6260B to 115 volt operation proceed as follows a Obtain and install a new power transformer T1 and a new circuit breaker Refer to Option 016 in the Table 6 4 parts list for their description and HP Part Number The new transformer has two primary terminals Transfer the wire from the OV terminal on the old trans former to the OV on the new one and from the 230V terminal on the old one to the 115V terminal on the new one The connections to the replacement circuit breaker are the same as to the old one b Perform steps b through e of paragraph 2 25 2 28 Converting a Standard Instrumen
138. sufficiently charged CR35 becomes reverse biased and the preregulator control circuit is permitted to fire the triac 4 60 Diode CR36 performs a similar function for the series regulator This diode initially couples a positive voltage to Q41 which inverts it and applies it to the series regulator This negative voltage keeps the regulator cut off until C35 charges up Diode CR37 provides a discharge path for C35 when the supply is turned off 4 61 Reference Regulator 4 62 The reference circuit is a feedback power supply similar to the main supply It provides stable reference voltages used throughout the unit All the regulated reference voltages are derived from dc obtained from full wave rectifier CR61 and CR62 and filter capacitor C61 Zener diodes VR60 and VR61 establish well regulated poten tials of 6 2 and 6 2V with respect to common point S while the regulator circuit establishes a well regulated potential of 12 4 volts Resistor R63 establishes an optimum bias current through the zener diodes 4 63 The regulating circuit consists of series regulating transistor Q60 driver O61 and differential amplifier 062 and Q63 The voltage across zener diodes VR60 and VR61 is compared to the voltage across resistor Z2J and any difference is amplified by Q62 and Q63 The error voltage thus appearing at the collector of Q62 is amplified by driver stage Q61 and applied to series regulator Q60 in the correct phase and amplitude to maint
139. supply to the negative terminal of the battery Connect Ry between the negative terminal of the supply and the positive terminal of the battery rotate the supply s current control fully counterclockwise CCW energize the supply and set the current control for the desired discharge current as indicated on the front panel meter 3 14 EXT CROWBAR TRIGGER A A A4 A5 A6 A7 A8 S S A9 elelelelele 7 BATTERY INITIAL BATTERY VOLTAGE CONSTANT DISCHARGE CURRENT Eg MAX RATED VOLTAGE OF SUPPLY Ry MINIMUM Ip Es MINIMUM RxIp Figure 3 17 Battery Discharging SECTION IV PRINCIPLES OF OPERATION REFERENCE SUPPLY RECTIFIER BIAS SUPPLY a FORMER FILT PREREG ULATOR CONTROL CIRCUIT ER RE JOVERVOLT A LIMIT CIRCUIT NOTE PROTECTION SERIES DRIVER CONSTANT CURRENT COMPARATOR SHORT CIRCUIT CURRENT CONTROLS A4RI23 CURRENT SAMPLING RESISTOR MIXER amp ERROR AMPL CONSTANT VOLTAGE COMPARATOR OVER VOLTAGE PROTECTION CROWBAR L CIRCUIT GE M DENOTES CONSTANT VOLTAGE FEEDBACK PATH DENOTES CONSTANT CURRENT FEEDBACK PATH Figure 4 1 Overall Block Diagram 4 1 OVERALL BLOCK DIAGRAM DISCUSSION 4 2 The major circuits of the power supply are shown on the overall block diagram of Figure 4 1 The ac input to the power
140. t practicable wire gauge at least heavy enough to limit the voltage drop in each lead to 0 5 volt This limitation is dictated by the adverse effect that a greater load lead voltage drop has on bias voltages within the supply when remote sensing is used Twisting the load leads may help to minimize noise pick up While there are practical limitations on the distance that can separate a power supply from its load when using remote sensing it isn t possible to define these limits precisely due to a variety of factors that are unique to each particular installation EXT CROWBAR TRIGGER A2 4 A5 A7 AB S S A9 ojo Figure 3 3 Remote Sensing 34 3 31 Since the sensing leads carry only a few milliamps the wires used for sensing can be much lighter than the load leads 22 AWG is generally adequate but they should be a shielded twisted pair to minimize the pickup of external noise Any noise picked up on the sensing leads will appear at the supply s output The shield should be grounded at one end only and should not be used as one of the sensing conductors The sensing leads should be connected as close to the toad as possible 3 32 The sensing leads are part of the supply s program ming circuit so they should be connected in such a way as to make it unlikely that they might inadvertently become open circuited If the sensing leads were to open during Operation the output voltage w
141. t source the input current is approxi mately twice that shown in paragraph 2 15 232 REPACKAGING FOR SHIPMENT 2 33 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 contact your local Hewlett Packard field office to obtain the materials This office will also furnish the address of the nearest service office to which the instrument can be shipped and provide the Authorized Return label necessary to expedite the handling of your instrument return Be sure to attach a tag to the instrument which specifies the owner model number full serial number and service required or a brief description of the trouble 2 4 INPUT POWER TRANSFORMER TI CONNECTIONS FOR 230 VOLT OPERATION B INPUT POWER TRANSFORMER TI CONNECTIONS FOR 208 VOLT OPERATION Figure 2 4 Power Transformer T1 Primary Connections for 208Vac Operation Model 6260B and 6269B SECTION III OPERATING INSTRUCTIONS Figure 3 1 Front Panel Controls and Indicators 3 1 TURN ON CHECKOUT PROCEDURE CAUTION 3 2 The following steps describe the use of the front Do not interchange the ac and acc input lines panel controls and indicators illustrated in Figure 3 1 and connect the ac input terminal to the hot side serve as a brief check that the supply is operational This and the acc input terminal to the grounded c
142. t this point e Remove mounting nuts from A4CR106 and A4CR107 on left side of heat sink and from 4 108 on right side of heat sink Remove mounting nuts bolts and shoulder washers from transistor A40102 on right side of heat sink see Figure 7 5 f Slide this section of heat sink forward and off insulating rods g Remove four screws holding emitter resistor circuit board to adjoining heat sink section Access is now provided to series regulator emitter resistors A4R150 through A4R165 see Figure 7 9 h To remove emitter resistor circuit board completely unsolder connections to board marking wires to permit proper replacement 5 68 Interconnection Circuit Board Removal To replace capacitor A3C3 or transformer A3T2 shown in Figure 7 2 it is necessary to remove the interconnection Circuit board by following the following procedure a Remove main circuit board RFI assembly and heat sink assembly as described in paragraphs 5 62 5 65 and 5 66 b Remove six screws holding back panel to chassis frame Stand supply on left side and remove two screws holding main circuit board support tray to back panel Move panel away from frame d Remove two screws holding main circuit board support tray to internal chassis divider e Working from top rear of supply interconnection circuit board still attached to main circuit board support 5316 tray can be angled up enough to allow access f lf necessary to c
143. t to 50Hz Operation 2 29 convert 60 2 instrument to 50Hz operation proceed as follows a Replace ATR82 with a 240 ohm 5 1 2 watt resistor Refer to the Table 6 4 parts list under Option 005 for the HP Part Number of a suitable replacement b After replacing A1R82 perform the prereguiator tracking adjustment given in Paragraph 5 102 Check the ripple balance adjustment by the procedure given in paragraph 5 100 2 3 INPUT POWER TRANSFORMER TI PRIMARY CONNECTIONS FOR 230 VOLT OPERATION B INPUT POWER TRANSFORMER TI PRIMARY CONNECTIONS FOR 208 VOLT OPERATION INPUT POWER TRANSFORMER TI PRIMARY CONNECTIONS FOR 115 VOLT OPERATION Figure 2 3 Power Transformer Primary Connections for 208Vac and 115Vac Operation Model 6259B 6261B and 6268B 2 30 INPUT POWER CONNECTIONS 2 31 No input power cable is supplied with the instru ments covered by this manual Input power connections are made to a 3 terminal barrier block on the rear panel Its center terminal is grounded to the instrument chassis To protect operating personnel the National Electrical Manufacturers Association NEMA recommends that the instrument panel and cabinet be grounded The user supplied power cable shou d have three conductors with the third conductor grounded and should be of adequate wire size to handle the input current drawn by the supply see paragraph 2 15 Note that when the supply is opera ted from a 115 vol
144. ternal source is allowed to pump current into the supply it will cause a loss of regulation and might possibly damage the output capacitor To avoid these effects it is necessary to pre load the supply with a dummy load resistor so that it delivers current through the entire operating cycle of the load device 3 87 Battery Charging 3 88 The automatic crossover between constant voltage and constant current exhibited by these supplies makes them ideal for battery charging applications Using this EXT CROWBAR TRIGGER 2 A4 5 A6 AT A8 5 A9 o o MASTER A A2 A3 4 5 6 S S AD SLAVE GND R 20 Al 2 4 5 6 AT S OPTIONAL CROWBAR INTERCONNECTIONS SEE PARA 3 72 3 73 SLAVE NO 2 Figure 3 15 Auto Tracking Operation of Three Units feature battery may be charged at a constant current until the maximum charge voltage is reached at which point the supply reverts to constant voltage operation and continues to supply a trickle charge current sufficient to maintain full charge Thus the charging operation can be unattended after properly setting the charging rate and maximum charge voltage and connecting the battery to the output terminals of the supply CAUTION Any time these supplies are used to charge a battery be sure to install a prot
145. tion 3 52 Use the rear pane interconnections shown in Figure 3 10 or 3 11 to auto parallel two or three supplies This mode of operation provides a greater current capacity than can be obtained from a single supply while maintain ing nearly equat load sharing among the paralleled suppties under all load conditions Supplies having the same mode number make the most practical auto parallel combinations but any of the supplies included in this manual that have equal current ratings may be used NOTE Use wires of equal length and gauge to connect each auto paralleled supply to the load Load sharing accuracy is affected unless the positive leads connecting each supply to the load are all equal in resistance 3 53 Setting the Voltage and Current Controls The auto parallel combination of two or three supplies behaves as if it were a single constant voltage constant current supply controlled by the voltage and current controls of the master supply The voltage controls of the slave s are disabled but their current controls remain operative and must be set to maximum to prevent a slave supply from independently reverting to constant current operation as would occur if the output current setting of the master supply exceeded that of a slave EXT CROWBAR TRIGGER 2 4 5 S S AS ejelelgl le R R 5 GAIN p CONTROL VOLTAGE SOURCE Eg MAX RR 225mA Ras
146. transformer is preregulated by a triac which forms a feedback loop in conjunction with the preregulator control circuit This feedback loop maintains a low and constant voltage drop across the series regulator in order to minimize dissipation in the series regulator transistors 4 3 To accomplish this the prereguiator control circuit issues a phase adjusted firing pulse to the triac once during each half cycle of the ac input The control circuit continuously samples the input line voltage the dc input to the series regulator and the voltage across the series regulator On the basis of these inputs it controls the time at which each firing pulse is generated 44 44 The output of the triac preregulator is stepped down by the power transformer full wave rectified and filtered The resulting preregulated dc voltage is applied to the series regulator which varies its conduction to provide a regulated voltage or current at the output terminals 4 5 The series regulator is part of another feedback loop which consists of the error and driver amplifiers the constant voltage comparator and the constant current comparator The series regulator feedback loop makes rapid low magnitude adjustments to the output while the preregulator feedback loop handles large relatively slow regulation demands 46 The feedback signals that control the conduction of the series regulator originate in the constant voltage or constant current comparator Du
147. tter combination that denotes the date of a significant design change and the country of manu facture The first two digits indicate the year 10 1970 11 1971 etc the second two digits indicate the week and the letter designates the U S A as the country of manufacture The second part is the power supply serial number different sequential number is assigned to each power supply starting with 00101 1 14 If the serial number on your instrument does not agree with those on the title page of the manual Change Sheets supplied with the manual define the differences between your instrument and the instrument described by this 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 Specify the model number serial number prefix and HP part number shown on the title page Table 1 1 Specifications Models 6259B 6260B 6261B 6268B 6269B INPUT 230Vac 10 single phase 57 63Hz for the standard models For other input voltages or 50Hz operation see the option listings in paragraph 1 10 Input power require ments are listed in paragraph 2 15 OUTPUT Model 6259B 62608 62618 62688 6269 0 10 volts at 0 50 amps 0 10 volts at 0 100 amps 0 20 volts at 0 50 amps 0 40 volts at 0 30 amps 0 40 volts at 0 50 amps LOAD EFFECT LOAD REGULA
148. twork 2 RFI Filter Ass y Electrical Note 1 fxd paper 0 1uF 250V fxd paper 047uF 250Vac fxd cer 5000pF 1kV thyristor Si Triac omit for 230Vac or 208Vac operation jumper for 230Vac operation nearest commercial equivalent 6 8 MFG PART NUMBER C42S GB 1815 BWH EB 3925 EB 5115 CEA T 0 CEA T 0 EB 2045 EB 47G5 EB 1005 EB 1035 110 CEA T 0 CEA T 0 CEA 0 CEA T 0 CEA T 0 CEA T 0 CEA T 0 CEA 0 0 110 EB 1015 CCA 993 2 10939 74 14825 2 10939 122 3026 C023B102G502Z 31 T6440M HP PART NUMBER 0698 3637 0689 1815 0811 1763 0686 3925 0686 5115 0757 1093 0757 0427 0686 2045 0698 0001 0686 1005 0686 1035 2100 0439 0757 0421 0757 1099 0757 0422 0757 0274 0757 0427 0698 4443 0757 0442 0698 4484 0698 4590 2100 0439 0686 1015 0758 0005 5080 7192 1902 3070 1902 1221 1902 0049 1820 0240 1810 0042 0160 4065 0160 4323 0160 0899 1884 0248 Table 6 4 Replaceable Parts REF DESIG AND MODELS L1A L1B 6259B 60B 61B 68B Li 62698 R1 2 R3 R4 C3 6259B 60B 618 6268B 69B J1 R120 T2 B1 C14 6259B 61B 68B 69B C5 6259B 61B 68B 69B 101 102 62598 62608 6261 68B 69B CR103 104 6259B 6261B 68B 69B CR105 CR106 CR107 6260B CR108 CR110 0101 0102 62598 60B 61B 62688 69B Q103 106 62598 60B 61B 6268 698 DESCRIPTION inductor
149. upply In this mode the output voltage varies in a 1 to 1 ratio with the program ming voltage The load on the programming voltage source is less than 20 microamperes Impedance matching resistor Rx is required to maintain the temperature coefficient and stability specifications of the supply To adjust the output voltage to exactly zero with a zero programming voltage follow the same instructions as are referred to in paragraph 3 40 3 42 Constant Voltage Output Voltage Input Variable Gain In the remote programming arrangement shown in Figure 3 6 the series combination of external voltage source and reference resistor Rn replaces the supply s internal voltage programming current source As a result the voltage this external current source develops across gain contro Rp becomes the output voltage of the supply and the gain relationship between and the output volt age equals the resistance ratio Rp Rg EXT CROWBAR TRIGGER Al 2 4 5 6 A7 AB 5 S AS E Rx VOLTAGE SOURCE 3 INCLUDING INTERNAL IMPEDANCE CF VOLTAGE SOURCE Figure 3 5 Voltage Programming of Output Voltage Unity Gain 36 3 43 When using this programming technique select a value for Rp that is less than 10k ohms and that would conduct at least 5 milliamps if connected across the programming voltage source with its voltage at the maximum value of input voltag
150. v Mountain View Calif Breeze Corporations Inc Union N J Reliance Mica Corp Brooklyn N Y Sloan Company The Sun Valley Calif Vemaline Products Co Inc Wyckoff N J General Elect Co Minature Lamp Dept Cleveland Ohio Nylomatic Corp Norrisville RCH Supply Co Vernon Calif Airco Speer Electronic Components Bradford Pa Hewlett Packard Co New Jersey Div Rockaway N J General Elect Co Semiconductor Prod Dept Buffalo N Y General Elect Co Semiconductor Prod Dept Auburn N Y amp Components Inc Newton Mass Burndy Corp Norwalk Conn Wagner Electric Corp Tung Sol Div CTS of Berne Inc Chicago Telephone of Cal Inc So Pasadena Calif Boone N C Newark N J Camden N J Cincinnati Ohio Lake Mills Wisconsin Dover N H Bloomfield N J Berne Ind IRC Div of TRW Inc General Instrument Corp Philadelphia Handle Co U S Terminals Inc Hamlin Inc Clarostat Mfg Co Inc Thermalloy Co Dallas Texas Hewlett Packard Co Loveland Colo Cornell Dubilier Electronics Div Federal Pacific Electric Co Newark N J General instrument Corp Semicon ductor Prod Group Hicksville N Y Fenwal Elect Framingham Mass Corning Glass Works Raleigh N C Table 6 3 Code List of Manufacturers CODE MANUFACTURER ADDRESS cope MANUFACTURER ADDRESS Delco Radio Div of General Motors Corp Kokomo Ind Atlantic Semiconductors Inc Asbury Park N J Fairchild Camer
151. ville N J 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 Burns 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 Warner Corp Bridgeport Conn 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 Indianapolis Ind Semoor Div Components Inc Phoenix Arizona Robinson Nugent Inc New Albany N Y Torrington Mfg Co Van Nuys Calif 62 Use Code 28480 assigned to Hewlett Packard Co Palo Alto California MANUFACTURER ADDRESS Transistor Electronics Corp Minneapolis Minn Westinghouse Electric Corp Elmira N Y Fairchild Camera and Instrument Mountain View Calif Birtcher Corp The Los Angeles Calif Sylvania Electric Prod Inc Mountainview Calif IRC Div of TRW Inc Burlington lowa Continental Device Corp Hawthorne Calif Raytheon Co Components Di
152. volt instruments to 208 volt operation proceed as follows a Perform steps a through d of paragraph 2 21 b Unsolder the wire connected to the terminal marked 230 on power transformer T1 and solder it instead to the terminal marked 208V see Fig 2 4 2 24 Converting a Standard Instrument to 115 Volt Operation Models 6259B 6261B and 6268B ASRI20 51K ASDSI LINE ON ASRI20 ASDSI LINE ASDSI NOTE X FAN B2 IS NOT USED IN MODEL 62598 A BIAS TRANSFORMER 2 CONNECTIONS FOR 230 VOLT OPERATION B BIAS TRANSFORMER A3T2 CONNECTIONS FOR 208 VOLT OPERATION c BIAS TRANSFORMER A372 CONNECTIONS FOR 15 VOLT OPERATION Figure 2 2 Bias Transformer Primary Connections for 208Vac Operation Model 6259B 6260B 6261 6268B and 6269B and 115Vac Operation except Model 6269B 2 25 To convert these 230 volt instruments to 115 volt operation proceed as follows Omit this step for the Model 62598 Obtain and install a new circuit breaker CB1 Refer to Option 028 in the Table 6 4 parts list for its current rating and HP Part Number Connections to the replacement are the same as those to the original breaker b Remove and partially disassemble the A2 assembly as described in steps a through d of paragraph 5 65 c Unsolder jumper J3 from the A2 circuit board see Fig 7 1 and install jumpers J1 and J2 Also install resi
153. y present on the output of an HP supply is 120Hz due to full wave rectification an oscilloscope display showing a 120Hz fundamental component indicates a clean measurement setup while the presence of a 60Hz fundamental usually means that an improved setup will result in a more accurate and lower value of measured ripple OSCILLOSCOPE CASE POWER SUPPLY CASE L A INACCURATE METHOD USING SINGLE ENDED SCOPE GROUND CURRENT IG PRODUCES 60 CYCLE DROP IN NEGATIVE LEAD WHICH ADDS TO THE POWER SUPPLY RIPPLE DISPLAYED ON SCOPE METHOD MAY BE ADEQUATE UNDER CERTAIN CONDITIONS SEE TEXT POWER SUPPLY CASE OSCILLOSCOPE CASE VERTICAL INPUT B RECOMMENDED METHOL SING A DIFFERENTIAL SCOPE WITH FLOATING INPUT GROUND CURRENT PATH IS BROKEN COMMON MODE REJECTION OF DIFFERENTIAL INPUT SCOPE IGNORES DIFFERENCE IN GROUND POTENTIAL OF POWER SUPPLY amp SCOPE AND SHIELDED TWO WIRE FURTHER REDUCES STRAY PICK UP ON SCOPE LEADS Figure 5 2 Ripple Test Setup 5 19 Although the method shown in Figure 5 2 is not recommended for ripple measurements it may prove satisfactory in some instances provided certain precautions are taken One method of minimizing the effects of ground current flow 1g is to ensure that both the supply and the test instrument are plugged into the same ac power bus 5 20 To minimize pickup a twisted pair or preferably a shielded two wire cable should be used to connect the sensing terminals of the powe

Download Pdf Manuals

Related Search

Related Contents

TB-7Z-ISDK Hardware User Manual  MODÈLES 27XL ET 121XL MODELOS 27XL Y  TAPPETO/BATTERIA TAPETE LÚDICO COM CONJUNTO DE  MU-001-4.0 MANUAL DE USUARIO BATEC_EN-DEF  Manuel d`instruction HTST1800  D-Link DSL-300 User's Manual  Kaidan Tripod User's Manual  CSBOT USER GUIDE - RoboCupJunior Cospace UK  

Copyright © All rights reserved. Failed to retrieve file