This circuit has visual and audible status indication using an oscillator. The circuit is from a Radio Electronics magazine from June 1991.
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...