This circuit from an old documentation includes the power supply for the 117 V power grid. It can be adapted to other networks by changing the 10k resistors.
The circuit presented is based on a mechanical tuning fork. The circuit is suggested by National...
This source, from a 1982 documentation, uses a triac to control the power and voltage applied to...
This circuit was found in a 1990 Electronics World magazine. The circuit can be mounted today by...