This CMOS integrated alarm was found in the July 1992 Radio Electronics magazine. The circuit has a small power stage and its sensitivity is adjusted at R5.
This circuit was found in the June 1995 Electroics Now magazine. The relay should be a sensitive type...
Frequency in this oscillator is given by C1 and C2. The circuit produces square pulses that can...
This circuit produces a 2 kHz tone on a standard piezoelectric transducer. The circuit can be used as...