The integrated circuit used in this application is uncommon today. The circuit converts capacitances into voltages from 1 to 10 V for a capacitance range from 10 uF to 100 uF.
In the figure we show our first circuit that consists of a simple touch switch capable of driving a...
This circuit was found in an 80's Electronic Engineering. The power supply must be symmetrical. The...
This metal detector was found in a French magazine Radio Plans from 1977. The phone can be a...