Wiring Schematic Diagram

A simple electronic touch switch can be constructed using this circuit diagram . This electronic touch switch circuit is based on 2-transistors an can activate a relay. Putting a finger on the touch pads turns the top transistor ON and this transistor turns on the bottom transistor. When the finger is removed, the circuit consumes less than a microamp.

The touch sensor can be constructed using a small piece of a printed circuit board ( two small tracks with a 2 mm distance between each other ) . This circuit is powered using a 12 volts DC power supply , so the relay used for this project must be a 12 volts relay . This circuit is working very simple , when both plates of the sensor are touched the skin resistance will activate the circuit.