Automatic Night Lamp

Being fed up of turning lights outside on and off for night and day, I decided to make a simple relay controlled device which could do it automatically for me, automatic night lamp works using simple principles of transistors and light dependent resistors.

So let's get started.

Step 1: Things Needed

The components required to make this project are cheap and easily available at www.UTsource.net

1.) LDR (Light Dependent Resistor)

2.) 2N2222 (BJT transistor)

3.) BC558 (BJT transistor)

4.) 220K resistor (you may need to adjust values as per your requirement for how much light you need for the LDR to turn the circuit on.)

5.) 5V relay (to control AC mains lamp).

6.) 1N4001 diode (for protecting the circuit from back emf from the coil of relay).

Let's start building now!

Step 2: The Schematic

Connect everything to the schematic, I recommend first testing everything on the breadboard as I did in the Video tutorial before soldering everything on the breadboard.

Be sure to add the diode in reverse bias in order to protect the circuit from the back emf from the relay's coil.

Step 3: Testing the Project

I advise to test the circuit on low voltage first, as I connected 12V LED strip instead of 220V mains for testing, and you're good to go.

Have fun! Thanks for reading!