The project is designed to develop a touch sensitive switch to control any load. A 555 timer is used in monostable mode to drive a relay to switch ON a load for fixed time duration.
The 555 timer is triggered by a touch plate connected to its trigger pin. The output of 555 delivers logic high for a fixed time interval as decided by the RC time constant connected to the timer. This output drives a relay which in turn switches ON the load for that duration after which is switches OFF automatically. Human body induced mains supply develops a voltage on the touch plate to trigger the timer.