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 was found in the September 1974 issue of Radio Electronics magazine. The circuit uses...
This medium wave radio works with any general purpose NPN transistor. The diode must be made of...
Found in a 1964 Electronic Design, this circuit suppresses arcs that occur in contacts when a...