Agilent Technologies 66332A, 6634B, 6633B, 6632B service manual Principles of Operation

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Principles of Operation - 4

The output is programmed off.

An overvoltage condition is detected (OV_Detect* signal is received).

The line voltage falls below 90 volts (approximately).

Current readback is provided by three separate circuits. The previously discussed high range current signal (Imon_H) returns the high range current measurement. When the unit is operating in the low current readback mode, a separate low range current shunt and amplifier provides low-current readback via the Imon_L signal. The Range_Select signal drives shunt clamps Q304 and Q305, which clamp the voltage across RmLo to approximately 1.8 V. A third current readback circuit is available on the Agilent 66332A unit. It consists of a high bandwidth current amplifier that returns dynamic current measurements from the output filter capacitor via the Imon_P signal. Note that the Imon_H and the Imon_P signal are combined to return the actual output current measurement.

An overvoltage detect circuit compares the output voltage to the programmed overvoltage setting. When the output exceeds the programmed setting, the OV_Detect* signal goes low, which informs the logic array that an OV condition has occurred. The crowbar control circuit is enabled when the OV_SCR* signal is received. When an overvoltage condition occurs, the SCR control circuit generates the OV signal, which causes the following actions to occur:

1.The SCR fires, shorting the supply's output.

2.The microprocessor circuits are notified of the OV condition (OV_Detect* is low) in order to program the output off, turn off the gain stage bias, and update the status of the unit.

3.When a output protection clear command is executed, the microprocessor circuits resets the OV circuits, turns on the gain stage bias, and programs the output to its previous level.

The fan driver control circuit provides the DC voltage to operate the cooling fan. The Fan_Prog signal from the secondary interface circuit varies this voltage according to the ambient and heatsink temperature as well as the output voltage and current of the supply.

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Contents Agilent Part No Microfiche No October Certification Warranty InformationBefore Applying Power Safety SummarySymbol Description Safety Symbol DefinitionsItem Description Printing HistoryInstrument Identification Table of Contents Disassembly Procedures Initialization ROM UpgradeIntroduction General Schematic Notes Backdating Post-repair CalibrationPage Organization Safety ConsiderationsRelated Documents ChapterElectrostatic Discharge RevisionsManual Revisions Firmware RevisionsIntroduction Type Specifications Recommended ModelTest Equipment Required Built-in Self TestsMeasurement Techniques Test SetupPerformance Tests Operation Verification TestsElectronic Load Current-Monitoring ResistorConstant Voltage CV Tests CV SetupVoltage Programming and Readback Accuracy CV Load EffectCV Noise Pard CV Source EffectCC Setup Transient Recovery TimeConstant Current CC Tests Current Programming and Readback AccuracyCC Load and Line Regulation Current Sink -CC OperationLow Range Current Readback Accuracy CC Source Effect CC Load EffectCC Noise Pard Performance Test Equipment FormPerformance Test Record Forms − 4 mV + 4 mV Vout − 12 mV Model Agilent 6634B Report No Date Test Description MinimumVout − 42 mV Iout + 0.29 mATroubleshooting Flow Charts Overall TroubleshootingTest Equipment Required for Troubleshooting Type Purpose Recommended ModelSheet 1. Main Flowchart Sheet 2. Main Flowchart Sheet 3. Main Flowchart Sheet 4. OV at Turn-On Sheet 5. OV at Turn-On Sheet 6. FS Indicated but Fuse OK Sheet 7. No Output Voltage Sheet 8. No Output Voltage Sheet 9 No Output Voltage Sheet 10. No Current Limit Sheet 11. Unit Does Not OV Sheet 12. High Output Voltage Power-on Self-test Failures Specific Troubleshooting ProceduresSelf-Test Error Codes/Messages Error Code Description Probable CauseBias and Rail Voltages CV/CC Status Annunciators TroubleshootingBias and Reference Voltages Bias Test Point Common MeasurementVoltage Measurements at J307 A2 Interface to A1 Main board J307 Voltage MeasurementsManual Fan Speed Control Disabling Protection FeaturesPost-repair Calibration Inhibit Calibration SwitchCalibration Password Upgrade Procedure ROM UpgradeInitialization Identifying the FirmwareList of Required Tools Disassembly ProceduresRemote sense leads before attempting disassembly Front Panel Assembly, Removal and Replacement Cover, Removal and ReplacementA2 Interface Board, Removal and Replacement A3 Front Panel Board, Removal and Replacement S1 Line Switch, Removal and ReplacementT1 Power Transformer, Removal and Replacement A1 Main Control BoardTransformer Wiring Line Voltage WiringConnector Signal Description Interface SignalsPower Supply Interface signals A2 Interface Circuits A3 Front Panel CircuitsPrimary Interface Secondary InterfaceA2/A3 Block Diagram A1 Main Board Circuits Power CircuitsA1 Block Diagram Control Circuits Principles of Operation Page Designator Model PartNumber Qty Description Chassis, ElectricalDesignator Model Part Number Qty Description Chassis, MechanicalMechanical Parts ldentification A1 Control Board PC Board Assembly Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Replaceable Parts Relay Option #760 Binding Post Option #020A5 AC input/RFI Board Model-dependent Components General Schematic NotesDiagrams A1 Board Component Locations R434 825 R500 175 325 R435 R505 A1 Board Component Locations A4 and A6 Board Component Locations A1 Board schematic sheet A1 Board schematic sheet A1 Board schematic sheet A6 Relay Option Board schematic Index Index Manual Updates
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6632B, 6633B, 66332A, 6634B specifications

Agilent Technologies, a leader in electronic test and measurement solutions, offers a range of power supplies designed to meet various application needs. Notable models include the 6632B, 6634B, 66332A, 6633B, and 6612C. Each of these units provides unique features and technologies that cater to researchers, engineers, and technicians in the industry.

The Agilent 6632B is a single-output DC power supply that delivers up to 30V and 3A. It is known for its excellent load regulation and low noise, making it ideal for sensitive electronic testing. The model includes built-in voltage and current measurement capabilities, allowing users to monitor output conditions in real time. The 6632B is commonly used in laboratory environments, educational institutions, and manufacturing lines.

Moving to the 6634B, this model offers dual-output capabilities with a maximum output of 30V and 6A. This versatility enables simultaneous powering of two different devices or circuit sections. It also features parallel and series operation options, allowing users to create a custom power supply configuration for specific applications. With a programmable interface, the 6634B simplifies test automation, ensuring efficiency in extensive testing scenarios.

The Agilent 66332A stands out with its precision and high performance. This power supply provides three outputs—two programmable and one fixed—yielding flexible power configurations. Its intuitive user interface allows easy adjustment of voltage and current settings. The device is equipped with extensive protection features to safeguard both the power supply and the connected load against faults. It is an excellent choice for complex testing setups that require reliable power.

The 6633B model offers a high-performance power supply with dual outputs, similar to the 6634B but with enhanced specifications. It can provide up to 40V and 2A per channel, delivering precision for demanding applications. This model is particularly suited for industries focused on high-reliability applications, such as telecommunications and aerospace.

Lastly, the Agilent 6612C is a compact and lightweight power supply providing single-output up to 60V and 2A. This model is designed for simplicity and ease of use, making it an excellent choice for portable applications. The 6612C’s unique characteristics include a compact design and user-friendly controls, which facilitate operation in field settings.

In summary, Agilent Technologies’ power supply models—6632B, 6634B, 66332A, 6633B, and 6612C—offer an array of features that cater to a wide range of testing and research needs, ensuring reliable power delivery in various contexts.
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