Fluke 875 manual Signal Input Circuit, Mother Board P/N 876-1-78, Schematic 876-1-3A, Rear Panel

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Victoreen 875

Operators Manual

5.4Power Supply Measurements (P/N 876-1-89 Schematic 876-1-3C)

Turn the 876A-1 on by turning the function switch to the ALL position.

CAUTION

Allow all equipment, including the readout module, to warm up for at least 60 minutes before attempting any calibration.

Adjust the mechanical zero of the panel meter (use mirror scale to avoid parallax error) so that the needle is centered on the first hash mark of the black expanded arc to within 0.50 needle width.

Verify the output voltage of the power supplies as follows (See drawings 876-1-78 and 876-1-89).

Mother Board (P/N 876-1-78, Schematic 876-1-3A)

1.Connect the negative lead of the DMM to TP102.

2.Probe TP101 with the positive lead of the DMM. The DMM should read +24 ± 3 VDC.

Power Supply Printed Circuit Board (P/N 876-1-89, Schematic 876-1-3C)

3.Probe TP5 (white) with the positive lead. The DMM should read -21 ± 2 VDC.

4.Probe TP4 with the positive lead. The DMM should read -10.00 ± 0.01 VDC. Adjust R4 as necessary to correct this reading.

5.Probe TP2 with the positive lead. The DMM should read + 15.0 ± 0.2 VDC. Adjust R5 as required to achieve correct readings.

6.Probe TP3 with the positive lead. The DMM should read +14.3 ± 0.4 VDC.

PreamplifierIMeter Board (P/N 876A-1-86, Schematic 876A-1-3E)

7.Probe TP401 on preamplifier meter board with the positive lead. The DMM should read +6.200 ± 0.001 VDC. Adjust R413 as necessary to correct this reading.

Rear Panel

8. Probe the back panel high voltage connector, J2. The DMM should read +506 ± 10 VDC.

5.5 Signal Input Circuit

(P/N 876A-1-35, Schematic 876A-1-92 & P/N 876A-1-75A, Schematic 876A-1-

3B)

The signal input circuit is partly on the preamplifier board, and partly on the relay driver board. It consists of logarithmic amplifier U301 and its associated circuitry (preamplifier meter board) and amplifier U501 (relay driver board). The output of U501 provides the input for the meter circuit on the preamplifier meter board and the high and alert alarm circuits on the relay driver board. The alarm circuits are covered in the "Alarm Circuits" paragraph. The signal input circuit can be tested at two test points, using the CHANNEL TEST push button to provide a convenient input signal. Voltages at these points should be measured with no signal input.

1.Disconnect the cable connecting the readout module to the detector. Turn the function switch to TEST.

2.Measure the voltages at TP501 and TP502 under two conditions: 1) with no signal input; 2) with a signal input obtained by pressing the CHANNEL TEST push button.

The voltages should be:

No Signal

Channel Test Signal

5-4

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Contents Victoreen High Range Containment MonitorFluke Biomedical Table of Contents Calibration and Test Procedures General Description SpecificationsIntroduction Containment MonitorTemperature Operating 40 to 120F 4 to 49C Readout Module 876A-1High-Range Containment Monitor Detector Equipment OverviewRack Chassis Flexible Tubing 878-12-30TAB Pull Box AssemblyCables/Connectors/Panel Optional EquipmentHigh-Range Containment Monitor Typical Energy Response Curve Detector Typical Linearity Detector High-Range Detector, Recommended Installation Receiving InspectionProcedures, Warnings, and Cautions StorageBlank Readout Module InstallationInstallation Pull BoxSpecifications for Cable Cable SealingSpecifications for Cable Cable and Wiring InstallationDetector Test After Installation Detector Cable Inside ContainmentPower Connections P1 Ancillary WiringAll Alarms on P2 Normal Operation Shelf State Computer & RecorderOperation OperationVictoreen Functional Description Function DescriptionReadout Module 876A-1 Negative Power Supply FAIL/SAFE Comparison Circuit on Power Supply Board High Voltage Power Supply Normal Operation non-ECS TestOperation of High Voltage Supply During ECS Test High Alarm Circuit Alert Alarm CircuitRecorders and Computer Buffers Fail/Safe CircuitPen Clamp Panel Meter Action During ECS Test Meter at extreme lower end of scaleLow Voltage Ramp Generator Action of Green Safe/Reset Light and Alarm During ECS TestMonitoring Circuits of The ECS Board Block Diagram of ECS Test Safe/Reset Sub-circuits Muting Circuits of ECS BoardBlank Maintenance Maintenance, Calibration, and TroubleshootingCalibration Test Procedure TP876A-1-108 Troubleshooting PreamplifierIMeter Board P/N 876A-1-86, Schematic 876A-1-3E Signal Input CircuitMother Board P/N 876-1-78, Schematic 876-1-3A Rear PanelTP501 TP502 +6.3 Test Point Normal Channel TestMuting Stages of the Alarm Circuits High Alarm CircuitNormal Low Signal Level Channel Test ESC Board P/N 876A-1-92, Schematic 876A-1-3D Wave Shapes on the Electronic Check Source Board Overall Fail Circuitry Associated with the ECS Test Starting With Pins M and P on the Power Supply SchematicStarting With Terminal H on Relay Driver Board Outputs of U206 Pulse Generator on the ECS Board Operation of the Latch CircuitLatch Circuit Circuit assumed initially in Pass Condition Fail ConditionNOR Pin Voltage State CommentsCalibration and Test Procedures Blank Cable and Pull Box Procedures Cable and Pull Box ProceduresVictoreen Applicable Drawings Applicable Drawings and Bill of MaterialsDocument Number Description Detector Cable Out of Containment Applicable Bill of Materials Fluke Biomedical
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