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Cupboard Lights Switch Circuit

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 NE555 and Reed Switch

Pin connections of IC 555

12 Comments

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  • anuja kunjalwar

    we r making timer in which irs on time is 10 mins n 50 min is off time
    how cab we proceed pls help
    thank u

  • not good

    this circuit is not working properly. light does not turn off after 3 min it glows continuously.

    • clarrkechotmail-com

      I built this circuit with little problems. You have to tie pin 2 to Vcc via a 10k pull-up resistor and put in switch ( I used a simple SPST switch) in series with the pull-up.Pin 2 of the 555 is attached to the 10k resistor opposite Vcc.The other side of the switch connecting to Gnd. The 9 volt battery just goes to VCC positive and negative to Gnd.

      The switch shorts pin 2 to Gnd or sets a low trigger pulse !

      You can set the off time by switching R1 to various values. I wanted about 1 and 1/2 minutes and used the schematics 100uf 25 volt cap and 825k resistor. This gave me about 1 min and 40 seconds of on time and it shuts off !

      I built this circuit because I wanted a light to light-up my shelf on my entertainment center.

      Note if you use a regular SPST switch you have to toggle the switch from off to on and then back to off so that the circuit will go off. You also could use a momentary push button switch.

  • J Singh

    Why not use joule thief circuit. It’s easy to make and can be used from almost dead batteries which are not useful for any application.

  • Mayur

    Hello Sir

    We have constructed the device as per the circuit given above. But the problem is that when I move the magnet away from the NC reed switch, the LEDs become ON and stays ON only. It does not get OFF in three mins as mentioned above.

    Kindly suggest what problem is there in this. I’ll be grateful if this can be sorted out.

    Expecting a reply soon. Thanks!

    • Ron E

      Perhaps a zenor diode in line with pin 2 and re-directed to (not across) R2 with a slight resistor to the LEDs to possibly prevent oscillation? The concept of this circuit is interesting.

    • T.K.Hareendran

      Yes, your observation is right. This is because of a design flaw; the trigger pin (2) of NE555 is tied to 0v/gnd rail, so the timer will not switch off after a pre-determined time. Needs a design revision!

  • Kandan

    Thanks a bunch, for Your immediate response Mohan.
    I will verify after including IC555 & 10uF cap, and keep You posted.

    Have a Good Day.

  • D.Mohankumar

    Thanks for your feed back. NC contact reed switch is necessary for the circuit. Then only the power supply breaks when the door is closed. You can procure the same from an old china make low cost door chime. IC 7555 is the low power CMOS version of 555.The problem is due to re triggering of the IC.Try with a 10 uf capacitor and see whether is it is functioning. Capacitor value determines the timing cycle-higher value ,higher time.Also try with 555 which is commonly available

  • Kandan

    Hello Mohan,

    First of all, ThankYou for the wonderful articles You have compiled and made available on the web.

    I am noobie to electronics (software is my fore) and tried my hands on the cupboard lights. I have some issues and would be glad if You could help me out.

    1) I couldnt find a NC reed, so I just used a NO reed to test the circuit. Is it possible to reverse the NO reed to NC reed (the popular way of using magnets is cumbersome for placement)

    2) I used IC7555 (couldnt find IC555) for the circuit and been having issues with the lights not turning off after three minutes.

    TIA.

    • william well

      Hi I

      Think you can put the NO reed between IC pin 2 and ground so when you open the door it will triggers the timer.
      try that and give me replay

      thx

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