Poptronics recommends this circuit for use in the car when the headlights are left on. The circuit uses a sensitive relay with contact current according to the headlights.
The frequency of TTL square signal is divide by 5 with this circuit. Power supply is 5 V and the...
This interesting circuit was obtained from a Poptronics of February 2001. The American magazine no...
This circuit was found in an English magazine from 1983, but it can be assembled with BC548 for...