How to make an Light sensor and Dark sensor

Picture of How to make an Light sensor and Dark sensor
 Hi Everybody... I'm Aryamaan, and this is my second instructable so please  give me advise and point out areas in which to improve.

Please after looking to my project give an honest rating.
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Step 1: Things that you will need

1)LM358 IC
2)LM7805 IC
3)2 LEDs
4)2 LDRs
6)3 9v batteries
7) wires
8)Two variable resistors of 10K

Please download the data sheet of LM358 and LM7805 IC.
Link of LM358-
Link of LM7805-

Step 2: Circuit Diagram

Picture of Circuit Diagram
Remember that the LDR doesn't have a negative or positive terminal.
Connect the first terminal of the LDR to positive and second terminal through variable resistor to negative.Then start varying and when you get a vary of example(.58 v to 1.1v).if the vary is of good range ,it will also work.then take a wire in between from LDR and variable resistor and put in the third pin of the LM358 IC.

Please make the circuit given in the diagram.
The circuit should be made in a good light.

Step 3: How the circuit looks

Step 4: How it works

In my circuit the left LDR is light sensor and the right LDR is Dark sensor.When you put hand on left LDR the 1st led stops glowing.
And when you put your hand on right LDR the 2nd led starts glowing.

IF you have any problems in this circuit you can comment or mail me at

Please Please rate this project.
Please Please????
akkisk7 months ago
Hey, this is Akshay.... studying engineering!
i made the exact copy of the breadboard connection in the pic. of ur.....
i din get any light illuminating from my led's....
but wen i made my own connections by looking at the circuit diagram u've put, both my led glows! no matter wat u do i'm not getting the proper thing over this!!!

oliverkellow8 months ago
Use Fritzing to mock this up, Its a great circuit and you explain it well, but yeah, the schematics are a bit rough.

Fritzing is drag and drop, very easy and no crazy variables like spice etc
mimah10 months ago
what is the use of
LM358 IC ?
I agree with dmartins, using any sort of circuit CAD software makes it much easier to follow. Multisim for example is a very easy software to jump into. As well as Pspice.
dmartins-12 years ago
Please use a program to draw the circuit. Like a Multisim, for example.
It is much easier to analyze.

Aryamaan (author)  dmartins-12 years ago
No Multisim would be difficult for other peoples who don't know much robotics.In fact using a program it would be more difficult.

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