DC Power Supply HP Model 6296A Operating and Service Manual

Page 2 - HP P/N 06296-90001 changes - continuedERRATAIn the parts list on page 6-5:Change C501 to HP P/N 0160-0710.Change C200 to fxd film .01 uF, 200 V,HP P/N 0160-0161.Change the listing for Q702, 800, 850, 852,853 to 2N2907A, Sprague 56289, HP P/I 1853-0099.·.change the part number for C803 to 0180-1986and its voltage rating to 85 V •. Add pilot light DSl HP P/N 1450-0566.Change SCR CR502 and CR504 from HP P/N 1884-0019 to P/N 1884-0347.ERRATAOn the schematic diagram, indicate tbat t.nominal value for R313 is 1 k. ThE! exa·value for R313 is factory selected to optimizethe range of transient adj\l.st potR307.In Appendix A, change Figure A-1 OvervoltageProtection Crowbar to appear as shown below:DC POWEii Sll'Pl.Y 62-...en ,Page 6-T:Add R865, var ww 250 ohm, HP P/N 2100-0439.Also add Spacer-round, HP P/N 0380-1551and Internal-external lockwasher, BP P/H2190-0576.Delete the two types of binding posts listand add the following:black binding post, HP P/N 1510-0114,qty. 2red binding post, HP P/N 1510-0115.Add: Insulator (CR502, 504), .HP P/H 5020-5595.For all instruments delivered on or afterJuly 1, 1978, change the HP P/N forfuseholder from 1400-0084 to fuseholder body2110-0564 and fuseh.o1der carrier 2110-0565.•On page 6-7:Change the HP P/N for fuseholder nut from2950-0038 to 2110-0569. If' old fuseholdermust be replaced for any reason, replacecomplete · fuseholder and nut with newfusebolder parts. Do not replace new partswith old parts.On page 6-8, note that effective January 1.1971, Options 007 (10-turn voltage control)and 008 (10-turn current control) are . nolonger available individually, but are stillavailable combined as Option 009. LikewiseOptions 013 (10-turn voltage control withdecadial) are · no longer available individually,but are available combined intoa single new option designated Option 015.Make these changes wherever Option 007 •. 008,013, or 014 is mentioned in the manual.•2

' Page 3 ·-HP P/N.06296-90001 changes - continuedCHANGE ·1Jaif:.. page 6-5, change C500 from 10,000 uF to~,000 uF, HP P/N 0180-1929. ·CHANGE 2On the component location drawing (schematicapron) make the following changes:a. Interchange collector (C) and emitter(E) designations for transistor Q853 onthe lower right hand side of drawing.b. Remove TP21 designation from R205 oncenter left hand side of drawing. TheTP21 designation at the bottom of R310is unchanged.c. TP19 (bottom center) should point tobottom of R300.d •. Interchange locations of Q401 and CR809at bottom left of drawing. Electricalconnections remain the same.CHANGE 3 .-The serial number prefix of the instrumenthas been changed from 6D to 70.the parts list and on the schematic, makee following changes: Add new resistor402, 600 ohm, 5 W, HP P/N 0811-1860 acrossR309 ( 150 ohm) • Change TSO 1 to HP P /N9100-2184.On the schematic, the primary of bias transformerT801 should be connected as shown inthe following sketch for 115 Vac operation.For 230 Vac operation, the jumpers betweenlugs 1 and 3, and 2 and 4 must be removed,and lugs 2 and 3 connected together. In addition,a new power transformer, TSOO, mustbe installed in accordance with Option 18.CHANGE 4Make the following changes in the partslist:Add new diode CR603, 1N485B, HP P/N 1901-0033.Change R313 to 1 k, 5% (selected) 1/2 W, HPP/N 0686-1025.Change R707 to 2 W, I.R.C. Type·BWH, HP P/N0811-1674.Change R601 to 422 ohm, 1/4 W, HP P/N 0698-11590.Change R870 to 5 k pot, HP P/N 2100-1824.Change R871 to 750 ohm, 11, HP P/N 0757-0420.Delete R872.Add new Zener diode VR800, 4.22 V, HP PIN1902-3070.Q-1 the schematic, delete ·R872 in the metercircuit and connect VR800 in its place. Theanode of VRSOO goes to base of Q850 andcathode goes to +15.4 V reference. Also,connect CR603 across VR600 in the referencecircuit. The anode of CR603 goes to +S andthe cathode goes to +9.4 volts.CHANGE 51lle serial number prefix of the instrumenthas been changed from 7D to 7M. In theparts list, delete S1 (switch/indicator,ON/OFF) and replace with a separate toggleswitch and pilot light as follows:51, toggle switch, Carling, 2FA53-73-SKI,HP P/N 3101-0984.DS1, pilot light, Neon, Sloan, HP P/N1450-0048. .Schematic connections to the new switch andpilot light remain the same except that thetwo are physcially separate.TIOI•3

Page 4 - HP P/N 06296-90001 changes - continued---------------------------------------------------------------------HP PART NO.DESCRIPTION :----------------------------------------------·: STANDARD l OPTION A85 OPTION X95----------------------:-------------:---------------:----------------Front Panel, Lettered : 06296-60004 06296-60001 :

..--;~age 5 - HP P/N 06296-9000·i changes - continuedNote: Due to the circuit changes shown.on~the next figure, it is no longer necessaryI~change any jumper connections at T801.dual primary windings of T801 are perentlywired in parallel across winding3-4 of T800. The pilot light, in series withR903, is also connected across th1 s winding.AC ~··~{AS-____ N·CHANGE 19 (Cont)lhe procedure for selecting R712 is identicalto the one given for 50 Hz operation inparagraph 5-55, steps g through j, exceptthat the resistance value should be selectedto ·provide a 3 V +/-.2 V drop across the·series regulator. (For 50 Hz operation, thevoltage drop across the series regulatorremains 3.5 V) Center R711 before using theresistance box to determine the value forR712 •.Also change VR600 to 9 V, HP P/N 1902-0785,change R606 to 9 k, HP P/N 698-5454, andchange R611 to 490 ohm, 3 W, HP P/N0811-1801.CHANGE 16In the parts list and on ~he schematic,change R307 to 10 k, 10S, HP P/N 2100-3210.CHANGE 17~the parts list and on the schematic, addcapacitor C901, 0.1 uF, 250 V. HP P/NN:.c----------016Q-~0.65 as shown below:F1C901·~~~-----------CHANGE 18In the parts list and on the schematic, addresistor· R904, 10 ohm, 5S, 1/2 W, HP P/N0686-1005 in series with the negative leadof capacitor C801.CHANGE 19~ the replaceable parts list and on the~atic, indicate that 12 k is the nominalvalue for R712. 1be value for R712 is factorys.elected to optimize the range of rampadjust pot R711.CIRCUIT PATENTS APPLIEDFOR LICENSE TO USE MUSTBE OBTAINED IN WRITING FROMHEWLETT-PACKARD CO.HARRISON DIVISION.NOTES:1. All resistors are in ohms, 1/2W, +5$uness otherwise noted.2. All capacitors are in microfaradsunless otherwise noted.CHANGE 20In the parts. list and on the schematic forthe overvoltage protection crowbar, deleteR1 and VR1; add U1 voltage regulator, HP P/N1826-0276 and C2, fxd elect, 1 uF, 50 V, HPPlN 0180-0230; and change R9 to 1.5 k, HPP/N 0757-0427 and R10 to 1.5 k, 5$, HP P/N0811-1805 as shown in the schematic.below:""'"' sCZ•+l~.411~5

Page 6 - HP PIN 06296-90001 changes - continued•CHANGE 21In the replaceable parts list, change the HPPIN's for the binding posts and associa~edhardware to the following: Red binding post,qty. 2, 1510-0091; Terminal lug, qty. 2,0360-0042; Lockwasher, qty. 2, 2190-0079;Nut, qty 2, 2500-0001; .Black binding post,qty 1, 1510-0107;·'· Terminal lug, qty. 1,0360-1190; Nut, qty. 3, 2950-0144..CHANGE 22In the replaceable parts list on page 6-7,change S1 (previously changed in Change 5)to HP PIN 3101-2456. On page 6-5, change Q40to HP PIN 1854-0458.CHANGE 23• 'fllis change also applies to units withserial numbers 2114A-4177; 4190, and 4240.In the replaceable parts list and on theschematic for the overvoltage protectioncrowbar, make the following changes: ChangeC2 (added in Change 20) to 2.2 uF, 20 V, HPPIN 0180-0155.Add C3, fxd cer, 0.01 uF, 10S, 100 V, HP PIN0160-4832. . It is to be mounted between thecathode or CR1 and the anode of CR2.Change CR4 to a two junction stabistor, HPPIN 1901-0701.CHANGE 24In the replaceable parts list on page 64),change R605 to 6.8 k, HP PIN 0757-0750.CHANGE 25CHANGE 27In the replaceable parts list, change th.part number for the bias transformer from HP/N 9100-2184 to HP P/N 9100-4751. Notethat the primary wiring colors have changed,the white/grey is now black/yellow a1:ld thegrey is now black. See the figure below.For 115 v.c 0Pltl11on··-..Figure 28a • Transformer Q:innec:tions- ~--~:y~-~ =---... ,........ '-··-·~CHANGE 28In the replaceable parts list, change~ Q40.from HP P/N 1854-1124 to HP PIN 1854-0!158.CHANGE 29In the replaceable parts list, change thepart number for Q851 from HP PIN 185!~-0221to HP PIN 1854-0229.CHANGE 30In the replaceable parts list, change! Q400to HP PIN 06296-80004. Use this part r.tumberfor replacement on all units.In the replaceable parts list, page 6-7 addthe following mechanical assembly; BarrierStrip Guard Assembly HP .PIN 5060-2862, qty1.CHANGE 26In the replaceable parts list, page 6-5,change Q400 to HP P/N 1854-1124 QTY 1, andQ303 to HP P/N 1854-1017.•6

•••SAFETY SUMMARYThe following general safety precautions must be observed during all phases of operation, service, and repair of this instrument.Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of dnign,manufacture, and intended use of the instrument. Hewlett-Packllrd Company assumes no liability for the customer's failure tocomply with these requirements.BEFORE APPLYING POWERVerify that the product is set to match the available line voltage.GROUND THE INSTRUMENTThis product is a Safety Class 1 instrument (provided with aprotective earth terminal). To minimize shock hazard, theinstrument chassis and cabinet must be connected to anelectrical ground. The instrument must be connected to the acpower supply mains through a three-conductor power cable,with the third wire firmly connected to an electrical ground(safety ground) at the power outlet. Any interruption of theprotective (grounding! conductor or disconnection of theprotective earth terminal will cause a potential shock hazardthat could result in personal injury. If the instrument is to beenergized .via an external autotransformer for voltage reduction,be certain that the autotransformer common terminal isconnected to the neutral !earthed pole) of the ac power lines(supply mains!. This instrument is equipped with a line filter·to reduce electromagnetic interference (EMii, and must beconnected to a property grounded receptacle to minimize EMI.FUSES ·Fuses are contained inside the unit, and are not userreplaceable.Only trained service personnel should replace blownfuses, and only after identifying and correcting the problemwhich caused the fuse(s) to blow.DO NOT OPERATE IN AN EXPLOSIVEATMOSPHEREDo not operate the instrument in the presence of flammablegases or fumes.KEEP AWAY FROM LIVE CIRCUITSOperating personnel must not remove instrument covers.Component replacement and internal adjClstments must bemade by qualified service pei-sonnel. Do not replace componentswith the power cable connected. Under certain conditions,dangerous voltages may exist even with the power cableremoved. To avoid injuries, always disconnect power, dischargecircuits and remove external voltage sources before touchingcomponents.DO NOT SERVICE OR ADJUST ALONEDo not attempt internal service or adjustment unless anotherperson, capable of rendering first aid and resuscitation, ispresent.DO NOT EXCEED INPUT RATINGSOperation at line voltages or frequencies in excess of thosestated on the data plate may cause leakage currents in excess of3.5 mA peak .SAFETY SYMBOLSInstruction manual symbol: the product willbe marked with this symbol when it isnecessary for the user to refer to theinstruction manual (refer to Table ofContents).Indicates hazardous voltages.@ or .I. Indicate earth (ground) terminal.orWarning0(CAUTION!orCautionIThe WARNING sign denotes a hazard. Itcalls attention to a procedure, practice, orthe like, which, if not correctly performedor adhered to, could result in personalinjury. Do not proceed beyond aWARNING sign until the indicatedconditions are fully understood and met.The CAUTION sign denotes a hazard. Itcalls attention to an operating procedure,or the like, which, if not correctlyperformed or adhered to, could result indamage to or destruction of part or all ofthe product. Do not proceed beyond aCAUTION sign until the indicatedconditions are fully understood and met.DO NOT CIRCUMVENT SAFETY DEVICESAC mains power exists on exposed terminals in various locationsin the mainframe and on the load modules. To protect the useragainst the danger of electric shock, the unit is equipped witha safety interlock that removes ac mains power when the topcover is removed. Do not attempt to defeat the function of thesafety interlock.DO NOT SUBSTITUTE PARTS OR MODIFYINSTRUMENTBecause of the danger of introducing additional hazards, do notinstall substitute parts or perform any unauthorized modificationto the instrument. Return the instrument to a Hewlett-PackardSales and Service Office for service and repair to ensure thatsafety features are maintained.Instruments which appear damaged or defective should be made inoperative and sscured against unintended operation unril theycan be repaired by qualified service personnel.

TABLE OF CONTENTS•Section Page No. Section Pa~1e No.I GENERAL INFORMATION 1-1 IV PRINCIPLES OF OPERATION1-l DescriptiOn 1-1 4-8 Simplified Schematic 'l-31-6 Specifications 1-1 4-10 Detailed Circuit Analysis 4-31-8 Options 1-1 4-11 Preregulator and Control Circuit•l-31-10 Accessories 1-2 4-19 Series Regula tor •l-51-12 Instrument Identification 1-2 4-21 Constant Voltage Input Circuit 4 1-51-15 Ordering Additional Manuals 1-2 4-26 ConstantCurrent Input Circuit •l-64-31 Gating Circuit

•SECTION IGENERAL INFORMATION••1-1 DESCRIPTION1-2 This power supply is completely transistorizedand suitable for either bench orrelay rack operation. It is a compact, well-regulated.Constant Voltage/ Constant Current supplythat will furnish full rated output voltage at themaximum rated output current or can be conUnuous-1 y adjusted throughout the output range. The frontpanel CURRENT controls can be used to establishthe output current limit (overload or shon circuit)when the supply is used as a constant voltagesource and the VOLTAGE control can be uaed toestablish the voltage limit (ce1Ung) when the supplyis used as a constant current source. Thesupply will automatically crossover from constantvoltage to constant current operation and Viceversa if the output CUITant or voltage exceeds thesepreset limits.1-3 The power supply has both front and rearterminals. Either the positive or negative outputterminal may be qrounded or the power supply canbe operated floating at up to a maximum of 300volts off ground.1-4 A single meter is used to measure either outputvoltage or output current in one of two ranges.The voltage or current ranges are selected by aMETER switch on the front panel.1-S Barrier strip terminals located at the rear ofthe unit allow ease in adapting to the many operationalcapabiUU~s of the power supply. A briefdescription of these capabilities is given below:a. Remote ProgrammingThe power supply may be programmedfrom a remote location by means of an externalvoltage source or resistance.b. Remote SensingThe degradation in regulation whichwould occur at the load because of the voltagedrop in the load leads can be reduced by using thepower supply in the ·remote sensing mode of operation.c. Series and Auto-Series OperationPower supplies may be used in serieswhen a higher output voltage is required in thevoltage mode of operation or when greater voltagecompliance is required in the constant currentmode of operation. Auto-Series operation permitsone knob control of the total output voltage from a"master" supply.d. Parallel and Auto-Parallel QperationThe power supply may be operated inparallel with a similar unit when greater outputcurrent capability is required. Auto-Parallel operationpermits one knob control of the total outputcurrent from a "master" supply.e. Auto-Track1n9The power supply may be used as a"master" supply. havin9 control over one (ormore) "slave" supplies that furnish variousvoltages for a system.1-6 SPECifJCATIONS·1-7 Detailed specifications for the power supplyare given in Table 1-1.i-s omoNS1-9 Options are factory modifications of astandard instrument that are requested by thecustomer. The follOWirlCJ options are availablefor the instrument covered by this manual.Where necessary. detailed covera9e of the optionsis included throughout the manual.Option No.OSDescriptionSO Hz Regulator Realignment:Standard instruments will operatesaUsfactorily at both 60 and 50 Hzwithout adjustment. However Option05 factory reall9nment resultsin more efficient operation at 50 Hz,and is recommended for all applicationswhen continuous operation froma SO Hz ae input is intended .1-1

Option No.Descriptionc:lres ses).0708Voltage 10-Tum Control: A singlecontrol that replaces both coarse andfine voltage controls and improvesoutput settability.Current l '7'-Turn Control: A singlecontrol that replaces both coarse andfine current controls and improvesoutput settablllty.i Part No.14SlSA1452SADescriptionRack Kit for mounting one Si"high supply. (Refer to Section IIfor details. )Rack Kit for mounting two Si"high supplies. (Refer to Section IIfor details. )•09111314181-10 ACCESSORIESVoltage and Current 10-Tum Controls:Options 07 and 08 on sameinstrument.Intema 1 Overvoltage Protection"Crowbar". Operating and Serviceinformation is included 1n Appendix Aat the rear of the manua 1.Three Digit Graduated DecadialVoltage Control: Control that replaces10-tum voltage control permittingaccurate resettability.Three Digit Graduated DecadialCurrent Control: Control that replacescoarse and fine current controlspermitting accurate resettability.230V AC, Single Phase, Input:• Supplyis shipped for llSV ac operation.Option 18 consists of modifying thesupply for 230Vac operation.1-11 The accessories listed in the followingchart may be ordered with the power supply orseparately from your local Hewlett-Packard fieldsales office (refer to list at rear of manual for ad-1-12 INSTRUMENT IDENTIFICATION1-13 Hewlett-Packard power supplies are identifiedby a three-part serial number tag. The firstpart is the power supply model number. The i;econdpart is the serial number prefix, which co•nsistsof a number-letter combination that denc>testhe date of a significant design change. The numberdesignates the year, and th,e letter A through Mdesignates the month, January.through Decemberrespectively. The third part is the power supplyserial number.1-14 If the serial number prefix on your powersupply does not agree with the prefix on the titlepage of this manual, change sheets are includedto update the manual. Where applicable, bac:kdatinginformation is given in an appendix at therear of the manual.1-lS ORDERING ADDITIONAL MANU~1-16 One manual is shipped with each powersupply. Additional manuals may be purchasedfrom your local Hewlett-Packard field office (seelist at rear of this manual for addresses). Specifythe model number, serial number prefix, and G~stock number provided on the Utle page.••1-2

•INPUT:OUTPUT:105-125 VAC. single phase, 50-60Hz,4. SA, 250W •0-60 volts@ 0-3 amps.LOAD REGULATION:Constant Voltage -- Less than 0. 01% plusl mV for a full load to no load change in outputcurrent.Constant Current -- Less than 0. 05% pluslmA for a zero to maximum change in outputvoltage.Table 1-1. Specificationsincluding a direct short placed across the terminalsin constant voltage operation, The constantvoltage circuit limits the output voltage in theconstant current mode of operation.METER:The front panel meter can be used as eithera 0-70 or 0-7 volt voltmeter or as a 0-4 or 0-0. 4amp ammeter.OUTPUT CONTROLS:Coarse and fine voltage controls and coarseand fine current controls provide continuous adjustmentover the entire output span.••LINE REGUIATION:Constant Voltage -- Less than 0. 01% pluslmV for any line voltage change within the inputrating.Constant Current -- Less than O. 05% pluslmA for any line voltage change within the inputrating,RIPPLE AND NOISE:Constant Voltage -- Less than 500t£V rms.Constant Current -- Less than 3mA nns.OPERATING TEMPERATURE RANGES:Operating: o to sooc. Storage: -20 to +ssoc.TEMPERATURE COEFFICIENT:Constant Voltage -- Less than O. 02% plusS0011V ?er degree Centigrade.Constant Current -- Less than O. 02% plusl. 5mA per degree Centigrade.STABILI'IY:Constant Voltage -- Less than 0.10% plus2. 5mV total drift for 8 hours after an initial warmuptime of 30 minutes at constant ambient. constantline voltage. and constant load.Constant Current -- Less than O. 10% plus7. SmA total drift for 8 hours after an initial warmuptime of 30 minutes at constant ambient, constantline voltage, and constant load.INTERNAL IMPEDANCE AS A CONSTANT VOLTAGESOURCE:Less than O. 001 ohm from DC to lOOHz.Less than O. 01 ohm from lOOHz to lkHz.Less than 0. 2 ohm from lkHz to lOOkHz.Less than 2. 0 ohms f~m l 00 kHz to 1 MHz.TRANSIENT RECOVERY TIME:Less than 50~sec for output recovery to within15 mv following a current change in the outputequal to the current rating of the supply or 5amperes, whichever is smaller •OVERLOAD PROTECTION:A continuously acting constant current circuitprotects the power supply for all overloads1-3OUTPUT TEINALS:Three "five-way" output posts are providedon the front panel and an output terminal strip islocated on the rear of the chassis. .All powersupply output terminals are isolated from thechassis and either the positive or negative terminalmay be connected to the chassis through aseparate ground terminal. If the front panel terminalsare used. the load regulation will be O.SmVper ampere greater. due to the front terminal resistance.ERROR SENSING:Error sensing is normally accomplished atthe front terminals if the load is attached td thefront or at the rear terminals if the load is attachedto the rear terminals. Also. provision is includedon the rear tenainal strip for remote sensing.REMOTE PROGRAMMING:Remote programming of the supply output atapproximately 300 ohms per volt in constant voltageis made available at the rear terminals. Inconstant current mode of operation. the currentcan be remotely programmed at approximately500 ohms per ampere.COOLING:Convection cooling is employed. The supplyhas no moving parts.SIZE:5}" H x 16" D x Si" W. Two of the unitscan be mounted side by side in a standard 19"relay rack.WEIGHT:29 lbs. net. 38 lbs. shipping.FINISH:Light gray front panel with dark. gray case.POWER CORD:A three-wire, five-foot power cord is providedwith each unit.

•IQ ti0....0 c0 •r-¥0L.TACE-,C.OAAS( r1-.[(j (j10 .1Icl QFigure 2-2. Rack Mounting, One Unit2-14 To mount a single unit in the rack panel,proceed as follows:a. Bolt rack mounting ears. combiningstraps, and angle brackets to each side of centerspacing panels. Angle brackets are placed behindcombining straps as shown in Figure 2-2.unit.b. Remove four screws from front panel ofc. Slide combining strips between frontpanel and case of unit.d. Bolt angle brackets to front sides ofcase and replace front panel screws.2-15 INPUT POWER REQUIREMENTS2-16 This power supply may be operated fromeither a nominal 115 volt or 230 volt 50-60 cyclepower source. The unit, as shipped from the factory,is wired for 115 volt operation only. Afactory modification (Option 18) must be made topermit operation from a 230 volt line. The inputpower required when operated from a llS volt, 60cycie power source at full load is given in thes~ecification table in Section I.2-17 SO Hz OPERATION2-18 Theunit as normally shipped from the factorycan be operated from either a 50 or 60 Hz source.However, with a 50 Hz input, the operation of theunit may become somewhat deqraded when thetemperature exceeds 350 Centigrade (instead of thenormal soocentigrade capability with a 60 Hz input).To permit optimum operation at 50 Hz, the unit mustbe realigned. This realignment procedure is describedin Paragraph 5-54 at the rear of the·manual.2-19 POWER CABLE2-20 To protect operating gersonnel, the NationalElectrical Manufacturers' Association (NEMA)recommends that the instrument panel and ca:binetbe grounded. This in&trument is equiPped with athree conductor p01Ner cable. The third cond·uctoris the ground conductor and when the cable is •plugged into an appropriate receptacle, the instrumentis grounded. The offset pin on the powercable three-prong connector is the ground connection.2-21 To preserve the protection feature when operatingthe instrument from a two-contact outlet,use a three-prong to two-prong adapter and c:onnectthe green lead on the adapter to ground.2-22 REPACKAGING FOR SHIPMENT2-23 To insure safe shipment of the instrument,it is recommended that the package designed forthe instrument be used. The original packagingmaterial is reusable, If it ls not available, contactyour local Hewlett-Packard field office ~:oobtain the materials. This office will also furnishthe address of the nearest service office to whichthe iT\strument can be shipped. Be sure to attacha tag to the instrument which specifies the o·wner,model number, full serial number, and SE~rvicerequired, or a brief description of the troublE!.•2-2

•3-1 OPERATING CONTROLS AND INDICATORS3-2 The front panel controls and indicators, togetherwith the normal turn-on sequence, areshCM'n in Figure 3-1.ll(f(ISECTION IIIOPERATING INSTRUCTIONS03-5 NORMAL OPERATING MODE3-6 The power supply is normally shipped withits rear terminal strapping connections arrangedfor Constant Voltage/Constant Current, localsensing, local programming, single unit mode ofoperation. This strapping pattern is illustrated inFigure 3-2. The operator selects either a constantvoltage or a constant current output using the frontpanel controls Oocal programming, no strappingchanges are necessary}.••TURN-ON SEQUENCEI. PUSH ON/OFF BUTTON ANO BUTTON SHOULO LIGHT.2. SET METER SWITCH TO C&SIREO VOLTAGt llAN'GE.3. ADJUST COARSE AND nNE VOLTAGE CONTROLS UNTIL lXSllEDOUTPUT VOLTAGE IS INOICATl:D ON METER •~. SET METER SWITCH DESIRED CURRENT ltANGt AND SHORT CIR•CUIT OUTPUT TERMINALS.s. ADJUST CURRENT CONTROLS f'OR cc;nu;o OUTPUT ci.nuu:m.~. R.CMOV!: SHORT AND CONNECT ~TO OUTPUT TERMINALSll'RONT OR REAR!.Figure 3-1. Front Panel Controls and Indicators3-3 OPERAnNG MODES3-4 The power supply is desiqned so that itsmode of operation can be selected by makingstrapping conne~tions between particular terminalson the terminal strip at the rear of the power supply.The terminal designations are stenciled inwhite on the power supply above their respectiveterminals. Although the strapping patterns Ulustratedin this section show the positive terminalgrounded, the operator can ground either terminalor operate the power supply up to 300 vdc offground (floating). The following paragraphs describethe procedures for utilizing the variousoperational capabilities of the power supply. Amore theoretical description concerning the operationalfeatures of this supply is contained in apower supply Application Manual and in variousTech. Letters published by the Harrison Division.Copies of these can be obtained from your localHewlett-Packard field office.Figure 3-2. Normal Strapping Pattern3-7 CONSTANT VOLTAGE3-8 To select a ronstant voltage output, proceedas follows:a. Turn-on power supply and adjustVOLTAGE controls for desired output voltage {outputterminals open).b. Short output terminals and adjust CUR­RENT controls for maximum output current allowable(current limit), as determined by load conditions.If a load change causes the current limit tobe exceeded, the power supply will automaticallycrossover to constant current output at the presetcurrent limit and the output voltage will drop proportionately,In setting the current limit, allowancemust be made for high peak current which cancause unwanted cross-over. (Refer to Paragraph3-46).3-9 CONSTANT CURRENT3-10 To select a constant current output. proceedas follows: ·a. Short output terminals and adjust CUR­RENT controls for desired output current.3-1

. Open output terminals and adjustVOLTAGE controls for maximum output voltage allowable(voltage limit), as determined by loadconditions. If a load change causes the voltagelimit to be exceeded, the power supply will automaticallycrossover to constant voltage output atthe preset voltage limit and the output current willdrop proportionately. In setting the voltage limit,allowance must be made for high peak voltageswhich can cause unwanted crossover. (Refer toParagraph 3-46).NOTEWhen Model 6291A is operated continuously in thecrossover region. between Constant Voltage/ConstantCurrent, the feedback loop may break into oscillation;particularly in the 0. SA to l. SA outputcurrent range. Although the crossover region is notusually an area of continuous operation, this problemcan be eliminated, if necessary, by connectingthe emitter of Q300 to +S (instead of to the emitterof Q301) and readjusting R307. Note that when thisis done, the transient recovery time of Model 6291Amust be derated to "SOµsec for recovery to within25mV" (instead of lSmV).3-11 CONNECTING LOAD3-16 OPTIONAL OPERATING MODES3-17 REMOTE PROGRAMMING, CONSTANT VOl~T­AGE3-18 The constant voltage output of the powersupply can be programmed (controlled) from aremote location if required. Either a resistance orvoltage source can be used for the programmingdevice. The wires connecting the programmingterminals of the supply to the remote programmir1gdevice should be twisted or shielded to reducenoise pick-up. The VOLTAGE controls on thefront panel are disabled according to the followi.ngprocedures.~ ~ ~ +· + G - - ~ ~ M M M ~ M1°1~1~1PROGRAMMINGRESISTatFigure 3-3. Remote Resistance Programming(Constant Voltage)•3-12 Each load should be connected to the powersupply output terminals using separate pairs ofconnecting wires. This will minimize mutual couplingeffects between loads and will retain fulladvantage of the low output impedance of thepower supply. Each pair of connecting wiresshould be as short as possible and twisted orshielded to reduce noise pickup. (If shield isused, connect one end to power supply groundterminal and leave the other end unconnected. )3-13 If load considerations require that the outputpower distribution terminals be remotelylocated from the power supply, then the powersupply output terminals should be connected tothe remote distribution 'terminals via a pair oftwisted or shielded wlres and each load separatelyconnected to the remote distribution terminals.For this case. remote &ensing should be used{Paragraph 3-30).3-14 OPERATION OF SUPPLY BEYOND RATEDOUTPUT3-15 The shaded area on the front panel meterface indicates the amount of output voltage orcurrent that is available in excess of the normaloutput. Althouoh the supply can be operated inthis shaded region without being damaged, it cannotbe guaranteed to meet all of its performancespecifications. Hawever, if the line voltage ismaintained above 115 Vac, the supply wil~probablyoperate within its specifications.3-19 Resistance Programming (Figure 3-3). Inthis mode. the output voltage will vary at a ratedetermined by the programming coefficient, 200 •ohms per volt (300 ohms per volt for Model 6296A).The output voltage will increase l volt for each200 ohms (or 300 ohms) added in series with theprogramming terminals. The programming coeffi--cient is determined by the pr09rammin9 current.This current is factory adjusted to within 2% ofS ma (2% of 3. 3 ma for Model 6296A). If greaterprogramming accuracy is required, it may beachieved by changing resistor R806.3-20 The output voltage of the power supplyshould be zero volts z20 millivolts when zeroohms is connected across the programming termi·­nals.3-21 To maintain the stability and temperaturecoefficient of the power supply, use programmin~;resistors that have stable, low noise, and lowtemperature (less than 30 ppm per degree Centigrade)characteristics. A switch can be used inconjunction with various resistance values in orderto obtain discrete output voltages. The switchshould have make-before-break contacts to avoidmomentarily opening the programming terminalsduring the switching interval.3-22 Voltage Programming (Figure 3-4). Employthe strapping pattern shown on Figure 3-4 for . •voltage programming. In this mode, the outputvoltage will vary in a 1 to 1 ratio with the pro-3-2

•••;ramming voltage (reference voltage) and the loadon the programming voltage source will not exceed25 microamperes.Al 46 A2 + + G - - •S AJ A4 AS A6 A7 Al101~1r1m1VOLTAGESOURCEFigure 3-4. Remote Voltage Programminq(Constant Voltage)3-23 The impedance matching resistors (Rx) forthe programming voltage source should be approximately1000 ohms to maintain the temperature andstability specifications of the power supply.3-24 REMOTE PROGRAMMING, CONSTANT CUR­RENT3-25 Either a resistance or a voltage source canbe used to control the constant current output ofthe supply. The CURRENT controls on the frontpanel are disabled according to the following procedures•PROGRAMMINGlu:slStoRFiqure 3-S. Remote Resistance Programming(Constant .Current)3-26 Resistance Pn?qrammins (Figure 3-5). Inthis mode, the output current varies at a ratedetermined by the programming coefficient -- 100ohms per ampere for Models 6282A and 6286A, 200ohms per ampere for Models 6285A and 6291A, and500 ohms per ampere for Models 6290A and 6296A.The programming coefficient ls determined by theConstant Current programming current l mA forModels ~282A, 6285A, 6286A, and 6291A or O. 66mA for Models 6290A and 6296A. This current isadjusted to within 10% at the factory. If qreaterprogramming accuracy is required, it may beachieved by changing resistor R808 as outlined inSection V.3-27 Use stable, low noise, low temperature coefficient(less than 30 ppm/Oc) programming resistorsto maintain the power supply temperature3-3coefficient and stability specifications. A switchmay be used to set discrete values of output current.A make-before-break type of switch shouldbe used since the output current will exceed themaximum rating of the power supply if the switchcontacts open during the switching interval.CAUTIONIf the programming terminals (Al and A7) shouldopen at any time durinq this mode, the output currentwill rise to a value that may damage the powersupply and/or the load. To avoid this possibility,connect a lK resistor (1. SK for Models 6290A and6296A) across the programming terminals. Like theprogramming resistor, this resistor should be of thelow noise, low temperature coefficient type,3-28 Voltage Programming (Figure 3-6). In thismode. the output current will vary linearly withchanges in the programming voltage. The programmingvoltage should not exceed 1. 5 volts.Voltage in excess of 1. 5 volts will result in excessivepower dissipation in the instrument andpossible damage,VOLtACESOURCEFigure 3-6. Remote Voltage Programming(Constant Current)3-29 The output current will be the programmingvoltage divided by the internal current samplingresistance RSOO. The current required from thevoltage source will be less than 10 microamperes.The impedance matching resistor (Rx) should beapproximately 1000 ohms if the temperature coefficientand stability specifications of the powersupply are to be maintained.3-30 REMOTE SENSING (See Figure 3-7)3-31 Remote sensing is used to maintain goodregulation at the load and reduce the degradationof regulation which would occur due to the voltagedrop in the leads between the power supply andthe load. Remote sensing is accomplished byutilizing the strapping pattern shown in Figure3-7. The power supply should be turned off beforechanging strapping patterns. It is not required

that these leads be as heavy as the load leads.However, they must be twisted or shielded tominimize noise pick-up.r"Al"""'l"'--r~r--.,..-..,.;;;...----....-..--.....-..,.;.;;~A6.;;.,.;117 U~~~~c@0•Fiqure 3-7. Remote SensingFigure 3-8. Normal Series Connectii:>nsCAUTIONObserve polarity when connectingthe sensing leads to the load.3-32 Note that it is desirable to minimize thedrop in the load leads and it is recommended thatth~ drop not exceed 1 volt per lead if the powersupply is to meet its DC specifications. If alarger drop must be tolerated, please consult aHewlett-Packard field representative.NOTEDue to the voltage drop in the loadleads, it may be necessary to readjustthe current limit in the remotesensing mode.3-33 The procedure Just described will result in alow DC output impedance at the load. If a low ACimpedance is required, it is recommended that thefollowing precautions be taken:a. Disconnect output capacitor C803 bydisconnecting the strap between A2 and +s.b. Connect a capacitor having similar characteristics(approximately same capacitance, samevoltage rating or greater, and having good highfrequency characteristics) across the load·usingshort leads,is used, the output voltage is the sum of thevoltaqes of the individual supplies. Each: of theindividual supplies must be adjusted in oz'der toobtain the total output voltage. The powe·r supplycontains a protective diode connected int~!mallyacross the output which protects the supply if onepower supply is turned off while its serie:; partner(s)is on.3-37 Auto-Series Connections (Figure 3-~ll.. TheAuto-Series configuration is used when it is desirableto have the output wltage of each of theseries connected supplies vary in accordc1nce withthe setting of a control unit. The control unit iscalled the master; the controlled units arE! calledslaves. At maximum output voltage, the voltageof the slaves is determined by the setting of thefront panel VOLTAGE control on the mastei~. Th.master supply must be the most positive supplythe series. The output CURRENT controls of allseries units are operative and the current limit isequal to the lowest control setting. U any outputCURRENT controls are set too low, automaticcrossover to constant current operation wl.11 occurand the output voltage will drop, Remote sensingand programming can used: however, the strappingarrangements shown in the applicable fig1J.res showlocal sensing and programming.Al0 MASTER3-34 Although the strapping patterns shown inFigures 3-3 through 3-6 employ local sensing,note that it is possible to operate a power supplysimultaneously in the remote sensing and ConstantVoltage/Constant Current remote proqrammingmodes.3-35 SERIES OPERATION3-36 Normal Series Connections (Figure 3-8).0 St.\VEAlTwo or more power supplies can be operated inseries to obtain a higher voltage than that availablefrom a single supply. When this connectionFigure 3-9. Auto-Series, Two Units•3-4

••3-38 In order to maintain the temperature coefficientand stability specifications of the pc)wersupply, the external resistor (Rx) shown in Figure3-9 should be stable, low noise, low temperaturecoefficient (less than 30 ppm per degree Centigrade)resistors. The value of this resistor isdependant on the maximum voltage rating of the"master" supply. The value of Rx is this voltagedivided by the voltage programming current of theslave supply (l/Kp where Kp is the voltage programmingcoefficient). The voltage contribution ofthe slave is determined by its voltage control setting.3-39 PARALLEL OPERATION3-40 Normal Parallel Connections (Figure 3-10).Two or more power supplies can be connected inparallel to obtain a total output current greaterthan that available from one power supply, Thetotal output current is the sum of the output currentsof the individual power supplies. The outputCURRENT controls of each power supply can beseparately set. The output voltage controls of onepower supply should be set to the desired outputvoltage: the other power supply should be set fora slightly larger output voltage. The supply set tothe lower output voltage will act as a constantvoltage source: the supply set to the higher outputwill act as a constant current source, dropping itsoutput voltage until it equals that of the othersupply. The constant voltage source will deliveronly that fraction of its total rated output currentwhich is necessary to fulfill the total currentdemand.Figure 3-11. Auto-Parallel. Two Unitsto the master's regardless of the load conditions.Because the output current controls ot each slaveare operative, they should be set to maximum toavoid having the slave revert to constant currentoperation: this would occur if the master outputcurrent setting exceeded the slave's.3-42 AUTO-TRACKING OPERATION (See Figure3-12)St.Avt•MASTER MUST Bl: MOST FOS111VE SUPPLYFigure 3-12. Auto-Tracki~g, Two Units•Figure 3-10. Normal Parallel Connections3-41 Auto-Parallel. The strapping patterns forAuto-parallel operation of two power supplies areshown in Figure 3-11. Auto-Parallel operationpermits equal current sharing under all load conditions,and allows complete control of outputcurrent fron:i one master power supply. The outputcurrent of each slave will be approximately equal3-S3-43 The Auto-Tracking configuration is usedwhen it is necessary that several different voltagesreferred to a common bus, vary in proportionto the setting of a particular instrument (the controlor master). A fraction of the master's outputvoltage is fed to the comparison amplifier of theslave supply, thus controlling the slave's output.The master must have the largest output voltage ofany power supply in the group (must be the mostpositive supply in the·example shown on Figure3-12).

3-44 The output voltage of the slave is a percentageof the master's output voltage, and is determinedby the voltage divider consisting of Rx andthe voltage control of the slave supply, Rp. where:Es= Rp/Rx + Rp. Tum-on and tum-off the powersupplies is controlled by the master. Remotesensing and programming can be used; although thestrapping patterns for these modes show only localsensing and programming. In order to maintain thetemperature coefficient and stability specificationsof the power supply, the external resistors shouldbe stable, low noise, low temperature (less than30 ppm per 0 c) resistors.3-45 SPECIAL OPERATING CONSIDERATIONS3-46 PULSE LOADING3-47 The power supply will automatically crossover from constant voltage to constant current operation,or the reverse, in response to an increase(over the preset limit) in the output current or voltage,respectively. Although the preset limit maybe set higher than the average output current orvoltage. high peak currents or voltages (as occurin pulse loading) may exceed the preset limit andcause crossover to occur. If this crossover limitingis not desired, set the preset limit for thepeak requirement and not the average.3-48 OUTPUT CAPACITANCE3-49 An internal capacitor, connected across theoutput terminals of the power supply, helps to supplyhigh-current pulses of short duration duringconstant voltage operation. Any capacitance addedexternally will improve the pulse current capability,but will decrease the safety provided by the constantcurrent circuit. A high-current pulse maydamage load components before the· average outputcurrent is large enough to cause the constant cur­-rent circuit to operate.3-50 The effects of the output capacitor during •constant current operation are as follows:a. The output impedance of the power supplydecreases with increasing frequency.b. The recovery time of the output voltage islonger for load resistance changes.c. A large surge current causing a high powerdissipation in the load occurs when the load resistanceis reduced rapidly.3-51 REVERSE VOLTAGE LOADING3-52 A diode is connected across the output terminals.Under normal operating conditions, thediode is reverse 'biased (anode connected to negativeterminal). If a reverse voltage is applied tothe output terminals (positive voltage applied tonegative terminal), the diode will conduct, shuntingcurrent across the output terminals an1d limitingthe voltage to the forward voltage drop of thediode. This diode protects the series transistorsand the output electrolytic capacitor.3-5 3 REVERSE CURRENT LOADING3-54 Active loads connected to the poweir supplymay actually deliver a reverse current to the P°"'tAsupply during a portion of its oper~ting C}'Cle. A19external source cannot be allowed to pump currentinto the supply without loss of regulation and possibledamage to the output capacitor. To avoidthese effects, it is necessary to preload the supplywith a dummy load resistor so that thei powersupply delivers current through the entire operatingcycle of the load device.•3-6

••TBIASIRECTIFIER/AC FOWDMOTE:TRANS TORM DIHR£1'£RENCECIRCUITr--- REFERtNCEVOLTAGES8JAS-SUPPLY -VOLTAGES-PllEREGUIJI....DENOTES VOLTAGEFEECIACl PATH--- DENOTES CURRENTFtEDIACl MTHI.lOR,nLTER- COtmlOLSCACJllCUJT'SECTION IVPRINCIPLES OF OPERATION•--~SERIESREGULATOR"ERROiiL

PIOTIOI 8CHOOJ - - •1~4V~. UGtll-'TOaIEFEllENCE•9.fVctoo::: 0600 THlUl"'I 0503 _ •6.2V.....--. • CHOI"-.I~CllOO •YOLt!I2 uCUlllENT(NOU 2)INPUT- J...- CIRCUIT0200• l>-U~HO~... CIOO: ~I15 Cl!_80lACC I TIOO .1 Cltl02 Clt40l 1~-PllllllVnoNIUV DBI - 1903I 3 :ISO 504•... . CISO !5_0~~TOFF - I~50 CISOI ../-·~-,1 2 ISOl.,..,;ACSlNOTIS:-1.zvI 1125Cl404,1827smi:s UGO• "' - QG.ii-CUllU:NT. Q400IQ401): ::llSIS101CllS024 - •:.~ JIOnJr. '?• AMU.- 0102.0303GlllNGClllCVIT •I-PIO 0300.TIO! 9 0301-)•rl0102ur.7SCI -u-COlnlCL'10 ClllCU1T0100.0101. FAULTUfPUTCllCUlT•· ·--.QIDI- """21. VOLTAGE ACROSS CIOO rel &ACK MODEL IS SllOWJI IUDW1MODEL NO. '212A &USA '2t~ - 62IOA '211A 1216AYOL1S CDC> 16. 2 11.2 16. 2 u.2 11.2 21.2l. l'OSITM lllAS VOLTAGE "FOR UCH MODEL l$ SHOWJll · IELOW:MQPQ. NO. 6282" &285" &216A 129DA '291A 1216AYOL1S (DC) •lSV •I 7V •UV •2DV '17V •ZDY{ MftP ~CllCUJT0150 tlllt""Ol5J,S2 ~-snNECUUENt/ADJ.COMSEcu:r...i'-•.zv~110:-:aot~1111:·•9.olV•U05. __,@"'YOl.DGE·INPUTcac:UIT,,0100nm:~814YOLts,/. .ADJ. CS09= =COMSEllOLts ) :i:.13ADJ. -'Al-0j·-·.,~~:f802-,_,uu. ..-·1-sJ••3. VOLTAGE ACROSS INPUT FILD:a CAPACITOR FOR PCB MOmLIS SHOWN IELOW:MQQEL NO. 6282" 62 HA Ul6A i290A l29U. &ZHAYOLlS (DC) IS U 24 4!> 45 &SFiqure 4-2. Simplified Schematic•4-2

•••4-S The feedback signals that control the conductionof the series regulator are originated withinthe constant voltage input circuit or the constantcurrent input circuit. The output voltage ofthe power supply is sampled by the constant voltageinput circuit by means of the sensing terminals{:S). The voltage developed across the currentsampling resistor is the input to the constantcurrent input circuit. This voltage drop varies indirect proportion to the output current. Anychanges ·in output voltage/current are detected inthe constant voltage/constant current input circuit,amplified by the gating and error amplifiers,and applied to the series regulator in the correctphase and amplitude to counteract the changes.4-6 The fault input circuit detects the presenceof overvoltage or overcurrent conditic:>ns and generatesthe necessary tum-down signals to theSCR control circuit or the series regulator circuit.In the case of an overvoltage condition, a tumdownsignal is applied to the SCR control circuit.The series regulator receives a turn-down signalvia the gating circuit if an overcurrent conditionis detected.4-7 The reference circuit provides stable referencevoltages which are used by the constantvoltage/current input circuits for comparison pur•poses. The bias supply furnishes voltages whichare used throughout the instrument for biasingpurposes. The meter circuit provides an indicationof output voltage or current in one of tworanges.4-8 SIMPLIFIED SCHEMATIC4-9 A simplified schematic of the power supplyis shown in Figure 4-2. It shows the operatingcontrols; the ON-off pushbutton, the voltage programmingcontrols (R813 and R814) and the currentprogramming controls (R809 and R810). TheMETER switch, i-ncluded in the meter circuit blockon Figure 4-2, allows the meter to read outputvoltage or current in one of two ranges. Figure4-2 also shows the internal sources of bias andreference voltages and their nominal magnitudeswith an input of 115 Vac and no load connected.Diode CR809, connected across the output terminalsof the power supply, is a protective devicewhich prevents internal damage that might occur ifa reverse voltage were applied across the outputterminals. Output capacitor, C809 stabilizes thefeedback loop when the normal strapping patternshown in Figure 4-2 is employed. Note that thiscapacitor can be removed if an increas~ in theprogramming speed is desired. Under these conditions,capacitor C802 serves to insure loopstability. Resistors R811 and R812 limit the outputof the supply if the straps between the outputand sensing terminals are inadvertently opened.4-34-10 DETAILED CIRCUIT ANALYSIS4-11 PREREGUIATOR AND CONTROL CIRCUIT4-12 The prere9ulator minimizes changes in thepower dissipated by the series regulator due tooutput voltage or input line voltage changes.Preregulation is accomplished by means of a phasecontrol circuit utilizing SCR's CRS04 and CRS02 asthe switching elements. The appropriate SCR isfired once during each half-cycle (8.33 milliseconds)of the rectified ac (see Figure 4-3). Noticethat when the SCR is fired at an early point duringthe half-cycle, the de level applied to the seriesregulator is fairly high. When the SCR is firedlater during the cycle, the de level is relativelylow.60Hz AC INPUT ~I 'I I •'-8. JMs-.:1 II IIAll~;c~ --~' I . II • •I '-.\ II I EARLY iI I rIRINCI I POINTSMALL DC __ : ~I~:\ /.LEVCL .Y- - - ~ - - -~U.oERrIRINCPOlllT-Figure 4-3. SCR Phase Control of DC Input Level4-13 The SCR control circuit (See Figure 4-4)samples the input line voltage, the output voltaQe,and the voltage across the series transistor. Itgenerates a firing pulse, at the time required, tofire the SCR so that the voltage across inputcapacitor CSOO will be maintained at the desiredlevel.4-14 The inputs to the control circuit are algebraicallysummed across capacitor C700. All inputscontribute to the time required to charge C700.The input line voltage is rectified by CR704 throughCR707, attenuated by voltage divider R700 and: R701. and applied to the summing point at TP 59via capacitor C700. Capacitor C701 is used forsmoothing purposes.4-15 Transistor Q702, connected in a commonbase configuration, provides a charging currentfor the summing capacitor which varies in accordancewith the input signals applied to its emitter.

•VSERIE.;H:IO -0REG. "'~+v-0-0•10Cll708R7081710~ R7070702CJR9QJ•V -6.ZvCR902;iti=t~CRSQQ ~E4 SCll"S1112C700SUMMINGCAPACJroRR701 C701~I~ :;~pC70Z AJ>J.•15. 4VCR900R900R705CR711 CR710R709R706•6.2VFigure 4-4. SCR Control Circuit, Simplified SchematicResistor R713, connected between the negativeoutput line and the emitter of Q702, furnishes asignal which is proportional to the output voltage.Resistors R708 and R707 sample the voltageacross, and the current through, the series regulator.Capacitor C702 and resistor R709 stabilizethe control circuit feedback loop. ResistorsR7ll and R712 are the source of a constant offsetcurrent which sustains a net negative chargingcurrent to the summing point, ensuring that theSCR's will fire at low output voltages.4-16 The summation of the input signals resultsin the generation of a voltage waveform at TP 59similar to that ~hewn on Figure 4-S. When thelinear ramp portion of the waveform reaches acertain negative threshold voltage, diodes CR711and CR710 become forward biased. The negativevoltage then is coupled to the base of transistorQ701. Transistors Q701 and Q700 form a squaringcircuit resembling a Schmitt trigger configuration.Q701 is conducting, prior to firing time, due to·the positive bias connected to its base throughR705. Transistor Q700 is cut off at this time becauseits base is connected directly to the collectorof conducting transistor Q701. When the negativethreshold voltage is reached, transistorQ701 is turned off which turns Q700 on. Theconduction of Q700 allows capacitor C703 to dischargerapidly through pulse transformer T700resulting in the SCR firing pulse shown on theTP59 THR£5HOU>FIRING. --rSUMMING POINT I I lNOTES;TP47OUTPUT 0700"'-8. lMS II I I- -~-.....:~NOTE 3)nnTP46l'llUNG PULSE(EXPANDED)TPSZRESETl:Vl 11 '-1:-; : II Il!iV_J_I l c··-J, ' • J_' II Il. ALL WAVEFORMS REFERENCED TOINBOARD SIDE or CURRENT SAM­PLING RESISTOR R800 EXCEPTl'IRJNG PULSE WHICH IS REFEll·ENCED TO T. P. 45.2. FOR CLAllJTY WAVEFORMS ARE NOTDRAWN TO SCALE.3. AMPLITUDE OF THIS WAVEFORM ISAPPROXIMATE ANO VAIUES SUGHTLYl'ROM MODEL 'TO MODEL IN AC·COROANCE WITH THE POSmvECOLLECTOR BIAS OBTAINED FROMcaoo.----r1911--1.Figure 4-5. SCR Control Circuit Waveforms••4-4

~TING.__-+....,. _••diagram. The firing pulse ls. relatively narT"ow becauseQ700 saturates rapidly causing the magneticfield surrounding T700 to collapse. Diode CRSOOdamps out the negative overshoot.4-17 Reset of the control circuit occurs onceevery 8.33 milliseconds when the rectified acvoltage at test point 52 recedes to a level atwhich diode CR709 becomes forward biased.Summing capacitor C700 is then allowed to dischargethrough CR709. Diodes CR711 and CR710become reverse biased at reset and transistorQ701 reverts to its "on" state. Consequently,Q700 is turned off and capacitor C703 charges upthrough R703 at a comparatively slow rate until thecollector voltage of Q700 reaches approximately+17 volts. The above action causes the smallnegative spike that appears across the winding ofpulse transfonner T700 at reset time.4-18 Capacitor C900, diode CR900, and ~storR900 fonn a long time constant network whichachieves a slow tum-on characteristic. When theunit is firSt turned on, C900 provides a positivevoltage to the cathode of CR71 l to ensure that ltls initially reverse biased. After C900 becomesfully charged, the control circuit ls permitted tofire the SCR's. Diode CR902 provides a dischargepath for C900 when the unit ls turned off.4-19 SERIES REGUIATOR4-20 The series regulator (transistor Q400 orQ400 and Q401, see schematic at rear Of manual)·serves as the series, or "pass", element whichprovides precise and rapid control of the output.The conduction of the series translstor(s) ls controlledby the feedback signals obtained fromdriver Q303. Diode CR400, connecteii across theregulator circuit, protects the series element(s)from reverse voltages that could develop ac.;rossthem during parallel operation if one supply isturned on before the other.4-21 CONSTANT VOLTAGE INPUT CIRCUIT (SeeFigurP 4-6)4-22 The circuit consists of the programming resistors(RB13 and R814) and a differential amplifierstage (QlOO and associated components). TransistorQlOO consists of two silicon transistorshoused in a single package. The transistors havematched characteristics minimizing differentialvoltages due to mismatched stages. Moreover,drift due to thermal differentials ls minimized,since both transistors operate at essentially thesame temperature.4-23 The constant voltage input ctrcuit continuouslycompares a fixed reference voltage w 1th aportl.On of the output voltage and, if a differenceexists, produces an error voltage whose amplitudeand phase is proportional to the difference. Theerror output is fed back to the series regulator,through the gating and error amplifiers. The errorvoltage changes the conduction of the seriesregulator which, in tum, alters the output voltageRIOOA•6.ZV+9.('i10CIRcurTll03ll07CIUOZ__.,._ ___ ,.+U,4¥llOSPU1.LOUTU:S.ISTClluo•RlO' RlOI-6.%V R105•6.ZVCIOl•Figure 4-6. Constant Voltage Input Circuit, Simplified Schematic4-S

so that the difference between the two input voltagesapplied to the differential amplifier is reducedto zero. This action maintains the outputvoltage constant.4-24 Stage QlOOA of the differential amplifier isconnected to a common (+S) potential through impedanceequalizing resistor Rl06. Resistors Rl02and Rl 08 are used to zero bias the input stage.offsetting minor base to emitter voltage differencesin QlOO. The base of QlOOB is connectedto a summing point (A4) at the junction of the programmingresistors and the current pullout resistorRSOS. Instantaneous changes in the output(due to load variations) or changes due to themanipulation of RBl 3, result in an increase ordecrease in the summing point potential. 01008is then made to conduct more or less, in accordancewith summing point voltage change. Thechange in QlOOB's conduction also varies theconduction of Ql OOA due to the coupling effects ofthe common emitter resistor, RIOS. The "errornvoltage is taken from the collector of QlOOA andultimately varies the conduction of the seriesregulator.4-25 Resistor Rl04, in series with the base ofQlOOB. limits the current through the programmingresistors during rapid voltage tum-down. DiodesCRlOO and CRlOl form a limiting network whichprevents excessive voltage excursions from overdriVing stage QlOOB. Capacitor C801, shunting-i.2Vthe programming resistors, increase the highfrequency gain of the input amplifier. ResistorR806, shunting the pullout resistor, serve1s as atrimming adjustment for the programming current ••Diode CR102 establishes the proper collector biafor QlOOA while R103 and ClOO proVide low frequencyequalization for the feedback loop.4-26 CONSTANT CURRENT INPUT CIRCUI'I' (SeeFigure 4-7)4-27 This circuit is similar in appearance andoperation to the constant voltage input circ:uit. Itconsists of the coarse and fine current pr01;rammingresistors (R809 and RS! O), and a difforentialamplifier stage (Q200 and associated components).Like transistor QlOO in the voltage input ciircuit,Q200 consists of two transistors, having matchedcharacteristics, that are housed in a singl1~ package.4-28 The constant current input circuit continuouslycompares a fixed reference voltage with thevoltage drop across the current sampling re:sistor.If a difference exists, the differential amplifierproduces an "error" voltage which is propo1rtionalto this difference. The remaining components inthe feedback loop (amplifiers and series re·;ulator)function to maintain the drop across the cu:rrentsampling resistor, and consequently the outputcurrent, at a constant value.-r..zv•?OGATING--~-..... ---+--...ClllCUIT1801P11U.OVTRESISTORltl08CIOS-L2VR827RIOOAFigure 4-7. Constant Current Input Circuit, Simplified Schematic•4-6

•••4-29 Stage Q200A is connected to +S through impedanceequalizing resistor R203. Instantaneouschanges in output current on the positive line arefelt at the current summing point (terminal A7) and,hence, the base of Q200B. Stage Q200B varies itsconduction in accordance with the polarity of thechange at the summing point. The error voltage istaken from the collector Q200B and ultimatelyvaries the conduction of the series regulator.4-30 Resistor R304, in conjunction with C300,helps stabilize the feedback loop. Resistor R808,shunting the pullout resistor, serves as a trimmingadjustment for the programming current flowingthrough R809 and R810.4-31 GATING CIRCUIT4-32 The gating circuit (see schematic) consistsof gating amplifiers Q301 and Q300 and associatedOR-gate diodes, CRJOO and CR301. The gatingcircuit provides sharp crossover between constantvoltage and constant current operation. Duringsteady state conditions, one transistor is saturatedwhile the other is conducting in its linearregion. The cathodes of the OR-gate diodes arealways at a more positive potential than the satuationpotential of 0300 or Q301. Thus, the diodeassociated with the saturated transistor is reversebiased while the diode associated with the othertransistor is forward biased. In the constant voltagemode Q301 is operating in its linear regionand Q300 is saturated due to the positive collectorvoltage of Q200B. OR-gate diode CR301 is thereforereverse biased while OR-gate diode CR300 isforward biased, coupling the constant voltagefeedback si9nal to the error amplifier. Oppositeconditions prevail during constant current operation.4-33 Capacitor C302 is a commutating capacitorwhich improves the transient response of the unit.Resistor R300 is the biasing resistor for the ORgatediodes.4-34 ERROR AMPLIFIERS4-35 The error amplifiers Q302 and QJOJ, amplifythe feedback. si9nal from the constant voltageor constant current input circuit to a level sufficientto drive the series regulator transistor.Transistor Q303 serves as the driver and Q302 thepredriver. for the series regulator. The RC network,composed of C301 and R307, is an equalizingnetwork which provides for high frequency rolloffin the loop gain response in order to stabilizethe feedback loop .4-36 Capacitor C900, diode CR901, and resistorR902 form a long time constant network whichachieves a slow tum-on characteristic. When theunit is first turned on, C900 provides a positivevoltage to the base of Q302 keeping the seriesregulator from conducting initially. As C900charges up, the restrictive bias becomes lesspositive enabling the regulator to conduct. DiodeCR902 provides a low resistance discharge pathfor C900 when the unit is turned off.4-37 FAULT INPUT CIRCUIT4-38 The fault input circuit (see schematic atrear) protects the power supply against overvoltageand overcurrent conditions. Transistor 0800,and associated components, comprise the overvoltagedetector. With normal output voltagesQSOO is cut off due to the +15.4V reference voltageconnected to the top of voltage divider R823 andR821. If the output voltage exceeds a certainlimit (about 20% above the maximum rated outputvoltage) transistor QSOO is driven into conduction.Current is then conducted away from the summingpoint and in opposition to the charge path of C700in the SCR control circuit. As a result, the SCR' sare fired at a later time, reducing the series regulatorinput voltage to a safe value.4-39 A full wave rectified voltage, obtained fromthe SCR control circuit, excercises a stabilizinginfluence on transistor QBOO. This signal tendsto synchronize the conduction of QBOO at a 120 Hzrate preventing random firing of the SCR' s.4-40 Transistors Q801 and Q802 provide overcurrentand short circuit protection for the unit.Overcurrent protection is accomplished by Q802which is activated only 1f the constant currentinput circuit should fall. Q802 monitors the voltagedrop across the current sampling resistor andconducts if this drop exceeds a certain level.The output of Q802 is fed to gating amplifier QJOlvia R815 and ultimately reduces the conduction ofthe series regulator.4-41 Short circuit protection is provided by transistorsQ801 and Q802. Transistor Q801, normallybiased below cutoff, monitors the voltage dropacross the series regulator. Under short circuitconditions, the ·increased voltage across the regulatordrives Q801 into saturation. The positivegoing emitter voltage of Q801 also drives Q802into conduction. The output of Q802 limits thecurrent flow through the series regulator to a prescribedleve 1.4-7

4-42 REFERENCE CIRCUIT (See Schematic at Rear)4-43 The reference circuit is a feedback powersupply similar to the main supply. It providesstable reference voltages which are used throughoutthe unit. The reference voltages are allderived from smoothed de obtained from the fullwave rectifier (CR600 and CR601) and filter capacitorC600. The +9.4 and -6.2 voltages are developedacross temperature compensated Zener diodesVR600 and VR60l. Resistor R611 limits the currentthrough the Zener diodes to establish an optimumbias level.4-44 The regulating circuit consists of seriesregulating transistor Q600, error ammplifier Q601,and differential amplifier Q602 and Q603. Thevoltage across the Zener reference diode VR600and the voltage at the junction of divider R605 andR606 are compared, and any differences are de-tected by Q602 and Q603. The error voltage isamplified and inverted by Q601 and appli.ed toseries requlator Q600 in the correct phase andamplitude to maintain the +15.4 volt output con.stant.4-45 Zener diode VR601 provides an add:ltionalbias voltage of -6.2 volts. Resistor R60l, connectedacross Q600, minimiZes power di:;sipationin the series element. Output capacitor C602stabilizes the reference regulator loop.4-46 METER CIRCUIT4-47 The meter circuit (see Figure 4-8) providescontinuous indications of output voltage •lr currenton a single multiple range meter. The metercan be used either as a voltmeter or an ammeterdepending upon the position of METER switch S2on the front panel of the supply. This SVl'itch1800CtJRllENTSAM PUNGRl:SJSTOR CSIIR869R85318SZ•RB62RB61RB&O11851R872R8'1R857QH2RISOHOtt:S2 FOSmoNS FOR I>IFFERENT MOI>EUARE SHOW?-! BELOW:MODELS2 TERl\.!TN& NOS.I 2 3 4628ZA l.2V 12V HA l.ZA628;.\ 2. 4V 24V 6A .6A6286A 2.4V Z4V IZA l.ZA629~A ;v ;ov 4A .4A6291.\ sv. sov 6A .6A6Z96A 7V 70V 4A .u.Figure 4-8. Meter Circuit. Simplified Schematic•4-8

••also selects one of two meter ranges on eachscale. The metering circuit consists basically ofa selection circuit (switch S2 and associatedvoltage dividers), a stable differential amplifierstaqe (QBSlA and Q8518), two meter amplifiers(Q852 and Q853), and the meter movement.4-48 The selection circuit determines whichvoltage divider is connected to the differentia 1amplifier inpu~. When S2 ls in one of the voltagepositions, the voltage across divider RBSO, RBSl.and R852 (connected across the output of the supply)is the input to the differential amplifier.When 52 is in one of the current positions, thevoltage across divider R853, R854, and RSSS (connectedacross the sampling resistor) is the inputto the differential amplifier. With S2 in the highervoltage range (position 2) the voltage drop acrossR852 is applied to stage Q851A while stageQ851B is grounded tothe +s terminal. For low outputvoltages, S2 can be set to position (1) resultingin the application of a larger percentage of theoutput voltage (drop across RSS l and RBS 2) tostage Q851A. With 52 in the higher current position(3) the voltaqe drop across R853 is appliedto stage Q851B while stage Q851A is grounded tothe +S terminal. In the low current range, thevoltage drop across R853 and R854 is applied toQ851B.4-49 Differential amplifier stage Q851 is astable device having a fixed gain of ten. Tominimize temperature effects, the two stages arehoused in a single package that is similar tothose used in the constant voltage and current inputcircuits. The outputs of the differential amplifierdrive meter amplifiers Q852 and Q853which, in turn, deflect the meter. TransistorQ850 provides a constant bias current to the emittersof Q852 and Q853. Potentiometer R870 permitselectrical zeroing of the meter.4-50 The meter circuit contains an inherent currentlimiting feature which ~rotects the metermovement against overloads. For example, lfME1'~R switch 52 is placed in the low currentrange when the power supply is actually deliveringa higher ampere output, the differential amplifiersare quickly driven into saturation, limitingthe current through the meter to a safe value .•4-9

•SECTION VMAINTENANCE••5-1 INTRODUCTION5-2 Upon receipt of the power supply, the performancecheck (Paragraph 5-10) should be made.This check is suitable for incoming inspection. Ifa fault is detected in the power supply while makingthe performance check or during normal operation.proceed to the troubleshooting procedures (ParagraphS-41). After troubleshooting and repair (ParagraphS-46), perform any necessary adjustmentsand calibrations (Paragraph 5-48). Before returningthe power supply to normal operation, repeat theperformance check to ensure that the fault has beenproperly corrected and that no other faults exist.Before doing any maintenance checks, tum on powersupply, allow a half-hourwarm-up, and read the'general information regarding measurement techniques(Paragraph 5-3).5-3 GENERAL MEASUREMENT TECHNIQUES5-4 The measuring device must-be connectedacross the sensing leads of the supply or as closeto the output terminals as possible when measuringthe output impedance, transient response, regulation.or ripple of the power supply in order toachieve valid measurements. A measurement madeacross the load includes the impedance of the leadsto the load and such lead lengths can easily havean impedance severa 1 orders of magnitude greaterthan the supply impedance. thus invalidating themeasurement.S-5 The monitoring device should be connectedto the +S and -s terminals (see Fic;ure 3-2) or asshown in Figure S-1. The performance characteristicsshould never be measured on the front terminalsif the load is connected across the rear terminals.Note that when measurements are made at the frontterminals. the monitoring leads are connected at A,not B, as shown in Figure S-1. Failure to connectthe measuring device atA willresuitin a measurementthat includes the rest.stance of the leads betweenthe output terminals and the point of connection.S-6 For output current measurements, the currentsampling resistor should be a four-terminal rests-LOAD LEADFigure 5-1. Front Panel Terminal Connectionstor. The four terminals are connected as shown inFigure 5-2. In addition, the resistor should be ofthe low noise, low temperature coefficient Oessthan 30ppmfOC) type and should be used at nomore than 5% of its rated power so that its temperaturerise will be minimized.CURRENT SAMPLINGTERMINALSTO UNGROUNDEDTO GROUNDEDTERMINAL OF +-W.--~W.."'0---1• TERMINAL OFPOWER SUPPLYPOWER SUPPLYFigure 5-2. Output Current Measurement Technique5-7 When using an oscilloscope, ground one terminalof the power supply and then ground the caseof the oscilloscope to this same point. Make certainthat the case is not also grounded by someother means (Power line). Connect both oscillo-. scope input leads to the power supply ground terminaland check that the oscilloscope is not exhibitinga ripple or transient due to ground loops, pickup,or other means.s-e TEST EQUIPMENT REQUIREDS-9 Table 5-1 lists the test equipment required toperform the various procedures described in thisSection .5-1

TypeTable 5-1. Test Equipment RequiredRequiredUseRecommended:Characteristics Model•Differential Sensitivity: 1 mv full scale Measure DC voltages; ~ 3420 (See Note)Voltmeter (min.J. Input impedance: calibration procedures10 megohms (min.).-Variable Range: 90-130 volts. Vary AC input----------------Voltage Equipped with voltmeterTransfonner accurate within 1 volt.AC Voltmeter Accuracy: 2%. Sensitivity: Measure AC voltages and ~ 403 B1 mv full scale deflection ripple(min.).Oscilloscope Sensitivity: 100 ~v/cm. Display transient response ~ 140 A plusDifferential input. waveforms 1400A plug in.Oscillator Range: SHz to l MHz. Impedance checks e 200 CDAccuracy: 2%.DC Voltmeter Accuracy: 1%. Input Measure DC voltages ~ 412Aresistance: 20, 000 ohms/volt(mtn.l.•Repetitive Rate: 60 - 400 Hz, 21'5eC Measure transient response See Figure 5-7Load Switch rise and fall time.Resistive Value: See Paragraph 5-14. Power supply load resistors-------------··--Loads and Figure 5-4. ::1:5% 250 watts.Current Value: See Figure 5-4. Measure current: calibrate -------------·---Sampling 111. 200 watts, 20ppm. meterResistor 4-Terminal.Resistor l'Kt.. ::1:1%. 2 watt non-inductive Measure impedance----------------Resistor 100 ohms. i:S%. 10 watt Measure impedance -------------··--Resistor Value: See Paragraph 5-45. Calibrate programming current -------------··--:tO. 1 %. 20 watt.•5-2

•TypeResistorCapacitorDecadeResistanceBoxRequired RecommendedCharacteristics Use ModelValue: See Paragraph 5-47. Calibrate programming current----------------:t:O. 1 %. l/2 watt.500µ.f, 50 wvdc Measure impedance.----------------Range: 0-SOOK. Measure programming----------------Accuracy: 0. 1% plus l ohm coefficients.Make-before-break contacts.•NOTEA satisfactory substitute for a differential voltmeteris to arrange a reference voltage source and nulldetector as shown in Figure S-3. The referencevoltage source is adjusted so that the voltage differencebetween the supply being measured and thereference voltage will have the required resolutionfor the measurement being made. The voltage differencewill be a function of the null detector that isused, Examples of satisfactory null detectors are:S 419 A null detector, a DC coupled oscilloscopeutilizing differential input, or a SO mv meter movementwith a 100 division scale. For the latter, a2 mv change in voltage will result in a meter deflectionof four divisions.CAUTIONCare must be exercised when using an electronicnull detector in which one input terminal is groundedto avoid ground loops and circulating currents.POWtR SUPPLYUNDER TESTREfUENCtVOLTAGESOURCES-10 PERFORMANCE TEST•LOADNllU. "DETECTORFigure 5-3. Differential Voltmeter Substitute,Test Setup05-11 The following test can be used as an incominginspection check and appropriate portionsof the test can be repeated either to check theoperation of the instrument after repairs or forperiodic maintenance tests. The tests are perfonned using a 115-VAC 60 cps., single phase inputpower source. If the correct result is not obtainedfor a particular check, do not adjust anycontrols; proceed to troubleshooting (Paragraph5-28) •S-3

5-12 CONSTANT VOLTAGE TESTS5-13 Rated Output and Meter Accuracy.5-14 Voltage. Proceed as follows:a. Connect load resistor across rear outputterminals of supply. Resistor value to be as follows:Model 6282A 628SA 6286A 6290A 6291A 6296ARes. 1"'. 4A ~ llA ~ 20~b. Connect differential voltmeter across +Sand -s terminals of supply observing correct polarity.c. Set METER switch to highest voltage rangeand turn on supply.d. Adjust VOLTAGE controls until front panelmeter indicates exactly the maximum rated outputvoltage.e. Differential voltmeter should indicatemaximum rated output voltage within :t2%.POWER SUPPLYUNDER ?£STMODEL NO. IR6281A 0. 206282A 0. JO6284A 0. l36285A 0. 206286A 0. 106289A 0. 666290A 0. 336291A 0. 206294A I. 06296A 0. 336299A I. 33OtrrtRENTIALVOLTMETERRI. 300. 9063. 80I. 90zi137. 805919. 66131•5-15 Current. Proceed as follows:a. Connect test setup shown in Figure 5-4,leaving switch S l open.b. Tum CURRENT controls fully clockwise.c. Set METER switch to highest current rangeand turn on supply.d. Adjust VOLTAGE controls until front panelm~ter indicates exactly the maximum rated outputcurrent.O. 02 Vdc.e. Differential voltmeter should read 1. 0 zFigure S-5. Load Regulation, Constant Voltc:1ged. Adjust VOLTAGE controls until front panelmeter indicates exactly the maximum rated outputvoltage.e. Read and record voltage indicated ondifferential voltmeter.f. Disconnect load resistors·.g. Reading on differential voltmeter should •not vary from reading recorded in step e by morethan the following (variations expressed in mV"dc):Model 6282A 6285A 6286A 6290A 6291A 64!96AVariation :t2 :3 :1:3 :1:5 :5 :t7POWER Sll~Pl.YUNDER TEST0. 90l. 81. 9ll?. 819 66NOTEIf measurements are made at the frontterminals, readings will be O.SmV peramp greater due to front terminal resistance.CURRCNTSAM PUNGRESISTOROIFrtllENTlALVOL?MCTERFigure· 5-4. Output Current Test SetupS-16 Load Regulation. To check constant voltageload regulation, proceed as follows:a. Connect test setup as shown in Figure 5-5.b. Turn CURRENT controls fully clockwise.c. Set METER switch to highest currentrange and turn on supply.5-17 Line Regulation. l'o check the line regullation,proceed as follows:a. Connect variable auto transformer betweeninput power source and power supply power input.VAC input.b. Turn CURRENT controls fully clockwise.c. Connect test setup shown in Figure s-s.d. Adjust variable auto transformer for 105e. Set METER switch to highest voltagerange and turn on supply.f. Adjust VOLTAGE controls until front panelmeter indicates exactly the maximum rated outputvoltage.g. Read and record voltage indicated on. differentialvoltmeter. •VAC input.h. Adjust variable auto transforn:ier for l.25S-4

•i. Reading on differential voltmeter shouldnot vary from reading recorded in step g by morethan the following (variations expressed in mVdc):Model 6282A 628SA 6286A 6290A 6291A 6296.AVariation :2 :±3 :1:3 :5 ±5 :75-18 Ripple and Noise. To check the ripple andnoise, proceed as follows:a. Retain test setup used for previous lineregulation test except connect AC voltmeter acrossoutput terminals as shown in Figure 5-6.b. Adjust variable auto transformer for 125VAC input.c. Set METER switch to highest current range.d. Turn CURRENT controls fully clockwiseand adjust VOLTAGE controls until front panel meterindicates exactly the maximum rated output voltage.e. AC voltmeter should read less thanO. 50mVrms.POWER SUPPLYUNDER 'ltSTPOWtR SUPPLYUNDER TEST~ODEL NO.+0 0-+--------------------1-.0CONTACT PROTECTIONNtl'WORICl..ld I" SW200V (NOTE 31 Rxf----·Vlll.--..l\/V\.--1RESIS A~·Rx•~u~••a.,6282A 0.10 0.90628SA 0.20 3. 806286A 0.10 1.906290A 0. 33 13. 06291A 0.20 7. 806296" 0. 33 I 1'. 66.,IRyOSCILLOSCOPE,, 140AG0NOTES:I. THIS DRAWING SHOWSA SVCGESTED METHODor BUILDING A L~DSWITCH. HOWMR.OTHER METHODS COULDIE USED: SUCH AS ATRANSISTOR SWITCHINGNETWORK. MAXIMUMLOAD RAnNGS or LOADSWITCH ARE; S AMPS.SOOV. ZSOW INOT 2S0'1Wl2. USE MERCURY REIAY:CURE TYPE HGP I 002 ORW. E. TYPE 2768.l. USE Wtat WOUND RC.~ISTOR.Figure S-7. Transient Response, Test Setup•LOAO RtSISTORSAC VOLTMma,, 403 •f. Adjust 2SK potentiometer until a stabledis play is Qbtained on oscilloscope. Waveformshould be within the tolerances shown in Figure S-8(output should return to within 15 mV of originalvalue in less than 50 microseconds).f---so .... ~ J __I I ISMVov-r-----__,,,c.... ____ ,i;;:::;::;._-r--Figure S-6. Ripple and Noise. Constant Voltage•5-19 Transient Recovery Time. To check thetransient recovery time proceed as follows:a. Connect test setup shown in Figure 5-7.b. Turn CURRENT controls fully clockwise.c. Set METER switch to highest currentrange and turn on supply •. d. Adjust VOLTAGE ~ontrols until front panelmeter indicates exactly the maximum rated outputcurrent or S amperes, whichever is smaller.e. Close line switch on repetitive loadswitch setup.I1-so..stc-tUNLOADING TRANSIENT~DING TRANSIENTFigure 5-8. Transient Response Waveforms_:s-20 Output Impedance. To check the output impedance,proceed as follows:a. Connect test setup shown in Figure S-9 •5-5

VOLTMEltR VOLTMmltIp 40) B Ir 40) IINDICATES E 0 INDICATES E;n) (> ~ 0POWER SUPPLY OSCIUATORUNDER TtsT~/ -/ 0 h'J\11."v100 OHMft 200 CD.... ~+c.__H U>I!IC SQO MrDI... \I-11+Figure S-9. Output Impedance, Test Setupb. Set METER switch to highest voltage rangeturn CURRENT controls fully clockwise, and turn onsupply.c. Adjust VOLTAGE controls until front panelmeter reads 10 volts.d. Set AMPLITUDE control on Oscillator to10 volts (Ein>. and FREQUENCY control to lOOHz.e. Record voltage across output terminals ofthe power supply (Eo) as indicated on AC voltmeter.f. Calculate the output impedance by thefollowing formula:EoRZout = Ein - EoEo = nns voltage across power supply outputR = 1000terminals.Ein= 10 voltsg. The output impedance (Zout> should beless than 0.001 ohm.h. Using formula of step f, calculate outputimpedance at frequencies of lKHz, lOOKHz, andlMHz. Values should be less than 0.01 ohm, 0.2ohm, and 2 ohms, respectively.S-21 CONSTANT CURRENT TESTSS-22 Load Regulation. To check the constant currentload regulation, proceed as follows:a. Connect test setup shown in Figure 5-4.b. Turn VOLTAGE controls fully clockwise.c. Set METER switch to highest currentrange and turn on supply.d. Adjust CURRENT controls until front panelmeter reads exacUy the maximum rated output current.e. Read and record voltage indicated on differentialvoltmeter.switch Sl.f. Short out load resistor (Ry) by closj.ngg. Reading on differential voltmeter shouldnot vary from reading recorded in step e by morethan the following {variations expressed in mVdc): •Model 6282A 628SA 6286A 6290A 6291A li296AVariation :1.:0. 60 :1:2. 20 :1.:0. 60 :t0.830 :t0.70 :1::0.8305-23 Line Regulation. To check the line regulation,proceed as follows:a. Utilize test setup shown in Fiqure 5-4leaving switch Sl open throughout test.b. Connect variable auto transformer b1!tweeninput power source and power supply power input. .. ·: ·c. Adjust auto transformer for lOSVAC input.d. Turn VOLTAGE controls fully clockwise.e. Set METER switch to highest current rangeand tum on supply.f. Adjust CURRENT controls unW front panelmeter reads exactly the maximum rated output current.g. Read and record voltage indicated (Jn differentialvoltmeter.VAC input.h. Adjust variable auto transformer fo1~ 125i. Reading on differential voltmeter sltlouldnot vary from reading recorded in step 9 by morethan the following {variations expressed in mVdc):Model 6282A 628SA 6286A 6290A 6291A 6296AVariation :1:0.60 :1:2.20 :t0.60 :t0.830 :tQ.70 :i:0.8305-24 Ripple and Noise. To chec~ the ripple' and •noise, proceed as follows:a. Use test setup shown in Figure 5-

••5-27 TROUBLE ANALYSIS5-28 General. Before attempting to trouble shootthis instrument, ensure that the fault is with theinstrument and not with an associated circuit.The performance test (Paragraph 5-10) enables thisto be determined without having to remove the instrumentfrom the cabinet.5-29 Once it is determined that the power supplyis at fault, check for obvious troubles such asopen fuse, a defective power cable, or an inputpower failure. Next, remove the top and bottomcovers (each held by four retaining screws) andinspect for open connections, charred components,etc. If the trouble source cannot be detected byvisual inspection, follow the detailed procedureoutlined in succeeding paragraphs. Once the defectivecomponent has been located (by means ofvisual inspection or trouble analysis) correct itand re-conduct the performance test. If a componentis replaced, refer to the repair and replacementarxi adjustment and calibration paragraphs inthis section.S-30 A good understanding of the principles ofoperation is a helpful aid in troubleshooting, andit is recommended that the reader review Section IVof the manual before attempting to troubleshoot theunit in detail. Once the principles of operation areunderstood, logical application of this knowledgeused in conjunction with the normal voltage readingsand wavefcrms shown on the schematic and the additionalprocedures given in the following paragraphsshould suffice to isolate a fault to a compo­.-ient or small group of components. The componentlocation diagram at the rear of the manual can beconsulted to determine the location of componentsand test points. The normal voltages shown on theschematic are positioned adjacent to the applicabletest points (identified by encircled numbers on theschematic and component location diagram). Additionaltest procedures that will aid in isolatingtroubles are as follows:·a. Reference circuit check (Paragraph 5-31).This circuit provides critical operating voltages fathe supply and faults in the circuit could affect theoverall operation in many ways. This circuit shouldbe checked first, before proceeding to other areasof the unit.b. Series regulator and preregulator feedbackloop checks (Paragraph 5-32).c. Procedures for dealing with commontroubles (Paragraph S-33}.5-31 Reference Circuit.a. Make an ohmmeter check to be certainthat neither the positive nor negative output terminalis grounded.b. Turn front-panel VOLTAGE and CURRENTcontrols fully clockwise (maximum).c. Turn on power supply (no load connected).d. Proceed as instructed in Table 5-2.5-32 Series Regulator and Prerequlator FeedbackCircuits. GenerallY> malfunction of these two feedbackcircuits is indicated by high or lQw (or no)output voltage. If one of these situations occur,disconnect the load and proceed as instructed inTable 5-3 or 5-4. Preregulator waveforms are includedon the schematic at the rear of the manual.5-33 Common Troubles. Table 5-6 lists thesymptoms, checks, and probable causes for commontroubles.S-34 REPAIR AND REPLACEMENT5-35 Before servicing a printed wiring board, referto Figure 5-10. Section VI of this manual containsa list of replaceable parts. Before replacing asemiconductor device, refer to Table 5-7 whichlists the special characteristics of selected semiconductors.If the device to be replaced is notlisted in Table 5-7, the standard manufacturerspart number listed in Section VI is applicable.After replacing a semiconductor device, refer toTable 5-8 for checks and adjustments that may benecessary.Table 5-2. Reference Circuit TroubleshootingStepMeter Meter NormalCommon Positive IndicationIf Indication Abnormal. Take This Action1 +S 29 9. 4 %0. 4Vdc Check 15. 4 volt bias or VR6002 28 +S 6. 2 +O. 3Vdc Check diode VR601•3 +s 30 15. 4 +o. 5Vdc Check R605, Q600 through Q603, C600, CR600and CR601 •S-7

Table 5-3. Hi9h Output Volta9e TroubleshootingStep Measure Response Probable Cause1 Voltage between TP26 and TP90 a. OV or negative a. 0400(0401) shortedCR400 shorted•b. More positive th-an b. 0303 open or R309 shortedov Proceed to Step 22 Voltage between +s and A4 a. OV to +O. 8V a. Open strap A3-A4R813 or R814 openR805 or R806 shortedb. More negative than b. Proceed to Step 33 Voltage between +S and 11 a. More positive than a. 01008 shortedov+l. 5V OlOOA openb. +o. 9V to +1. 5V b. Proceed to Step 44 Voltage between +s and 21 a. More negative than a. 0302 openov 0301 openR30S. R300 shortedTable 5-4. Low Output Voltage TroubleshootingStep Measure Response I Probable Cause1 Voltage between TP26 and TP90 a. More positive than a. Proceed to Step 2ovb. OV or negative b. Proceed to Step 3•2 Voltage between TP90 and TP27 a. Less positive than a. Chee le fuse Fl. If blow111+4V check CRS02 or CRS04 forshort. If not blown, proceedto Table s-s.b. More positive than b. 0400 (0401) open+sv Proceed to Step 33 Disable Q200 by disconnect- a. Normal output a. Constant Current circuiting CR200 voltage faulty; check 02008,R810. R809, for short.b. Low output voltage b. If supply is furnishing currentwithout load, checkCR809, C802, or C803 fc>rshort. If it is not, proceedto Step 34 Voltage between +S and A4 a. More negative a. Open strap A4-ASthan OV R813, R814, C801Proceed to Step 55-8•

•sTable 5-4. Low Output Voltage Troubleshooting (Continued)Step Measure Response Probable CauseVoltage between +s and 11 a. Less positive than a. QlOOB open+0.9V QlOOA shortedQ802 or Q80l shonedb, +O. 9V to +l. SV b. Proceed to Step 66 Voltage between +s and 21 a. OV or positive a. Q303 shorted0302 shortedR3 l O shortedTable S-5. Preregulator/Control Circuit TroubleshootingStep Measure Response Probable Causel Waveform between 4 and 3 of a. Normal firing pulse a. CRS02-CRS04 defectiveT700 R50l-RS02 openCRSOl, CR503, T800defectiveb. No or abnormal fir- b. T700 opening pulse CRSOO shortedProceed to Step 2•2 Waveform between 90 and 47 a. Zero or small posi- a. Q7 00 shortedtive voltage C703 shortedQ701 openR703, primary T700 openProceed to Step 3b. +16 to +20 Volt level b. Q700 openR703 shortedQ70l shonedProceed to Step 3c. Waveform distorted c. Proceed to Step 33 Waveform between 90 and 59 a. Amplitude incorrect a. Q702 defectiveR707,R708, R713 incorrectvalue or openC700, CR710, C711 defectiveb. Period incorrect b. CR709 defectiveProceed to Step 44 Waveform between 90 and 52 a. Amplitude incorrect a. CR708, CR709, R702 defectiveb. Period incorrect b. CR700 through CR703defective•s Waveform between 90 and 54 a. Amplitude incorrect a. R700, R701, C701 defectiveb. Period incorrect b • CR704 throuqh CR707 defective5-9

Table 5-6. Common TroublesSymptom Checks and Probable Causesa. Check operating setup for ground loops,High ripple under loaded conditions.b. If output floating, connect 1 µ.f capacitor between output and ground•c. Ensure that supply is not crossing over to constant current moded. Check for low voltage across CSOO or Q400.e. Check for excessive ripple on reference voltages. Peak-to-peakripple should be less than 2mV for +9. 4V and -6. 2V and less than4mV for +15. 4V.Poor line regulation a. Check reference circuit (Paragraph 5-31).a. Measurement technique. (Paragraph 5-16.)Poor load regulation b. Check reference circuit (Paragraph 5-31).(Constant Voltage) c. Ensure that supply is not going into current limit. Check consta.ntcurrent input circuit.a. Check reference circuit (Paragraph 5-31).Poor load regulation b. C802, C803, and CR809 leaky,(Constant Current) c. Ensure that supply is not crossing over to constant voltage operation.Check constant voltage input circuit.Oscillates (ConstantVoltage I ConstantCurrent)Poor Stability(Constant Voltage)Poor Stability(Constant Current)a.Check C301 for open, adjustment of R307 (Paragraph 5-50).b. Check Rl03, ClOO or R304, C300.a. Check reference voltages (Paragraph 5-31).b. Noisy programming resistors R813, R814.c. CR100, CRlOl leaky.d. Check Rl04, R805, R806, CS 0 l for noise or drift... e • Stage QlOO defective.•a. Check reference voltages (Paragraph 5-31).b. Noisy programming resistors R809, R81 o.c. CR809, C803, C802 leaky.d. Check R807, R808, R200, R800, for noise or drift.e. Stage Q200 defective.Table 5-7. Selected Semiconductor CharacteristicsReferenceCharacteristics ~ Stock No.SuggestedDesignator ReplacementQlOO, Q200Matched differential amplifier.NPN Si Planar. 70 (min.)hFE IC= 1 mA. VcE = 5V.Ico 0.01 µ.a @Vcbo = SV.1854-02292N2917 G. E.Q303. Q400 NPN power. hFE = 35 (min);(Q401) @ le = 4A. VcE = 4V.1854-0225 2N3055 R. C. A.Q851Matched differential amplifier.NPN Si.5-101854-0221 2N4045 Union Carbide•

Table 5-7. Selected Semiconductor Characteristics (Continued)•CR100-CR102,CR200, CR300, CR301. Si diode, 200 mA. 200 prvCRSOO, CR700, CR7011901-0033 1N48SB SylvaniaCR402. CR602,CR803-CR806Si Stabistor. 200 mA. 15 prv 1901-0461 1N4828 G. E.VR300Zener diode, 4. 22V, :!:5%400 mw1902-3070 1N749 MotorolaTable 5-B.Checks and Adjustments After Replacement of Semiconductor DevicesReference Function Check Adjust0100 Constant voltage differential amplifierConstant voltage (CV)line and load ~egu lation.0200 Constant current differential amplifierConstant ct:trrent (CC)line and load regulation.0300 Constant Current gating amplifier CC load regulation.Q301 Constant Voltage gating amplifier CV load regulation.•0302. 0303 Error amplifiersCV/CC load regulationTransient response0400 (0401) Series Regulator CV/CC load regulationReference ~oltages.0600, Q601.0602, Q603Reference regulatorOvervoltage trip point. R604R3070700, Q701 Voltage across R7110702SCR controlseries regulator0851, 0852. Meter zero. Voltmeter/ R870,RB65,QBS3Meter amplifiersAmmeter trackingRBSSQBOl, QB02Overcurrent detectorsShort output, ensurethat output goes tozero without damageto series regulator.CRlOO, CRlOl Limiting diodes CV load regulationCR403, CR404Forward bias regulatorVoltage across eachdiode O. 6 to O. 9 volts.CR700-CR703Rectifier bridgeWaveform between 52and 90•5-11CR704-CR707Rectifier bridgeWaveform b~tween 54and 90

Excessive heat or pressure can lift the copper strip from the board. Avoid damage by using alow power soldering iron ( 50 watts maximum) and following these instructions. Copper that liftsoff the board should be cemented in place with a qUick drying acetate base cement bavtng goodelectrical insulating properties.•A break in the copper should be repaired by soldering a short length of tinned copper wireacross the break.Use only high quality rosin core solder when repairing etched circuit boards. NEVER USEPASTE FLUX. After soldering, clean off any excess flux and coat the repaired area With ahigh quality electrical varnish or lacquer.When replacing components with multJple mowiting pins such as tube sockets, electrolytic capacitors,and potentiometers, it Will be necessary to lift each pin slightly, working around thecomponents several times unW it is free.WARNING: If the specific instructions outlined in the steps below regarding etched circUit boardswlthout eyelets are not followed, extensive damage to the etched circuit board will result.1. Apply heat sparingly to lead of componentto be replaced. If lead of component passesthrough an eyeletin the circuit ~- · .··board, applyheat on com- ~ponent side ,.,,-~~~;__,of board. If I.lead of com-\:;ponent doesnot pass --uirough aneyelet, apply beat to conductor side of board.3. Bend clean tinned lead on new part andcarefully insertthrough eye lets orholes in board.C'''''''''''Up;Q!Q ~2. Reheat solder in vacant eyeletand quicklyinsert a small awl to cleaninside of hole.If hole doesnot bavi"iiieyelet, insertawl ora 157 drillfrom conductorside _______of board.4. Boldpartagainstboard(avoidoverheating)and solder leads.Apply heat to companentleads on correctside af boardas explainedin step 1......,•In the event that either the circuit board has been damagedorthe conventional methodisimpractical,use method shown below. This is especially applicable for circuit boards without eyelets.1 •. Clip lead as shown below. 2. Bend prcitrudlng leads upward. Bend leadof new APPLYcomponent SOLDERaround protrudinglead.Apply solderusing a pairof long nose pliers as a heat sink.This procedure is used in the field only as an alternate m•?ans of repair. It is not used withinthe factory.Figure 5-10. Servicing Printed Wiring Boaf'!is••S-12

Table 5-8. Checks and Adjustments After Replacement of Semiconductor Devices (Continued)•CR600, CR601,CRBOO, CRBOl, Rectifier diodesCRS01-CRS04VR600, VR601Reference voltages.Voltage across appro-priate filter capacitorCheck +9. 4V and -6. 2Vreference voltagesTable 5-9. Calibration Adjustment SummaryAdjustment or CalibrationParagraph Control Device••Meter ZeroVoltmeter TrackingAmmeter Trac king•voltage" Programming Current•current" Programming CurrentOvervoltage TripTransient ResponsePreregulator TrackingS-36 ADJUSTMENT AND CALIBRATIONS-37 Adjustment and calibration may be req\liredafter performance testing, troubleshooting, or repairand replacement. Perform only those adjustmentsthat affect the operation of the faulty circuit and noothers. Table S-9 summarizes the adjustments aridcalibrations contained in the following paraqraphs.5-38 METER ZEROS-39 Proceed as follows to zero meter:a. Tum off instrument (after it has reachednormal operating temperature) and allow 30 secondsfor all capacitors to discharge.b. Insert sharp pointed object (pen point orawl) into the small indentation near top of roundblack plastic disc located directly below meter face.c. Rotate plastic disc clockwise (cw) untilmeter reads zero, then rotate ccw slightly in orderto free adjustment screw from meter suspension. Ifpointer moves, repeat steps band c.5-40 VOLTMETER TRACKINGS-41 l'o calibrate voltmeter tracking, p-oceed asfollows:5-38 Pointer5-40 R870 and R8655-42 R855S-44 .R8065-46 R8085·48 R604s-so R3075-52 R7lla. To electrically zero meter, set METERsWitch to highest current position and, With supplyoff and no load connected, adjust R870 until frontpanel meter reads zero.b. Connect differential voltmeter across supply,obs Erving correct polarity.c. Set METER switch to highest voltage rangeand turn on supply. Adjust VOLTAGE control untildifferential voltmeter reads exactly the maximumrated output voltage.d. Adjust R865 until front panel meter alsoindicates maximum rated output voltage.S-42 AMMETER TRACKING5-43 To calibrate ammeter tracking, proceed asfollows:a. Zero meter as described in step a of 5-41.Connect test setup shown on Figure 5-4 leavingswitch Sl open.b. Turn VOLTAGE control fully clockwise andset METER switch to hiqhest current range.c. Turn on supply and adjust CURRENT controlsuntil differential voltmeter reads 1. OVdc.d. Adjust R855 until front panel meter indicatesexactly the maximum rated output current.S-13

5-44 CONSTANT VOLTAGE PROGRAMMING CURRENT5-45 To calibrate the constant voltage programmingcurrent, proceed as follows:a. Connect a 0. l % , 20 watt resistor betweenterminals -S and A4 on rear barrier strip. Resistorvalue to be as follows:Model 6282A 6285A 6286A .6290A 6291A 6296ARes. 2K 4K 4K SK BK l 8Kb. Disconnect jumper between A3 and A4 onrear terminal barrier strip.R806.c. Connect a decade resistance in place ofd. Connect a differential voltmeter between+S and -S and turn on supply.e. Adjust decade resistance box so that differentialvoltmeter indicates maximum rated outputvoltage within the following tolerances:Model 6282A 6285A 6286A 6290A 6291A 6296ATol.(Vdc) :0.2 ::i:0.4 ::t.:0.4 ::t.:0.8 :0.8 ::i:l.2f. Replace decade resistance with resistorof appropriate value in R806 position.5-46 CONSTANT CURRENT PROGRAMMINGCURRENT5-47 To calibrate the constant current programmingcurrent, proceed as follows:a. Connect power supply as shown in Fig. 5-4.b. Remove strap between A6 and A7 (leavingA7 and AS jumpered).c. Connect a O. 1 % , 1/2 watt resistor betweenAl and A7. Resistor value is l!V. (1. SKt. forModels 6290A and 6296A).of R808.d. Connect decade resistance box in placee. Set METER switch to highest currentrange and turn on supply.f. Adjust the decade resistance so that thedifferential voltmeter indicates 1. 0 ::1: O. 02Vdc.g. Replace decade resistance with appropriatevalue resistor in R808 position.5-48 OVERVOLtAGE TRIP5-49 To adjust the overvoltage trip point, proceedas follows:a. Connect differential voltmeter acres s +Sand -S terminals of supply.b. Rotate VOLTAGE controls fully clockwise.c. Turn on unit. Differential voltmetershould read 20% above maximum rated output voltagewithin :!:5%.d. If it does not, turn off supply and connectdecade resistance across R60S in place of R604.e. Adjust decade resistance until differentialvoltmeter reads that indicated in step c.NOTEThe +15.4V reference voltage mustbe kept within ::i:0.5Vdc when adjustingthe decade resistance box.f. Replace decade resistance With r•esistorof appropriate value in R604 position.5-50 TRANSIENT RECOVERY TIMES-51 To adjust the transient response, proceed a.follows:a. Connect test setup as shown in Figure 5-7.b. Repeat steps a through e as outlined inParagraph 5-19.c. Adjust R307 so that the transient responseis as shown in Figure 5-8.5-52 PREREGULATOR TRACKING (60Hz OPERATION)5-53 To adjust the preregulator control circ:uit witha 60Hz ac input, proceed as follows:a. Connect proper load resistor acroiss outputterminals of supply. Resistance value 1to be asfollows:MQQfil. 6282A 6285A 6286A 6290A 6291A 6296ARes. l.n. 4n. 2.n. l 3n. 8.n. 2 o.,..b. Connect DC voltmeter between TP27 andTP90 (across series regulator).c. Turn on supply and adjust VOLTAGIE controlsfor maximum rated output voltage.3 ::i: O. 2Vdc.d. Adjust i71 l so that DC voltmeter reads5-54 PREREGUIATOR TRACKING (SOHz OPERATION)5-55 To adjust the preregulatorcontrol circuitwhe.nthe ac input is from a SOHz source, proceed asfollows:a. Connect load resistor across rear outputterminal of supply. Resistor value to be as follows:Model 6282A 6285A 6286A 6290A 6291A 6296ARes. l.n. 4n 2.n. l 3n. Sn 20.n.b. Connect o.scilloscope (de coupled) acrossseries regulator, T. P. 27 to T. P. 90.c. Disconnect R709 in the SCR control circuit,and connect decade resistance box in its place.d. Rotate CURRENT controls fully clockwiseand turn on supply.e. Decrease resistance of decade resistancefrom normal value of R709 until sawtooth waveformon oscilloscope is symmetrical (amplitude of SOH-zsawtooth waves are equal).f. Replace decade resistance box with appropriatevalue resistor in R709 position.g. Adjust ramp potentiometer R711 for 3.SVdcdrop across series regulator.h. If 3.S volts cannot be obtained, removeR712 (in series with R711) and connect the decaderesistance box in its place.i. Increase value of decade resistance boxfrom normal value of R712 until 3.SVdc drop is obtainedacross series regulator.j. Remove decade resistance and con.nectnew resistance value in R712 position. •5-14

•••6·1 INTRODUCTION6-2 This section contains information for orderingreplacement parts. Table 6-4 lists parts in alphanumericorder by reference designators and providesthe following information:b. Description. Refer to Table 6-2 for abbreviations.a. Reference Designators. Refer to Table 6-l.c. Total Quantity (TQ). Given only the firsttime the part number is listed except in instrumentscontaining many sub-modular assemblies, in whichcase the TQ appears the first time the part numberis listed in each assembly.d. Manufacturer's Part Number or Type.e. Manufacturer's Federal Supply Code Number.Refer to Table 6-3 for manufacturer's name andaddress.f. Hewlett-Packard Part Number.g. Recommended Spare Parts Quantity (RS)for complete maintenance of one instrument duringone year of isolated service.h. Parts not identified by a reference designatorare listed at the end of Table 6·4 under Mechanicaland/or Miscellaneous. The former consistsof parts belonging to and grouped by individual assemblies:the latter consists of all parts not immediatelyassociated with an assembly.6-3 ORDERING INFORMATION6-4 To order a replacement part, address order orinquiry 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 orspecial modification cJ) numbers of the instrument;Hewlett-Packard part number: circuit reference designator;and description. To order a part not listedin Table 6-4, give a complete description of thepart, its function, and its location.Table 6-l. Reference DesignatorsA =assembly E = miscellaneousB = blower (fan) electronic partc =capacitor F = fuseCB = circuit breaker J = Jack, JumperCR = diode K = relayDS = device, signal- L = inductoring (lamp) M = meterSECTION VIREPLACEABLE PARTSpQRsTTable 6-l. Reference Designators (Continued)TBTS=plug V= transistor=resistor=switch VR= transformer X= terminal block Z= thermal switch= vacuum tube,neon bulb,photocell, etc.= zener diode= socket= integrated circuitor networkTable 6-2. Description AbbreviationsA =ampere mfr = manufact.irerac = alternating mod, = modular orcurrent modifiedassy, = assembly mtg =mountingbd =board n = nano= io-9bkt = bracket NC = normally closedcc =degree NO = normally openCentigrade NP = nicke 1-platedcd =card r>. =ohmcoef = c.oefficient obd =order bycomp = composition descriptionCRT = cathode-ray OD =outsidetube diameterCT = center-tapped p = pico= io-12de = direct current P.C. = printed circuitDPDT = double pole, pot. = potentiometerdouble throw p-p = peak-to-peakDPST = double pole. ppm = parts persingle throw millionelect = electrolytic pvr = peak reverseencap = encapsulated voltageF =farad rect = rectifieror =degree nns =root meanFarenheit squarefxd =fixed Si = siliconGe =germanium SPDT = single pole,H =Henry double throwHz =Hertz SPST = single pole,IC = integrated single throwcircuit SS = small signalID = inside diameter T = slow-blowincnd = incandescent tan. = tantulumk = kilo= io3 Ti = titaniumm = mllli = io-3 v =voltM =mega= io6 var = variable11 = micro = io-6 WW = wirewoundmet. =metal w =Watt6-l

CODENO.00629006560085301121012550128101295016860193002107021140260602660027350350803797038770388804009040720421304404047130527705347058200600106004MANUFACTUREREBY Sales Co. , ·Inc.Aerovox Corp.Sangamo Electric Co.s. Carolina Div.Allen Bradley Co.Litton Industries, Inc.Beverly HUls,TRW Semiconductors, Inc.Texas Instruments, Inc.Table 6-3. Code List of ManufacturersADDRESSJamaica, N. Y.New Bedford, Mass.Pickens, S. C.Milwaukee, Wis.Lawndale,Semiconductor-Components Div.Calif.Calif.Dallas, TexasRCL Electronics, Inc. Manchester, N. H.Amerock Corp. Rockford, Ill.Sparta Mfg. Co. Dover, OhioFerroxcube Corp. Saugerties, N. Y.Fenwal Laboratories Morton Grove, Ill.Amphenol Corp. Broadview, Ill.Radio Corp. of America, Solid Stateand Receiving Tube Div. Somerville, N.J.G. E. Semiconductor Products Dept.Syracuse, N. Y.Eldema Corp. Compton, Calif.Transitron Electronic:. Corp.Pyrofilm Resistor Co. Inc.Wakefield, Mass.Cedar Knolls, N. J.Arrow, Hart and Hegeman Electric Co.Hartford, Conn.ADC Electronics, Inc. Harbor City, Calif.Cadde 11 & Bums Mfg. Co. Inc.Mineola, N. Y.*Hewlett-Packard Co. Palo Alto Div.Palo Alto, Calif.Motorola Semiconductor Prod. Inc.Phoenix, Art.zonaWestinghouse Electric Corp.Semiconductor Dept. Youngwood, Pa.t1ltronix, Inc. Grand Junction, Colo.Wakefield EnQr. Inc. Wakefield, Mass.General Elect. Co. ElectronicCapacito~ & Battery Dept. Irmo, S. C.Bassik Div. Stewart-Warner Corp.Bridgeport, Conn.06486 IRC Div. of TRW Inc.Semiconductor Plant Lynn, Mass.06540 Amatom Electronic Hardware Co. Inc.06555 Beede Electrical Instrument Co.06666 General Devices Co. Inc.06751 Semcor Div. Components, Inc.New Rochelle, N. Y.Penacook, N. H.Indianapolis, Ind.Phoenix, Arizona06776 Robinson Nugent, Inc. New Albany, Ind.06812 Torrington Mfg. Co., West Div.07137 Transistor Electronics Corp.Van Nuys, Calif.Minneapolis, Minn.CODENO.0713807263073870739707716079100793308484085300871708730088060886308919090210918209213092140935309922111151123611237115021171112136*Use Code 28480 assigned to Hewlett-Packard Co., Palo Alto, California6-2MANUFACTURER ADDRESSWestinghouse Electric Corp.Electronic Tube Div. Elmira, :~. Y.Fairchild Camera and InstrumentCorp. Semiconductor Div.Mountain View, Calif.Birtcher Corp-. .The Los Angeles, Calif.Sylvania Electric Prod. Inc.Sylvania Electronic SystemsWestern Div. Mountain View, Calif.IRC Div. of TRW Inc. Burlington PlantContinental Device Corp.Burlington, lowaHawthorne, C

Table 6-3, Code List of Manufacturers (Continued)•••CODENO. MANUFACTURER ADDRESS16758175451780317870183241931519701215202222922753239362444624455246552468126982270142848028520288753151431827331733543437942Delco Radio Div. of General Motors Corp,Atlantic Semiconductors, Inc.Kokomo, Ind.Asbury Park, N. J.Fairchild Camera and Instrument CorpSemiconductor Div, Transducer PlantMountain View, Calif.Daven Div. Thomas A. Edison IndustriesMcGraw-Edison Co. Orange, N. J.Signetics Corp. Sunnyvale, Calif.Bendix Corp. The Navigation andControl Div. Teterboro, N. J.Electra/Midland Corp.Fans tee l Meta llurgica 1 Corp.Mineral Wells, TexasNo, Chicago, IlLUnion Carbide Corp. Electronics Div,Mountain View, Calif.UID Electronics Corp. Hollywood, Fla.Pamotor, Inc, Pampa, TexasGeneral Electric Co. Schenectady, N. Y.General Electric Co. Lamp Div. of ConsumerProd, GroupNela Park, Cleveland, OhioGeneral Radio Co. West Concord, Mass.LTV Electrosystems Inc Memcor/ComponentsOperations Huntington, Ind.Dynacool Mfg, Co. Inc. Saugerties, N. Y.National Semiconductor Corp.Hewlett-Packard Co,Heyman Mf;. Co.IMC Magnetics Corp.New Hampshire Div,SAE Advance Packaging,Budwig Mfg, Co.G. E. Co. Tube Dept.Lectrohm, Inc.P, R. Mallory & Co. Ille.Santa Clara, Calif.Palo Alto, Calif.Kenilworth, N. J,Rochester, N. H.Inc.Santa Ana, Calif.Ramona, Calif.Owensboro, Ky.Chicago, Ill.Indianapolis, Ind.42190 Muter Co. Chicago, Ill43334 New Departure-Hyatt Bearings Div.General Motors Corp. Sandusky, Ohio44655 Ohmite Manufacturing Co. Skokie, IlL46384 Penn Engr. and Mfg, Corp.Doylestown, Pa.47904 Polaroid Corp, Cambridge, Mass,49956 Raytheon Co. Lexington, Mass.55026 -Simpson Electric Co. Div, of American562895847458849597306163763743Gage and Machiae Co. Chicago, Ill.Sprague Electric Co. North Adams, Mass,Superior Electric Co, Bristol, Conn,Syntron Div. of FMC Corp.Homer City, Pa.Philadelphia, Pa.New York, N. Y,Ward Leonard Electric Co.Mt. Vernon, N. Y.Thomas and Betts Co.Union Carbide Corp.*Use Code 71785 assigned to Cinch Mfg. Co., Chicago, Ill.CODENO. MANUFACTURER ADDRESS7056370901709037121871279714007145071468Amperite Co. Inc. Union City, N. J.Beemer Engrq, Co. Fort Washington, Pa.Belden Corp. Chicago, Ill.Bud Radio, Inc, Wllloughby, OhioCambridge Thermionic Corp.Cambridge, Mass.Bussmann Mfg. Div. of McGraw &Edison Co. St. Louis, Mo.CTS Corp. Elkhart, Ind.LT. T. Cannon Electric Inc.71590 Globe-Union Inc.Los Angeles. caw.Centralab Div. Milwaukee, Wis.71700 General Cable Corp. ComishWire Co, Div, Williamstown, Mass.717 07 Coto Coil Co, Inc. Providence, R. I.71744 Chicago Miniature Lamp Works717 85 Cinch Mfg. Co. and HowardChicago, Ill.B. Jones Div. Chicago, Ill.71984 Dow Coming Corp. Midland, Mich.72136 Electro Motive Mfg, Co, Inc.Willimantic, Conn.72619 Dialight Corp. Brooklyn, N. Y.72699 General Instrument Corp. Newark, N. J,7 27 65 Drake Mfg. Co. Harwood Heights, Ill.72962 Elastic Stop Nut Div. ofAmerace Esna Corp. Union, N. J,72982 Erie Technological Products Inc. Erie, Pa,7 3096 Hart Mfg. Co. Hartford, Conn.73138 Beckman Instruments Inc.Helipot Div, Fullerton, Calif.73168 Fenwal, Inc. Ashland, Mass.73293 Hughes Aircraft Co. ElectronDynamics Div. Torrance, Calif.73445 Amperex Electronic Corp.73506 Bradley Semiconductor Corp,Hicksville, N. Y.New Haven, Conn.73559 Carling Electric, Inc, Hartford, Conn.73734 Federal Screw Products, Inc.Chicago, Ill.74193 Heinemann Electric Co, Trenton, N. J.74545 Hubbell Harvey Inc. Bridgeport, Conn.74868 Amphenol Corp. Amphenol RF Div.Danbury, Conn.74970 E. F. Johnson Co. Waseca, Minn,75042 IRC Div. of TRW, Inc. Philadelphia, Pa.75183 *Howard B. Jones Div. of CinchMfg, Corp, New York, N. Y.75376 Kurz and Kasch, Inc. Dayton, Ohio75382 Kilka Electric Corp. Mt. Vernon, N. Y.75915 Uttlefuse, Inc. Des Plaines, Ill.76381 Minnesota· Mining and Mfg. Co.St. Paul, Minn.76385 Minor Rubber Co. Inc. Bloomfield, N. J,76487 James Millen Mfg, Co. Inc.Malden, Mass.76493 J. W, Miiier Co. Compton, Calif,6-3

Table 6-3. Code List of Manufacturers (Continued)CODENO.76530768547706877122771477722177252773427763077764781897845278488785267855378584791367930779727799638003180294810428107381483817518209982142822198238982647828668287782893830588318683298833308338583501MANUFACTURER ADDRESSCinch City of Industrv, Calif.Oak Mfg. Co. Div. of OakElectroiNetics Corp. Crystal Lake, Ill.Bendix Corp., Electrodynamics Div.No. Hollywood, Calif.Palnut Co. Mountainside, N. J.Patton-MacGuyer Co. Providence, R. LPhaostron Instrument and Electronic Co.South Pasadena, Calif.Philadelphia Steel and Wire Corp.Philadelphia, Pa.American Machine and Foundry Co.Potter and Brumfield Div. Princeton, Ind.TRW Electronic Components Div.Camden, N. J.Resistance Products Co. Harrisburg, Pa.Illinois Tool Works Inc. Shakeproof Div.Elgin, Ill.Everlock Chicago, Inc. Chicago, Ill.Stackpole Carbon Co. St. Marys, Pa.Stanwyck Winding Div. San FernandoElectric Mfg. Co. Inc. Newburgh, N. Y.Tinnennan Products, Inc. Cleveland, OhioStewart Stamping Corp. Yonkers. N. Y.Waldes Kohinoor, Inc. L: I. C., N. Y.Whitehead Metals Inc. New York. N. Y.Continental-Wirt Electronics Corp.Philadelphia, Pa.Zierick Mfg. Co. Mt. Kisco, N. Y.Mepco Div, of Sessions Clock Co.Morristown, N. J.Bourns, Inc. Riverside, Calif.Howard Industries Div. of Msl Ind. Inc.Racine, Wisc.Graybill, Inc. La Grange, IllInternational Rectifier Corp.El Segundo, Calif.Columbus Electronics Corp. Yonkers, N. Y:Goodyear Sundries & Mechanical Co. Inc.New York, N. Y.Airco Speer Electronic ComponentsDu Bois, Pa.Sylvania Electric Products Inc.Ele.ctronic Tube Div. ReceivingTube Operations Emporium, Pa.Switchcraft, Inc, Chicago, Ill.Metals and Controls Inc. ControlProducts Group Attleboro, Mass.Research Products Corp. Madison, Wis.Rotron Inc. Woodstock, N. Y.Vector Electronic Co. Glendale, Calif.Carr Fastener Co. ·Cambridge, Mass.Victory Engineering Corp.Springfield, N. J.Bendix Corp. Electric Power Div.Eatontown, N. J.Herman H. Smith, Inc. Brooklyn, N. Y.Central Screw Co. Chicago, Ill.Gavitt Wire and Cable Div. ofAmerace Esna Corp, Brookfield, Mass.CODENO.835088359483835838778417184411866848683887034872168758587929881408824590634907639134591418915069163791662919299282593332934109414494l54942229526395354957129598796791974649770298291984109897899934MANUFACTURER ADDRESSGrant Pulley and Hardware Co,Burroughs Corp. ElectronicWest Nyack, N. Y.Components Div. Plainfield, N. J.U. S, Radium Corp. Morristown, N. J.Yardeny Laboratories, Inc.New York, N. Y.Arco Electronics, Inc, Great Neck, N. Y.TRW Capacitor Div. Ogallala, Neb.RCA Corp. Electronic ComponentsHarrison, N'. J.Rummel Fibre Co. Newark, N.J.Marco & Oak Industries a Div. of OakElectro/netics Corp. Anaheim; Calif.Philco Corp, Lansdale Div, Lansdale, :Pa.Stockwell Rubber Co. Inc.Philadelphia, Pa.Tower-Olschan Corp, Bridgeport, Conn.Cutler-Hammer Inc. Power Distributionand Control Div. Lincoln PlantLincoln, Ill.Litton .Precision Products Inc, USECODiv. Litton Industries Van Nuys, Calif.Gulton Industries Inc. Metuchen, N. J.United-Car Inc. Chicago, Ill.Miller Dial and Nameplate Co.Radio Materials Co.Augat, Inc.Dale Electronics, Inc.Elco Corp.El Monte, Calif.Chicago, Ill.Attleboro, Mass,Columbus, Neb.Willow Grove, Pa.Honeywell Inc. Div. Micro SwitchFreeport, IU.Whitso, Inc. Schiller Pk. , Il.l.Sylvania Electric Prod.conductor Prod. Div,Es sex Wire Corp. StemcoInc. Semi­Wobum, Mass,Controls Div. Mansfield, Oh:loRaytheon Co. Components Div.Ind. Components Oper. Quincy, Mau.Wagner Electric Corp,Tung-Sol Div. Livingston, N. r.Southco Inc. Lester, Pa.Leecraft Mfg. Co. Inc. L. I. C., N. Y.Methode Mfg. Co, Rolling Meadows, Ill.Bendix Corp. MicrowaveDeVices Div.Weckesser Co, Inc.Amphenol Corp, AmphenolFranklin, Ind.Chicago, Ill.Controls Div, Janesville, Wl!i,Industrial Retaining Ring Co.Irvington, N. J.IMC Magnetics Corp, Eastern Div.Westbury, N. Y.Sealectro Corp. Mamaroneck, N, Y,ETC Inc. Cleveland, Ohil:>International Electronic Research Corp.Burbank, Calif.Renbrandt, Inc. Boston, Mass.•••6-4

•ClOO•801,•6296ARefe.rence Mfr. Part 4t Mfr. ~Designator Description Quantity or Type Mfr. Code Stock No. RSfxd. film o. Q82µf 2oov 1 192P82392 Sprague 56289 0160-0167 1C200 fxd, film 0.0047!J.f 200V 1 192P47292 Sprague 56289 0160-0157 1C300 fxd, film 0.22µf 80V l 192P2249R8 Sprague 56289 0160-2453 1C302, 301, 303 fxd, film 0.0022µ.f 200V 3 192P22292 Sprague 56289 0160-0154 1csoo fxd, elect 10, OOOµf 75V l D39062 HI.AB 09182 0180-1924 1CSOl fxd. paper O.lid 400V l 160Pl0494 Sprague 56289 0160-0013 lC600 fxd, elect 325µ.f 35V 1 034656 HI.AB 09182 0180-0332 lC601, 602, 702.801 fxd, elect 5µ£ 65V 4 033689 HI.AB 09182 0180-1836 1C700 fxd, elect lµf 35V 1 1500105X903SA2 Sprague 56289 0180-0291 lC701 fxd, elect lid SOV l 30Dl05G050BA4 Sprague 56289 0180-0108 1C703 fxd, film O,lµf 200V 1 192Pl0492 Sprague 56289 0160-0168 10000 fxd, elect 1500µ.f 40V 1 038733 HI.AB 09182 0180-1894 1C802 fxd, elect 10µ£ lOOV 1 30Dl06Gl00DC2Ml Sprague 56289 0180-0091 1C803 fxd, elect 1600µ£ 70V 1 041655 HIAB 09182 0180-1895 10804 NOT ASSIGNEDC805 fxd, elect 4. 7µ.f 35V 1 150D475X9035B2 Sprague 56289 0180-0100 1C900 fxd, elect 20µf 50V l 30D206GOSODC4 Sprague 56289 0180-0049 1CRl00-102, 200,300, 301. 500,700-711, 802.807. 808, 900,901 Si. diode 200ma 200prv 24 HI.AB 09182 1901-0033 9CR400, 501, 503,809 Si. rect 3A@7soc 200prv 4 MR1032B Motorola 04713 1901-0416 4CR401, 403, 404,600,601,800,902, .Si. rect 500ma 200prv 8 1N3253 · R.C.A. 02735 1901-0389 6CR402, 602, 803,804.805.806 Si. diode 200ma 15prv 6 HI.AB 09182 1901-0461 6CR502, 504 SCR 8 amp 200prv 2 2N3669 R. C.A. 02735 1884-0019 2Fl Fuse cartridge SA 1 312005 Littlefuse 75915 2110-0010 5Ql00,200 Si. NPN diff. amp, 2 HI.AB 09182 1854-0229 2Q300. 301. 601.602.603 Si. NPN 5 4JX16Al014 G.E. 03508 1854-0071 5Q302, 700, 701,801.802 ·Si. NPN 5 2N3417 G.E. 03508 185 4-0087 50303,400 Si. ~PN power 2 HLA.B 09182 1854-0225 20401 'NOT USEDQ600 Si. PNP 1 40362 R.C.A. . 02735 185 3-0041 10702. 800, 850,852,853 Sl. PNP 5 2N2907A Sprague 56289 1853-0099 50851 Si. NPN diff. amp, 1 HI.AB 09182 1854-0221 10854 NOT ASSIGNEDRl00,202,819 fxd, met. film 160Kn.:U% l/8w 3 Type CEA T-0 I. R. C. 07716 0698-5092 1RlOl. 201. 820 fxd, met. film 61. 9Kn.:1:l % l/Bw 3 Type CEA T-0 I. R. C. 07716 0757-0460 1Rl02,108.204 fxd, met. film 432Kn.:1:l % l/Bw 3 Type CEA T-0 I. R. C. 07716 0757-0480 1R103,306,815 fxd. comp lKn. :1:5% !w 3 EB-1025 A.B. 01121 0686-1025 1Rl04 fxd, ww 490.n ~5% 3w 20ppm 1 242E-4915 Sprague. 56289 0811-1801 lRlOS.206 fxd, met. film 33. OKn. :1:1 % l/Bw 2 Type CEA T-0 I. R.C. 07716 0698-5089 1Rl06.200. 203 · fxd, met. film 1.5Kn:t:l% Vaw 3 Type CEA T-0 I. R. C. 07716 0757-0427 lRl07, 205 fxd, met. film 47.SKn.:1:1% VBw 2 Type CEA T-0 I. R. c. 07716 0757-0457 l6-S

Reference Mfr. Part# Mfr.Designator Descrtetion Quan tit~ or Tm Mfr, Code Stock No, RSR300 fxd. comp 330Kn. :i:S% !w 1 EB-3345 A.B. 01121 0686-3345 1R301 bed. comp 39.n. :i:5% tw 1 EB-3905 A.B. 01121 0686-3905 1·R302, 303 fxd. comp 36Kn. :i:S% !w 2 EB-3635 A.B. 01121 0686-3635 1R304 fxd. comp 75.n. :1:5% !w 1 EB-7505 A.B. 01121 0686-7505 1R305 fxd. comp 6. 2Kn. :1:5% !w 1 EB-6225 A.B. 01121 0686-6225 1R307 var. ww lOKn. 1 Series 70 C. T.S. 71450 2100-0092 1R308 fxd. comp 3Kn. :i:5% tw 1 EB-3025 A.B. 01121 0686-3025 1•R309 fxd, comp 150.n. :i:5% 40w 1 405/817 MTG W.L. 63743 0811-1924 lR310 fxd. comp 47Kn. :1:5% iw l EB-4735 A.B. 01121 0686-4735 1R311 fxd. WW 6.8.n. :i:5% 1 Type BWH I. R. C. 07116 0811-1676 1R312.811.812 fxd. ww 100.n. :1:5% }w 3 EB-1015 A.B. 01121 0686-1015 lR313 fxd. ww lOKn. :t::5% tw l .EB-1035 A. B. 01121 0686-1035 lR400 Strap 1R401 LEAVE OPENR500 fxd. WW 800.n. :1:5% 10w 1 lOXM W. L. 63743 0811-0944 lR501,502 fxd. comp 47.n. :1:5% iw 2 EB-4705 A.B. 01121 0686-4705 1R503 fxd, comp 820,... :1:5% jw 1 EB-8215 A.B. 01121 0686-8215 1R600 fxd, comp lOOKn. :i:5% jw 1 EB-1045 A. B. 01121 0686-1045 1R601 fxd, met. film !Kn. :1:1 % tw 1 Type CEB T-0 I. R. C. 07716 0757-0338 1R602.871 fxd. met. film 1. 33Kn. :t:l % tw 2 Type CEB T-0 I.R.C. 07716 0698-3134 lR603 fxd, met. film 2Kn. :t:l % tw 1 Type CEB T-0 I. R. C. 07716 0757-0739 1R604,806.808 fxd. comp SELECTIVE :t:5% }w 3 Type EB A.B. 01121 lR605, 608. 609.610 fxd. met. film 6.2K.n. :t:l% tw 4 Type C.EB T-0 I.R.C. 07116 0698-5149 lR606 fxd, met. film 9.31Kn.:1:1%tw l Type CEB T-0 I. R. C. 07116 0698-3283 1R607 fxd. met. film 560µ :1:1 % tw 1 Type CEB T-0 I.R.C. 07716 0698-5146 lR611 bed, WW 390.n. :1:5% 3w 1 242E-3915 Sprague 56289 0811-1799 lR700 fxd. met. ox 270.n. :t::5% 2w 1 Type C42S Coming 16299 0698-3629 1R701 fxd, comp 24n. :1:5% jw l EB-2405 A.B. 01121 0686-2405 1R702 fxd, WW 2.4K.n. :1:5% 3w 1 242£-2425 Sprague 56289 0811-1807 1R703,707 fxd. comp 3.9Kn. :t::5% !w 2 EB-3925 A.B. 01121 0686-3925 1R704 fxd. comp 9.lKn. :1:5% tw l EB-9125 A.B. 01121 0686-9125 lR705 fxd, comp llOKn. :1:5% iw l EB-1145 A.B. 01121 0686-1145 lR706 fxd, comp 4.7.n. :t5% lw l GB-0475 A.B. 01121 0689-0475 1R708 fxd. comp 4. 3Kn. :1:5% !w 1 EB-4325 A.B. 01121 0686-4325 1R709 fxd. comp 8. 2Kn. :1:5% -fw l EB-8225 A.B. 01121 0686-8225 1R710 fxd, comp 1.lM.n. :i:5% !w 1 EB-1155 A. B. 01121 0686-1155 1R711 var. ww SK.n. 1 Type 110-F4 C. T.S. 11236 2100-1824 1R712 fxd. comp 12Kn. ±5% !w 1 EB-1235 A. B. 01121 0686-1235 1R713 fxd, comp 270Kn. :i:5% !w l EB-2745 A.B. 01121 0686-2745 1R800 fxd, WW 0. 33.n. ±5% 40w 1 HI.AB 09182 0811-1953 1R805 fxd. WW 3K.n. :1:5% 3w 1 242E-3025 Sprague 56289 0812-0010 1R807 fxd. ww lOKn. ±5% 3w 1 242£-1035 Sprague 56289 0811-1816 lR809.810 var. ww l.8K.n. - 20.n.DUAL POT 2 HI.AB 09182 2100-0995 1R813,814 var. ww 22K.n.- 2001\.DUAL POT 2 HI.AB 09182 2100-0998 1R816 fxd. comp 43K.n. :t:S% iw 1 EB-4335 A.B. 01121 0686-4335 . 1R817 fxd, comp 62.n. ±5% lw 1 EB-6205 A.B. 01121 0686-6205 1R818 fxd. comp 27Kn. :1:5% tw 1 EB-2735 A. 8. 01121 0686-2735 1R821 fxd. met. film 68. lKn. :i:l % V8w 1 Type CEA T-0 I. R. C. 07716 0757-0461 1R822 fxd. comp 82K.n. :1:5% jw l EB-8235 A.B. 01121 0686-8235 1R823 fxd. met. film 15Kn. ::U% V8w 1 Type CEA T-0 I.R.C. 07716 0757-0446 1R824 fxd, comp 15Kn. :t5% }w 1 EB-1535 A.B. 01121 0686-1535 1R825 fxd. met. ox 160.n. :t:5% 2w l Type C42S Coming 16299 0698-3625 1R826 fxd. comp 3.3Kn. :1:5% !w 1 EB-3325 A.B. Oll21 0686-3325 1R827 fxd, WW 3.n. ::!::5%3w 1 242E3R05 Sprague 56289 0811-1224 16296A6-6••

•R828•T801•Reference Mfr. Part .ft Mfr.Designator Descrietion Qyantit:t'. orT~e Mfr, Code Stock No, RSfxd. comp 680Kn. :5% !w 1 EB-6845 A.B. 01121 0686-6845 1RBSO fxd. met. film 61.9Kn. :i:l% vaw 1 Type CEA T-0 I. R.C. 07716 0757-0460 1R851. 854. 856,859 fxd. met. film 900.n. :l:l % vaw 4 Type CEA T-0 I. R.C. 07716 0757-1099 lR852.853 fxd, met. film 100.n. :1:1 % l/8w 2 Type CEA T-0 I. R. C. 07716 0757-0401 1R857 fxd, met. film S.2Kn. :1:1% tw 1 Type CEB T-0 I. R. C. 07716 0698-5148 1R858 fxd, met. film 9. 31 Kn. :i:l % iw l Type CEB T-0 I. R. C. 07716 0698-3283 1R860,863 fxd, met. film 365.n. :l:l % iw 2 Type CEB T-0 I. R. C. 07716 0757-0723 1R864, 867. 861,862 fxd, met. film 3.40Kn. :1% lw 4 Type CEB T-0 I. R. C. 07716 0698-4642 lR866 fxd, met. film 750.n. :l:l % vaw 1 Type CEA T-0 I. R. C. 07716 0757-0420 lR868,869 fxd. met. film 36.5Kn. :i:l % tw 2 Type CEB T-0 I. R.C. 07716 0757-0765 lR870 var. WW lOKn. 1 Type ll0-F4 C. T. S. 11236 2100-0396 lR872 fxd. met. film 2Kn. :1:1 % vaw l Type CEA T-0 I. R. C. 07716 0757-0283 1R900 fxd, comp 39Kn. :!:5% !w l EB-3935 A. B. 01121 0686-3935 1R901 fxd, comp 180Kn. :i:5% jw l EB-3935 A. B. 01121 0686-1845 1R902 fxd, comp 3Kn. :i:S% !w l EB-3935 A.B. 01121 0686-3025 1R903 fxd, comp 33Kn. :i:5% !w l EB-3935 A. B. 01121 0686-3335 lSl Switch PL. Lt. (red) ON/OFF l 54-61681-26AlH Oak 87034 3101-0100 152 Switch Rotary (meter)3 pole 4 position 1 HIAB 09182 3100-1910 lT700 Pulse Transformer 1 HIAB 09182 9100-1824 1T800 Power Transformer llSV 1 HIAB 09182 9100-1846 lT800 Power Transformer 230V{Special for 230V operationonly) HIAB 09182 9100-2141Bias Transformer l HLAB 09182 9100-1832 1VR300 Diode, zener 4.22V :i:5%400MW l HLAB 09182 1902-3070 lVR600 Diode, zener 9. 4V :5 %500MW 1 1N2163 U.S. Semcor 06751 1902-0762 lVR601 Diode, zener 6. 2V :i:5% l 1N821 N. A. Electric 06486 1902-0761 lSide Chassis - right l HIAB 09182 5000-6098Side Chassis - left l HIAB 09182 5000-6099Chassis - rear 1 HLAB 09182 5000-6103Panel - front 1 HIAB 09182 5000-6100Heat sink - diode 1 HIAB 09182 5000-6101Heat sink - SCR l HIAB 09182 5000-6102Cover 2 HI.AB 09182 5000-6104Guard - angle 1 HIAB 09182 5020-5540Meter Jt" DUAL SCALE0-70V 0-4A l HI.AB 09182 1120-1146 lMeter bezel l mod 1 HIAB 09182 4040-0294 1Meter spring 4 HIAB 09182 1460-0256 lFuse holder 1 342014 Littlefuse 75915 1400-0084 lLoe kw asher 1 1224-08 Shake proof 78189 2190-0037 lNut 1 903-12 Littlefuse 75915 2950-0038 1Washer - neoprene l 901-2 Llttlefuse 75915 1400-0090 lBinding post (maroon} l DF21 Mn HIAB · 09182 1510-0040 1Binding post {black) 2 DF21 BC Superior 58474 1510-0039 1Rubber feet 4 MB-SO Stockwell 87575 0403-0088 1Knob YB dia. black l HI.AB 09182 0370-0084 l6296A6-7

ReferenceDesignator DescriptionKnob pointer s/8 diaKnob ! dia redBarrier stripLine cord 7!' PH 151Strain reliefMica washerMica washer l" diaCapacitor clamp 3" diaMica washer s/8 diaFastener CU-type)Cable clamp YB I. D.Cable clamp t I. D.Delrin bushingDe lrin bushingPem nuts -#8-32Pem nuts *6-32Jumper (barrier strip)Handle 8" black(color no. Y-12561)Mfr. Part iQuantity or Type221ll24l2921624891KH-4096SR-SP-17344586-2A6-32T4-6T4-4CIA-832-2CIA-632-2422-13-110137835Mfr.Mfr. Code Stock N'o. RSHI.AB 09182 0370-0101 1HIAB 09182 0370-0179i.HI.AB 09182 0360-1:~34Beldon 70903 8120-0()50 lHeyco 28520 0400-0013 lReliance 08530 0340-0174 1Reliance 08530 2190-0'.710 lSprague 56289 0190-1~n3 lReliance 08530 2190-0:708 1Tinnerman 89032 2Whitehead 79307 1400-0:332 lWhitehead 79307 1400-0330 1HIAB 09182 0340-0169 2HI.AB 09182 0340-0171 1Penn. Eng. 46384 0590-0.395 1Penn. Eng. 46384 0590-0393 2Cinch 71785 0360-1143 2HI.AB 09182 1440-0042 1OPTION 07:Voltage 10-Tum Potentiometer1Series 8400I. R. C. 07716 2100-186'.7 1OPTION 08:Current 10-Tum Potentiometer1Series 8400I.R.C. 07716 2100-202!9 1OPTION 09:Voltage/Current 10-Tum PotVoltage 10-Tum PotentiometerCurrent 10-Tum Potentiometer111(Includes:)Series 8400Series 8400I. R. C. 07716 2100-1867 ~I.R.C. 07716 2100-2029 1OPTION 13:Voltage Decadial ControlVoltage 10-Turn PotentiometerDecadial Control111(Includes:)Series 8400RD-411I. R. C. 07716 2100-1867 1I. R. C. 07716 1140-0020 1OPTION 14:Current Decadial ControlCurrent l 0-Tum PotentiometerDecadial Control111(Includes:)Series 8400RD-411I. R. C. 07716 2100-2029 1I. R. C. 07716 1140-0020 l•6296A6-8

•fLl V V V-117V /'- /'-----: •l--a.33M8-tA. TEST POINT 53 B. TEST POINT 54 C. UST POINT 59J'NOTE 4l--8.33MS--I 8.UMSD. TEST POINT 56 £. TEST POUIT 47 F. TUT POINTS 46 • 45•G. TEST POINT SZNO!ES: 1. ALl. WAVEFORMS TAKEN WITH llSVAC. 60Kz, SDIGLE·P~ INPUT AT MAXIMUM RATED Ot1TPl1T VOLTAGE AND NO LOADCONNECTED. AMPLITUDES ARE TYPICAL •IOS.Z. OSCIUOSCOPE DC COVPtED AND RUtRl:NCED TOT. P. 90 UNUSS OTHERWISE INDICATl:D.3. WAVEFalMS ARE NOT DRAWN TO SCAIL4. AMPLITUDE or WAVEFORM AT T. '· 47 VARIES WITH DlrrtRENT MODELS AS FOLLOWS:MODEL NO. 6282.lVOLTAGE +ISV6285.l+17V6216" 62901. 6Z91A 6296"+ISV +ZOV +17V +zov•

••~~I"'SAs.s.ztso1ql00-18~2 C.IZ 60CI I1 II I®I~rle~I14!)13y_~4creioof!?I I .l.; 0.1.,,:fI IleooJmTBOI40Vv®-1.zvjNOTE~~I ....IR EF.ERE-NCEIC.~80'2.IS 4li700•••l. 'llMl'BON MODEl. 269 OR IQUIVAl&NT2. U5VAC INPUTCR303l"71ZR"1ro-M1,1.MEG...----A'f WAXJMUM RA.TED OUTPUT WITH NO LOAD CONNtC'ftD. CUUENtCOJC1ROl,I SHOUl.D BE TUaNZJJ ruLl.Y a.oa:ww;.12.7£.fll'H:i::i,c:Vaw,11.CJ.401t.&17~··rC.t40"-R8l'3.3KCR8012. i.LL. Ef;~IST"Of!~ A.EeC&fSI~GATING!METERING]~. 2eF. 'yo1..TACa.e,.:> MEA~ut:ED ·AT u;.,,, r...1J.Je , ~o 1..0AP. LVOLT~GE INPUT'jCURRENT INPUT]~ F.P.-SR61&Y 100--0{-s1~~IOYTL-Model 6296A, Schematic Diagram7. T DE"N~S -..Lo~IAIA&. VALUE', SLEC.TE.c--u· ~Toe:Y U£ OPT~tJM Pit.~oeM~Nce6. - - - Dt+i0TE• C.vE.lte.uT "5.l~frJA.&. \ ---- DENOTe$. VO&..TA

•••Ii3 ON M00EL5 r.Z82A, C:.Z85A, G>Z8r.A AND r.zq1A, CR400.CR501.CR503, AND CRSoqMOUNTED ON HEAT 51NK5 ~OT PRINTED CIRCUIT BOARD.4. ON MODELS r.zqoA AND C:.Z~C:.A, CR400, CR501, CR~3, CR80'7 AREMOUNTED ON PRINTED CIRWIT SOARD NOT HEAT 51NK55. ON MODEL5

I...,I II '~I1I. ....,IIII! .,...,.,I~..,!@-.__I OAS0 A70 A60 AS~'~I -T ~ ,-.:.o+..0 :'.lIR309r-;:---19\---- iu--~ItO\TJOO~~~ 1 ~5:;:0 @.)../ . 0 i(II r-/.""~ II I A\11 3I 011 rr::--:.\\\\ CR504I ...___..,,;~ \ •/~ ~0I J/t~rr::--:.\\1I11.,I 0 A2I o+sI OAl1e1 I1NOTE:I. ~~~:::; ~~T~~~ t>~o:E:o::~~ lZ. A.L.L. Ti!AJJ~IST-'C. 8AS.E~ FACE CorowAtb~ TME ~•Ul-IT OF ~o•t:.D. ( IE.:W:C.EPT OTHEC.W~NOTEO,3. ON M00£LS G.282A, C.tSSA, c.ze~A AND c;.rq1A, CR~OO,CR'SOl.CR'!K>!, ANO CR801MOUNTED ON HEAT 51NK!5 NOT PRINTED CIRCUll" BOARD.•. ON MODELS iotqoA ANO iozqi;.A, CR

APPENDIX AOption 11, OVervoltaqe Protection "Crowbarn•D~CRIPTION:This option is installed in DC Power Supplies, 6282A, 6285A, 6286A, 6290A, 6291A, and 6296A,and tested at the factory. It consists of a printed circuit board, screwdriver-type front panelpotentiometer, and six wires that are soldered to the main power supply board.The crowbar monitors the output voltaqe of the power supply and fires an SCR that effectivelyshorts the output when it exceeds the preset trip voltage. The trip voltage is determined by thesetting of the CROWBAR ADJUST control on the front panel. The trip voltage range is as follows:Model 6282A 6285A 6286A 6290A 6291A 6296ATrip Voltage Range l-13V 2-22v 2-22V 5·42V S-42V 6-66VTo prevent transients from falsely tripping the crowbar, the trip voltage must be set higher thanthe power supply output voltage by the following margin: 7% of the output voltage +lV. Themargin represents the minimum crowbar trip setting for a given output voltage: the trip voltagecan always be set higher than this margin.•OPERATION:1. Tum the CROWBAR ADJUST fully clockwise to set the trip voltage to maximum.2. Set the power supply VOLTAGE control for the desired crowbar trip voltage. To prevent falsecrowbar tripping, the trip voltage should exceed the desired output voltage by the followingamount: 7% of the output voltage +lV.3. Slowly turn the CROWBAR ADJUST ccw until the crowbar trips, output goes to OV or a smallpositive voltage.4. The crowbar will remain activated and the output shorted until the supply is turned off. Toreset the crowbar, tum the ·supply off, then on ••MPB-5A-1

Table A-1. Replaceable PartsClREF.DE SIG.CRl-4CR6CR7Ql02Q3RlR2R3R4R6R7RBR9RlORllRl2Rl3TlVRlDESCRIPTIONfxd, film .l1o1-F 200VdcDiode, Si. 200rnA 200p"rvRe ct. Si. l 2A 1 OOprvSCR 8A 200prvSS NPN Si.SS NPN Si.SS PNP Si.fxd, comp 750.n. :1:5% twfxd, comp lOKn. :1:5% twfxd, comp 200Kn. :1:5% t Wfxd, comp 3.9Kn. ::1:5% twfxd, comp 4.7,,. :1:5% !Wfxd, comp 47.n. :1:5% twfxd, met. ox. 180.n. :5% 2Wfxd, met. film 2Kn. :i:l % l/8Wfxd, comp 3.3Kn. :1:1% l/BWvar. WW 22Kn. :1:10% 2Wfxd, WW 0.5.n. :1:5% SWfxd, comp 200Kn. :5% twPulse TransformerDiode, zener S,62V :1:5%TO1411111111l11l11111llMFR. PART NO.192Pl04921N485B1Nl200A2N36692N27142N3417TZ173EB-7515EB-2045EB-1035EB-3925EB-47G5C425Type C42SType CEA T-0242£3325EB-20451N3512MFR. HPCODE PART NO. RS56289 0160-0168. 109182 1901-0033 402735 1901-0002 102735 1884-0019 103508 1854-0027 103508 1854-0087 l56289 1853-0099 101121 0686-7515 101121 0686-2045 101121 0686-1035 101121 0686-3925 101121 0698-0001 116299 0698-3626 l16299 0698-3626 107716 0757-0283 l56289 0811-1809 109182 2100-185 0 109182 0811-1848 101121 0686-2045 109182 9100-1824 107716 1902-3104 lMISCELIANEOUSBushing, PotentiometerNut, HexPrinted Circuit Board Assembly,Includes ComponentsPrinted Circuit Board, BracketModified Front Panel,Includes Components1111109182 1400-005209182 2950-003409182 06296-6002109182 5000-622509182 06296-600036296AA-2•

•. - --.,Oba ..DC POWER SUPPLY-Hti-A---.FROM TPllO-----+----~+~ 4VFROllTP44 C•15vr.;.·---t----;;::;;;::;;;;;::::::::::;;::::;;::::::::::::::;;::;;::::::::::::::::::::::::::::::::::::::::;;----,----,~Rl20.$U'J..5WCR6+15.4Y•1750112ZOOK114:S9KCR7•CR4CAI-s©-OUT0RllUIC~ ....... ______ .... _____________________ __NOTES:I. ALL RESISTORS ARE 1111 OHMS. 112 W, !~"­UNLESS OTHERWISE NOTED.Z. ALL CAPACITORS ARE IN ltlCROl'ARADSUNLESS OTHERWISE NOTED.CIRCUIT PATENTS APPLIED FOR LICElllSE TO USEMUST BE 08TAINEO IN WRITllllG FllOll "EWLETT­PACURD CO. ttARR 150111 DIVISIONFigure A-1. Model 6296A Over-Voltage Protection Crowbar•A-3

F//~ HEWLETT'~f:.a PACKARDPrimed in CSAOrder Part Number06296-9000 IE l 2M1-l • I 090Manufacturing Part !\umber06296-900011111111111111111111111111111111111111111111111111111111111111 llll