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Fluke 5725A instruction manual 11A Range Functional Description

Models: 5725A

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5725A

Instruction Manual

The 5700A/5725A system uses the following method for ac amplitude control:

1.An rms thermal sensor alternately measures two signals: an unknown but adjustable ac signal, and a known calibrated dc signal.

2.The output of the thermal sensor is measured by the adc, allowing settling time for the sensor each time its input is changed. The ac signal is adjusted until the thermal sensor output is the same for both signals. Thus, the dc voltage at the output of the thermal sensor is not important, but differences in the dc voltage when the sensor input is switched between the ac variable and dc reference are important.

To ensure safe, reliable operation, the High Voltage Amplifier is turned on in the following sequence:

1.The 5700A Oscillator is set to the 22V range and its output is channeled to the 5725A High Voltage Amplifier on line BOOST IN.

2.Then the output of the High Voltage Amplifier is connected to the appropriate high voltage step-up transformer (one of three).

11A Range Functional Description

4-4.

The 5725A Current Amplifier is a transconductance amplifier that has a compliance voltage of 3.0V rms for the ac current function and 4.0V for the dc current function. The transconductance amplifier has a gain of -5 (e.g., 1V in gives -5A out). Either the 5700A 2V range for dc operation, or the Oscillator for ac operation, drives the transconductance amplifier. Input voltage to the transconductance amplifier comes in on BOOST IN (for ac current) or B-FEEDBACK (for dc current) and enters the High Voltage Sense assembly. From there it is routed to the error amplifier on the Current assembly whenever the 5725A is in the current function. The B-FEEDBACK line returns the current calibration amplifier output to OSC SENSE HI during ac current operation.

The following assemblies are active in the 5725A current function:

∙In the 5700A: CPU, DAC, Oscillator, Switch Matrix, Motherboard, Rear Panel assemblies. (Plus the Oscillator assembly in the ac current function.)

∙In the 5725A: CPU, Current, High Voltage Sense, Digital, and Power Supply.

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Fluke 5725A instruction manual 11A Range Functional Description

Contents

Instruction Manual 5725AAmplifier Page Table of Contents 5725A Theory of OperationCalibration and Verification 5725A Instruction ManualTable List of TablesTitle 5725A Figure List of FiguresTitle viii 5725AInstruction Manual Declaration of the Manufacturer or Importer Interference InformationBescheinigung des Herstellers/Importeurs Page OPERATOR SAFETY SUMMARY HIGH VOLTAGELETHAL VOLTAGE Terms in this ManualSymbols Marked on Equipment Power SourceUse the Proper Power Cord Use the Proper FuseSERVICING SAFETY SUMMANY FOR QUALIFIED SERVICE PERSONNEL ONLYDo Not Service Alone Use Care When Servicing With Power OnFIRST AID FOR ELECTRIC SHOCK Free the Victim From the Live ConductorGet Help Never Accept Ordinary and General Tests for DeathIntroduction and Specifications Chapter5725A Instruction ManualIntroduction Where to Go From Here How to Use the Manuals 5700A Operator Manual5700A Operator Reference Guide 5700A Remote Programming Reference GuideSpecifications 5700A Service ManualIntroduction and Specifications SpecificationsDC Voltage Range Resolution Absolute UncertaintyInstruction Manual 5725AAC Voltage Specifications Introduction and SpecificationsAC Voltage continued 5725A Instruction ManualAC Voltage continued Voltage RangeIntroduction and Specifications SpecificationsTwo-WireAdder active compensation Note Lead Resistance Nominal ValueTwo-WireComp Four-WireFour-Wire 5725A Instruction ManualSpecifications Introduction and SpecificationsDC Current Instruction Manual 5725AAC Current Specifications Introduction and SpecificationsAC Current continued Resolution Resolution5725A Instruction ManualIntroduction and Specifications SpecificationsGeneral Specifications Temperature performance: Operating: 0C to 50C5725A Instruction ManualInstallation Service InformationPlacement and Rack Mounting Connecting to the 5700A Calibrator5725A Instruction ManualInstallation Unpacking and InspectionIntroduction 5725A Instruction ManualTYPE VOLTAGE/CURRENTService Information Placement and Rack MountingCooling Considerations Service InformationConnecting to the 5700A Calibrator Figure 2-2.Correct Way to Dress Interface CableSelecting Line Voltage Selecting Line VoltageAccessing the Fuse wCautionConnecting to Line Power Connecting to Line Power5725A Instruction ManualOperating Notes Chapter5725A Instruction ManualIntroduction Operating NotesFront Panel Features Figure 3-1.Front Panel FeaturesPOWER 5725AA B C D E F G H Rear Panel FeaturesTable 3-1.Front Panel Features 5725A STANDBY IndicatorRear Panel Features Figure 3-2.Rear Panel Features5725A Instruction ManualA B C D E F G H I Table 3-2.Rear Panel FeaturesCALIBRATION Switch 5700A CALIBRATOR ConnectorTurning on the 5725A Amplifier Warm Up5725A Operating Functions and Modes StandbyVoltage Standby Current Standby 5725A Operating Functions and ModesVoltage Operate 3-103-11 Current OperateConditions That Activate the 5725A Conditions That Activate the 5725A 3-12Theory of Operation ChapterHigh Voltage Sense Assembly A6 High Voltage Amplifier A3High Voltage Heat Sink Assemblies High Voltage Amplifier FeedbackOverall Functional Description Introduction5725A Figure 4-1.5725A Overall Block DiagramInstruction Manual 1100V AC Range Functional Description 11A Range Functional Description Operation in the 11A DC Range Operation in the 11A AC RangeVoltage and Current Standby Modes Voltage StandbyHow the 5700A and 5725A Communicate 4-10Description of the Out-GuardLines 5725A Side 4-11Description of the In-GuardLines 4-12Functional Summaries by Assembly 4-13Interconnect Assembly A1 Detailed Circuit Description4-14 4-15Power Supply Assembly A4 4-16High Voltage Supply Section 4-17ASSEMBLY REF DESSwitching Section 4-18Current-LimitSection 4-19System Supply Section 4-20Digital Assembly A5 Fan Supply Section4-21 4-22Figure 4-2.Digital Assembly Block Diagram Theory of OperationDetailed Circuit Description aq19f.epsEEROM 4-26Data Latch 4-27Power Up and Reset Circuitry Watchdog TimerCurrent Amplifier Assembly A2 Break-DetectCircuitryInstruction Manual 5725Aaq20f.eps Error Amplifier Section 4-35Output Stage Section 4-36Monitor Section 4-37Control and Switching Section Power Supply Section4-38 4-39High Voltage Amplifier A3 4-40Input Amplifier 4-41Detailed Circuit Description Theory of Operationaq22f.eps Integrator 4-42Window Comparator 4-43Transconductance and Cascode Stage 4-45Midstage 4-46Autobias Current Source 4-49Autobias Sense Circuit 4-50Signal Transformers High Voltage Amplifier Feedback4-51 4-52High Voltage Sense Assembly A6 4-54Detailed Circuit Description Theory of Operationaq21f.eps Sense Amplifier Section 4-55±3.2V during calibration Analog Monitor Section 4-56SIGNAL STANDBY VOLTAGE LIMITS1Analog Input Switching Section Serial Interface/Guard Crossing Section4-57 4-58Control Section 4-59AC Line Voltage Selection Section 4-605725A Instruction ManualCalibration and Verification Chapter5725A Instruction ManualIntroduction Where to Find Further InformationCalibration and Verification 5725A Instruction ManualMaintenance Chapter5725A Instruction ManualReplacing the Fuse IntroductionCleaning the Air Filter Cleaning PCA’s General CleaningGeneral Cleaning Access Procedures Figure 6-3.Assembly Location DiagramA. TOP VIEW B. BOTTOM VIEWInitial Access Procedure wWarningHIGH VOLTAGE Accessing the Power Supply Assembly A4 Accessing the Digital Assembly A5WHEN REINSTALLING DIGITAL ASSEMBLY Figure 6-5.Accessing the Digital Assembly5725A Instruction ManualAccessing the Current Amplifier Assembly A2 6-106-11 Accessing the High Voltage Amplifier A3Figure 6-6.Correct Way to Dress Cables Accessing the High Voltage Sense Assembly A6 6-12Accessing the High Voltage Output Transistors Accessing the Interconnect Assembly A16-13 6-14Enabling Front or Rear Binding Posts 6-159.Reinstall the top cover Troubleshooting Chapter5725A Instruction ManualSelf Diagnostics 5725A Fault CodesIntroduction Table 7-1.5725A Fault Codes FAULT5725A Instruction Manual MESSAGESelf Diagnostics Table 7-1.5725A Fault Codes contFAULT MESSAGEManual Tests for Fault Isolation Manual Tests for Fault Isolation Table 7-2.Analog Monitor FaultsFAULT NO MESSAGEReduced-VoltageTroubleshooting Mode Problem 3: Fault When Entering Voltage OperateProblem 4: Fault When Entering Current Standby Problem 5 Fault When Entering Current Operate7-10 Testing the Power Supply By ItselfTesting the Power Supply By Itself 5725A Instruction ManualList of Replaceable Parts Chapter5725A Instruction ManualHow to Obtain Parts Manual Status InformationNewer Instruments IntroductionService Centers Assembly NameTable 8-1.Final Assembly 5725ATable 8-1.Final Assembly cont List of Replaceable Parts5725A Figure 8-1.Final Assemblyaq24f.tif List of Replaceable Parts Figure 8-1.Final Assembly contaq25f.tif Figure 8-1.Final Assembly cont 5725AInstruction Manual aq26f.tifList of Replaceable Parts Figure 8-1.Final Assembly contaq27f.tif Figure 8-1.Final Assembly cont 5725AInstruction Manual aq28f.tifList of Replaceable Parts Figure 8-1.Final Assembly contaq29f.tif Figure 8-1.Final Assembly cont 5725AInstruction Manual aq30f.tifList of Replaceable Parts Figure 8-1.Final Assembly contaq31f.tif 5725A Table 8-2.A1 Interconnect PCAList of Replaceable Parts 5725A-1611Figure 8-2.A1 Interconnect PCA aq36f.epsInstruction Manual 5725ATable 8-3.A2 Current Amplifier PCA List of Replaceable Parts Table 8-3.A2 Current Amplifier PCA cont5725A Instruction ManualTable 8-3.A2 Current Amplifier PCA cont Reference Description DesignatorList of Replaceable Parts 5725A-1650Figure 8-3.A2 Current Amplifier PCA aq37f.epsInstruction Manual 5725ATable 8-4.A3 High Voltage Amplifier PCA Table 8-4.A3 High Voltage Amplifier PCA cont List of Replaceable PartsDesignator 5725A Instruction ManualTable 8-4.A3 High Voltage Amplifier PCA cont R640,R642List of Replaceable Parts 5725A-1661Figure 8-4.A3 High Voltage Amplifier PCA aq38f.eps5725A Table 8-5.A4 Power Supply PCAInstruction Manual Table 8-5.A4 Power Supply PCA cont List of Replaceable PartsTable 8-5.A4 Power Supply PCA cont 5725AInstruction Manual R351 R355 R361,R362Figure 8-5.A4 Power Supply PCA List of Replaceable Parts5725A-1631 aq39f.epsInstruction Manual 5725ATable 8-6.A5 Digital PCA List of Replaceable Parts 5725A-1650Figure 8-6.A5 Digital PCA aq40f.eps5725A Table 8-7.A6 High Voltage Sense PCAList of Replaceable Parts Table 8-7.A6 High Voltage Sense PCA cont5725A Instruction ManualTable 8-7.A6 High Voltage Sense PCA cont R154 R155 R156,R158,R168 R173 R162 R171 R172,R175List of Replaceable Parts 5725A-1601Figure 8-7.A6 High Voltage Sense PCA aq41f.eps5725A Table 8-8.A12 Transformer Enclosure AssemblyInstruction Manual List of Replaceable Parts Figure 8-8.A12 Transformer Enclosure Assemblyaq32f.tif 5725A aq33f.tifList of Replaceable Parts aq34f.tifInstruction Manual 5725Aaq35f.tif List of Replaceable Parts Table 8-9.A30 Inductor PCA5725A-1603 Figure 8-9.A30 Inductor PCA5725A Schematic Diagrams Chapter5725A Instruction ManualSchematic Diagrams 5725A-1611Figure 9-1.A1 Interconnect PCA aq48f.epsInstruction Manual 5725AFigure 9-1.A1 Interconnect PCA cont Schematic Diagrams Figure 9-1.A1 Interconnect PCA cont5725A Instruction ManualFigure 9-2.A2 Current Amplifier PCA 5725A-1650Schematic Diagrams Figure 9-2.A2 Current Amplifier PCA contInstruction Manual 5725AFigure 9-2.A2 Current Amplifier PCA cont Schematic Diagrams Figure 9-2.A2 Current Amplifier PCA cont5725A Instruction ManualFigure 9-3.A3 High Voltage Amplifier PCA 5725A-1661Schematic Diagrams Figure 9-3.A3 High Voltage Amplifier PCA contInstruction Manual 5725AFigure 9-3.A3 High Voltage Amplifier PCA cont Figure 9-4.A4 Power Supply PCA Schematic Diagramsaq59f.eps Figure 9-4.A4 Power Supply PCA cont 5725ASchematic Diagrams Figure 9-4.A4 Power Supply PCA contAT PINS 12 AND 13 OF U507 5725AInstruction Manual TYPICAL COMMUNICATIONS ACTIVITYSchematic Diagrams Figure 9-5.A5 Digital PCA cont5725A STANDBYVOLTAGE STANDBY CURRENT STANDBYSchematic Diagrams Figure 9-6.A6 High Voltage Sense PCA contInstruction Manual 5725AFigure 9-6.A6 High Voltage Sense PCA cont Schematic Diagrams Figure 9-6.A6 High Voltage Sense PCA contInstruction Manual 5725AFigure 9-6.A6 High Voltage Sense PCA cont Figure 9-7.A12 Transformer Enclosure Assembly Schematic Diagramsaq45f.eps 5725A Instruction ManualIndex 5725A Page 5725A Instruction ManualManual Supplement Change #1 rear