In this project a switch is implemented that is turned on and auto off by touching a wire contact, instead of 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. This is achieved by operating a 555 Timer in monostable mode while its trigger point is connected to a touch pad. Human body induced mains supply develops a voltage on the touch pad to trigger the monostable of 555 Timer, the output of which drives a relay for time period as decided by the time constant formed by R and C of the monostable.
For complete information about this project, visit http://www.edgefxkits.com/touch-controlled-load-switch
