AUTO DAY & NIGHT SENSING BULB HOLDER | IT WILL TURN ON THE LIGHT AT DARK | DIY

Now you can make your bulb holder automatically on in night and off during day time to save electric bill.

This project only cost 200 rupees or below. here we are using LDR light sensor module to sense darkness and light.

I also made a video of this project click here to checkout the video

In this project we are dealing with high voltage so if you don't know anything about what you are doing then please don't try this, we are not responsible if anything happens you.

To do this you need 

1. LDR LIGHT SENSOR MODULE TYPE DO (DIGITAL OUTPUT) 
2. 5V POWER RELAY 250V/10A
3. RESISTOR 1K
4. DIODE 1N4007
5. BC548 OR 2N4401
6. DOT BOARD
7.  ADAPTER  DC 5V 1A 
8. BULB HOLDER

PIN OUT

TRANSISTOR

RELAY

DIODE

PROCEDURE 

CIRCUIT DIAGRAM

1. Connect resistor 1K to DO pin of LDR module and connect other end of resistor to bc548 transistor base pin
2. Now connect the transistor emitter to LDR ground pin and collector pin of transistor to relay coil pin
3. connect other side of relay coil to the VCC pin of LDR module and connect a diode 1n4007 across relay coil but positive side of the diode should be connected to transistor collector pin
4. connect 5V DC adaptor positive wire to the VCC of LDR module and adaptor negative wire to the LDR module ground pin
5. Now connect Bulb holder one wire to the relay normally open (NO) terminal and another wire of bulb holder to directly power source. Now to complete circuit connect common (COM) terminal of relay to other side of power supply. 

Now make sure connections are okay and 230V side is insulated and then you can test the circuit and adjust the LDR module POT to set the trigger in low light or in very dark.

When Placing or adjusting the LDR make sure it is not facing directly to the controlling bulb light source.