Simple Touch Switch

With touch switch, you can turn on and turn on a electronic device. Touch switch don't need mechanical part, so they will not worn out due to mechanical contact. Touch switches can be used in places where regular switches would not last, such as wet or very dusty areas.

Here the schematic diagram:

Component part list:

Part      Total Qty.    Description

C1         1          10uF 16V     Electrolytic Capacitor
R1, R2     2          100K 1/4 Watt Resistor
R3         1          10 Meg 1/4 Watt Resistor
U1         1          4011 CMOS NAND Gate IC
MISC       1          Board, Wire, Socket For U1

Notes:

1. The contacts an be made with just two loops of wire close together, or two squares etched close together on a PC board.

2. When activated, the output of the circuit goes high for about one second. This pulse can be used to drive a relay, transistor, other logic, etc.

3. You can vary the length of the output pulse by using a smaller or larger capacitor for C1.