POWER DESIGNS 6050 Instruction manual

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TECHNICALDATA
MODEL6050
MULTI-RANGE DC POWERSOURCE
0-7Vat5A
0-15V at3A
0-25Vat2A
0-50Vat 1A
0-60Vat0.5A
MODEL6050 UNIPLY™
is a regulatedDC power sourcethat functionallyre-
placesfive conventional power supplies.It utilizes a
new regulator technique which provides additional
featuresnot availablein standard instruments.
Outputvoltageandcurrent rangescoverabroad spec-
trumof laboratory requirementsforboth digitaland
analog applications.
Rangingistransient-freeand automaticwith changes
in loadandthesettingofvoltageandcurrent controls.
Operationis completely electronic, without relaysor
manual switching.
The RFI-free regulator system employs linear circuits
only.NoSCR's,switchingtransistorsorhigh frequency
techniquesare utilized.
Power output capabilityofthe supply increaseswith
increasingAClinevoltage.Uptotwice ratedoutputis
"Patents appliedfor
POWER DESIGNSINC.
1700 SHAMESOR.• WESTBURY, l\l. Y.11590
SIS EOgewood 3-6200 TWX: 510-828-6561
availableatline voltagesover105volts. Useful regu-
lated outputat reduced levelsis availabledownto a
linevoltageof85volts.
A flashing panel indicator signalslossof regulation
whenload demandsarein excessof control settings
or theACline voltageistoolowto support increased
output levels.
The supplymaybe operated continuouslyintoan
overloador short circuit without damage.
Regulator efficiencyis superiorto conventional,wide
voltage range, dissipativetype systems.
Portableand light,the Model6050is designedfor
laboratory benchorrackuse.A bail/carrying handle
assembly permits tiltingofthe front panelfor viewing
ease. 5
lA"
panel adaptersare availablefor assem-
blingoneortwo unitsina standard19" rack.
SERIALNO: 70-3
POWER DESIGNS PACIFIC INC.
33B1 MIRANDAAVE.• PA L O ALTO,CAL. 94306
415-321-6111TWX: 910-373-1251

pd
TECHNICALDATA
MODEL6050
DESIGN FEATURES
• Concentric coarseandfinevoltage controlswitha reso-
lutionof3 millivolts.
•Dual range 0.5/5.0 ampere current limiter. Meter range
shifts automatically.
• Remotevoltage programmingat500ohms/volt.
• Remote sensingof output voltage.
• Frontandrear access output terminals.
• Parameter specifications basedon anticipated perfor-
manceafterfiveyearsofservice.
• Semiconductors processed undera "predictable relia-
bility" programto insurelonglife expectancy.This
program includes source codingofall devices,100%
incoming inspectionand measurementof parameters
beyond operating regionsto expose channelingphe-
nomena, surface contamination,safe operating areas,
etc.Zenervoltage referencesandinputstage transistors
are preagedandlife expectancy extrapolated through
l/F noise change techniques during burn-in.
•Each power supply operated undermaximum stress con-
ditionsforaminimumof fifty hours priorto final inspec-
tion.
• Manufacturing proceduresand processesare equalto
or exceed thoseof MIL-Q-9858.
ELECTRICAL SPECIFICATIONS
Input:105-125volts,57-440Hz,100wattsnominal.
Output:0-60voltsDC,continuously adjustablewiththe fol-
lowing minimum output:
0-7V,0-5A 0-25V,0-2A 0-60V,0-0.5 A
0-15 V, 0-3 A 0-50 V, 0-1 A
LineRegulation:0.01%+1 millivoltforlinevariationsfrom
105-125volts.
LoadRegulation: 0.01 %+1millivoltforloadvariationsfrom
0-100%of ratedoutputcurrent, measuredatrear terminals
or atthejunctionofloadandsense leads.Without remote
sensing, regulationatfront panel terminalsis 0.01%+1.5
millivoltper ampereof output current(dueto bindingpost
voltagedrops).
Polarity:Eitherpositiveornegativeoutputterminalmaybe
operatedat ground potential.
Rippleand Noise:Lessthan1 millivolt peak-to-peakover
0-1MHzbandwithan inputlinefrequencyof60Hz.
Source Impedance:Lessthan0.005ohmatDC,0.1ohm
to 20 KHz, 1.0 ohmto 1 MHz.
Recovery Time:Lessthan50 microsecondsto returnto
withina 15millivoltbandofthe original voltagefora step
changein ratedloadof10%to100%(1microsecondrise
time).
Stability:Lessthan 0.02%+3 millivoltsper24hours after
warm-upat constant line,loadand ambient temperature.
Lessthan 0.01%+1 millivoltwith external remotepro-
gramming resistance.
Operating Temperature: 0-50°C atfull load. Storage:
-20°Cto +85°C.
Temperature Coefficient:Lessthan 0.02%per degreeC.
CurrentLimiting: Concentric switch/potentiometerpro-
vides continuous adjustmentof output currentintwo
ranges:0-500 milliamperes, 0-5 amperes.
Metering: Front panel "edgewise" meteranda selector
switch permits monitoring outputvoltageorcurrentwithan
accuracyof±2%offullscale.Currentrangechangesauto-
maticallywith current limiter range switch.
OutputTerminals:
Front Panel:Three insulated,5-way binding postsfor posi-
tive, negativeandground.
Rear Panel: Seven screw terminalsona molded barrier
blockfor positiveand negative output, chassis ground,re-
motevoltageprogrammingandremote sensing.
RemoteProgramming:Rear panel terminalsare provided
for external resistance programmingofthe output voltage.
The ratioofthe programming resistanceto output voltage
is 500ohmspervoltwitha ratio accuracyof±5%,and a
programminglinearityof 0.01 %ofmaximumoutputvoltage.
MECHANICAL SPECIFICATIONS
Dimensions: 8%" widex 4%" highx 11%" deep.
Weight: 15K
2
lbs.
Finish: Brushed anodized natural aluminum etched panel
with black nomenclature.Blue vinyl laminated steeldust
cover.Gold iridite bottom plate.
RackPanel Adapters: Brushed aluminum finished panel
5)4" x19"for mountinga single Model 6050:TypeRRG-3
(unit mountsincenterof panel),Type RRG-1 (unit mounts
leftorrightsideof panel).
Brushed aluminum finished panel 5%" x 19"for mounting
two Model6050units,sidebyside:TypeRRG-2.
Price: $12.50each.
PRICE: $195.00 F.O.B. Westbury,New York.
Pricessubjecttochangewithoutnotice
PairofpowersuppliesintypeRRG-2PanelAdapter
UnitshowniscalibratedpowersourceModel2005A
POWER DESIGNSINC.
1700 SHAMESDR.•WESTBURY, IM. Y . 11590
SIB EOgewood 3-BSOO TWX: 510-322-6561
POWER DESIGNS PACIFIC INC.
3381 MIRANDA AVE.• P A L O ALTO,CAL. 94306
41S-321-B111 TWX: 310-373-1881

UNIVERSALDCPOWERSOURCEMODEL6050
SECTION 1
GENERALDESCRIPTION
1-1.DESCRIPTION
The Model6050isa wide-range regulatedDCpower supplyutilizinga new regulator
technique*toprovidea broader spectrumof outputvoltagesandcurrentsthanis normally
availableina single unit.
The system employslinearcircuitryonlyandis RFI-free. Operationis completely
electronicwiththeregulator automatically seekingthatmodeofoperation which satisfies
the settingsofthepanelcontrols,theloaddemandandtheleveloftheACinputvoltage.If
theregulator cannot sustainits function,it signalsthis inabilitybya flashing panel indicator.
Thepower outputcapabilityofthe Model6050increaseswithACinputvoltages above
105volts. Useful regulated outputatreducedlevelsis availabledownto85volts.
1-2. ELECTRICAL SPECIFICATIONS
INPUT: 105-125volts, 57-440 Hz,100watts nominal.
OUTPUT:0-60 voltsDC, continuously adjustablewiththe following minimum output:
0-7V,0-5A;0-15V,0-3A;0-25V,0-2A,0-50V,0-1A;0-60V, 0-0.5 A
LINEREGULATION: 0.01% +1millivoltforlinevariationsfrom 105-125 volts.
LOADREGULATION: 0.01% +1millivoltforloadvariationsfrom 0-100%ofrated output
current, measuredatrear terminalsoratthe junctionofloadandsense leads. With-
outremote sensing, regulationatfront panelterminalsis 0.01% +1.5 millivoltsper
ampereofoutputcurrent(duetobindingpostvoltage drops).
POLARITY: Either positiveor negative outputterminalmay be operatedatground potential.
RIPPLEANDNOISE:Lessthan1millivoltpeak-to-peakover0-1MHzbandwithan input
linefrequencyof60Hz.
SOURCEIMPEDANCE:Less man 0.005 ohmatDC, 0.1 ohmto20KHz, 1.0 ohmto1MHz.
RECOVERY TIME:Lessthan50microsecondstoreturntowithina 15millivoltbandofthe
original voltagefora stepchangeinratedloadof10%to100%(1microsecondrise time).
STABILITY:Lessthan 0.02% +3millivoltsper24hours after warm-upatconstantline,load
and ambienttemperature.Lessthan 0.01% +1millivoltwithexternalremote program-
ming resistance.
*"UNIPLY" patents appliedfor.
9471-1

6050
OPERATINGTEMPERATURE:0-50°C at full load. Storage: -20°C to +85°C.
TEMPERATURE COEFFICIENT:Lessthan 0.02% per °C.
CURRENTLIMITING: Concentric switch/potentiometer provides continuousadjustment
of outputcurrentintworanges: 0-500 milliamperes, 0-5 amperes.
METERING: Frontpanel "edgewise"meteranda selector switchpermitmonitoringoutput
voltageorcurrentwithanaccuracyof±2%offull scale. Currentrangechangesauto-
maticallywithCURRENTLIMITER range switch.
OUTPUTTERMINALS: Front Panel- Three insulated, 5-way bindingpostsfor positive,
negativeandground.Rear Panel- Seven screw terminalsona moldedbarrier block
for positiveandnegative output, chassis ground, remote voltage programmingand
remote sensing.
REMOTEPROGRAMMING:Rear panelterminalsare providedfor external resistance
programmingofthe outputvoltage.Theratiooftheprogrammingresistance to
outputvoltageis500ohmspervoltwitha ratio accuracyof ±5% anda program-
ming linearityof 0.01% of maximum output voltage.
1-3.MECHANICAL SPECIFICATIONS
DIMENSIONS: 8-3/8"widex 4-3/4"highx 11-9/16" deep.
WEIGHT: 15-1/2lbs.
FINISH: Brushed natural aluminumetchedand anodized panelwithblack nomenclature.
Blue vinyl laminated steeldustcover.Goldiridite bottomplate.
9471-2

6050
SECTION 2
INSTALLATIONANDOPERATION
2-1. INSTALLATION
2.1.1 Laboratory Bench.The Model6050isa self-containedunitdesignedfor bench
use. Nopreliminary processingor unpackingisrequired.Thepower supplyisreadyfor
operationas shippedfromthefactory.A snap-out, bail-carrying handle assembly tilts
thefront panelfor viewingease.
2.1.2 Rack Mounting. Brushednatural aluminumfinish 5-1/4"x 19" adapters
are availablefor mountingoneortwounitsina standard 19" relayrack.Type RRG-3
mountsa singleunitinthecenterofthepanel.Type RRG-1 mountsa singleunitoneither
theleftor rightsideofthepanelfor installationof auxiliary instrumentation.Type RRG-2
mountstwo Model 6050's sidebysideona single adapter. Assemblyhardwarekitsare
providedwitheachadapter. If theplastic bumperfeetandhandle assembly interferewith
adjacent equipment, removethembydisassemblingthebottomplateofthe supply.
2-2. OPERATION
2.2.1 Operating Procedure
(a)BesuretheAC switchisoffandshortinglinksonrear terminal block
betweentheDC+andSENSE+,DC-andSENSE-,1and2 are tightened securely.
(b)SettheCURRENTLIMIT smallbarknobtothedesired output current
range.Notethatthefull scale readingofthe meterwillcorrespondtothe switch position.
Setthe largeCURRENTLIMITADJUSTcontrolfully clockwise.
(c)Setthe metermodeswitchtoVOLTS.
(d) ConnecttheAClinecordtoa sourceof 105-125volts, 57-440Hz.
(e)Ifremote sensing, remote programming, current limitingor series
operationisdesired,seerelevantparagraphsinthis section.
(f)TurnACswitchon.ACindicator should light.
(g)SetthelargeVOLTAGEcontroltothedesired valueofoutputvoltage.
TheFINEADJconcentric controlpermitsfine adjustmentoftheoutputvoltagewith a
resolutionof3 millivolts.
(h) ConnecttheDC+andDC-outputterminalonthefront panelandrear
panel to theload.Thepositiveor negative outputterminalmaybeoperatedatground poten-
tialbymeansofa jumperorleft floating,ifdesired.Iftheoutputterminalsareleft
floating,alargeACpotentialattheACline frequencymaybe introducedintotheload
9472-1

6050
throughcommonmodecouplingbetweentheACline,powersupply,loadandACline
operatedinstrumentsconnectedtotheload.Acapacitor(about1microfarad,100VDC,
paperorfilm dielectric)connectedfrom eitherDCoutputterminaltogroundterminal
willreducethisrippletoa satisfactory level.
2.2.2 OperationAboveRatings
Theoutputvoltageandcurrentratingsofthesupplyarelistedonthefront panel
abovethemeter.At AC inputlinevoltagesover105volts,thepowersupplymaybe
operatedatvoltageandcurrent levelsabovetheseratingswithoutsupplyoverloador
damage.Simplyincreasetheoutputvoltageoroutputloadcurrenttothedesiredvalue.
H thepowersupplyregulator systemcannot supporttheincreasedoutputduetopossible
linevoltageinadequacyorsupplylimitations,itwill signalthisinabilitybytheflashing
LIMITindicator.Thepowersupplymaybeoperatedindefinitelyintothisoverloadmode
(flashing indicator)withoutdamage.
Similarly,thesupplymaybeoperatedbelow105linevoltsatreducedoutputlevels.
Theflashing limit indicator willfunctionasa guidetoregulator capability.
TheCURRENTLIMITcontrolswillcontinuetofunctionevenwhenthepowersupply
is operatedbeyondtheratingsonthefrontpanel.Itmaystillbeusedtolimitmaximum
outputcurrentsbyadjustmentofthesecontrols.
Whenoperatingthesupplyaboveratings,thelimit indicatormaysuddenlystartto
flash.This signalsthattheACinputvoltagehasdroppedbelowa levelnecessarytosup-
porttheincreasedoutputpower.
NOTE:NeveroperatetheModel6050aboveitsmaximumratedACinputlinevoltageof
125volts for increasedpoweroutput.
2.2.3 RemoteSensing
The regulator systemoftheModel6050isanoperational amplifierwithinput
terminals (senseleadsS+and S-) maintainingtheregulatedoutputvoltageatthepointof
connectiontothepositiveandnegativepoweroutputterminalsof tiie supply(DC+andDC-).
Whentheseleadsareconnectedatthesupply (shortinglinksbetween Sense* andDC+,
Sense-andDC-on the rear terminalblock),thepowersupplyisconnectedfor localsens-
ing.Whenthe shortinglinksareremovedandthe senseleadsconnectedtothepower
outputleadsattheload,thesupplyisconnectedfor remote sensingandtheoutputvoltage
is compensatedforvoltagedropsduetotheDCresistanceofthepowerleads.
Remote sensingmayintroduce substantialphaseshiftathighfrequenciesbetween
the sense(input)terminalsofthe amplifierandthepower(output)terminalsduetothe
inductivereactanceofthe senseandloadleads.Thisconditionmaybecorrectedbythe
additionofa highfrequency,low impedance capacitor acrosstheoutputofthesupplyat
thejunctionoftheloadandsenseleads.Atantalumor electrolytic capacitorof suitable
voltageratingandlowimpedancecharacteristicsshouldbeused.Thecapacitanceshould
be largeenoughtocorrectforpoordynamicregulationduetothereactanceofthepower
outputleadsifthe load isswitchedor pulsed.
" « 2-2

G050
For remote sensing:
(a) Removethe shortinglinksfromtherear terminal blockDC+and Sense+
andDC-andSense- terminals.
(b) Connectthe DC+ andDC-terminalstothe load.Usetwisted#18AWG
or heavierwirefor minimum reactance.
(c) Connectthe Sense+andSense- leadstothepositiveandnegative power
leadsatthe load.Runthe sense leadsasa tightlytwisted, shieldedpair,ifpossible.Wire
sizeisnotimportantunlesslongrunsare involved (over twentyfeet). Connectthe shieldto
GROUNDterminalatthe supplyto minimize electrostatic noise pickup.
2.2.4 Serie s Oper ation
As manyasthree Model6050suppliesmaybeconnectedinseriestoprovideupto
180volts output,at 0.5 ampereorupto21voltsat5 amperes. ConnectthepositiveDC
outputterminalofone supplytothenegative outputterminalofthenext,in Hie same manner
as connectingbatteriesinseries.The groundterminalsonallunitsmaybeleftfloatingor
tiedtogetherandconnectedtoeitherthemostpositiveormostnegative output terminal.
CAUTION:THEVOLTAGEANDCURRENTLIMITCONTROLSOFALL SERIESCON-
NECTEDMODEL6050UNITSSHOULDBESETATTHESAME LEVELTO
AVOIDHEAVYREVERSECURRENTSFLOWINGINONEOFTHE SUPPLIES
WHENTHEREGULATORISINTHECURRENT LIMITEDMODEANDTHE
OUTPUTISREVERSEDBYTHEOTHER SERIES-CONNECTED SUPPLIES.
THEMODEL6050SHOULDNEVERBE OPERATEDINSERIESWITHANY
OF THELIMITINDICATOR LAMPSFLASHINGFORMORETHANA SHORT
PERIOD.
For optimum voltage regulation, disconnectthe shorting linksbetweenall Sense+
andDC+outputterminals exceptthoseatthemostpositive potential.Thenconnect jumper
wiresbetweeneach Sense+andSense-terminalonthenextmore positive power source.
Thevoltage dropsinthe leadsconnectingthepower sourceswillbe compensatedforbythe
regulator circuitsofthe individualunits.For remote sensing, follow these directions,
exceptconnect the mostpositiveandmost negative Sense+and Sense- leads acrossthe
load.
2.2.5 Parallel Operation
Parallel operationofthe Model6050isnot recommended.
2.2.6 Remote Voltage Programming
Theoutputvoltage can beprogrammed remotelybyanexternalfixedor variablere-
sistanceas follows:
(a)Turnoffthe power source.Setboth voltagecontrolstozero (extreme
counterclockwise position).
947 2-3

6050
(b) Removethe shortinglinkfrom betweentherear panel1and 2
terminals.
(c) Selecta programmingresistanceby multiplyingthe desired output
voltageby500(theprogrammingconstantis500ohmsper volt).Aconstantcurrentof
2milliampereswillflow throughthisresistance,andthewattage rating shouldbe chosen
to minimize driftdueto heating.
(d) Connecttheexternalprogrammingresistance betweenthe1and 2
terminals, usingtwisted, shieldedwire. Connectthe shieldtochassis ground(Gterminal)
to minimize output ripple.
(e)Turnonthepower source.
CAUTION:IFTHE REMOTEPROGRAMMINGCONNECTIONSARE OPENEDWHILETHE
SUPPLYISOPERATING,THEOUTPUTVOLTAGEWILLRISETOA LEVEL
AS HIGH Ab 70VOLTS,DEPENDINGUPONOUTPUTLOADCURRENT.IF
ASWITCHISUSEDTOSELECTRESISTORSFOR OUTPUTVOLTAGEPRO-
GRAMMING,USEONEWITHSHORTINGTYPECONTACTSTOAVOID
VOLTAGETRANSIENTSPRODUCEDBYOPENINGTHEREMOTEPROGRAM-
MINGTERMINALS.
2.2.7 Current Limiting
The maximum outputcurrentmaybelimitedtoanyvaluefromzeroto tkz maximum
outputcurrent rating ofthe supplyatanypreset outputvoltage level.
(a)Set t>.e CURRENTLIMITbarknobtothedesired outputcurrent ra-jo
0.5 A or5 A.
(b)Withloadconnectedtothe supply,turnthelarge concentricADJUST
knobfully clockwise.
(c)TurnADJUSTcontrol slowlycounterclockwise untilthe LIMITlamp
flashes,thenclockwise until flashingjust stops.Thecurrent limit operating threshold
is then approximately10%abovethe actualload current.
NOTE: If theloadcurrentisgreaterthanthatshownonthefront paneltablefora given
outputvoltage,the LIMITlampmay starttoflashwhen Hie AClinevoltage falls
to a level whichcannot supporttheincreased output.This signal indicatesAC
inputvoltage inadequacyratherthancurrent limiter circuit operation.
116 2-4

MODEL6050
TableshowingtypicalincreaseinusefuloutputwithincreasedAC
inputlinevoltage.
Output
Voltage
5
10
15
20
25
30
35
40
45
50
55
60
RatedOutput
Current(Amperes )
5
3.0
3.0
2.0
2.0
1.0
1.0
1.0
1.0
1.0
0.5
0.5
^Maximum OutputCurrent
(Amper es )
105 V A C
Line
5.5
3.8
3.8
2.5
2.25
1.45
1.3
1.3
1.2
1.2
1.2
1.1
115V A C
Line
5.5
4.2
3.8
2.8
2.4
2.0
1.4
1.3
1.3
1.3
1.3
1.25
125VA C
Line
5.5
5.2
3.8
3.6
2.5
2.4
1.75
1.45
1.4
1.4
1.4
1.4
**Increasein
Power
Output
10$
73$
26. 5 $
80$
25$
140$
75$
45$
40$
40$
180$
180$
*Withinratedpowersupplyregulationandripple specifications.
**At 125 VACinput.

6050
THEORYO FO P E R A T I O N
3-1. GENERAL
The Model6080isa voltage regulatedDCpower sourceofthe conventional series
dissipativetypeina unique configuration* whichprovides regulator efficienciesand operat-
ingfeaturesnotcommonly availableinthis regulator type.
Theconventional dissipative voltage regulator comprisesanunregulatedDC source,
avariable electronic resistance (power transistor)inserieswiththe unregulated sourceand
the load,an amplifier whichmeasuresthe differenceinvoltage betweena voltage reference
andsome fractionofthe output voltage obtained througha resistor divider acrosstheload
andamplifiesandappliesthis differencetothe series controltransistortovaryits resist-
anceinsucha directionas to maintainthe output voltage constantinthepresenceofload
currentandunregulated input voltage variations. Sincetheseries control elementisef-
fectivelyaresistance,itwilldissipate powerintheformof heat, depending uponthe voltage
acrosstheresistanceandthecurrent throughit.The output voltageoftheregulatorisad-
justedby varyingthe voltage reference,theresistor divider ratioor both.Ina wide output
range regulated supplythepower dissipatedinthe series elementincreaseswith increasing
unregulated source voltage, increasing outputcurrentandreduced output voltages.
The UNIPLY^ regulator utilizesa numberofunregulatedDCsources,anumberof
powertransistors,aseriesof diode"OR" gatesanda single control amplifier which selects
thatcombinationofunregulated sourceand series powertransistor whichbest satisfiesthe
output voltageandloadcurrent requirements, maintainingatthesametimethe minimum
available voltage difference betweenthe unregulated sourceandandthe load.By proper
selectionof unregulated sourceandseries powertransistor characteristics,itis possible
to designa regulatorwithessentially constant outputpower,i.e.asthe output voltageis
decreased,the available outputcurrentis increased.Thepowerlossesinthe regulator
remain approximately constant, independentof output voltageor current.
As a guideinunderstandingor maintenanceofthe Model 6050,this section provides
a step-by-step descriptionofeachcircuitandeach component function. Referencetothe
Schematic Diagraminthe Appendixis recommended.
3-2.ACPOWERSOURCE
AC inputpower(105to125VAC,57to440Hz)is applied througha 3-wire powercord
equippedwitha 3-blade NEMAplug.Thehotside (blackwire)oftheACflows throughfuseFl
(whichprotectsthe equipmentincaseof internal failure) throughtheAC switch SI, which turns
on thepower supply,totransformer(Tl)primary terminal115.The othersideoftheAC
inputpowergoestoterminal0oftransformerTl. Acrossterminals0 and115of transformer
Tl isaneonlamp, DSl,and series current limitingresistor,R35, whichindicatewhenthe
supplyhasbeenenergized. TransformerTl transformstheACinput voltageintothe required
secondary voltages.
*Trademarked UNIPLY® . Patents appliedfor.
1353-1

6050
3-3. VOLTAGE REFERENCESOURCE
Thetransformer secondary voltagefrom terminals9 to10is44VAC. Transformer
secondary terminal10goes toRFI filter capacitorC7andrectifier diode CR12.The other
sideofC7goesto secondary terminal9.TheothersideofCR12goestothe positive
terminaloffilter capacitorC5.Thenegativeterminalof C5 goesthroughcurrent limiting
resistor Rl to secondary terminal9.Thiscircuit producesanunregulated, filtered voltage
of 50VDCforthe reference circuitry.
Theunregulated filtered voltageof50voltsDCacrossC5is appliedtoa 20V pre-
regulator reference zener CR13, throughcurrent limitingresistorR2.
The pre-regulated voltage across CR13 is appliedtoa constantcurrent source compris-
ingtransistorQll, diode CR14, zener diode GR15 andresistors R4, R5andR6.
Thecurrentwillflowfromthe cathode(+)sideof CR13, through diode CR14 (which
compensatesforthebase-emitter voltage changeoftransistorQllwith temperature)
through zener diode CR15, whichisusedasa referencetoproduceaconstant voltage across
resistorR6 (6.3 V)throughbiascurrent resistorR5andbackto CRJ3 anode.The diode
CR18 willbediscussed laterinthe Current Limit Circuitry.
The voltage acrossR6, whichiscontrolledbytransistor Qll, producesa constant
currentthatflows through thecollector-emitteroftransistorQllandreference zener CR16.
TheresistorR4isusedto improvethe regulationofthe constantcurrent circuitby forming
abalancedbridge networkof R4S R5, R6
S
CR14 and CR15, whichfunctionstocorrect small
voltage variationsin CR13 duetoACline voltage changes.
3-4.WARNINGLIGHTCIRCUITRY
Transformer secondary terminals11and12supplythe voltageforthe flashing "limit"
lightcircuitry whichis comprisedofneonlight DS2, capacitor Cll, capacitor C10, diode
CR21, transistorQ12andresistorsR36andR37.
Whenthe power supplyisoperating withinits regulation limits,thewarninglightcir-
cuitryisessentially disconnectedfromthe regulator circuitrydueto insufficient voltagedrop
across warninglight sensingresistorR14to energize10volt zener, CR22.Inthismodeof
operation,theneonlampDS2isnotilluminated sinceQ12is saturatedby meansof current
flowing throughRl, emitter-to-baseof Q12, R36andrectifierCR21andthe voltage across
Q12istoolowto ignitetheneonlamp (requires90V minimum).The actionofthis circuit
in its flashingmodewill b® describedin"Warning LightCircuit Operation."
3-5. UNREGULATEDDCPOWERSOURCES
In the Model6050therearefourunregulated sourcesof power whichare electronically
connectedtotheloadbythree"OR" gates, CR1, CR2and CR3.
For referencepurposesinthis description, referto:
(a) Voltage across CI as Source1.
(b) Voltage across C2 as Source2.
(c) Voltage acrossC3as Source3,
(d) Voltage acrossC4as Source4.
1353-2

6050
Source 1 reoeive8 its voltagebycurrent flowingfrom transformer secondary terminal
4 to C1+, through Cl and rectifier CR4 toterminal5 for one half of t h e " AC cycle,andfrom
secondary terminal4 to Cl+» through Cl andrectifier CR5 toterminal3fortheother half
of lite ACcycle.
Source2receivesits voltagebycurrentflowingfrom transformer secondary terminal
5 throughCR6 to C2+, throughC2andrectifier CBS to terminal 3 forhalftheAC cyeie5 and
from secondary terminal 3 through CR? to C2+, through C2 andrectifier CR4 to terminal 5
for otherhalfoftheAC cycle.
Source 3 receivesits voltagebymeansofcurrent flowingfrom transformer secondary
terminal7 to C3+, throughC3andrectifier CR8 to terminal8 forhalftheACcycle,andfrom
secondaryterminal1to C3+, throughC3andrectifier CE9 toterminal6forthe othssr halfof
theAC cycle.
Source4receivesits voltagebymeansofcurrent flowingfrom transformer secondary
terminal8 through CR10 toC4+, throughC4andrectifier CR9 toterminal6forhalftheAC
cycle,andfrom secondary terminal6through CR11 to C4+* through04andrectifier CR8 to
terminal 8fortheotherhalfoftheACcycle.
Source1and Source2bothderive their voltagesfrom transformer secondary terminal
3 to 5,whichis19VAC.
Source1DCvoltageis9 to 12.
Source2DCvoltageis 19.2 to 25.0.
Source3 and Source4bothderive their voltagesfrom transformer secondary terminals
6to8 (58VAC)
Source3 DCvoltageis 30.6 to 40,0.
Source4 DCvoltageis62.2 to 80.5.
Thecapacitor C8
S
whichis connected across transformer terminals3 and5,andthe
capacitor C9
f
whichis connected across transformer terminals6 and 8
S
reducethe effect
of highfrequency transients generatedbyrectifier diodes CR4 throughCE11.
The negative outputsof Sources1, 2
$
3 and4 areallcommontoone anotherandare
connected directlytothe "DC-"outputofthepower supply.
3-6. SERIESREGULATORTRANSISTORS
Thepositive outputof Source1 (Cl+) is connectedtotheDC+outputofthe supply through
"OR" gateCE1and CR25(connected inparallel), Source 1regulatingtransistors Ql and Q2,
outputcurrent sensingresistor R30 andeither R42, R43(0.5 ampere maximum outputcur-
rent)orS4(5.0 ampere maximum outputcurrent), determinedbyS4switch setting.
Thepositive outputof Source 2 (C2+)is connectedtotheDC+outputofthe supply
through"OR"gate CR2, Source2regulatingtransistor Q3, Source2current sensing resistor
R28, Qland Q2 base-emitter junctions, R30andeither R42
s
R43orS4.
Thepositive outputof Source3 (C3+)is connectedtotheDC+outputofthe supply through
"OR" gate CR3
S
Source3 regulatingtransistor Q4
5
Source3current sensingresistor R26, Q3
base-emitter junctions Source2current sensingresistor R28, QlandQ2base-emitter junc-
tions, R30andeither R42, R43 (0.5 ampere maximum outputcurrent)orS4(5.0 ampere maxi-
mum outputcurrent), determined by S4switch setting.
1353-3

OUDU
Thepositive outputof Scarce4 (C4+) is connectedtothe DC+ outputofthe supply through
me Source4 regulating transistorQ5, Source4current sensing resistor R24,* Q4 base-emitter
junction, Source3 current sensingresistor R26»Q3base-emitter junction, Source2 current
sensingresistor R28, Ql and Q2base--emitter junctions, R30 and either R42, R43 orS4.
3-7. VOLTAGEREGULATORAMPLIFIER.CIRCUITRY
Theresistor R29 acrossQl, Q2 base-emitters providescurrentbiasforQ3.
Theresistor R27 across QSbase-emitter providescurrentbiasforQ4series regulator.
TheresistorR25across Q4- base-emitter providescurrentbiasfor Q5.
TheresistorE23across Q5 base-emitter providescurrentbiasfor Q6 driver.
The resistorR22across Q6 base-emitter provides current biasforQ? amplifier.
Theresistor R21 acrossQ7 base-emitter pro?idescurrentbiasfor Q9 amplifier.
TheresistorR17across Q9 base-emitter providescurrentbiasforQ10input transistor.
Thebaseof Source4 regulating transistorQ5is connectedtothe emitter ofdriver Q6.
Thebaseofdriver Q6 is connected to the emitterofcurrent amplifier Q7.
ThecollectorsofQ6and Q7 are commonandare connectedtoC5+throughcurrent limiting
resistor R15.
ThebaseofQ7is connectedto fee collectorof amplifierQ9 through warninglight sensing
resistor E14. CapacitorCIS is connected acroasR14 inordertoeliminateparasitic oscilla-
tions. The RC network CI?andR19 are connectedfromQ7basetoQl,Q2emittersalsoto
eliminate parasitic oscillations.TheRCnetwork C14 andR13are connected acrossQ9base-
to-collector to stabilizethe power supply amplifier circuitry throughoutitsoperating frequency
range.Theemitterof Q9 is connected to the positivesideofthe pre-regulator reference
CR13(+20V) through decouplingresistorR3.ThisresistorR3andcapacitor C12 form an RC
networkwhichfiltersout zener diode noise (generated by CR13) fromthe amplifier circuitry.
Thebaseof Q9 is connected tothecollectorofQ10througha current limitingresistorR12.
TheemitterofQ10is connectedto -the junctionof SENSE* output terminal^ CR16 voltage
reference anode, CR18 anode, R4„ R5and C21.
ThebaseofQ10is connected throughcurrent limitingresistor Rll tothe junctionof
E8 and CRI7 anode.The othersideof resistor R8is connectedto.thepositivesideofthe
6,3V reference voltage (CE16 cathode}. The resistor provides a Mascurrent through diode
CR17 whichisusedtocompensatethechangeinbase-emitter voltageof Q10with temperature.
ThecathodeofCR17isthe voltage sensingpointofthepower supplyregulator.Atthis point,
theoutputvoltageofthepower supplyis comparedtothereference voltage (CR16) by means
of a divider networkconsistingofa dividercurrent adjusting potentiometers, R9
§
dividercur-
rent determining resistor, R10
5
remote programmingterminalsI and2 (normally shorted),
coarse outputvoltage controlresistorRS1Aandfine output voltage control resistor R31B.
Thedividercurrentwill flow from CR16 cathode throughresistors R9, RIO, R31A, R31B to
SENSE-outputterminal.Thecurrent flowing throughR8willcontrolthebasebiasonQ10
andwillalsoflow through divider resistors R31Aand R31B.
Capacitor C13
?
whichis connected across outputvoltage adjusting resistorsR31Aand
R31B, decreasesthe amplitudeofthe rippleandnoiseatthe input to voltage amplifier transis-
tor Q10
s
byincreasingthe AC-to-DC feedback ratio.
135 3-4

ThepositivesideofcapacitorC0 ie connectedto fee DC+output terminal andthe
negative sideofcapacitorC6is connected tothe DC- output terminal.Thecapacitorsup-
pliestransient energy requiredbytheload that is beyondthefrequency bandwidthorre-
sponsetimeofthe voltage regulator circuitry,
Whenthe outputvoltageofthepower supplyisbeingcontrolled internally by potentio-
meters R31A and R31B, theremote programming terminals1and2 are shorted togetherby
a jumper.
Whenthe output voltageis beingcontrolledbyexternalresistors,the internal poten-
tiometersE31Aand R31B aresettozero ohms andtheexternal programmingresistorre-
places the jumper betweenremote programmingterminals1and2.
Whenthe output voltageis sensed directlyatthe DC+ and BC~ outputterminalsofthe
supply, ajumperis connected between SENSE+ and DC-f- andbetween SENSE-andDC-.
Whenthe output voltageis sensed remotely, theSENSE+ terminalisconnectedto the
desired locationoftheleadthatgoesfromtheDC+terminaltothe load,andthe SENSE-
terminalis connectedtothe desired locationoftheleadthatgoesfromtheDC™terminalto
theload. Regulationis maintained acrossthesepoints (junctionofloadand sense leads).
3-8. CURRENTLIMITCIRCUITRY
Thecurrent limit circuitry consistsofa tworange adjustable current sensing circuit:
0to 0.5A and0 to 5.0A for Source1,afixed current sensingcircuitfor Source2,a fixed
current sensingcircuitfor Source 3 and a fixed current sensingcircuitfor Source4.
Thesefour separate current sensingcircuitsareall commonly coupled to a current
limiter circuit whichcontrolsthebiasingof the driver transistor Q7, which,in turn,
controlsthe outputcurrentofthe supply.
• Thetworange adjustable current sensing circuitconsistsofcurrent sensing resistor
R30, 0.5A-5. OA range switch S4, current sensingresistor R42, 0.5A rangeset potentiometer
R43, 5.0A rangesetpotentiometer B33, resistor R34, variable output"current limit" poten-
tiometer R32, diode CR19 (usedtocompensatethechangeinbase-emitter voltageofQ16
with temperature), current sensingtransistor Q16, resistor R7, whichdeterminesthecur-
rentthrough CR19, anddiode CR18, whichprovidescollector voltageforQ16.
TheDCoutputcurrentwillflowfrom Ql, Q2 emitterstoR30current sensing resistor,
throughR30 to thejunctionofR42andS4.WhenS4isclosed,theoutputcurrentwillflow
throughR30andS4.ThusthecurrentismonitoredonlybyR30.WhenS4is open,theDC
outputcurrentwillflow through R30, R42 and R43. ThepotentiometerR43is adjustedso
feat the maximumDCoutputcurrent range beingmonitoredis10%oftherangewhenthe
currentflows throughS4.Fromthe junction ofS4and R43, thecurrentwillflow to theDC+
output terminals.
The Source2 current sensingcircuit consistsoftransistor Q13, current sensing
resistorR28andresistorR46whichprotects Q13 base againstcurrent transients.
The Source3 current sensing circuitconsistsoftransistor Q14, current sensing
resistor R2d andresistorR45whichprotects transistor Q14from current transients.
135 3-5

8050
Tto Sotura* 4 current ionising circuit consistsof transistor Q15, current sensing
resistorR24 and resistorR44 whichprotectstransistor QlS from current transients.
Thecollectorsof Source2current sensingtransistor Q13
3
Source3 current sensing
transistor Q14, Source4current sensingtransistorQ15andthe adjustable range current
sensingtransistorQ16areall coupledtothebaseofcurrent limittransistorQ17throughthe
common, collector ^oad resistorsR16and R20, ResistorR16isconnected across Q17 emitter
to base. CapacitorC16stabilizesthecurrent limitcircuitry throughoutits operatingfre-
quencyrange.ThecollectorofQl?is connectedtothebaseof Q7 current amplifier. Q13,
Q14, QlS and Q16 are normallycutoff.
If anyofthefour current limitcircuitsare energizeddue to a current exceedingthe
pre-set level, transistorQ17willbe activatedbytheflowofcollector current through R16
and R20 whieis, inturn,willcontrolthebasecurrentof Q7, whichwilllimitthe outputcur-
rentofthe supply to thepredeterminedset level.
3-9. METERCIRCUITRY
Theoutput voltageor currentis monitoredbya single meter Ml connectedintothe
desiredmodeofoperationby switchS3.
Whenoperatingasa voltmeter, the switchS3isinthe "VOLTS" position.The DC
J-
of the supplyis connectedto M1+ through switchS3.TheDC-ofthe supplyis connectedtoMi-
through voltagecalibration adjustment potentiometer R47, resistor R38, switch S3
S
current
calibration adjustment potentiometer EM andresistorR40.
Whenoperatingasanammeter,the switch S3isinthe "AMPS"position.The junc-
tionofR30andR29is connectedtoM1+ through, switchS3.The DC+ ofthe supplyiscon-
nectedtoMl- through switch S3
S
current calibration adjustment potentiometerR39and
resistorR40.
4-0. OPERATIONOFTHE UNIPLY® REGULATORSYSTEM
Whenthepower supplyis operatedatanoutputvoltagesuch fiat Source1 supplies
the output power, the series regulatingtransistorsareQlandQ2operatinginparallel.The
Source2 series regulating transistorQ3isnowfunctioningasa driverfor transistorsQl
andQ2.The Source3 series regulating transistorQ4isnowfunctioningasa driverfor
transistorQ3.The Source4 series regulatingtransistorQ5isnowfunctioningasa driver
for transistorQ4.
Therefore, whenthe output voltageissuchthat Source1suppliesthe output power,
transistors Q3* Q4, Q5, Q6and Q7 all functionas drivers.
If Source1is deliveringthe outputpowertotheloadandthe output voltageis increased
or theACline voltagedecreases,suchthatthe voltageof Source1is insufficientto supply
regulated powerto the load,the Source1"OR"gate diodeCR1willstopconducting,thusdis-
connectingitfromtheload whileatthesametimetheloadcurrentis automatically transfer-
redto Source2throughQlandQ2base-emitter junctions. Source2current sensing resistor
R28and Source2 series regulatingtransistorQ3.
If Source2 is deliveringthe outputpowertotheloadandtheoutput voltageis increased
or theACline voltagedecreasessuchthatthe voltageof Source2is insufficientto supply
135 3-6

6050
y@gulat@d powerto the load,the Source 2 "OR"gate diode CR2 willstopconducting,thus
disconnecting Source2fromtheload whileatthesametimetheload current is automatically
transferredtoSource3 throughQ3base-emitter junction, Source3 current sensing resistor
R26 andSource3 series regulatingtransistorQ4.
If Source3 is deliveringthe outputpowertotheloadandthe outputvoltageis increased
or theACline voltage decreasedsuchthatthevoltageofSource3 is insufficientto supply
regulated power to theload,the Source3
f
'OR" gate diodeCR3willstopconducting current
from Source3,thus disconnectingitfromtheloadwhileatthesametimetheload current
is automatically transferredto Source4 throughQ4base-emitter junction, Source4 current
sensingresistorR24andSource4 series regulatingtransistorQ5.
Thefollowingare minimum outputratingsthatcanbe deliveredbyeach source:
Source1:0to7 VDCat0 to 5 ADC
Source2:7to15VDCat0 to3 ADC
Source3:15to25 YBC at0 to2ADC
Source4:25to50VDCat0 to1ADC,50 to 60VDCat0 to 0.5 ADC
Theseratingsare basedona minim.um line voltageof105VAC.Whentheline voltage
is increasedto125VAC,the outputratingswillincreaseto:
Source1:0to 9 VDCat0 to5ADC
Source2:9to20VDCat0 to3 ADC
Source3:20to34VDCat0 to2ADC
Source4:34 to 68*VDCat0 to1 ADCS *68 to *80 VDCat0 to 0.5 ADC
It canbe seen,fromthetwosetsof outputratings,thatthechangeoverfromone source
to anotherwillbe dependentnotonlyonoutput voltage,butalsoon available inputACline
voltage.Thepower supplywillautomatically selectthe sourcethatwilldeliverthe output
ratings required.
4-1. WARNINGLIGHT
If anoutputrequirementissuchthatitcannotbehandledbyanyofthefour sources,or
if the supplyisina current limit mode,awarninglightwill flash about2-5timesper second
untiltheloadrequirementis withinthepower supplycapability,orthe supplyisnolongerin
acurrent limit mode.
For example: Warning LightFlashing Warning LightOff
35 VDCat2 A at105to125VAC line 34VDCat2 A at125VACline
55 VDCat1A at105VACline55VDCat1A at114VACline
18 VDCat3 A at105VACline18VDCat3 A at116VACline
12 VDCat4 A at105to125VACline12VDCat3 A at105 to 125VACline
4-2. VOLTAGEREGULATION
In describingtheoperationofthe voltageregulatoritis assumedthattheload resistance
hasdecreasedin value.
*Whenexternally programmed.
1353-7

6050
4.8.1 0to7 VDCOutput
When the resistanceoftheloadis decreased, the outputvoltagewill tend to decrease.
Thedecreaseinoutputvoltageis sensedby transistorQ10 asanincreaseinbase current.
TheincreaseinQ10base current increasesitscollector current* whichflows through
transistorQ9 base. Therefore, Q9basecurrent andcollector current increase.Thein-
creased Q9 collector current increasesthedriver transistor Q7 base current, which
increases driver transistor Q6 basecurrent, which increasesthedriver transistor Q5
(Source4 series regulatingtransistor)base current, whichincreasesthedriver transistor
Q4 (Source3 series regulating transistor) basecurrent, whichincreasesthedriver transis-
torQ3(Source2 series regulating transistor)base current^ whichincreasesthe Source 1
series regulatingtransistors Ql andQ2basecurrents, whichincreasesthe availableDC
outputloadcurrent untilthe output voltageis withintheload regulation specificationof
the power supply.
4.2.2 50 VDCOutput
Theoperationat50VDCoutputisthesameasthe operationat0 to 7 VDCoutputex-
cept that-the driver transistor Q5 inthe0 to7 VDCoutputnowisthe Source4 series regu-
latingtransistor.TheincreaseinQ5base current increasesits collector current, which
flows through R24
y
Q4 base-emitter junction, R26
s
Q3 base-emitter junction, R28, Ql,
Q2 base-emitter junctionstotheDC+outputterminalofthe supplyandtotheloaduntilthe
output voltageis withintheregulation specification ofthepower supply.When Q5 is acting
as theseries regulator, fee
n
ORf' gatesCR1, CR2 andCR3have automatically disconnected
Sources1,2and3 respectivelyfromthe load.
4-3. ADJUSTABLECURRENTLIMITOPERATION
If theloadcurrent increases above a predetermined levelsetbythe panel CURRENT
LIMITcontrol R32, the voltagedropacrossR30(if operatinginthe0 to5Arange),orR30,
R42andR43(if operating inthe0 to 0.5 A range), will forwardbiasthe base-emitterof
transistor Q16. When transistor Q16isforward-biased,itscollector currentwillflow
and-forwardbiasthecurrent limittransistor Q17. Theresultantcollector currentof Q17
will flow fromthepositivesideof zener CR18(+20V) through decouplingresistor R3
S
emitter-to-collector of transistor Q9, warning light sensingresistor R14 andthroughthe
collector-to-emitterof Q17. When Q17 collector current has increased toa predetermined
value,the increased voltage drops acrossR3 andR14 willreducethe collector-to-emitter
voltageofQ9tozero. When thisoccurs, fee voltage regulatingtransistorsQ9and Q10 will
havenoeffectonthebiascurrentofdriverQ7.Whenthisoccurs, the biascurrentof
driver Q7 is entirely dependentonthecollector currentof Q17, whichinturnis entirely
dependentontheloadcurrent flowing'throughthecurrent sensingresistors which forward
biasedtransistorQ16.The power supply isnowoperatingina constantor fixed output
current mode.
4-4. CURRENTLIMITINGOFSOURCES2, 3OR 4
If theload current from sources 2, 3or4 is increasedtothe maximum predetermined
limitofthe source,the voltagedrop across one ofthe sourcecurrent sensing resistors
R28, R26orR24willforwardMasthe associated current sensingtransistorsQ13, Q14
or Q15. Example:
1. Loadcurrentof Souiae 2greaterthan3 ADC: VoltagedropacrossR28will
forwardbiasQ13.
1353-8

6050
2. Load current of Source3 greaterthan2 ADC: Voltagedrop across R26 will forward
MasQ14.
3. Loadcurrentof Source4greaterthan1 ADC: Voltagedrop across K24 will forward
bias Q15.
Sincethecollectorsof Q13, Q14 andQ15 are connectedtothecollectorof Q16, the
current limit operationofthese transistors i 3 thesameasthatwhencollector current
was flowing throughtransistor Q16.
4-5, WARNINGLIGHTOPERATION
Wheneverthecurrent limit transistor Q17is activatedduetoeither excessive output
currentorthe inabilityoftheAClinevoltageto support a desired outputratinginexcess
of fee published ratings* the voltagedrop across warning light sensingresistor R14 will
energizea 10Vzener diode CR22. WhenCR22 conducts, thebaseofQ12is reverse-biased,
cuttingofits collector current.Thecurrentflowing throughR37then flows through Cll
untilthe voltagedropacrossCll reachesthe striking voltageofthe LIMIT neon lamp.
The lamp ignitesandbeginstodischarge C1L ThepulsatingDCcurrent flowingfrom
transformer terminal 12totheparallel combinationofLIMITneonlamp DS2 and capacitor
Cll throughcharging resistorR3?andhalf-wave diodeCR21totransformer terminal11
is insufficient to sustaintheoperating voltageoftheneonlampDS2.NeonlampDS2will
extinguishandthecapacitor will again charge untilthe ignition voltageofneonlamp DB2
is againreached.Thecircuit componentsare selectedsothattheLIMITneonlampDS2
willflash2to5 timesper second.Thecapacitor CIO acrossthebase-emitter junction
of Q12 integratesthepulsatingDCcurrent flowingfrom transformer terminal 12through
Q12base-emitter junction, resistor R36, and diode C.H21 totransformer terminal11.
Thiscapacitor functionsto prevent pulsatingDCpotentialsfrom beingcoupledintothe
amplifier through, the internal capacitanceof zener CR22.
135

6050
SECTION 4
MAINTENANCE
4-1. GENERAL
Undernormal conditions, no specialor preventive maintenance is required.Aperi-
odic checkis recommendedat annual intervals. Recalibration in accordance withthepro-
cedures outlinedin thissection shouldbe mad*"- when necessary.
Should servicing berequired,it should not be attemptedexceptbya technician ex-
perienced to the maintenanceof regulated power suppliesor solid state linear circuitry.
Adequate instrumentation with required accuracy shouldbe available.
The UMPLY regulator systemdoesnot involvecomplex circuitry, butis sufficiently
uniquethatrepairofthe supply shouldnotbe attempted until Section 3 "Theoryof Operation*
1
is read thoroughly.Thissectionofthe manual is detailedandprovidesacomplete descrip-
tionofeachcircuitandcomponentfunctionaswellasananalysisoftheregulator systemIn
every operating mode.
Reference to thevoltages listedonthe schematic diagramwillbeusefulinisolating a
defect. However* it shouldbe notedthat in any BC closedloopsystema single defectmay
drasticallychangemanycircuit voltages. Normalvoltagesmayvary10%from those shown
on the schematic diagram.,
CAUTION:IX)NOTOPERATETHEPOWER SUPPLY WITH INTERNALLEADSOR
COMPONENTSDISCONNECTEDANDA LOADONTHE OUTPUT.AREGU-
LATORSYSTEMRUNAWAYMAYOCCUR AND, INTHE PRESENCEOFAN
OUTPUT LOAD, DAMAGEORDESTROYINTERNALCOMPONENTS. HIGH
GAIN DCCOUPLEDAMPLIFIERSARE SUSCEPTIBLETOCHAINREACTION
BURNOUTSUNDERTHESECONDITIONS.ALWAYSREMOVEEXTERNAL
LOADSBEFORESERVICING.
4-2. TESTEQUIPMENT
The following equipmentis recommendedfor calibratingor servicingthe Model 6050:
A. OSCILLOSCOPE:Asuitableunitfor measuring rippleand noise. It shouldhave
avertical sensitivityofatleast500 pv/centimeter, abandwidthtoI MHzanda vertical
sensitivityof5 mv/eentimeter to30MHz.
B. DIGITAL VOLTMETER:Afive digit DVM with, one millivolt stepsinthelast place
andanaccuracyof 0.1% or better.
C. DCAMMETER:A1%instrumentwife ranges to 10 amperes* Adigital voltmeter
withprecision shuntsmayalsobe utilized.
D. VOLTAGEREFERENCESOURCE:AcalibratedDCsourcewithgood stability,ad-
justableto 60 volts. Anuncalibrated, regulated sourcemaybeusedinconjunctionwith
a DVM, Another Model6050maybeso utilized.
1364-1

6050
E. MULTIMETER: AgeneralpurposeAC/DCmulti-range meter withan input impedance
of 20,000 fl/volt andohmmeterranges to100 megS.
F. VARIABLE AUTOTRAN8FORMER: An adjustableunitwitha capacityof3 amperesfor
varyingthe AC input voltageto fee supply.
G. OUTPUT LOAD? Aresistorbankorpreferably an adjustable constantcurrent electronic
loadwitha rating of 0-6A and 0-100V. ifMs load canbe electronicallyswitched onandoff
at a repetitionrateofabout60Hzandhave a rise timein theorderofa mteroeecond* itwill
be usefulfor transient responseandrecoverytime measurements.
4-3.CHE CKIN GA N DR E C A L I B R A T I N GT H ES U P P L Y
Refertoschematicandpictorialdiagramsfor circuit function andcomponentor adjust-
menttrimmer potentiometer location,
4.3.1 CHASSISISOLATION: Using themultimeteronitshighestresistance range,
check fee resistancebetweentheDCoutput terminals andtheACinputpinsofthelinecord
plugto chassis, Theresistanceshouldbeover100 megS.
4.3.2 Removethe vinylclad top dustcoverandthebottomplate.
4.3.3 PANELMETERZEROADJUSTMENT:Mechanicallyset file pointer to zero
while fee unitisina horizontal position^ observingthe Instrument fromapositionperpendi-
cular to the
nO"
calibrationline to avoid parallax,. Thezeroadjustmentisa flush plastic
screwat fee rearof the meter.
4.3.4PANELMETERCALIBRATION:
1. Set fee following:
(a)AC line voltageto115volts.
(b) CURRENTLIMIT range switch to EA positionandCURRENTLIMIT
potentiometer to its maximum clockwiseposition*
(e) VOLTAGEcontrolpotentiometer to 80 VDC using fee external digital
voltmeter.Thiscontrol should provideanoutputof61-62voltsinits maximum clockwise
positionwiththeFINEVOLTAGEcontrolin its maximumecwposition. H 60voltscannot
be obtainedortheoutputvoltageisinexcessof82volts, readjust R9 trimmer potentiometer.
(Thenormal rang© oftheFINEVOLTAGE ADJ potentiometeris0.6V £0, IV.)
2. Witt meterfunctionswitchintheVOLTS position* checkmeterfor calibration
at 60 volts* positioning jonr eyeperpendicular to fee meter scaleat60 to avoidparallax.
3. Applya 5Aload tothefront paneloutputterminals, usingtheaccurate external
currentmeterfor calibration.WithmeterfunctionswitchintheAMPS positions checkpanel
meterfor 5.0A reading. Adjust R39 trimmer potentiometer If necessary.
136 4-2