Agilent Technologies AGILENT MODELS 6023A and 6028A service manual VR3, VR4, VR5

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Table 5-4. A2 Control Board Parts List (continued)

Ref. Desig.	Agilent Model	Agilent Part Number	Description
R139	All	0757-0442	Resistor 10KΩ 1% 1/8W
R140	All	0698-3160	Resistor 31.6KΩ 1% 1/8W
R141	All	0683-1025	Resistor 1KΩ 5% 1/4W
R142	All	0683-2225	Resistor 2.2KΩ 5% 1/4W
R143	All	0683-1045	Resistor 100KΩ 5% 1/4W
R144	All	0683-4725	Resistor 4.7KΩ 5% 1/4W
R145	All	0683-4715	Resistor 470Ω 5% 1/4W
R146,147	All	0683-1125	Resistor l.1KΩ 5% 1/4W
R148	All	0683-3925	Resistor 3.9KΩ 5% 1/4W
R149	All	1810-0365	Network sip 2.2KΩ X5
R150,151	All	0683-1815	Resistor 180Ω 5% 1/4W
R152	All	0683-1025	Resistor 1KΩ 5% 1/4W
R153	6028A	0683-1035	Resistor 10KΩ 5% 1/4W
R155,158	6023A	8159-0005	Resistor 0Ω
R155	6028A	0683-1005	Resistor 10Ω 5% 1/4W
R156-158	6028A	0683-1005	Resistor 10Ω 5% 1/4W
S1	All	3101-2097	Switch 6-lA slide
U1	All	1826-0493	IC op amp lo-bias hi-impedance
U2	All	1826-0346	IC op amp dual general purpose
U3	All	1826-0161	IC op amp quad general purpose
U4	All	1826-0527	IC voltage regulator 1.2/37V
U5	All	1826-0544	IC voltage reference 2.5V
U6	All	1826-0428	IC voltage regulator 1/40V
U7,8	All	1826-0493	IC op amp lo-bias hi-impedance
U9	All	1826-0544	IC voltage reference 2.5V
U10	All	1826-0161	IC op amp quad general purpose
U11	All	1820-1209	IC flip flop D-type
U12	All	1826-0393	IC voltage regulator 1.2/37V
U13	All	1820-1112	IC flip flop D-type
U14	All	1820-0138	IC comparator quad
U15	All	1820-1437	IC multivibrator monostable dual
U16	All	1820-0065	IC comparator precision
U17	All	1820-1246	IC gate quad AND
U18	All	1820-0935	IC counter binary CMOS
U19	All	1820-1205	IC gate dual AND
U20	All	1826-0138	IC comparator quad
U21	All	1826-0065	IC comparator precision
U22	All	1820-2096	IC counter binary dual
VR1,2	All	1902-0018	Diode zener 11.7V 5%
VR3	All	1902-0777	Diode zener 6.2V 5%
VR4	All	1902-3110	Diode zener 5.9V 2%
VR5	All	1902-0575	Diode zener 6.5V 2%
W1-3	All	7175-0057	Jumper wire 22 AWG
Y1	All	0960-0586	Resonator 320kHz
		MECHANICAL PARTS
	6028A	5060-2942	Heatsink (Q2, U15, 16)
	6028A	1200-0181	Insulator
	6028A	1200-0485	Socket (S1)
	6028A	0360-2195	Terminal block, 6-position
	6028A	1531-0309	Clevis, tapped

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Contents Autoranging Certification Safety Summary Safety Symbol Definitions Printing HistoryTable of Contents Replaceable Parts Safety Considerations TroubleshootingCircuit Diagrams ScopeManual Revisions Item DescriptionTest Equipment Required Calibration ProcedureIntroduction Operation Verification TestsType Required Characteristics USE Recommended Model Test Equipment RequiredInitial Setup 1KVACalibration Procedure MONVout IoutCR7 Performance TestsMeasurement Techniques Current-Monitoring Resistor Setup Constant Voltage CV TestsBasic Test Setup RMS Measurement Test Setup, CV Pard Test Peak-To-Peak Measurement Test Setup, CV Pard Test 6023A 6028A KHz Noise, CV Peak-to-Peak PardLoad Transient Recovery Waveform Constant Current CC Tests CC Pard Test Setup Troubleshooting Initial Troubleshooting ProceduresVdc Control Board Test Connector, A2J7PIN no Signal Name WAVEFORM/CONDITIONS SourceRepair and Replacement Electrostatic ProtectionA2 Control Board Removal A3 Front-Panel Board Removal A4 Power Mesh Board RemovalOverall Troubleshooting Procedure A1 Main Board RemovalNode Using the TablesSetup MeasurementMain Troubleshooting Setup Main Troubleshooting SetupModified Mains Cord Set For Troubleshooting Troubleshooting No-Output Failures Front-Panel TroubleshootingBoard PWM-ON PWM-OFF Defective Check Functional CircuitsA2J7-26 A2J7-25 Symptoms Defective Check Functional Circuits Board Troubleshooting Bias SuppliesSymptoms Defective Circuit Check Components Node + Measurement SourceNode + N0DE Node +Measurement Source Setup Measurement Source Power Section BlocksTroubleshooting AC-Turn-on Circuits Setup MeasurementPower Limit Troubleshooting PWM & ClockRelay Enable PWM-ON Troubleshooting DC-To-DC Converter+ OUT PWM-OFFTroubleshooting CV Circuit Troubleshooting CC CircuitA4U4OUT Troubleshooting Down ProgrammerTroubleshooting OVP Circuit Waveforms SET Voltage Vdc Node + Page Autoranging Power Block Diagram OverviewBlock Diagram Simplified Schematic Simplified Schematic DC-to-DC Converter Down ProgrammerPfet Control Signals Timing Diagram Constant-Voltage CV CircuitOvervoltage Protection OVP Circuit Power-Limit ComparatorConstant-Current CC Circuit Control-Voltage ComparatorBias Voltage Detector Initial-Ramp CircuitPulse-Width Modulator PWM AC-Surge Dropout DetectorSecond-Delay Circuit Display CircuitsPage Replaceable Parts Reference DesignatorsOrdering Information Description AbbreviationsCR2 Electrical PartsCR1 CR3Mechanical Parts XA2P1XA2P2 Control Board Assembly CR3 Page Page Page VR5 VR3VR4 DS5 CR5DS1 VR2 IC A/D Cmos 3-1/2 DGTVR1 NPN SI PfetTS1 Chassis ElectricalA3 Board Mechanical Parts A1TB1A2 Board Mechanical Parts A4 Board Mechanical PartsOption 220 220V Operation Option 240 240V 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 Output Impedance 10.2 k ohm ± 5% Temperature Coefficient Table A-1. Specifications, Option Remote ProgrammingInput Compliance Voltage ± Current Programming Enable Status IndicatorsMaximum Output Voltage logic high + Remote Trip and Remote Reset TimingPower-on Preset On State logic lowShort Circuit Output Current Table A-1. Specifications, Option Pulse TimingBias Supplies DC Output Ratings 25C ± Pard TypicalInstallation Connector Assembly ProcedureFigure A-1. Mating Connector Assembly OperationLocal/Remote Programming Resistance Voltage or Current Remote Resistance Programming Figure A-4. Calculating Value of Series Dropping ResistorFigure A-5. Remote Resistance Programming Remote Monitoring Status Indicators Remote ControlRemote Reset OvervoltagePower-On Preset Figure A-8. Remote ControlAC Dropout Buffer Circuit Multiple Supply System ShutdownMaintenance Bias SuppliesTroubleshooting Resistance and Voltage Programming Troubleshooting Current ProgrammingFigure A-11. Troubleshooting Current Programming of CV Mode Figure A-13. Troubleshooting Status Indicators Page Table A-3. Replacement Parts REF. Desig Model no Description100 VR9 101Logic Symbols and Definitions 102 Indicator and Qualifier SymbolsOLD Symbol NEW Symbol DefinitionsSchematic Notes Schematic Diagram Notes 103Schematic Notes Figure A-15. Option 002 Board, Component Location 104Figure A-16. Option 002 Board, Schematic Diagram 105 Page 107 Model 6023AModel 6028A From 108