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The TV Sniper

Controlling a TV from beyond the range of any normal remote control

What This Is

Universal remotes such as the TV-B-Gone ( ) or Ninja Remote ( ) serve a useful function - that of granting you power over surrounding television sets! (Update: I have been informed that The Ninja Remote is also known as a "TV Wizard" and usually available on Ebay very cheaply.)

The drawback is that these remotes only work within a relatively short range - enough to control a TV in the same room, but nothing more.

The TV Sniper is a simple method of extending the reach of your chosen TV control tool. It will focus and allow you to finely aim the infrared beam from your device, thus extending the range. No electronics needed - all you need to do is mate together some common items. (Actually there is also an electronic method, but that's at the end and only if you're interested.)

If I may say, I really like what I made with this project. It's elegantly simple and puts together things that would normally have nothing to do with one another - and the result is great. Intuitive to use and simple to implement.

Why This Is



I originally thought of this concept quite some time ago when I had some very noisy people in my neighborhood. I contemplated quiet means of irritating them in an opposite fashion. While they bothered me with overt loudness, I would bother them with covert silence. I could send the remote's signal from afar secretly to mute the audio, lower the volume, or flip the power on their TV at inopportune and puzzling moments. If I could see the TV through a window, I could transmit to it secretly from afar. Balance would be restored!



Happily, as it turns out I never did need to make or use it. But the idea stuck with me and I always wanted to see if it really would work. It did, and so here it is in the simplest working method I was able to make.

(As a side note, I tried several different methods of extending a TV remote - not all of them successful. One is worth mentioning, though. See the end of this page for details in the APPENDIX.)

Materials

You will need:

  • A remote control (TV-B-Gone or Ninja Remote/TV Wizard or similar)

  • A pair of binoculars

  • A small LED light (for practice and testing)





The binoculars I used are 10x50, which means they are 10x magnification and the objective lens is 50mm in diameter. I bought these for 15$ some time ago at a clearance place, and they really are awful binoculars - so don't think you need anything special. Your mileage may vary but these worked just fine for me.

The LED light is not much more than a bright white LED with a 3v coin cell on a keychain - more Dollar Store goodness. Pretty much any high-brightness LED light should be suitable.

What To Do

We will be shining the remote control THROUGH one side of the binoculars, while "sighting in" on the TV by looking through the other side of the binoculars.

This does two things: one, you use the binoculars' optics to PROJECT the IR from your remote (the reverse of the usual direction of operation of the optics). Second, you take advantage of the fact that both sides of the binoculars point at very nearly the same place to aim the projected IR by looking at the TV through one half of the binoculars, while you project the IR from the other half.

Practice makes perfect, and here's how to get the hang of it.

To practice, situate yourself some distance away from a blank wall in a dimmed room. Point your binoculars at the wall, and shine your LED light into one of the binocular eyepieces. Observe the light pattern projected onto the wall - it should be a smoothly lit circle. Experiment with distance between LED and eyepiece, but remember to keep the LED pointing STRAIGHT into the eyepiece! If it is crooked you will lose much light and the pattern projected will not be a nice circle.



(Bare LED light, contrasted with same LED light through binocular eyepiece)

Once you have the hang of that, try looking through the other eyepiece at a distant wall and shine the LED through the other eyepiece. You should be able to see the projected circle of light through the binoculars - note how the projected light is somewhat to the side of where you are looking. Note this and keep it in mind as a reference for when you are aiming with the invisible IR light from the remote later. Experiment with the distance between the LED and the lens and observe the results of the projected circle of light.

Now locate a TV to test on! Make sure your remote works on it first, then sight in on it with one side of the binoculars and shine the remote through the other side. You want the invisible projected circle of IR light to hit the front of the TV (specifically the IR receiver part of the TV which probably looks like a dark little window). Remember your training with the LED light!





Experiment with how far away you can make the remote work through the binocular optics. You will easily be able to exceed the normal range of an IR remote. Performance will be better in low light. I easily got about 40 feet of range with my binoculars and my Ninja Remote without any fiddling needed. I am sure it is capable of more - your mileage may vary but you will be able to easily exceed the remote's normal range.



Video Demo

Pictures and text is worth more than text alone, after all... Here is a garage-demo:

Appendix - IR Repeater Schematic

One method I tried before settling on the simple Binoculars system was to build an IR Repeater with an IR Laser as the output. The input consisted of shining the remote control into a photodiode.

It worked, but was finicky. Sighting in the insible laser beam had to be done with pinpoint accuracy which was very difficult. Too difficult to make the super-long-range made possible by the laser worth it.

The design I made for the IR Repeater is sound, however. You shine your remote (or other IR source) into the photodiode, and the IR signal is reproduced out of the IR laser on the other end.

Of course, you don't need to use an IR Laser on the output. If the output is a regular IR LED, the unit can be used as a repeater to send your remote's signals around a corner into another room. Or it could be used as an IR amplifier - taking the weak input from a single IR LED on the remote and outputting the same signal out a whole big bank of IR LEDs for the "brute force" approach.

You will need:



  • 5v power supply

  • IR photodiode (should have a dark plastic covering)

  • 1k resistor

  • 2x NPN transistors (2N3904 or 2N2222 should be fine)

Schematic:

(Click for a larger version)

Other Resources

Speaking of IR LEDs and optics, etc - you might enjoy the MILES TAG Do-It-Yourself Laser Tag system (uses no lasers).

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