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Can I use an IR sensor as a normal switch? Answered

To clarify my question: I want to either order an IR sensor and IR led or scavenge them from a tv and remote.

Then I want to connect the IR led to a switch and a battery and the IR sensor I want to replace the normal push switch in a flashlight. So that I could remotely power on the lamp by pushing the switch and activating the IR led wich sends a signal to the IR sensor shuttipowering the lamp on.

Now my question is if this could be possibly without extra circuits or stuff just hooking them up like I said. I however fear that I'm going through matters a little to easy...

If not what should I add to the circuit to make it work?

I already did some research but it appears that no site really suggests such a project.. The best site I found is this one but that one doesn't really help either...



8 years ago

Your link to the sensor is only for the ir detector. It won't do much without some more parts.

If you only want it to be on when you push the control it would be much easier. In that case google "light detector circuit" and substitute your ir detector for the solar cell.


Answer 8 years ago

Yes I only need the light to be on when I push the button on my remote! When I release the button the light should go off again :)

So I can still use the IR Led then? And the solar cell wouldn't react to any other light in the room like natural sunlight?

Thank you both for replying. I'm somewhat skilled in electronics but this is going a little above my head I'm afraid...


Answer 8 years ago


You don't use the solar cell, you use the ir detector instead.

Jack A Lopez

8 years ago

I think the way to make this happen is to use an existing IR remote, together with a homemade, or kit-made, circuit that activates a relay (or other switch) upon detection of the presence of an IR signal.

Before actually explaining how such a thing works, I want to show you that such things exist, in kit form, here for example:

That particular retailer has like three or four kits that do something when you point an ordinary IR remote at them.  Probably none of them perform the exact action that you want for your application.  Moreover, there is probably someone else out there, on the internet, who has already explained how these circuits work, for free, and if found you could just copy their circuit, and/or modify it work for your purposes.

I am still searching for that ideal, easy to follow, example. Maybe someone should write an instructable on the subject.

The other thing I wanted to mention is that there is a reason why the designers of IR remote control went to all the trouble of modulating the IR light with this 40 KHz (or 38, or whatever it is) squarewave.  The reason they did this is because the detected IR signal, even over a distance of just a few meters, is very faint.  An IR LED does not produce much light power, and even less of that finds its way across the room to the receiver.
Thus an amplifier with large gain is needed on the receiving end, and confining the signal to a narrow "band"  helps the amplifier to distinguish the signal from the noise.

The good news is that someone has already done most of the engineering for you.  Old IR remotes can be found for almost free, and the detector modules can be obtained for just a few USD.

BTW, note that these IR detection modules are something different from a just plain IR photodiode or phototransistor.  The difference is that the module contains both a photosensor and  additional circuits needed to amplify and detect specifically the kind of signal produced by an IR remote.  Some example pictures:

IR modules (3 leads: +5 V, ground, signal out)

phototransistors( 2 leads, conductivity changes in response to IR light)

Also BTW, these links are just for reference purposes, if you actually want to buy an IR module, or kit, you should seek out someone who ships to where, in the world,  you live. Belgium? That's a long way from where I am.