Agilent Technologies AGILENT MODELS 6023A and 6028A service manual Remote Resistance Programming

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Figure A-4. Calculating Value of Series Dropping Resistor

Remote Resistance Programming

Check switches A1 and A2 on the rear panel, they must be in their correct positions for CV and CC resistance/voltage programming (See Figure A-2). A resistance variable from 0 to 4K ohms can be used to program the output voltage or current from 0 to full scale. To program the output voltage, connect the variable resistance between J3-25 (CV RES/VOLT PROG.) and J3-22 (E COM.). To program the output current, connect the variable resistance from J3-24 (CC RES/VOLT PROG.) to J3-22 (E COM.).

If the programming lines become open circuited during resistance programming (user’s system becomes disconnected from J3), the power supply's output will tend to rise above rating. The supply will not be damaged if this occurs, but the user's load may be damaged. To protect the load, be sure that the overvoltage trip point is properly adjusted. The unit includes clamp circuits to prevent it from supplying more than about 120% of rated output voltage or current when the remote programming voltage is greater than 5Vdc or remote programming resistance is greater than 4K ohm. Do not intentionally operate the unit above 100% rated output. Limit your programming voltage to 5Vdc and programming resistance to 4K ohm to assure reliable operation.

Remote Voltage Programming (Figure A-6).Check switches Al and A2 on the rear panel, they must be in the correct positions for CV and CC resistance/ voltage programming (See Figure A-2). A voltage source variable from 0 to 5 volts, can be used to program the output voltage or current from 0 to full scale. The load on the programming source is less than 1mA. To program voltage, the voltage source should be connected from J3-25 (CV RES & VOLT PROG) to J3-22 (E COM). To program current, the voltage source should be connected from J3-24 (CC RES & VOLT PROG) to J3-22 (E. COMMON). If the programming lines become open circuited (user's system becomes disconnected from J3) during voltage programming, the Programming Protection circuit will reduce the power supply output to zero.

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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 VoutPerformance Tests Measurement TechniquesCR7 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 FailuresPWM-ON PWM-OFF Defective Check Functional Circuits A2J7-26 A2J7-25Board Node + Measurement Source Troubleshooting Bias SuppliesSymptoms Defective Circuit Check Components Symptoms Defective Check Functional Circuits BoardNode + Measurement SourceNode + N0DE Setup Measurement Power Section BlocksTroubleshooting AC-Turn-on Circuits Setup Measurement SourceTroubleshooting PWM & Clock Relay EnablePower Limit PWM-OFF Troubleshooting DC-To-DC Converter+ OUT PWM-ONTroubleshooting CC Circuit Troubleshooting CV CircuitTroubleshooting Down Programmer Troubleshooting OVP CircuitA4U4OUT 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 CR2XA2P1 XA2P2Mechanical Parts Control Board Assembly CR3 Page Page Page VR3 VR4VR5 CR5 DS1DS5 IC A/D Cmos 3-1/2 DGT VR1VR2 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 Specifications General InformationOption 002 Hardware 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 Model 6023A Model 6028A107 108 From