Automatic light on or off system

             In 1968, the first commercial LED lamps were introduced. Early LED lamps where inefficient and could only display deep red colours,  making them unsuitable for general lighting 

            In 1998,  China boosted LED research and demonstrated  the first LED Christmas tree. Philips lighting caesed  research on compact fluorescents in 2008 and began devoting the bulk of its  research and development budget to solid state lighting.

               Automatic room lighting system is a microcontroller based the project that automatically turn on or off the light in the room. The aim of this project is to automatically turn on or off the lights in a room by detecting the darkness. 

              It is  very simple homemade project using some electronic components are

  •  2 N 7000 transistor 
  • 12 volt relay (5 leg )
  • 470 K resistor 
  • LDR (light dependent resistor)
  •  9V battery 
  • Battery connector. 

How to make automatic light on/off system 

  • Take a first leg of 12 volt relay solter to third leg  of 2N 7000 transistor.
  •  Third leg of relay connected to 470 K resistor. 
  • Using LDR solder to middle leg and first leg  of transistor.
  • Battery connected to circuit, the positive terminal (red colour )of battery connected to third leg of relay and negative terminal connected to first leg of transmitter.
  •  It is very simple automatic circuit. 
  • The circuit connected the lighting system   to the first wires of relay and second wire to the centre.
  •  Connect the  battery to the terminal.
  •  Wiring is ready.
  •  The neutral of main power connected  to bulb and phase to relay.when the relay  activate, pass the bulb. When the circuit have dark,  sense the LDR and activate that relay and on the light automatically.
  • Amazon purchase Link

Leave a Comment