Hello guys, today I am going to tell you an easy way to make an Automatic night light circuit(automation) without using any micro-controllers or development board. With a circuit diagram as well as a simulation video of working of this project. This is possible with a simple analog circuitry using some active components as well as some passive components working collectively. So let’s get started with Automatic Night Light circuit
So, lets first focus on the materials and components needed:-
- Transistor TIP122 -1pc
- R1 220K -1pc
- LDR1 -1pc
- 12v relay[SPDT] -1pc
- D1 1N4007
- 12v battery
- PCB board-1pc
- miscs like multimeter/solder,wires,etc.
Below is the circuit diagram and its working:-
Automatic Night Light Circuit
The circuit is employing an LDR (light dependent resistor), transistor TIP122, an SPDT RELAY 12V, and a small resistor 220K as components making this circuit working.
Working step by step:-
DAY TIME OR UNDER LIGHT INTENSITY
During the day time or when the light is falling over the LDR, its conductivity increases with a decrease in its resistivity, making the transistor working as the switch is turned off by shorting the base and emitter terminal also connecting the base to the ground and as our relay doesn’t get power to its coil, so no deflection happens within the pins and lamp or light does not glow.
In PROTEUS, I have used a torch to simulate day time and turned it off to simulate LDR under dark.
For NIGHT TIME/OR IN ABSENCE OF LIGHT
When in absence of light LDR doesn’t get that much light and its resistance does not decrease. So the base and emitter are not shorted and the base separately gets +ve making the transistor ON and emitter goes to the ground. This turns the relay ON and its pin deflects and connects COM TO NO.or in simple language we can say light is turned on via relay by completing the circuit by connecting it to mains 220-230V AC.
I hope You guys enjoyed this project and have understood the concept clearly. If you guys liked it, please comment below and let me know how you felt about this project.