Dark Sensitive Lamp ON/OFF Controller

  • Rajkumar Sharma
  • 11406
  • medium
  • Tested


Dark Sensitive Lamp controller project switches a load connected to it when light falling on LDR (Light Dependent Resistor)  goes bellow set point.  It could be used as an automatic street light application. The project is based on Triac and doesn’t requires additional DC supply, it works directly on 230VAC.


  • Mains supply input 230 VAC
  • Output load up to 500 W lamp / bulb
  • Snubber circuit
  • Sensor LDR
  • Screw terminal connector for easy input mains supply and load connection
  • Small size PCB
  • Four mounting holes of 3.2 mm each
  • PCB dimensions 37 mm x 49 mm
This project works on 230V AC, dangerous voltages can occur on the board and to equipment linked or connected to it. The operation should be carried out by qualified and authorized personnel only well respecting safety precautions.



Parts List






  • what the value of R3 100E?

    4 years ago
    • admin

      R3 is a 100 Ohm resistor.

      4 years ago
  • Suhail Paul

    what is the wattage of the resistors?

    2 years ago
    • Resistors are rated at 1/4W

      2 years ago
  • Chandrsekhar P

    How we can adjust light intensity in this circuit.

    1 year ago
    • Try to change resistor R1 with another value, but keep in mind that you work with MAINS and this can kill you.

      1 year ago
      • Norby

        My device was blinking in off mode what is the possible/recommendation to solve the problem?

        5 months ago

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