Touch Switch II
A touch switch is a switch that is turned on and off by touching a wire contact, instead of flicking a lever like a regular switch. Touch switches have no mechanical parts to wear out, so they last a lot longer than regular switches. Touch switches can be used in places where regular switches would not last, such as wet or very dusty areas.
Schematic
Parts
| Part | Total Qty. | Description | Substitutions |
| 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.
Title: Touch Switch II
electronic circuit
Source: www.aaroncake.net/circuits/
Published on: 2005-02-10
Reads: 1227
Print version: 
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