hey everybody,i'm going to make a dark /light sensor using a lm741 opamp .It is very easy and requires only very few parts and is quite interesting .read on.

questions for the instructables make to learn youth contest :
what did you make?
-i made a light/dark sensor based on the LM741 opamp using parts from my local electronic store.

how did you make it?
- i got the idea from a video about making a dark /light sensor using arduino,so i decided to make an easier version of it.

where did you make it?
-i made it at my school and entered it for my science fair.

what did you learn?
- i learnt how a op amp works and how to use it and all the cool circuits you can do using it.


-100k resistor x2
-4.7k resistor x1 
-photo resistor x1
-180 ohm resistor(i did'nt put a picture for this)
-lm741 opamp ic
-l.e.d(any color) x1
-jumper wires
-9v battery 
-9v battery snap and
- a breadboard

I have entered the Make to learn youth contest.Please vote for me and comment on my instructable. Thank you for viewing.
<p>yo ..i made this circuit and it works , i also presented a mini presentation (ppt) on this circuit ... thanks a lot .. you can see my ppt and work on http://techmess.page.tl</p>
<p>waw this circuit work for me =D =D thanks bro</p>
<p>may i ask? why do you have extra 2 resistor at pin 2 and 3 twisting tgt? my circuit can work but my led still light up when i close up photoresistor</p>
<p>this circuit doesnt work for me.. help needed</p>
<p>this circuit doesnt work for me.. help needed</p>
What contest have you entered this into? I might vote for you if I could see it.

About This Instructable


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Bio: I'm an electronics hobbyist.I have a humongous interest in electronics.I enjoy building circuits,experimenting with ICs and MCus and fiddling and opening ... More »
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