Agilent Technologies AGILENT MODELS 6023A and 6028A service manual Initial Setup, 1KVA

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Table 2-1. Test Equipment Required (continued)

TYPE

REQUIRED CHARACTERISTICS

USE

RECOMMENDED MODEL

Switch

SPST, 30A @ 20V

P

 

DC Power Supply

Voltage range: 0-60Vdc

T,P

Agilent 6296A

 

Current range: 0-3Adc

 

 

 

 

 

 

Variable Voltage

Range greater than -13% to +6% of

P,A

 

Transformer

nominal input AC voltage

 

 

(autotransformer)

1KVA

 

 

 

 

 

 

P = performance

testing A = calibration adjustments

T = troubleshooting

*Resistors may be substituted for test where an electronic load is not available.

**Less accurate, and less expensive, current-monitor resistors can be used, but the accuracy to which current programming and current meter reading can be checked must be reduced accordingly.

Initial Setup

Maintenance described herein is performed with power supplied to the instrument, and protective covers removed. Such maintenance should be performed only by service trained

personnel who are aware of the hazards involved (for example, fire and electrical shock). Turn off ac power when making or removing connections to the power supply. Where maintenance can be performed without power applied, the power should be

removed.

a.Unplug the line cable and remove the top cover by removing three screws; the rear handle screw and the two top-rear corner screws. Do not remove the front handle screw as the retaining nut will fall into the unit.

b.Slide the cover to the rear.

c.Plug a control board test connector A2P3 onto the A2J3 card-edge fingers.

d.Turn OVERVOLTAGE ADJUST control A3R59 fully clockwise.

e.Disconnect all loads from output terminals.

f.Connect power supply for local sensing, and ensure that MODE switches are set as shown below.

g.Reconnect the line cable and turn on ac power.

h.Allow unit to warm up for 30 minutes.

i.When attaching the DVM, the minus lead of the DVM should be connected to the first node listed, and the plus lead should be connected to the second node listed.

j.At the beginning of each calibration procedure, the power supply should be in its power-off state, with no external circuitry connected except as instructed.

k.The POWER LIMIT adjustment (A2R25) must be adjusted at least coarsely before many of the calibration procedures can be performed. If you have no reason to suspect that the Power Limit circuit is out of adjustment, and you do not intend to recalibrate it, do not disturb its setting. Otherwise, center A2R25 before you begin to calibrate the power supply.

l.To disable the power supply, short INHIBIT line A2J3 pin 8 to COMMON A2J3 pin 4.

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Contents Autoranging Certification Safety Summary Printing History Safety Symbol DefinitionsTable of Contents Replaceable Parts Scope TroubleshootingCircuit Diagrams Safety ConsiderationsItem Description Manual RevisionsOperation Verification Tests Calibration ProcedureIntroduction Test Equipment RequiredTest Equipment Required Type Required Characteristics USE Recommended Model1KVA Initial SetupMON Calibration ProcedureIout VoutCR7 Performance TestsMeasurement Techniques Constant Voltage CV Tests Current-Monitoring Resistor SetupBasic Test Setup RMS Measurement Test Setup, CV Pard Test Peak-To-Peak Measurement Test Setup, CV Pard Test KHz Noise, CV Peak-to-Peak Pard 6023A 6028ALoad Transient Recovery Waveform Constant Current CC Tests CC Pard Test Setup Initial Troubleshooting Procedures TroubleshootingWAVEFORM/CONDITIONS Source Control Board Test Connector, A2J7PIN no Signal Name VdcElectrostatic Protection Repair and ReplacementA2 Control Board Removal A1 Main Board Removal A4 Power Mesh Board RemovalOverall Troubleshooting Procedure A3 Front-Panel Board RemovalMeasurement Using the TablesSetup NodeMain Troubleshooting Setup Main Troubleshooting SetupModified Mains Cord Set For Troubleshooting Front-Panel Troubleshooting Troubleshooting No-Output FailuresBoard PWM-ON PWM-OFF Defective Check Functional CircuitsA2J7-26 A2J7-25 Node + Measurement Source Troubleshooting Bias SuppliesSymptoms Defective Circuit Check Components Symptoms Defective Check Functional Circuits BoardNode + N0DE Node +Measurement Source Setup Measurement Power Section BlocksTroubleshooting AC-Turn-on Circuits Setup Measurement SourcePower Limit Troubleshooting PWM & ClockRelay Enable PWM-OFF Troubleshooting DC-To-DC Converter+ OUT PWM-ONTroubleshooting CC Circuit Troubleshooting CV CircuitA4U4OUT Troubleshooting Down ProgrammerTroubleshooting OVP Circuit Waveforms SET Voltage Vdc Node + Page Block Diagram Overview Autoranging PowerBlock Diagram Simplified Schematic Simplified Schematic Down Programmer DC-to-DC ConverterConstant-Voltage CV Circuit Pfet Control Signals Timing DiagramControl-Voltage Comparator Power-Limit ComparatorConstant-Current CC Circuit Overvoltage Protection OVP CircuitAC-Surge Dropout Detector Initial-Ramp CircuitPulse-Width Modulator PWM Bias Voltage DetectorDisplay Circuits Second-Delay CircuitPage Reference Designators Replaceable PartsDescription Abbreviations Ordering InformationCR3 Electrical PartsCR1 CR2Mechanical Parts XA2P1XA2P2 Control Board Assembly CR3 Page Page Page VR5 VR3VR4 DS5 CR5DS1 VR2 IC A/D Cmos 3-1/2 DGTVR1 Pfet NPN SIChassis Electrical TS1A4 Board Mechanical Parts A1TB1A2 Board Mechanical Parts A3 Board Mechanical PartsOption 240 240V Operation Option 220 220V OperationComponent Location and Circuit Diagrams Schematic Diagram Notes Pin locations for other semi-conductors are shown below Top View, Top Covers Removed Main Board A1 Component Location Control Board A2 Component Location Front-Panel Board A3 Component Location Power Mesh Board A4 Component Location Page Page Option 002 Hardware SpecificationsGeneral Information Status Indicators Table A-1. Specifications, Option Remote ProgrammingInput Compliance Voltage ± Current Programming Enable Output Impedance 10.2 k ohm ± 5% Temperature CoefficientOn State logic low Remote Trip and Remote Reset TimingPower-on Preset Maximum Output Voltage logic high +Pard Typical Table A-1. Specifications, Option Pulse TimingBias Supplies DC Output Ratings 25C ± Short Circuit Output CurrentConnector Assembly Procedure InstallationOperation Figure A-1. Mating Connector AssemblyLocal/Remote Programming Resistance Voltage or Current Figure A-4. Calculating Value of Series Dropping Resistor Remote Resistance ProgrammingFigure A-5. Remote Resistance Programming Remote Monitoring Remote Control Status IndicatorsOvervoltage Remote ResetFigure A-8. Remote Control Power-On PresetMultiple Supply System Shutdown AC Dropout Buffer CircuitBias Supplies MaintenanceTroubleshooting Current Programming Troubleshooting Resistance and Voltage ProgrammingFigure A-11. Troubleshooting Current Programming of CV Mode Figure A-13. Troubleshooting Status Indicators Page REF. Desig Model no Description Table A-3. Replacement Parts100 101 VR9Definitions Indicator and Qualifier SymbolsOLD Symbol NEW Symbol Logic Symbols and Definitions 102Schematic Diagram Notes 103 Schematic NotesFigure A-15. Option 002 Board, Component Location 104 Schematic NotesFigure A-16. Option 002 Board, Schematic Diagram 105 Page 107 Model 6023AModel 6028A 108 From