This 8 W amplifier with germanium transistors was found in a Japanese documentation from 1967. The circuit is of the commercial type and is powered by two 12 V batteries or by a symmetrical source.
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...