Electronic Check and Double-Check (May, 1956)
Electronic Check and Double-Check
What has a lady wearing a fur coat to do with electronics? The schematic being studied by the miss in mink is the brain that will guard her valuable garment when she puts it in storage for the summer.
But how do we know that safety devices are always alert? After all, even electronic watchdogs go to sleep sometimes.
Scully Signal Company answers this problem with a new electronic “Fail-Safe” monitor system that periodically prods itself to make sure it’s awake. The circuit generates “make-believe” emergency signals at preset intervals. In effect, it gives itself a scare to see how it responds. If it finds itself asleep or loafing on the job, it sounds the alarm.
Adaptable to nearly any kind of automatic control, the circuit has already been incorporated in fire detection systems, machine safety controls, furnace flame monitors, liquid level gages, flow systems, aircraft safety devices, burglar alarms, etc. Risks due to failure of electronic safety devices are said to be virtually eliminated.