This common transistor-based circuit provides power for 20 mA common white LEDs from a single 1.5 V battery.
This circuit was found in a Radio Electronics of July 1984. It consists of the traditional power...
This circuit detects frequency modulated signals that are not received by a photo sensor. The...
This circuit, from a 1997 documentation, is based on a pair of Motorola MC14026 dedicated...