Smart watchdog safety switch

Patent Application · Fri May 12 00:00:00 EDT 1989

OSTI ID:6706731

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 open to stop power to process equipment. An interface module can be added to allow the switch to accept a variety of periodic output signals. 6 figs.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC09-76SR00001
• Assignee: Dept. of Energy
• Patent Number(s): PATENTS-US-A7350953
• Application Number: ON: DE90014585; PPN: US 7-350953
• OSTI ID: 6706731
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CONTROL EQUIPMENT
FAILURES
ELECTRIC CONTROLLERS
PROCESS CONTROL
MONITORING
SWITCHES
ALARM SYSTEMS
AUTOMATION
ENGINEERED SAFETY SYSTEMS
SAFETY
CONTROL
ELECTRICAL EQUIPMENT
EQUIPMENT
420200* - Engineering- Facilities
Equipment
& Techniques
320303 - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Equipment & Processes