For signals up to about 500 kHz modulated in amplitude and transmitted by the power network, the figure shows the receiver. The circuit is from a Radio Electronics from February 1989.
This circuit is designed to activate an automotive alarm after 8 minutes of activation. Of course...
The coils determine the frequency of this oscillator that we found in the January 1996 issue of...
This simple timer can be used in many applications such as egg timer. The LED glows up when S1 is...