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HP 6012A User's Manual

1. REMOTE TRIP REMOT 8 IN i gt F ai Pulse duration Reset time 125 us minimum Set up time 25 us minimum OVP Clear delay to 6012A mainframe 1 sec 30 POWER ON PRESET Output ratings Open collector output referred to power supply common Maximum output voltage logic high 16 V Logic low output 0 4 V maximum at 8 mA POWER ON PRESET pulse timing 15 us minimum POWER OFF LOW BIAS OR AC DROPOUT 5V REG POWER ON PRESET Wait time after LOW BIAS OR AC DROPOUT indication Tw 750 ms maximum Pulse duration after 5 V REG has stabilized Tp 10 ms minimum BIAS SUPPLIES DC output ratings 0 to 55 C t1 396 at 100 mA 15 V 1 5 75 mA 15 V 2 596 at 75 mA Short circuit output current 5V 170 mA 15 15 V 125 mA 15 15 V 125 mA 2096 Load and Source Effect Change in output voltage for a load change equal to the maximum available current rating of the supply plus any line voltage change within rating 2 596 15 V 3 096 15V 1 096 PARD typical 5V 2 RMS 15 3mV RMS 15 V 3mV RMS ISOLATION Status Indicator lines and Remote Control lines may be floated a maximum of 600 VDC from ground from the power supply output or from each other These lines may not be con nected to any primary circuits
2. uo MG 130 8 A9 162 135338 NO M3MDd nf 9 31038 I ban 5108 EUNIS 30 diui i E i 13535 310W3H 16c 598 HOLUY G8 30HINOS ot mur eA Era P aaa a ANAYA APPENDIX 100 Vac INPUT POWER OPTION 100 B 1 GENERAL INFORMATION B 2 Description B 3 Option 100 is a modification of Model 6012A that in volves changing the values of two resistors located in the Overvoltage Protection and Display Circuits also entails recalibrating the unit and changing the Voitmeter Ammeter and the Front panel These changes allow the unit to operate at a lower line voltage of 90 105 Vac while operating on the same line frequency of 48 to 63 Hertz The reduced input voltage limits the output power to 675 W and the output voltage from 0 to 50 V while retaining the standard unit s out put current rating Other parameters that change due to Op tion 100 include the Overvoitage Trip Range and The Remote Programming specifications B 4 Scope of Appendix B B 5 This appendix contains all the information necessary to support Model 6012 power supplies that are equipped with Option 100 The appendix describes only the changes pertaining to Option 100 and how they affect the other por tions of this manual Unless otherwise specified in Appendix B
3. i cers LL a M de CES 34 i HEWLETT hp PACKARD ZL09 U 7 HEWLETT CERTIFICATION Hewlett Packard Company certifies that this product met its published specifications at the time of shipment from the factory Hewlett Packard further certifies that its calibration measurements are traceable to the United States National Bureau of Standards to the extent allowed by the Bureau s calibration facility and to the calibration facilities of other International Standards Organization members WARRANTY This Hewlett Packard instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment During the warranty period Hewlett Packard Company will at option either repair or replace products which prove to be defective For warranty service or repair this product must be returned to a service facility designated by HP Buyer shall prepay shipping charges to HP and HP shall pay shipping charges to return the product to Buyer However Buyer shall pay all shipping charges duties and taxes for products returned to HP from another country HP warrants that its software and firmware designated by HP for use with an instrument will execute its programm ing instructions when properly installed on that instrument HP does not warrant that the operation of
4. terminal strip must be strapped as shown in Figure 3 3 The front panel VOLTAGE and CURRENT controls must be turned fully CW to avoid loading the 002 current programming circuit With the CURRENT PROG ENABLE lines J2 11 and J2 12 low relays K2 and K1 are closed and remote programming is enabled Opening the CURRENT PROG ENABLE lines high logic level returns control to the front panel pots CAUTION When switching to local control output voltage and current will go to full scale Rernember to set the VOLTAGE and CURRENT controls to safe levels before switching to local control and remember to turn the VOLTAGE and CURRENT controls fully CW after returning to remote con trol Once the system has been checked out remove the straps from 8 A7 and and from A4 and 2 and program the system remotely A 65 Bias Supplies A 66 The outputs of three current limited bias supplies are available for user supplied circuitry These are 15 75 mA at J2 4 15 V 75 mA at J2 20 and 5 V 9 100 mA at 2 23 all with respect to J2 7 power supply common A 10 Six screwdriver adjustable pots located at the top of the op tion board set the output voltages and current limiting points of these supplies refer to Specification Table A 1 CAUTION Although the bias supplies are current limited it is important to avoid shorting the 15 V supplies to common These supplies are used internally for the
5. CONSTANT CURRENTICC i 1 i i Isa 132 IOUT 9 Eg VOLTAGE CONTROL SETTING 1 CURRENT CONTROL SETTING fios ES CROSSOVER VALUE OF LOAD RESISTANCE Figure 3 4 Overall Output Range with Three Sample Operating Loci 3 22 Locus 2 is established with VOLTAGE setting of 40V and a CURRENT setting of 30A Its crossover load resistance is 1 3 ohms and lies on the rated output power boundary 3 23 A rectangular operating locus will be established for voltage and current settings within the rated output power boundary and the load resistance determines where on that locus the power supply operates However if the VOLTAGE and CURRENT controls are set so that the boundary can be exceeded as in locus 3 the supply will go into overrange if the load resistance falls within a critical band refer to next paragraph 3 24 Overrange The supply will be driven into overrange shaded area of Figure 3 4 if the VOLTAGE and CURRENT controls are set above the output power rating and the load resistance falls within a cr tical band For example assume that the operator sets the VOLTAGE control at 50V and the CURRENT control at 40A as in locus 3 on Figure 3 4 For all load resistances above 2 2 ohms which is the critical value the supply would operate in the constant voltage mode the load resistance were to fall much below 2 2 ohms however the supply would be forced
6. RD NO NM 9 b MN M Table A 3 Replaceable Parts Ref Mfr Desig Sd No Description Code Mfr Part No cap 100pF 596 300 V mica cap 1000pF 596 100 V cer cap 5000 20 100 V cer cap 1uF 20 80 50 V cer cap 270pF 596 300 V mica cap 01 1096 100 V cer cap 1 84 10 20 V cap 330pF 596 500 V mica cap 4700pF 1096 200 V 22uF 10 50 50 V cap 0154F 20 20pF cap 500uF 75 10 40 V al cap 1 2096 50 V cer 10004F 75 10 25 V al cap 2200pF 1096 100 V cer cap 0224 10 100 V cer cap 4 7 10 35 V dio pwr rect 200 V 1 dio gen prp dio sw 80 V 200 mA connector F 37 pin relay reed XSTR NPN si XSTR PNP si res 2000 596 25W fc res 1 5k 596 5W fc res 4700 596 25W fc res 3 3m 596 25W fc res 8 25k 196 125W f res 4300 596 25W fc res 2 5k 1 125W f res 1M 596 25W fc res 1k 596 3W w res 10k 596 25W fc res 1 5k 196 125 res 4 7k 596 25W fc res 33k 596 25W fc res 9 k 1 125 W f res 100k 1 125W f res 20k 1 125W f res 15k 5 25W fc res 2700 5 25W fc res 270k 596 25W fc res 1 33k 196 125W f res 160 596 25W fc res 2 7k 5 25W fc res 90 90 1 125W f res 562k 1 125W f A 14 XX03COG102J100A 835 100 250 502 292CZ5U 1042050C CACOS3X7R103K100A 150D185X9020A2 192P47292 PME271Y515 04 78104 050 CACO2X7R222K100A CACOAX7R223K100A 150D475X903582 DYS A14B FDH3369
7. gt A cA A A A 4 o o Q0 Description res 5 1k 596 0 25W fc res 1k 5 0 25W fc res 5 1M 596 0 25W fc res 2 67K 196 0 125W f res 22M 596 0 25W fc res 2k 596 0 25W fc res 33k 596 0 25W fc res 17 8k 196 0 125W f res 562k 196 0 125W f res 3 9k 596 0 25W res 2 87k 1 0 125W f res 9090 1 0 125W f res 5 62k 196 0 125W f res 63k 196 0 125W f res 2 15k 196 0 125W f res 7500 1 0 125W f res 2700 5 0 25W fc res 7 5k 1 0 125 f res 4 02k 1 0 125W f res 1 5k 196 0 125W f res 3019 1 0 125W f res 22 1k 0 596 0 125W f res 3 01k 196 0 125W f res 34 8k 1 0 125W f res 22k 596 0 25W fc res 6 98k 196 0 125W f res 3 57k 1 0 125W f res 2 49k 196 0 125W f res 1 07k 196 0 125W f res 196k 0 596 0 125W f res 221k 196 0 125W f res 6 19k 196 0 125W f res 4 32k 196 0 125W f res 1 43 1 0 125W 1 res 200k 196 0 125W f Term Block 10 Term IC Op Amp Dual IC Op Amp Dual IC Op Amp IC 324 Op Amp Quad Comparator Quad Buffer 2 IN NAND Quad IC D Type FF 3 AND Triple IC Counter TTL Muitivibrator Dual Comparator Quad IC Voitage Reg xstr array NPN si op amp 6 6 Table 6 4 Replacement Parts continued 91637 91637 24546 24546 01121 91637 24546 24546 91637 91637 24546 24546 24546 24546 27014 04713 27014 27014 27014 01295 01295 27014 01295
8. 1645 EB1005 CB2035 EB4715 RS 5 NK4H 11E 1060 SDA10254 21 SOC 156 WOA Special 04713 5230016 110 04713 5230016 204 C1 51 52 C2 23 C3 8 53 4 6 9 14 20 21 25 28 30 33 36 38 7 57 10 22 11 18 C12 C13 C15 C16 17 C19 C24 42 C26 C27 C31 49 C32 C34 35 C39 40 C41 CR1 3 7 9 12 15 17 19 22 30 CR2 4 6 8 10 11 16 20 21 41 2 11 3 2 Q1 02 3 5 7 9 10 04 08 011 012 R1 2 4 6 18 19 R3 48 51 74 102 105 106 129 R7 25 HP Part No 0180 0230 0160 4557 0160 0128 0160 4722 0140 0203 0160 4741 0160 0163 0160 0159 0160 0127 0180 0218 0160 0162 0160 2036 0160 0194 0180 0137 0180 1980 0180 0405 0140 0149 0140 0199 0160 3070 0160 0134 0180 0550 0180 0291 0140 0200 0160 0174 0160 2215 0160 2639 0160 2496 0140 0210 1901 0050 1901 0033 1200 0507 9140 0210 9140 0131 1855 0413 1854 0823 1853 0086 1853 0041 1854 0448 1854 0585 0686 1035 0683 4725 0683 3355 TQ N ONAN Table 6 4 Replacement Parts continued Description Control Board Assembly cap 14 2096 50V cap 0 1nF 20 50V cer cap 2 24F 2096 50V cap 80 2096 50V cer cap 5 500V mica 0 224F 1096 50V cer cap O334F 1096 200V cap 6800pF 1096 200V poly cap 1 20 25V cer cap 0 15uF 1096 35V cap 0224F 10 200V poly cap 4300pF 596 500V mica
9. 1 14093 IC MC14023BCP IC Voltage Reg 5 V IC Voltage Reg Adi Pos IC Voltage Reg Adj Neg dio znr 20 V 596 dio znr 6 5 V 296 dio znr 7 5 V 596 dio znr 11 8 V 2 dio znr 11 8 V 596 res array 1 5k 296 res array 10k 296 A 15 Mfr Part No 4 1 8 1003 4 202 4 100 4 103 2225 C4 1 8 TO 5111 F CB4735 EB 1205 CB1025 CB33G5 C4 1 8 TO 6811 F CB6235 CB3305 CB27G5 C4 1 8 TO 215R F CB3325 CB1525 5135068 CA3081E SC45023PK 5 42853 5 45115 5 45057 45010 7805UC UA723CJ MLM2046 5211213 227 5211594 5230016 204 5211213 161 2104152 208 103 3 Replaceable Parts cont Ref HP Mfr Desig Part No Qty Description Code Mfr Part No OPTION BOARD ASSEMBLY 06012 60005 1 cable assy 16 conductor with connectors MECHANICAL 1205 0398 3 heat sink al Q5 7 1251 4150 1 connector 37 pin M 1251 6069 37 contacts crimp 1251 6070 1 shield and hardware for 37 pin connector 2360 0411 2 6 32 screw 06024 00014 1 bracket J2 1251 5436 1 screwlock J2 MISCELLANEOUS 06012 90002 1 Option 002 Manual A 16 Figure A 13 Logic Symbols And Definitions Definitions High LOW more positive less positive indicator and Qualifier Symbols ox V PE it X e e DOD OR function polarity indicator shown outside logic symbol Any marked input or output
10. TO Figure 3 18 Auto Tracking Operation Positive and Negative Outputs 3 85 Resistor Values The method for determining the values of and Ry in Figure 3 17 is similar to that given in Paragraph 3 73 for auto series mode First choose the ratio of the slave output voltage to the master output voltage select a value for Ry and then determine the value for Ry by solving this equation VM Rx Ry 12 1 3 86 For example assume a two supply configuation in which the slave output is to vary from 0 to 50 volts while the master output varies from 0 to 30 voits if we select a value of 1k for Ry the equation becomes Rx 1288 1000 7 2 1 Ry 6200 m X 3 87 The same factors that govern the choice of auto series mode apply in auto tracking mode 3 88 Repeat the process for each slave with each slave referenced to the same master supply unlike auto series mode Note that the slave output voltage may be lower than equal to or higher than the master output voltage 3 89 For auto tracking operation with both positive and negative outputs as shown in Figure 3 18 the equation in Paragraph 3 85 is used to determine the values of Ry and Ry for the slave providing positive outputs and the equation in Paragraph 3 73 is used to determine the values of Ry and Ry for the slaves providing negative outputs 3 90 To maintain the temperature co
11. 5 18 5 100 Ammeter Adjustment 5 18 5 102 Voitmeter Adjustment 5 18 REPLACEABLE PARTS 6 1 INTRODUCTION 6 1 6 4 ORDERING INFORMATION 6 1 Vil COMPONENT LOCATION ILLUSTRATIONS AND CIRCUIT DIAGRAMS 7 1 APPENDIX A SYSTEM OPTION 002 A 1 APPENDIX B 100 Vac INPUT POWER OPTION 100 oso corn IS aa eph tn eso B 1 SECTION I GENERAL INFORMATION 1 1 DESCRIPTION 1 2 laboratory grade performance with the high efficiency of switching regulation techniques Autoranging allows the supply to provide at least 1000 watts output power over a wide range of output voltage and current combinations without the user having to select the proper output range The output is adjustable through the entire operating range of 0 to 60 volts and 0 to 50 amperes by 10 turn front panel controls 1 3 The supply is of the Constant Voltage Constant Cur rent CV CC type with green front panel LEDs to indicate whether the unit is operating in CV or CC mode Output voltage and current are continuously indicated on individual front panel meters secondary scale on the voltmeter in dicates Amperes Available within the maximum output power range secondary scale on the ammeter indicates Volts Available 1 4 Overvoitage protection OVP protects the user s load by quickly and automatically interrupting energy transfer if a preset trip voltage is exceeded screwdriver control on the front pan
12. control input clock R reset clear S set OLD SYMBOL NEW SYMBOL NOTES NEGATIVE GOING EDGE AT A OR POSITIVE GOING EDGE AT B TRIGGERS DEVICE BOTH RESET INPUTS MUST BE HIGH TO RESET DIVIDER Figure 7 7 Logic Symbols and Definitions 7 7 NOTES 1 Waveforms 1 2 3 and 4 are taken with 6012A operating at nominal line voltage 2 Waveforms 5 6 7 and 8 are taken with test setup shown in Figure 5 10 i e fuse ATF1 removed bias supplies operating at nominal line voltage and input bus voltage controlled by an external dc power supply 3 Except for waveforms 5 6 and 7 oscilloscope probe is grounded at 2015 case 4 For waveform 5 oscilloscope probe is grounded at source pin 5 For waveforms 6 and 7 oscilloscope probe is grounded at whichever pin drain or source is connected to the input bus For FET assembly to left of instrument as viewed from front upper FET assembly on schematic probe grounded at drain which is connected to side of input bus For FET assembly to right of instrument lower FET assembly on schematic probe is grounded at source which is connected to side of input bus WARNING Procedures described herein are performed with power supplied to the instrument and protective covers removed Such maintenance should be performed only by service trained personnel who are aware of the hazards involved for example fire and electrical shock Where procedure can be performed without
13. A current sink variable from 2 SOURCE to 0 mA produces an inversely proportional output voltage 0 5 from zero to fuil scale Many DACs include a sign change bit 0 that zero digital input to the DAC will produce a 0 volt output from the power supply and a maximum digital input to the DAC will produce a full scale output from the power sup Figure 3 7 Voltage Programming of Output Voltage 3 54 Scaled Voitage Programming of Output ply Note that the VOLTAGE control potentiometer can be Voltage The rear panel connections shown in Figure 3 8 used in place of the external resistor by connecting AB and A7 allow the output voltage to be varied by using an external in place of the 2 5k resistor connected between A7 and S voltage source of more than 5 volts to program the supply The ratio of the resistance values in the voltage divider must be selected so that the voltage at the center tap of the divider A7 varies from 0 to 5 volts as the programming voltage source CAUTION varies from zero to maximum 3 55 The total resistance of the voltage divider should if the DAC is tun ned off or the p rogram leads as small as practical without excessively loading the external open the output voltage will tend to rise above voltage source This minimizes degrading the programming rating The supply will not be damaged if this speed offset and drift specifications The voltage divider ap occurs but the OVP trip point s
14. MAX OPTIONAL SETS UPPER LIMIT PROGRAMMIN RESISTOR SETS LOWER 2 5K LiMIT Figure 3 10 Resistance Programming of Output Current 3 58 Voltage Programming of Output Current The rear panel connections shown in Figure 3 11 allow the output current to be varied by using an external voltage source to pro gram the supply The discussion in Paragraph 3 53 for cons tant voltage operation also applies for constant current opera tion 240 VOC TO Hs me VOLTAGE SOURCE 0 5 Figure 3 11 Voltage Programming of Output Current 3 59 Scaled Voltage Programming of Output Cur rent The rear panel connections shown in Figure 3 12 allow the output current to be varied by using an external voltage source of more than 5 volts to program the supply The discussion in Paragraphs 3 54 and 3 55 for constant voltage operation also applies for constant current operation 3240 VOC MAX TO VOLTAGE SOURCE 254 Figure 3 12 Scaled Voltage Programming of Output Current 3 60 Current Programming of Output Current The rear panel connections shown in Figure 3 13 allow the output current to be varied by using an external current sink to pro gram the supply See note following Paragraph 3 47 The discussion in Paragraph 3 56 for constant voltage operation also applies for constant current operation except that the CURRENT control can be used in place of the external resistor by connecting A4 to A3 in plac
15. ance with the manufacturer s instructions so that proper common mode rejection is attained 5 27 Figure 5 4 shows the test setup used to measure noise spikes Two coaxial cables must be used Impedance matching resistors must be included to eliminate standing waves and cable ringing and capacitors must be connected to block dc The length of the test leads outside the coaxial cable should be kept as short as possible The blocking capacitor and impedance matching resistor should be connected direct ly from the inner conductor of the cable to the power supply sensing terminal Notice that the shields of the two coaxial cables are not connected to the power supply 5 4 POWER SUPPLY DIFFERENTIAL OSCILLOSCOPE COAXIAL CABLES Figure 5 4 Constant Voltage Noise Spike Measurement Test Setup 5 28 Noise Spike Measurement Procedure To check the noise spikes proceed as follows a Connect test setup shown in Figure 5 4 b Tum CURRENT control fully clockwise Turn on power supply and adjust VOLTAGE control and load so that the front panel meters indicate 20 V and 50 A d Because the impedance matching resistors constitute a 2 10 1 attenuator the noise spikes observed on the oscilloscope should be less than 25 mV p p instead of 50 mV 5 29 The circuit of Figure 5 4 can also be used for the display of low frequency ripple Simply remove the four ter minating resistors and the blocking capacitors 5 30 Load Tra
16. 10 Note For CONTROL ISOLATOR BIAS voltages greater than 7 V a series resistor must be used to maintain the relay bias voltage within specified limits Enabling either relay is accomplished by bringing CV or CC enable line to CONTROL ISOLATOR BIAS common via a suitable driver maximum driver off state leakage 0 5 mA Table 1 Specifications Option 002 cont OUTPUT VOLTAGE MONITOR 0 to 5 V output indicates zero to maximum rated output voltage Accuracy 25 0 296 1 mV Output Impedance 8 3 kQ Temperature Coefficient 0 0196 C STATUS INDICATORS STATUS ISOLATOR BIAS input referred to STATUS ISOLATOR Voltage range 4 75 V to 16 V Current Drain 20 mA maximum Status Indicator outputs Open collector outputs Maximum output voltage logic high 16 V Logic low output 0 4 V maximum at 8 mA REMOTE CONTROL TRIP RESET INHIBIT CONTROL ISOLATOR BIAS input Voltage range 4 75 V to 16 V Remote control inputs REMOTE TRIP REMOTE RESET REMOTE INHIBIT OPTION CONTROL ISOLATOR BIAS 14475 TO On state logic low Minimum forward current required 1 6 isolator forward voltage Vg at 1 6 mA Ig 1 4 V typical 1 75 V maximum For CONTROL ISOLATOR BIAS voltage greater than 5 V an optional resistor may be added to reduce drive current Off state logic high maximum leakage current 100 REMOTE TRIP and REMOTE RESET timing
17. 33 758 ISA C MODEL 5012 A AUTORANGING SUPPLY in paragraph 5 38 j change 80 mV to 70 mV B 45 8 48 in paragraph 5 41 h change 23 mVdc to 20 mVdc Ba Table 5 3 under CV Circuit line 1 change 5 vote to 4 2 volts 8 48 Table 5 4 second line change 25 V to 16 V 8 43 paragraph 5 93 j and 5 93 1 change 22 V to 14 5 V 8 50 paragraph 5 93 and 5 93 1 change 240 V to 206 V 8 51 REPLACEABLE PARTS B 52 Section VI Manual Changes 8 53 For Option 100 change 8136 to 24 9 1 1 8 Part Number 0757 0311 Change R151 to 182 195 1 8 W HP Part Number 0698 4486 Change the Voltmeter and Ammeter to HP Part Numbers 1120 1396 and 1120 1397 Aiso add the fiont panel overlay HP Part Number 08012 00613 and the 90 105 V line label 7120 2087 HP Part Number B 4 54 APPENDIX E B 55 Appendix A Manual Change 56 Under Remote Programming for Constant Voltage Output in Table 1 and in paragraphs A 22 A 24 and A 30 Resistance Programming requires 0 to 20830 programming resistance Voltage Programming requires 0 to 4 17 V pro 202 gramming voltage and the Current Programming requires a 0 to 1 67 mA current sink to program the output from 0 50 E The Constant Current programming values for Option 100 the same as those shown in the Appendix A B 57 in Table A 1 and paragrephs A 22 A 24 A 26 30
18. 4 36 Down Programmer 4 5 4 39 Overvoltage Protection Circuit 4 5 4 42 AC Dropout Detector Siow Start 4 5 4 45 Bias Voltage Detector 4 5 MAINTENANCE 5 1 INTRODUCTION 5 1 5 3 TEST EQUIPMENT REQUIRED 5 1 5 5 PERFORMANCE TEST 5 2 5 7 Measurement Techniques 5 2 5 12 Constant Voltage Tests 5 2 5 42 Constant Current Tests 5 6 Section 5 52 5 57 5 60 5 63 5 64 5 67 5 69 5 71 5 73 5 75 5 77 5 81 5 83 5 86 5 90 Page Section TROUBLESHOOTING 5 7 Initial Troubleshooting Pro cedures iiis cov b av 5 7 Overall Trouble Isolation 5 10 REPAIR AND REPLACE 5 13 Outside Cover Removal 5 13 A2 Control Board Removal 5 14 A3 FET Boards And A4 Output Diode Board Removal 5 14 FET Board Disassembly 5 14 Output Diode Board Disassembly 5 15 A1 Main Board Removal 5 15 Relay K1 Removal 5 16 Component Access Through Bottom Chassis 5 16 Front Panel Removal 5 16 Replacement Parts 5 17 ADJUSTMENT AND CALI BRATION 5 17 Page 5 92 ip Limit Adjustment 5 18 5 94 Constant Voltage Offset Adjust eso cb nt 5 18 5 96 Constant Current Full Scale and Offset Adjustment 5 18 5 98 Constant Current Source
19. Trip voltage is adjustable from 2 to 52 V Minimum setting above output voltage to avoid false tripping is 1 5 V 196 Vout REMOTE PROGRAMMING Resistance Programming 0 to 20830 provides 0 to 50 V and 0 to 25000 provides 0 to 10 Accuracy CV 1 3mV CC 2 596 15 mA Voltage Programming 0 to 4 17 V provides 0 to 50 V and 0 to 5 V provides 0 to 10 Accuracy CV 0 3 3 mV 196 15 mA Current Programming 2 mA to 0 mA current sink pro vides 0 to 50 V with 20830 resistance and 0 to 10 A with 25000 resistance Accuracy CV 0 3 0 42 V accuracy of resistor CC 196 0 8 accuracy of resistor PROGRAMMING RESPONSE TIME Maximum time for output voltage to change from 0 V to 50 V or 50 V to 2 V and settle within the 60 mV band is Up Full Load 3 19 120 mS No Load 120 mS Down Full Load 3 10 400 mS No Load 1 08 o 100 200 300 400 500 600 TOO DOWN PROGRAMMING TIME m5 UP PROGRAMMING TIME 8 Your VOLTS METERS AND INDICATORS Continuously reading 60 V scale with secondary scale in dicating amperes available accuracy 396 of fuil scale MULTIPLE UNIT OPERATION Auto series Up to four units eight if center tapped to ground may be connected in series to increase total output voltage to 200 Vdc 400 Vdc if center tapped to ground while maintaining control from a single unit B 2 B 19 OPERATING INSTRUCTIONS B 20 Section Manual Changes B 21 In para
20. Troubleshooting measure ripple noise spikes and load HP 1740A transient response Sensitivity 1 nV Measure ac and dc voltages HP 3455A input impedance 10 minimum troubleshooting and calibration Accuracy 0 0296 6 digit Electronic Load Voltage Range 60V Power supply load Transistor Devices Current Range 50A Model DLP 130 50 2500 Power Range 1200W Open and short circuit switches RMS Voltmeter True RMS Reading Measure ripple HP 3400A Bandwidth 10 MHz Sensitivity 1 mV DC Power Supply Voltage Range 0 to 20V Troubleshooting slow HP 6024A Current Range 0 to 6A start procedure Variable at 30 Hz rate Current Measuring Able to pass 50 A de without Constant Current PARD test Tektronix Model P6303 Transformer saturating Probe AM503 Amplifier Bandwidth 20 Hz to 20 MHz must be used with Output voltage of at least 1 mV TM500 series power for 1 mA input module Value 50 mV 50A 1 mQ Accuracy 196 or better Isolation Transformer 4 minimum Troubleshooting Terminating Resistors Value 50 Q x 5 Non inductive Noise spike measurement four required Blocking Capacitors Value 0 01 uF 100 two Noise spike measurement required 5 1 Vary ac input for line regulation measurement troubleshooting Variable Voltage Autotransformer Voltage Range see Paragraph 2 15 4 kVA minimum Weston instrum
21. cap OT5uF 10 200V cap 100nF 20 10V cap ipF 5 35V cap 1 8nF 10 20V cap 470pF 5 300V cap 240pF 596 300V mica cap 100pF 596 300V mica cap 220pF 596 300V mica cap 3304F 100 1096 25V cap 10 35V cap 390pF 596 300V mica 0 47 80 2096 25V cer cap 750pF 596 300V mica cap 5000 20 100V cer cap 470 10 1kV cap 270pF 596 300V mica dio switching dio gen PRP connector 16 pin 100uH 5 10mH 5 J fet P chan D mode xstr NPN si xstr PNP si 2N5087 xstr PNP si xstr NPN si xstr NPN si res 10k 596 0 5W res 4 7k 596 0 25W cc res 3 3M 596 0 25W cc 6 4 Mfr Part No 15D105X0050A2 CACOAX7R104MO50 A 5CZ5U225X0050C5C CML CACO3Z5U 104Z050A 5030EM50RD224M 192P33392 192P68292 5033E525RD105M 150D154X9035A2 DYS HEW238M 192P 15392 150D107X0010R2 DYS 150D107X5035A2 DYS 1500185 9020 2 ECE A25V330L 150D105X9035A2 5OS3ES25RD47RZ 835 100 25U 502M FDH 6308 FDH 3369 0002811 SKC0221 2N5087 21297 1147 MJE182 EB1035 CB4725 CB3355 Ref Desig R8 R9 R10 R11 13 R12 30 55 124 R14 41 90 R15 R16 R17 R20 24 130 R21 23 131 R22 R26 R27 R28 81 83 R29 47 132 R31 45 60 R32 R33 53 62 91 112 R34 46 R35 R36 104 R37 133 134 R38 95 R39 64 R40 156 R42 R43 107 R44 R49 50 R52 148 154 R54 R56 69 73 75 77 Part No 0757 0413 0757 0480 0757 0344 0683 1005 0757 0280 0757 0461 0757 0398 0698
22. heatsink should not be connected for this test Observe ail precautions given in Paragraph 5 72 while handling FETs If Vas waveform 5 is correct with FETs removed then FETs were bad Gate to drain resistance lt 1MQ indicates bad Replace FETs in pairs on an assembly If waveform remains bad with FETs removed then driver circuits were bad Check 10 A3U1 U2 A3T1 A3CR3 A fault in the driver circuits will usually damage the FETs on that assembly Down Programmer 1 With VOLTAGE control one turn CW and OVP ADJUST fully CW output voltage should be 5V and anodes of 2 26 29 should be 2 4V Otherwise check cathodes of A2CR26 28 to determine which circuit is triggering down pro grammer 2 With anodes of A2CR26 29 2 4V and A2U19B inverting input pin 1 8 A2U19B non inverting input 0 6V A2U19B output should be 0V and 2012 and 401 bases should be Otherwise check A2U19B A2012 401 and associated components CV Circuit 1 Voltage from A7 to S should vary from 0 to 5 volts as VOLTAGE control is varied from minimum to maximum Other wise check VOLTAGE control and output of constant current source A201 2 Trace signal through A2U3 and A2U6B Amplifier output should be high when non inverting input is more positive than inverting input 3 With A2US non inverting input pin 2 positive 205 inverting input pin 3
23. other portions of the manual apply to both the standard unit and the Option 100 unit B 6 Suggestions for Using Appendix B B 7 The Option 100 changes are listed sequentially start ing with Section in the main body of the manual and working back through Section VII it is recommended that the user mark the necessary changes directly into the manual using Appendix B as a guide This will update the manual for Option 100 and eliminate the need for constant referrals back to pendix B B 8 Section Manual Changes B 9 in paragraph 1 2 change the output power from least 1000 W to at least 675 W and the operating range to from 0 to 50 V B 10 In paragraph 1 4 the Overvoltage Trip Point can be set between 2 V and 52 V B 11 Specifications Changes 8 12 Table 1 provides all specifications changes for Option 100 Specifications not listed in Table B 1 are the same as those in the main specifications Table 1 1 B 13 INSTALLATION B 14 Section 1 Manual Changes B 15 paragraph 2 16 the supply can be operated from a nominal 100 V source with the addition of Option 100 and with a derated output Add the following Nominal Line Voltage Maximum Voltage Range Input Current 100 V 90 105 24 A rms B 16 In paragraph 2 18 the power cord used for 120 V operation is also used for the 100 V operation of Option 100 B 17 In paragraph 2 24 line c change 22 V to 14 5 V B 18 Line Voltage Option i
24. see schematic diagram and Figure 7 A 48 The negative going pulse applied at REMOTE RESET is coupled through opto isolator U4 and resets the Trip Reset latch output high This releases the OV STATUS INHIBIT line and the Pulse Width Modulator A 49 The REMOTE RESET pulse will reset the power supply OVP circuit in the event that an overvoltage condition has shut down the supply This is accomplished through Q4 after the one second time delay of one shot U11A This delay A 8 allows the Down Programmer paragraphs 4 36 to 4 38 to lower the output from its overvoltage condition to zero before the supply can be reactivated m mmm em mos E 1 i i i i i i BIAS REMOTE RESET 4 p z i i i TRIP i i i i i i i Cs a a a a Figure A 7 Remote Control NOTE By observing the OVERVOLTAGE status dicator or power supply s output while applying a reset pulse to REMOTE RESET the user can determine the cause of the shutdown If the out put returns OVERVOLTAGE goes high mediately this indicates controller initiated shutdown If the output takes about one second to return this indicates that the output voltage had exceeded the OVP trip point f the OVP cir cuit trips continually check the load and or the trip point setting A 50 Altern
25. tion is critical use remote voltage sensing refer to Paragraph 3 37 Table 3 1 Copper Wire Current Carrying Capacity Wire Type note 1 20A 30A 40A 809 Stranded 1 12 1 10 0 1 8 2 14 2 12 2 12 80 Solid 1 10 1 48 1 46 2 14 2 12 2 10 105 Stranded 1 10 2 12 105 Solid 1 12 1 10 8 2 16 2 12 2 10 2 10 Notes 1 Maximum allowable conductor temperature based on 60 ambient temperature plus 20 or 45 temperature rise due to continuous dc current 2 Capacities based on assumption that and leads are twisted together to reduce noise pickup 3 Other wire combinations can also be used to provide the capacities listed in this table Note that increasing the number of conductors in a bundle does not increase the current carrying capacity by the number of conductors EG Two 10 wires bundled together provide only 1 89 times the current carrying capacity of one 10 wire 4 Current carrying capacity of aluminum wire is approximately 8496 of that listed for copper wire md t 3 8 The bus bars and terminal strip are protected by 3 12 The PARD specifications in Table 1 1 apply at the high impact plastic cover which is secured to the unit with power supply output terminals However noise spikes two 7 8 inch 86 32 screws Wires to the bus bars and terminal lt induced in the load leads at or near the load may affect the strip pass through slots in th
26. 1 has provisions for externally modulating the load Use of a 30 Hz square wave modulating signal provides a repetitive display that is easy to observe Follow the manufacturer s instructions for operating the electronic load to switch the load current by 1096 of the power supply s maximum output current capability at the selected output voltage e g between 9096 and 10096 be tween 3596 and 4596 etc OSCILLOSCOPE four UNLOADING TRANSIENT NOMINAL OUTPUT VOLTAGE LOADING 7 TRANSIENT le 16 7 mS EouT NOMINAL RE OUTPUT VOLTAGE 100mv 2 215 V OMINAL NOMINAL 0 25 OUTPUT VOLTAGE UNLOADING TRANSIENT LOADING TRANSIENT Figure 5 6 Load Transient Recovery Waveforms 5 34 Measurement Procedure To check load transient recovery time proceed as follows a Connect the test setup shown in Figure 5 5 b Set electronic load for external modulation and adjust load for maximum current to be used in test c Adjust square wave signal source for 30 Hz modulating signal Signal levels should be chosen in accordance with load manufacturer s requirements for varying load current by the desired amount d Set oscilloscope for internal sync and lock on either positive or negative load transient spike Set vertical input of oscilloscope for ac coupling so that small dc level changes will not cause display to shift 5 5 5 39 f A
27. 4 17 Constant Voltage CV Circuit 4 18 The Constant Voltage CV Circuit compares percentage of the output voltage to the CV Programming Voltage set by the VOLTAGE control Any difference is amplified to establish a control voltage as follows 4 19 Current from the Constant Current Source flows through VOLTAGE controi 582 to develop the CV Program ming Voltage at terminal A7 The level of this programming voltage is dependent on the setting of ASR2 Amplifier A2U3 compares a fraction of the 6012A output voltage at the Sense terminal to the programming voltage at A7 The out put of A2U3 is applied to a second comparison amplifier A2U6B This amplifier compares the output of A2U3 to a frac tion of the inboard Out which is the output voltage sensed at the inboard side of the output filter Use of two comparison amplifier loops provides increased stability for load variations 4 20 in normal CV mode the output of 2068 varies be tween 0 5 volts and 1 0 volts is at its most negative when the load is drawing little or no power from the instrument Progressively more positive voltages from A2U6B correspond to increased power demand by the load The out put from the CV Circuit is applied to diode A2CR18 4 21 Constant Current CC Circuit 4 22 Operation of the Constant Current CC Circuit is similar to the CV Circuit Output current from the 6012A develops a voltage across the Current Monitor Resistor A1R20
28. A FRONT 5 80 Figure 5 14 shows components on the main board that can be accessed through holes in the bottom chassis 5 81 Front Panel Removal 5 82 The front panel controls and indicators are wired to a printed circuit board mounted directly behind the front panel To remove the front panel proceed as follows a Remove top cover and disconnect front panel ribbon cable from J2 on control board b Remove snap out plastic trim strip that extends across top of unit above front panel c Remove two flat head screws in channel from which trim strip was removed one at each end Other screws may show through holes in the front chassis do not remove them d Turn unit bottom up and repeat step c for bottom of front panel e Turn unit top up and carefully pull front panel out from unit Remove two screws at top and three screws at bottom that secure front panel to bracket behind front panel g Disconnect ground wire from left side of chassis OO Figure 5 14 Component Access Through Bottom Chassis h Remove four screws that secure printed circuit board 5 89 adjustment potentiometers are located along the to bracket Be careful not to break connections to front panel top edge of the control board Figure 5 15shows the location potentiometers or meters of the adjustments as viewed from the left of the instrument i When replacing front panel remember to put ribbon cable through hole in right side of
29. AC Filter Assembly to the rear panel and carefully pull the assembly away from the rear panel b Prepare the power cord as shown in Figure 2 2 and insert the cord through the strain relief on the AC Filter Assembly c Connect the longer lead to the GND terminal connect one of the two shorter leads to the AC terminal hot side of the ac line and the other to the ACC terminal neutral or common side of the ac line d Position the cord so that the strain relief grips the outer jacket of the cord and tighten the strain relief e Replace the AC Filter Assembly f Connect the other end of the power cord to an ap propriate ac power source Figure 2 2 Power Cord Preparation NOTE Connections to the ac power line must be made in accordance with applicable electrical codes WARNING For proper protection by the instrument circuit breaker the wire connected to the AC terminal on the instrument must be connected to the AC s de of the line hot the wire connected to the ACC terminal must be connected to the ACC side of the line neutral or common To protect operating personnel the wire con nected to the GND terminal must be connected to earth ground no event shall this instrument be operated without an adequate ground connection Before applying power to the instrument check to see that the rear panel circuit breaker CB1 is in the NORMAL up position breaker may trip because of rough handling during
30. If there is reason to suspect the ac power lines to the 6012A may have high impedance perform the following check WARNING This check should be performed only by service trained personnel who are aware of the hazards involved for example fire and electrical shock Turn power supply off before making or breaking connections to power supply Hazardous voltages are present within the unit even when power Switch is turned off 2 3 Remove three screws that secure top cover to rear panel slide cover to rear and lift off b Monitor unregulated 5V pin K with respect to com mon pin E at test connector P2 on top edge of control board see Section VII 5V unregulated is less than 12 voits 6012A is not receiving adequate ac line input If 5V unregulated 2 12 volts proceed to step c c Connect variable load Table 5 1 lists recommended load to 6012A turn VOLTAGE and CURRENT controls to max imum fully CW and adjust load for 50A output current 6012A output voltage should be 22V if it is not proceed to calibration procedure in Section V If calibration is cor rect but unit does not provide 22V at 50A 6012A is not receiving adequate ac line input 2 25 LINE VOLTAGE OPTION CONVERSION 2 26 Line voltage conversion is accomplished by adjusting three components the two section line select switch S2 and jumpers W1 and W2 Figure 2 3 shows the locations of these components at the center rear section
31. K1 energized these signals are coupled to the CV and CC circuits in the main supply which in turn will program the supply s output from 0 to full scale a 31 if the programming lines become open circuited user s system becomes disconnected from J2 during current programming the Programming Protection circuit will bring the power supply output to zero 32 Remote Monitoring CUSTOMER SUPPLIED CONTROL ISOLATOR BIAS VOLTS amp A 33 The 002 Option board includes a voltage divider to provide a 0 to 5 V output corresponding to a 0 to full scale voltage output The voltage monitor output is available be tween pins J2 5 Voltage Monitor and J2 22 Sense Out M EM PRINS put impedance is 8 3 the monitoring device input im Figure A 6 Calculating Value of Series Dropping pedance should be at least 1 MQ to limit error to 1 basic Resistor accuracy 10 to limit error to 0 1 basic accuracy 29 To program voltage the current sink should con A 34 The signal from the mainframe is also nected from J2 21 CV CURRENT PROG to J2 20 15 V brought out through the 002 option board A 0 to 5 V output REG To program current the current sink should be con corresponds to a 0 to full scale current output The current nected from J2 2 CC CURRENT PROG to J2 20 monitor output is available between pins J2 3 Current
32. Monitor and J2 1 Outboard Sense Output impedance is 10kQ the monitoring device input impedance should be at least 1 to limit error to 1 basic accuracy 10 MQ to limit error to 0 1 basic accuracy A 35 some applications it may be desireable to install a noise suppression capacitor on these monitor outputs to lessen the effects of noise induced in the monitor leads The capacitors should be ceramic or tantalum type from 0 1 to The capacitor is installed directly across the monitor device input terminals A 36 Status Indicators A 37 Six optically isolated lines provide open collector digital outputs which indicate certain modes and conditions of power supply operation For proper operation of the opto isolators the user must supply the bias voltage STATUS ISOLATOR BIAS This voltage be 4 75 V to 16 depending upon the user s interface circuits Refer to the specification Table A 1 Connect the bias voltage be tween 12 37 STATUS ISOLATOR BIAS and J2 34 STATUS ISOLATOR COMMON The status indicator out puts are open collector referenced to STATUS ISOLATOR COMMON therefore it is necessary to connect a pull up resistor from each output to STATUS ISOLATOR BIAS When choosing the resistor viaue observe the current sink capabilites of these lines as described in the Specifications Table A 1 A 38 Because of the relatively slow and fall times of opto isolators Schmitt triggere
33. NG cover to instrument Lift back of cover slide cover to the rear and lift off Disconnect the power supply from the ac line and wait two minutes before performing any repair or 5 66 To remove bottom cover proceed as follows replacement procedures a Remove two pan head screws that secure cover to rear panel one at each side 5 64 Outside Cover Removal b Remove two flat head screws from front edge of bot tom cover c Remove four screws that secure two carrying straps to sides of instrument d Lift back of cover slide cover to rear and lift off It is not necessary to remove instrument feet 5 67 A2 Control Board Removal 5 68 The control board is held in place by two screws through the side panel To remove the control board proceed as follows a Remove top cover b Disconnect all wires from rear panel terminal block c Unplug cable from option card if installed d Unplug cable from front panel e On side panel remove two flat head screws that secure control board to right side panel f Grasp control board carefully and pull upward to unplug it from main board Do not use spacers between con trol board and side panel to pull control board g To remove U15 from control board first remove two screws that secure U15 case and heatsink to printed circuit board Then unsoider both U15 pins from board NOTE When replacing U15 you must spread a thin layer of heatsink compound between U15 case and heatsin
34. VOLTAGE Vy r s ZERO Mm re THEN RE PLUG RMER xc REMOVE SHORT FROM 2920 AND QUTPUT CHECK DROPOUT DETECTOR a TU CURE Sa OARA CIRCUIT 9 20 TROUBLESHOOTING TREE AT CLOSES AFTER 21560 TURN LINE SWITCH OFF RAISE VEXT SLOWLY TO 2 Figure 5 11 Slow Start Procedure 5 11 Table 5 3 Troubishooting After using the overall troubleshooting tree Figure 5 8 bias supplies troubleshooting tree Figure 5 9 and slow start pro cedure Figure 5 11 to isolate a fault to a particular circuit use the following guidelines with the schematic and standard troubleshooting techniques to locate the fault Relay Driver 1 DC voltage across A1C8 should be 130 to 175 volts 2 Approximately one second after ac power is applied dc voltage from pin 1 to pin 2 on A1U2 should be 1 2 to 1 7 volts dc voltage across ATVR1 should be lt 3 volts and A101 VBE should be 0 7Vdc A101 Vee should be lt 1 volt 3 With no load connected to output shorting pin 1 to pin 2 on A1U2 should cause relay to open Clock and PWM 1 Check for 320kHz 1 and 20kHz 2 clock signals 2 Check if PWM A2U9A 5 is inhibited by inputs to A2U10 3 Check on and off pulses 4 at A2P2 L and A2P2 10 FET Assemblies To isolate a fault to either the FETs or driver circuits remove all FETs and replace one FET on each assembly with a 3300 capacitor connected between the gate and source lead pins
35. and A6 for CV and the jumpers between A4 A3 and A2 for CC A 24 voltage source variable from 0 to 5 volts can be used to program the output voltage or current from 0 to full scale The load on the programming voltage source is less than 5 To program voltage the voltage source should be connected from J2 25 CV RES amp VOLT PROG to J2 22 Sense To program current the voltage source should be connected from J2 24 CC RES amp VOLT PROG to 42 1 out board sense The output can be up to volt positive with respect to outboard sense and sense be up to volt positive with respect to output Therefore a potential of up to 1 volt can exist between sense and outboard sense A discussion on programming with a voltage greater than 5 volts can be found in paragraphs 3 54 to 3 55 A 25 if the programming lines become open circuited user s system become disconnected from J2 during voltage programming the Programming Protection circuit will reduce the power supply output to zero A 26 Current Control Figure 5 A current sink variable from 0 to 2 mA can be used to program the output voltage or current from 0 to full scale The following paragraphs provide the necessary instructions for program ming with a current sink A 27 It is necessary to disable the front panel control pots and disconnect the supply s internal current sources from the programming voltage nodes This is accomplished at
36. and connect the and S ter minals directly to the and ends of its load 3 95 Auto Tracking with Remote Programming The output voltages of an auto tracking combination can be remotely programmed by programmming connections made to the master supply in addition the ratio of each slave s out put to the master s output can be remotely programmed by connecting a variable resistor to the slave in place of Ry The Output currents of the individual supplies can also be remotely programmed Observe ail precautions outlined in the remote programming paragraphs Simultaneous use of remote sens ing and remote programming is also possible during auto tracking operation 3 96 OUTPUT SIGNAL 3 97 amplified and buffered output signal from the current monitoring resistor is available between terminals A1 and 5 on the rear panel This signal be connected to a remote voltmeter to indicate the amount of output current The signal varies from 0 to 5 volts to indicate a zero to full scale 50 current output The terminal of the voltmeter should be connected to terminal A5 Output impedance at terminal 1 is 10k a load of 1 megohm will maintain 296 reading accuracy wrotection Circuit MANUAL CHANGES Model 6012A DC Power Supply Manual HP P N 06012 90001 ake all eorrections in the manual according to errata below then check the following for your power supply serial number and ent
37. bus voltage Repeat steps and until A2R20 is adjusted for 22V output with 240V bus voltage Output current should remain at during steps and m Turn off power supply and disconnect load shunt and autotransformer Disconnect DVM from input bus 5 94 Constant Voltage Offset Adjustment 5 95 The constant voltage offset adjustment is made with 509 40W load connected to the power supply Proceed as follows a Connect digital voltmeter DVM between A7 and 5 terminals b Turn power supply on and adjust VOLTAGE control for 10 mV reading on DVM c Disconnect DVM from A7 and S and connect DVM across output terminals d Adjust A2R21 for 120 mV 2mV on DVM Output voltage is 12x A7 voltage 5 96 Constant Current Full Scale and Offset Adjustment 5 97 Proceed as foilows a Connect a 1 shunt across output terminals b Turn on power supply c Connect digital voltmeter DVM between and 5 terminals d Adjust CURRENT control for 5V at e Disconnect DVM from A3 and A5 and connect DVM across shunt f Adjust A2R22 for 50 mV reading on DVM 50A output current g Disconnect DVM from shunt and reconnect DVM across and Ab h Adiust CURRENT control for 10 mV at A3 i Disconnect DVM from A3 and A5 and reconnect DVM across shunt j Adjust A2R23 for 1 mV reading on DVM 100 mA out put current output current is initially zero amperes there may be a few se
38. closer to front of instrument Be certain that jumper is firmly mated with terminal on main board Do not grip jumper insulation with pliers either grip jumper wire by hand or grip jumper terminal with pliers f Replace top cover and mark the instrument clearly with a tag or label indicating correct line voltage to be used OF INSTRUMENT aq 240 CAUTI 120 vac po 126 VAC 220 VAC CEREREM i ON 8 98 E H a 9 SM LT o S 4 IS y 220 240 Figure 2 3 Line Voltage Conversion Components 2 4 SECTION III OPERATING INSTRUCTIONS 3 1 INTRODUCTION 3 2 This section describes the operating controls and in dicators turn on checkout procedures and operating pro cedures and considerations for the Model 6012A Before the instrument is turned on all protective earth terminals extension cords auto transformers and devices connected to it should be connected to a protective earth ground Any interruption of the protective earth grounding will cause a potent al shock hazard that could result in personal injury 3 3 Only fuses with the required current rating and specified type should be used Do not use short circuited fuseholders or circuit breakers To do so could cause a shock or fire hazard 3 4 TURN ON CHECKOUT PROCEDURE 3 5 The following checkout procedure describes the use of the front p
39. current programming circuit Shorting them could cause improper programming of the power supply and possible damage to the user s load A 67 it may be desireable to install noise suppression capacitors on the bias supply outputs near the load circuits The capacitors should be ceramic or tantalum type approx imately O 14F to 1O amp uF A 68 MAINTENANCE A 69 The following paragraphs provide procedures and set ups to aid in checking and troubleshooting the 002 option board This information used in conjunction with the schematic drawing and the Operation section of this Appen dix will help in the isolation and repair of fauity circuits A 70 The adjustments on the option board set the voltage output and current limiting of the three Bias Supplies Although these potentiometers are set at the factory calibra tion procedures are provided for purposes of checking perfor mance and to aid in troubleshooting of these supplies A 71 When testing the option use of the test connector of paragraph A 17 will allow easier access to the J2 contacts A 72 Troubleshooting A 73 Before attempting to troubleshoot the 002 option board ensure that the fault is with the option itself and not with the main supply This can be accomplished by removing the top cover disconnecting ribbon connector P1 from the 2 Control Board and checking the operation of the main supply If the fault still exists proceed to the troubleshooting section paragraph 5 52
40. fan bracket and reconnect ground wire j Plastic trim strip across top of front panel should be replaced with channel in strip toward rear of instrument REAR OF POWER SUPPLY 5 83 Replacement Parts R20 Ip LiMIT e R2 CV OFFSET R22 FULL SCALE R23 OFFSET 2 5 84 Section VI of this manual contains a list of replace ment parts If the part to be replaced does not have a standard manufactuer s part number it is a special part and must be ob tained directly from Hewlett Packard After replacing a com ponent refer to Table 5 4 for adjustments that may be necessary R24 CONSTANT CURRENT SOURCE AdddnS uHiMOd 30 3015 LH9jH 5 85 Some components are mounted with spacers in sulators etc on leads Be certain to note location of mounting pieces before removing component and replace all pieces in proper location 5 86 ADJUSTMENT AND CALIBRATION 5 87 Adjustment and calibration may be required after per formance testing troubleshooting or repair and replacement Perform only those adjustments that affect the operation of 8430 AMMETER ADJUST the faulty circuit Table 5 4 lists symptoms indicating that ad RIS VOLTMETER ADJUST justment is necessary If two or more adjustments will be made they should be performed the order in which they are listed in Table 5 4 5 88 Unless otherwise stated ali adjustments are per formed with the power supply strapped as shown in Figure 3 3 The
41. in the main text Otherwise troubleshoot the option board as described in the following paragraphs A 74 Removal of the Option Board To facilitate troubleshooting of the 002 option the board can be removed from the power supply and electrically connected via the rib bon cable To remove the circuit board proceed as follows a Turn off power supply and disconnect line cord b Disconnect option board ribbon cable from J1 2 control board and remove control board as directed in Paragraph A 15 c Disconnect option 1 cable from J2 on rear panel remove two screws that secure option connector to rear panel remove two screws that secure option board to side panel and remove option board from instrument d Reinstall control board e With 6012A top cover still off place a piece of card board or other lightweight insulating material on top of 6012A and lay option board component side up on top of insulating material f Being cafeful not to damage ribbon cable by excessive stretching or flexing reconnect option board ribbon cable P1 to J1 on control board Red stripe on ribbon cable should be toward end of J1 marked with white dot toward front of instrument g Be careful that option board lies securely on insulating material and does not touch any part of the 6012A A 75 Isolating Faulty Circuit if it is apparent which function is not operating properly proceed to the appropriate paragraph if the problem i
42. is active low any unmarked input or output is active high dynamic indicator Any market input is edge triggered ie active during transition between states 5 any unmarked input is level sensitive Schmitt trigger indicates that hysteresis exists in device non logic indicator Any marked input or output does not carry logic information open collector or open emitter output monostabie one shot multivibrator indicates pulse width usually determined by external RC network gate input a number following G indicates which inputs are gated control input clock reset clear set OLD SYMBOL NEW SYMBOL NOTES Output requires external components to achieve logic state A positive going transition at A or a negative going transition at B triggers the one shot External timing components connect to non logic inputs Output changes state rapidly regardless of input rate of change 17 15V REG 5V REG CUR ADJ 45V REG V ADJ 15V REG CUR AD CUR ADJ 45V REG V ADJ w gt io V ADJ Figure A 14 Option 002 Board Component Location A 18 SCHEMATIC NOTES ALL RESISTORS ARE IN OHMS 2 5 L 4W UNLESS OTHERWISE INDICATED 2 ALL CAPACITORS ARE MICROFARADS UNLESS OTHERWISE INOICATED WHITE SILKSCREENED DOTS ON BOARDS INDICATE ONE OF THE FOLLOWING PIN 1 OF EXCEPT FOR UIS SEE NOTE 4 B POSITIVE END OF POLARIZED CAPA
43. loads b Connect DVM between J2 20 15 V and J2 7 power supply common Turn on supply and adjust R48 until DVM reads 15 V 75 Turn off power supply and disconnect DVM Connect 500 5 watt resistor between J2 20 and J2 7 Connect DVM across this resistor on supply and adjust R47 until DVM reads 6 25 V 0 15 This limits the output current to 125 Turn off supply and disconnect DVM and resistor C1 3 13 C2 11 C4 6 C5 7 14 18 31 C12 16 17 C15 C19 C20 30 C21 C22 23 C25 C26 C27 C28 C29 CR1 2 3 16 17 4 9 10 11 12 14 15 CR5 8 13 18 19 J2 K1 2 Q1 4 Q5 7 R1 3 R4 6 87 9 13 21 10 12 11 14 38 R15 18 16 17 19 39 R20 22 42 R23 53 R24 52 R25 R26 R27 R28 37 R29 33 R30 R31 R32 R34 R35 R36 R40 0160 3070 0160 4822 0160 2639 0160 4722 0140 0210 0160 4832 0180 0405 0160 2012 0160 0157 0180 2825 0160 3968 0180 0533 0160 4557 0180 2407 0160 4830 0160 4833 0180 0100 1901 0327 1901 0033 1901 0050 1251 6075 0490 1277 1854 0823 1853 0234 0683 2015 0686 1525 0683 4715 0683 3355 0757 0441 0683 4315 0698 6631 0683 1055 0813 0001 0683 1035 0757 0427 0683 4725 0683 3335 0698 6343 0698 4158 0757 0449 0683 1535 0683 2715 0683 2745 0757 0317 0683 1615 0683 2725 0757 0400 0757 0483 e AQ m AS oU AG c c M
44. operator having to select the proper output range 4 3 SIMPLIFIED SCHEMATIC DESCRIPTION 4 4 The basic operating concepts of the 6012 are shown on the simplified schematic Figure 4 2 and described in the following paragraphs Detailed descriptions are provided only for those individual circuits and components whose operation may not be obvious to the user The circuit names and layout of the simplified schematic are the same as used on the com plete schematic in Section Vil however some items such as the Display Circuits are left off the simplified schematic for clarity The heavy lines represent the input rails and output rails Positive logic conventions are used signals with a bar are low when true E g ON INHIBIT goes low to inhibit on pulses high to enable on pulses MAX Pour 40V 5 1000W 25A 5 A TYPICAL 4000W SUPPLY 1000W SUPPLY B DUAL RANGE 4 5 Basic Concept 4 6 The 6012A is a flyback type switching power supply so called from the flyback technique of generating high voltage in television receivers in the 6012A energy is stored in the magnetic field surrounding a transformer while current flows in the primary and this energy is transferred to the secondary circuit when current flow in the primary is turned off Current flow in the primary is controlled by FET switches which are turned on and off at a 20kHz rate by a pulse width modulator Regulation is accomplished by
45. performance tests directly to the power sup 5 2 ply sensing terminals S S For best accuracy the sens ing 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 This is particularly important when measuring the regulation of the power supply 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 sup ply impedance typically 1 milliohm at dc thus invalidating the measurement MONITORING TERMINALS TO NEGATIVE TO POSITIVE TERMINAL OF TERMINAL OF POWER SUPPLY x POWER SUPPLY LOAD TERMINALS Figure 5 1 Current Monitoring Resistor Connections 5 14 To avoid mutual coupling effects connect each monitoring device to the sensing terminals by a separate pair of leads Use coaxial cable or shielded two wire cables to avoid pickup on the measuring leads Connect the load across the output terminals as close to the supply as possible When measuring the constant voltage performance specifications the CURRENT control should be set at least 2 above the Output current the load will draw since the onset of constant current operation could cause a drop in output voltage in creased ripple and other performance changes not properly ascribed to the c
46. performed only by service trained personnel wha are aware of the hazards involved for example fire and electrical shock Energize the power sup ply through an isolation transformer to lessen the danger of electrical shock from contacting an energized circuit while contacting the instrument frame or other earth ground The isolation transformer must have a power rating of at least 4 kVA The safest practice while working on energized circuits is to disconnect power make or change test connections and then reapply power A red LED 051 on the main board lights to in dicate that the input bus is energized DST is cluded in the event the relay contacts are stuck or welded closed this case the input bus re mains energized even when the LINE switch is turned off 057 goes out when the input bus voltage drops below approximately 80 Vdc Some components are at ac line potential even with the LINE switch off 5 52 5 53 Before attempting to troubleshoot this instrument ensure that the fault is with the instrument itself and not with an associated circuit The performance test enables this to be determined without having to remove the covers from the supply 5 54 The most important aspect of troubleshooting is the formulation of a logical approach to locating the source of trouble A good understanding of the principles of operation is particularly helpful and it is recommended that Section IV of this manual be r
47. the rear panel terminal strip by disconnecting the jumpers between 8 A7 and A6 for CV and the jumpers between A4 A3 and A2 for CC A 28 Current programming is enabled by relays K2 for CV and or K1 for CC which are powered from the CON TROL ISOLATOR BIAS connected to J2 10 Maintaining a low logic level CONTROL ISOLATOR BIAS supply common at one or both of the CURRENT PROG ENABLE inputs J2 12 CV and J2 11 CC closes the appropriate relay CAUTION Although CONTROL ISOLATOR BIAS can be 4 75 V to 16 V a supply voltage of more than 7 V may damage the relays Therefore if CON TROL ISOLATOR BIAS exceeds 7 V it is necessary to a resistor in series with each of the relay enable lines Figure A 6 provides a graph and formulas for calculating the proper series resistance value based on the CONTROL ISOLATOR BIAS being used Be certain to ac count for the resistor tolerance and CONTROL ISOLATOR BIAS power supply tolerance The formulas and graph Figure 6 account for relay tolerance driver gate voltage drop should be subtracted from the CONTROL ISOLATOR BIAS before using formulas and graph Figure 6 AZ CONTROL BOARD 002 OPTION BOARD pu cere cres CC 1 1 MONITOR AMPLIFIER CONSTANT cc PROGRAMMING RESISTOR O 2 5K CC PROG VOLTAGE _ E sense SENSE CV CIRCUIT EE RM CV PROG VOLTAGE
48. transit If the breaker trips while power is on or if the breaker is found to be tripped at any time for unknown reasons refer to troubleshooting procedures in Section V 2 20 Rack Mounting 2 21 This instrument can be rack mounted in a standard 19 inch rack panel or enclosure All rack mounting accessories for this unit are listed in the ACCESSORIES paragraph in Sec tion Complete installation instructions are included with each rack mounting kit 2 22 AC LINE IMPEDANCE CHECK 2 23 The 6012 is designed for proper operation with line impedance typically found in ac power lines However if the 6012A is connected to an ac power line having high pedance combined with line voltage near the minimum specified value e g 104 Vac for nominal 120 Vac some components may overheat if the unit is asked to provide full rated output power Such a situation might occur if the 6012A is connected to ac power an extended distance from the main ac distribution terminals and or if the ac power wires from the main ac distribution terminals are of relatively small gauge 2 24 Measurement of ac line voltage at the 6012A input terminals typically is not a reliable indication of the actual ac line voltage because of the peak clipping effect of the power supply and the averaging effect of the voltmeter Symptoms of excessive line impedance may include erratic or no output from the 6012A and or inability of the 6012A to provide full output power
49. zero output Otherwise there will be a fixed error that will be relatively large compared to the zero output desired The DAC must have a very low temperature coefficient to avoid drifting Most DACSs have a temperature compensating resistor through which they sink current but this com pensation is not effective when used with an ex ternal resistor such as that used when current programming the power supply Both of these error possibilities mis calibration and temperature drift are most pronounced when programming zero or near zero output volts or amperes For these reasons and for reasons given in the current programming paragraphs it is recom mended that current programming of either out put voltage or output current be accomplished via System Option 002 3 48 Connecting a supply for remote programming of out put voltage or current disables the corresponding front panel controis 3 49 The following paragraphs discuss in greater detail the methods of remotely programming the output voltage or cur rent using either a resistance voltage or current input Whichever method is used the wires connecting the program ming terminals of the supply to the remote programming device must be shielded to reduce noise pickup The outer shield of the cable should not be used as a conductor and should be connected to ground at one end only For clarity Figures 3 6 through 3 13 do not show shielded cable 3 50 Although the follo
50. 04713 01295 04713 27014 31585 27014 Mfr Part No CB5125 CB1025 CB5094 C4 1 1 8 TO 267R F CB2265 CB2025 CB3335 C4 1 8 TO 1782 F C4 1 8 TO 5623 F CB3925 CMF 55 1 T 1 C4 1 8 TO 909R F C4 1 8 TO 562R F C4 1 8 TO 6302 F C4 1 8 TO 2151 F C4 1 8 TO 750R F CB2715 C4 1 8 TO 7501 F C4 1 8 TO 402R F C4 1 8 TO 1501 F CMF 55 1 T 1 CMF 55 1 T 2 C4 1 8 TO 301R F C4 1 8 TO 3482 F CB2235 55 1 1 C4 1 8 TO 357R F C4 1 8 TO 249R F C4 1 8 TO 107R F CMF 55 1 1 2 CMF 55 1 T 1 C4 1 8 TO 619R F C4 1 8 TO 432R F C4 1 8 TO 143R F C4 1 8 TO 2003 F LM358N SC73140P LM301AN LM324N LM311N SN74LS33N SN74LS38N SN74LS574N SN74LS11N SN74LS293N SN74LS221N MLM339P LM309K CA3081E LM307N Table 6 4 Replacement Parts continued Mfr Part No Ref HP Mfr Desig Part No TQ Description 1902 0057 dio znr 6 49V 596 02730821 1902 0575 dio znr 6 5V 2 5211594 1902 0766 dio znr 18 2V 5 230016 257 1902 3092 dio znr 4 99V 2 027308182 1902 0777 dio znr 6 2 5 14825 1902 3002 dio znr 2 37V 5 5210939 2 0960 0586 resonator ceramic FET Assembly 2 Units 0160 4569 cap 0 014F 1096 800Vdc 715P10398LD3 0180 0374 cap 10uF 1096 20V 150D106X902082 DYS 0180 0155 cap 2 2uF 2096 20V 150D225X0020A2 1901 1087 1 dio pwr rect 600V 3A MR856 1901 0050 3 dio switching FDH 6308 9100 1618 1 coil 5 64H 10 5080 192
51. 1 2 paragraph 1 18 add the follow ing statement under Front handle kit for 5 1 4 inch high cabinets will be shipped with instrument if ordered Opton 907 On page 5 11 Figure 5 11 add the following section to the flow chart where the first decision box appearing below is the same as the one appearing in the manual NGS WAVEFORMS ON BOTH FET ASSEMBLIES OK 4 NOTE 2 CHECK FOR ACROSS RASSE Vext SLOWLY TO 20V CHECK _ CHECK A1C2 AND VR2 ERRATA In Section II Installation page 2 2 paragraph 2 18 should read Input power isk connected to the instrument via the AC Filter Assembly on the rear panel The power cord must be a three conductor cord rated for at least 85 degrees For 120 tion each conductor must be AWG 12 3 312 or larger For 220 V 240 V operation each conductor must be AWG 14 2 082 or larger Larger wire sizes may be required to prevent excessive voltage drop in the AC input Em CHANGE 8 This change also applies to the following serial numbers 21214 00327 21474 00684 21214 00334 21474 00687 2136 00600 2136 00609 12136A 00612 21 00688 00692 2136A 00615 00617 21474 00695 2147A 00699 2147A 00700 00703 2136A 00615 2147A 00705 2136 00563 2147A 00707 2136 00670 00672 2147A 00708 2136A 00676 00679 2147A 00170 00717 In the replace
52. 2K 1 1 8W HP P N 0751 0h59 TQ 1 and R182 10K 1 1 8W HP P N 0751 0hh2 TQ 2 Make these ad ditions on page 1 4 figure 7 3 Control Board 2 Component location as follows R180 R181 R182 and C60 are added between resistors R98 and R92 the finished change should display the components the follow ing order R98 R180 R181 R182 C60 and R92 Add R180 R181 R182 and C60 to the Schematic Diagram Figure 7 9 shown below These components are added on the A2 Board in the Dropout Detector Slow Start Circuit 5V 5V Model 6012A Page h CHANGE 18 cont On page 6 5 change R81 to 20K 1 1 8W HP P N 0757 0449 TQ 1 and change the TQ of R28 to 2 On page 6 6 change R119 to 21 5 1 1 8W HP P N 0751 0199 TQ 1 CHANGE 19 In the Replacement Parts list page 6 3 add C29 0hTuf 250Vac TQ 1 HP P N 0160 4323 On Figure 7 9 Schematic Diagram near the LINE SWITCH ASSEMBLY sketch C29 between points P2 and r2 page 7 3 Figure 7 2 Main Board A1 Component Location capacitor C29 is installed from standoff Rl to standoff R3 ERRATA in the replaceable parts list 6 3 change and to HP P N 1901 1154 qty 2 CHANGE 20 In the replaceable parts list page 6 9 un der Chassis Mechanical change front panel to HP P N 06012 00016 Change Bracket Meter to HP P N 06012 00017 Qty 1 page 6 7 under Front Panel Assembly change meter volts to HP P N 1120 1902 a
53. 5 9 MAS SUPPLIES CONNECT OMM TO OUTPUT TERMINALS CHECK VOLTMETER AND ASSOCIATED CIRCUITS CHECK CLOCK AND PWM CHECK Cv CIRCUIT CHECK FRONT PANEL CABLE COMPONENTS CHECK FET ASSEMARIES CHECK DOWN PROGRAMMER CAPACITORS CHARGE UP TURN OVP ADJUST FULLY CW TURN LINE SWITCH OFF FOR LEAST TWO SECONOS AND BACK ON ANO CONNECTOR CURRENT LIGHT AND ASSOCIATED i i CHECK FRONT PANEL CALE COMPONENTS GO TD FIGURE 5 14 SLOW START REMOVE OUTPUT DIQOE ASSEMBLY CHECK OVP CIRCUIT CHEX SHORTS ACROSS OUTPUT RIG Ctt 212 C21 CRIO CRU CRIZ 14 FALLEN WIRES BROKEN OUTPUT CONNECTORS AND SUPPORTS CHECK DOWN PROGRAMMER Qv CIRCUIT OUTPUT GIGDE SHORTED CHECK DROPOUT DETECTOR SLOW START CIRCUIT REPLACE DIODE CHECK FRONT PANEL CABLE AND CONNECTOR UNREGULA TED LIGHT AND ASSOCIATEC COMPONENTS 90 70 PERFORMANCE TEST Figure 5 8 Overall Troubleshooting Tree 5 8 NO GO TO TABLE 5 2 BIAS FUSE M VOLTAGES YES REMOVE 2 CONTROL BOARD AND FUSE AIFS CONNECT 1501 TRANSFORMER VARIABLE AUTOTRANSFORMER AND AMMETER TO GOIZA AS SHOWN IN FIGURE 5 40 FIGURE 7 1 SHOWS LOCATION OF 45 AND J6 DO NOT MAKE ANY CONNECTION TO AC OR ACC ON 5012A DO NOT CONNECT LOAD 6042A LINE SWITCH SHOULD BE OFF SLOWLY INCREASE AUTOTRANSFORM
54. 50Vac cap 2600uF 10 50 75Vdc cap 2200pF 2036 250Vac cap 20004 10 100 28Vdc 220uF 50 1096 50V dio IN5406 dio pwr rect 600V 3A dio pwr rect 400V 10A dio switching dio pwrrect 200V 1A LED visible fuse 75A 250V conn pc edge relay DPST choke input choke ass y consists of core ferrite wire snubber choke ass y consists of core magnetic choke output choke ass y consists of core ferrite choke RF choke 154H 10 xstr NPN si xstr NPN si res 30 5 10W ww res 200 5 10w ww res 3000 596 0 5W cc res 5k 55 10W ww res 2 70 i596 0 5W cc res 1 3k 5 3W ww res 160k 596 0 5W cc res 100 596 0 5W cc res 20k 596 0 25W cc res 470 5 0 5W cc res 6k x 596 SW ww res monitor 3 7mQ res 14 70 1 0 125 Wf sw si 2 DPDT xfmr current lim xtmr pwr xfmr bias dio fw brdg 600V 35A opto isolator dio fw brdg 400V 1A 6 3 Mfr Code 28480 C0633 28480 31918 CO633 00853 CO633 56289 54473 14936 04713 04713 07263 03508 28480 71400 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 27014 04713 91637 01686 01121 91637 01121 01686 01121 01121 01121 01121 91637 28480 16299 82389 28480 28480 28480 04713 04713 14936 PME271Y510 EN12 35N22 250 PME271Y515 101262T075AJ2A PME271Y422 TYPE 680 D44591 DFP ECE A50V220L 5406 MR856 SR1358 9 FDH6308 A14B AGC 3 4 ST48090A 551147 85 10 110 78 015 RS 10 EB27G5 2 73
55. 6 If present check 2011 A2U18 A2R149 28150 A2R158 A2R159 A2R24 A2R29 A2VR6 2 46 Check for presence of 12V Unreg 19V to 31V pin 2 4f absent check 1 15 if present check 208 2017 A2R142 A2R143 A2R156 A2R157 2 45 bias voltages measured at control board test fingers P2 with respect to bias common at pin E or at 2015 case Table 7 2 lists semiconductor components operating on each bias supply s NBL REMOVE FUSE CONNECT TEST SETUP IN FIGURE 5 0 WITH RAISE SLOWLY TO VBUS Vext REINSTALL FET ASSEMBLIES AUTOTRANSFORMER OUTPUT i V j 40V LINE SWITCH ON VOLTAGE ANI CORE TROLS 80 CON CW SUPPLY CURRENT LIMIT SHOULD BE BETWEEN YES NO OSA AND 4 CHECK THAT 152 W1 AND W2 ARE SET PROPERLY FOR THE NOMINAL LINE VOLTAGE MONITOR BUS VOLTAGE WITH DVM CONNECTED BETWEEN ENDS OF RGI AND RSC SET V TO 9 REYER TOWARD FRONT OF MAIN BOARD SEE FIGURE 7 11 gT E CONNECTIONS CLEAN AIKI CONTACTS K Ad RAISE Vegy SLOWLY TO CHECK 40 CHECK FETS SNUBBER RAISE SLOWLY TO COMPONENTS AND AICR CHECK SET YO REMOVE YES BOTH FET ASSEMALIES RAGE SLOWLY TO 22 SET VExT TO REVERSE SET vex 10 Vext CONNECTIONS RAISE VEXT SLOWLY 0 42 10 CHECK 5 AND DRIVER FET ASSEN CHECK COMPONENTS IN IN 4 CIRCUITS PUT SECTION
56. 6 2 FET dual TO3 1854 0585 1 xstr NPN si MJE182 0811 1906 1 res 1500 5 10W pw RS 10 0811 1065 1 res 1500 5 10W pw NT 10 78 0698 3609 4 res 220 596 2W Fp 42 0683 0275 1 res 2 72 5 0 25W fc 0275 0683 1815 1 res 1800 5 0 25W fc CB1815 0683 2745 1 res 270k 596 0 25W fc CB2745 0683 1505 1 res 150 596 0 25W fc CCB1505 0683 0335 1 res 3 30 5 0 25W fc CB33G5 0683 8205 2 res 820 5 0 25W fc CB8205 0698 3547 3 res 10 596 0 5W cc EB3547 06012 80091 1 xfmr pulse 3103 0081 1 Sw therm 2455R 87 247 1820 1050 2 IC dual 2 IN NOR tti SN75454BP 1902 3092 1 027308182 dio znr 4 99V 2 Output Diode Board 0160 4569 1901 0887 715P10398LD3 cap O1u F 1096 800Vdc dio pwr rect 50A choke assy consists of core ferrite 9170 0707 gt IN 06012 80003 wire snubber 1854 0755 xstr NPN si 2N6254 0812 0019 res 330 596 3W pw CW 2B 39 0683 1025 res 1k 596 25W fc CB1025 0811 1068 res 500 596 10W pw NT10 78 3103 0082 Sw therm 2450 87 246 Front Panel Assembly 1990 0521 LED Green 1990 0517 LED Red 1120 1392 Meter Voits 1120 1393 Meter Amperes 0683 2015 res 2000 596 0 25W fc CB2015 2100 3831 res var 2 7 5 0 5W 83A1D 1324 BA0380 2100 3252 res var 5k 10 E2A502 Should be replaced in pairs 6 7 Table 6 4 Replacement Parts continued Ref HP Desig Part No Descriptio
57. 6343 0698 4158 2100 3273 2100 3353 2100 3351 0698 7880 0698 6335 0757 0451 0757 0438 0757 0452 0757 0424 0757 0465 0757 0449 0757 0442 0683 1045 0757 0467 0683 1065 0683 2035 0698 4484 0698 3455 0683 1055 0698 5092 0698 6631 0683 2225 0683 5105 0757 0283 0757 0346 0683 4715 0698 4444 0683 2015 0683 5115 0757 0446 0757 0455 0683 1015 0698 3498 0757 0199 0683 0335 wa No No 2 mh 9 9 02 4 G3 gt 5 2 1 2 3 2 2 2 1 2 1 2 3 1 o2 o Table 6 4 Replacement Parts continued Description res 3929 196 0 125W f res 432k 1 0 125W f res 1M 196 0 25W f res 100 596 0 25W fc res 1k 1 0 125W f res 68 1k 196 0 125W f res 750 1 0 125W res 9k 0 1 0 125W f res 100k 0 196 0 125W f res trmr 2k 1096 res trmr 20k 1096 res trmr 500 1096 res 28 7k 196 0 125W f res 9000 196 0 125W f res 24 3k 196 0 125W f res 5 11k 196 0 125W f res 27 4k 196 0 125W f res 1 1k 196 0 125W f res 100k 196 0 125W f res 20k 196 0 125W res 10k 19 0 125W f res 100k 5 0 25W fc res 121k 1 0 125W f res 10M 5 0 25W fc res 20k 5 0 25W fc res 19 1k 196 0 125W f res 261k 196 0 125W f res 1M 596 0 25W fc res 160k 196 0 125W f res 2 5k 0 196 0 125W f res 10k 596 0 25W fc res 340k 1 0 125W f res 2 2k 5 0 25W fc res 510 5 0 25W fc res 2k 196 0 125W f res 100 196 0 125W f res 4700 596 0 25W fc res 4 87 1 0 125W f res 2000 5
58. 96 0 25W fc res 5109 5 0 25W fc res 15k 196 0 125W f res 36 5k 196 0 125W f res 1009 5 0 25W fc res 8 66k 1 0 125W f res 21 5k 1 0 125W f res 3 30 596 0 25W fc 6 5 Mfr Part No C4 1 8 TO 61R9 CMF 55 1 T 1 MF52C 1 CB1005 C4 1 8 TO 1001 F C4 1 8 TO 6812 F CRB14 55 1 9 CMF 55 1 T 9 72XR2K 63X203T623 63X501T623 C4 1 8 TO 2872 F C4 1 8 TO 900R F C4 1 8 TO 2432 F C4 1 8 TO 511R F C4 1 8 TO 2742 F C4 1 8 TO 1101 F C4 1 8 TO 1003 F CCMF 55 1 T 1 C4 1 8 TO 1002 F CB1045 C4 1 8 TO 1213 F CB1065 CB2035 C4 1 8 TO 1912 F C4 1 8 TO 2613 F CB1055 C4 1 8 TO 1603 F 55 1035 4 CB2225 R 25J C4 1 8 TO 2001 F CRB25 CB4715 C4 1 8 TO 487R F CB2015 5115 C4 1 8 TO 1502 F C4 1 8 TO 3562 F CB1015 C4 1 8 TO 866R F C4 1 8 TO 2151 F 0335 Part No R87 109 0683 5125 R92 100 0683 1025 R93 0698 5094 R96 116 117 0698 0085 0683 2265 0683 2025 0683 3335 0698 3136 0757 0483 0683 3925 0698 3151 0757 0422 0757 0200 0698 5152 0698 0084 0757 0420 0683 2715 0757 0440 0698 3558 0757 0427 0757 0410 0698 6889 0757 0273 0757 0123 0683 2235 0698 6938 0757 0473 0757 0290 0757 0436 0698 3225 0757 0472 0360 2009 1826 0346 1826 0493 1820 0477 1826 0161 1826 0065 1820 1272 1820 1209 1820 1112 1820 1203 1820 1443 1820 1437 1826 0138 1820 0430 1858 0023 1820 0493 5 IN
59. A 2 14 INSTALLATION A 15 The 002 option board can be installed in a 6012A power supply by the user Proceed as follows Turn off power supply and disconnect line cord b Remove three screws that secure top cover to instru ment Slide cover to rear and lift off c Disconnect front panel cable from J2 on 2 control board remove two screws that secure control board to side panel and remove controi board from 6012A d Remove and save two screws that secure cover over J2 connector hole in rear panel Discard J2 connector hole cover e Option board is installed on far right side of instrument as viewed from front Three tabs on bottom of option board fit into three slots in bottom chassis Secure op tion board to side panel with two screws provided f Using two screws removed in step d secure option con nector J2 to rear panel g Reinstall control board in unit and secure to side panel Reconnect front panel cable to J2 on control board h Connect 16 pin ribbon connector P1 from option board to connector J1 on control board Red stripe on ribbon cable should be toward end of J1 marked with white dot toward front of instrument i Replace top cover j Read operation section of this appendix before turning on instrument and checking the 002 Option No preliminary adjustments are required A 16 Connector Assembly Procedure A 17 The following instructions describe assembly of the mating connector provided
60. ARI 83 AIUI TE AICRI CR2 CBI SI YES CURRENT DRAIN lt 250m AND WAVEFORMS ON BOTH NEUE ESTER ff SET 108 SLOWLY IN FET ASSEMBLIES DK C55 Mea 1 x M AUTOTRANSFORMER AUTOTRANSFORMER OUTPUT CURRENT INTHIS AND IN FOL CM SET VEXT TO REMOVE LOWING STEPS TURN AUTO QUTPUT DIODE ASSEMBLY M ros TRANSFORMER BACK 70 RAISE Vext SLOWLY TO ZERO IF QUTPUT CURRENT 20v Ana EXCEEDS 750mA SET TO 8 RAISE CHECK OUTPUT DIODE ASCRI AUTO POWER SUPPLY CURRENT A4R ASCE MCH CT2 TRANSFORMER 60 FIGURE 5 9 BIAS ATCRIO RIZ AIRIS amp 4 SUPPLIES SHORTS ACROSS OUTPUT CHECK DOWN PROGRAMMER CHECK OUTPUT DIODE 44CM ASLE AIT2 Lo wien Ri 8 14 20 RED AND BLACK OF NOMINA CHECK RELAY DRIVER T WIPES EROA BOARD 70 BUS BARS SET AUTOTRANSEORMER GUY PUT YO NOMINAL ip SENSE VOLTAGE WAVEFORM OK gt i 581 CHECK AITZ AZCRIT 22859 2963 864 YES CHECK BIAS VOLTAGE LIST D TABLE 5 2 MOMENTARILY SHORT 70 GETHER PINS AND2 ON A2R2O fip LIMIT ADJUST CHECK COMPONENTS LISTED VOLTAGES iN TABLE 5 2 THEN GO 79 NOTES FIGURE 5 9 BIAS SUPPLIES SENSE WAVE FORM PRACTICALLY t NUMBERS N BRACKETS 2 REPRESENT WAVEFORMS YES 2 ASSEMBLIES MAY BE OPERATED GN EXTENDER BOARDS BUS
61. CC Mode A 78 Troubleshooting Status Indicators The test set up shown in Figure A 12 can be used to check each of the six status indicators This set up however will temporarily defeat the isolation of the status lines Before attempting to troubleshoot a status indicator check for 5 Vat TP1 5V INT This voltage must be present for proper operation of the opto isolators TO OUTPUT OF STATUS INDICATOR BEING TESTED Figure 12 Troubelshooting Status indicators 79 CV proceed as follows a Using test set up connect top end of 2 K Q resistor to J2 36 b Set CURRENT control one turn clockwise CW and VOLTAGE control also one turn CW Turn unit on DVM should read 4 V Turn unit off Short circuit the supply s output Turn unit on DVM should read about 5 V 80 To check CC MODE proceed as follows a Using test set up connect top end of 2 kQ resistor to J2 35 A 12 Set CURRENT and VOLTAGE controls one turn CW Turn unit on DVM should read about 5 V Turn unit off Short circuit the supply s output Turn unit DVM should read 0 to 4 V To check OVERVOLTAGE proceed as follows a Using test set up connect top end of 2 kQ resistor to J2 17 b With no load on supply turn OVP ADJUST fully CW and set VOLTAGE control for about 30 volts output Turn CURRENT control one turn CW c Turn OVP ADJUST CCW one half turn or until th
62. CHANGE k In the replaceable parts 115 page 6 8 change Fan tube axial 115 V to HP P N 3160 0301 When ordering new fan the hardware listed below must be ordered page 6 9 under Chassis Mechanical add screw EP P N 2370 0026 qty and nut HP P N 0590 0653 qty 4 CHANGE 5 In the replaceable parts list page 6 5 change R133 and R134 to 110 k 1 8 W 1 HP P N 0157 0466 On page 6 7 under FET Assembly add L2 and L3 ferrite bead HP P N 9170 0894 qty 2 CHANGE 6 In the replaceable parts list page 6 7 un der A3 FET Assembly change Q1 2 to FET dual T03 HP P N 5080 1991 ERRATA On page 1 3 under Programming Response Time change the first sentence to read Maximum time for output voltage to change from 2 V to 60 V Appendix B page B 2 under Programming Response Time change the first sentence to read Maximum time for output voltage to change from 2 V to 50 V or 50 V to 2 V and settle within the 200 mV band CHANGE T7 On page 6 8 under Main Board Mechanical change the quantity of contact terminal P N 1251 0600 from to 6 Under Front Panel Assembly Mechanical add Fan cable as sembly HP P N 8120 3468 qty 1 This fan cable assembly was soldered directly onto the circuit board now it is attached by means of two contact terminals the replaceable parts list page 6 9 under Chassis Mechanical add cable bushing HP P N 1251 6532 qty 1 ERRATA On page
63. CITOR C OF A DIODE OR THE EMITTER A TRANSISTOR 4 LOCATIONS FOR SEMICONDUCTORS ARE SHOWN BELOW VIEW Qi 4 3 COMMON ut5 5 ON VOLTAGE REGULATOR DEVICES REF SUPPLY BIAS FOR REGULATORS INTERNAL REFERENCE REF OUTPUT FROM REGULATORS INTERNAL REFERENCE BOOST OUTPUT CONTROL FOR EXTERNAL PASS TRANSISTOR CURRENT SENSE CURRENT LIMIT INV INVERTING INPUT TO REGULATORS ERROR AMPLIFIER NON INVERTING INPUT TO REGULATORS ERROR AMPLIFIER COMP FREQUENCY COMPENSATION A 19 oneureuos 200 2109 EPO 81 DAY pee ARSE 35435 AOSD mane 6 19 35 25 22 Ee 2 5 200 BOUNOR E 4 RONJ HOLINOH A 3 MOAINO A 90Md 9 SFY 20 Wick uve ANIN 95 GL Y Sd J tay AS a t T i NOWHOO YOAV TOS 90116 eee SALVAS FOV 21 xa 9 1315340 3 HOLY IOS 1009099 MO e 501715 a EIS Gay eon Ld NO eno E 390 00 sd SE 9 1 DRY AS t H AT HMHI AD Ot songs 1104050 mous nouo 22 BOLINO T TEINA 29 i 20 2 TENE Ao 2 H Sandy 50 22136 ov
64. DER T BUS BARS 1 SACRE 12 t 5 8 Do 7 50 Y s THOS wer 21 lt lt 5 J fal je BLK ATGWESSY 134 ey 99 134 19 3559 30000 vy KHS del ROIS 2 JA 33 A1BW3SSV 134 9 Figure 7 1 Top View Cover and Heatsink Cover Removed 7 2 Figure 7 2 Board A1 Component Location 7 3 adis YANIS 12 e 692860lllziel 3015 LN3NOdWNOO V8203JH M INN d 22120268 2 aeiy Figure 7 3 Control Board A2 Component Location 7 4 ACCESS FET SOURCE PINS ACCESS FET GATE PINS VIA RIGHT END OF R4 OR VIA LEFT END OF RS OR R2 THIS VIEW R4O THIS VIEW ACCESS FET DRAIN ON HEATSINK OR CONNECTING SCREWS A COMPONENT SIDE 1 SOLDER SIDE U 817 14 COMPONENT SIDE 1 2 3 9 22 SOLDER SIDE AB M M JF Figure 7 5 Output Diode Board A4 Component Location Figure 7 6 AC Filter Assembly Component Location 7 5 Table 7 1 Test Point Descriptions Test Point Option 002 Connector P2 Connector J1 Pin Pin No Description CV Amplifier Output CC Amplifier Output Constant Voltage Mode Low CV 12 V Unregulated 25 V OVP Remote Reset Input low reset CC Programming Input 15V Unregulated 25 V CV Programming input Bias Power Supplies Common Sense Primary Power Fault low low level or ac d
65. ER OUTPUT TO NOMINAL AC LINE VOLTAGE WHILE MONITORING AUTOTRANSFORMER OUTPUT CURRENT IN THIS AND IN FOLLOWING STEPS TURN AUTOTRANS FORMER BACK TO ZERO IF OUTPUT CURRENT EXCEEDS 750mA AUTOTRANS FORMER OUTPUT gt 750 YES NO REINSTALL A2 CONTROL BOARD DISCONNECT 2011 SLOWLY INCREASE AUTO TRANSFORMER OUTPUT TO NOMINAL AC LINE No CHECK AND ALL CIRCUITS OPERATING ON AUTOTRANS FORMER OUTPUT 750mA 45V REGLNOTE YES RECONNECT 204 AND DIS CONNECT 208 SLOWLY INCREASE AUTOTRANSFORMER OUTPUT TO NOMINAL AC LINE NO CHECK 208 AND ALL CIRCUITS OPERATING ON 712 REG NOTE 8 AUTOTRANS FORMER OUTPUT gt 150 YES RECONNECT 208 AND DIS CONNECT AZUIS SLOWLY IN CREASE AUTOTRANSFORMER d dd TO NOMINAL AC LINE CHECK A2U15 AND ALL CIRCUITS OPERATING ON 5V REG NOTE 1 AUTOTRANS FORMER OUTPUT T150mA NO YES 1 RECONNECT 2115 CHECK A2C43 A2C51 A2C52 A2UIT 2018 CHECK PC BOARDS CAREFULLY FOR SHORTS BE TWEEN CIRCUITS DISCONNECT GORA FROM TEST EQUIPMENT REPLACE Figure 5 9 Troubleshooting Bias Supplies NOTE TABLE 7 2 LISTS THE ACTIVE COMPONENTS OPERATING ON EACH BIAS SUPPLY REMOVE BOTH FET ASSEMBLIES AUTOTRANS FORMER OUTPUT gt 5 NO YES DISCONNECT AtQ2 FROM BOARD CHECK AIRIS AND AIVR2 SLOWLY IN CREASE AUTOTRANSFO
66. Erie Technological Products inc Erie PA 73138 Beckman Instruments Inc Helipot Division Fullerton CA 82389 Switchcraft Inc Chicago IL 84411 TRW Capacitor Division Ogallala NE 91637 Dale Electronics Inc Columbus NE CO633 Rifa Bromma Sweden Wima Mannheim Germany 6 2 Part No A1 1 4 0180 2889 5 6 0160 4355 C7 17 0160 5187 C8 0180 0426 C9 10 0160 3969 C11 12 0180 3049 C13 0160 4281 C14 0180 1916 C15 16 0180 2628 CR1 2 10 12 1901 0759 CR3 4 1901 1087 CR5 1901 0028 CR6 9 1901 0050 CR7 8 1901 0327 DS1 1990 0325 F1 2110 0063 J1 4 1251 6488 K1 0490 1267 L1 06012 80096 L2 9170 0707 06012 80003 L3 9170 0721 06012 80095 L4 9170 0061 06012 80004 L5 9140 0082 Q1 1854 0575 Q2 1854 0448 R13 0811 1892 R2 0811 1898 R4 0686 3015 R5 6 0811 1914 R7 12 0686 0275 R13 0811 1803 R14 15 0686 1645 R16 0686 1005 R17 0683 2035 R18 0686 4715 R19 0811 1559 R20 06012 80005 R21 0698 3428 2 3101 1914 T1 5080 1937 T2 06012 80093 T3 06012 80090 Ut 1906 0218 u2 1990 0593 U3 4 1906 0006 VRi 1902 3104 dio znr 5 62V 5 VR2 1902 3180 1 dio znr 11 8V 2 4 2 2 1 2 2 1 1 2 5 2 1 2 2 1 1 4 1 1 1 2 1 1 1 1 1 1 1 1 1 1 2 1 1 2 6 1 2 1 1 1 1 1 1 1 1 1 1 1 Table 6 4 Replacement Parts Description Main Board Assembly cap 3400uF 200V 10 50 cap OT1uF 10 250Vac cap 0 154 F 600V 224 10 100 250Vdc cap 015 20 2
67. FDH6308 SKC0221 TIP42A CB2015 EB1525 4715 CB3355 C4 1 8 TO 8251 F CB4315 NE55 CB1055 T2B 78 CB1035 4 1 8 1501 4725 CB3335 CMF 55 1 T 9 CMF 55 1 T 1 CB1535 CB2715 CXB2745 4 1 8 1331 1615 CR 25 1 4 5P2K7 C4 1 8 TO 90R9 F Desig Part Qty U16 17 U18 VR1 8 11 14 VR9 VR10 VR12 VR13 21 22 0757 0465 2100 3273 2100 0589 2100 3274 0686 2225 0757 0438 0683 4735 0686 1205 0683 1025 0683 0335 0757 0439 0683 6235 0683 3305 0683 0275 0698 0084 0683 3325 0683 1525 1990 0732 1990 0494 1826 0493 1858 0023 1820 1976 1820 1932 1820 2019 1820 1600 1820 1961 1826 0144 1826 0049 1826 0016 1902 0556 1902 0575 1902 0064 1902 3180 1902 0779 1810 0276 1810 0206 Table A 3 Replaceable Parts cont 1 1 3 2 1 2 1 1 2 1 1 1 2 2 1 1 1 3 3 2 1 1 1 1 1 1 1 2 1 10 1 1 1 1 1 1 Description res 100k 196 125W f res var 2k 10 res var 100 1096 25W res var 10k 1096 res 2 2k 596 5W fc res 5 11k 1 125W f res 47k 596 25W fc res 120 596 5W fc res 1k 596 25W fc res 3 30 596 25W fc res 6 81k 196 125W f res 62k 596 25 fc res 330 596 25W fc res 2 70 5 25W fc res 2 15k 196 125W f res 3 3k 5 25W fc res 1 5k 5 25W fc Opto isolator Opto isolator LM308A XSTR Array NPN si 14050 14538 IC MC14584BCP
68. GE CV CC SUPPLY TYPICAL SUPPLY a mmm Figure B 2 Output Characteristics Typical Dual Range and Autoranging Supplies B 30 PRINCIPLES OF OPERATION B 31 Section IV Manual Changes B 32 in paragraph 4 2 the reference illustration is now Figure 8 2 instead of Figure 4 1 Figure 4 2 and paragraph 4 9 change the dc input to the FET switches from approx imately 300 Vdc to approximately 250 Vdc B 33 MAINTENANCE B 34 Section V Manual Changes 35 paragraphs 5 9 5 17 c 5 28 c 5 44 f and 5 46 and 5 51 c change 20 V to 13 5 V 8 36 paragraph 5 9 change 3 40 to 3 138 B 37 in paragraphs 5 9 5 15 f 5 38 e and 5 41 e change 17 5 A to 16A B 38 In paragraphs 5 9 5 15 c d h 5 19 e 5 38 c 5 41 Table 5 4 line 6 and 5 103 b c change 60 V to 50 V B 39 In paragraph 5 9 change 1200 W to 910 W B 40 1 paragraphs 5 15 f 5 38 e and 5 41 e change 17 5 mV to 16 mV B 41 paragraph 5 19 change mV to 8 mV B 42 In paragraph 5 24 c change 40 V and 30 A to 35 V and 26 43 paragraph 5 31 change the values 30 0 1490 1 3330 1 4820 30 A and 27 A to 22 2 2 0 2020 1 8180 2 0200 22 and 19 8 A B 44 paragraph 5 32 replace the second sentence with the following Therefore at the same 40 V output the load would have decrease 0 720 from 4 000 to 3 280 to increase the output current by 2 2 A from 10 A to 12 2 A
69. Hz single phase 240 input Power 208 to 250 Vac 48 to 63 Hz single phase 910 One additional operating and service manual shipped with the power supply for each Option 910 ordered 1 17 ACCESSORIES 1 18 The System 11 Cabinet accessories listed below may be ordered with the power supply or separately from your local Hewlett Packard Sales and Service Office see list of ad dresses at the rear of this manuali HP Part No Description 5061 0089 Front handle kit for 5 1 4 inch high cabinets 1460 1345 Tilt stand 1 snaps into standard foot supplied with instrument must be used in pairs 5061 0077 Rack flange kit for 5 1 4 inch high cabinets will be shipped with instrument if ordered as Option 908 5061 0083 Rack flange front handle kit for 5 1 4 inch high cabinets will be shipped with instrument if ordered as Option 909 HP Part No Description 1494 0018 Slide kit for installing 17 inch deep cabinet in HP rack enclosure 1494 0025 slide kit same as 1494 0018 plus permits tilting instrument up or down 90 1494 0023 Slide adapter kit permits use of 1494 0018 kit in non HP rack enclosure of adequate depth 5060 2809 Control Board Extender card 1 19 ORDERING ADDITIONAL MANUALS 1 20 One manual is shipped with each power supply Ad ditional manuals may be purchased directly from your local Hewlett Packard Sales office Specify the model number in strument serial number prefix and the manual part nu
70. Power Requirements 2 2 2 17 Power Connection 2 2 2 20 Rack Mounting 2 3 2 22 AC LINE IMPEDANCE CHECK ee waite 2 3 2 25 LINE VOLTAGE OPTION CONVERSION 2 3 OPERATING INSTRUCTIONS 3 1 INTRODUCTION 3 1 3 4 TURN ON CHECKOUT PROCEDURE 3 1 3 6 CONNECTING THE LOAD 3 1 3 14 PROTECTIVE CIRCUITS 3 3 3 16 OPERATING MODES 3 3 3 19 NORMAL OPERATING MODE 3 3 3 27 Constant Voltage Operation 3 4 3 31 Overvoltage Protection OVP S oem ox dan tt 3 4 3 35 ALTERNATE OPERATING MODES 3 5 Section 3 37 3 42 3 61 3 67 3 82 3 96 Page Remote Voltage Sensing 3 5 Remote Programming 3 6 Auto Paraliel Operation 3 9 Auto Series Operation 3 10 Auto Tracking Operation 3 12 I MONITOR OUTPUT SIGNAL 3 14 PRINCIPLES OF OPERATION 4 1 DIFFERENCE BETWEEN AN AUTORANGING POWER SUP PLY AND A CONVENTIONAL POWER SUPPLY 4 1 43 SIMPLIFIED SCHEMATIC DESCRIPTION 4 1 4 5 Basic 4 4 4 8 input Circuits 4 1 4 17 Constant Voltage CV CIFGUIT asides Sirah oA 4 3 4 21 Constant Current CC 4 3 4 24 Control Voltage 4 4 4 27 Pulse Width Modulator 4 4 4 30 PWM Fast Off 4 4 4 32 Primary Current 1 Limit 4 5
71. R SHIPMENT 2 2 Before shipment this instrument was inspected and 2 8 To insure safe shipment of the instrument it is recom 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 If damage is found file claim with carrier immediately The Hewlett Packard Sales and Service office should be notified as soon as possible 2 3 Mechanical Check 2 4 This check should confirm that there are no broken controls connectors or indicators that the cabinet and panel surfaces are not dented or scratched and that the meters and plastic cover on rear panel are not scratched or cracked 2 5 Electrical Check 2 6 Section V of this manual contains complete verifica tion procedures for this instrument Section contains an ab breviated check which be used quickly to place the unit to operation Refer to the inside front cover of the manual for the Certification and Warranty statements TERMINAL STRIP USES 6 32 SCREWS ON 0 38 CTRS TERMINAL STRIP DETAIL 05 U2 Immy Figure 2 1 2 1 mended 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 Sales and Ser vice office to obtain the materials This office will also furnish the address of the nearest service
72. RMER OUTPUT TO NOMINAL AC LINE AUTOTRANS FORMER OUTPUT gt 750mA NO YES RECONNECT AIQ2 AND 015 CONNECT SLOWLY IN CREASE AUTOTRANSFORMER OUTPUT TO NOMINAL AC LINE AUTOTRANS NO FORMER OUTPUT gt TS0mA YES CHECK COMPONENTS OPERAT ING ON UNREGULATED BIAS SUPPLIES NOTE 1 AND ASSOCIATED COMPONENTS AND FAN REINSTALL 5 9 CHECK FET ORIVERS CHECK 02 ASSOCIATED COMPONENTS CHECK RELAY DRIVER b Connect a 50 ohm 40 watt load resistor across output terminals c Connect a digital voltmeter DVM across output ter minals to monitor output voltage d Turn VOLTAGE and CURRENT controls to mid range 5 turns and OVP ADJUST control to maximum fully CW e Hemove top cover f An extender card HP Part No 5060 2809 can used with the A2 Control Board to allow easy access to components 5 60 Overall Trouble Isolation 5 61 Once the test setup is arranged proceed to the ov troubleshooting tree in Figure 5 8 This tree will isolate trouble to a particular circuit Table 5 3 provides information that the user who understands the operation of the circuit as described in Section IV can use with standard troubleshooting procedures to locate the trouble 5 62 The following notes apply to ali troubleshooting pro cedures 1 Before removing or replacing components turn power off and disconnect ac power cable 2 Allow two min
73. T IMPEDANCE dkHz FREQUENCY DC OUTPUT ISOLATION Either output terminal may be floated up to 240 Vdc including output voltage from ground 1 3 OVERVOLTAGE PROTECTION Trip voltage adjustable from 2 V to 63 V Minimum setting above output voltage to avoid false tripping is 1 5 V 196 of VouT REVERSE VOLTAGE PROTECTION Maximum permissible current caused by reverse voltage impressed across output terminals 50 continuous 20 A continuous with ac power off REMOTE SENSING Maintains nominal voltage at load by correcting for load lead voltage drop of up to 0 5 per lead REMOTE PROGRAMMING Resistance Programming 0 to 2 5 provides zero to max imum rated voltage or current output Accuracy CV 1 3mV CC 2 596 15 Voltage Programming 0 to provides zero to maximum rated voltage or current output Accuracy 0 3 CC 196 15 Current Programming 2 mA to 0 mA current sink provides zero to maximum rated voltage or current output with user provided 2 5k resistor Accuracy CV 0 3 0 42V accuracy of resistor CC 1 0 8A accuracy of resistor PROGRAMMING RESPONSE TIME Maximum time for output voltage to change from 0 V to 60 V or 60 V to 2 V and settle within 200 mV band Up Full load 3 4Q 120 ms No Load 120 ms Down Full Load 3 40 400 ms No Load 1 2s Typical response time to settle within 200 mV band for excursions other than full sca
74. The manual references the correct label 1 thus requiring no change to the manual CHANGE 14 In the replaceable parts list page 6 4 un der A2 board add CR4O and CRh1 HP P N 1901 0033 qty 2 On the schematic Figure 7 9 connect CR40 cathode end to 2 1 and anode end to TB1A5 Connect CRh1 cathode end to 1 5 and anode end to TB1A8 ERRATA In the replaceable parts list page 6 7 un der FET Assembly change Q1 2 previo usly changed in change 6 to HP P N 1855 0473 CHANGE 15 In the replaceable parts list page 6 3 un der Al Main Board Assembly change VR2 to zener 11V 2 P N1902 3172 1 Also make this change to the Schematic Diagram figure 7 9 CHANGE 16 In the replaceable parts list for Option 002 page 15 change U7 8 to HP P N 1826 0986 CHANGE 17 In the replaceable parts list page 6 8 change Fan tubeaxial to HP P N 3160 0259 CHANGE 18 Diodes and CR41 added in change 14 have been moved from the A2 Terminal Block to the A2 PC Board They are now located on the A2 PC Board as follows CRhO is next to and CRU1 is next to R18 Make these additions on page 7 figure 7 3 Control Board 2 component location Electrically CRhO and CRhi are connected as decribed in CHANGE 14 In the replaceable parts list page 6 h under A2 Control Board Assembly add C60 O luf 50V HP P N 0160 4722 TQ 1 On page 6 6 add R180 1K 5 1 4W HP P N 0683 1025 TQ 1 R181 56
75. This assumes that the AC DROPOUT signal from the AC Dropout Detector Siow Start Circuit is not present AC DROPOUT operates through the Bias Voltage Detector to inhibit the power circuits Upon turn on the one second delay provided by AC DROPOUT ordinarily exceeds the time re quired for the bias voltage to reach the proper level 4 48 The Bias Voltage Detector also inhibits the power circuits in brownout conditions if the ac line voltage falls below approximately 7096 of nominal SECTION V MAINTENANCE 5 1 INTRODUCTION Before returning the power supply to normal operation repeat the applicable portions of the performance test to ensure that 8 amp 2 Upon receipt of the power supply the performance the fault has been properly corrected and that no other fauits test Paragraph 5 5 can be made This test is suitable for in exist coming inspection If a fault is detected in the power supply while making the performance test or during normal opera 5 3 TEST EQUIPMENT REQUIRED tion proceed to the troubleshooting procedures After troubleshooting and repair Paragraph 5 52 perform any 5 4 Table 5 1 lists the test equipment required to perform necessary adjustments and calibration Paragraph 5 86 the various procedures described in this section Digital Multimeter Table 5 1 Test Equipment Required REQUIRED CHARACTERISTICS RECOMMENDED Sensitivity 1 mV Bandwidth 20 MHz USE MODEL
76. This voltage is amplified and buffered by the i Monitor Amplifier A2U2 to isolate the power supply output from cur rents in the CC Circuit Comparison Amplifier 206 com pares the I Monitor signal to the CC Programming Voltage In normal CC mode the output from the CC Circuit also varies between 0 5 volts and 1 0 volts and is applied to diode 2 19 4 23 Differentiator circuit A2UTA and UIB compensates for highly reactive loads CC Clamp AZUSA limits the current output from the instrument to no more than 55 amperes 4 24 Control Voitage 4 25 The outputs of the CV and CC Circuits are applied to diodes that connect to a wired OR junction Whichever cir cuit is requesting less power wiil forward bias its output diode and determine the voltage at the wired OR junction As stated earlier the outputs vary between 0 5 volts and 1 0 volts with the more negative levels representing lower power demands The wired OR junction at the anodes of A2CR18 and A2CR19 is biased to 1 5 volts Therefore whichever cir cuit CV or CC produces the more negative output will cause its output diode to be forward biased and thereby determine the Control Voltage This Control Voltage is compared to the Ramp Voltage to determine when the FET switches are turned off 4 26 For example assume the output from the CV Circuit 2068 is 0 2 volts and the output from the CC Circuit 206 is 0 9 volts A2CR18 will be forward bias
77. ULATION Constant Voltage Less than 0 0196 of output voltage plus 3 mV for any line voltage change within rating Constant Current Less than 0 0196 of output current plus 5 mA for any line voltage change within rating PARD Ripple and Noise 20 Hz to 20 MHz Constant Voltage Less than 5 mV rms and 50 mV p p Constant Current Less than 25 mA rms TEMPERATURE COEFFICIENT Constant Voltage Less than 0 0196 plus 2 mV change in output per degree Celsius change in ambient after 30 minute warmup Constant Less than 0 01 plus 4 mA change in output per degree Celsius change in ambient after 30 minute warmup DRIFT Stability Change in output over an 8 interval under constant line load and ambient temperature after 30 minute warmup Constant Voltage Less than 0 03 of output plus 5 mV Constant Current Less than 0 03 of output plus 5 mA LOAD TRANSIENT RECOVERY TIME Less than 2 ms is required for output voltage recovery in constant voltage operation to within 100 mV of the nominal output following a change in output current of 1096 of max imum current rating at any output voltage output current 5A RESOLUTION Minimum output voltage or current change that can be ob tained using the 10 turn front panel controls Constant Voltage 20 mV Constant Current 20 mA OUTPUT IMPEDANCE Typical 0 2 9 dc See graph OUTPU
78. UT LOCKWASHER WASHER UI PLASTIC SPACER fener PRINTED CIRCUIT BOARD SCREWS Figure 5 12 2015 Mounting Hardware a Remove eight screws from heatsink cover two screws hold heatsink cover to fan bracket six screws fasten heatsink cover to FET board and output diode board assemblies and lift cover off b Pull assembly upward to unplug it from main board c When replacing assemblies be certain to replace assembiies in proper locations With user facing front panel the FET board assemblies fit in left and center sockets with printed circuit board facing left The output diode board assembly fits in right socket with printed circuit board facing right d After replacing FET board and output diode board assemblies replace heatsink cover Be certain all six plastic in serts two in each heatsink are properly located under screw holes in heatsink cover Start screws into plastic heatsink in serts carefully and do not over tighten CAUTION To prevent heatsinks from shorting together do not operate power supply without heatsink cover in place Be certain that all six plastic heatsink in serts are properly located under heatsink cover holes and engaged by six heatsink cover screws 5 71 FET Board Disassembly 5 72 To disassemble a FET board proceed as follows a Unsolder both wires from thermostat b Remove four screws that secure FETs and heatsink to prin
79. V 5 25 Noise Spike measurement Techniques An in strument of sufficient bandwidth must be used when making a high frequency spike measurement Measuring noise with an instrument that has insufficient bandwidth may conceal high frequency spikes that could be detrimental to the load The oscilloscope listed in Table 5 1 should be operated with the bandwidth limited to 20 MHz modest increase in noise spike amplitude may be observed above 20 MHz 5 26 A single ended measurement replacing RMS voltmeter in Figure 5 3 with an oscilloscope is usually not ade quate for measuring spikes a differential oscilloscope is necessary Because of its common mode rejection a differen tial osciloscope displays only the difference 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 the oscilloscope case Before using a differential input oscilloscope however it is imperative that the common mode rejection capability of the oscilloscope be verified Turn both the VOLTAGE and CURRENT controls fully counterclockwise short together the two input leads at the power supply and observe the trace on the CRT If the trace is a straight line then the oscilloscope is properly ignoring any common mode noise present if the trace is not a straight line then the oscilloscope is not rejecting the ground signal and must be realigned in accord
80. VM across current monitoring resistor Ray e Reduce resistance of load until DVM reads 17 5 mV in dicating that current output is exactly 17 5A maximum rated power output Ensure that power supply remains in constant voltage mode by checking CV light f Disconnect DVM from Ray and reconnect DVM to power supply sense terminals g Place power supply in temperature controlled oven DVM remains outside oven Set temperature to 30 and allow 30 minutes warm up h Record DVM reading i Raise temperature to 40 C and allow 30 minutes warm up j Observe DVM reading Difference in voltage reading be tween steps h and j should be less than 80 mVdc 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 resistance and ambient temperature are all held constant 5 40 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 con stant during the period of measurement The supply should be located away from any source of stray air current If possible place the supply in an oven and hold it at a constant temperature Take care that the measuring instrument has an eight hour stability a
81. _ O 2 5K PROGRAMMING RESISTOR SSS SS SS ee eS SS p CONSTANT CURRENT i SOURCE 4 e d i SENSE rr ines rre mnie Serre mm Figure A 3 Resistance Programming of Output Voltage And Or Current 5 2 CONTROL BOARD d CC CIRCUIT CONSTANT AMPLIFIER CURRENT lt SOURCE cc PROGRAMMING VOLTAGE SOURCE 0 5 CC PROG VOLTAGE OUTBOARD SENSE CV PROG VOLTAGE Figure 4 Voltage Programming of Output Voltage And Or Current A 6 AZ CONTROL BOARD CV CIRCUIT CURRENT 1 SINK 1 0 2 n t CIRCUIT i ome i 1 Deep 1 m REG 4 1l p i i i E m Pa oo ENIM CONSTANT CURRENT SOURCE DU LL ncs mL 45 REG E see TEXT AND FIGURE 6 TO DETERMINE VALUE OF SERIES RESISTOR IF REQUIRED 0 5W Ww 30 CURRENT SINKS CAN CONNECT TO POWER SUPPLY 15 REG OR TO AN EXTERNAL NEGATIVE SUPPLY THAT 1 REFERENCED TO 6012 A POWER SUPPLY COMMON Figure 5 Current Programming Output Voltage And Or Current A 30 The 0 to 2 mA current sink will cause the output of op amps 08 and 07 to vary proprotionaily from 0 to 5 volts With relays K2 and
82. able parts list page 6 3 add CRih HP P N 1901 0050 1 On the schematic Figure 7 9 add CRIL across 92 Base cathode to Emitter anode CHANGE 9 In the replaceable parts list page 6 4 change C27 to cap 3 3 uF 5 15V HP P N ee 0180 2264 Model 6012 Page 3 CHANGE 10 This change also applies to the following _ serial numbers 2207A 009h9 2207 00950 207A 00952 Change L2 and L3 previously added in CHANGE 5 to Inductor 0 15 uH HP P N 9100 1610 qty 2 In the replaceable parts list page 6 7 under FET Assembly change R9 to res 110 k 1 1 8 W HP P N 0757 0466 CHANGE 11 In the replaceable parts list page 6 3 change A1Q2 to HP P N 1854 0456 and on page 6 8 under Al Main Board Mechanical delete spacer plastic Q2 HP P N 1200 0181 CHANGE 12 1n the replaceable parts list page 6 7 un der 5 Front Panel Assembly add the follow ing note to Rh When replacing Rh check the casing style If the casing is square order the Rh HP P N 2100 3252 listed the manual If the casing is round order HP P N 2100 2216 Both resistors are the same value but because of their different casing sytle they not interchangeable 13 the replaceable parts list page 6 8 un ier Chassis Electrical Parts change 16 to HP P N 06012 80099 ERRATA The Terminal Block reference printed on the A control board is incorrectly labeled TB2 and should be labeled 1
83. ance of the 6012A power supply illustrations for Op tion 002 are given in Appendix included in this section are a Top view of unit with covers removed Figure 7 1 showing sub assembly locations chassis mounted com ponents main board mounting screws troubleshooting test points and wire colors b Component location diagrams Figure 7 2 through 7 6 showing the physical location and reference designators of aimost al electrical parts Front panel mounted components are identified by lettering on the board and front panel c Test point description table Table 7 1 listing the signals at the 26 pin edge connector P2 and the 16 pin option 002 jack J1 at the top of the A2 Control Board d Bias supplies table Table 7 2 listing the semiconductor components operating on each bias supply 7 1 e Logic symbols diagram Figure 7 7 illustrating the logic symbols used on the schematic ft Power supply waveforms Figure 7 8 illustrating waveforms found at key points in the power supply 9 Schematic diagram Figure 7 9 including case outline drawings for each of the semiconductor components used in the power supply The test points shown on the schematic are described in Table 7 1 WARNING Wait two minutes after turning power off for in put capacitors to discharge before performing any maintenance procedures avoid excess ve in rush current do not operate relay manually Load Enc C24 UN
84. and A 33 change maximurn rated voltage or current output or full scale voltage to 50 V or 50 B 58 SCHEMATIC B 59 Schematic Changes B 60 Change R135 located in the Overvoitag Protection circuit to 24 9 kQ 1 8 W Change R151 located in the Over voltage Protection Circuit to 182 1 8 W Also change the dc input to the FET switches from approximately 300 256 is x uA
85. anel controls and indicators see Figure 3 1 and ensures that the supply is operational This check should be performed when the unit is first received If the supply faiis to perform properly proceed to the troubleshooting procedures in Section V a Ensure that rear terminal board straps are connected as shown in Figure 3 3 but do not connect load Check that rear panel label indicates unit is set for line voltage to be used If it is not refer to Section Il Line Voltage Option Conversion If unit is equipped with System Option 002 ensure that option cable is disconnected from rear panel option connector before proceeding b Ensure that CURRENT control is rotated clockwise at least two turns and OVP ADJUST potentiometer screwdriver adjust is fully clockwise Press pushbutton LINE switch on pushbutton in and observe that green LINE indicator turns on and that fan operates d Turn VOLTAGE control 3 through output voltage range of unit as indicated on voltmeter Green VOLTAGE light 4 should be across entire range indicating that supply is in constant voltage mode e Check overvoitage circuit by turning OVP ADJUST con tro counterclockwise until output voltage drops Output voltage should drop to 0 volts and red OVP 9 and OUTPUT UNREGULATED 5 indicators should light 3 1 f Reset overvoltage circuit by returning OVP control to maximum clockwise position and turning supply off for at least two seconds an
86. ansistor zener ZNR Table 6 3 Code List of Manufacturers Code Manufacturer Address 00853 Sangamo Electric Company Pickens SC 01121 Allen Bradley Company Milwaukee 01295 Texas Instruments Semicon Comp Division Dallas TX 01686 RCL Electronics inc Manchester NH 02111 Specctrol Electronics Corporation City of ind 03508 G E Company Company Semiconductor Products Department Auburn NY 04713 Motorola Semiconductor Products Phoenix AZ 06776 Robinson Nugent Inc New Albany 1 07263 Fairchild Semiconductor Division Mountainview CA 12954 Siemans Corporation Components Group Scottsdale AZ 14604 Elmwood Sensors inc Cranston Ri 14936 General Instrument Corporation Semicon Products Hicksville NY 16299 Corning Glass Works Component Division Raleigh NC 19701 Mepco Electra Corporation Mineral Wells TX 20932 Emcon Division ITW San Diego CA 24546 Corning Glassworks Bradford 27014 National Semiconductor Corporation Santa Clara CA 27167 Corning Glassworks Wilmington NC 28480 Hewlett Packard Palo Alto CA 2M627 R Ohm Corporation irvine 31918 ITT Schadow Minneapolis MN 32997 Bourns Inc Riverside CA 31585 Corporation Solid State Division Somerville NJ 4 833 ETRI Inc Monroe NC 54473 Matsushita Electric Corporation of America New York NY 56289 Sprague Electric Company North Adams MA 71400 Bussman Division of McGraw Edison Company St Louis MO 72982
87. ard zero from the readings that existed when the overtemperature condition occurred If the ac input voltage drops below approximately 70 of nominal the bias voltage detector will shut down the output this case the QUTPUT UNREGULATED indicator is on all other indicators are off and the meters read zero immediately 3 16 OPERATING MODES 3 17 This power supply is designed so that its mode of operation can be selected by making strapping connections on its rear panel Normal operating mode for this power supply uses local programming of the output voltage and current via the front panel VOLTAGE and CURRENT controls and local sensing of the output voltage Alternate operating modes allow use of remote programming remote voltage sensing and multiple power supply combinations 3 18 The following paragraphs first describe operating considerations with the normal operating mode using the strapping pattern as it is connected at the factory Later paragraphs cover alternate operating modes The operating considerations described with normal mode such as constant voltage constant current crossover overrange constant voltage and constant current operation and overvoltage pro tection apply to the alternate modes as well as to normal mode More theoretical descriptions regarding the operational features of power supplies in general are given in the DC Power Supply Handbook Application Note 90B available at no charge from your local Hewlet
88. ate Method of Remote Control The REMOTE INHIBIT input J2 31 provides an alternate method of remote shutdown By maintaining a low logic level at this input the supply s output will be inhibited until REMOTE IN HIBIT is returned to its initial high state The following paragraph provides a brief description of this circuit see schematic diagram and Figure A 7 A 51 A low logic level at REMOTE INHIBIT is coupled through opto isoiator U6 and causes USF to inhibit the supply and light the OVP indicator in the same manner as the REMOTE TRIP input of paragraph A 49 Note that this action does not affect the Trip Reset latch and therefore the supply can be returned to its initial state by switching the REMOTE INHIBIT input to a high logic level 52 Power On Preset A 9 A 53 This open collector output line J2 6 provides logic low pulse POWER ON PRESET that can be used to in itialize or delay system operation until the 5 V REG bias sup ply in the 6012A has stabilized The pulse is generated after primary power is turned and also after resumption of power following momentary ac dropout or brownout condi tions in which ac line voltage drops below approximately 7096 of nominal See Table A 1 for POWER ON PRESET signal specifications A 54 Low Bias Or AC Dropout Buffers These circuits distribute the ORed outputs of the AC Dropout and Bias Voltage Detector circuits in the 6012A mainframe paragraphs 4 42 through 4 48 Th
89. be tween and AB ac gain from S to 2 pin 1 both referenced to should be unity at 22Hz 2 7 at 60Hz and 5 5 at 120Hz OVP Circuit 1 With OVP ADJUST fully CCW OVP light should be on output voltage should be lt 2 and test point A2P2 9 should be low Otherwise check A5R4 A2J2 and cable from front panel A2U19A 209 2010 A2VRS and associated com ponents 2 When OVP is tripped A2U19A non inverting input pin 3 should be more positive than inverting input pin 2 and A2U19A output pin 1 2010 base should be high 3 With OVP ADJUST fully CW turn power supply off for at least two seconds and then back on Test point A2P2 8 should be high OVP light should be off and output voltage is determined by setting of VOLTAGE control Bias Voltage Detector Dropout Detector 1 A fuil wave rectified 120Hz sine wave of approximately 16 volts peak should be present at A2P1 16 Otherwise check that A2 control board is properly aligned and fully seated and check A1CR6 and 1 9 2 Output of dropout detector ramp circuit at A2U13B pin 1 should be 5V use high impedance voltmeter 10MQ 3 Output of slow start ramp circuit at A2U13C pin 14 should be 4 2016 8 should be 0 7V 5 A2U16A pin 7 should be lt 0 2V 5 63 REPAIR AND REPLACEMENT 5 65 remove top cover remove the three screws one at each side and one at center of rear panel that secure top WARNI
90. cond delay when A2R23 is turned up k Repeat steps c through i as necessary until 5V bet ween and A5 produces 50A 0 2 output current and 10mV between and A5 produces 100mA output current Turn off power supply and disconnect shunt 5 98 Constant Current Source Adjustment 5 99 The constant current source adjustment is made with a resistor whose value is known within 0 1 connected directly between terminals 7 and S on the rear panel The nominal value of the resistor should be between 1 k and 2 7 k A value of 1 k is recommended for ease of calculating current flow through the resistor Proceed as follows a Remove the strap between terminals A8 and A7 b Connect resistor between A7 and S c Connect digital voltmeter DVM across resistor d Turn power supply on and adjust A2R24 for 2 mA 0 2 through resistor For example if a 1 resistor is used DVM reading of 2 V indicates 2 mA through resistor e Turn power supply off disconnect resistor between and 5 and reconnect strap between and 7 5 100 Ammeter Adjustment 5 101 The CC full scale and CC offset adjustments must be correct before adjusting the ammeter circuit To adjust the ammeter circuit proceed as follows a Connect 1 shunt across output terminals b Connect digital voltmeter DVM across shunt c Turn on power supply and adjust CURRENT control for 0 05 t0 1mV on DVM 50 A 100mA output d Adj
91. controlling the on time of the FET switches On pulses are initiated by a clock cir cuit Off pulses are initiated when current flow in the primary has stored enough energy for the output circuit which is determined as follows 4 7 The output voltage and current are compared to reference voltages set by front panel controls to produce a control voltage The control voltage indicates the amount of power required by the output circuit Current flow in the primary circuit produces a ramp voltage that represents the amount of energy being stored for transfer to the output cir cuit An off pulse is generated when the ramp voltage exceeds the control voltage 4 8 Input AC Circuits 4 9 Primary power is connected through the Filter to the LINE switch and contacts of relay A1K1 When the LINE switch closes current flows through 181 and A1R3 and the input Bridge Doubler to charge the Input Filter A jumper in 60V 20V 50A C MODEL 6042 AUTORANGING 1000W SUPPLY Figure 4 1 Output Characteristics Typical Dual Range and Autoranging Supplies S INT HAMO BOLE TOGON HIG ISW ARMAND p LOCHA ov uo Seg an TOD 1 i SUDAHI D llli o 7 i i 4935 8076 Jedi f NOSRVNDO 22 dS an I i I ine Les rm pin
92. cuit and full load 5 44 Current Output and Ammeter Accuracy To check that the supply will furnish its rated output current pro ceed as follows Connect test setup shown in Figure 5 2 Operate the load in constant resistance mode Amps Voit with resistance in itially set to minimum b Turn VOLTAGE control fully clockwise c Turn on supply and adjust CURRENT control until DVM reads 50 mV indicating that current output is exactly 50A maximum rated output current d Front pane ammeter should indicate 3 e Disconnect DVM from and connect DVM to power suppiy sense terminals f increase resistance of load until DVM reads exactly 20V maximum rated power output Ensure that power supply re mains in constant current mode by checking CC light g Disconnect DVM from power supply sense terminals and reconnect DVM across Rag h DVM should indicate 50 mV front panel ammeter should indicate 50A 3 5 45 Load Effect Load Regulation Definition The change in the static value of the dc output current Alg jT resulting from a change in load resistance from short circuit to a value which yields maximum rated output voltage or from the latter value to short circuit 5 6 5 46 To check the constant current load effect proceed as follows a Connect test setup shown in Figure 5 2 b Turn VOLTAGE control fully clockwise Turn on supply and adjust CURRENT control until DVM reads 50 mV indicating tha
93. d devices should be used to in terface these output lines to logic circuits A 39 a The following signals are in active low form CV MODE J2 36 indicates that the power supply is in constant voltage operation CC MODE J2 35 indicates that the power supply is in constant current operation OUTPUT UNREGULATED J2 18 indicates that the power supply is in neither constant voltage nor constant current operation and cannot be guaranteed to meet specifications OVERVOLTAGE J2 17 indicates power supply shut down because of the voltage output exceeding the OVP trip point set at the front panel or a system initiated shutdown as described in Section A 45 OVERTEMPERATURE J2 16 indicates power supply shutdown due to an excessive temperature rise on the FET or output diode heatsink b A 40 The LOW 5 OR AC DROPOUT signal J2 19 is in active high form This signal indicates loss of primary power momentary AC dropout or brownout conditions where the AC line voltage drops below approximately 7096 nominal 41 Remote Control 42 proper operation of the opto isolators the user must supply the bias voltage CONTROL ISOLATOR BIAS This voltage can be from 4 75 to 16 V depending on the requirements of the driving circuits The type of driving logic and resultant bias voltage also determine the amplitude of the high and low logic levels Refer to the Specification Table A 1 A 43 Co
94. d then back on Output voltage should return to value set in step d 9 To check constant current circuit turn off supply and connect short AWG 8 or larger across and output ter minals on rear panel Ensure that VOLTAGE control is rotated at least two turns clockwise h Turn supply back on and rotate CURRENT control through output current range of unit as indicated on ammeter Green CURRENT light 7 should be across entire range indicating that supply is in constant current mode i Turn off supply remove short from output and read re mainder of operating instructions before connect ng actual load to supply ien run m Figure 3 1 Front Panel and Indicators 3 6 CONNECTING THE LOAD 3 7 Load connections to the power supply are made at rear panel and bus bars Wires may be connected to any of the three pairs of connecting screws on the bus bars Stranded wires should be terminated with an appropriate size terminal To satisfy safety requirements the wires to the load should be at east heavy enough not to overheat while carrying the power supply output current that would flow if the oad were shorted Table 3 1 lists some single wire sizes and two wire combinations and the current carrying capacity they pro vide Generally heavier wire than that listed in Table 3 1 is re quired to obtain good regulation at the load If the load regula
95. de Board Disassembly 5 74 disassemble the output diode board proceed as follows a Unsolder both wires from thermostat b Unsolder both wires from output diode at points A and B on printed circuit board c Remove three screws two of which secure Q1 that secure heatsink to printed circuit board d Q1 plugs into pins that are soldered to printed circuit board Do not unsolder these pins Carefully unplug Q1 NOTE When replacing Q1 output diode or thermostat you must spread a thin layer of heatsink com pound between component and heatsink See note following Paragraph 5 68 step g for recom mended compound e Before re assembly of output diode board ensure that plastic insulators for Q1 leads remain in heatsink Figure 5 13 shows TO3 component mounting f Ensure that two pins for Q1 leads are standing straight up from printed circuit board g Mate printed circuit board with heatsink ensuring that two Q1 lead pins fit into two holes heatsink h Carefully mate Q1 leads with pins extending into heat sink from printed circuit board i Replace three screws that secure Q1 and heatsink to printed circuit board j Re solder output diode wires to points A and B on printed circuit board Ensure good solder connections because these connections carry the full output current up to 50A 5 75 A1 Main Board Removal 5 76 The main board is held in place by 16 86 32 screws see Figure 7 1 These 16 screws incl
96. detected including ac turnoff 4 38 long carryover bias supply associated with the Down Programmer stores enough energy to operate the Down Programmer after loss of primary power This ensures that the Down Programmer will be able to discharge the out put circuit completely when primary power is turned off 4 33 Overvoltage Protection Circuit OVP 4 40 The Overvoltage Protection Circuit monitors the out put voltage across the output line and circuit common output If the output voltage exceeds a preset limit set by the front panel OVP ADJUST potentiometer the Over voltage Protection Circuit inhibits the PWM triggers the Down Programmer and latches itself until the instrument is turned off 4 5 4 41 The Overvoltage Protection Circuit operates from the long carryover bias supply associated with the Down Pro grammer By ensuring that the reference voltage remains high until after the output reaches zero volts when the instru ment is turned off this feature prevents the Overvoltage Pro tection Circuit from latching if the unit is turned back on again immediately after turn off 4 42 AC Dropout Detector Slow Start Circuit 4 43 This circuit contains two ramp circuits The slow start ramp holds the output of the AC Dropout Detector Slow Start Circuit AC DROPOUT low for imately one second after the instrument is turned The AC DROPOUT signal operates through the Bias Voltage Detector to
97. djust oscilloscope to display transients as in Figure 5 6 g Recovery of power supply output voltage to within 100 mV of nominal output voltage should be within two milliseconds 5 35 Temperature coefficient Definition The change in output voltage per degree Celsius change in ambient temperature measured while ac line voltage output voltage setting and load resistance are ali held constant 5 36 The temperature coefficient of a power supply is measured by placing the unit in an oven and varying the temperature over any span within the power supply s rating The power supply temperature must be allowed to stabilize for a sufficient time at each measurement temperature 5 37 The temperature coefficient given in the specification table 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 38 To check the temperature coefficient proceed as follows a Connect load and digital voltmeter as iliustrated in Figure 5 2 b Turn CURRENT control fully clockwise Turn on supply and adjust VOLTAGE control until digital voltmeter DVM indicates exactly 60V maximum rated out put voltage d Disconnect DVM from power supply sense terminals and connect D
98. e all precautions outlined in the remote programming paragraphs Simultaneous use of remote sensing and remote programming is also possible dur ing auto series operation 3 82 Auto Tracking Operation 3 83 Figure 3 17 shows the interconnections required to operate two or more units in auto tracking mode This mode of operation allows multiple supplies that share a common negative or positive output bus to power separate loads and have their output voltages simultaneously programmed by the voltage and current controls of the master supply The output voltage of each slave supply varies in direct proportion to that of the master The ratio of each slave s output voltage to the master s is established by the ratio of the resistors in the voltage divider connected between S of the master and 5 of the slave MASTER 2544557 977 2240 voc peces At iS SLAVE 4 3249 voc Iure vent Figure 3 17 Auto Tracking Operation 3 84 Figure 3 18 shows the interconnections required to provide both positive and negative outputs from an auto tracking combination As can be seen the oniy difference from standard auto tracking operation is that the output terminal of slave 2 instead of the output terminal is con nected to the common bus There is no limit to the number of supplies that can be operated in either auto tracking con figuration SLAVE 3t4 X240 SLAVE 2 2249 VE
99. e cover Be certain to replace the toad although the spikes are inductively isolated from the cover after making connections power supply To minimize voltage spikes at the load connect a bypass capacitor as shown in Figure 3 2 With this setup 3 9 If multiple loads are connected to one supply each peak peak noise at the load can actually be reduced to a level load should be connected to the supply s output terminals well below the value specified at the 6012A output terminais using separate pairs of connecting wires This minimizes mutual coupling effects between loads and takes full advan tage of the supply s low output impedance Each pair of con necting wires should be as short as possible and twisted or shielded to reduce noise pickup 3 13 Before operating the power supply read the paragraphs in this section concerning protective circuits nor mal operating mode and any sections of alternate operating modes relevant to your application 3 10 load considerations require the use of output distribution terminals that are located remotely from the sup ply then the power supply output terminals should be con nected to the remote distribution terminals by a pair of twisted or shielded wires and each load should be separately con nected to the remote distribution terminals Remote voltage POWER SUPPLY sensing is required under these circumstances Paragraph 3 37 A BYPASS CAPACITOR 3 11 Either positive or negative voltage
100. e input signal arrives at J1 13 active low form and is distributed active high to opto isolator U1 and to the Power On Preset circuit A 55 Multiple Supply System Shutdown A 56 When using more than one 002 equipped power supply in a system it may be desireable to implement a system shutdown this configuration an OVP trip or remote shut down of a single unit will cause of the suppiies to shut down A 57 Figure A 8 shows one method of system shutdown The advantages of this method are that one common is used for all status and controi lines useful for controller operated systems and the capability of system reset As shown in Figure A 8 one supply s OVERVOLTAGE line is connected to the next supply s REMOTE TRIP line and so on in a tinuous chain 5 V REG POWER SUPPLY COMMON from Supply 1 can be used instead of the bias voltage from the controller However because of current limits of the 5 V REG no more than four units can be connected together this configuration To prevent ground loops do not parallel connect 5 REG from more than one supply Figure A 8 System Shutdown Using Controller Power Supply A 58 The note following Paragraph A 49 teils how to determine if a shutdown was initiated through the remote trip line or by a supply s OVP This allows the controller to deter mine which supply initiated a system shutdown A 58 Following a multiple supply shutdown each unit ca
101. e of the 2 5k resistor connected between and CAUTION if the DAC is turned off or the program leads open the output current will tend to rise above rating The supply will not be damaged if this occurs but the VOLTAGE control should be ad justed such that the supply will switch to CV mode once the output current reaches the highest level the load can absorb and or the OVP AD JUST should be set to shut down the supply 3 9 240 VDC 4 TO Hs CURRENT SINK 0 2 Figure 3 13 Current Programming of Output Current 3 61 Auto Parallel Operation 3 62 Figure 3 14 shows the rear panel interconnections re quired to auto parallel two or more units This mode of opera tion provides a greater current capability than can be obtained from a single supply while ensuring that each supply will share the load proportionally to its own total power capability under load conditions For example if a 1000W supply and 200W supply were auto paralleled the 1009W supply would provide 5 6 the total current and the 200W supply would pro vide 1 6 the total current The 6012A can auto paralleled only with other autoranging units or with units that have current monitoring output signals that are internally refer enced to the output and equal to 5V at maximum rated current output Any number of supplies may be connected in auto parailel NOTE Use wire of equal length and gauge to connect each a
102. e opera tion at this preset voltage limit and the output current drops proportionately setting the voltage limit make an adequate allowance for high peak voltages that could cause unwanted crossover 3 31 Overvoitage Protection OVP 3 32 Adjustment The overvoltage trip point is adjusted with the single turn OVP ADJUST screwdriver control on the front panel The approximate trip voltage range for this unit is from two volts to 63 volts When the overvoltage protection circuit trips the supply is inhibited and delivers no output power the OVP and OUTPUT UNREGULATED indicators on the front panel light Rotating the control clockwise sets the trip voltage higher It is set to maximum at the factory 3 33 When adjusting the OVP 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 out put would falsely trip the OVP For this reason it is recom mended that the OVP trip votlage be set higher than the out put voltage by at least 1 5 volts 1 of the output voltage To adjust the OVP trip voltage proceed as follows a With OVP ADJUST control fully clockwise no load con nected turn on supply b Set output VOLTAGE controi to desired trip voltage c Turn OVP ADJUST control counterclockwise until OVP circuit trips red OVP indicator lights and output voltage falls to zero d Turn off supply and turn down output voltage e Turn
103. e slaves should be set above the desired output voltage to avoid interference with the master 3 64 Overvoltage Protection in Auto Parallel Adjust the OVP trip point at the master supply The slave supply OVP control s may be set to the same level or to maximum fully clockwise to disable them If the master OVP trips the master will program the slaves to zero output If a slave OVP trips it shuts down only that slave the other units supply more cur rent until the master switches to CC mode 3 65 Auto Parallel with Remote Sensing To combine auto parallel operation with remote sensing connect the sup ply as described above but remove the S and 5 jumpers from the master supply and connect the S and 5 ter minals directly to the and ends of the load Observe the 3 68 Figures 3 15 and 3 16 show the rear panel intercon precautions outlined under Paragraph 3 37 nections required to operate two or more supplies in auto Figure 3 15 Auto Series Operation 3 10 series This mode of operation provides a greater voltage capability than can be obtained from a single supply As many as four supplies can be connected in auto series in the con figuration shown in Figure 3 15 and as many as eight supplies can be connected if the power supply combination and load are center tapped as in Figure 3 16 with no more than four supplies on each side of the center tap Either configuration allows all the supplies to be programmed
104. e sup ply goes into overvoitage DVM should read 0 to 4 V d Turn OVP ADJUST fully CW turn supply off and wait several seconds e Turn supply on DVM should read about 5 volts 82 To check OUTPUT UNREGULATED proceed as follows a Using test set up connect top end of 2 kQ resistor to J2 18 b With no load on supply turn OVP ADJUST fully CW and set VOLTAGE control for about 30 volts output Turn CURRENT control one turn CW c Turn OVP ADJUST CCW one haif turn or until the sup ply goes into overvoltage DVM should read O to 4 V OVP ADJUST fully turn supply off and wait several seconds e Turn supply on DVM should read about 5 volts A 83 To check LOW BIAS OR AC DROPOUT proceed as follows a Substitute an oscilloscope in place of DVM in test set up b Connect top end of 2 kQ resistor to 12 19 Turn unit on Voltage at 2 resistor should be be tween 0 and 4 V d Turn unit off Voltage at 2 k resistor should go to about 5 volts before decaying back to OV NOTE this test the LOW BIAS OR AC DROPOUT signal decays to O V only because of loss of power to the 5 V REG Bias Supply used in the test set up in doubt use an external 5 sup ply for this test A 84 To check OVERTEMPERATURE proceed as follows a Turn off power supply and disconnect line cord b Wait at least two minutes for input capacitors to discharge c Remove top cover and remove heatsink cover d Using
105. ected to output terminals 5 17 power supply capacitors to discharge completely b Insert a small blade screwdriver in meter adjust screw about one inch below meter face and turn screw until pointer points to zero mark on scale 5 92 Ip Limit Adjustment 5 93 The lp limit adjustment ensures that the power sup ply will provide maximum output power under worst case conditions With power supply turned off proceed as follows a Connect load and shunt to power supply output ter minals as in Figure 5 2 Operate load in constant current mode and adjust load to draw more than 52A b Connect digital voltmeter DVM across input bus input bus voltage can be monitored between ends of R6 and R5 toward front of instrument on main board see Figure 7 1 Note that this voltage is referenced to the ac line c Connect a second DVM across shunt d Connect power supply ac input to a variable autotransformer Turn VOLTAGE and CURRENT controis both fully clockwise and turn lp limit adjust A2R20 fully counterclockwise f With autotransformer set at zero volts turn power sup ply on increase autotransformer voltage until input bus voltage is 300 Vdc Adjust 2820 for 52 mV across shunt 52A output h Decrease load current for 50 mV across shunt 50 output i Disconnect DVM from shunt and connect DVM across output terminals Adjust A2R20 for 22V output 0 1V k Adjust autotransformer for 240 Vdc input
106. ed and the wired OR junction will be held at 0 8 volts includes the 0 6 volt drop across A2CR18 A2CR19 will be reverse biased so the CC Circuit will have no effect 4 27 Pulse Width Modulator 4 28 The FET switches are turned on and off at a 20 kHz rate by signals derived from the Pulse Width Modulator PWM On pulses are initiated by the 20 kHz Clock signal Off pulses are initiated when the Ramp Voltage which in dicates the amount of energy being stored for transfer to the output circuit exceeds the Control Voltage which indicates HOLDS PWM 20kHz CLOCK RESET A2UM OUTPUT 2 INITIATES the amount of power required by the output circuit Figure 4 3 is a timing diagram showing the relationship of various signals that control the FET switches 4 29 The more negative level of the 20 kHz A2U11 output resets both flip flops A2U9B and A2USA and holds them reset until the 2011 output goes positive Then the next positive edge from the output of the 320 kHz Oscillator triggers A2U9B triggering and one shot multivibrator A2U12A The FET switches are turned on current flows through Power Transformer A1T2 and Ramp Voltage starts to rise When Ramp Voltage exceeds the Control Voltage the output of A2U5 changes state and flip flop A2USA is reset triggering one shot multivibrator A2U12B to produce an off pulse 4 30 PWM Fast Turn Off 4 31 Figure 4 3 shows that there is a delay between the
107. efficient and stability specifications of the supplies and Ry must be stable low noise resistors with temperature coefficients of less than 25 ppm and power ratings at least 10 times what they will actuaily dissipate 3 91 The front panel VOLTAGE control of the slave can be used in place of Ry by connecting a strap from A7 of the slave to AB of the slave This enables the user to vary the ratio of the slave output voltage to the master output voltage For calcula tion purposes use a resistance value of 2 7k for the VOLTAGE control when it is set to maximum 3 92 Setting the Current Controls The current controls of all supplies in an auto tracking combination are in dependently operative and can be used to set current limits for each individual load If the master supply goes into the con stant current mode the output voltages of the slaves continue to track that of the master if a slave goes into constant cur rent mode however no other supply is affected 3 93 Overvoitage Protection in Auto Tracking Set the OVP of each supply as appropriate for the load connected to that supply if the master supply OVP trips the master will program the slaves to zero output if a slave OVP trips only that slave and its load will be affected 3 94 Auto Tracking with Remote Sensing To com bine auto tracking operation with remote sensing connect the supplies as described above but remove the S and S jumpers from each supply
108. el sets the OVP trip point between 2V and 63V red LED on the front panel indicates that OVP has tripped 1 5 Output connections are made to bus bars on the rear panel Either the positive or negative output terminal may be grounded or the output may be floated up to 240Vdc including output voltage from ground 1 6 Remote programming remote or local voltage sens ing and several methods of operating multiple supply com binations for increased output voltage or current capability are possible by making connections to rear panel terminals These capabilities are more fully described Section IH 1 7 The 6012A is considerably smaller lighter and dissipates less power than older design supplies with similar output power capability The unit is fan cooled and is pack aged in a Hewlett Packard System li compatible modular enclosure which is sturdy attractive and provides easy ac cess for servicing 1 8 SAFETY CONSIDERATIONS 1 9 This product is a Safety Class 1 instrument provided with a protective earth terminal The instrument and this manual should be reviewed for safety markings and instruc tions before operation The Model 6012A Autoranging Power Supply provides 1 1 1 10 SPECIFICATIONS 1 11 Detailed specifications for the power supply are given in Table 1 1 1 12 INSTRUMENT AND MANUAL IDENTIFICATION 1 13 Hewlett Packard power are identified by a two part serial number The first part
109. ent Shunt Model 9992 Catalog 41218 50 mV Current Monitoring Resistor Measure output current calibration 5 5 PERFORMANCE TEST 5 6 The following test can be used as an incoming inspec tion check and appropriate portions of the test can be repeated to check the operation of the instrument after repairs The tests are performed using the specified nominal input voltage for the unit If the correct result is not obtained for a particular check proceed to troubleshooting Paragraph 5 52 5 7 Measurement Techniques 5 8 specifications should be measured at the power supply terminals Also all tests are performed with the supply strapped for local programming and sensing as shown in Figure 3 3 The wires used to connect the load to the supply should be heavy enough to ensure that they will drop less than 0 5 If the supply is equipped with System Interface Option 002 remove the interface Option cable from the connector and check the power supply first Then proceed to the checkout procedure in Appendix A to test the Option 002 components 5 9 Select A Load Specifications are checked with vary ing amounts of load resistance connected across the supply For most of the constant voltage tests the value of load resistance must be approximately 0 4 Q to permit operation of the supply at 20V and its maximum output power rating cur rent of 50A For the constant current tests the load re
110. er any listed changes s in the manual 4m HM ym WW dA OP A SERIAL MAKE lt CHANGES Prefix Number lt 11 Errata 19h6A 00101 00140 1 20 00141 00260 1 2 21164 00261 00300 1 3 2121A 00301 00540 1 5 8 2136A 00541 00680 1 6 8 2147A 00681 00770 1 7 8 220hA 00771 00810 1 8 2207 00811 00960 1 9 10 2213 00961 01110 1 10 2228A 01111 01360 1 11 2231A 01361 01585 1 12 2302 01586 01935 1 13 2329 01936 02260 1 18 2h02A 02261 02285 1 14 2h0hA 02286 02335 1 15 2405A 02336 02360 1 16 2406A 02361 02385 1 17 2412A 02386 02485 1 18 2420A 02486 02635 1 19 2426A 02636 02642 1 19 2426A 02642 02891 1 20 2526 02892 02908 1 21 2426A 02909 1 20 2426A 02910 1 21 2451A 02911 up 1 22 ERRATA In paragraph 2 2h step should also be performed with a full load as described in step c On page B 2 change INPUT POWER specifica tions to Two internal switches and two in ternal jumpers permit operation from 100Vac 10 4565 48 63 Hz Maximum input current is 2h A rms values for 120 220 Spec
111. eviewed before attempting to troubleshoot the unit Often the user will then be able to isolate a problem sim ply by using the operating controls and indicators Once the principles of operation are understood refer to the following paragraphs 5 55 Section Vii contains a schematic diagram and infor mation concerning the voltage levels and waveforms at many of the important test points Section VII also includes compo nent location diagrams to help the user locate the unit s com ponents and test points Most of the test points used for troubleshooting the supply are located on the control board test fingers which are readily accessible at the top of the board CAUTION To avoid damaging the 6012A be careful not to short circuit test points together The safest prac tice is to turn the 6012A off while connecting and disconnecting test instruments 5 56 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 adjustment portions of this section It may be necessary to perform one or more of the ad justment procedures after a component is replaced 5 57 Initial Troubleshooting Procedures 5 58 If a problem occurs follow the steps below in se quence a Check that input power is available and check the power cord and rear panel circuit breaker If breaker trips while power is on or if breaker is found to be tripped at any time for unknown rea
112. f 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 slaves are disabled The current con trols of the slaves should be set above the desired output cur rent to avoid having a slave switch to CC mode NOTE The current controls of the slave supplies can be disabled by disconnecting the straps between the and A4 terminals and connecting a resistor between A3 and A5 on each slave The resistor value should be chosen to program a current greater than the desired output current See Paragraph 3 57 3 11 MASTER 4240 VDC E 240 VDC 10 Figure 3 16 Auto Series Operation Positive and Negative Outputs 3 73 Resistor Values As shown each slave has an exter nal voltage divider and Ry that determines its program ming voltage The ratio of Ry to determines the ratio of a slave s output voltage to the output voltage of its master the next more positive supply To determine the value of Ry and Rx first choose the ratio of the slave output voltage to the output voltage of its master Ys select value for Ry and then determine the value for Ry by solving this equation Rx 12 Vs For exampie assume a two supply combination that is to pro vide 90 50 volts from the master and 40 volts from the slave if we select a value of 1k f
113. graph 3 22 which refers to Figure 3 4 in the manual the reference illustration is now Figure B 1 instead of Figure 3 4 Also the CURRENT setting should be changed from 30 A to 22 A and the resistance from 1 30 to 1 820 B 22 in paragraph 3 24 change the values 2 20 2 20 0 70 and 25 V to 3 139 3 130 0 550 and 22 V B 23 in paragraph 3 25 change 1000 W to 675 W This should also be done for every remaining 1000 W value in the manual B 24 In paragraph 3 32 change 63 volts to 52 voits B 25 in paragraph 3 46 3 51 3 53 3 54 and 3 56 change full scale or maximum or maximum rated output voltage to read 0 to 50 V or 0 to 50 A 26 Remote Programming in paragraphs 3 46 3 51 3 53 3 54 and 3 56 to obtain the 0 50 V output different pro gramming values are now necessary for Constant Voltage than those required for Constant Current Output Resistance Programming requires 2083 programming resistance Voltage Programming requires a 0 4 17 V programming voltage and Current control requires a 2083 KQ resistance with a 2mA to 0 mA current sink The Constant Current Output programming values for Option 100 are the same as those shown n the manual B 27 In paragraph 3 51 change 25000 to 20830 B 28 paragraph 3 52 change 12500 30 V 12500 25000 and 20 V to 10420 25 V 10420 20830 and 16 67 V B 29 paragraphs 3 53 and 3 54 change O to 5 V to UO to 417 V 0 16 88 9 16 88A B DUAL RAN
114. h cable entrance h Fold connector shield assembly 6 and secure with three screws i Strain relief set screw 3 can now be adjusted from top of connector to clamp firmly on cable j Clip fasteners 7 onto ends of connector pin housing 2 k Connector can now be plugged onto option connector J2 and secured with two screws 8 into the threaded stand offs on either side of J2 A 18 OPERATION A 19 The following paragraphs provide the operating in structions necessary to interface an 002 equipped power sup ply into an automated system brief description of the cir cuits is also provided connections are made at the 37 pin rear panel connector J2 Figure A 2 and can be wired directly into the mating connector supplied for this purpose OUTBOARD SENSE zisy RES CC CURRENT PROG CURRENT PROG CURRENT MON TOR 15V REG SENSE 5 REG VOLTAGE MONITOR CC RES amp VOLT PROG CV RES 8 VOLT PROG USED REMOTE RESET POWER ON PRESET POWER SUPPLY COMMON USED 1 CONTROL ISOLATOR BIAS CC CURRENT PROG ENABLE REMOTE TRIP CV CURRENT PROG ENABLE e REMOTE INHIBI NOT OVERTEMPERATURE USED STATUS ISOLATOR COMMON CC MODE OVERVOLTAGE CV MOOE OUTPUT UNREGULATED LOW BIAS OR AC DROPOUT STATUS ISOLATOR MAS Figure A 2 Rear Panel Connector J2 A 20 Remote Programming 21 Resistance Control Figure 3 it is neces
115. he instru ment and the 11V used by the FET drivers Also provided from the Power Supply circuits are the 120Hz pulse input to the AC Dropout Detector Slow Start Circuit and the 5V unregulated voltage input to the Bias Voltage Detector These two circuits operate as described in later paragraphs to pro duce the relay enable signal that controls relay A1K1 4 11 Current flow from the input rails through Power Transformer A1T2 is controlled by a parallei pair of FET switches in each of the two identical FET and FET driver cir cuits On and off signals for the FETs are derived from the Pulse Width Modulator as will be described shortly The on pulses are applied through drivers A3U2A U2B and and transformer A3T1 to the gates of FETs 1 and Q2 Although the on puise is less than 2 microseconds duration the FETs input capacitance holds the FETs on after the on pulse has disappeared 4 12 When the FETs are turned on current flows through the primary of Power Transformer A1T2 One of the leads for 1 2 serves as the primary for Current Monitor Transformer A1T1 Output Diode A4CR1 is reverse biased and blocks cur rent flow through A1T2 secondary Consequently energy is stored in the field that builds around the A1T2 transformer windings The longer that voltage is applied to the primary the more energy is stored 4 13 Current flow in the secondary of A1T1 develops the Ramp Voltage across resis
116. hould be properly pears as a parallel pair of resistors to the power supply An adjusted to protect the user s load equivalent resistance of 5k will approximately double the up 3 7 240 VOC CURRENT SINK O 2mA Figure 3 9 Current Programming of Output Voitage 3 57 Resistance Programming of Output Current The rear panel connections shown in Figure 3 10 allow the output current to be varied by using an external resistor to program the supply The discussion in Paragraphs 3 51 and 3 52 for constant voltage operation also applies for constant current operation CAUTION the programming terminals A2 to A5 become open circuited during resistance programming the output current will tend to rise above rating The supply will not be damaged if this occurs but the user s load may be damaged If there is possibility that the programming leads may be opened it is suggested that the optional resistor be connected directly across terminals 5 and A2 as shown in Figure 3 10 The value of this resistor should be selected to limit the output current to the maximum that the load can handle without damage For example if the toad can handle 25 amperes one half of full scale 1250 ohm resistor should be connected from A5 to A2 Remember that the resistance value actually pro gramming the supply is the parallel combination of the programming resistor and the optional resistor 3 8 240 VOC
117. iates an off pulse when Ramp Voltage exceeds the Control Voltage at A2U5 and Ramp never reaches lp Limit at A2U13D However if the Control Voltage is excessively high both VOLTAGE and CURRENT controls set to relatively high values Ramp will exceed Limit The output of A2U13D changes state initiating an off pulse 4 34 As an additional protection feature if nothing else resets flip flop A2USA such as the control circuit overtemperature low bias or ac dropout or overvoitage it wilt be reset by the next negative level from 2011 triggering A2U12B to generate an off puise Therefore maximum duty cycle of the FETs is always less than 5096 4 35 The Limit Comparator also includes a slow start circuit which limits the output power the unit can provide un til after the 1 1 relay contacts close completely 4 36 Down Programmer 4 37 This circuit allows the output voltage to be lowered rapidly when required order to lower the output voltage it is necessary to discharge the output filter capacitors typically through the load situations that require the output voltage to drop more rapidly than can be accomplished through the load the Down Programmer pulls the output line to a low level and dischaiges the capacitors This action can be triggered by any of three conditions The CV Circuit programs a much lower output voltage an overvoltage is detected on the out put or low bias or ac dropout is
118. ifications for 120 220 and 240 Vac are given in Table 1 1 In paragraph B 53 change HP P N of R136 to 0698 4486 R151 to 0757 0471 On Figure 7 9 change R19 bet _ and output lines just to right of own Programmer to 6 In the Overvoltage the wiper of A5R4 is and 240k Vac connected to J2 2 Eliminate PEAK INRUSH CURRENT 1 In the replaceable parts list for A2 Control Board Assembly add CR31 HP P N 1901 0033 and R89 1M ohm 5 HP P N 0683 1055 change CR19 to HP P N 1901 0033 CR3i is mounted next to C31 with its cathode con nected to 19 and its anode connected to R57 R89 is mounted betueen the cathode end of CR19 and the end of R60 closer to U6 On the schematic add CR31 and R89 to the out put of the CC Circuit as shown below The operation of the CC Circuit is essen tially the same as described in paragraphs 4 21 through h 26 except that there is an extra diode drop in the output of the Circuit C11 9 055 CRANGE 2 In the replaceable parts list make the fol lowing changes on page 6 3 R20 from HP P N 06012 80005 to HP P N 06012 80006 on page 6 5 R27 from HP P N 0698 6335 900 ohm to HP P N 0698 6341 750 ohm On page 6 5 R8 from HP P N 0757 0413 392 ohm to P N 0757 0410 301 ohm CHANGE 3 In the replaceable parts list page 6 9 un der Chassis Mechanical add bumper feet HP P N 05023 0266 qty 3 Model 6012A Page 2
119. inhibit the power supply output This one second delay allows the Input Filter capacitors to charge slowly through 1 1 and A1R3 4 44 The dropout detector ramp operates to shut down the instrument when primary power is turned off or lost This ramp circuit is ordinarily reset by the 120 Hz pulses in the unregulated 5 V If the ramp is not reset within approxi mately 20 milliseconds of the previous reset the output of the AC Dropout Detector goes low AC DROPOUT AC DROPOUT inhibits the power supply output as described in the following paragraphs 4 45 Bias Voltage Detector 4 46 The Bias Voltage Detector inhibits operation of the power circuits if the bias voltage drops below a certain level This is the level at which sufficient voltage is available to operate the control circuits reliably 4 47 When the instrument is turned on the outputs of the Bias Power Supplies begin to rise from zero volts When the output of the regulated supply reaches approximately 1 volt transistors in the Bias Voltage Detector turn on and per form the following functions inhibit the On pulse Off pulse PWM trigger the Down Programmer and inhibit the Relay Enable signal When the 5V unregulated supply teaches approximately 7 volts the OFF pulse is enabled When the 5V unregulated supply reaches approximately 9 volts the On pulse and PWM are enabled the Down Pro grammer trigger is removed and the Relay Enable signal is generated
120. into overrange if the load resistance continued to decrease to a 0 7 ohm value the supply would automatically come out of overrange and into the constant current mode at the 40A 25V point The supply will probably go out of regulation while operating in the over range region refer to Paragraph 3 26 325 Anytime the supply operates in overrange the VOLTAGE and CURRENT indicators turn off and the OUTPUT UNREGULATED indicator lights The VOLTS and AMPERES meters indicate the voltage and current being supplied to the output The product of the two readings will exceed 1000 watts Paragraph 3 14 identifies conditions other than over range which cause the OUTPUT UNREGULATED indicator to light 3 26 The supply can operate in the overrange region beyond the rated output power boundary for sustained periods without being damaged However the supply is not guaranteed to meet specifications in overrange Output ripple increases substantially and regulation is seriously degraded As an operator aid the maximum available load current for each voltage setting is indicated on a secondary scale of the voltmeter Similarly the maximum available load voltage for each current setting is indicated on the ammeter NOTE Under certain conditions of line and load is possible for the supply to provide more than rated output power and still maintain regulation If this occurs the unit will operate normally and the QUTPUT UNREGULATED indicator wi
121. is the serial number prefix a number letter combination that denotes the date of a significant design change and the country of manufacture The first two digits of the prefix indicate the year 20 80 21 81 atc the second two digits indicate the week and the letter designates the USA as the country of manufacture The second part of the serial number is a different sequential number 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 this manual a yellow Manual Changes sheet supplied with the manual defines the difference between your instrument and the instrument described by this manual 1 15 OPTIONS 1 16 Options are standard factory modifications that are requested by the customer The following options are available with this instrument Option 002 is described in Appendix A Option 100 is described in Appendix B Option No Description 002 Systems Option allows the supply to operate automatically in system applications Provides resistance voltage and current programming of output voltage and current six isolated status lines three isolated control lines 5V and 15 bias voltages This option is mounted on a single additional printed circuit board which includes a rear panel connector 100 Input Power 87 to 106 Vac 48 to 63 Hz single phase Output 675 W 50 V 50 A 220 input Power 191 to 233 Vac 48 to 63
122. k Do not use any compound containing silicone organic zinc oxide cream such as American Supply Company Heatsink Compound 100 is recommended See Figure 5 12 for location of mounting hardware h When replacing control board carefully line up con nector on bottom edge with socket on main board i Carefully press control board down so it is properly aligned and fully seated in main board socket Control board is fully seated when printed circuit board presses against both ends of main board socket Do not push down on any com ponents on control board j Replace two screws that secure control board to side panel k Reconnect from front panel to J2 socket Red tracer is to front of instrument white dot on control board i Reconnect cable from option card if installed to J1 socket Red tracer is to front of instrument white dot on con trol board Incorrect replacement will damage option board m Reconnect any wires disconnected from terminal block 5 69 A3 FET Boards and A4 Output Diode Board Removal 5 70 The two FET board assemblies and the output diode board assembiy plug into sockets on the main board and are held in place by the heatsink cover which is screwed to the fan bracket To remove these assemblies proceed as follows WARNING Wait two minutes for input capacitors to discharge before removing heatsink cover or per forming any maintenance procedure N
123. le Down On graph read difference in time between initial out put voltage and final output voltage add settling time of 200 ms full load or 330 ms no load 200 300 DOWN PROGRAMMING TIME mS 400 500 Table 1 1 Specifications Model 6012A continued Up On graph read time for change in output voltage UP PROGRAMMING TIME mS CURRENT MONITORING OUTPUT 0 to 5 V output from rear panel terminal indicates zero to maximum rated current output accuracy 1 10 mV out put impedance 10k METERS AND INDICATORS Voltmeter Continuously reading 70 V scale with secondary scale indicating amperes available accuracy 3 of full scale Ammeter Continuously reading 60 A scale with secondary scale indicating volts available accuracy 3 of full scale VOLTAGE Indicator Green LED indicates Constant Voltage operation CURRENT Indicator Green LED indicates Constant Cur rent operation OUTPUT UNREGULATED Indicator Red LED indicates that output is unregulated because of any of the following conditions overrange operation overvoltage over temperature or low input power shutdown OVP Indicator Red LED indicates shutdown caused by voltage at output terminals exceeding preset limit OVERTEMPERATURE indicator Red LED indicates shut down because of FET or output diode overtemperature 1 4 MULTIPLE UNIT OPERATION Auto Parallel Any number of units may be connected in to inc
124. ling Device light Fuse Filter Jack Relay inductor Meter Plug Transistor Resistor Switch Transformer Terminal Block Thermostat Integrated Circuit Voltage Regulator zener diode Wire jumper Oscillator 6 1 6 4 ORDERING INFORMATION 6 5 To order a replacement part address order or inquiry to your local Hewlett Packard sales office see lists at rear of this manual for addresses Specify the following information for each part Model complete serial number and any Option or special modification J numbers of the instrument Hewlett Packard part number circuit reference designator and description To order a part not listed in Table 6 4 give a complete description of the part its function and its location Table 6 2 Description Abbreviations AL Aluminum AWG American Wire Gauge CAP Capacitor CC Carbon Composition CER Ceramic C F Capacitor CONN Connector DIO Diode DPDT Double Double Throw Film FC Carbon Film Composition FET Field Effect Transistor F S Full Scale FW BRDG Full Wave Bridge GEN PRP General Purpose integrated Circuit MET POLY Metailized Poly propylene MO Metal Oxide NO Normally Open POLY E Polyester PW Power Wirewound PWR Power RECT Rectifier RES Resistor SI Silicon SW PB Switch Pushbutton SW SL Switch Slide SW THRM Switch Thermal TA Tantalum TBAX Tube Axial TRMR Trimmer VAR Variable XFMR Transformer XSTR Tr
125. ll be off However the slightest change in either line or load may cause the unit to go out of regulation Operation of the unit beyond the rated output power boundary is not recommended under any circumstance 3 4 3 27 Constant Voltage Operation 3 28 To adjust the supply for constant voltage operation a Turn on supply and with output terminals open adjust the VOLTAGE control for the desired output voltage Then turn power off b Connect a short across the rear panel and output terminals restore power and adjust the CURRENT control for the desired maximum output current Then turn power off and remove the short If a load change causes this currrent limit to be exceeded the supply automatically crosses over to con stant current operation at this preset current limit and the out put voltage drops proportionately In setting the current limit make an adequate allowance for high peak currents that could cause unwanted crossover 3 29 Constant Current Operation 3 30 To adjust the supply for constant current operation a With supply turned off connect a short across the rear panel and output terminals turn the power on and ad just the CURRENT control for the desired output current b Turn power off open the output terminals and adjust the VOLTAGE control for the desired maximum output voltage If a load change causes this voltage limit to be exceeded the supply automatically crosses over to constant voltag
126. lows a Connect test setup shown in Figure 5 2 b Turn CURRENT control fully clockwise c Turn on supply and adjust VOLTAGE control until DVM indicates 20V d Disconnect DVM from power supply sense terminals and connect DVM across Ry e Adjust resistance of load until DVM reads 50 mV in dicating that current output is exactly 50A maximum rated output current Ensure that power supply remains in constant voltage mode by checking CV light f Disconnect DVM from and reconnect DVM to power supply sense terminals g Open dc circuit breakers on load to disconnect load h Record voltage indicated on DVM i Close dc circuit breakers on load to reconnect load j Wait a few seconds only to allow DVM to settle Reading on DVM should not differ from reading of step h by more than 7 mV 5 18 Source Effect Line Regulation Definition The change in the static value of dc output voltage AEg jT 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 19 To check the source effect proceed as follows Connect test setup shown in Figure 5 2 b Connect variable autotransformer between input power source and power supply ac power input c Adjust autotransformer for low line voltage Paragraph 2 15 d Tum CURRENT control fully clockwise on power supply and adjust VOLTAGE control until DVM indicates exactly 60V f Disconnect DVM fr
127. mber provided on the title page When ordered at the same time as the power supply additional manuals may be purchased by adding Option 910 to the order and specifying the number of additional manuals desired Table 1 1 Specifications Model 6012A All performance specifications are at rear terminals with a resistive load INPUT POWER Two internal switches and two internal jumpers permit operation from 120 220 or 240 Vac 1396 696 48 63 Hz Maximum input current is 24 A rms for 120 Vac 15 rms for 220 Vac and 14 A rms for 240 Vac EFFICIENCY Typical 8096 on maximum output power boundary INPUT PROTECTION The ac input is protected by a rear panel mounted 25 A cir cuit breaker PEAK INRUSH CURRENT Maximum 120 Vac 31 5 A 220 Vac 13 3 A 240 Vac 14 3 A DC OUTPUT Adjustable from 0 to 60V and 0 to 50 A Maximum output power is 1000 W at 50A 1050 W at 60V and approximately 1200 W at mid range See graph 1 2 OUTPUT VOLTAGE 30A OUTPUT CURRENT LOAD EFFECT LOAD REGULATION Constant Voltage Less than 0 01 of output voltage plus 5 mV for a load change equal to the maximum available cur rent rating of the supply at the set voltage Constant Current Less than 0 0196 of output current plus 5 mA for a load change equal to the maximum available voltage rating of the supply at the set current Tabie 1 1 Specifications Model 6012A continued SOURCE EFFECT LINE REG
128. n AC Filter Assembly 0160 4355 PME271Y510 C18 19 cap 1 10 250Vac C20 0160 4962 cap 1 4 20 250Vac MKS4 R 1 0 250 2096 CB1 3105 0126 circuit breaker 25A 250Vac R22 0686 8245 res 820k 596 0 5W 8245 TBI 0360 1214 term biock 3 term Chassis Electrical Parts Bi 3160 0328 fan tubeaxial 115V 125XR 2182 C21 0180 3049 cap 2600F 10 50 75Vdc 101262T075A J2A L6 choke line L7 choke RFi S1 3101 0447 sw DPDT 1 01 0003 06 none N302UTVSEE Main Board Mechanical 2110 0269 0380 1265 1200 0181 0360 1750 0360 1843 0362 0669 1205 0397 1251 0600 fuseholder clip type F1 spacer press in 1 spacer plastic Q2 contact terminal single CR4 terminal stud R1 2 3 5 6 13 contact terminal single W1 heat sink U1 contact terminal single W2 J5 J6 Control Board Mechanical 0340 0166 1200 0181 1205 0267 0340 0503 insulator bushing Q1 spacer plastic 08 011 heat sink U15 insulator U15 FET Assembly each Mechanical 06012 20001 heat sink 01 02 28480 0340 0166 insulator bushing Q1 02 28480 1251 5318 contact connector single Q1 Q2 28480 0360 1843 terminal stud R1 R2 28480 1390 0513 fastener plastic cover 28480 Output Diode Board Mechanicai 06012 20002 heat sink CR1 01 28480 0340 0166 insulator bushing Q1 28480 1251 5318 contact connector Q1 28480 0360 1843 termi
129. n be reset individually or all the REMOTE RESET lines can be tied together for a system reset A 60 it is necessary to have all the supplies come up simultaneously after a system shutdown follow this pro cedure a First bring the REMOTE INHIBIT line low b Provide a negative going pulse to the REMOTE RESET lines After at least one second return REMOTE INHIBIT to a high level A 61 Figure A 9 shows a second method of system shut down This method is appropriate in systems which are not controller operated and in which more than four supplies must be shutdown simultaneousiy Because each supply derives its CONTROL ISOLATOR BIAS from the previous supply s REG there is no limit to the number of supplies that can be shutdown Each supply must be reset individually A 62 Using either method of system shutdown LOW BIAS OR AC DROPOUT inhibits the OVERVOLTAGE in dicator from going low and shutting down succeeding sup plies upon initial turn on After the supplies have stablizied LOW BIAS OR AC DROPOUT returns to a high state Figure A 9 System Shutdown Using 6012A Bias Supply Output A 63 Remote Local Programming A 64 When using current programming of output voltage and or current it is possible to leave the front panel controls operable This allows the user to switch back and forth be tween remote and local programming while initially checking out a current programming system For this function the 6012
130. nal stud R3 28480 1390 0513 fastener plastic cover 28480 Front Panel ssembly Mechanical insulator DS 1 6 28480 cable assembiy 28480 6 8 Table 5 4 Replacement Parts continued Ref HP Mfr Desig Part No Description Code Chassis Mechanical 06012 00004 1 chassis and rear panel 28480 06012 00006 1 top cover 28480 06012 00007 1 bottom cover 28480 5040 7201 4 foot 28480 06012 00002 i 1 front panel 28480 5020 8803 1 frame front 28480 5040 7202 1 trim strip top 28480 5060 9803 2 handle assembly 28480 5001 0439 2 trim side vinyl 28480 5040 7234 4 handie trim plastic 28480 06012 00012 1 bracket meter 28480 06012 00003 1 bracket fan 28480 06012 00009 1 bracket capacitor 28480 1390 0514 4 fastener plastic snap bus bars 28480 06012 00011 2 bus bar 28480 4040 1686 1 cover output bus 28480 06012 00010 1 heat sink cover 28480 06012 00005 1 panel ac filter assembly 28480 0100 0300 1 cable clamp strain relief line cord 28480 06024 00011 1 cover option 002 access hole 28480 Miscellaneous 0360 0523 jumper terminal block 28480 9211 3487 packing carton 28480 9220 1401 packing floater pad 28480 9220 3390 packing carton filler 28480 6 9 SECTION VII COMPONENT LOCATION ILLUSTRATIONS AND CIRCUIT DIAGRAMS 7 1 This section contains component location diagrams a schematic diagram and other drawings and tables useful for mainten
131. nd change meter amps to HP P N 1120 1901 ERRATA In the replaceable parts list page 6 9 un der Miscellaneous change jumper terminal block to HP P N 0360 2187 In the replaceable parts list page 6 8 un der FET Assembly change contact connector to HP P N 1251 7600 qty 2 CHANGE 21 In the replaceable parts list page 6 9 un der Chassis Mechanical change front panel to HP P N 06012 00002 TQ 1 and change bracket meter to HP P N 06012 00012 TQ 1 On page 6 7 under Front Panel Assembly change meter volts to HP P N 1120 1392 TQ 1 and change meter amps to HP P N 1120 1393 TQ 1 1 23 85 SECTION IV PRINCIPLES OF OPERATION 4 1 DIFFERENCE BETWEEN AN AUTORANGING POWER SUPPLY AND A CONVENTIONAL POWER SUPPLY 4 2 The main difference between an autoranging power supply and conventional types of constant voltage constant current CV CC power supplies can be seen by comparing the output characteristics of each conventional CV CC power supply can provide maximum output power at only one combination of output voltage and current as shown in Figure 4 1 The range of a power supply can be extended by design ing an instrument with two or more switch selectable voltage current ranges within the maximum power output capability as shown in Figure 4 1B The 6012A autoranging power supply provides maximum output power over a wide and continuous range of voltage and current combinations as shown if Figure 4 1C without the
132. nnect the bias voltage to J2 10 CONTROL ISOLATOR BIAS and reference the input signals to this bias supply s negative terminal 44 Two optically isolated methods of remote control are available They are described in the following paragraphs A 45 Remote Trip A negative going edge applied at in put J2 30 REMOTE TRIP will shut down the power supply reducing its output voltage to near zero For minimum pulse duration and timing considerations with respect to REMOTE RESET see Table A 1 The following paragraph provides a brief circuit description see schematic diagram and Figure A 7 A 46 negative going edge at REMOTE TRIP is coupled through opto isolator U5 and sets the Trip Reset latch output low This shuts down the supply by pulling down the OV STATUS INHIBIT line J1 1 which inhibits the Pulse Width Modulator it also lights the OVP indicator on the front panel and results in the generation of an OVERVOLTAGE status signal from opto isolator 01 This signal does not affect the state of the power supply s OVP circuit A 47 Remote Reset A negative going edge applied at input J2 29 REMOTE RESET will return the supply to its in itial state following a system initiated shutdown REMOTE TRIP or an OVP shutdown caused by a temporary over voltage condition For minimum pulse duration and timing considerations with respect to REMOTE TRIP see Table A 1 The following paragraphs provide a brief description of this circuit
133. nsient Recovery Time Definition The time X for output voltage recovery to within millivolts of the nominal output voltage follow ing a Z amp step change in load current where Y is specified as 100mV and Z is the specified load current change of 1096 of maximum current rating 5 31 Measurement Techniques The load must be Switched between two resistance values such that the load current varies 1096 of the maximum current rating at any out put voltage For example if the test is done at 40V output the maximum current available is 30A Therefore the current should vary by 1096 A load increase of 0 149 9 from 1 333 Q to 1 482 0 will decrease output current from 30 A to 27 5 32 The load change need not be at the maximum current available as in the previous example but it should cause a current change of 1096 of the maximum current available Therefore at the same 40V output the load would have to decrease 0 218 Q from 1 818 9 to 1 600 9 to increase output current by 3A from 22A to 25A The maximum current available is different at different output voltages therefore the 1096 value is different for each output voltage The test may be run at whichever output voltage current combination s is are of most interest In all cases however the load must be selected such that the output current is equal to or greater than 5A both before and after the load change 5 33 The electronic load listed in Table 5
134. nsing apply only during constant voltage operation When using remote sensing turn off the power supply before changing the rear panel straps sense leads or load leads The following paragraphs discuss some precautions that should be observed when making a remote sensing installation 240 VOC MAX TO Hs ow 3 39 The load leads should be of the heaviest practicable wire gauge at least heavy enough to limit the voltage drop in each lead to 0 5 volts The power supply has been designed to minimize the effects of long load lead inductance but best results will be obtained by using the shortest load leads practical NOTE Because the OVP circuit monitors voltage at the rear terminals and there is an unavoidable voltage drop in the load leads it may be necessary to readjust the OVP trip point in remote sensing mode 3 40 Since the sensing leads carry only a few milliamperes the wires used for sensing can be much lighter than the load leads AWG 22 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 and CV load regulation may be adversely af fected 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 load as possible 3 41 The sensing leads are part of the supply s program ming circuit so
135. nt mode by checking CC light h Disconnect DVM from power supply sense terminals and reconnect DVM across Rag Record voitage indicated on DVM j Adjust autotransformer for high line voltage k Reading on DVM should not differ from reading of step i by more than 10 aV 5 49 PARD Ripple and Noise Definition The residual ac current superimposed on the dc output of a regulated power supply Ripple and noise measurement may be made at any input ac line voltage com bined with any dc output voltage and load currrent within the supply s rating 5 50 Most of the instructions pertaining to pickup problems associated with constant voltage ripple and noise measurement also apply to the measurement of constant current ripple and noise The current probe listed in Table 5 1 clips on one of the load leads 5 51 To check the ripple and noise proceed as follows 8 Connect test setup shown in Figure 5 7 b Rotate VOLTAGE controi fully clockwise c Turn on supply and adjust CURRENT control and load so that the front panel meters indicate 50 A and 20 V d The observed ripple and noise should be less than 2b mA mms RMS VOLTMETER OR OSCILLOSCOPE POWER SUPPLY CURRENT PROBE AMPLIFIER Figure 5 7 Constant Current Ripple and Noise Measurement Test Setup TROUBLESHOOTING WARNING Maintenance described herein is performed with power supplied to the instrument and protective covers removed Such maintenance should be
136. nvolves more than one function check the output voltages of the Bias Supplies Table A 1 A 76 Troubleshooting Resistance and Voltage Programming a Confirm that problem is on option board by disconnect ing P1 from Control Board and attempting to program the supply via the rear panel terminal strip b Check 15 V and 11 8 V supplies Check for a problem in the Programming Protection cir cuit This circuit should draw about 2 from the pro gramming lines d Check for shorted relay contacts on K 1 and K2 Troubleshooting Current Programming a Check 15 V supplies b Check supply and proceed to the test set up shown in Figure A 10 and or A 11 Disconnect J2 11 and or J2 12 from J2 7 See if varying the voltage source produces 0 to 5 V at K1 pin 14 and or K2 pin 14 If not check op amps and associated circuitry d Return to original test set up and see if varying the voltage source produces 0 to 5 V at K1 pin B and or K2 pin 8 If not check relays for proper operation If relays are okay check for a problem in the Program ming Protection circuit This circuit should draw about 24A from the programming lines 002 OPTION CV CURRENT PROG 71 21 CONTROL ISOLATOR BIAS RELAY K2 Figure A 10 Troubleshooting Current Programming of CV Mode 002 OPTION _ CC CURRENT PROG CONTROL ISOLATOR BIAS 5 RELAY Figure A 11 Troubleshooting Current Programming of
137. of the main board To convert the instrument from one line voltage option to another proceed as follows a Disconnect line cord from power source and wait 120 seconds b Remove top cover from instrument by removing three screws one on each side and one in center that secure cover to rear panel slide cover to rear and lift off C Use a smail biade screwdriver to set the two switch sec tions of S2 to match the pattern silkscreened on main board for nominal line voltage to be used For example to set Switches for 120V operation as illustrated in Figure 2 3 move forward switch section so that its white slot is toward front of instrument and move rearward switch section so its white slot is toward rear of instrument d One end of W1 is soldered to main board the other end has a female quick connect terminal that fits onto one of two terminals soldered to main board For 120V operation W1 must be connected to terminal closer to front of instrument as shown in Figure 2 3 For 220V or 240V operation W1 must be connected to terminal closer to rear of instrument Be certain that jumper is firmly mated with terminal on main board Do not grip jumper insulation with pliers either grip jumper wire by hand or grip jumper terminal with pliers e Jumper W2 is similar to W1 For 120V operation W2 must be connected to terminal closer to rear of instrument as shown in Figure 2 3 For 220V or 240V operation W2 must be connected to terminal
138. office to which the instru ment can be shipped Be sure to attach a tag to the instrument specifying the owner model number full serial number and service required or a brief description of the trouble 2 8 PREPARATION 2 10 In order to be put into service the 6012A must be connected to an appropriate ac input power source Also the line voltage for which the unit is set and the rear panel circuit breaker must be checked Additional steps may include line voltage conversion and rack mounting Do not apply power to the instrument before reading paragraphs 2 15 and 2 17 2 11 Location and Cooling 2 12 The instrument is fan cooled and must be installed 1675 i 425 5 0 40 2 5mm 46 80 __ 426 7 mm 0 70 f i 4 40 TS U7 amm 77 7 07 9mm SIDE Outline Diagram with sufficient space behind the instrument for exhaust it should be used in an area where the ambient temperature does not exceed 50 CAUTION The instrument should not be installed in a forced air cooled rack enclosure in which the static air pressure exceeds 0 06 inches of water Static air pressure behind the instrument of greater than 0 06 inches of water will prevent pro per air flow thorugh the instrument and allow the instrument to overheat 2 13 Outline Diagram 2 14 Figure 2 1 illustrates the outline shape and dimen sions of the cabinet 2 15 Input Power Requirements 2 16 The su
139. om power supply sense terminals and connect DVM across 5 3 Adjust resistance of load until DVM reads 4 mV im dicating that current output is exactly 4 Ensure that power supply remains in constant voltage mode by checking CV light h Disconnect DVM from Ry and reconnect DVM to power supply sense terminais i Record voltage indicated on DVM j Adjust autotransformer for high line voltage Reading on DVM shouid not differ from reading of step i by more than 9 mV 5 20 PARD 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 com bined with any dc output voltage and current within the sup ply s rating 5 21 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 measure ment is particularly important for applications where noise spikes could be detrimental to sensitive loads such as logic cir cuitry The rms measurement is not an ideal representation of the noise because fairly high output noise spikes of short duration can be present in the ripple without appreciably in creasing the rms value RMS VOLTMETER OR OSCILLOSCOPE POWER SUPPLY COAXIAL CABLE OR SHIELOED PAIR Figure 5 3 Constant Voltage Ripple Test Setup 5 22 Ripple Measurement Techniques Figure 5 3 sho
140. onstant voltage operation of the supply POWER SUPPLY DIGITAL VOLTMETER COAXIAL CABLE OR SHIELDED PAIR Figure 5 2 Basic Test Setup 5 15 Rated Voltage and Voltmeter Accuracy To check that the supply will furnish its rated output voltage pro ceed as follows a Connect test setup shown in Figure 5 2 Operate the load in constant resistance mode Amps Voit with resistance initially set to maximum b Turn both CURRENT control and OVP adjust fully clockwise c Turn on supply and adjust VOLTAGE control until digital voltmeter DVM indicates exactly 60V maximum rated out put voltage d Front panel voltmeter should indicate 60V 3 e Disconnect DVM from power supply sense terminals and connect DVM across current monitoring resistor f Reduce resistance of load until DVM reads 17 5 mV in dicating that current output is exactly 17 5A maximum rated power output Ensure that power supply remains in constant voltage mode by checking CV light 9 Disconnect DVM from and reconnect DVM to power supply sense terminals h DVM and front panel voltmeter should both indicate 60V 5 16 Load Effect Load Regulation Definition The change in the static value of dc output voltage AEg T resulting from a change in load resistance from open circuit to a value which yields maximum rated out put current or from the latter value to open circuit 5 17 To check the constant voitage load effect proceed as fol
141. or Ry the equation becomes Rx 50 1000 Rx 12 000 2 25 1000 26 000 3 74 Note that the slave output voltage may be lower than equal to or higher than the master output voltage 3 75 Two factors must be considered when selecting the resistance value of Ry the effect on programming specifica tions particularly speed and the power that the resistor will have to dissipate the previous example with a total resistance of 27k across an output of 90 volts Ry will have to dissipate 290 milliwatts and Ry will have to dissipate slightly more than 11 milliwatts Lower resistance values of Ry and Ry will increase programming speed while increasing the amount of power that Rx and Ry will have to dissipate 3 76 To maintain the temperature coefficient and stability specifications of the supplies and Ry must be stable low noise resistors with temperature coefficients of less than 25 ppm and power ratings of at least 10 times what they will actually dissipate 3 77 Thefront panel VOLTAGE control of the slave can be used in place of Ry by connecting a strap from A7 of the slave to A8 of the slave This enables the user to vary the percent age of the total voltage contributed by the slave For calcula tion purposes use a resistance value of 2 7k for the VOLTAGE control when it is set to maximum 3 78 Overvoltage Protection in Auto Series Set the OVP trip point in each supply so that it
142. ower Supply Programming Card Details are provid ed in the 69520A Manual A 4 Remote Programming Through this interface both the output voltage and current can be remotely programmed by either an external voltage source resistance current sink 8 Status Indicators Six optically isolated lines provide open collector digital outputs which indicate the following states constant voltage mode constant current mode output unregulated AC fault overvoltage and overtemperature 6 Remote Control Two optically isolated methods of remote control are available One method requires a negative going edge which sets a latch on the 002 card to inhibit the power supply The latch and the power supply OVP are reset by a negative going pulse on another input line The second method of remote control requires a low logic level to inhibit the power supply for the duration of the low level 7 Bias Supplies The outputs of three bias supplies are also available at the option connector These outputs are 15 V 15 V 5 V 8 Monitoring of the output voltage and current of the power supply is also possible at the option connector A 9 Other modes of operation such as multiple supply system control are described in detail in later paragraphs Modes such as Auto Series Auto Parallel and Auto Tracking operation as described in Section 3 of the main text are also available A 10 Specifications 11 Table A 1
143. pa aia iae ide en 2 LL seig vo 1 A alae i a rm 212 4 e M vere s s Qi A NRD i i i i ince i aevo aM ey n T uns am a H UN OL T ico snay eus Se 40183100 ApQeQu 27 Wo SR MOD ino AO OL Aem BUMY 22 01 330 AS Svid AS 80493439 HOZ w HIARI Gebr n Tian no 501231301 3981 30 59 034 9 bate Figure 4 2 Simplified Schematic 4 2 the Input Bridge Doubler circuit W1 connects the circuit as a voltage doubler for 120V operation so that for any nominal put voltage the input filter charges to approximately 300Vdc Resistors ATRT1 and ATR3 limit inrush current while the capacitors in the Input Filter charge up after the instrument is turned on After a one second delay provided by the AC Dropout Detector Slow Start Circuit relay ATK1 closes and shorts out 181 and A1R3 4 10 Primary power is also connected to the Bias Power Supplies and the Relay Driver The Bias Power Supplies pro duce the 5V 15V and 12V used throughout t
144. power applied power should be removed Turn power off while con necting or disconnecting test equipment from 60124 20 53 2144 7 5 320kHz CLOCK GATE TO SOURCE OQ Sus DIVISION Oye DIVISION DIVISION 5V DIVISION INPUT BUS AT OV C24 C63 2 2 11 FETS 20 kHz CLOCK DRAIN TO SOURCE fOus DIVISION fOus DIVISION 1V DIVISION 5V DIVISION INPUT BUS AT 20V NO LOAD SEE NOTE 5 C31 t73 209 5 FETS PWM OUTPUT DRAIN TO SOURCE DIVISION 10 us DIVISION 1V 7 DIVISION 5V DIVISION H INPUT BUS AT 20V ide i QUT SHORTED LOAD SEE NOTE 5 4 C87 A2P2 L SENSE ON PULSE A2P2 13 02s DIVISION fOus DIVISION 2V DIVISION 0 4V DIVISION A2P2 40 INPUT BUS AT 20V OFF PULSE OUTPUT SHORTED Ous DIVISION 2V DIVISION VouT RLOAD 500 Figure 7 8 Waveforms APPENDIX System Option 002 A 1 GENERAL INFORMATION A 2 This option facilitates the operation of a 6012A power supply in an automated system Four major circuit blocks pro vide 1 remote analog programming of the supply s output by three different control methods 2 signals indicating the power supply modes and conditions 3 two different digital methods of remote control and 4 the outputs of three bias supplies for use with external circuitry 3 6012A power supply equipped with this option can be operated from 69408 Muitiprogrammer equipped with a 69520A P
145. pply may be operated from a nominal 120V 220V or 240V single phase ac power source 48 63 Hz The in put voltage range and input current required for each of the nominal inputs are listed below Nominal Line Voltage Maximum Voltage Range Input Current 120V 104 127 244 220V 191 233 15A 240V 208 250 14 2 17 Power Connection CAUTION Connection of this instrument to an ac power source should be done only by an electrician or other qualified personnel Before connecting the instrument to the ac power source check the label on the rear panel to ensure that the instru ment is set for the ac voltage to be used necessary the user can convert the instrument from one line voltage option to another by follow ing the instructions in paragraph 2 25 2 18 input power is connected to the instrument via the AC Filter Assembly on the rear panel The power cord must be a three conductor cord rated for at least 85 For 120V operation each conductor must be AWG 12 or larger For 220V or 240V operation each conductor must be AWG 14 or larger Larger wire sizes may be required to prevent excessive voltage drop in the ac input WARNING Do not use three individual wires to connect power to the instrument The strain relief on the rear panel is designed for use only with a single three conductor cord 2 19 To connect input power to the instrument proceed as follows a Remove four screws one in each corner that secure the
146. provides specifications for the Option 002 This table is referred to periodically throughout the Operation section of this Appendix A 12 Option 002 Hardware A 13 The option 002 hardware consists of a single printed circuit board installed at the right of the 6012A chassis A cable connects the option board to the A2 control board at A2J1 Connections between the option board and external cir cuits are made via a 37 pin connector mounted on the option board and available at the rear of the power supply A mating connector is also included for the user s convenience Table A 1 Specifications Option 002 All 6012A specifications remain the same unless otherwise noted All specifications are at option board connector J2 REMOTE PROGRAMMING Resistance Programming 0 to 2 5 Q provides zero to max imum rated voltage or current output Accuracy 25 CV 1 0 30 mV 2 5 35 mA Voltage Programming 0 to 5 V provides zero to maximum rated voltage or current output Accuracy 25 C CV 0 396 3 mV 1 0 15 mA Current Programming 0 to 2 current sink provides zero to maximum rated voltage or current output Accuracy 25 CV 0 4 9 mV 1 1 20 mA Input Compliance Voltage 1 V Current Programming Enable Relays K2 CV and K1 CC are biased from the CONTROL ISOLATOR BIAS input see Remote Shutdown and OVP Clear Relay bias voltage 4 V minimum 7 V maximum Relay resistance 5000
147. ption Troubleshooting can be accomplished by using a logic probe and referring to the schematic and the circuit descrip tions in Section A 46 Before attempting to troubleshoot the Remote Shutdown function of the option check for 5 V at TP1 5 V INT This voltage must be present for proper operation of these circuits A 86 To check REMOTE TRIP and RESET pro ceed as follows a Connect 5 V supply J2 23 to CONTROL ISOLATOR BIAS J2 10 Turn unit on and short REMOTE TRIP J2 30 to power supply common J2 7 momentarily Supply should go into overvoltage condition Short REMOTE RESET J2 29 to common momentari ly Supply should return to initial state b To check REMOTE INHIBIT proceed as follows Connect 5 V supply J2 23 to CONTROL ISOLATOR BIAS J2 10 Turn unit on and short REMOTE INHIBIT J2 31 to power supply common J2 7 Supply should go into overvoltage condition Remove short from J2 31 to common Supply should return to its initial state A 88 Bias Supply Adjustments 89 After troubleshooting and repair of the 002 option it may be necessary to calibrate the Bias Supplies The correct calibration procedures are provided in the following paragraphs Measurements can be taken at the appropriate pins on connector J2 and adjustments are made with the six potentiometers located on the top of the option board A 90 remove the top cover of the power supply remove the four
148. rease total output current capability while main taining control from a single unit Auto Series Up to four units eight if center tapped to ground may be connected in series to increase total output voltage to 240 Vdc 480 Vdc if center tapped to ground while maintaining control from a single unit Auto Tracking Any number of units may have either one of their output terminals connected to a common bus so that outputs track at some fraction the output of a single controlled unit TEMPERATURE RATINGS Operating 0 to 50 C Storage 40 to 75 Unit is fan cooled Thermostats turn off unit if FET or output diode temperatures rise above a critical level reset automatically BACKPRESSURE Unit wil operate against static backpressure at air outlet rear panel of up to 0 06 inches of water air inlet at 0 inches of water CERTIFICATION Unit complies with these requirements IEC 348 Safety Requirements for Electronic Measuring Apparatus CSA Electrical Bulletin 5568 Electronic Instruments and Scientific Apparatus for Special Use and Applications VDE 0871 6 78 Level A Suppression of Radio Frequency Equipment for Industrial Scientific and Medical ISM and Similar Purposes VDE 0411 Electronic Measuring Instruments and Automatic Controls DIMENSIONS See Figure 2 1 WEIGHT Net 15 kg 33 Ib Shipping 16 kg 35 Ib SECTION INSTALLATION 2 1 INITIAL INSPECTION 2 7 REPACKAGING FO
149. ropout Outboard Sense common Overtemperature Status low overtemperature i Monitor Buffer Amplifier Output Constant Current Mode low CC Sense 5 V Unregulated 16 V Overvoltage Status low OVP On Pulses Off Pulses 5 V Regulated 20 kHz Clock Signal not used 15 V Regulated 12 V Regulated Primary Current Ramp Voltage 1 B 2 C 3 D 4 6 H 7 J 8 K 9 L Table 7 2 Semiconductor Components Operating On Each Bias Supply 5 V REG 15V REG 12 V REG A1U2 201 2001 A202 204 A2U2 A2Q3 207 203 205 209 6 5 204 206 201 205 2010 202 206 205 203 207 204 12 V UNREG 208 206 209 2019 14 5 208 2010 2017 2011 i A2U12 15 V UNREG 5 V UNREG 2013 2014 2011 2015 2016 2018 02 7 6 Definitions High more positive Low less positive indicator And Qualifier Symbols polarity indicator shown outside logic symbol Any marked input or output is active low any unmarked input or output is active high gt dynamic indicator Any marked input is edge triggered ie active during transition between states any unmarked input is level sensitive open collector output 1 monostable one shot multivibrator t xSec indicates pulse width usually determined by external RC network G gate input a number following G indicates which inputs are gated
150. s can be obtained p aR A from this supply by grounding of the output terminals It is TOLSA best to avoid grounding the output at any point other than the power suply output terminals to avoid regulation problems LOAD caused by common mode current flowing through the load GROUND CONNECTION TWISTED OR PARALLEL SHOULD BE MADE AND CLOSE TOGETHER leads to ground Always use two wires to connect the load to 6012A NOT AT LOAD the supply regardless of where or how the system is ground ed Never ground the system at more than one point This supply be operated with either output terminal up to 240 volts dc including output voltage from ground Figure 3 2 Connecting a Bypass Capacitor 3 2 3 14 PROTECTIVE CIRCUITS 3 15 Protective circuits within the instrument may limit or turn off the output in case of abnormal conditions The cause for the protective action can be determined by observing the front panel indicators and meters An overrange condition is indicated by the OUTPUT UNREGULATED indicator on all other indicators off and the VOLTS and AMPERES meters reading relatively high An overvoltage condition is indicated by both the OVP and OUTPUT UNREGULATED indicators on all other indicators off and the meters reading near zero An overtemperature condition is indicated by both the OVERTEMPERATURE PROTECTION and OUTPUT UNREGULATED indicators on all other indicators off and the meters dropping tow
151. s possible to convert the Option 100 units to other line voltages by following the direc tions in paragraph 2 25 for 120 V conversion but the unit will maintain its derated 675 W output CAUTION No attempt should be made by the user to uprate the Option 100 unit above its calibrated output voltage and power limits To do so could result in severe damage to the unit and a fire hazard 164 CONSTANT VOLTAGE OPERATING REGIONS gt Rol ocus i F CONSTANT CURRENT 7 OPERATING REGIONS Ri Gap lt Rc isi A lout VOLTAGE CONTROL SETTING CURRENT CONTROL SETTING E CROSSOVER VALUE OF LOAD RESISTANCE Figure B 1 Overall Output Range with Three Sampie Operating Loci Replace Figure 3 4 Table B 1 Specification Changes 6012 Option 100 INPUT POWER Two internal switches and two internal jumpers permit operation from 100 120 220 or 240 Vac 1096 5 48 63 Hz Maximum input current is 24 A rms for 100 and 120 V rms 15 A rms for 220 V rms and 14 A rms for 240 V rms PEAK INRUSH CURRENT Maximum 100 Vac 26 1 A 120 Vac 31 5 A 220 Vac 13 3 A 240 Vac 14 3 A DC OUTPUT Adjustable from 0 to 50 V and 0 to 50 A Maximum output power is 675 W at 50 A 800 W at 50 V and approximately 910 W at midrange See Graph Sov 30V OUTPUT VOLTAGE 40A 5 OUTPUT CURRENT OVERVOLTAGE PROTECTION
152. sary to disable the front panel voltage and current controls during resistance programming This is accomplished at the rear panel terminal strip by disconnecting the jumper between A4 and CURRENT control and the jumper between 8 and A7 VOLTAGE control 22 resistance variable from 0 to 2500 ohms can be used to program the output voltage or current from 0 to full scale To program voltage the variable resistance should be connected from 12 25 CV RES amp VOLT PROG to 42 22 Sense To program current the variable resistance should be connected from J2 24 CC RES amp VOLT to J2 1 outboard sense For setting upper and lower limits refer to paragraphs 3 51 and 3 57 CAUTION if the programming lines become open circuited during resistance programming user s system becomes disconnected from J2 the power sup ply s output will tend to rise above rating supply will not be damaged if this occurs but the user s load may be damaged To protect the load be sure that the overvoltage trip point is properly adjusted and that the CAUTION of paragraph 3 57 is observed A 23 Voltage Control Figure A 4 To program the sup 4 ply with a voltage source it is necessary to disable the front panel control pots and disconnect the supply s internal current sources from the programming voltage nodes This is ac complished at the rear panel terminal strip by disconnecting the jumpers between A8 A7
153. screws that secure the cover to the instru ment Slide the cover back and lift off A 9T 5 V Supply Adjustment The output voltage and current limiting of the 5 V Bias Supply are adjusted as follows a Turn off supply and disconnect all loads b Connect a DVM between J2 23 5 V and J2 7 power supply common Turn on power supply and adjust R43 until DVM reads 5 25 mV Turn off power supply and disconnect DVM Connect 100 5 watt resistor between J2 23 and J2 7 Connect DVM across this resistor Tutn on power supply and adjust R44 until DVM reads 1 7 V 50 mV This limits the output current to 170 Turn off power supply and disconnect DVM resistor A 92 15 V Supply Adjustment The output voltage and current limiting of the 15 V Bias Supply are adjusted as follows a Turn off supply and disconnect ali loads b Connect a DVM between J2 4 15 V and J2 7 power supply common Turn on supply and adjust R45 until DVM reads 15 V i75 mV Turn off power supply and disconnect DVM Connect 500 5 watt resistor between J2 4 and J2 7 Connect DVM across this resistor Turn on supply and adjust R46 until DVM reads 6 25 V t 0 15 V This limits the output current to 125 mA g Turn off supply and disconnect DVM and resistor A 93 15 V Supply Adjustment The output voltage and current limiting of the 15 V Bias Supply are adjusted as follows a Turn off supply and disconnect all
154. should be a positive going ramp starting from 0 volts Otherwise check 2 88 A2R87 2 32 A2R84 A2R55 and 2 31 As the dc level at A2U5 2 varies between 0 and 1 5 volts the pulse width at A2U9 5 should vary from 1 to 20us The ramp magnitude at A2U5 3 also varies proportionally 4 A2U3 output interfaces with down programmer through AZVR7 and A2CR28 Check that A2U6 5 is not loaded down Table 5 3 Troubleshooting Continued CC Circuit 1 Voltage from to A5 should vary from 0 to 5 volts as CURRENT control is varied from minimum to maximum Other wise check CURRENT control and output of constant current source A204 2 Trace signal through A2U6C Amplifier output pin 8 should be high when non inverting input pin 10 is more positive than inverting input pin 9 3 Same as step 3 in CV Circuit 4 ABU2 output pin 6 should vary from 0 to 5 volts as 6012A output current varies from 0 to 50A Otherwise check 202 and associated components inciuding adjustment potentiometers A2R22 and A2R23 5 206 output pin 1 should always be high 15V during normal operation output current 52A A2UGA non inverting input 3 should always be 5 5V 6 A2U18 output 7 should be within or 100mV at dc A2UTA output 1 should be within or 1 5V at dc This dc level should not affect the dc level at A2UGC 9 otherwise check A2C3 and A2R7 user injects a sinusoid
155. simultaneously by the voltage and current controls of the master supply The master supply must always be the one at the positive end of the series combination Any point of the output be grounded if desired as long as no other point in the output is more than 240 volts including output voltage from ground 3 69 The output voltage of each slave supply varies in direct proportion to that of the master The ratio of each slave s output voltage to the master s is established by the ratio of the resistors in the voltage divider connected between the Sense of the master and the 5 Sense of the slave 3 70 Any power supply capable of auto series operation can be used in the auto series combination The supply with the lowest current rating limits the maximum output current of the combination Any well regulated variable output supply can be used as the master 3 71 in applications in which coordinated positive and negative voltages are required center tapping the supply com bination and load as shown in Figure 3 16 allows simultaneous proportional control of both supply voltages If more than four supplies are connected together in an auto ser es combination be certain that neither the more positive end nor the negative end of the auto series combination is more than 240 volts including output voltage from ground 3 72 Setting the Voltage and Current Controls auto series combination of supplies behaves as i
156. sistance must be approximately 3 4 Q to permit operation at 17 5A its maximum output power rating voltage of 60V The power rating of the load must be at least equal to the maximum out put power of the supply 1200 watts 5 10 For load regulation and load transient response tests load resistance must be switched between two values An electronic load such as listed in Table 5 1 eliminates the need for connecting many resistors or rheostats in parallel to pro vide adequate power capability is considerably more stable than carbon pile devices and permits varying the load with an external modulating signal 5 11 Connecting a Current Monitoring Resistor To allow precise measurement of output current a current monitoring resistor such as the shunt listed in Table 5 1 is in serted between the output of the power supply and the load This resistor must be connected as a four terminal device in the same manner as a meter shunt would be see Figure 5 1 The load current is fed to the extremes of the wire leading to the resistor while the monitoring terminals are located as close as possible to the resistance element itself A current monitoring resistor should have tow noise a low temperature coefficient less than 30ppm C and should be used at no more than 596 of its rated power so that its temperature rise will be minimized 5 12 Constant Voltage Tests 5 13 Connect all of the measuring devices used in the constant voltage
157. sons refer to Figure 5 11 Slow Start Procedure CAUTION To prevent excessive inrush current do not manually operate relay on main board b Check that straps on the rear panel terminal strip are properly connected c Check that all connections to the power supply are secure and that circuits between the supply and external devices are not interrupted 5 59 Troubleshooting Test Setup Before continuing with troubleshooting proceed as follows a Turn off supply and disconnect all loads CHECK BIAS VOLTAGES LISTED IN TABLE 5 2 BIAS NO VOLTAGES VOLTAGE NO LIGHT YES ADJUST QUIPUT TO 30V TURN CURRENT CONTROL FULLY CCW OUTPUT VOL TAGE DECREASED NO YES YES DISCONNECT LOAD ADJUST CURRENT CONTROL TO MID RANGE TURN OVP ADJUST SINGLE TURN CCW YES UNREGULATED NO us ON ROTE 4 GF FAILURE 15 ACCOMPANIED BY SMOKE AND OR NOISE GO TO SLOW START PROCEDURE REGARDLESS OF WHETHER CBt 15 TRIPPED 2 NUMBERS IN BRACKETS 2 REPRESENT WAVEFORMS IN FIGURE 1 8 50 TO FIGURE 5 44 SLOW START GO TO FIGURE 5 9 9145 SUPPLIES CHECK FUSE SETTING OF SWITCHES MSZA 8 AIS2B JUMPERS ATW AND REPLACE AIFI iF BLOWN NO TRACE POWER TO FAN FAN OPERATES YES AK CLOSES TISEC AFTER WITH POWER SUPPLY OFF UNPLUG AND CAREFULLY RE PLUG CONTROL BOARD YES 50 TO FIGURE
158. strument Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the instrument Hewlett Packard Company assumes no liability for the customer s failure to comply with these re quirements GROUND THE INSTRUMENT To minimize shock hazard the instrument chassis and cabinet must be connected to an electrical ground The instrument must be connected to ac power through a three conductor power cable with the third wire firmly connected to an electrical ground safety ground at the power outlet DO NOT OPERATE IN AN EXLOSIVE ATMOSPHERE Do not operate the instrument in the presence of flammable gases or fumes Operation of any electrical instrument in such an environment constitutes a definite safety hazard KEEP AWAY FROM LIVE CIRCUITS Operating personnel must not remove instrument covers Component replacement and internal ad justments must be made by qualified maintenance personnel Do not replace components with power cable connected Under certain conditions dangerous voltages may exist even with the power cable removed To avoid injuries always disconnect power discharge circuits and remove floating voltages before touching components DO NOT SERVICE OR ADJUST ALONE Do not attempt internal service or adjustment unless another person capable of rendering f rst aid and resuscitation is present SAFETY SYMBOLS N Caution
159. supply back on and set desired output voltage 3 34 Resetting the OVP Circuit if the OVP circuit trips during normal operation the ac LINE switch must be turned Off for at least two seconds and then back to reset the cir cuit If the OVP circuit trips continuously check the load and or the trip point setting If the supply does not operate properly after the circuit is reset proceed to troubleshooting in Section V 3 35 ALTERNATE OPERATING MODES 3 36 The alternate operating modes discussed in the following paragraphs include remote voltage sensing remote programming auto parallel operation auto series operation and auto tracking operation By changing the rear panel strapping pattern according to the instructions which follow the supply can be operated in any of the modes listed above WARNING Disconnect input ac power before changing rear panel connections and make certain all wires and straps are properly connected and terminal strip screws are securely tightened before reapplying power 3 37 Remote Voitage Sensing 3 38 Because of the unavoidable voltage drop developed in the load leads the normal strapping pattern shown in Figure 3 3 will not provide the best possible voltage regulation at the load The remote sensing connections shown in Figure 3 5 im prove the voltage regulation at the load by monitoring the voltage there instead of at the supply s output terminals The advantages of remote se
160. symbol Advises the operator to refer to the instruction manual for additional information D indicates terminal intended to be connected to system ground DO NOT SUBSTITUTE PARTS OR MODIFY INSTRUMENT Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the instrument Return the instrument to a Hewlett Packard Sales and Service Office for service and repair to ensure that safety features are maintained DO NOT EXCEED INPUT RATINGS This instrument is equipped with a line filter to reduce electromagnetic in terference and must be connected to a properly grounded receptacle to minimize electric shock hazard Operation at line voltages or frequencies in excess of those stated on the data plate may cause leakage currents in ex cess of 3 5 mA Section TABLE OF CONTENTS Page GENERAL INFORMAT ON 11 DESCRIPTION 1 1 18 SAFETY CONSIDERATIONS 1 1 1 10 SPECIFICATIONS 1 1 1 12 INSTRUMENT AND MANUAL IDENTIFICATION 1 1 1 15 OPTIONS 1 1 1 7 ACCESSORIES 1 2 1 19 ORDERING ADDITIONAL MANUALS 1 2 INSTALLATION 2 1 INITIALINSPECTION 2 1 2 3 Mechanical Check 2 1 2 5 REPACKAGING FOR SHIPMENT 2 1 2 9 2 1 2 11 Location and Cooling 2 1 2 13 Outline Diagram 2 2 2 15 Input
161. t Packard Sales Office 3 19 NORMAL OPERATING MODE 3 20 The power supply was shipped with the proper rear panel strapping connections made for constant voltage constant current operation with local sensing and local programming This strapping pattern is illustrated Figure 3 3 By means of the front panel voltage and current controls the operator selects either a constant voltage or a constant current output as described in Paragraphs 3 27 or 3 29 Whether the supply functions in the constant voltage or constant current mode depends on the settings of the VOLTAGE and CURRENT controis and on the value of the load resistance 3 3 240 VOC TO rh Figure 3 3 Normal Strapping 3 21 Figure 3 4 shows the overall output range of the sup ply with three sample operating loci Locus 1 is established with a VOLTAGE setting of 20V and a CURRENT setting of 8A For any values of load resistance greater than the crossover value of 2 5 ohms the supply operates in constant voltage mode For values of load resistance less than the crossover value the supply operates in constant current mode The transition occurs smoothly and automatically no switches need be operated or connections changed The front panel VOLTAGE and CURRENT lights indicate which mode is operating CONSTANT VOLTAGE OPERATING REGIONS gt Rc OPERATING REGIONS oap lt Re a i i i i
162. t current output is exactly 50A d Disconnect DVM from and connect DVM to power supply sense terminais Adjust resistance of load until DVM indicates 20V En sure that power supply remains in constant current mode by checking CC light f Disconnect DVM from power supply sense terminals and reconnect DVM to Ry g Record voltage indicated on DVM h Short circuit load Electronic load listed in Table 5 1 has short circuit switch i Wait a few seconds only to allow DVM to settle Reading on DVM should not differ from reading of step g by more than 10 aV 5 47 Source Effect Line Regulation Definition The change in the static value of dc output current Algur resulting from change in ac input voltage over the specified range from low line to high line or from high line to low line 5 48 check source effect proceed as follows a Connect test setup shown in Figure 5 2 b Connect variable autotransformer between input power source and power supply ac power input c Adjust autotransformer for iow line voltage Paragraph 2 15 d Turn VOLTAGE control fully clockwise e Turn on power supply and adjust CURRENT control until DVM reads 50 mV indicating that current output is exactly 50A maximum rated output current f Disconnect DVM from and connect DVM to power supply sense terminals Adjust resistance of load until DVM reads exactly En sure that power supply remains in constant curre
163. t 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 measur ment interval than during the half hour warm up period 5 41 To check the output stability proceed as follows a Connect load and digital voltmeter DVM as illustrated in Figure 5 2 b Turn CURRENT control fully clockwise Turn on supply and adjust VOLTAGE control until DVM indicates exactly 60V maximum rated output voltage d Disconnect DVM from power supply sense terminals and connect DVM across current monitoring resistor e Reduce resistance of load until DVM reads 17 5 mV in dicating that current output is exactly 17 5A maximum rated power output Ensure that power supply remains in constant voltage mode by checking CV light f Disconect DVM from and reconnect DVM to power supply sense terminals g Allow 30 minutes warm up then record DVM reading h After eight hours DVM reading should not differ from reading of step g by more than 23 mVdc 5 42 Constant Current Tests 5 43 instruments methods and precautions for the proper rneasurement of constant current power supply characteristics are for the most part identical to those already described for the measurement of constant voltage characteristics The main difference is that the power supply performance will be checked between short circuit and full load rather than open cir
164. ted circuit board c FETs plug into pins that are soldered to printed circuit board Do not unsolder these pins Carefully unplug each FET CAUTION To avoid damage to FETs handle with care when out of circuit Use a grounding strap to avoid static discharge into gate Avoid touching gate or source pins FETs should be replaced pairs if one FET on a FET board has to be replaced replace both NOTE When replacing FETs or thermostat you must spread a thin layer of heatsink compound be tween component and heatsink See note follow ing Paragraph 5 68 step g for recommended com pound d Before re assembly of FET board ensure that plastic insulators for FET leads remain in heatsink Figure 5 13 shows component mounting e Ensure that four pins for FET leads are standing straight up from printed circuit board f Mate printed circuit board with heatsink ensuring that four FET lead pins fit into four holes in heatsink g Carefully mate FET leads with pins extending into heatsink from printed circuit board h Replace four screws that secure FETs and heatsink to printed circuit i Re solder wires to thermostat SCREWS W LOCKWASHERS TO3 COMPONENT ES T i t t t T en wn HEATSINK W PLASTIC 11 INSULATOR INSERTS a FR 103 COMPONENT LEAD PINS PHINTED CIRCUIT BOARD W STANDOFFS 1 Figure 5 13 Components A301 A3Q2 A4Q1 Mounting 5 73 Output Dio
165. test set up connect top end of 2 kQ resistor to J2 16 e Connect a SPST switch across any one of the three thermostats in the 6012A One thermostat is mounted on each of the three heatsink assemblies The ther mostat on the Output Diode assembly mounted A13 furthest to the right is the most accessible Ensure that all three heatsink assemblies are standing straight up and not touching one another or any part of the 6012A chassis Reconnect 6012 line cord andturn unit on WARNING The FET heatsinks are connected to the 6012 primary circuit and hazardous voltages up to between 300 V and 400 V dc exist between each of the heatsinks and between the heatsinks the 6012 chassis These potentials remain for up to two minutes after the 6012A is turned off Do not touch the heatsinks or any components on the heatsink assemblies while the 6012A is turned on or for at least two minutes after primary power is turned off Do not place any of the heatsink assemblies on extender boards With SPST switch open DV volts Close SPST switch DVM should read Oto 4 V Turn off power supply and disconnect line cord Wait at least two minutes for input capacitors to discharge and disconnect SPST switch from ther mostat 1 Replace heatsink cover top cover and reconnect line cord M should read about 5 85 Troubleshooting Remote Shutdown The follow ing procedures check the Remote Shutdown features of the o
166. the instru ment or software or firmware will be uninterrupted or error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmen tai specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRAN TIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HP SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY ASSISTANCE Product maintenance agreements and other customer assistance agreements are available for Hewlett Packard pra ducts For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual a AUTORANGING DC POWER SUPPLY MODEL 6012A OPERATING AND SERVICE MANUAL FOR SERIALS 1946A 00101 AND ABOVE For Serials above 1946A 00101 a change page may be included Part No 06012 30001 Printed August 1980 SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation service and repair of this in
167. they should be connected in such a way as to make it unlikely that they might inadvertently become open circuited If the sense leads open during operation it is possi ble that the load voltage will rise above its programmed value Therefore it is recommended that no switch relay or connec tor contacts be included in the remote sensing path 3 42 Remote Programming 3 43 The output voltage and or current of the power sup ply can be remotely controlled by external resistance voltage or current sink Programming can be accomplished via the standard rear panel screw on terminals or v a the option con nector on units equipped with System Option 002 Standard programming is described in this section programming with System Option 002 is described in Appendix A 3 44 For resistance programming a variable resistor can control the output over its entire range To restrict control of the variable resistor to a limited portion of the output range fixed resistors can be connected in series and or parallel with the variable resistor Alternatively a switch can be used to select fixed values of programming resistance to obtain a set of discrete voltages or currents It is recommended that make before break switch contacts be used to avoid pro ducing the output voltage spikes caused by momentarily opening the programming terminals The output voltage will drop momentarily while both sets of switch contacts are closed break before make s
168. time when the Control Voltage is exceeded at A2U5 and the time when the FETs turn off This delay consists of the com parator switching time gate delays transformer delay and FET turn off time and it results in a certain amount of power being transferred to the output after the desired off time if the Control Voltage is at a very low level unit supplying little or no output power this power may exceed the amount required by the load offset this the PWM is designed to reduce the minimum on time of the FETs if necessary to reduce the power transferred to the output circuit When the 20 kHz Ciock goes high allowing the PWM to be triggered by the next 320 kHz signal A2C31 charges rapidly and exponentially ON PULSE A2U9B CLOCK INPUT 320kHz CONTROL INITIATES OFF PULSE VOLTAGE ee A RAMP VOLTAGE 205 LA COMPARATOR i OUTPUT E i ON PULSE OFF PULSE u ON je EET TURN OFF DELAY FETS Opp eM 227 Figure 4 3 FET Control Signais Timing Diagram 4 4 to low level this auxilary ramp level exceeds the Control Voltage the PWM initiates an off pulse turning off the FETs immediately after they turn on 4 32 Primary Current Ip Limit 4 33 Ramp Voltage is also compared to a preset Limit at comparison amplifier A2U13D Ip Limit is a factory set ad justment that limits the total power output of the instrument Ordinarily the PWM init
169. to interface the user s system with the option connector J2 Figure A 1 identifies the parts of the mating connector Proceed as follows Figure A 1 Mating Connector Assembly NOTE may be desireable to set up a test interface before final assembly of the mating connector to allow checkout of the system mating connec tor with pins accessible for temporary wiring is available from Hewlett Packard HP part number 1251 4464 a If a multi wire cable is being used as opposed to jn dividual wires remove approximately 1 72 inches of cable insulation from the end Be careful not to cut the insulation on the individual wires b Strip 3 16 inch of insulation from end of each wire to be used c Insert each wire into a contact pin 1 and crimp firmly d insert each pin into proper hole in connector pin house 2 from rear Pins will lock into housing when fully in 5 Once the pins locked into the connector pin housing they are extremely difficult to remove Therefore be certain pin is in proper hole before inserting fully e Screw a slotted set screw 3 partially into a square nut 4 and place in position in connector shield assembly 6 f Place strain relief 5 in position in connector shield assembly 6 just under set screw 3 Be certain that strain relief is oriented as shown in Figure 1 g Place connector pin housing 2 in shield assembly 6 and route cable throug
170. tors A2R59 R63 The amplitude of this linearly increasing voltage corresponds to the amount of current flow through the AT1T2 primary therefore it represents the amount of energy being stored in the field around A172 It is this Ramp Voltage that is compared to a control voltage to determine when the FETs should be turned off 4 14 Off pulses for the FETs are applied through driver 18 and transformer to the base of transistor A3Q3 A3Q3 turns on and shorts the FETs gates to sources thereby turning the FETs off When the FETs turn off the collapsing magnetic field reverses the polarity across the A1T2 primary and current flows from A1T2 secondary through Output Diode A4CR1 to charge output capacitors 1 11 1 12 and A1C21 The level to which the output capacitors are charged corresponds to the length of time that the FETs are on and current flows in A1T2 primary 4 3 4 15 When the FETs turn off the leakage inductance of A1T2 develops a small amount of reverse current flow in the primary circuit Flyback Diodes ATCR3 and 1 4 protect the FETs by conducting this current around the FETs and back to the Input Filter Voltage spikes are filtered by the Snubber networks 4 16 can be seen that the power available in the ouput circuit corresponds to the duty cycle of the FET switches The following paragraphs describe the method by which output voltage and current are sensed to control the FET duty cycle
171. trips at a level higher than the voltage that supply will contribute If the master sup ply OVP trips the master will program the slaves to zero out put If a slave OVP trips that slave and all slaves between it and the negative end of the series will go to zero ouput all units more positive than the tripped slave which includes the master will continue to supply their set output voltage Therefore the total output voltage of the auto series com bination will be the sum of the outputs from the master plus any slaves between the master and the tripped slave 3 79 For maximum protection against overvoltage set each unit s OVP slightly higher 1 5 volts 1 than the voltage it will contribute For maximum protection against faise tripping set the slave OVPs to maximum and adjust OVP at the master 3 80 Auto Series with Remote Sensing To combine auto series operation with remote sensing connect the sup plies as described above but remove the S jumper from the master supply and the 5 jumper from the most negative supply and connect the S and the S terminals directly to the and ends of the load 3 81 The output voltage and or current of an auto series combination can be remotely programmed Remote program ming connections are made to the master supply The percentage of the total voltage contributed by a slave can also be remotely programmed by connecting a variable resistor to the slave in place of Ry Observ
172. ude two that secure 1 to the main board four that secure T2 to the main board and two that secure T3 to the main board To remove the main board proceed as follows NOTE Certa n components can be accessed through bottom chassis without removing main board See Paragraph 5 79 Relay K1 can be removed to allow access to components under K1 without removing main board See Paragraph 5 77 a Remove control board both FET board assemblies and output diode board assembly b Remove red and black wires from output bus bars c Remove and tag any wires connected to board from components not on main board Note that this step is re quired only if main board is to be completely removed from unit Main board can be pulled up and turned on its side without removing any wires d Remove 16 mounting screws see Figure 7 1 for locations Lift board up inch so capacitor bracket clears spacers under four large filter capacitors and tilt board to allow access to bottom of board 5 77 Relay K1 Removal 5 78 Resistors R1 R2 and R3 are mounted under relay K1 on main board To remove K1 proceed as follows a Remove and tag six wires connected to K1 from main board Figure 7 1 shows wire colors and locations b Remove two screws that secure K1 to main board Figure 7 1 shows screw locations 5 79 Component Access Through Bottom Chassis 7754 5 2026 6 c 4 2
173. unit should have been turned on for at least 30 Figure 5 15 Location of Adjustment Potentiometers minutes before performing any adjustments to allow it to reach normal operating temperature 5 90 Meter Zero Adjustment 5 91 The meter pointers must point to zero on the meter scales when the instrument is at normal operating temperature in its normal operating position and turned off The same pro cedure is used for both meters To zero a meter proceed as follows a Turn power supply off and wait three minutes for The power supply should be turned off while making and removing connections to the rear panel terminals A2R20 Limit Table 5 4 Adiustments Sympton indicating Adjustment Necessary Output unregulated even though operating within power limit set too low or provides more than 25V at 50A set too high 0 volt programming input does not produce 0 output A2R21 CV Offset A2R22 Full Scale A2R23 Offset A2R24 Constant Current Source A2R130 Ammeter Adjust 5 volt programming input does not produce 50 amp output 0 programming input does not produce 0 output 2 5k resistive programming input does not produce 60 volt output Front panel ammeter does not agree with output current indicated by DVM connected across shunt in series with output A2R131 Voltmeter Adjust Front panel voltmeter does not agree with DVM conn
174. ust A2R 130 for 50 A reading on front panel ammeter e Turn off power supply and disconnect shunt 5 102 Voitmeter Adjustment 5 103 The CV offset and constant current source adjust ments should be correct before adjusting the voltmeter circuit To adjust the voltmeter circuit proceed as follows a Connect digital voltmeter DVM across output ter b Turn on power supply and adjust VOLTAGE control for 60 V 120 mVreading on DVM Adjust A2R131 for 60 V reading on front panel voltmeter SECTION VI REPLACEABLE PARTS 6 1 INTRODUCTION 6 2 This section contains information for ordering replace ment parts Table 6 4 lists parts in alpha numeric order by reference designators and provides the following information a Reference Designators Refer to Table 6 1 b Hewlett Packard Part Number c Total Quantity TQ used in that assembly d Description Refer to Table 6 2 for abbreviations e Manufacturer s Federal Supply Code Number Refer to Table 6 3 for manufacturer s name and address f Manufacturer s Part Number or Type 6 3 Parts not identified by 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 in dividual assemblies the latter consists of all parts not im mediately associated with an assembly Table 6 1 Reference Designators Assembly Blower fan Capacitor Circuit Breaker Diode Signa
175. utes for capacitors to discharge before making resistance checks or removing components in primary circuit 3 Unless otherwise noted all voltages measured with respect to bias common available at A2U15 case 4 Numbers in brackets refer to waveforms shown in Figure 7 8 5 The troubleshooting trees and table provide general guidelines to help isolate trouble They will not isolate possible troubles The user should use signal tracing and other standard troubleshooting techniques to identify faulty com ponents The user is responsible for connecting and adjusting meters oscilloscopes etc properly 6 Before replacing a component check connections to the component and ensure that bias voltages to the compo nent are correct 7 After isolating and correcting a problem go back to beginning of troubleshooting tree 6012A POWER SUPPLY WITH REMOVED VARIABLE AUTOTRANSFORMER OW min ISOLATION TRANSFORMER min Figure 5 10 Slow Start Setup Table 5 2 Bias Voltage Check Normai Range Measurement Point Bias Voltage 15V Reg 12V Reg 4 75V to 5 25 14 10V to 15 90V 12 96V to 11 04V Check These Components Check for presence of 5V Unreg 12V 19V if absent check A113 pins 8 and 10 A1CR7 8 A1C14 ATR18 ATVR2 If present check A2U15 Check for presence of 15V Unreg 19V to 31V pin D If absent check A1T3 pins 7 and 11 A1U4 A1C1
176. uto paralleled supply to the load Load sharing will not be equal unless the leads connec ting each supply to the load are equal resistance lf it is impractical to run leads from each supply to the load because of distance be tween the supplies and the load leads of equal length should be run from each supply to com mon distribution terminals with a single pair of leads run from the distribution terminals to the load MASTER 3 66 Auto Parallel with Remote Programming The output voltage and or current of an auto parallel combination can be remotely programmed Remote programming connec tions are made to the master supply Observe all precautions outlined in the remote programming paragraphs Simultaneous use of remote sensing and remote programming is also possible during auto parallel operation NOTE Because only the master can down program the output of an auto parallel combination down 25930 programming speed will be reduced under load conditions 3 67 Auto Series Operation YO pe P i Bead vec 4 MAX 2 pui Figure 3 14 Auto Parallel Operation 3 63 Setting the Voltage and Current Controls The auto parallel combination of supplies behaves as if it were single constant voltage constant current supply controlled by the voltage and current controls of the master supply The current controls of the slaves are disabled The voltage con trols of th
177. utput Voltage programming time An equivalent resistance of less than 1k will make the degradation unnoticeable in most applications ff the programming terminals A7 to S become open circuited during resistance programming the output voltage will tend to rise above rating The supply will not be damaged if this occurs but the OVP trip point should be properly adjusted to protect the user s load 240 VOC TO Hy X 3 53 Voltage Programming of Output Voltage rear panel connections shown in Figure 3 7 allows the output voltage to be varied by using an external voltage source to pro gram the supply A voltage source variable from 0 to 5 volts produces a proportional output voltage from zero to full scale The load on the programming source is less than 5 240 VDC MAX VOLTAGE SOURCE 5V Figure 3 8 Scaled Voltage Programming of Output Voltage 3 56 Current Programming of Output Voltage The rear panel connections shown in Figure 3 9 allow the output voltage to be varied by using an external current sink to pro gram the supply in this configuration the supply s own con stant current source is used to develop a voltage across the resistor A current sink such as a DAC connected in parallel with the resistor sinks part or all of the current and thereby determines the voltage developed across the resistor See VOLTAGE note following Paragraph 3 47
178. wing connection drawings Figures 3 6 through 3 13 show the supply strapped for local sensing remote programming and remote voltage sensing do not in teract and may be used simultaneously 3 51 Resistance Programming of Output Voltage The rear panel connections shown in Figure 3 6 allow the out put voltage to be varied by using an external resistor to pro gram the supply programming resistor variable from 0 to 2500 ohms produces a proportional output voltage from zero to full scale Note that fixed resistors may be connected in series and or parallel with the variable programming resistor to set lower and or upper output voltage limits The resultant programming resistance is the sum of the series parallel resistor combination and must be between 0 and 2500 ohms 3 52 For example a 1250 ohm resistor connected in series with the variable programming resistor will set the lower limit for output voltage at one haif full scale 30 volts A 1250 ohm resistor connected in parallel with a 2500 ohm variable programming resistor will set the upper limit for output voltage at 20 volts Connecting the parallel resistor directly from ter minal A7 to S will limit the output voltage even if the remote programming leads become open circuited 240 VOC OPTIONAL SETS UPPER LIMIT 1 1 PROGRAMMING OPTIONAL RESISTOR SETS LOWER 2 5K LIMET Figure 3 6 Resistance Programming of O
179. witch contacts are used the output voltage will rise momentarily while both sets of switch contacts are open Depending on the switching speed this may trip the OVP 3 45 To maintain the temperature and stability specifica tions of the supply any resistors used for programming must be stable low noise resistors with a temperature coefficient of less than 25 per and a power rating at least 10 times what they will actually dissipate 3 46 Both voltage and current outputs can also be con trolled by a voltage source voltage source of 0 to 5 volts programs the output from zero to full scale Voltage sources of more than 5 volts can be scaled down to the proper range 3 47 Current programming of both voltage and current outputs is possible also With current programming the sup ply s own constant current sources are used to provide current through an external resistance controllable current sink such as a DAC in parallel with the external resistor sinks controllable percentage of the current around the resistance The remaining current flows through the external resistance and develops a voltage that programs the power supply The DAC used for current programming must be capable of sink ing 0 2 mA and must a compliance voltage range of 0 to 6012 constant current source must be calibrated to provide exactly 2 mA and the DAC must sink exactly 2 mA when it is programmed for
180. ws the method for measuring ripple using a single ended true reading RMS voitmeter or oscilloscope The power sup ply output terminals should not be connected to ground at the power supply terminal strip to prevent current from flowing through a ground loop and adding to the measured signal gt Also to ensure that no potential difference exists between the supply and the RMS voltmeter it is recommended that they both be plugged into the same ac power bus If the same bus cannot be used both ac grounds rnust be at earth ground potential 5 23 To minimize pickup a coaxial cable or shielded two wire cable should be used to connect the sensing terminals of the power supply to the input of the RMS voltmeter To verify that the RMS voltmeter is not measuring ripple that is induced in the leads or picked up from ground turn both the VOLTAGE and CURRENT controis fully counterclockwise and short the voltmeter lead to the voltmeter lead at the power supply output terminals If the test setup is properly configured the noise value obtained when the leads are shorted should not be significant compared to the measured ripple value 5 24 Ripple Measurement Procedure To check the rip ple output proceed as follows a Connect test setup shown in Figure 5 3 b Tum CURRENT control fully clockwise C Turn on power supply and adjust VOLTAGE control and load so that front panel meters indicate 40V and 30A d Ripple should be less than 5 m

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