The Auto switch off light circuit drives AC lamp up to few seconds and turn off the lamp this can be used in staircase or some other application where the few second lighting needed.
Circuit diagram for auto switch off light
Construction and Working
Here the 230 volt, 60W bulb is connected through 1 Amps bridge rectifier and TRIAC component to the main power supply, the gate terminal of TRIAC is connected with optocoupler MOC3041, this optocoupler is driven by the output of timer IC555, here the timer IC 555 produces timing pulse depends on the timing resistor and capacitor (R3, C2) components.
When we press the push to ON switch the load is connected with the main power supply and the timer IC gets supply, so it produces timing pulse, this will drive the opto coupler in few seconds the load disconnected from the supply through TRIAC.