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)

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!
vectrasj4 years ago
All respects!
But You do not need to built this!
- You have a mobile phone with camera (any format)
- Turn Your camera on mobile phone ON
- Point camera at front of remote (20-30cm)
- press button on remote
- if button send IR command You will SEE white beam from the IR LED!
- Repeat press all buttons on remote and check IR LED response !

One reason TO make this is to have a seperate circuit to work with for other projects: sound sources, turning on or off other switches, etc with IR, ...there are a host of reasons TO build this; even if only to learn how it works.
some people dont have a camera and i think this is a neat project
Hycro6 years ago
I once had a stereo that if I were to hold the switch on my halogen bed lamp close enough to the on position that it would make the light flash, I could make my stereo open/close the CD drawer, or even change the volume, depending on how close or far the contacts of the switch were apart.
comodore (author)  Hycro6 years ago
That is very interesting, I never heard something like that, but I can bet you there is a scientific explanation for it! Hmm, interesting, tell that to teck-king, he might have an explanation....
I wonder if one of the LED's isn't "detecting" the signal? That can happen, but normally only if there is a voltage already applied to the circuit.
possibly the halogen lamp emits a flickering ir signal (all heat consists of ir rays)from the mains 60Hz/50Hz and then the device gets "confused"?
Sounds very likely...I didn't know then what I know now about that kind of stuff, though it's marginally more now...XD
Hycro comodore6 years ago
Oh likely, but it was still neat to do. I think the stereo that did it was the one I also blew the amp in...
comodore (author)  Hycro6 years ago
Haha! How did you do that? :)
Hycro comodore6 years ago
I had so many speakers connected in parallel that the resistance went below the amp's tolerance, and since it was under warranty, I didn't take it apart to see exactly what happened, but it likely overheated, and probably didn't have an automatic thermal shut-down, I tried it the next day, and still didn't work. It was designed to use a 6 ohm speaker per channel, and I had 6 or 7 8 ohm speakers connected in parallel, thereby reducing the resistance, essentially shorting the amp, or even overheating it. That's another reason why I like the amplifier ICs for car stereos, they have internal short and thermal overload protection, and operate at anywhere from 11VDC to 18VDC without damage, though the manufacturer states the optimum performance is usually at ~13.4VDC to ~15VDC. (Manufacturer states that is the standard charging voltage for a lead-acid battery being charged by the alternator in the car.)
comodore (author)  Hycro6 years ago
Well, I am a n00b in electronic, meaning I started to learn it not while ago..I understan, I think I do, what happened, it probably overheated, it was just too much for the amp to take... But, I know that in newer devices, by the IC, or a transistor, they put a thermoresistor, NTC, I think it is.... So if it gets over heated the resistance value rises and like a switch, cuts of the circuit...or a thermal switch.... :)
Hycro comodore6 years ago
Yea, most car stereo amplifier chips that I've researched have that capability.
toogers5 years ago
for awesomeness, replace the red l.e.d. with a piezo buzzer, and hide somewhere it will sense the i.r. rays.
Are you sure that would work without any other modifications? Don't you need to have an analog voltage going into the speaker to have it make a noise?
Two things: 1. Alot of piezo buzzers have a circit built into it that makes it buzz when a dc current is applied. 2. All voltages are analog, you are looking for the term AC.
Yes, he meant a wave form signal, in so much that a bare bones piezo would need such a signal to operate .
jack0024 years ago
I use my camera in my phone. You dont even have to take a pic, just look at the screen while holding the remote towards it.
This works with most digital cameras
phevtron4 years ago
ok but whats the range? can be used to switch lights etc?
If you used a relay it might be possible.
techno guy4 years ago
Isn't 9 volts a little too much for LEDs even if you have a 330 ohm resistor? Unless the ir transistor provides a lot of resistance.
It depends on the amperage rating of the source, the voltage drop across the LED, and the amperage rating of the LED.
techno guy4 years ago
If it measures heat, then can you replace the red LED with an analog meter and measure heat?
crtn24 years ago
you can use 3V button cell battery to make this thing smaller.
(replace 330 ohm resistor with lower value for voltages <4.5V)
account3r24 years ago
please respond quick, what voltage do the leds need to be?
usualy around 3 volts at the most
wat stops it from sensing other light sources, why deos it only detect IR
Most of the time, the surface of LED is made such that it filters out visible light and detects only INFRA RED
pawan g4 years ago
nice... a simpler way to detect IR, simply place the transmitter in front of a digital camera...i use this method to check for worn out LEDs ;)
I'm just wondering (because I don't know a lot about electronics)
Why do you have the switch? because I THOUGH that the photo transistor acts as a switch of sorts. no?
metsfan19384 years ago
Isn't 9 volts too much for the IR LED? The 330 ohm resistor does make much of a difference when it normally operates on 1.2-1.5 volts.
geeklord6 years ago
so if you took out the IR LED in a remote, hooked it up in a circiut with a 3V source, and a switch, and pressed the switch on and off in binary code, you could potentially control any IR device as long as you knew what the code was?????I am so smart......:D
No, unless you can tap out binary code ridiculously fast. Your remote sends out the pulses rather quickly, so you probably wouldn't be able to do it your self, it needs a microcontroller and what not to work.
But in theory, you could if you or something else could tap it out
In theory yes, yes you could tap it out.
you can use an arduino or pic microcontroller of something similar(eg; seeduino, lilypad, freeduino...) and program it to send codes, this instructable,http://www.instructables.com/id/Fart-Operated-Random-Channel-TV-Remote/, helps a bit (Whithout the fart sensor) or http://www.arcfn.com/search/label/arduino also's ok. but, for this you need intermediate programming knowlege and one of the devices listed above. anything else is probably futile.
In theory, you could. But in reality, your finger would have to touch the button 38,000 times per bit ! Or, just set up a 555 timer to do the 38Khz part
at 3 vdc you might want less resistance. try 47 ohms(40 calculated). IR leds have a much lower forward voltage than all other LEDs. one batt(1.5vdc)might work if only left on for a short while. usually IR has a 1.2 vdc forward voltage or about that. also a phototransistor has 3 leads. there is no connection to the base. u can do the same w a photodiode which only has 2 leads.
bestboy54085 years ago
看不懂功能ㄟ= =
comodore (author)  bestboy54085 years ago
Hycro6 years ago
On one of my remotes I could see the IR emitting LED actually emitting visible red light in very high speed pulses, maybe it's wavelength was close enough to visible light that you could see that anyways on it.
comodore (author)  Hycro6 years ago
In a way, you can see it, but very, very faint, but it is a little bit fisible to the human eye....
Time to go into the dark room, and stare at remotes until our eyes get dark adusted.
comodore (author)  natman34005 years ago
aks111 Hycro5 years ago
May be your eyes has ability to view infrared :).
farlepet5 years ago
I think fototransistor is spelled phototransistor. :)
lmao! haha right!
comodore (author)  best_brothers5 years ago
yea, my English is way better now ! :P I hope so!
pro2xy farlepet5 years ago
Yeah, right... :P
aviksaras5 years ago
is it necessary to use only that fototransistor? i have used a cheaper one it is a sensor the shopkeeper told it little bit works like IR sensor
comodore (author)  aviksaras5 years ago
You have a big variery of them so I am just going to say that most of the cheap ones will work just fine...
aks1115 years ago
Can we make similary the UV detector?
comodore (author)  aks1115 years ago
to be honest, I am not sure what acctually detects UV rays.... :) I would need to do a bit of a research on that! :)
w477s6 years ago
Hi, can i use reversed IR led diode instead of IR phototransistor?
yeah, you can...!
so is that just an IR diode wired backwards? Instead of waiting for a response I think ill just go ahead and try it...
Oh, I thought he meant an IR photodiode. An IR led wired backwards won't work.
Too late! good think I have 20.
o_Ops! xD i have about 40 of them :S
bigstiffy w477s5 years ago
A IR led wired backwards will actually work, at least it did for my circuit (although I used a different schematic). Here's the schematic I used if you're interested: carlitoscontraptions.com/2007/09/ir-detector/
ir photodiode != ir led diode? holly crap -.-
jules155 years ago
i did this, it didn't work..
comodore (author)  jules155 years ago
Mr Android
You must have soldered something wrong, or wired the phototransistor or LED the wrong way...
or maybe you just have a cold solder connection.
This is a very simple project and it was tested over and over again and proven that it works!

Thank you!
anil yadav5 years ago

actually i made one ir detector by reading your instruction but it is not working so pl ans my few question?
is the blinking of led can be seen by naked eyes ?
actually i tried to test but the led doesnt blink so is there is any other way to test the ir detector?

I actually can see a red like light... but, it is visable only in a darker place... toher technik..

Take your cell phone and watch through the camera... you'll see the lila light on the screen!!!!! 
your led must be damaged..coz i tried n its working perfectly...
comodore (author)  anil yadav5 years ago
You point your IR LED from your remote to your Phototransistor on your device that you made and you press any button on the remote while holding the push switch on your IR detector that you built (in case you have a switch like i do)
The led, in my case a red one, should start to blink as the IR led on your remote does, accept you can only see the blinking led on your detector, not the IR led on your remote.
Make sure that you wired everything up correctly, make sure the LED pins are as they should be placed!
Also make sure that your remote is working! You can use a standard camera or your phone camera, point it at the IR LED on your remote and see if, when you press any button the LED blinks.
Are you sure that you got a Phototransistor and not some other component, they look just like LEDs in some cases, in my case also!

Check all this and get back to me when you have some news or more questions!
TaylorTech6 years ago
If I were, to say, replace the LED on the detector with another LED, but this time, an IR LED,would I be able to create a low cost IR repeater/remote control extender?
comodore (author)  TaylorTech6 years ago
WoW, I never though of that... Try it your self, it is really easy... Please update me with the results you got...:)
Hey will do man, ;) Just let me pop out to The Source, and I'll get back to you! :)
comodore (author)  TaylorTech5 years ago
Any progress?
Darn, no. 8(. I know It's been nearly a month, but apparently The Source (Canadian Radio Shack) is out of stock (everywhere) and will restock on these cheap kits (emitter/receive) very soon. Unfortunately they are the closest tech store too me, 10km away. I'll try and go into town (Ottawa) soon, and check out an independent store, as I can't find anything online. Don't worry though, I am always checking up on the comments in this article, and have left a sticky not on my windows vista sidebar. :)
comodore (author)  TaylorTech5 years ago
To bad, how come they don't have these, it is not like you are trying to buy an atom smasher... :P Well, when you get back from Ottawa, leave a comment on your progress... :D I corentlly have lots of projects on my plate and really cant find the time for one more, even if it is really interesting like this one... Hope you get back to me soon! :)
Hell, it took a while to get these. I'm holding them in my hands right now. I'll get back to you soon with the results!
yep, it works! I will note however though, the light is very dim. I built a more efficient model with an added resistor and  NPN.

I'll create my own instructable soon enough.  :)
comodore (author)  TaylorTech5 years ago
Great!  I am very glad that you achieved this after so long!  :D
I can't wait for your instructables!
Be sure to inform me when you publish it!

pennsteve5 years ago
Instead of an LED that lights up when the photoresistor detects IR light, could I use a small buzzer?  I guess I could, right?  Instead of using a momentary switch, I can just use an on/off switch.   Right or wrong, anyone? (I'm still trying to make that annoying buzzer practical joke) 
comodore (author)  pennsteve5 years ago
Yup, sure, you can put a piezzo buzzer instead of the LED...
You can remove the resistor to get a bit more buzziness...
Any switch will do, weather it is a momentary or on/off one...
Good luck with your project !  :)
When it comes to emitters and detectors, nothing seems to work.  I am using this emitter and detector: http://www.radioshack.com/product/index.jsp?productId=2049723

Am I using the wrong stuff?  Hooking it up wrong? 
Battery+ going to detector+.... detector- going to resistor.... resistor going to buzzer+.... buzzer- going to battery-. 

I left out the switch for now.
comodore (author)  pennsteve5 years ago
They look ok!  It probably won't work on long range but will do on close!
Make sure that you hooked it up correctly. The long lead is the positive one and the short is the negative.
Try with 1 LED for now and when you got that working hook up the buzzer...
It would help if you could post some pictures of what you did so i get a better picture...  

Hope I can help you more!
Feel free to ask any more questions if you have! 
northconnor5 years ago
I thought that was pretty good for someone who doesn't speak English...
comodore (author)  northconnor5 years ago
Thanks  :P
I'm thinking using this with a motor ,so when you push a button on the remote will make the motor working.Is going to work?
yeah it should work... if however the photodiode has too high a resistance then i would use a transistor to amplify the signal... nice and easy so whats the idea for this thing anyway? i can think of ways to make each button on the remote make the motor do a different thing so theres more applications there...
comodore (author)  raykholo6 years ago
How can you make that? You need a programable micro controller of some sort...
yes you do however, it is possible to base this on the way that rf works. the signal oscillates at a certain frequency and then the receiving end has a resonator tuned to pick up that frequency... instead of an antenna, use a photodiode and a custom ir remote, with each button hooked to the ir led in series with a certain frequency oscillator. the robot would then use respective resonators, each wired to a transistor to activate the motor (s) or other functions... Bit of a far stretch, but i think theres a lot of potential and room for improvement here give this a thought, tell me what u think
comodore (author)  raykholo6 years ago
You got this worked out! Why don't you try to build it?
that was actually an idea off the top of my head... i currently do not have the components though, so i might put it on the next order i make it will have to wait... still like u said, u need a microcontroller here and i like that idea more its stable, and simple...
comodore (author)  raykholo5 years ago
I agree. What microcontroler will you use? Arduino? :P
Arduino is pretty good for a variety of options but i prefer to work from scratch (again, havent actually done this but i prefer the idea of working from the ground up) Also, I am currently involved in the First Robotics Challenge at my school so I am going to run gearmotors and servos off an NXT brick (over NXT bluetooth connection and using hitechnic motor controllers) Totally against what i like to do but its a generic kit for each team with those components and custom cut metal parts for the body As far as your question, an Atiny hooked up to relays and a photocell should work just fine. remember a diode in series with relays to prevent crosstalk over the lines.
comodore (author)  raykholo5 years ago
First Robotics Challenge? Sounds like a great fun! If you ask me I don't fancy programing so I don't usually use my Arduino, I prefer analog electronic.... :P
thank you. first is an acronym btw, not literally 'the first..'
speaking of analog electronics, that is something i also prefer at the moment because analog = linear = less variables = less problems = easy to predict outcomes. Check out my new model rocket launcher instructable here for a nice idea of that. "smart" yet no microcontrollers, no unforeseen obstacles, and a generic way to accomplish my goal with ease, yet also style and class.
comodore (author)  raykholo5 years ago
Nice Instructables... BTW I also have the program that you used to picture the electronic circuit, can't remember its name... :P My point also, better to assemble on a bread board that tire your self with codes and commands that don't work if you misspell or forget a a symbol... I am working on a halloween project I need a chip ISD1110 voice record/playback witch I just can't seem to find... Could you help me locate one please. That's Winbond Electronics ISD1110 voice record/playback chip. Thanks!
 programs called thinkin science zap
chip is shown on digikey website but u need to call cuz its out of stock... might be possible to get on in but i doubt they will do it for such a small quantity
have u looked into other similar chips?
comodore (author)  raykholo5 years ago
I was looking for a similar chip but I didn't find any that could replace the ISD 1110.
my only suggestion then would be to call digikey and see what they can do for you
again, small chance that they will do anything
also it might be possible to call the company directly but if its a discontinued product then sorry i got nothin
w477s comodore5 years ago
yay! relays and transistors!! :D
raykholo w477s5 years ago
 yep thats what i do
check out my rocket launcher instructable as mentioned above to see analog taken to a new level.
relays are good but draw too much current though so i guess they came up with semiconductors 4 a reason then... :)
w477s raykholo5 years ago
ssr uses tiny current (solid state relay) :P
Goodhart6 years ago
Do you ever get any false readings from ambient light sources? Back a few years I made something similar, but a little more complex in the circuitry to eliminate sources outside th frequency range (now where did I file those schematics....*sigh*). But it is a bit harder to build then too.
comodore (author)  Goodhart6 years ago
hmm, I don't use it often,but when i did I dodn't get a false reading. I used to se if my remote was working 3 or 4 times, and once to see if the IR LEDs on my brothers camera were working... If you find the schematic please share it, if not in a comment pm me, i am really interested to see how the circuit acts as a filter... oooOoOO yea, maybe there is like a filter that only lets IR beams, light, pass, I don't know... :)
Well there are such filters, but I thought the one I spoke of used some comparators to check a frequency range. I could be wrong. I have the device on my back desk somewhere but the schematic may be even harder to find :-)
comodore (author)  Goodhart6 years ago
post some pics of the device, i would really like to see it. Thanks!
I WAS wrong....it uses 1/2 of a Quad Op Amp (LM324) to take a signal from an IR detector transistor.... The first one shows the front side where the detector is, the second, the top where the button is and the third pic shows the inside with the bottom off the box......I didn't have much money to spring for decent boxes at the time, so I put it in an old cardboard box with a clear plastic lid :-) The battery needs charged or I would show that it does work.
IR Detect1.jpgIR Detect2.jpgIR Detect Guts.jpg
comodore (author)  Goodhart5 years ago
I am working on my Halloween project and I need a high range IR detector and mine just wont pick up IR light at a distance of 50cm... and I need a detector that will pick it up at about 1.2m or more.
Can you detector do that?
Did you find the schematic for it, or do you know any other schematic for a high range IR detector?  :)

Thanks!   :D
I haven't found my schematic, no.   There are IR detectors used in some intruder sensors (you know, like the beam across the doorway thing), and some passive sensors use both an IR beam and a sensor to sense movement within a room.  I haven't any schematics though at the moment.
comodore (author)  Goodhart5 years ago
To bad!
Anyway, I was googleing the High range IR detector and didn't find much... I just need an amp to put to make it able to catch the IR light from larger distances...
Once you have that, be sure to do something to make it somewhat directional, or you will get all ambient IR (especially in the daytime) in the area.
comodore (author)  Goodhart5 years ago
Thanks for the advice!  :)
comodore (author)  Goodhart6 years ago
soo, the green LED flashes if you detect an IR signal, right??? is that a 9v battery? The device looks interesting... I asume that it can detect IR on longer ranges than mine, that much better. I have worked a couple of projects whit an amp LM324, the name is very close to me. :) It looks very interesting. If you find a schematic for it, please if you have time, make an Instructables on how to make one of these, this is a great device!
Thanks, I will. And when I build it a second time, I will put it in a nicer box too :-) Yes, that is a 9v (NiCad) battery. The LED doesn't really flash. I have a capacitor that smooths out the signal so that the amplified pulse is steady and the LED comes on solid. Sadly, this really needs a small tube or some other enclosure around the IR transistor (that you can aim the remote control into), since direct sunlight (or sometimes even BRIGHT sunlight) will give a false reading (since sunlight contains IR).
comodore (author)  Goodhart6 years ago
Well. just put a piece of paper around the phototransistor, I think that should eliminate the sun factor... Have a great time building it, I believe you will! :) You can even make a box for it, from plehyglass so you can see all the electronic inside...
If I ever find my big IR filter, I can build it all behind that, and everything except IR will be filtered out :-)
comodore (author)  Goodhart6 years ago
good luck finding that! :-)
Yeah, I bought 2 or 3 of them quite a few years ago from American Science and Surplus (the catalog of junk dealers). And really haven't had much use for them until recently.
comodore (author)  Goodhart6 years ago
Suddenly you have so much uses for them... Yea, that is why I keep all the junk I salvage from broken stuff, and they come in handy or are a crucial part of my project... I was thinking of making a series of Instructables that would be called TAKE APART: and in those Instructables I would give a video, as well as steps on hot to disassemble some electronic devices, for example, an optical computer mouse, transistor, old modem... also what electronic components, like resistors, capacitors, diodes, LEDs you can salvage from that device... What do you think about that? Be honest please! :D Thanks!
Hmm, either name it Take Apart or Reverse Engineer or even Disassembling

Depending on the reason for taking them apart, you could even use Salvageing Parts.

comodore (author)  Goodhart6 years ago
hmm. yea, as I sad, It will be about, what parts you can salvage from the broken or non broken electronic devices.... I like the name Reverse Engineer... I'm still thinking on whether I should make this, looks like I wont... I'm still thinking... I want to make a few Instructables like, DIY Electronic Methronome, and I want to enter the plastic bottle contest, and i got a ton of project.... so ill see. Thanks for the suggestions! Thanks :D Keep you posted on my decision...
Rendydevara5 years ago
does fototransistor same with ir on remote? 
comodore (author)  Rendydevara5 years ago
No, on the remote you have IR LED.
While in the TV you have the IR Receiver or as it is called Phototransistor.
Rendydevara5 years ago
cool and simple...
how far the maximum distance of tv remote to IR detector ?
can i use it as a swicth ?
beehard445 years ago
i was thinking if you have a bunch of these infrared transistors scattered throughout the house and everything wired in parallel (that is the transistors) and having the LED as a infrared type and having it in front of a sound system. You can change the volume, station, etc. without having to go to the sound system, right?
comodore (author)  beehard445 years ago
I guess so, like a switch, yes... One one these days I am going to make my home lights turn one by the press of a button on any remote. :)
Farfar5 years ago
An easier way is to use your cell phone camera or digital camera and point the remote at the lens. Press any button and the remote and you will see the LED flash. It might just be that the batteries in the remote that is bad. ;-) Of course not as fun as building a nice prototype.
szechuan536 years ago
irs r so l33t use a ir led for emmission and detection of ir light yay
comodore (author)  szechuan535 years ago
rajsunil6 years ago
i liked it
comodore (author)  rajsunil6 years ago
Thanks! Nice and Easy! :P
Wesley6666 years ago
you could just use a digital camera as most see IR light. Plus the IR LED's look cool.
comodore (author)  Wesley6666 years ago
I am very very bored with this suggestion as you are the 9999 person to tell me that. I know I can use a camera!
Oh, sorry. But they do look cool, they are sort of a purple color.
comodore (author)  Wesley6666 years ago
Yea... :P
iandlacy6 years ago
i would have used an on/off switch so that you could leave it on. but this is cool...i didn't know IR was so...simple. i noticed you held it close to the remote, shouldn't this work to detect any ambient ir signals floating around the room....because if you have to hold it close, this wouldn't work to detect infrared cameras : /
comodore (author)  iandlacy6 years ago
Well, depends on how much Phototransistors you have... The more you have the better... than the intensity of the IR light...and offcource, how close you are to the source. Mine is as simple as it gets with only 1 phototransistor, so that is why i have to put it so close... IR cameras have number of IR LEDs, about 30-40, sometimes more and emmite much more IR light...than just one IR LED from a remote... Try connecting more phototransistors together... :D
raykholo6 years ago
personally, i would use 2 coin cell batteries with thru hole pcb mount pins to cut down on the board size because i cant see any constant use application for it so once in a while, coin cells should last just fine and they re cheap anyway
comodore (author)  raykholo6 years ago
Well, yea... Hack it, make it with coin cells and post some pics...
sounds good 1 more question about the power source though: did u use a 9 volt battery because the fototransistor creates a lot of resistance, even when the tv remote is on? if so that changes my design a bit as i originally was gonna use 2*1.5 v coin cells so 3v instead of 9v
comodore (author)  raykholo6 years ago
I also used a resistor to limit the current as you can see... I am not shore how much the phototransistor resists... I think that 3V is way way to low.... Experiment a bit.... ;D
k then ur idea of using a 9v battery was a pretty good one...
i could add a ferrite to the circuit like in the joule thief, but that would drain the batteries too quickly
i think that the best idea is to use a small 5 pin step up transformer with a 4.5v power source being 3* AG13 batteries, then wired into the rest of the circuit

As before, i want to use as little perfboard as possible so im thing about cutting out a small strip with the circuit on one side and contacts for all 3 coin cells on the bottom like this
that way they are all together and dont need separate holders for each one
comodore (author)  raykholo6 years ago
All this sounds like a very good plan to me! Is there an intention why you are improving this? What is the reason??? :D
thanks and as for the improvements, its basically the way i work with electronics: i find something really basic and then i try to take it a step farther... but more importantly im kinda cheap and green now that we have the environment stuff... so i just didnt want to see 2 AA batteries and some perfboard go to waste
comodore (author)  raykholo6 years ago
... Thats not a bad job...hacking Do you have your own inventions, so to say??? :D
course i do :) i have designed a load of stuff, but they are just ideas and designs that involve electronics but i dont know that much much about the finishing touches that go on to them so at the moment i just work on designing my many ideas, suggestions on this site, and some more basic building with electronics so its more like electronics theory 101 :)
comodore (author)  raykholo6 years ago
hehe... Do you know how to program a microcontroler?
once again , in theory i know how to use programmers, set up avr ghetto enviroment, basics on ladyada's usbtinyisp programmer... but i just havent done any of it in real life.... still if i i got all the stuff i would easily be able to work with it...
comodore (author)  raykholo6 years ago
...I am trying to program an Arduino do do something for me and I can't seem to get it..how should i write the code... I am trying to make it turn on a motor for a certain period of time(5 seconds) when the light sensor is triggered and that turn on the motor again but in the oposite direction when the light sensor doesn't get any light... Could you help me write the code? Thanks!
i have not actually worked with the arduino , but i can point you in the right direction.
i see that you are trying to make a sort of light seeking robot
now here are links to the language library, and another guide
thats the best i can do right now, but if i had the components i could probably breadboard this project with some ease..
i also advise that u use 2 motors so the code would do as follows:

go forward until until light sensor is less than <threshold>
then turn (1 motor forward, 1 motor back) until the light sensor is greater than threshold...
and have it repeat that whole statement

sorry but thats all i can do without the actual robot stuff in front of me...
comodore (author)  raykholo6 years ago
I am not making a light seeking robot, not even close... and i has to use only one motor... Thank you for the guides! Thanks!
well thats what i would have done if i had those components.... As for the guides, no prob and good luck btw, what are u making?
comodore (author)  raykholo6 years ago
Its a kind of a secret... I hope I will get it done and than every one can see! :D
XOIIO6 years ago
I'm going to make a smaller one, with a 110 ohm resistor and a 220 ohm resistor, and a toggle switch. That should work, right?
comodore (author)  XOIIO6 years ago
Yup... Is it done? :D
XOIIO comodore6 years ago
Yeah, it's done. I'll add some more suff, and post it as a slideshow when im done.
comodore (author)  XOIIO6 years ago
ok... Send me a message when you post the slideshow...
XOIIO6 years ago
Ant by the way, its not a transistor, its an LED. Transistors have 3 "legs".
XOIIO XOIIO6 years ago
Oh, thanks. The packaging says an led.
comodore (author)  XOIIO6 years ago
What packaging?
comodore (author)  XOIIO6 years ago
Its a Phototransistor... I don't need any teaching lessons... If you use an LED it won't work... because there is a very very big diference between an LED an a Phototransistor... Because the look very much alike that doesn't mean that they are the same!
Answer one of the following: What size solder board is this? What radio shack number? How many holes?
comodore (author)  stefannasehi6 years ago
Don't know, doesn't matter ; Don't know ; Again don't know and doesn't matter
froggyman6 years ago
why bother making this when you can just use a camera to test the remote?
comodore (author)  froggyman6 years ago
... Read some comments below... lame people say that... and I give them the same answer...
farhan776 years ago
that was a neat instructable! what i was wondering, was that what is the range of this phototransistor? what i had in mind was to hook up a small low voltage relay instead of using an LED. With this simple circuit i can use relay where i want a PUSH Switch kinda functionality. But that depends on the range of the circuit! any idea how long with this fototransistor will detect a general remote control beam(signals, pulses) :)
comodore (author)  farhan776 years ago
Well depends... 1. On the type, quantity and quality of the phototransistor 2. And the the same thing goes to IR LEDs You can make this with lets say 3 Phototransistors and make a simple push button circuit that powers up 4 IR LEDs... You can make something like my Film Canister LED Flashlight, just insted of the white LEDs you put IR LEDs... I think that would work, I am not shore on witch distance, I would say about maybe 2-2,5 meters, maybe... If you decide to make one of these, I would be glad to help you! Please feel free to ask questions if you have any! Cheers!
I just showed this instructable to my wife. . .she says that this instructable has dual features. . .worrying about a night vision camera installed in a room or office makes this instructable a paranoia detector! lol She just doesn't understand that there those out to get us!
comodore (author)  Infinity Plus One6 years ago
Hahahaha! Well, in the end it just detects IR signals weather from a camera or from something else... :D Say hay to your wife for me! :)
yah. but this costs, what, 5 bucks? also, you can add a buzzer to wake you up if someone is in your room with NV camera!
comodore (author)  kikkoman6 years ago
All together I think it cost less than $5... Yea.. a good idea, about the spying... :D
daomn, im using this for a little cart for my friends birthday and the motors are expensive! like 5 bucks a peice.
comodore (author)  kikkoman6 years ago
Well, depends what kinds of motors, try browsing the internet for more information... :)
just asking...if that possible to build an infra-red transmitter and receiver circuit that would be installed along the corridor,so whenever somebody passes through it, the light will turn ON.?
laser tripwire sounds more effective here infrared laser cost around $ 700 from what i know so it sounds better to use the cheapo pointer see other instructables for how to do this with an arduino...
comodore (author)  raykholo6 years ago
Agreed but on shorter distances it can be achived with IR LEDs...
right... both seem to be good ideas and yours is probably cheaper to do, but a laser is more effective and can be used over longer distances...
what about motion sensor device?
comodore (author)  jaksapendamai6 years ago
What about them? :D
what about it? its a proximity sensor... it cant transmit data like ir and laser can and its a lot more expensive + bigger
comodore (author)  raykholo6 years ago
Yea.... :D
comodore (author)  jaksapendamai6 years ago
Well, teoretically... Yes, but you would need a very good receiver and a bunch of IR diodes... It is better to just use a laser and when it is tripped it turns on the light...
sotsirh1946 years ago
How do you use the 3 pin 38khz infrared receiver. Does the output pin use a digital signal when ir light is detected or does it use an analog voltage?
comodore (author)  sotsirh1946 years ago
I had people who bought Phototransistors with 3 pins and witch 2 pins you need varies from the model, you just need to experiment and determinate... You can easely assemble this project on a proto board and that experiment with out the need to de-solder and re-solder... Hope I helped you a bit... How do you mean digital or analog??? If you have any more questions feel free to ask!
I made a similar circuit using a IR transmitter/receiver pair to make a detector to see if someone was in our driveway
comodore (author)  The_Vinninator6 years ago
Yea, like a detector and when the beam is broken the alarm or what ever goes off, right? This is a pretty simple project that is easy to build...
so, basically I can build this and point an IR LED at it and it will switch the circuit on? and will it stay on after I turn off the IR LED? thx
comodore (author)  oldanvilyoungsmith6 years ago
yes. But it will not stay on when you switch off the IR LED, it stays on while the IR is on.
gotcha, thx
comodore (author)  oldanvilyoungsmith6 years ago
np. :D Glad i could answer...
amando966 years ago
yea anytime, anyways do you know where i can find an LDR? i dont know any radio shacks in this country... -.- i will TRY to make this IR detector, will help to see if the phone is working properly, and it's simple :) hmmm i wonder How to make it catch IR signals from a greater distance hmmm...
comodore (author)  amando966 years ago
Well, it depends from country to country buy i get mine stuff at my local electronic store, they sell all of the components I need, well most of them. I really don't know how to make a device that catches IR signals from grater distances. Ask Goodhart, he probably knows, he is very very good at electronics! hope it helps, when you make your device, upload some pics or make an Instructables so everyone can see! Thanks! -Stanislav
of course i will :) i didnt make 'tuctables at first coz i just had a camera-phone so now i think i'll put more each month :) theres a repair man in town, he fixes VCR's, TV's, he probs has a suplier, i might ask him for stuff...
comodore (author)  amando966 years ago
Yea, ask him. i was surprised when i started working whit electronic the the store that sells suples was just around the corner basically! :D
lol thats just luck! i wish... lol
comodore (author)  amando966 years ago
Where do you live??? :)
portugal, near spain... But we are NOT spanish lol you?
comodore (author)  amando966 years ago
I know where Portugal is, don't insult my intelligence! :P I live in Serbia. Do you know where that is? :D
somewhere near hungary? i know portugal once lost a football match to serbia... lol i think...
comodore (author)  amando966 years ago
yea, it is right under Hungary. I'm not shore about the football match, I don't watch sports... :D
amando966 years ago
simple and efective, cant believe some peeps buy these for 7$ at the shop... when it costs like 1$ to make HAHAHA
comodore (author)  amando966 years ago
Thanks! I never saw a IR detector for 7$, pff :P Well, they are probably more sufisticated, the have an IR filter and can probably catch IR signals from a loner distance, but still, this is the simplest it gets! :D Thanks amando96! :D
imakethings6 years ago
does the fototransistor lights up or the led?
comodore (author)  imakethings6 years ago
The LED.
Guy.Fawkes6 years ago
Radio Shack in the US sells Or used to sell) a small plastic strip with an IR-sensitive stripe that glows in visible light when struck by the IR beam. Much simpler, if you just want to see if your remotes are working.
comodore (author)  Guy.Fawkes6 years ago
Agreed :)
DYLEGO comodore6 years ago
hey, does the phototransistor act like a switch? like when it senses IR light, does it close the circuit, turning on the led? if so, there could be a way to rig this to be a remote control car with no steering! i could mod the beetlebot with a simple phototransistor and make a ir remote!
comodore (author)  DYLEGO6 years ago
well, yes, it acts like a switch.... When it senses IR light it closes the circuit makeing the LED turn on. I guess you could use it for a battle bot or something.
DYLEGO comodore6 years ago
the problem is i can only turn 1 motor on and off unless there is a phototransistor that senses one color of ir light. there will be interference if i do 2 or more... still a good idea
comodore (author)  DYLEGO6 years ago
i dont think there are different colours of IR light...
DYLEGO comodore6 years ago
yeah theres probably like a 0.0000000000000000000000001% chance!
comodore (author)  DYLEGO6 years ago
Actually, IR has "colors" just like visible light does (e.g., different frequencies). It's unlikely you'd find PTs that have a narrow frequency response, however; it's much easier to use digital pulse modulation to distinguish one command from another. Of course, you'd then need an encoder at the control end, and a decoder at the receiving end, making the whole project much more complex.
comodore (author)  Guy.Fawkes6 years ago
That is very very interesting... I remember wanting to make something that would go in then i light up IR LEDs... I think i ment to use the phototransistor... Could this whole thing be done whit an Arduino?
neardood7 years ago
Just a bit of advice, use the spell check option, cause reading that many unintentional mistakes on one page gets annoying
DYLEGO neardood6 years ago
al i c is 3 speling mestakes adn teh fototransistor mestakes sorry i had to so that!
comodore (author)  DYLEGO6 years ago
My native language is not English so....
DYLEGO DYLEGO6 years ago
had to DO that
comodore (author)  DYLEGO6 years ago
My native language is not English soo...
munchman DYLEGO6 years ago
Yeah, you kind of went back on yourself with that one.
Zideeane6 years ago
Nice and Basic
comodore (author)  Zideeane6 years ago
Thanks, Dr Octoganapus, BlahhhhhHhHhhHHHhhHh! xD
collard417 years ago
this is a better version, although it is harder
ir detector.jpg
I dont understand it whats RV1 and D1 and Q1? Its just me because i just joined and everything
RV1 is used to bias the transistor, essentially you can use this to 'match' (for want of a better term) the CDS (D1, light sensitive resistor, used to detect the IR, but will also detect ambient light) and/or set the sensitivity of the device. Q1 is a NPN transistor that should be working in its 'active region' (google is your friend here). Essentially based on the ammount of light hitting the D1, Q1 will pass an ammount of current making the light come on.
comodore (author)  ReCreate6 years ago
You can learn more about electronics from the electronic club or form a book, Electronics for dummies...
"Electronics for dummies" Eh that's ...Funny...*walks away*
comodore (author)  ReCreate6 years ago
It's a very well written book! Helped me a lot! It's one of the books from the Dummies seriese!
yeah i know
comodore (author)  ReCreate6 years ago
ok, just trying to help. :P
RV1 is a potentiomenter, or you could call it a variable resistor. it makes it more or less sensitive. D1 is a photodiode. this detects the light Q1 is a transistor (PNP) and this in effect amplifies the signal. it is connected between RV1 and D1 as this is known as a potential divider. depending on the resistance of RV1 and D1 the voltage changes between the two, then turning the light on. actually i found that it is better to have a 'Darlington Pair' which is like above but the lamp is on Q2 and Q1's collector (top) is connected to +12V and its emmiter is connected to the base of Q2. will post a new one later with this in
Oh I understood the first half but at the middle you got me confused.
the_doctor6 years ago
What kind of LED did you use? and does the color count because i just tried to make one today and it didnt work right and you didnt mark the polarity on the batary does the tansisor atach to the posative or negative side?
comodore (author)  the_doctor6 years ago
The resistor attaches to the negative side! black=negative red=positive <br/>I used a standard red 5mm LED, i think it runs on 1,5 V, don't use white or blue!<br/>
haha ok thanks its just you have the batary backwards on thier... or up side down ... i think
comodore (author)  the_doctor6 years ago
Well, see the schematic again it explanes! Did you build it? Post some pictures of your creation!
yeah i finished it all i had t do was flip the polaraty of the parts =p
comodore (author)  the_doctor6 years ago
haha, I am glad it works, congrats! Post some pictures... :)
Hi comodore this is my phototransistor that i talked about... it has 3 pins. and when i test it with multimeter (Continuous) it doesn make any sound and didn't react with my tv remotes
OK I finally get it work!!! Thanks a lot man !!! =p I tested it with a led instead of multimeter. I think the power is sufficient (Or something like that) to sound up my multimeter... i don't know... Both of them work if u point it direct to the ir source (Like using a flashlight). The black one is more tolerate in working angle (About 45 deg), but the cylindrical one can work more far from the ir source.
comodore (author)  digital_fortress6 years ago
Cool! I am very glad you got it to work! Have fun whit it! ooo And post some pictures of you creation here, so the others and me can see!
comodore (author)  digital_fortress6 years ago
OK, I suggest you start whit the clear one, NOT the black one! Use the one that has like a cap, and a optic. Here is what I suggest you do. Build the circuit on a protoboard!!! And just try to get the right combination of the pins. Make the circuit, just whit out the switch. Solder 3 wires to the pins and star making combinations. You will eventually find the right one! Feel free to ask more question if you have!
Here is how to repair your faulty remote controls:repair remote
comodore (author)  pellepeloton6 years ago
Please don't spam!
I would not call this spamming. My link is related to your idea. Once one has build your IR detector and has found out that their remote is indeed faulty, then they need to know how to repair remote controls! Do ypu still call this spamming.?
comodore (author)  pellepeloton6 years ago
Well, so if I put up a link on your Instructable regarding my IR detector, you would agree, right, they are related as you sad.
In what range does this detect?
comodore (author)  Lithium Rain6 years ago
Well, it depends on how many Phototransistors you put, whit 1 not very far... But it allso depends on how many IR LEDs there are and what is their intensity...
A night camera puts out more IR light than a remote control...
Oh, sorry, I should have phrased it differently, I meant, "this will detect devices transmitting in the range of __ to __ mhz?"
comodore (author)  Lithium Rain6 years ago
OOOooOO, no problem, honestly, I don't know. sorry I'll try to find out!
Okay, thank you.
joelpinto907 years ago
y take so many pains??/ just switch on your cell phones camera n put the remote in front o it in press buttons and it wud show a purplish light like the first image in the 7th step!! works on my N70!! Thnx....
I guess the answer to that is the same as the answer to: why build anything when you can go out and buy it easier?

comodore (author)  Goodhart6 years ago
That is not fun, at least we at instructables like to make thinks... :)
That was my point :-) The answer to Joe's question is the same one that keeps us making things :-) We do it to learn, for the fun of it, and um, to learn LOL
comodore (author)  Goodhart6 years ago
yea, my point exsacly...
some cams have ir block filters
yes they do but they don't block it all. if there is an ir filter you will see a faint reddish purple glow where the led is. if there is no ir filter the remote will light things up 3 to 5 feet away
oh ok
But it will be better that you make your own. It makes you feel proud!
comodore (author)  joelpinto907 years ago
If you ask me this is more interesting. A nice simple project.
Whatnot7 years ago
Two little remarks, first I think the more correct term is near-infra-red that's used in remotes, and second, I can see the light of many remotes if I look at it closely in the dark, it looks like a faint amber that pulsates, but it is visible to the naked eye no matter what textbooks say. The real infra-red you obviously can't see because it's absorbed by the liquid in your eye and if your receptors had sensitivity to it the heat of your body would constantly oversaturate them I guess.
kadris3 Whatnot6 years ago
a caution here. no one should be looking at IR or UV light directly. it will injure your eyes. if u can see the emitter on a remote enjoy your gift. you would be an invaluable asset to the marines or navy. this is an unusual gift. good for you.
soad22 Whatnot7 years ago
comodore (author)  Whatnot7 years ago
Cool! Do you study biology??? :)
neardood7 years ago
that poor indicator LED looks a bit strained, maby you should add a more powerful resistor??? If not, the LED will eventualy die, as it is when u leave it on it'l get hot.
if the battery were new and the forward voltage of the IR LED is 1.2vdc then 390 ohms is needed. with the battery @ about 7.2vdc the 300 ohms is the correct figure. simple circuit that works: good instructable
comodore (author)  neardood7 years ago
Actually the 9V battery is almost dead so that is the reason why the LED is faid.
S1L3N7 SWAT6 years ago
I have a bunch if IR LED's and I know some of them are IR receivers, but I cant tell which are. Is there a way I can check? Could I run a current through one and then shine some IR light into it and check it on a volt meter to see if it changes or something?
comodore (author)  S1L3N7 SWAT6 years ago
Well, you can assemble this circuit on a proto-board(picture below) so you don't need to solder and you can easily replace IR LED and see witch one is an IR LED and witch one is an IR receiver. Just take any remote and press any button aiming at the IR LED/receiver, and if the LED in the circuit blinks that means that you have connected an IR receiver. If you have any more question, please feel free to ask, you can post question on my orange board. Good luck!
Yeah, that's what I've been doing. Maybe I'm not building the circuit correctly. Thanks anyway.
comodore (author)  S1L3N7 SWAT6 years ago
No problem, just go and buy one phototransistor and than you can check what is an IR LED and what a phototransistor.
geeklord6 years ago
could a get a fototransistor out of an dish receiver box?
comodore (author)  geeklord6 years ago
I am not shore.
sitmex7 years ago
Hey, nice project, but I've learn a simpler solution: use your digital camera or your cell phone camera to check if IR is been flashed, turn your camera on, and point it at the lens and check the screen. If present, IR light will be visible. on your camera screen.
comodore (author)  sitmex7 years ago
Yes, I know as you may see (picture 3). I agree, taking your camera is more easier than making this, but this is the more interesting and fun way! Instead of the LED you can put an electric motor and the motor will turn off and on to the rythm of the IR pulse, you can have more fun whit this.
Hook up a speaker and start a band.
that made me laugh...:D
comodore (author)  YummyPancakes7 years ago
You get a metronome! COOL! :)
yes i agree lol
comodore (author)  neardood7 years ago
do you haft to use that exact resistor or will some thing close work
comodore (author)  mayan guitarist7 years ago
Well, it is best to use the resistor described in the Instructables, but if it is something really close it should work! Try assembling the circuit on a proto-board so you don't have to desolder if it doesn't work.
ok thanks
This works !!! i just made 1. . . but my phototransistor had 3 pins not 2 like in the instructable.
What Pins did you use?
i used the middle pin and the 1 on the flat side of the phototransistor
comodore (author)  Awesomenessguy7 years ago
Congratulations! 3 pins, that is uncommon and audd!
the 3 pin ones have a built in amplifier, and i think a demodulator.so it shouldnt work, unless you have a special chip for it. if you get a IR transmitter and then use it as a transmitter it should work.
when i sine my 5mw 650 wavelength (red) laser in to the phototransistor the LED lights up
Nicrostar7 years ago
Can this be done on a breadboard? PLEASE REPLY
comodore (author)  Nicrostar7 years ago
I always reply! :) Yes, allmost any electronic project, actually all electronic projects can be made on a breadboard!
ok thanks
comodore (author)  Nicrostar7 years ago
No problem, if you have more questions feel free to ask me, on my orageboard or anywhere else!
RGM La Paz7 years ago
so this can control your tv sorry its that im a curious year old and i just started learning this cool stuff
comodore (author)  RGM La Paz7 years ago
What? No. This can detect IR Light, that comes from any remote. It can't be used as a remote. If you have any more questions plase feel free to ask.
bosherston7 years ago
Great Instructable, simple and effective, one small point... you mention power on/off in step 7 and prob' should read on/standby, ok I feel twattish for saying that, but I got it off my chest. Switch your appliances off at the wall when you've finished using them, argh there I go again..
comodore (author)  bosherston7 years ago
Thanks! LOL
neardood7 years ago
the IR sensor looks like a IR emitting LED
comodore (author)  neardood7 years ago
No, its an IR sensor. I looks like an emitter though.
coolketan957 years ago
Thats a great Instructable. Thanks 4 it
comodore (author)  coolketan957 years ago
Thank you!
coolketan957 years ago
I also have the same DVD player remote Cheers
comodore (author)  coolketan957 years ago
Cheers! :)
OMG its working!!! I just made my first electronic project ever and its working!!! YAY! Thanx for this =D Very useful =D
comodore (author)  railpressureflip7 years ago
I am happy to hear that!!! If you have time upload some pictures so every one can see! Thank you!
collard417 years ago
i did this and it doesnt work. it is just too simple and the Photo transistor it not nearly sensitive enough. you need to use an op amp to amplify the signal. it is much more complex. i will post the circuit later as i do not have time.
comodore (author)  collard417 years ago
IT WORKS!!! I did this and it works, you need a more sensitive phototransistor!!!
you can use a phototransistor that has an amplifier, but they also have de-modulator that is basally a decoder. the de-modulator is not compatible with everything so I found that you have to use an amplifier. anyway, how do I know that you are not wiring the LED directly and the circuit is not actually doing anything.
comodore (author)  collard417 years ago
well, on that you just have to trust me.
collard417 years ago
would anyone like me to create an instructable on how to make a toy shootout game. an infra-red gun that when aimed at the target makes a light go off or whatever you want. (i have made a solenoid shoot a can off a bench.)
Localghost7 years ago
would it be possible to use a LDR for this , and using a piece of negative ' fully exposed' photographic film to filter most of the light (they let IR through), Also, a LED can be used as a light detector if connected "other way round", then an emitter will act as a reciever, not a very good one, but it will still do it..
pooandwee7 years ago
well heres my instructible to do exactly the same thing. get your mobile phone camera, point the remote at the camera and press a button, if you see it light up on your mobile screen then it works. no neew to build any of this.
comodore (author)  pooandwee7 years ago
This Is an IR switch and a detector. Yes, you can take a camera an point it and see the IR light but this is a more interesting way. If you read some of the other comments, you would have saw that other people suggested the same thing.
el_dark7 years ago
which IR Transmitter would be the most powerful between those 3? would it be the blue-ish one?
comodore (author)  el_dark7 years ago
I am not shore, I just used the one that they had in the store.
el_dark7 years ago
if you take a camera without IR filter you can see the IR light as if it was a white led, it's quite something ;)
dunnos7 years ago
so basicly a phototransistor would shut the circuit? would an ir receiver from an old roller ball mouse work for this?
gdshardy7 years ago
Comodore...Most excellent Instructable for whetting folks appetite for some IR knowledge! Thanks much!
comodore (author)  gdshardy7 years ago
Thank you! Don't forget to rate! :)
larch467 years ago
Dropping in on all of the conversation...I picked up on the Infra Red while scanning through all of the Instructablles. I recently returned from a trip to San Antonio, TX and my Son-In-Law asked me to come out onto his porch to see a Gecko. I took one look (it was night time) and then ran inside to pick up my new Sony Digital Camera. When I returned (within a minute), the Gecko was gone! I pointed my camera in the direction of the last sighting and just lightly touched the shutter button.. I was really surprised to see a big RED light flash onto that spot. I continued looking for the Gecko with this Infra Red light to no avail...the little bugger hid himself really well. However, I learned that my camera can be used for searching in the dark, which was really COOL... Just thought I'd put in my two cents worth of info...
comodore (author)  larch467 years ago
Cool story! Did you take a picture of the red light?
Comodore: The Red Light was part of the range finder on my camera. The only way to take a picture of that (and it could be done) is to use another camera while I am using this Infra Red light to search in the night... Larch46
thepaul937 years ago
you could just use a digital camera, the digi cams pick up the ir lights really well. just point to the lens and look at the lcd display.
comodore (author)  thepaul937 years ago
Yes I know, everybody says that, and I know!!! To me, building this simple gadget is more fun than taking a camera.
bladdo7 years ago
Hey, do you know where I could get a phototransistor that works for this? :X I bought one on mouser and I tried this and it didn't work :'(


Thats the one I used, I also tried a bunch of other IR lights I had laying around which looked similar to the one you used in the guide and nothing worked :(

Do you know of a phototransisor that would work for this I could buy on mouser?
bladdo bladdo7 years ago
Hmmm Thanks, I wish I had gotten the right thing before hand cause now I'm gonna have to wait until I make a big mouser order again to finish this :P (shipping is expensive!).... Also how could I power this on two AAs or AAAs..... Would I need a different resistor?
comodore (author)  bladdo7 years ago
I used a 9V battery as you can see. I am not shore about the two AA or AAA battery, you will probably need a resistor if a different value.
see below. IR leds are very LOW voltage. u still need 30 to 47 ohms w 2 leds in series on 3vdc. X
bladdo comodore7 years ago
Could anyone of expertise chime in here?
*ahem* Let's see here... If you're using that little voltage, then you could probably just go without a resistor altogether. By looking at your pictures (on the Instructable), You are using a 1/2 cm LED. By experience, I know that those sizes can hold up to 3V. They can even go up to 5V. (3V is the voltage of 2 AA or AAA batteries-- 1.5 + 1.5 = 3V.)

I have been building robots for years, and I have been fiddling with electronics even longer.
kadris3 bladdo7 years ago
just a thought but a photodiode might work as well. the base connex isn't used so that gave me the idea. i meant to say earlier : nice simple schmatic. i'm building one.
comodore (author)  bladdo7 years ago
The one you bought,Infrared Phototransistors Ir Emitter Clear 940nm, as it says it is an EMITTER. You don't need an emitter, you need a RECEIVER . You bought one that emits light, that type of phototransistors is found in remotes and night vision gadgets. This one receives the IR light and can turn it into a electrical inpuls.
Any of the Phototransistor receivers will do!

If he has a transmitter, then he should point it at his TV and see what happens! LOL!
cvxdes7 years ago
So, if I got a 3v power supply, lost the switch, and hooked up a few IR LEDs instead, this would repeat my signal?
kadris3 cvxdes7 years ago
IR leds have a very low forward voltage. typically 1.2 vdc or lower. 3v would fry them. u could series 2 IR leds with 30 to 47 ohms across(series) to the line and it should work on 3vdc. now find a 20 to 30 ma relay and put its coil in the line of the above detector. now u can trigger an alarm that no one can see. would work well fr doorways, or as a sensor to activate a signal on electric trains
Hey its even easier to see if your remote is working, by simply taking your digital camera, point the remote at it, and look at the screen. If your remote works, you will see the IR light on your camera screen. If you dont see the IR light on your screen, replace the batteries in your remote...
Yes, but that would get rid of the fun of building a small electronic gadget. Who wants to miss out on that?
comodore (author)  YummyPancakes7 years ago
My point exactly!!! LOL :)
LeumasYrrep7 years ago
Nice and simple. Wow didn't know cameras can see IR. But why is it blueish purple? shoulden't it be red?
comodore (author)  LeumasYrrep7 years ago
Thank you. Good question! I hope some one who knows, sees this question! I really have no clue. :)
Well Hmm... Probably has something to do with the filter (the thing that makes it show up, and also protects the sensitive camera from "powerful" light).
tiotion7 years ago
Great instructable! Whats the range on one of these?
The schematic used here shows a toggle switch but the one in the instructable is a push to make switch, im just saying.
comodore (author)  lifelong-newbie7 years ago
Yes, you are right! Thank you. I just didn't have the time to fix it.
it was just me pulling hairs, otherwise it's a good project and a nice starter in IR for budding studiers or electronics
comodore (author)  lifelong-newbie7 years ago
Thank you.
How do you work with the electronic board. Do you have to etch it at all? Or do you just solder a wire from one hole to the other? I really want to get into proto-boarding or whatever it's called. Any help would be great. Thanks
comodore (author)  electronicfreak227 years ago
Well, I don't know much, I will tell you all I know.

There are two main types of board, lines and dots. Lines are when one whole row is connected, dots aren't connected, you just have copper dots so the solder will stick. In this instructable I used a dot board, I just use dot board. You stick you component trough the wholes in the board and solder it. Look at step 5 in this instructable for some pictures. I connect it whit wires or if the components are close you can bend the components wire and connect it.
To test the circuit I suggest you buy an electronic proto board, ones that you don't have to solder. I also suggest you buy a book called electronic for dummies. The book is grate, every thing is described in rich detail and understandable to a beginer in the interesting field of electronic. Thank you, and don't forget to rate! :) If you have more questions pleace feel free to ask them!!! :)
Lol I have a Proto board AND Electronics for Dummies, no joke. Thanks +1
Jordo7 years ago
So this could kinda be used as an IR switch, right? you could wire this where an existing switch was and then point your tv remote at the IR detector and it would turn on.
comodore (author)  Jordo7 years ago
Well, yes and no. You could power something else, maybe a small electric motor. You just wire the motor where the LED is in this Instructable, the motor will turn on and off to the rythm of the pulse that the remote sends,in this case the IR detector is a reserver. I am not shore I understood you well, if you have more questions place ask me!
velladraco7 years ago
Hey, thanks for the timely instructable! My TV finally died after many years and repairs- my hand slipped during the last repair of an intermittent circuit problem allowing the metal edge of the igloo dryer I was using to warm a circuit after freezing to touch the tuner casing for a split second...POP--FZZZZT!!! Oh well, it had a long life. Have you ever seen a circuit completely dissect out of a printed circuit board?...Really funny-laughed till I cried. This left me with my shop TV-a curb rescue with no remote, a permanently displayed channel indicator, and a dead??? IR reciever. Just happen to have all the bits except the fototransistor so I'll make one of these babies and, with the help of universal remote, know whether to repair, replace, or forget it. Thanks!!Oh-advice to others who troubleshoot their own stuff--igloos are great since they blow warm and slow-duplicating the normal warming of a circuit nicely-but from now on I'll insulate the nozzle with a bit of tool dip or rubber sheeting-it wouldn't be very funny if this had been an expensive new piece of equipment.
comodore (author)  velladraco7 years ago
Thank you! This is a good thing to have lying around the house because if you know a little bit of electronic, curiosity will make you open the TV and find the problem your self.Before you open the big TV it is good to check if the problem is in the remote. Thanks for uploading the photo! If the TV reciever and the remote work you can make a lot of cool remote controlled stuff!
Faber7 years ago
If you don't have 9V batteries, you could use 2AAs or AAAs with the proper battery clip and a smaller resistor. Yes, it is a great idea! I'm going to build it when I get the chance!
comodore (author)  Faber7 years ago
I just used a 9V battery because I only had it. Thank you!
In the radio and TV shack we had always used the IR card. It's about the size of a credit card and when you flash the remote at the card, you can see the IR light on the card. Overall a very informative and great project for us to homebrew, Yea Baby!
Sgt.Waffles7 years ago
Holy cow, you CAN see IR light with a cell phone. AWESOME!. Maybe its possible to make a phone into a nightvision seeing device with IR LEDs...........
There are surveillance cameras with built in IR LED:s which enables them to see in complete darkness. The camera in a cell phone and many cheap cameras are of the exact same type. So yeah, if you use a powerful IR-torch with your cell phone you could see in complete darkness.
Now here bears the question. Where am I going to find a powerful IR-torch.
I'm not sure where you can buy one but apparently you can make one if you have the parts.

static7 years ago
Good instrustructable. I have to believe it would operate with 3 V. as well. I can see myself using a small dead remote as a case for the project. I understood I could use my digital cameras to view the output of an IR LED, but never tried doing do until today. The following is a vid of a properly working remote.
comodore (author)  static7 years ago
Thank you!
Xellers7 years ago
This is a great instructable, but you can detect IR light with most digital cameras. Instead of building this circuit, you could just look at your remote with your digital camera.
comodore (author)  Xellers7 years ago
Yes, I know, but this is a more interesting way, don't you agree? :)
Yes, I must admit that I do agree. One good use for this would be to combine it with Kipkay's phaser alarm clock killer to make it wireless. By making the phaser simply turn on an IR LED and by hooking up the alarm clock's switch to your device, it would be possible to make it wireless. something I will investigate...
comodore (author)  Xellers7 years ago
Cool idea!!! You could send a private message to kipkay regarding your idea, the wireless phaser alarm clock killer. God luck! :)
drewdoog7 years ago
nice instruct. i made a very similar device awhile back, and want to comment on some posts. #1. The distance on this is under 10". I have a pretty powerful 6 emitter remote and this is my experience #2. next, this has no filter, so anything that give off ir (the sun for example) would be detected. #3. You could increase the length of this by wiring in an opamp circuit. that would magnify the signal received and you could easily get 10+ feet off of it. #4. this could be used to control things if you would add a relay to it. You would still have an issue with #1 and 2
comodore (author)  drewdoog7 years ago
What kind of filter? Yes, I know the sun gives off IR but how can a filter separate IR that sun gives off and IR that a TV remote gives off?
its an electronic filter that only takes in certain frequencies. things like the sun give off a low frequency ir, remotes user higher frequencies, with a filter, it would block low ir.
comodore (author)  drewdoog7 years ago
Ooo, cool, Thank you!
comodore (author) 7 years ago
Thank you!!! There is a picture in step 8, IR light.
Great idea dude, you can also check if your remote is working by pressing a button and pointing it towards the lens of a digital camera and looking through the viewfinder, the lens on digital cameras can see IR light
Phoghat7 years ago
Anyone have a link to make or buy (yuck) a LEARNING remote (one where you can teach the remote proper IR codes from an existing remote)?
On perf board, does it really matter where you solder the stuff to, or can it be anywhere?
comodore (author)  GorillazMiko7 years ago
Like Itsgoofytime said it doesn't mater. I made it like this so the 9V battery will fit.
In this circuit, you can solder it anywhere, just make sure they connect correctly.
This looks like a cool Instructable! :-)
comodore (author)  chrisrock4107 years ago
Thank you!
cprocjr7 years ago
with is spelled with not whit, but great instructable. i think i might try this.
comodore (author)  cprocjr7 years ago
ups, Thank you. It is spelled correct now. :)
Hold your controler up to a am radio(turned on), should make sound when buttons are pushed.
Charger_067 years ago
Could you use this as a power switch?
Brennn107 years ago
Wow, this can definitely come in handy! It does get annoying when you don't know which one is broken.
comodore (author)  Brennn107 years ago
Thank you!
mrmath7 years ago
What kind of distance can this thing work over? If you need to hold it right next to the remote, or IR source, it wouldn't be very useful for finding IR based spy devices.
comodore (author)  mrmath7 years ago
It depends on the intensity of the IR signal. IR based spy devices have very strong IR emitting signals, because you need a strong IR signal to see in the dark,plus there are at least 5 IR LEDs so the signal is much stronger . I am just guessing but I would say that you can catch a strong signal about 1,5m-2m away. Go to step 7, a lot is explained there. Good question, in my school we have IR cameras. I will take my detector and see at what distance can I catch the signal. I will gate back to you! Thank you for posting a comment! Don't forget to rate it! :)
hammerhead7 years ago
You can also use most digital cameras and camera phones to see infrared light. I had much use of it when I worked with televisions and such; the first thing I did when the remote did nothing I pointed my camera phone at it to see if it worked. Nice instructable! It shows a simple device that could be very useful in certain circumstances.
comodore (author)  hammerhead7 years ago
Thank you!
Cool! This Instructable used that board thing stuff. I need to get some more, I might skate over to RadioShack later to get some. Nice job!
comodore (author)  GorillazMiko7 years ago
Thank you!