This circuit is from the September 1985 issue of Radio Electronics magazine. The circuit has an LED charge indicator and is based on CMOS logic. The MOSFET 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...