This Cupboard lights circuit is an automatic White LED lamp used to illuminate the interior of cupboard to search things. The lamp automatically turns on when the door of the cupboard opens and stays on for three minutes then turns off.
The circuit uses the popular timer IC NE 555 for the time delay. Components R1 and C2 gives three minutes time delay during which the lamp remains on. Power to the circuit is obtained from a 9 volt PP3 battery. A magnetic reed switch is used for the automatic operation of the circuit. The Normally closed (NC) contacts of the reed switch break when the magnet is close to it if the door is closed. When the door opens, magnet move away and the contacts of reed switch closes and the circuit gets power. Since the trigger pin 2 of timer is grounded, timer triggers and its output become high to light the white LED lamp. Fix the reed switch and circuit in the frame of the cupboard and magnet in the door so as to keep them close when the door is closed.
Cupboard Light Circuit diagram
IC NE 555 and Reed Switch
Pin connections of IC 555
LED technology 555 datasheet