Kenwood PS 50 Service Manual

The Kenwood PS 50 is a professional-grade power supply unit designed for laboratory and industrial applications. This service manual provides comprehensive technical information including specifications, circuit diagrams, troubleshooting procedures, calibration instructions, and maintenance guidelines for qualified service technicians.

1. Technical Specifications 2. Safety Precautions 3. Installation Guidelines 4. Operating Instructions 5. Circuit Description 6. Block Diagrams 7. Calibration Procedures 8. Maintenance Schedule 9. Parts List 10. Troubleshooting Guide

Technical Specifications

The Kenwood PS 50 power supply features precision voltage regulation, current limiting, and multiple output modes for versatile laboratory applications.

ParameterSpecification
Output Voltage Range0-50V DC adjustable
Output Current Range0-5A DC adjustable
Line Regulation≤ 0.01% + 2mV
Load Regulation≤ 0.01% + 2mV
Ripple & Noise≤ 1mV RMS
Voltage Meter Accuracy±2% of full scale
Current Meter Accuracy±2% of full scale
Operating Temperature0°C to 40°C
Power Requirements100-240V AC, 50/60Hz
Dimensions215W × 130H × 280D mm

Safety Precautions

Before servicing the Kenwood PS 50, observe all safety precautions to prevent injury and equipment damage.

  1. Disconnect from AC power before opening the unit.
  2. Use insulated tools when working on live circuits.
  3. Discharge large capacitors before testing.
  4. Verify proper grounding of test equipment.
  5. Wear appropriate personal protective equipment.

WARNING! High voltages present inside the unit. Only qualified technicians should perform service procedures.

Installation Guidelines

Proper installation ensures optimal performance and safety of the Kenwood PS 50 power supply.

  1. Select a well-ventilated location with adequate clearance.
  2. Connect to properly grounded AC power outlet.
  3. Verify input voltage matches local supply (100-240V AC).
  4. Connect output terminals using appropriate gauge wire.
  5. Ensure proper polarity when connecting to load.

CAUTION! Do not operate in confined spaces or near heat sources.

Operating Instructions

Circuit Description

The Kenwood PS 50 employs a linear power supply design with series pass regulation for low noise operation.

Main Sections: Input rectifier/filter, reference voltage circuit, error amplifier, series pass transistors, current limiting circuit, metering circuit, and protection circuits.

Voltage Regulation: Uses precision reference IC and error amplifier to maintain stable output. Current Limiting: Monitors output current and reduces voltage when preset limit is exceeded. Protection: Includes over-temperature, over-current, and over-voltage protection circuits.

Block Diagrams

Refer to service manual pages 15-25 for complete schematic diagrams and block diagrams.

  1. Main Power Supply Block Diagram
  2. Control Circuit Block Diagram
  3. Metering Circuit Block Diagram
  4. Protection Circuit Block Diagram

Note: All diagrams show signal flow and component relationships for troubleshooting.

Calibration Procedures

Calibration ensures accurate voltage and current measurements.

  1. Connect precision voltmeter to output terminals.
  2. Adjust voltage calibration potentiometer for accurate reading.
  3. Connect precision ammeter in series with load.
  4. Adjust current calibration potentiometer for accurate reading.
  5. Verify both voltage and current meters match reference instruments.

Tip: Use calibrated test equipment with higher accuracy than unit specifications.

Maintenance Schedule

Regular maintenance ensures long-term reliability and performance.

IntervalMaintenance Task
MonthlyClean exterior and ventilation openings
6 MonthsCheck calibration accuracy
AnnuallyInternal inspection and cleaning
2 YearsComplete calibration and performance verification
As NeededReplace worn components and test safety features

Parts List

Genuine Kenwood replacement parts ensure proper operation and safety.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
No output voltageBlown fuse, faulty power switchCheck/replace fuse; verify switch operation
Inaccurate voltage readingCalibration drift, meter faultRecalibrate; check meter circuit
Excessive rippleFailed filter capacitorsReplace main filter capacitors
OverheatingBlocked ventilation, faulty fanClean vents; check fan operation
Current limiting not workingCurrent sense circuit faultCheck current sensing resistors and op-amps

Service Contact: Authorized Kenwood Service Centers only.

Technical Support: Contact Kenwood technical support for complex issues.

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