This circuit was found in a General Electric documentation from 1970. Equivalent transistors can be used. The maximum signal frequency for the indicated components is 250 kHz.
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...