Simple Circuit for Every Electronics Beginners : #Automatic Night Lamp With LDR


Introduction: Simple Circuit for Every Electronics Beginners : #Automatic Night Lamp With LDR

About: Just a Simple Maker.

Hey, guys ☺

Looking for some beginning DIY projects in electronics..! then you have come to the right place

In this project, I'm sharing my first electronic project.
Which I teach to every new one in electronics......

New to electronics..!
You are welcome to this place
Let's learn ......

(only for beginners ,if you are an expert skip this project.....)

Step 1: Beginning......

First, let us learn about the electronics components used for this project

● Resistor:
Used as what its name says(resistance)
It provides a potential difference in a circuit.

● Potentiometer(pot meter) :

Using this we can change or adjust resistance by turning the knob or moving it.

● Transistor (that 3 legged thingies)

Used as an amplifier, automatic switch etc.(in this project we are using it as an automatic switch).

● LDR (Light Dependent Resistors) also known as cadmium cell:

LDRs or Light Dependent Resistors are very useful, especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000000 ohms, but when they are illuminated with light resistance drops dramatically

for more details visit this site

● LED (Light Emitting Diode) :

Gives out a light when electricity is applied to the respective electrode.

Step 2: Let's Start Building........

We are going to make a simple automatic light which automatically lights up when it's dark.

Step 3: Things You Need.....

1. 2N2222A transistor

2. 100k pot meter

3. 1k resistor (brown ,black,red codes)

4. 220ohm resistor

5. LDR

6. 9v alkaline battery

7. LEDs

8. Switch (optional)


they are available at less than 3-4$

● wire

● soldering iron and prototyping PCB (optional)
I first made it without soldering.

Step 4: Circuit Diagrams.......

Gather everything ......

Carefully follow the circuit diagram.

Note about potentiometer:

connect the middle and any other one pin of pot meter, leave other (as in picture 2 in this step) and connect it to the circuit.

Step 5: Transistor

A transistor has 3 legs middle one is the base (B)and other two is the collector (C) and emitter (E) respectively as in the picture for this transistor.

You may be confused at this point if you are a beginner(I also was confused at first,I learned from my mistakes). That is why I remind you learn from mistakes , and don't give up if you fail,try till you win(at least that is what happened to me......). That is what the Edison did before he invented the light bulb . So NEVER EVER GIVE UP.

Step 6: Have You Finished.....

All done.......

Ready to test........

Connect the circuit to a 9V battery positive and negative respectively.

(Please forgive me for my images ,if you didn't understand it.what do you expect , first tries,that too from a kid who does not have a soldering iron.......)

Step 7: Let's Test........

Take the circuit to a dark place or hide LDR with your finger and switch on the circuit
The LED should light ,if not adjust the pot meter( turn it or move it).

After the LED glows take your hands away from LDR or come back to a lighted area,the LED should turn off,if not again adjust the pot meter.

if it all works as said.

it's ready .

if not rewire the circuit or find the fault(don't give up).

Frequently adjust pot meter for better performance .

you're done....

when its dark LED glows automatically

when it is bright it switches off automatically.

And don't forget to improve my instructable.......
I will be back soon with another instructable.........

This circuit is not that much powerful to work with a relay.if you want a circuit which works perfectly with a relay just like this one.I have tried the 555 one but it is a little bit laggy. if you want a more powerful circuit you can visit this instructable

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77 Discussions

NICE! Especially the LDR gif animation! :)


1 year ago

hi there,

can anyone explain or show me best the way to interface switches and potentiometre as and input and LED as an output? and which system would you recomend to use in order to make it happen?

im stuck with my project.

My project is about lighting system in automotive... help help pleaseeeeeeee?!!!!

anyone out there?!!!!

Do u make arduino projects?


i want to connect 12v charger and don,t want to use 9v battery. what components to be used?


I want to make 220 volts direct drive LDR based lamp drive with minimum space to fit with same holder means transformer less even use triac or any solid state.

Please answer my message....

I made a very simple circuit using a 9v battery , a LED , and a LDR. But I lights when there's light and turns off in dark. Please help.

1 reply

I made it . Thanks...

Do u know I m just 12 years old , and I made that circuit on breadboard. ........

1 reply

I made it . Thanks...

Do u know I m just 12 years old , and I made that circuit on breadboard. ........

I made it . Thanks...

Do u know I m just 12 years old , and I made that circuit on breadboard. ........

I made it . Thanks...

Do u know I m just 12 years old , and I made that circuit on breadboard. ........

I made it . Thanks...

Do u know I m just 12 years old , and I made that circuit on breadboard. ........

Sir ,I want to insert a buzzer instead of an LED .please tell me which ae the other materials required for it & how to make it.please send me circuit diagram also.

3 replies

Just remove the LED and 220 E resistor and connect a buzzer in that place.Make sure that you have conmected the +ve & -ve lead correctly (ie,connect the +ve lead of the buzzer to the emitter of the transistor and the other -ve lead to -ve of the battery

sir if i want to insert both led and buzzer using two transister ,then what will be the circuit?

I m a beginner


2 years ago

hello sir. can you please tell me why my circuit isn't working when its dark and it works when there's light.

1 reply

U must have replaced the base of the transistor
ie. the middle leg of the transistor

Check the Diagram and redo it