How do I amplify an IR transmitter?

My friend has this really annoying neighbor who pretty much has the TV on all day at max volume and has been pissing everybody off for at least a year. Since he lives in a third world country the police won't even bother to intervene. I've offered my basic Arduino skills to see if I could put together something that could turn the volume down from a distance but need a little help.

First off, I bought a couple IR emitters at SparkFun (namely this, and this). Unfortunately with my own tests, this only worked at at maximum range of 2 or 3 meters and I need this to go up to 20-25m (the good thing is that I have direct vision of the stupid TV set).

Of course, finding the proper volume codes for that particular TV and creating the software to produce these is another battle that I'll save for a future post if I can't manage on my own.

Is there a circuit that I can use to amplify these LEDs? If not, will an IR LED array serve my purpose?


Firstly a lens will greatly extend the range of an IR emitter, as will pulsing it at 200mA or so.

Secondly TV-B-Gone: the code should have all the off codes for most makes....

Firstly a lens will greatly extend the range of an IR emitter

Is this something custom that I'd have to make myself or is this readily available somewhere?

pulsing it at 200mA

This sounds simple enough for me to try on my own. Thanks.

Regarding TV-B-Gone: That looks very promising and for what I can see in the schematic, they pretty much hook the IR LED straight to the battery through an NPN transistor. They also use a 10K resistor for the 4 LEDs in parallel. I'm not sure how to calculate how much current will flow through those LEDs though as I've never seen 4 LEDs in parallel use just one resistor. If you could help me figure this out I'd appreciate it.

If you could house an array of IR leds inside a a reflector to focus the beam you might have more luck..

Or you'd have to find a nice (watt range) IR led and focus it.

Failing that, hide the device and use a radio to activate it... but you'll be left with working out the tv codes to control the tv.


Bear in mind that shooting an infrared beam through glass can be hit-or-miss.

It might be easier to get a laser and melt the TV