In various countries, you may have seen that street light gets ON immediately when the night shows. This happens because these night lights use an automatic night light sensor. An automatic night light sensor is an electronic device that can sense the light sensitivity in the surrounding area & determine whether it’s day or night.
In this tutorial, we are going to make an Automatic Night Light Sensor Project. It has various applications and can be utilized at so many places at night.
Hardware Components
The following components are required to make Automatic Night Light Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Relay | SPDT/5V | 1 |
| 2. | LDR | 5mm/2mm/ | 1 |
| 3. | Transistor | BC547 | 2 |
| 4. | LED | 5mm/3.5V | 1 |
| 5. | DC Battery | 9V | 1 |
| 6. | Diode | 1N4007 | 1 |
| 7. | Resistors | 100 Ohm, 330 Ohm, 1K | 3 |
| 8. | Soldering Iron | 45W – 65W | 1 |
| 9. | Soldering wire with flux | – | 1 |
| 10. | Veroboard | – | 1 |
| 11. | Jumper Wires | – | As per need |
| 12. | Battery clips | – | 1 |
BC547 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of BC547
Automatic Night Light Circuit
Working Explanation
To understand the working of this circuit, one must need to understand the working of an LDR. The light-dependent resistor functions when there is darkness around. In normal conditions, when there is light, The resistance in the circuit can’t allow the electric current to flow. However, when the night comes and LDR faces the darkness, the resistance gets decreased, allowing the current to flow. This triggers the first transistor of the circuit which is working as the control signal for the second transistor. The output is coming at the collector of the second transistor which is there to energize the relay coil. Thus the relay gets ON.
Applications
- This circuit can be utilized in an automatic street light.
- We can use it in dark areas to work as the emergency lights.
- The circuit is great for the areas facing load shedding problems at night.
- The mine workers can also use it.
