We found this circuit in a 1968 Electronics World. It fires a buzzer if the ignition key is turned on and the headlight is off. The circuit uses an included oscillator buzzer like the Sonalert.
This 1989 circuit activates a protection relay if one or two phases are missing from a three-phase...
This simple TTL electronic dice uses common anode displays. The circuit is from a March 1975 Radio...
This non-pulse alarm can be used as an event detector or even an alarm. The circuit can also be...