Picture of IR Detector
In this Instructable I will show you how to make a simple infra red (IR) detector.
When your TV stops responding to the remote it is hard to tell if the TV is broken or the remote doesn't work. With this little pocket-sized gadget you will know.
Spying has become more and more accessible to the average man. Whit this gadget you can check if someone has installed a night-vision camera in you room or office.

First I am going to show you how to build it and then how to use it.

If you are just interested how IR remote control works got to step 7.

Step 1: Electronic Components

Picture of Electronic Components
For this project you will need a couple of electronic components,all in total 3$.

1. Fototransistor (IR_Transistor);( in this chase I used RadioShack 276-0145);(picture 2)


3.Micro switch.

4.330 Ohm resistor (picture 3)

5.An electronic solder board (holes)

6. 9V battery snap

7. 9V battery

8. Rubber band

(all of the electronic components can be bought at your local RadioShack)
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instead of using fototransistor i can use photodiode

Grafx4Life made it!6 months ago
I made one on a breadboard before I move on to making a treasure chest my son can open with his Magiquest wand. Lots of fun, thanks for this.
jconell11 year ago

I have been trying to make this on a bread board before soldering it and the LED lights up and stays on. Any reason why it would do that?

This might be because the detector is detecting the infrared light that is being emitted by the lights in your room. If you cover the tip of the detector with your finger or turn the lights on, does the LED still glow?

There are 3 different types of Photo sensitive Devices and they can look almost identical. I have bought plenty off E Bay and from sellers here and in China claiming they are such, but are in fact much cheaper less useful IR Photoresistors (LDR's) Black or clear in the same 3mm or 5mm package these make Nil output exposed to light, their Resistance just drops like in conell1 project I suspect. You need a proper Photo Transistor like the one listed, or similar like the Kingsbright L-93DP3C

gal-x-e1 year ago
but it is very weak :(
tnx anyway it was fun to learn :)
hlakhotia1 year ago

can we increase its range

hlakhotia1 year ago

can we use a ir led of a remote in place of fototransistor.

hlakhotia1 year ago

our body also releases heat so can we make a circuit to detect it .

mbucy1 year ago

This is a cool little circuit. I used almost an almost identical circuit to be able to close the doors on my TV/music component cabinet (extender). I just used a external power supply instead of the 9V battery. I used the imitter off an old control instead of the red LED. I love to see all the young people coming up with these ideas. MaBu.
sbanerjee41 year ago
Will it work if we build the circuit on a breadboard instead of an electronic solder board???
bertwert2 years ago
You could easily make this into a receiving end of a laser tag system by changing the led into an alarm and the micro switch into a switch that can stay on.
To make the sending end, connect a IR led to a battery, resistor and micro switch.
vader0ne5 years ago
I made one of these years ago when i was reparing VCRs. I put it all into a atari 2600 game cartage case and the remote head fits just right in the frount to test.
comodore (author)  vader0ne5 years ago
Nice! Do you have some pics of it? :)

I will have to find it ,baried somewere on my desk who knows, but when i do I will take some pictires of it as a whole and apart.

comodore (author)  vader0ne5 years ago
Really wana see your creation! :)
Hey Comodore I tried to uploaqd some pictures of this but 7 hours later i came back and it was still trying to upload....I can send you the pictures by email if you send it to me vader0ne@yahoo.com
Sorry Commodore ,I just found my IR tester and my Cammera.Made with old parts from a VCR and a Atati 2600 game case it was the right size for this project...Hope you like....Bill.
halo993 years ago
Wouldn't a 390 ohm be much more fitting for a 9v? Or does the transistor really put out that much resistance?
mscharf3 years ago
I want to be able to switch a single led on and off with the use of ir remote, I have been scouring the internet to figure this out and come up empty. Can someone please tell me how this is done? Do not need any thing fancy, just basic as possible.
so............ does this mean in theory you could build an ir aray on any digital camera and have a night vision camera?
Check out kipkays version
mraghib3 years ago
Dear Sir,

I think my detector is not working. When i connect it with the 9 volt battery the LED turns on from first only and when I bring it near to my tv remote and press the tv buttons nothing special happens! I have checked and rechecked the steps

Thank You
Did you check your polarity. I don't know if this will work abut make sure your polarity is correct. Good luck
Norikaeru3 years ago
I got a detector out of a a vcr that was being thrown away and when the switch is pressed the led lights up and stays that way with or without any tv remote, could the ir transistor be broken to just let current flow?
kjordaan3 years ago
what an awesome project i wrote a blog post on it here it is:

ondrikczech3 years ago
can i use led from tv remote as ir transistor?
WIll the red Led Flash to the binary code preset into the remote ?

Say if 1 is on and 0 is off If the code was 1 1 0 0 1 0 1 Would the Led go on on off off and so on
if you replace the led with a buzzer it would be pretty cool it be like beep, beep, off, off, beep, off, beep
With a buzzer, depending on what kind you refer to, it may need it's signal amplified or converted from a pulsed DC to a waveform (if the buzzer or beeper runs on low voltage DC, then you can ignore everything I just wrote :-)
i was thinking a low voltage one but thanks for the tip :)
Well, by low, I meant "very" low :-) There will be less then 3 v running through the LED, so it'd have to operate in that kind of environment
comodore (author)  stephenniall5 years ago
yup!  It's does just ask you explained!  
Ahh thank you . Will be going to maplins tomorrow to buy the components for this
comodore (author)  stephenniall5 years ago
Good luck and keep me posted on how your project goes!   :)
will post a picture tomorrow if i finish it !
is it tomorrow yet?
comodore (author)  stephenniall5 years ago
Great! Can't wait to see them!
I once took an old remote from a broken DVD player and took out the IR LED and soldered in a green LED. Then I could see the remote flash as I pushed the buttons. And if you wave the remote around, you can see the 1100101 patterns and you can see that they are different when you push different buttons. Of course only do this with a remote that you no longer need, not a good idea to do this just to find out if the remote is working!
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