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 circuit was found in the January 1994 Electronics Now magazine. The transistors are general...
We found this circuit in a Texas Instruments documentation from 1973. Other operational amplifiers can...
This commercial earphone receiver was manufactured in the 1960s in Japan. It was powered by a 9 V...