Found in 90s Popular Electronics, this circuit fires a load through a MOSFET from an audio signal applied to the input. Power supply is done according to the load.
November 2016 - The TL3780 ultra-miniature E-switch touch switches can now be obtained from Mouser...
With this circuit, power cables can be detected by simply approaching PP. PP is an antenna or...
This amplifier configuration for instrumentation with two operators was found in a circuit manual...