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 high input impedance circuit was found in American documentation from the 1980s. The power...
This circuit shows on the screen of an oscilloscope two signals alternately at a frequency that depends...
This circuit transmits the signal taken from a telephone line to a receiver placed nearby (up to a...