Here is a great collection of touch switch circuits. A touch switch is an electronic device that enables us to control a circuit by simply touching a sensor. Simple touch switch circuit with 4011 – ...

This PLL-based circuit implements a touch-switch circuit using the PC board or small metal pads as sensors; it is radiometric and thus insensitive to changes in temperature and supply voltage.

We’ve seen it before, but [electronzapdotcom] reminds us you can use a 555 and a few parts to make a reasonable touch switch in this video, embedded below. The circuit uses some very large ...