This digital circuit is from a Radio Electronics magazine from December 1991. It does not use a microcontroller, but rather discrete digital circuits of the time.
This circuit uses a 741 operational amplifier that must be powered by a symmetrical source of 6 to...
This oscillator generates a 1 kHz signal, using an old germanium PNP transistor. The circuit was...
This circuit was obtained from a Radio Electronics issue from January 1989. The indicator is a...