''Smart'' watchdog safety switch

Patent · Tue Oct 01 04:00:00 EDT 1991

OSTI ID:7083830

Kronberg, J W

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. 21 figures.

• DOE Contract Number: AC09-76SR00001
• Assignee: PTO; EDB-94-111372
• Patent Number(s): A; US 5054023
• Application Number: PPN: US 7-350953
• OSTI ID: 7083830
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426000* -- Engineering-- Components
Electron Devices & Circuits-- (1990-)
ALARM SYSTEMS
DESIGN
ELECTRIC FILTERS
ELECTRICAL EQUIPMENT
ELECTRONIC CIRCUITS
EQUIPMENT
FILTERS
MONITORING
ON-LINE SYSTEMS
OPERATION
SWITCHES
SWITCHING CIRCUITS
TIMING CIRCUITS