In one of the rooms upstairs in my house I have an Infra Red panel. When I am in that room and I switch on this panel I sometimes forget to switch it off, which is a waste of valuable energy. In order to prevent this, I built this Infra Red Panel Timer. Of course you can use this circuit for switching off other devices after a certain timeout.
The operation of this timer is simple. When you press a push button once, one LED is turned on, the Infra-Red panel is switched on and a timer of 30 minutes is started. Pressing the push button again will increase the timer value with an additional 30 minutes and a second LED will turn on. Since 4 LEDs are present, the maximum timer value is 2 hours. When counting down, the LEDs will indicate how much time is left so when only 1 hour is remaining, 2 LEDs will light up. If the time is passed, all LEDs are off and the Infra-Red panel is switched off.
During operation, the timer value can be increased with 30 minutes if not yet at the maximum value of 2 hours by pressing the push button once. If you want to switch off the timer before the timeout has passed, you have to keep the push button pressed for one second.
As always I built this project around my favorite micro controller the PIC but you can also use an Arduino.
Note that the project is switching the mains power of 230 Volts so be careful!”