With this circuit it is possible to obtain a voltage of -5 V from a 5 V source. The circuit is from Radio Electronics from May 1982. The maximum current is around 80 mA.
This immobilizer circuit for the car was found in the Radio Electronics magazine of December 1976....
This circuit allows the activation of a remote telephone bell made with a common piezoelectric capsule. The...
This circuit can act as a receiver for the transmitter of the previous circuit. We found it in...