The project is designed to develop a time delay based switch to control any load. A 555 timer is used in monostable mode to drive a relay to switch ON/OFF a load for fixed time duration.
A time delay based relay is a relay that stays on for a certain period of time once activated. This circuit is made up of a simple adjustable timer circuit which controls the actual relay. The time is adjustable from 0 to few seconds but can be increased by increasing the time constant of the mono-stable 555-timer. The current handling capacity of the load is limited by the kind of relay used. The project is offered with a lamp as a load.