The circuit below was suggested by the Motorola Linear Databook of 1990. The component used is uncommon and the power can be between 7.5 and 12 V.
This alarm uses several sensors that directly trigger a sensitive relay. A larger relay can be...
This circuit was found in an old publicatio n from the year 1958. The circuit controls an external load by...
Found in the July 1994 Electronics Now magazine, this circuit drives a relay up to 12 V depending on...