Monitor circuit for a control rod drive mechanism
A monitor circuit for a control rod drive mechanism (crdm) that is adapted to detect erroneous stator phase sequences and generate a visible and audible alarm. The monitor circuit has particular application for use in connection with the control element assembly of a nuclear reactor. The monitor circuit includes an interface circuit for each stator phase winding of the drive motor, a plurality of logic gates to detect the predetermined erroneous phase sequences, a plurality of flipflops to maintain the fault condition signal, visible and audible alarm circuits, and circuitry for resetting the monitor circuit after a fault condition. The monitor circuit also includes a ratchet trip circuit for disengaging the clutch mechanism from the control rods when the rods are in motion in the time a fault condition is detected.
- Assignee:
- Babcock and Wilcox Co
- Patent Number(s):
- US 4363778
- OSTI ID:
- 6438176
- Resource Relation:
- Patent File Date: Filed date 15 May 1980; Other Information: PAT-APPL-149966
- Country of Publication:
- United States
- Language:
- English
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