We found this circuit in April 1979 Radio Electronics magazine. The circuit is based on the 555 and an integrated circuit of the time, including the audible warning and the activation of a relay.
This circuit uses an audio output transformer found in old transistor radios. Power output is...
Found in a 1967 Electronics World, this circuit uses unusual components today. The transformer has a high...
This circuit consists of a charge pump with positive input and negative output. We find it in a...