We found this circuit in a 1957 Raytheon transistor publication. The circuit can be assembled with more modern transistors with minor changes. The handset must be high impedance magnetic.
We found this circuit in a 1965 General Electric manual. The circuit applies to incandescent lamps only and...
This simple circuit was obtained in a Portuguese publication in 1979 but can be easily assembled with...
In fact, it is a night light system that automatically turns on the outside lights when it gets...