Fluke 875 manual Nor, Pin Voltage State Comments

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Victoreen 875

Operators Manual

	8	L	Connected to 4	12	L
	10	H	Since U202, (8, 9, 10) is	11	H	Because 12 and 13 are L
	10	H	NOR	11	H	Because 12 and 13 are L
			NOR
	12	H	Result: Output switches			This is the original condition. No
	12	H	from Low to High			change takes place.
			from Low to High			change takes place.

Notes:

1)Enable pulse assumed present, so 1 and 5 are L.

2)Initial condition assumes 12 and 10 L.

The truth table shows that no change in the output can occur without the presence of the enable pulse, even though the monitoring signal indicates a fail condition. This is necessary because the ramp voltage starts from zero during the ECS Test.

Table 5-2.	Signal In Fail State (High Signal Input)

Pin 1		Voltage State	Comments
10, U208 and 6, U202		H	Fail state
9, U208 and 2, U202		L	After inversion
1,5, U202		H	No enable input
4, 8, U202		L	Because of NOR action
3, 13, U202		L	Because of NOR action
10, 12, U202		L	Because of NOR action

Thus the circuit does not react to a fail signal input unless pins 1 and 5 are low.

NOTE

If a problem cannot be resolved by applying the troubleshooting and maintenance procedures provided here, please contact Fluke Biomedical at 440.248.9300 for assistance.

5-12

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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-1Equipment Overview High-Range Containment Monitor DetectorRack 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 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 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 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