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HP 6213A User's Manual

1. bi DC POWER SUPPLY BENCH SERIES MODEL 6213A OPERATING AND SERVICE MANUAL FOR SERIALS 8F0101 0150 For Serials Above 7F0150 Check for inclusion of change page 100 Locust Avenue Berkeley Heights New Jersey 07922 HP Part No 06213 90001 Printed May 1968 Section I GENERAL INFORMATION LI IH IV 1 1 miu 5 7 g l 1 1 4 1 3 2 15 2 17 2 19 2 22 INS 2 1 2 3 2 5 2 7 2 9 21 2 1 TABLE OF CONTENTS Page No Description Specifications Options Accessories Instrument Manual Identification Ordering Additional Manuals NSTALLATION Initial Inspection Mechanical Check Electrical Check Installation Data Location Outline Diagram Rack Mounting Input Power Requirements Connections for 230V Operation Power Cable Repackaging For Shipment OPERATING INSTRUCTIONS Turn On Checkout Procedure Operation Constant Voltage Changing Current Limit Connecting Load Operation of Supply Beyond Rated Output Optional Operating Modes Series Operation Parallel Operation Special Operating Considerations Pulse Loading Output Gapacitance Reverse Current Loading PRINCIPLES OF OPERATION 4 1 4 5 Simplified Discussion Detailed Circuit Analysis yu l l l le 1 i EE i FEE a NNN HEE ee eee i 9 DO DO DO DO N N DO N N DW 1 Ree Eee ii Section Page No IV PRINCIPLES OF OPERATION CONTINUED 4
2. 3101 Power Transformer obd 9100 2200 Zener 12 4V 5 400mW 1N963B 1902 3185 Zener 4 22V 5 400mW 1N749 1902 3070 Zener 6 2V 5 400mW 100ppm 1N821 1902 0761 ener 12 4V 5 400mW 1N963B 1902 3185 NOT ASSIGNED Zener 6 2V 5 400mW 100ppm 1N821 1902 0761 Zener 6 19V 5 400mW 1N753 1902 0049 MISCELLANEOUS P C Board Main Includes Com ponents 06213 60020 Printed Circuit Board Main Blank obd 5020 5722 P C Board Front Panel Includes Components obd 06213 60021 Printed Circuit Board Front Panel Blank Meter Board Heat Sink 5 Way Binding Post Black 5 Way Binding Post Marcon Cap Rear Cover Top Cover Bottom Front Panel Assembly Meter 24 Scale Dual Scale 0 12V 0 1 2A Bezel Meter 1 6 Mod Spring Meter Line Cord Strain Relief Bush Line Cord Fuseholder Neoprene Washer Fuseholder Nut Fuseholder Lockwasher Fuseholder Insulator Mica Q7 Insulator Transistor Pin Q7 Insulator Transistor Screw Q7 Knob Black Fastener DS1 obd 5020 5723 obd 5060 6141 DF21C 1516 0039 obd 1510 0040 obd 4040 0052 obd 4040 0050 obd 4040 0051 obd 06213 60001 mi ee et O e obd 1120 1133 obd 4040 0295 obd 1460 0256 KH 4096 8120 0050 SR 5P 1 0400 0013 342014 1400 0084 901 2 1400 0090 903 12 2950 0038 1224 08 2190 0037 734 0340 0174 obd 0340 0166 obd 0340 0168 obd 0370 0084 C17373 012 24B 0510 0123 PNDNHE EHEHEHEH A 6213A 6 6 SECTION VII CIRCUIT DIAGRAMS This section
3. 5 11 Troubleshooting 5 10 5 7 Calibration Adjustment Summary 5 13 LIST OF ILLUSTRATIONS Figure Page No Figure Page No l DC Power Supply lv 5 3 Differential Voltmeter Substitute m Outline Diagram 2 1 Test Setup m t i Rack Kit with Three BENCH Supplies 2 1 Input Power Transformer Connections 2 2 Front Panel Controls and Indicators 3 1 Simplified Schematic 4 1 Front Panel Terminal Connections 5 1 Output Current Measurement Technique 5 1 t Output Current Test Setup Load Regulation Test Setup Ripple and Noise Test Setup Noise Spike Test Setup Output Impedance Test Setup Transient Recovery Time Test Setup Transient Recovery Time Waveforms Servicing Printed Wiring Boards I i i U 1 i f 1 t Aw Pwr N Ne NE MEC DL a A A Ut GA vi vi i m mm DQ NO W moO m GM 01 Gr GA ui A G1 Li eHORMOOORRZOW 1 iii a as noch Suwon Z i oe i Figure 1 1 DC Power Supply iv SECTION I GENERAL INFORMATION 1 1 DESCRIPTION 1 2 This power supply Figure 1 1 is completely transistorized and suitable for either bench or relay rack operation It is a compact regulated Con stant Voltage Current Limiting supply The output voltage can be continuously adjusted throughout the output voltage range The power supply is fully pro tected from overloads by a fixed current limit which is set by means of an internal adjustment The cur rent limit circuit pe
4. 6 4 11 4 13 4 17 4 20 4 22 4 26 Feedback Loop Series Regulator Constant Voltage Input Circuit Driver and Error Amplifier Current Limiting Circuit Reference Circuit Meter Circuit V MAINTENANCE 5 1 5 3 5 6 5 11 5 13 5 15 5 18 5 20 5 35 5 38 5 40 5 46 5 48 5 53 5 55 5 57 5 59 5 61 5 63 VI Introduction Cover Removal and Replacement General Measurement Technique Test Equipment Required Performance Test Rated Output and Meter Accuracy Load Regulation Line Regulation Output Impedance Current Limit Transient Recovery Time Troubleshooting Trouble Analysis Repair and Replacement Adjustment and Calibration Meter Mechanical Zero Meter Calibration Zero Volts Output Adjustment Output Current Limit Adjustment REPLACEABLE PARTS 6 1 Introduction 6 4 6 8 Ordering Information Reference Designators Abbreviations Manufacturers Code List of Manufacturers Parts List Table APPENDIX A ALD AA AL By SET SE WWNNN IE OKD OBOJE ak i VELI PA LI LA Gi Gi GH 1 U 1 A U1 01 GT M UI UI A A M GI M GA 1 oma mm HE ONN OD do WG NH sono He TABLE OF CONTENTS CONTINUED LIST OF TABLES Table Page No Table Page No 1 1 Specifications 1 2 5 4 Low Output Voltage Troubleshooting 5 10 5 1 Test Equipment Required 5 2 5 5 High Output Voltage Troubleshooting 5 11 5 2 Common Troubles 5 9 5 6 Selected Semiconductor 5 3 Reference Bias and Filtered DC Characteristics
5. Div of North American Phillips Co Inc Hicksville N Y Bradley Semiconductor Corp New Haven Conn Carling Electric Inc Hartford Conn Federal Screw Products Inc Chicago Ill Hardwick Hindle Co Memcor Components Div Huntington Ind Heinemann Electric Co Trenton N J Harvey Hubbel Inc Bridgeport Conn FXR Div of Amphenol Borg Electronics Corp Danbury Conn International Resistance Co Philadelphia Pa Howard B Jones Div of Cinch Mfg Corp Use 71785 New York N Y Kulka Electric Corp Mt Vernon N Y Littlefuse Inc Des Plaines Ill J W Miller Co Los Angeles Calif Oak Manufacturing Co Crystal Lake Ill Bendix Corp Bendix Pacific Div No Hollywood Calif Phaostron Instrument and Electronic Co South Pasadena Calif Philadelphia Steel and Wire Corp Philadelphia Pa American Machine and Foundry Potter and Brumfield Div Princeton Ind TRW Electronics Components Div Camden N J Resistance Products Co Harrisburg Pa Shakeproof Div of Illinois Tool Works Elgin Ill Stackpole Carbon Co St Marys Pa Stanwyck Winding Co Inc Newburgh N Y Tinnerman Products Inc Cleveland Ohio Whitehead Metal Products Co Inc New York N Y Continental Wirt Electronics Corp Philadelphia Pa Mepco Div of Sessions Clock Co Morristown N J Riverside Calif Bourns Inc Table 6 3 ADDRESS MANUFACTURER 81042 Racine Wis 81483 Howard Industries In
6. a two contact outlet use a three prong to two prong adapter and connect the green lead on the adapter to ground 2 22 REPACKAGING FOR SHIPMENT 2 23 To insure safe shipment of the instrument it is recommended that the package designed for the instrument be used The original packaging mate rial is reusable If it is not available contact your local Hewlett Packard field office to obtain the materials This office will also furgish the ad dress of the nearest service office to which the in strument can be shipped Be sure to attach a tag to the instrument which specifies the owner model number full serial number and service required or a brief description of the trouble SECTION III OPERATING INSTRUCTIONS 3 1 TURN ON CHECKOUT PROCEDURE 3 2 The following checkout procedure describes the use of the front panel controls and indicators and ensures that the supply is operational a Set AC toggle switch 1 upward to on position indicator 2 should light vou COARSE 6 METER SELECTION votrse Np lt ma y id s Front Panel Controls and Indicators Figure 3 1 b Set METER SELECTION switch 4 to VOLTS position c Turn COARSE 6 and FINE 5 VOLTAGE controls fully ccw to ensure that output decreases to 0V then turn the VOLTAGE controls fully cw to ensure that output voltage increases to the maxi mum rated output voltage d Connect a millia
7. ac input h Reading on differential voltmeter should not vary from reading recorded in step f by more than 4mv 5 22 Ripple and Noise Definition The residual ac voltage which is superimposed on the dc out put of a regulated power supply Ripple and noise may be specified and measured in terms of its RMS or pre ferably peak to peak value Ripple and noise measurement can be made at any input ac line voltage combined with any de output voltage and load current within rating 5 23 The amount of ripple and noise that is present on the power supply output is measured either in 5 4 terms of the RMS or preferably peak to peak value The peak to peak measurement is particu larly important for applications where noise spikes could be detrimental to a sensitive load such as logic circuitry The RMS measurement is not an ideal representation of the noise since fairly high output noise spikes of short duration could be present in the ripple and not appreciably in crease the RMS value 5 24 The technique used to measure high frequency noise or spikes on the output of a power supply is more critical than the low frequency ripple and noise measurement technique therefore the former is discussed separately in Paragraph 5 32 5 25 Ripple and Noise Measurements Figure 5 6A shows an incorrect method of measuring p p ripple Note that a continuous ground loop exists from the third wire of the input power cord of the supply to t
8. energy occurring during switching action complete ly masks the display with a noise burst Transis tor load switching devices are expensive if reason ably rapid load current changes are to be achieved 5 43 A mercury wetted relay as connected in the load switching circuit of Figure 5 9 should be used for loading and unloading the supply When this load switch is connected to a 60 Hz AG input the mercury wetted relay will open and close 60 times per second Adjustment of the 25K control permits adjustment of the duty cycle of the load current switching and reduction in jitter of the os cilloscope display 9 44 The maximum load ratings listed in Figure 5 9 must be observed in order to preserve the mercury wetted relay contacts Switching of larger load cur rents can be accomplished with mercury pool relays with this technique fast rise times can still be ob tained but the large inertia of mercury pool relays limits the maximum repetition rate of load switching and makes the clear display of the transient recovery characteristic on an oscilloscope more difficult POWER SUPPLY UNDER TEST OSCILLOSCOPE hp OA A CONTACT PROTECTION NETWORK Be LUF 400V 5N 5W NOTE 3 NOTES THIS DRAWING SHOWS A SUGGESTED METHOD OF BUILDING A LOAD SWITCH HOWEVER OTHER METHODS COULD BE USED SUCH AS A TRANSISTOR SWITCHING NETWORK MAXIMUM LOAD RATINGS OF LOAD SWITCH ARE 5 AMPS 500V 250W NOT 2500W USE MERCURY
9. instructions outlinedinthe steps below regarding etched circuit boards without eyelets are not followed extensive damage to the etched circuit board will result 1 Apply heat sparingly to lead of component 2 Reheat solder in vacant eyeletand quickly tobe replaced If lead of component passes insert a small awlto clean inside of hole through an eyelet A I hole does GONDUCTOR SIDE not have an eyelet in sert awl or a 5 drill from con ductor side of board in the circuit board apply heat on com ponent side of board If u lead of com 7 ponent does A not pass through an eyelet apply heat to conductor side of board 4 Hold partagainst board avoid overheating 3 Bend clean tinned lead on new part and and solder leads carefully insert ani Apply heat to compo through eyelets or nent leads on correct holes in board side of board as explained Vu gr ETA in step 1 In the event that either the circuit boardhas been damaged or the conventional method is imprac tical use method shown below Thisis especially applicable for circuit boards without eyelets 1 Clip lead as shown below 2 Bend protruding leads upward Bend lead of new APPLY pe SF component SOLDER d HERE around pro HEER truding lead Apply solder using a pair of long nose pliers as a heat sink VISARIS KAGUZA AZIALIAZI RARE 180080 This procedure is used in the field only as an alternate means of repair It i
10. j Adjust the sync controls separately for the positive and negative going transients so that not only the recovery waveshape but also as much as possible of the rise time of the transient is displayed E i 804 SECONDS 15 MV UNLOADING TRANSIENT LOADING TRANSIENT Figure 5 10 Transient Recovery Time Waveforms k Starting from the major graticule division representative of time zero count to the right 50 psec and vertically 10 mV Recovery should be within these tolerances as illustrated in Figure 5 10 5 8 5 46 TROUBLESHOOTING 5 47 Components within Hewlett Packard power supplies are conservatively operated to provide maximum reliability In spite of this parts within a supply may fail Usually the instrument must be immediately repaired with a minimum of down time and a systematic approach as outlined in succeeding paragraphs can greatly simplify and speed up the repair 5 48 TROUBLE ANALYSIS 5 49 General Before attempting to troubleshoot this instrument ensure that the fault is with the instrument and not with an associated circuit The performance test Paragraph 5 13 enables this to be determined without having to remove the instru ment from the cabinet 5 50 Once it is determined that the power supply is at fault check for obvious troubles such as open fuse a defective power cable or an input power failure Next remove the top and bottom covers as described in Paragra
11. negative Q1 now decreases its conduction and its collector voltage rises The positive going error voltage is amplified and inverted by Q4 and fed to the base of series transistor Q7 via emitter follower Q5 The negative going input causes Q7 to decrease its conduction so that it drops more of the line voltage and reduces the output voltage to its original level 4 10 When the external load resistance decreases the output current increases until the current limit is reached The positive voltage developed at the wiper of R50 causes Q3 to conduct CR4 becomes forward biased and controls the conduction of Q5 and Q7 Any further decreases in load resistance increase the negative voltage on the base of Q5 which decreases the conduction of Q7 Thus through feedback action the output current is limi ted to the value at which CR4 conducts 4 11 SERIES REGULATOR 4 312 The series regulator consists of transistor stage Q7 see schematic at rear of manual The regulator serves as a series control element by altering its conduction so that the output voltage is kept constant and the current limit is never ex ceeded The conduction of Q5 is controlled by the feedback voltage obtained from driver Q4 Diode CR7 connected across the regulator circuit pro tects the series transistor against reverse voltages that could develop across it during parallel or auto parallel operation if one supply is turned on before the other 4 13 CONSTANT VOLT
12. open only 00656 00853 01121 01255 01281 01295 01686 01930 02114 02606 02660 02735 03508 03797 03877 03888 04009 04072 04213 04404 04713 05277 05347 06486 06540 06555 06666 Table 6 3 Code List of Manufacturers MANUFACTURER ADDRESS EBY Sales Co New York N Y Aerovox Corp New Bedford Mass Sangamo Electric Compary Ordill Division Capacitors Marion Ill Allen Bradley Co Milwaukee Wis Litton Industries Inc Beverly Hills Calif TRW Semiconductors Inc i Lawndale Calif Texas Instruments Inc Semiconductor Components Division Dallas Texas RCL Electronics Inc Manchester N H Amerock Corp Rockford Ill Ferroxcube Corp of America Saugerties N Y Fenwal Laboratories Morton Grove Ill Amphenol Borg Electronics Corp Broadview Ill Radio Corp of America Commercial Receiving Tube and Semiconductor Div Somerville N J G E Semiconductor Products Dept Syracuse N Y Eldema Corp Compton Calif Transitron Electronic Corp Wakefield Mass Pyrofilm Resistor Co Cedar Knolls N J Arrow Hart and Hegeman Electric Co Hartford Conn ADC Electronics Inc Harbor City Calif Caddell Burns Mfg Co Inc Mineola N Y Dymec Division of Hewlett Packard Co Palo Alto Calif Motorola Inc Semiconductor Products Division Phoenix Arizona Westinghouse Electric Corp Semi Conductor Dept Youngwood Pa Ultronix Inc Gran
13. 16 RU R18 R19 R20 R21 R24 R25 R26 R27 R28 R30 R31 Table 6 4 Replaceable Parts DESCRIPTION TQ MFR PART NO MER RS CODE PART NO fxd elect Spf S0Vdo 1 30D505G050BB2 0180 0301 1 NOT ASSIGNED 5 fxd film 0047 pf 200V 1 192P47292 0160 0157 1 fxd elect 200uf 65Vdo 1 obd 0180 1884 1 fxd elect 2000pf 28Vde 1 obd 0180 1916 1 fxd cer 02pf 600Vdc 2 841 000 Z5U 203Z 0150 0024 1 NOT USED k fxd elect 100pf 65Vdc 1 obd 0180 1853 1 Rect Si 250mW 200prv 3 1N485B 1901 0033 NOT ASSIGNED 1N485B Rect Si 250mW 200prv 1901 0033 Rect Si 1A 200prv 1N5059 1901 0327 Rect Si 500mA 200prv 1N3253 1901 0389 Stabistor 400mW 10prv 1N4830 1901 0460 1901 0327 1450 0361 1N5059 6141 000 603 Red Rect Si 1A 200prv Lamp Neon AlC Red 312 005 2N3391 2N2907A 40362 2110 0012 1854 0071 1853 0099 1853 0041 Fuse cartridge 0 5A 250V 3AG SS NPN Si SS PNP Si SS PNP Si NOT ASSIGNED Power NPN Si obd 1854 0225 SS NPN Si 2N3417 1854 0087 SS PNP Si 40362 1853 0041 fxd ww lKa 45 3W 20ppm 242E1025 0813 0001 fxd met film 6 2Kn 1 1 8W CEA T O obd 0698 5087 fxd met film 20Ka 41 1 8W CEA T O obd 0757 0449 fxd comp 110Kn 5 W EB 1145 0686 1145 fxd met f
14. 4 27 This circuit provides indications of output voltage or output current With METER SELECTION switch 2 set to VOLTS position the meter in series with R38 is connected directly across the output of the supply With S2 set to the MA posi tion the meter in series with R37 and R47 is connected across the current sampling resistor R33 Potentiometer R47 adjusts the electrical meter zero in the MA position i i i SECTION V MAINTENANCE 5 1 INTRODUCTION 5 2 Upon receipt of the power supply the per formance check Paragraph 5 13 should be made This check is suitable for incoming inspection If a fault is detected in the power supply while making the performance check or during normal op eration proceed to the troubleshooting procedures Paragraph 5 46 After troubleshooting and repair Paragraph 5 53 perform any necessary adjust ments and calibrations Paragraph 5 55 Before returning the power supply to normal operation repeat the performance check to ensure that the fault has been properly corrected and that no other faults exist Before doing any maintenance checks turn on power supply allow a half hour warm up and read the general information regarding measure ment techniques Paragraph 5 6 5 3 COVER REMOVAL AND REPLACEMENT 5 4 To remove the top and bottom covers pro ceed as follows a Insert a small screwdriver in each of the four notches at the front of the unit at the top and bottom Push the s
15. AGE INPUT CIRCUIT Refer to overall schematic at rear of manual 4 14 The circuit consists of the coarse and fine programming resistors R10 and R11 and a differ ential amplifier stage Q1 Q2 and associated components Drift due to thermal differentials is minimized since both transistors operate at es sentially the same temperature 4 15 The constant voltage input circuit continu ously compares a fixed reference voltage with a portion of the output voltage and if a difference exists produces an error voltage whose amplitude and phase is proportional to the difference The error output is fed back to the series regulator through the error and driver amplifiers The error voltage changes the conduction of the series reg ulator which in turn alters the output voltage so that the difference between the two input voltages applied to the differential amplifier is reduced to zero The above action maintains the output volt age constant 4 16 Stage Q2 of the differential amplifier is con nected to a common 8 potential through imped ance equalizing resistor R6 Resistors R5 and R7 are used to zero bias the input stage offsetting minor base to emitter voltage differences in Ql and Q2 The base of Ql is connected to a sum ming point at the junction of the programming resistors and the current pullout resistor R12 Instantaneous changes in output voltage result in an increase or decrease in the summing point potential Q1 is t
16. RELAY CLARE TYPE HGP 1002 OR W E TYPE 2768 J 3 USE WIRE WOUND RESISTOR va ja LINE SWITCH n PETITI MODEL NO GRISA EZIAA 100 OW 5 650 10W t5 2500 JOW t5 215A 6216A 6217A 6218A Figure 5 9 Transient Recovery Time Test Setup 5 45 To check the transient recovery time proceed as follows a Connect test setup shown in Figure 5 9 b Set METER SELECTION switch to mA c Tum on supply and adjust voltage controls until front panel meter indicates exactly the maxi mum rated output current d Close the line switch on the repetitive load switch setup e Set the oscilloscope for internal syne and lock on either the positive or negative load tran sient spike f Set the vertical input of the oscilloscope for ac coupling so that small de level changes in the output voltage of the power supply will not cause the display to shift g Adjust the vertical centering on the scope so that the tail ends of the no load and full load waveforms are symmetrically displaced about the horizontal center line of the oscilloscope This center line now represents the nominal output volt age defined in the specification h Adjust the horizontal positioning control so that the trace starts at a point coincident with a major graticule division This point is then repre sentative of time zero i Increase the sweep rate so that a single transient spike can be examined in detail
17. a Connect test setup as shown in Figure 5 5 b Set METER SELECTION switch to MA position Turn on supply and adjust VOLTAGE controls until front panel meter indicates maximum rated output current d Read and record voltage indicated on differential voltmeter e Disconnect load resistor f Reading on differential voltmeter should not vary from reading recorded in step d by more than 4mV 5 20 LINE REGULATION Definition The change ABouT in the static value of DC output voltage result ing from a change in AC input voltage over the specified range from low line usually 105 volts to high line usually 125 volts or from high line to low line I i POWER SUPPLY UNDER TEST MODEL No RL 62I3A 6214A IG OWES 6215A 6216A 65N 10W 45 6217A 6218A 2500 10W 5 DIFFERENTIAL VOLTMETER Figure 5 5 Load Regulation Test Setup 5 21 To test the line regulation proceed as fol lows a Connect variable auto transformer be tween input power source and power supply power input b Connect test setup shown in Figure 5 5 c Adjust variable auto transformer for 105 VAC input d Set METER SELECTION switch to VOLTS position e Turn on supply and adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage f Read and record voltage indicated on dif ferential voltmeter g Adjust variable auto transformer for 125V
18. age or current OUTPUT TERMINALS i Three five way output posts are provided on the i front panel All power supply output terminals are isolated from the chassis and either the positive or negative terminal may be connected to the chassis through a separate ground terminal located on the output terminal strip COOLING Convection cooling is employed The supply has no moving parts SI E 53 13 340m W x 31 8 26cem H x 7 17 78cmD Using a Rack Mounting Kit three units can be mounted side by side ina standard 19 relay rack WEIGHT 4 5 lbs 2 0 kg net 6 5 lbs 2 9 kg shipping POWER CORD A three wire five foot power cord is provided with each unit SECTION II INSTALLATION SIDE Figure 2 1 Outline Diagram 2 1 INITIAL INSPECTION 2 2 Before shipment this instrument was inspec ted and found to be free of mechanical and electri cal defects As soon as the instrument is unpacked inspect for any damage that may have occurred in transit Save all packing materials until the in spection is completed If damage is found proceed as described in the C aim for Damage in Shipment section of the warranty page atthe rear of this manual 2 3 MECHANICAL CHECK 2 4 This check should confirm that there are no broken knobs or connectors that the cabinet and panel surfaces are free of dents and scratches and that the meter is not scra
19. amplitude to counteract the change in output voltage The ref erence regulator circuit provides stable reference voltages which are used by the constant voltage input circuit for comparison purposes The meter circuit provides indications of output voltage or current in either operating mode 4 4 Diode CR14 connected across the output terminals of the power supply is a protective de vice which prevents internal damage that might occur if a reverse voltage were applied across the output terminals 4 5 DETAILED CIRCUIT ANALYSIS Refer to overall schematic diagram at rear of manual 4 6 FEEDBACK LOOP 4 7 The feedback loop functions continuously to keep the output voltage constant during constant voltage operation and the output current at a safe limit during current limit operation For purposes of this discussion assume that the unit is in con stant voltage operation and that the programming resistors R10 and R11 have been adjusted so that the supply is yielding the desired output voltage Further assume that the output voltage instantane ously rises goes positive due to a variation in the external load circuit 4 8 Note that the change may be in the form of a slow rise in the output voltage or a positive going AC signal An AC signal is coupled to the voltage input circuit through capacitor Cl and a DC volt age is coupled through R10 and R11 4 9 The rise in output voltage causes the voltage at the base of Q1 to decrease go
20. becomes forward biased clamping the base of Q5 to a potential which decreases the conduction of the series regulator thus Limiting the output current Potentiometer R50 permits the base potential of Q3 to be varied and thus changes the current limiting threshold 4 22 REFERENCE CIRCUIT Refer to schematic at rear of manual 4 23 The reference circuit is a separate power 4 3 supply similar to the main supply It provides stable reference voltages which are used through out the unit The reference voltages are all de rived from smoothed dc obtained from the full wave rectifier CR10 and CR11 and filter capacitor C5 The 6 2V reference voltage is derived from VR1 which is a second dc source regulating at 6 2vde Current for VR1 is supplied by the side of C5 and flows through VR1 the base emitter junction of Q7 R20 and back to the positive side of C5 4 24 The base emitter junction of Q11 is held constant by 6 2V zener diode VR7 which regulates line voltage changes that alter the voltage across C5 Thus Ql1 is a constant current source feeding 12 4V zener diode VR4 and 6 2V temperature com pensated zener diode VR6 4 25 Resistors R27 and R30 form a voltage divider across the stable 6 2 volts developed by VRI The base emitter junction of Q9 is therefore held con stant by the voltage developed across R27 Thus Q9 provides a constant current to zener diode VR3 which regulates the 6 2V source 4 26 METER CIRCUIT
21. c International Rectifier Corp El Segundo Calif Columbus Electronics Corp Yonkers N Y Goodyear Sundries amp Mechanical Co Inc New York N Y Sylvania Electric Products Inc Electronic Tube Division Emporium Pa Switchcraft Inc Chicago Ill Metals and Controls Inc Spencer Products Attleboro Mass Research Products Corp Madison Wis Rotron Mfg Co Inc Woodstock N Y Vector Electronic Co Glendale Calif Carr Fastener Co Cambridge Mass Victory Engineering Corp Springfield N J Bendix Corp Red Bank Div Eatontown N J Herman H Smith Inc Brooklyn N Y Central Screw Co Chicago Ill Gavitt Wire and Cable Co Div of Amerace Corp Brookfield Mass Grant Pulley and Hardware Co West Nyack N Y Burroughs Corp Electronic Components Div Plainfield N J Yardeny Laboratories Inc New York N Y Arco Electronics Inc Great Neck N Y TRW Capacitor Div Ogallala Neb Radio Corporation of America Electronic Components amp Devices Div Harrison N J Marco Industries Co Anaheim Calif 87216 Philco Corp Lansdale Div Lansdale Pa 87585 Stockwell Rubber Co Inc Philadelphia Pa 87929 B M Tower Co Inc Bridgeport Conn 81751 82099 82219 82389 82647 82866 82877 82893 83058 83186 83298 83330 83385 83501 83508 83594 83877 84171 84411 86684 87034 Code List of Manufacturers Continued MANUFACTURER ADDRESS 88140 89473 C
22. contains the circuit diagrams neces sary for the operation and maintenance of this power supply Included are a Component Location Diagram Figure 7 1 which shows the physical location and refer ence designator of parts mounted on the printed 7 1 wiring board b Schematic Diagram Figure 7 2 which illustrates the circuitry for the entire power supply Voltages are given adjacent to test points identi fied by encircled numbers on the schematic and printed wiring board
23. cope with a bandwidth of 20 MHz or more is adequate Measuring noise with an instrument that has insufficient bandwidth may conceal high frequency spikes detrimental to the load 5 33 The test setups illustrated in Figures 5 6A and 5 6B are generally not acceptable for measur ing spikes a differential oscilloscope is neces sary Furthermore the measurement concept of Figure 5 6C must be modified if accurate spike measurement is to be achieved 1 As shown in Figure 5 7 two coax son TERMINATION T CONNECTOR N POWER SUPPLY OSCILLOSCOPE CASE CASE o 01uf 0 YA gt Tverrican INPUT AC AC ace g GNO TYERTICAL XI a ty pe INPUT Son A T CONNEC TOR 500 TERMINATION Figure 5 7 Noise Spike Test Setup cables must be substituted for the shielded two wire cable 2 Impedance matching resistors must be included to eliminate standing waves and cable ringing and the capacitors must be connected to block the DC current path 3 The length of the test leads outside the coax is critical and must be kept as short as pos sible the blocking capacitor and the impedance matching resistor should be connected directly from the inner conductor of the cable to the power supply terminals 4 Notice that the shields of the power sup ply end of the two coax cables are not connected to the power supply ground since such a connec tion would give
24. crewdriver under the front panel and gently pry toward the front of the unit to re lease the holding mechanism b Pull the front panel forward until it clears the top and bottom covers c Remove the rear cover by repeating step a d Pull the rear cover until it clears the top and bottom covers Then lift off the top cover and lift the unit out of the bottom cover 5 5 To replace the top and bottom covers pro ceed as follows a Place the unit into the bottom cover identified by the four protruding feet and align the heat sink into the track in the bottom cover b Place the top cover over the unit and align the track over the heat sink c While holding the covers together at the rear of the unit carefully push on the rear panel d Position the front panel so that the two slotted ears at the bottom of the panel align with the printed wiring boards e Carefully push on the front panel 5 6 GENERAL MEASUREMENT TECHNIQUES 5 7 The measuring device must be connected as close to the output terminals as possible when measuring the output impedance transient re sponse regulation or ripple of the power supply in order to achieve valid measurements A meas urement made across the load includes the imped ance of the leads to the load and such lead lengths can easily have an impedance several orders of magnitude greater than the supply impedance thus invalidating the measurement 5 8 The monitoring device should be con
25. d Junction Colo North American Electronics Inc Lynn Mass Amathom Electronic Hardware Co Inc New Rochelle N Y Beede Electrical Instrument Co Inc Penacook N H General Devices Co Inc Indianapolis Ind Nuclear Corp of America Inc U S Semcor Div Phoenix Arizona 07387 07397 07716 07910 07933 08530 08717 08730 08863 09182 09353 11236 11237 11711 12136 12697 14493 14655 14936 15909 16299 16758 17545 ADDRESS MANUFACTURER Torrington Mfg Co West Div Van Nuys Calif Transistor Electronics Corp Minneapolis Minn Westinghouse Electric Corp Electronic Tube Div Elmira N Y Fairchild Semiconductor Div of Fairchild Camera and Instrument Corp Mountain View Calif Birtcher Corp The Los Angeles Calif Sylvania Electric Products Inc Mountain View Operations of Sylvania Electronic Systems Mountain View Calif International Resistance Co Burlington Iowa Continental Device Corp Hawthorne Calif Raytheon Mfg Co Semiconductor Div Mountain View Calif Reliance Mica Corp Brooklyn N Y Sloan Company Sun Valley Calif Vemaline Products Co Franklin Lakes N J Nylomatic Corp Morrisville Pa Hewlett Packard Co Harrison Division Berkeley Heights N J C 6 K Components Newton Mass CTS of Berne Inc Berne Ind Chicago Telephone of California Ino So Pasadena Calif General Instrument Corp Semiconductor Prod Grou
26. dianapolis Ind Muter Co Chicago Ill Ohmite Manufacturing Co Skokie Ill Polaroid Corporation Cambridge Mass Raytheon Mfg Co Microwave and Power Tube Div Waltham Mass Simpson Electric Co Chicago IL Sprague Electric Co North Adams Mass Superior Electric Co Bristol Conn Union Carbide Corp New York N Y Ward Leonard Electric Co Mt Vernon N Y Amperite Co Inc Union City N J Belden Mfg Co Chicago Tl Bud Radio Inc Willoughby Ohio Bussmann Mfg Div of McGraw Edison Co CTS Corporation I T T Cannon Electric Inc Los Angeles Calif Centralab Div of Globe Union Inc Milwaukee Wis The Cornish Wire Co New York N Y Chicago Miniature Lamp Works Chicago Ill Chicago Ill Midland Mich Brooklyn N Y St Louis Mo Elkhart Ind Cinch Mfg Co Dow Corning Corp Dialight Corporation General Instrument Corp Capacitor Div Newark N J Drake Mfg Co Chicago Ill Erie Technological Products Inc Erie Pa 6 3 Code List of Manufacturers Continued MANUPACTURER ADDRESS 73138 73293 73445 73506 73559 73734 73978 74193 74545 74868 75042 75183 75382 75915 76493 76854 77068 77221 77252 77342 77630 77764 78189 78488 78526 78553 79307 79727 80294 80031 Helipot Div of Beckman Instruments Inc Fullerton Calif Hughes Components Division of Hughes Aircraft Co Newport Beach Calif Amperex Electronic Co
27. e to the output capacitor To avoid these effects it is necessary to preload the sup ply with a dummy load resistor so that the power supply delivers current through the entire operating cycle of the load device 3 26 Reverse Voltage Protection A diode is con nected across the output terminals with reverse polarity This diode protects the output electro lytic capacitors and the series regulator transistors from the effects of a reverse voltage applied across the output terminals For example in series oper ation of two supplies if the AC is removed from one supply the diode prevents damage to the un energized supply which would otherwise result from a reverse polarity voltage Since series regulator transistors or driver transistors cannot withstand reverse voltage another diode is connected across the series tran sistor This diode protects the series transistors in parallel or Auto Parallel operation if one supply of the parallel combination is turned on before the other i SECTION IV PRINCIPLES OF OPERATION SERIES REGULATOR Q7 ON OFF SWITCH NOTE 1 MAIN SUPPLY OUTPUT VOLTAGES AR MODEL voc 62138 22 6215A 44 62I7A 83 Figure 4 1 4 1 SIMPLIFIED DISCUSSION 4 2 The power supply as shown on the simplified schematic diagram of Figure 4 1 consists of a power transformer rectifier and filter series regu lator error amplifier and driver c
28. he third wire of the input power cord of the oscilloscope via the grounded power supply case the wire between the negative output termi nal of the power supply and the vertical input of the scope and the grounded scope case Any ground current circulating in this loop as a result of the difference in potential Eq between the two ground points causes an IR drop which is in series with the scope input This IR drop normally having a 60 Hz line frequency fundamental plus any pickup on the unshielded leads interconnect ing the power supply and scope appears on the face of the CRT The magnitude of this resulting noise signal can easily be much greater than the true ripple developed between the plus and minus output terminals of the power supply and can completely invalidate the measurement 5 26 The same ground current and pickup problems can exist if an RMS voltmeter is substituted in place of the oscilloscope in Figure 5 6 However the oscilloscope display unlike the true RMS meter reading tells the observer immediately whether the fundamental period of the signal dis played is 8 3 milliseconds 1 120 Hz or 16 7 milliseconds 1 60 Hz Since the fundamental ripple frequency present on the output of an amp supply is 120 Hz due to full wave rectification an oscilloscope display showing a 120 Hz funda mental component is indicative of a clean measurement setup while the presence of a 60 Hz fundamental usually means that an impr
29. hen made to conduct more or less in accordance with the summing point volt age change The resultant output error voltage is fed back to the series regulator via the remaining components of the feedback loop Resistor R1 in series with the base Q1 limits the current through the programming resistors during rapid voltage tum down Diodes CR and CR2 form a limiting network which prevents excessive voltage excur sions from over driving stage Q1 Capacitor Cl shunting the programming resistors increases the high frequency gain of the input amplifier 4 17 DRIVER AND ERROR AMPLIFIER Refer to over all schematic at rear of manual 4 18 The error and driver amplifiers amplify the error signal from the constant voltage input circuit to a level sufficient to drive the series regulator transistor Driver Q5 also receives a current limiting input if CR4 the current limiting diode becomes forward biased 4 19 Stage Q4 contains a feedback equalizer net work C3 and R17 which provides for high fre quency roll off in the loop gain in order to stabi lize the feedback loop 4 20 CURRENT LIMITING CIRCUIT 4 21 Current limiting occurs when transistor Q3 conducts This is determined by the voltage drop across current sampling resistor R33 and the adjust ment of current limit potentiometer R50 When the output current reaches the limit value the positive voltage with respect to 8 on the wiper arm of R50 causes Q3 to conduct Diode CR4
30. icular frequency is of engineering importance 5 36 To check the output impedance proceed as follows a Connect test setup shown in Figure 5 8 VOLTMETER hp 4038 INDICATES Eo VOLTMETER hp4038 INDICATES Ein o o POWER SUPPLY UNDER TEST OSCILLATOR hp 200 CD Figure 5 8 Output Impedance Test Setup b Set METER SELECTION switch to VOLTS position c Turn on supply and adjust VOLTAGE con trols until front panel meter reads 20 volts d Set AMPLITUDE control on Oscillator to 10 volts Ein and FREQUENCY control to 100 Hz e Record voltage across output terminals of the power supply Eo as indicated on AC voltmeter f Calculate the output impedance by the following formula Zout oe in 7 Eo Eg rms voltage across power supply output terminals R 1000 Ein 10 volts g The output impedance Zout should be less than 0 030 ohms 5 6 h Using formula of step f calculate output impedance at frequencies of 50kHz and 500 kHz Values should be less than 0 5 ohm and 3 0 ohms respectively 5 37 Output Induciance To check the output in ductance repeat steps a through f at frequencies of 10kHz 50kHz and 100kHz Calculate the out put inductance L using the following formula XL La See Note 2nf The oscillator frequency is equivalent to f in the equation The output inductance should be less than 20 microhenries NOTE The equation assumes that Xz is much greater than Ro
31. ilm 1 5Kn 1 1 8W CEA T O obd 0757 0427 fxd comp 560Kn 5 4 W EB 5645 0686 5645 NOT ASSIGNED 2100 1858 var ww 50n 5 2W 1 obd var ww 5Ka 5 2W 1 obd 2100 1853 fxd ww 2 6Kn 5 3W 20ppm 1 24262625 0811 1808 fxd comp 2 2Kn 5 W 1 EB 2225 0686 2225 fxd comp 4 7Ka 5 3 W 1 EB 4725 0686 4725 fxd comp 6 2Kn 5 W 1 EB 6225 0686 6225 fxd comp 1Ka 5 3 W 1 EB 1025 0686 1025 fxd ww 1 2Kn 5 3W 1 24261225 0811 1208 fxd comp 300a 45 4W 1 EB 3015 0686 3015 fxd comp 3 6Ka 45 1W 1 GB 3625 0689 3625 fxd comp 620n 45 3 W 2 EB 6215 0686 6215 fxd comp 160n 45 W 1 EB 1615 0686 1615 fxd comp 200a 45 3 W 1 EB 2015 0686 2015 fxd comp 2 2Kn 5 1W 1 GB 2225 0689 2225 fxd comp 470n 5 7 W 1 EB 4715 0686 4715 fxd comp 620a 5 W B 6215 0686 6215 6213A 6 5 REF R MFR GR DE I MFR P NO DESIG DESCRIPTION MFR PART NO CODE PART NO fxd ww 390n 5 3W 24263915 0811 1799 fxd ww la 5 5W 20ppm obd 0811 1340 fxd met film 1Ka 1 1 8W CEA T O obd 0757 0280 fxd comp 56 5 3 W EB 5605 0686 5605 fxd comp 12Kn 5 W EB 1235 0686 1235 fxd met film 12Kn 1 1 8W CEA T O obd 0698 5088 fxd comp 68Kn 5 W EB 6835 0686 6835 var ww 250n 20 110 F4 obd 2100 0439 var ww 100n 20 110 F4 obd 2100 0281 Switch toggle power 7101 3101 0163 Switch slide DPDT knob term XA 70420
32. ing indications on the multimeter Model Current Limit 6213A 1300mA 6215A 475mA 6217A 250mA SECTION VI REPLACEABLE PARTS 6 1 INTRODUCTION Table 6 1 Reference Designators Continued 6 2 This section contains information for ordering E misc electronic RT thermistor replacement parts part S switch i F fuse T transformer 6 3 Table 6 4 lists parts in alpha numerical order J jack V vacuum tube i of the reference designators and provides the fol K relay neon bulb lowing information L inductor photocell etc a Reference Designators For abbreviations M meter X m socket refer to Table 6 1 P plug XF fuseholder b Description Refer to Table 6 2 for abbre Q transistor XDS lampholder viations R resistor Z network Total Quantity TQ used in the instru ment given only first time the part number is listed Table 6 2 Description Abbreviations d Manufacturer s part number e Manufacturers code number Refer to a amperes obd order by descrip Table 6 3 for manufacturer s name and address c carbon tion f 6 Part Number cer ceramic p peak g Recommended spare parts quantity RS coef coefficient pc printed circuit for complete maintenance of one instrument during com common board one year of isolated service comp composition pf picofarads h Parts not identified by a reference desig conn connection 10712 farads nator are
33. ique refer to Paragraph 5 6 Check reference circuit voltages Table 5 3 Poor load regulation Constant Voltage Improper measuring technique refer to Paragraph 5 6 b Check reference circuit voltages Table 5 3 Ensure that supply is not in current limit operation under loaded conditions To prevent this condition ensure that output cur rent does not exceed maximum rated output Oscillates Check C3 and R17 Poor stability Constant Voltage a Check 6 2Vdc reference voltage Table 5 3 b Noisy programming resistor R10 or R11 c CRI CR2 leaky d Check R1 R12 and Cl for noise or drift Stage Q1 Q2 defective Table 5 3 Reference Bias and Filtered DC Troubleshooting METER METER NORMAL NORMAL PROBABLE COMMON POSITIVE VDC RIPPLE P P CAUSE 6 2 0 3V VR3 Q9 R30 VR8 12 4 amp 0 6V VR1 R27 R30 22 4 2 2V 6213A CR15 CR16 C9 R32 T1 44 4 5V 6215A 78 7 8V 6217A Table 5 4 Low Output Voltage Troubleshooting PROBABLE CAUSE Turn the VOLTAGE control fully clockwise and disconnect the load To eliminate the current limit Output increases CR4 or Q3 defective circuit as a cause of the mal function remove CR4 cathode or anode lead Output remains Reconnect CR4 and proceed low to Step 3 Check conduction of Q7 by con Output remains Q7 CR7 or associated parts necting a fumper between Q5 low defecti
34. listed at the end of Table 6 4 under Mis crt cathode ray pp peak to peak cellaneous tube ppm parts per million dep deposited pos position s 6 4 ORDERING INFORMATION elect electrolytic poly polystyrene encap encapsulated pot potentiometer 6 5 To order a replacement part address order or f farads pry peak reverse inquiry to your local Hewlett Packard sales office fxd fixed voltage see lists at rear of this manual for addresses GE germanium rect rectifier grd ground ed rot rotary 6 6 Specify the following information for each h henries rms root mean square part Hg mercury s b slow blow a Model and complete serial number of impg impregnated sect section s instrument ins insulation ed Si silicon b Hewlett Packard part number K kilo 1000 sil silver c Circuit reference designator lin linear taper s slide d Description log logarithmic td time delay i taper TiO titanium dioxide 6 7 To order a part not listed in Table 6 4 give mA milli 1073 tog toggle a complete description of the part and include its M megohms tol tolerance function and location ma milliamperes trim trimmer u micro 1076 twt traveling wave mfr manufacturer tube Table 6 1 Reference Designators mig mounting variable my mylar with assembly CR diode NC normally watts B motor DS device closed without C capacitor signaling lamp Ne neon cabinet mount NO normally
35. ls the scope case and the third wire of the power supply cord 5 28 Either a twisted pair or preferably a shield ed two wire cable should be used to connect the output terminals of the power supply to the verti cal input terminals of the scope When using a twisted pair care must be taken that one of the two wires is connected both to the grounded ter minal of the power supply and the grounded input terminal of the oscilloscope When using shield ed two wire it is essential for the shield to be connected to ground at one end only so that no ground current will flow through this shield thus inducing a noise signal in the shielded leads 5 29 To verify that the oscilloscope is not dis playing ripple that is induced in the leads or pick 5 5 ed up from the grounds the scope lead should be shorted to the scope lead at the power sup ply terminals The ripple value obtained when the leads are shorted should be subtracted from the actual ripple measurement 5 30 In most cases the single ended scope method of Figure 5 6B will be adequate to eliminate non real components of ripple and noise so that a satisfactory measurement may be obtained How ever in more stubborn cases or in measurement situations where it is essential that both the power supply case and the oscilloscope case be connect ed to ground e g if both are rack mounted it may be necessary to use a differential scope with floating input as shown in Figu
36. mmeter across the out put of the supply 3 to check that the current limit circuit within the supply is limiting the out put current to Model Current Limit 6213A 1300 450mA 6215A 475 10mA 6217A 250 10mA e Remove milliammeter and connect load to output terminals 3 3 OPERATION 3 4 The power supply can be operated as a single unit normal operation in parallel or in series The output of the supply can be floated up to 300 volts off ground 3 5 CONSTANT VOLTAGE 3 6 To select a constant voltage output turn on the supply and with no load connected adjust the VOLTAGE controls for the desired output volt age To check the current limit connect an ex ternal ammeter across the output of the supply tum the VOLTAGE controls fully clockwise and observe the reading The current limit is factory adjusted in excess of the current rating of the supply If the existing current is not compatible with the anticipated load requirements the limit can be changed as outlined in the following para graphs 3 7 CHANGING CURRENT LIMIT 3 8 The current limit can be varied by adjusting resistor R50 located on the printed wiring board This adjustment procedure is described in Para graph 5 63 The range of the current limit control R50 is as follows Model Current Limit Range 6213A 800 1700mA 6215A 300 540mA 6217A 180 300mA The current limit is normally adjusted to a value far in excess of the current rating
37. nected as shown in Figure 5 1 Note that when measure ments are made at the front terminals the monitor ing leads are connected at A not B as shown in Figure 5 1 Failure to connect the measuring de vice at A will result in a measurement that includes the resistance of the leads between the output terminals and the point of connection OUTPUT TERMINAL l GN LOAD Time med MONITOR HERE Figure 5 1 Front Panel Terminal Connections 5 9 For output current measurements the current sampling resistor should be a four terminal resis tor The four terminals are connected as shown in Figure 5 2 In addition the resistor should be of the low noise low temperature coefficient less than 30 ppm C type and should be used at no more than 5 of its rated power so that its temper ature rise will be minimized CURRENT SAMPLING TERMINALS EXTERNAL LOAD TO UNGROUNDED TERMINALOF POWER SUPPLY TO GROUNDED TERMINAL OF pi SAMPLING POWER SUPPLY RESISTOR LOAD TERMINALS Figure 5 2 Output Current Measurement Technique 5 10 When using an oscilloscope ground one ter minal of the power supply and then ground the case of the oscilloscope to this same point Make certain 5 11 TEST EQUIPMENT REQUIRED that the case is not also grounded by some other means power line Connect both oscilloscope in 5 12 Table 5 1 lists the test equipment required to put lead
38. of the supply to prevent the deterioration of line and load regulation Therefore if for any reason the current limit is adjusted so that the output current js c ose to this value the performance will not meet the published specifications 3 9 CONNECTING LOAD 3 10 Each load should be connected to the power supply output terminals using separate pairs of connecting wires This will minimize mutual coup ling effects between loads and will retain full ad vantage of the low output impedance of the power supply Each pair of connecting wires should be as short as possible and twisted or shielded to re duce noise pickup If shield is used connect one end to power supply ground terminal and leave the other end unconnected 3 11 If load considerations require that the output power distribution terminals be remotely located from the power supply then the power supply out put terminals should be connected to the remote distribution terminals via a pair of twisted or shielded wires and each load separately connected to the remote distribution terminals 3 12 OPERATION OF SUPPLY BEYOND RATED OUTPUT 3 13 The shaded area on the front panel meter face indicates the amount of output voltage or current that is available in excess of the normal rated output Although the supply can be operated in this shaded region without being damaged it cannot be guaranteed to meet all of its performance specifications However if the line voltage i
39. onstant voltage input circuit current limiting circuit reference regulator circuit and a metering circuit 4 3 The input line voltage passes through the power transformer to the rectifier and filter The rectifier filter converts the ac input to raw de which is fed to the positive terminal via the regu lator and current sampling resistor network The DRIVER Q5 REFERENCE REGULATOR Q9 OI METER CIRCUIT S R33 CURRENT SAMPLING 8 2V RESISTOR Ri2 co CURRENT NSTANT VOLTAGE LIMIT AMPL PULLOUT VOLTAGE ERROR AMPL af RH COARSE VOLTAGE RIO FINE VOLTAGE Simplified Schematic regulator part of the feedback loop is made to alter its conduction to maintain a constant output voltage The voltage developed across the current sampling resistor is the input to the current limit ing circuit If the output current that passes through the sampling resistor exceeds a certain predetermined level the current limiting circuit applies a feedback signal to the series regulator which alters the regulator s conduction so that the output current does not exceed the current limit The constant voltage input circuit obtains its input by sampling the output voltage of the supply Any changes in output voltage are detected in the con stant voltage input circuit amplified by the error amplifier and driver and applied to the series regulator inthe correct phase and
40. oved setup will result in a more accurate and lower value of measured ripple 5 27 Figure 5 6B shows a correct method of meas uring the output ripple of a constant voltage power supply using a single ended scope The ground loop path is broken with a 3 to 2 adapter in series with the power supply s AC line plug Notice i i i I i POWER SUPPLY CASE OSCILLOSCOPE CASE OVERTICAL A INCORRECT METHOD GROUND CURRENT Ig PRODUCES 60 CYCLE DROP IN NEGATIVE LEAD WHICH ADDS TO THE POWER SUPPLY RIPPLE DISPLAYED ON SCOPE POWER SUPPLY CASE OSCILLOSCOPE CASE ac ACC GND TWISTED PAIR VERTICAL USE 3 TO 2 INPUT ADAPTER TO BREAK GND PATH di B A CORRECT METHOD USING A SINGLE ENDED SCOPE 3 T0 2 ADAPTER BREAKS GROUND CURRENT LOOP TWISTED PAIR REDUCES STRAY PICKUP ON SCOPE LEADS POWER SUPPLY CASE OSCILLOSCOPE CASE VERTICAL INPUT SHIELDED TWO WIRE O i C A CORRECT METHOD USING A DIFFERENTIAL SCOPE WITH FLOATING INPUT GROUND CURRENT PATH IS BROKEN COMMON MODE REJECTION OF DIFFERENTIAL INPUT SCOPE IGNORES DIFFERENCE IN GROUND POTENTIAL OF POWER SUPPLY 8 SCOPE SHIELDED TWO WIRE FURTHER REDUCES STRAY PICK UP ON SCOPE LEAD Figure 5 6 Ripple and Noise Test Setup however that the power supply case is still con nected to ground via the power supply output ter minals the leads connecting these terminals to the scope termina
41. p Rectifier Div Newark N J Philadelphia Handle Co Inc Camden N Clarostat Mig To Dover N H Hewlett Packard Co Loveland Division Loveland Colo Cornell Dubilier Elec Corp Newark N J General Instrument Corp Semiconductor Prod Group Semiconductor Div Hicksville N Y Daven Div of Thos Edison Industries McGraw Edison Co Livingston N J Corning Glass Works Electronic Components Div Raleigh N C Delco Radio Div of General Motors Corp Kokomo Ind Atlantic Semiconductors Inc Asbury Park N J Table 6 3 19315 19701 21520 22229 22767 24446 24455 24655 28480 28520 33173 35434 37942 42190 44655 47904 49956 55026 56289 58474 61637 63743 70563 70903 71218 71400 71450 71468 71590 71700 71744 71785 MANUFACTURER ADDRESS The Bendix Corp Eclipse Pioneer Div Teterboro N Electra Mfg Co Independence Kan Fansteel Metallurgical Corp No Chicago Ill Union Carbide Corp Linde Div Kemet Dept Mountain View Calif ITT Semiconductors A Division of International Telephone amp Telegraph Corp Palo Alto Calif General Electric Co Schenectady N Y General Electric Co Lamp Division Nela Park Cleveland Ohio General Radio Co West Concord Mass Hewlett Packard Co Palo Alto Calif Heyman Mfg Co Kenilworth N J G E Tube Dept Owensboro Ky Lectrohm Inc Chicago IL P R Mallory amp Co Inc In
42. ph 5 3 and inspect for open connections charred components etc If the trouble source cannot be detected by visual inspection follow the detailed procedure outlined in succeed ing paragraphs Once the defective component has been located by means of visual inspection or trouble analysis correct it and re conduct the per formance test If a component is replaced refer to the repair and replacement and adjusiment and cal ibration paragraphs in this section 5 51 A good understanding of the principles of op eration is a helpful aid in troubleshooting and it is recommended that the reader review Section IV of the manual before attempting to troubleshoot the unit in detail Once the principles of operation are understood logical application of this knowledge used in conjunction with the normal voltage readings shown on the schematic and the additional proce dures given in the following paragraphs should suf fice to isolate a fault to a component or small group of components The normal voltages shown on the schematic are positioned adjacent to the applicable test points identified by encircled numbers on the schematic and printed wiring boards 5 52 Table 5 2 includes the symptoms and probable causes of many possible troubles If either high or low output voltage is a symptom there are two me thods of isolating the fault The first is a simpli fied procedure that involves only measuring volt ages the second is a more thorough ap
43. pro ceed as follows a Connect load resistor RI indicated in Figure 5 4 across the output terminals of supply b Connect differential voltmeter across and terminals of supply observing correct po larity c Set METER SELECTION switch to VOLTS and turn on supply d Adjust VOLTAGE controls until front panel meter indicates exactly the maximum rated output voltage e Differential voltmeter should indicate maximum rated output voltage within 2 5 17 Current To check the output current pro ceed as follows a Connect test setup shown in Figure 5 4 5 3 MODEL NO 62 3A 6214A 185 6215A 6216A w 35 62I7A 6218A 2500 IOW 15 POWER SUPPLY UNDER TEST LOAD DIFFERENTIAL RESISTOR VOLTMETER CURRENT SAMPLING RESISTOR REFER TO R33 IN PARTS LIST SECTION VI Figure 5 4 Output Current Test Setup b Set METER SELECTION switch to MA position c Turn on supply and adjust VOLTAGE con trols until front panel meter indicates maximum rated output current d Differential voltmeter should read as follows Model No Reading Vdc 6213A 1 0 03V 6215A 1 2 0 036V 6217A 1 2 0 036V 5 18 LOAD REGULATION Definition The change AEoUT in the static value of DC output voltage re sulting from a change in load resist ance from open circuit to a value which yields maximum rated output current or vice versa 5 19 To check the constant voltage load regula tion proceed as follows
44. proach re quiring that transistor stages be opened or shorted Both methods are described as follows l First the reference bias and filtered feedback loop is not always conclusive a better dc voltages as given in Table 5 3 should be check method is described in 2 ed Then the voltage levels at critical points 2 First measure the reference bias and base and collector in the feedback loop should filtered dc voltages as given in Table 5 3 Then be measured and compared to the normal voltages drive each stage in the feedback loop into conduc given on the overall schematic diagram at the rear tion or cutoff by either shorting or opening the pre of the manual This method of troubleshooting a vious stage as indicated in Tables 5 4 or 5 5 Table 5 2 Common Troubles PROBABLE CAUSE Refer to Table 5 3 then 5 4 Refer to Table 5 3 then 5 5 SYMPTOM Low output or no output voltage High output voltage High ripple Check operating setup for ground refer to Paragraph 5 22 b If output floating connect luf capacitor between output and ground Check for excessive internal ripple refer to Table 5 3 d Ensure that supply is not in current limit operation under loaded conditions To prevent this condition increase load resistance so that output current does not exceed maximum rated output Check for low voltage across C5 or C9 Poor line regulation Improper measuring techn
45. rce will deliver only that fraction of its total rated output current which is necessary to fulfill the total current demand 3 19 SPECIAL OPERATING CONSIDERATIONS 3 20 PULSE LOADING 3 21 The power supply will automatically cross over from constant voltage to current limit operation in response to an increase over the preset limit in the output current Although the preset limit may be set higher than the average output current high peak currents as occur in pulse loading may exceed the preset current limit and cause crossover to occur If this cross over limiting is not desired set the preset limit for the peak requirement and not the average 3 22 OUTPUT CAPACITANCE 3 23 An internal capacitor across the output terminals of the power supply helps to supply high current pulses of short duration during con stant voltage Operation Any capacitance added externally will improve the pulse current capabil ity but will decrease the safety provided by the current limiting circuit A high current pulse may damage load components before the average output current is large enough to cause the current limit ing circuit to operate 3 24 REVERSE CURRENT LOADING 3 25 Active loads connected to the power supply may actually deliver a reverse current to the power supply during a portion of its operating cycle An external source cannot be allowed to pump current into the supply without loss of regulation and pos sible damag
46. re 5 60 If desired two single conductor shielded cables may be sub stituted in place of the shielded two wire cable with equal success Because of its common mode rejection a differential oscilloscope displays only the difference in signal between its two vertical input terminals thus ignoring the effects of any common mode signal introduced because of the difference in the AC potential between the power supply case and scope case Before using a differential input scope in this manner however it is imperative that the common mode rejection capability of the scope be verified by shorting together its two input leads at the power supply and observing the trace on the CRT If this trace is a straight line the scope is properly ignoring any common mode signal present If this trace is not a straight line then the scope is not reject ing the graund signal and must be realigned in ac cordance with the manufacturer s instructions until proper common mode rejection is attained 5 31 To check the ripple and noise output pro ceed as follows a Connect the oscilloscope or RMS volt meter as shown in Figures 5 6B or 5 6C b Adjust VOLTAGE control until front panel meter indicates maximum rated output voltage c The observed ripple and noise should be less than 200pVrms and 1mV p p 5 32 Noise Spike Measurement When a high fre quency spike measurement is being made an in strument of sufficient bandwidth must be used an oscillos
47. rent within rating RIPPLE AND NOISE Less than 200pVrms 1mV p p dg to 20MHZ TEMPERATURE RANGES Operating 0 to 55 C Storage 40 to 75 C TEMPERATURE COEFFICIENT Less than 0 02 plus lmV per degree centigrade change in ambient following 30 minutes warm up STABILITY Less than 0 1 plus 5mV total drift for 8 hours after an initial warm up time of 30 minutes at con stant ambient constant line voltage and constant load INTERNAL IMPEDANCE AS A CONSTANT VOLTAGE SOURCE Less than 0 03 ohms from de to 1kHz Less than 0 5 ohms from kHz to 100kHz Less than 3 0 ohms from 100kHz to IMHz TRANSIENT RECOVERY TIME Less than S0usec for output voltage recovery in constant voltage operation to within 15mV of the nominal output voltage following a change in out put current equal to the current rating of the suppiy The nominal output voltage is defined as the mean Specifications between the no load and full load voltages RESOLUTION lt 5mV i OVERLOAD PROTECTION A fixed current limiting circuit protects the power supply for all overloads including a direct short placed across the output terminals in constant volt age operation METER The front panel meter can be used as either a 0 12V voltmeter or as a 0 1 2A ammeter d OUTPUT CONTROLS On off switch and separate pilot light one turn coarse and fine voltage controls set desired output voltage Meter switch selects volt
48. rise to a ground current path through the coax shield resulting in an erroneous measurement 5 The measured noise spike values must be doubled since the impedance matching resis tors constitute a 2 to l attenuator 6 The noise spikes observed on the oscil loscope should be less than 0 5mV p p 5 34 The circuit of Figure 5 7 can also be used for the normal measurement of low frequency ripple and noise simply remove the four terminating re sistors and the blocking capacitors and substitute a higher gain vertical plug in in place of the wide band plug in required for spike measurements Notice that with these changes Figure 5 7 be comes a two cable version of Figure 5 60 5 35 OUTPUT IMPEDANCE Definition At any given frequency of load change AEOUT Alout Strictly speaking the definition applies only for a sinusoidal load disturbance unless of course the measurement is made at zero frequency DC The output im pedance of an ideal constant voltage power supply would be zero at all fre quencies while the output impedance for an ideal constant current power supply would be infinite at all fre quencies The output impedance of a power supply is normal ly not measured since the measurement of tran sient recovery time reveals both the static and dynamic output characteristics with just one meas urement The output impedance of a power supply is commonly measured only in those cases where the exact value at a part
49. rmits series and parallel connec tion of two or more supplies when greater voltage or current is desired 1 3 Either the positive or negative output terminal may be grounded or the power supply can be opera ted floating at up to a maximum of 300 volts off ground 1 4 A single meter is used to measure either out put voltage or output current in volts and milliamps respectively The voltage or current range is selec ted by the METER switch on the front panel 15 SPECIFICATIONS 1 6 Detailed specifications for the power supply are given in Table 1 1 1 7 OPTIONS 1 8 Options are factory modifications of a stand ard instrument that are requested by the customer The following options are available for the instru ment covered by this manual Where necessary de tailed coverage of the options is included through out the manual Option No Description 28 230Vac 50 400Hz Single Phase Output Factory modification consists of reconnecting the input transformer for 230Vac operation Refer to Section II for further details 1 9 ACCESSORIES 1 10 The accessories listed in the following chart may be ordered with the power supply or separately from your local Hewlett Packard field sales office refer to list at rear of manual for addresses Gg Part No Description 14521A 34 High Rack Kit for mounting up to three BENCH supplies Refer to Sec tion II for details 14522A 7 High Rack Kit for mounting up to six BENCH s
50. ry substitute for a differen the null detector that is used Examples tial voltmeter is to arrange a reference of satisfactory null detectors are 4419A voltage source and null detector as null detector a dc coupled oscilloscope shown in Figure 5 3 The reference utilizing differential input or a 50mv voltage source is adjusted so that the meter movement with a 100 division voltage difference between the supply scale For the latter a 2mv change in being measured and the reference volt voltage will result in a meter deflection age will have the required resolution of four divisions 5 2 POWER SUPPLY UNDER TEST REFERENCE VOLTAGE SOURCE NULL DETECTOR Q Figure 5 3 Differential Voltmeter Substitute Test Setup CAUTION Care must be exercised when using an electronic null detector in which one input terminal is grounded to avoid ground loops and circulating currents 5 13 PERFORMANCE TEST 5 14 The following test can be used as an incom ing inspection check and appropriate portions of the test can be repeated either to check the oper ation of the instrument after repairs or for periodic maintenance tests The tests are performed using a 115 VAC 60 Hz single phase input power source If the correct result is not obtained for a particular check do not adjust any controls proceed to troubleshooting Paragraph 5 48 5 15 RATED OUTPUT AND METER ACCURACY 5 16 Voltage To check the output voltage
51. s maintained above 115 VAC the supply will probably operate within its specifications 3 14 OPTIONAL OPERATING MODES 3 15 SERIES OPERATION 3 16 Normal Series Connections Two or more power supplies can be operated in series to obtain a higher voltage than that available from a single supply When this connection is used the output voltage is the sum of the voltages of the individual supplies Each of the individual supplies must be adjusted in order to obtain the total output voltage The power supply contains a protective diode con nected internally across the output which protects the supply if one power supply is turned off while its series partner s is on 3 17 PARALLEL OPERATION 3 18 Normal Parallel Connections Two or more power supplies can be connected in parallel to ob tain a total cutput current greater than that avail able from one power supply The total output cur rent is the sum of the output currents of the indi vidual power supplies The output CURRENT con trols of each power supply can be separately set The output voltage controls of one power supply should be set to the desired output voltage the other power supply should be set for a slightly larger output voltage The supply set to the lower output voltage will act as a constant voltage source the supply set to the higher output will act asacurrent limit source dropping its output voltage until it equals that of the other supply The constant voltage sou
52. s not used within the factory Figure 5 11 Servicing Printed Wiring Boards Table 5 7 Calibration Adjustment Summary Adjustment or Calibration Paragraph Control Device Meter Zero Ammeter Tracking Zero Volt Output Current Limit 5 55 ADJUSTMENT AND CALIBRATION 5 56 Adjustment and calibration may be required after performance testing troubleshooting or re pair and replacement Perform only those adjust ments that affect the operdtion of the faulty circuit and no others Table 5 7 summarizes the adjust ments and calibrations contained in the following paragraphs 5 57 METER MECHANICAL ZERO 5 58 Proceed as follows to zero meter a Turn off instrument after it has reached normal operating temperature and allow 30 sec onds for all capacitors to discharge b Insert sharp pointed object pen point or awl into the small hole at top of round black plastic disc located directly below meter face c Rotate plastic disc clockwise cw until meter reads zero then rotate ccw slightly in order to free adjustment screw from meter suspension If pointer moves repeat steps b and c 5 59 METER CALIBRATION 5 60 To calibrate the ammeter proceed as follows a Connect test setup as shown on Figure 5 4 b Set METER SELECTION switch to mA position c Tum on supply and adjust VOLTAGE con trols so that differential voltmeter indicates exactly 1 2 volts for 6215A and 6217A and 1 Volt for 6213A d Adj
53. s to the power supply ground terminal and perform the various procedures described in this check that the oscilloscope is not exhibiting a rip Section ple or transient due to ground loops pick up or other means Table 5 1 Test Equipment Required REQUIRED RECOMMENDED Differential Sensitivity 1mV full scale min Measure DC voltages 6 3420 See Note Voltmeter Input impedance 10 megohms min calibration procedures Variable Range 90 130 volts Equipped witht Vary AC input Voltage voltmeter accurate within 1 volt AC Voltmeter Accuracy 2 Sensitivity 1mV Measure AC voltages and 6 403B full scale deflection min ripple Sensitivity 100pV cm Differ ential input 140A plus 1400A plug in 1402A plug in for spike measurements only Oscilloscope Display transient response waveforms Oscillator Range 5Hz to 600KHz Accuracy 2 Output 10Vrms Impedance checks DC Voltmeter Accuracy 1 Input resistance Measure DC voltages 20 000 ohms volt min Repetitive Rate 60 400Hz 2psec rise and Measure transient response See Figure 5 9 Load Switch fall time Values See Paragraph 5 16 Power supply load resistors Loads Current Sam See R33 in Parts List Section VI Measure current calibrate pling Resistor meter SESTO NOTE for the measurement being made The voltage difference will be a function of A satisfacto
54. tched or cracked 2 5 ELECTRICAL CHECK 2 6 The instrument should be checked against its electrical specifications Section V includes an in cabinet performance check to verify proper ine strument operation 2 1 INSTALLATION DATA 2 8 The instrument is shipped ready for bench operation It is necessary only to connect the in strument to a source of power and it is ready for operation 2 9 LOCATION 2 10 This instrument is air cooled Sufficient space should be allotted so that a free flow of cooling air can reach the rear of the instrument when it is in operation It should be used in an area where the ambient temperature does not ex ceed 55 C 2 11 OUTLINE DIAGRAM 2 12 Figure 2 1 illustrates the outline shape and dimensions of Models 6213A through 6218A 2 13 RACK MOUNTING 2 14 This instrument may be rack mounted sepa rately or with a maximum of two other BENCH Series supplies as shown in Figure 2 2 The Figure 2 2 Rack Kit with Three BENCH Supplies units are placed in the Rack Mounting Frame The Rack Mounting Frame is then fastened to the rack frame 2 15 INPUT POWER REQUIREMENTS 2 16 This power supply may be operated continu ously from either a nominal 115 Volt or 230 Volt 50 400Hz power source The unit as shipped from the factory is wired for 115 Volt operation The input power required when operated from a 115 Volt power source at full load is Model Input Current Input Po
55. upplies Refer to Sec tion II for details 1 11 INSTRUMENT MANUAL IDENTIFICATION 1 12 Hewlett Packard power supplies are identified by a three part serial number tag The first part is the power supply model number The second part is the serial number prefix which consists of a num ber letter combination that denotes the date of a significant design change The number designates the year and the letter A through L designates the month January through December respectively The third part is the power supply serial number 1 13 If the serial number prefix on your power sup ply does not agree with the prefix on the title page of this manual change sheets are included to up date the manual Where applicable backdating information is given in an appendix at the rear of the manual 1 14 ORDERING ADDITIONAL MANUALS 1 15 One manual is shipped with each power sup ply Additional manuals may be purchased from your local Hewlett Packard field office see list at rear of this manual for addresses Specify the model number serial number prefix and stock number provided on the title page Table 1 1 INPUT 105 125Vac single phase 50 400Hz 0 294 28W OUTPUT 0 10Vdo 0 1A LOAD REGULATION Less than 4mV for a load current change equal to the current rating of the supply LINE REGULATION Less than 4mV for a change in line voltage from 103 5 to 126 5 or 126 5 to 103 5 at any output voltage and cur
56. ust R47 until front panel ammeter in dicates 6213A 1A 6215A 400mA 6217A 200mA 5 61 ZERO VOLTS OUTPUT ADJUSTMENT 5 62 To calibrate the output voltage so that there 5 13 Pointer R72 R6 or R8 R81 is zero volts output when the VOLTAGE controls are fully cow proceed as follows a Connect differential voltmeter between and output terminals b Short out voltage controls by connecting jumper across R10 and R11 c Turn on supply and observe reading on differential voltmeter d If it is more positive than 0 volts shunt resistor R5 with a decade resistance box e Adjust decade resistance until differen tial voltmeter reads zero then shunt R5 with re sistance value equal to that of the decade resist ance f lfreading of step c was more negative than 0 volts shunt resistor R7 with the decade re sistance g Adust decade resistance until differen tial voltmeter reads zero then shunt R7 with re sistance value equal to that of the decade resist ance 5 63 OUTPUT CURRENT LIMIT ADJUSTMENT 5 64 To adjust the limiting level of the output current proceed as follows a Attach the multimeter or a milliammeter to the output terminals of the supply Set the meter for approximately 600mA The internal resistance of the meter is low enough to overload the supply so that the output will current limit b Adjust the VOLTAGE controls fully clock wise c Adjust current limit control R50 for the follow
57. ut and therefore XL Zout 5 38 CURRENT LIMIT 5 39 To check the current limiting characteristics of the supply proceed as follows a Attach the multimeter or a milliameter to the output terminals of the supply Set the meter for approximately 600mA The internal resistance of the meter is low enough to overload the supply so that the output will current limit b Adjust the VOLTAGE controls fully clockwise c The meter should read as follows Model 6213A 1300 50mA 6215A 475 10mA 6217A 250 10mA 5 40 TRANSIENT RECOVERY TIME Definition The time X for output voltage recovery to within Y millivolts of the nominal output voltage following a Z amp step change in load current where Y is specified separately for each model but is generally of the same order as the load regulation specification The nominal output voltage is defined as the DO level half way between the static output voltage before and after the imposed load change and Z is the specified load current change normally equal to the full load current rating of the supply 5 41 Transient recovery time may be measured at any input line voltage combined with any output voltage and load current within rating 5 42 Reasonable care must be taken in switching the load resistance on and off A hand operated switch in series with the load is not adequate since the resulting one shot displays are difficult to observe on most oscilloscopes and the arc
58. utler Hammer Inc Lincoln Il General Electric Distributing Corp Schenectady N Y Miller Dial and Nameplate Co El Monte Calif Dale Electronics Inc Columbus Neb Elco Corp Willow Grove Pa Honeywell Inc Micro Switch Div Freeport Ill Sylvania Electric Prod Inc Semicon ductor Prod Div Woburn Mass Stevens Mfg Co Inc Mansfield Ohio Raytheon Co Components Div Industrial Components Operation Quincy Mass Tung Sol Electric Inc Newark N J Tru Ohm Products Memcor Components Div Huntington Ind Leecraft Mfg Co Inc Long Island City N Y Methode Mfg Co Chicago Ill Amphenol Controls Div of Amphenol Borg Electronics Corp Janesville Wis Sealectro Corp Mamaroneck N Y International Electronic Research Corp Burbank Calif Boston Mass 91345 91637 91662 91929 93332 93410 94144 94154 94310 95263 95354 96791 98291 98978 99934 Renbrandt Inc THE FOLLOWING H P VENDORS HAVE NO NUM BERS ASSIGNED IN THE LATEST SUPPLEMENT TO THE PEDERAL SUPPLY CODE FOR MANUFAC TURERS HANDBOOK Cooltron 00000 Plastic Ware Co Oakland Calif Brooklyn N Y C1 C2 4 6 8 13 O38 C5 c9 C10 114 C11 12 CIA CRI 2 CRI 5 6 8 9 12 CR4 CR7 CRIO 11 CR13 CR14 18 DSi Fl Q1 3 Q4 OB O6 8 10 Q7 Q9 Qli RI RZ R3 4 R5 R6 R7 R8 9 13 15 22 23 29 34 39 41 46 48 49 R10 R11 R12 R
59. ve emitter and base Output increases Remove jumper and proceed to Step 4 Check turnoff of Q5 by shorting x put remains Q5 R19 R20 defective Q4 emitter to collector increases Remove jumper and proceed to Step 5 Check conduction of Q4 by Output remains Stage Q4 defective shorting Q1 emitter to collector low Output increases Stage Q1 02 defective Check R10 R11 C1 for short and R12 for open Table 5 5 High Output Voltage Troubleshooting STEP ACTION RESPONSE PROBABLE CAUSE Turn the VOLTAGE control to ap proximately mid range and dis connect the load If the output voltage should rise to an exces sive value during the following procedure s the VOLTAGE control could be damaged if it is turned fully CCW 2 Check turnoff of Q7 by shorting Output remains high Q7 CR7 R20 defective Q5 emitter to collector Output decreases b Remove short across Q5 and proceed to Step 3 Check conduction of Q5 by removing Q4 collector lead Output remains high Stage Q5 defective b Replace Q4 collector lead and proceed to Step 4 b Output decreases Check turnoff of Q4 by shorting Q1 emitter to collector Output remains high Stage Q4 defective b Stage Q1 02 defective Check R10 R11 for open and R12 for short b Output decreases 5 53 REPAIR AND REPLACEMENT Table 5 6 which lists the special characteristics of selected semiconductors If the de
60. vice to be 5 54 Before servicing a printed wiring board refer replaced is not listed in Table 5 6 the standard to Figure 5 11 Section VI of this manual contains manufacturers part number listed in Section VI is a tabular list of the instruments replaceable parts applicable Before replacing a semiconductor device refer to Table 5 6 Selected Semiconductor Characteristics SUGGESTED REPLACEMENT REFERENCE p x DESIGNATOR CHARACTERISTICS PART NO Power NPN Silicon hfe 35 min I 4 Ampere 1854 0225 2N3055 R C A Vor 4 Volts Excessive heat or pressure can lift the copper strip from the board Avoid damage by using a low power soldering iron 50 watts maximum and following these instructions Copper that lifts off the board should be cemented in place with a quick drying acetate base cement having good electrical insulating properties A break in the copper should be repaired by soldering a short length of tinned copper wire across the break Use only high quality rosin core solder when repairing etched circuit boards NEVER USE PASTE FLUX After soldering clean off any excess flux and coat the repaired area with a high quality electrical varnish or lacquer When replacing components with multiple mounting pins suchas tube sockets electrolytic capa citors and potentiometers it will be necessary to lift each pin slightly working around the components several times until it is free WARNING If the specific
61. wer 6213A and 6214A 0 29A 28W 6215A and 6217A 0 258 25W 6216A and 6218A 0 25A 26W 2 17 CONNECTIONS FOR 230 VOLT OPERATION Figure 2 3 2 18 Normally the two primary windings of the input transformer are connected in parallel for op eration from 115 Volt source To convert the power supply to operation from a 230 Volt source the power transformer windings are connected in series as follows a Unplug the line cord and remove the top cover as described in Paragraph 5 3 b Remove the jumpers between taps 4 2 and 3 1 Solder a jumper between taps 3 2 on the input power transformer Tl see Figure 2 3 c Replace existing fuse with a 0 5 Ampere 230 Volt fuse d Replace existing line cord plug with a standard 230 Volt plug 2 19 POWER CABLE 2 20 To protect operating personnel the National Electrical Manufacturers Association NEMA recom mends that the instrument panel and cabinet be grounded This instrument is equipped with a three conductor power cable The third conductor is the ground conductor and when the cable is plugged TRANSFORMER PRIMARY CONNECTED FOR 11 VOLT OPERATION TRANSFORMER PRIMARY CONNECTED FOR 230 VOLT OPERATION j Figure 2 3 Input Power Transformer Connections into an appropriate receptacle the instrument is grounded The offset pin on the power cable three prong connector is the ground connection 2 21 To preserve the protection feature when oper ating the instrument from

HP 6213A User's Manual

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