This variable frequency circuit was found in a Popular Electronics from the 90s. The circuit outputs to a small speaker and can be powered by voltages as low as 3 V.
This circuit was originally intended for reading movie soundtracks. The circuit is from 1967 and...
This circuit is from an Italian magazine Elettronica 2000 of September 1987. It is a pulsator for...
Published in a February 1978 Radio Electronics magazine article, this digital circuit uses some of...