This circuit was found in a 1970s General Electric documentation. This circuit already used an emitting LED. The circuit operates at frequencies from 50 Hz to 50 kHz with short pulses
This circuit has an LED indication of the timing progress, having been found in an old...
This circuit is from a Radio Electronics magazine from August 1974. It used one of the first...
This charger is powered by the car's 12 V socket, the number of diodes being calculated according to...