Fluke 875 manual High Alarm Circuit, Alert Alarm Circuit

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Victoreen 875

Operators Manual

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

A +6.2 V power supply contained on the preamplifier meter board has as its input the +15 V from the power supply board. Integrated circuit U401, pins 12, 13, and 14 is a voltage regulator with diode U402 providing a stable reference voltage. The output is adjustable by R413.

Relay Driver Printed Circuit Board (P/N 876A-1-75A, Schematic 876A-1-3B)

The signal input to the relay driver printed circuit board which is taken from pin 13 of the preamplifier meter may be monitored at this point through test point TP501. The signal enters pin 13 of OP AMP U501, and the output is taken from pin 14. The gain of this amplifier stage can be adjusted by potentiometer R503. The output of the OP AMP can be monitored at TP502; it provides inputs to:

•High Alarm circuit

•Alert Alarm circuit

•Meter buffer amplifier circuit

•Recorder/Computer drivers

High Alarm Circuit

The signal output to the high alarm circuit enter OP AMP U502 on pin 5. This is a difference amplifier, whose other input (pin 6) is determined by the setting of potentiometer R513. The main purpose of this stage is to control the high alarm threshold.

The output of the comparison OP AMP is connected, through diode CR504, to pin 6 of U503, which acts mainly as a power stage for the HIGH ALARM (red) panel light. The output of this stage (pin 7) also serves as the input to the high alarm relay driver stage U503, whose main function is to drive relay K502. The input to the high alarm relay driver stage of U503 is on pin 9, and the output is taken from pin 8. Relay K502 is energized in the non-alarm state, and a signal above threshold serves to de-energize it.

There is a red HIGH ALARM jumper connected to the collector (pin 8) of the relay driver U503. The following options are available with the presence or absence of the jumper when the radiation level exceeds the threshold and triggers the alarm:

Manual Reset - The alarm will continue to be activated even after the radiation level recedes below threshold until the SAFE/RESET indicator push button on the panel is depressed. This option occurs with the jumper in place.

Automatic Reset - The alarm will continue to be activated only as long as the radiation exceeds the threshold level. This option occurs with the jumper removed.

The red warning light acts similarly to the alarms. It lights when the alarm relay is de-energized.

Each relay contains four Form C contacts, but only two of the four are accessible through the rear connector.

The connection to the red panel warning light is from terminal 3 of the printed circuit board, which is connected to the collector (pin 7) of U503 through resistor R521.

Alert Alarm Circuit

The signal input to the alert alarm circuit enters OP AMP U502 on pin 3. This is a difference amplifier, whose other input (pin 2) is determined by the setting of potentiometer R509. The main purpose of this stage is to control the alert alarm threshold. The output of the comparison OP AMP is connected, through diode CR501, to pin 13 of U503, which acts mainly as a power stage for the Alert (yellow) panel light. The output of this stage (pin 14) also serves as the input to the alert alarm relay driver stage U503, whose main function is to drive relay K501. The input to the alert alarm relay driver stage of U503 is on pin 2, and the output to the relay is taken from pin 1. Relay K501 is energized in the non-alarm state, and a signal above threshold serves to de-energize it.

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Contents Victoreen High Range Containment MonitorFluke Biomedical Table of Contents Calibration and Test Procedures Specifications IntroductionGeneral Description Containment MonitorTemperature Operating 40 to 120F 4 to 49C Readout Module 876A-1Equipment Overview High-Range Containment Monitor DetectorRack Chassis Pull Box Assembly Cables/Connectors/PanelFlexible Tubing 878-12-30TAB Optional EquipmentHigh-Range Containment Monitor Typical Energy Response Curve Detector Typical Linearity Detector High-Range Detector, Recommended Installation Receiving InspectionProcedures, Warnings, and Cautions StorageBlank Installation InstallationReadout Module Pull BoxSpecifications for Cable Cable SealingCable and Wiring Installation Detector Test After InstallationSpecifications for Cable Detector Cable Inside ContainmentAncillary Wiring All Alarms on P2 Normal Operation Shelf StatePower Connections P1 Computer & RecorderOperation OperationVictoreen Function Description Functional DescriptionReadout Module 876A-1 Negative Power Supply High Voltage Power Supply Normal Operation non-ECS Test FAIL/SAFE Comparison Circuit on Power Supply BoardOperation of High Voltage Supply During ECS Test High Alarm Circuit Alert Alarm CircuitFail/Safe Circuit Recorders and Computer BuffersPen Clamp Panel Meter Action During ECS Test Meter at extreme lower end of scaleAction of Green Safe/Reset Light and Alarm During ECS Test Low Voltage Ramp GeneratorMonitoring Circuits of The ECS Board Block Diagram of ECS Test Safe/Reset Sub-circuits Muting Circuits of ECS BoardBlank Maintenance, Calibration, and Troubleshooting MaintenanceCalibration Test Procedure TP876A-1-108 Troubleshooting Signal Input Circuit Mother Board P/N 876-1-78, Schematic 876-1-3APreamplifierIMeter Board P/N 876A-1-86, Schematic 876A-1-3E Rear PanelTP501 TP502 +6.3 Test Point Normal Channel TestHigh Alarm Circuit Muting Stages of the Alarm CircuitsNormal Low Signal Level Channel Test ESC Board P/N 876A-1-92, Schematic 876A-1-3D Wave Shapes on the Electronic Check Source Board Starting With Pins M and P on the Power Supply Schematic Overall Fail Circuitry Associated with the ECS TestStarting 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 and Bill of Materials Applicable DrawingsDocument Number Description Detector Cable Out of Containment Applicable Bill of Materials Fluke Biomedical
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