Infrared detector Pen.

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Janitor Tzap
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Joined: Sat Aug 12, 2006 5:17 pm

Infrared detector Pen.

Post by Janitor Tzap » Wed Aug 25, 2010 7:35 pm

Hi all,

Some one was asking for a way to check remote controls some time ago.
And I remembered this Infrared detector Pen I made.
The original design came from a March 1993 Electronics Now article.
But I wanted mine to be more easy to carry.

Before you go and ask where the 470 ohm resistor is for the LED.
I left it out because of the tight confines of the AAA Flash Light.
And since I'm not using the 9Vdc that the original circuit called for.
I was able to save some space on the Perforated PC Board.

Now you could do this in SMT much easier. :P

one problem that has come up is the fact that the watch batteries I used for this project.
Are not as easy to come by as they once were, and are not cheap.

So if your going to build your own.
I suggest going with an AA Pen Light, and using AG-13 Watch Batteries.
Which are relatively easy to find, and fairly cheap too.

Signed: Janitor Tzap

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Joined: Tue Mar 24, 2009 11:08 am

Re: Infrared detector Pen.

Post by jimmy101 » Thu Aug 26, 2010 2:53 pm

Or, just point the remote at a digital camera. The camera has no problem seeing the IR of the remote.

Or, connect just about any solid state light detector (phototransistor, photodiode...) across the mic input of a PC or laptop (maybe with a 1K-10K series resistor), fire up your favorite audio recording software (like Audacity) and record the remotes signal. An Audacity screen shot of a typical IR remote recorded this way is at (from the page at

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Re: Infrared detector Pen.

Post by jwax » Fri Aug 27, 2010 4:04 am

Or, a series circuit of a 9 volt battery, a phototransistor, a 390 ohm resistor, and any standard LED.

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