Found in the July 1980 Radio Electronics magazine, this circuit uses an integrated circuit from the time and a power Darlington. The Darlington must be equipped with a heat sink.
This circuit was found in a Radio Electronics from May 1965. FETs are from the time, but the...
This circuit can generate signals from 80 to 800 Hz with an amplitude of 0.3 V. We find it in a...
Because it uses TTL integrated circuits, this siren must be powered by 5 V or as indicated with D1 to...