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.
Found in a Motorola manual from the 1980s, this circuit uses components from the era. The circuit...
This circuit, which may have more inputs, consists of an optical OR gate using common...
Suggested by Amperex in a 1968 documentation, this circuit is based on TAA370, an integrated circuit...