Found in a 1980s American documentation, this circuit operates with 5 V signals requiring 55 cycles of 500 Hz for tone recognition. The circuit can be adapted to operate with other frequencies.
This xenon lamp circuit is from old documentation. The trip transformer has a 1: 1 turn ratio and...
This simple alarm with integrated CMOS sounds a piezoelectric transducer when the sensor circuit...
In the figure we have an interesting circuit for those with a project that requires a sub-multiple...