Hii friend,

Today I am going to make a circuit of automatic street light.This circuit will work automatically.In the morning light will be close automatically.This circuit is working with LDR.

Let's get started,

Step 1: Take All Components As Shown Below

Components required -

(1.) LED - 3V x1

(2.) Battery clipper x1

(3.) Battery - 9V x1

(4.) LDR sensor x1

(5.) Transistor - BC547 x1

(6.) Resistor - 20K/33K ohm x1 {In the picture two 10K resistors are connected in series to make 20K resistor}

Step 2: Pins of BC547 Transistor

This picture shows the pinouts of BC547 Transistor.

As pin-1 is Collector of this transistor,

Pin-2 is Base and Pin-3 is Emmiter of this transistor.

Step 3: Connect LED

Connect LED to the transistor.

Connect -ve pin of LED to collector pin of the transistor as shown in the picture.

Step 4: Solder LDR

Next we have to solder LDR.

Solder LDR to Base pin and emmiter pin of the transistor as shown in the picture.

Step 5: Connect 20K Resistor

Next solder 20K resistor to base pin of transistor and in the +ve pin of LED as you can see in the picture.

Step 6: Solder Battery Clipper Wire

Now we have to solder battery clipper wire to the circuit.

Solder +ve wire of battery clipper to +ve pin of LED and

-ve wire of battery clipper to emmiter pin the transistor as shown in the picture.

Step 7: How to Use This Automatic Street Light

Connect battery to the battery clipper and observe that when light is on LDR sensor then LED is not glowing and when light is not on the LDR then LED is glowing.

Uses : We can use this circuit as a street light because it will automatically ON and OFF.In the morning when light will come on the LDR then LED will not glow and in the night light will not be fall on LDR then LED will glow in the night and vice versa.

Thank you