"Smart" watchdog safety switch

Patent · Tue Jan 01 04:00:00 EST 1991

OSTI ID:868009

Kronberg, James W ^[1]

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1. 353 Church Rd., Beech Island, SC 29842

A method and apparatus for monitoring a process having a periodic output so that the process equipment is not damaged in the event of a controller failure, comprising a low-pass and peak clipping filter, an event detector that generates an event pulse for each valid change in magnitude of the filtered periodic output, a timing pulse generator, a counter that increments upon receipt of any timing pulse and resets to zero on receipt of any event pulse, an alarm that alerts when the count reaches some preselected total count, and a set of relays that opens to stop power to process equipment. An interface module can be added to allow the switch to accept a variety of periodic output signals.

• Research Organization: E I DUPONT DE NEMOURS & CO INC
• DOE Contract Number: AC09-76SR00001
• Assignee: Kronberg, James W. (353 Church Rd., Beech Island, SC 29842)
• Patent Number(s): US 5054023
• OSTI ID: 868009
• Country of Publication: United States
• Language: English

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