FreeTrack Forum

Hello Freetrack peoples!

Recently, I've bought three Infrared lights to use for Freetrack. I bought it along with some batteries. Since I'm no electronic nut, I forgot to get any good wire with it.

Since I have dismantled and assembled a dozen of computers, I have tons of these laying around.



The idea is that I would cut open these wires at each ends and let a piece of metal stick out. As I said, I'm no electronic nut, but how am I going to put this to work?

Can I connect the IR's individually to a battery? Or should I make a small circuit with a resistor? The thing is, I don't even know where to get a resistor or what I should get.

Is there such thing as + and - wires? I know how electricity works to some degree, with the voltage and plus/minus.

Somebody help me out here! Thanks in advance!

EDIT: Can I use copper wire if this doesn't cut it?

Hello Arno,

Let me redirect you to Ben Meijers excellent buildguide.

http://forum.free-track.net/index.php?showtopic=1856

Further, there are many examples on how to build pointmodels, all in all it is not very complicated even for elektro laymans.
If you are going to make a battery powered pointmodel, it is perhaps the best to make a parallel circuit (like Ben Meijer's battery example), although you can make serial too, but then you need adequate powersupply (4.5V minimal).
Make sure you connect the LEDs proper (+ on +), they only emit light when they are properly connected.
And yes, you can use copperwire. Where you planning to use something else then?  

Resistors aren't hard to find, a Radioshack or Conrads will have them. There is a Wizard on the main page that can calculate resistors for you, but I don't know if it is for serial or parallel circuitry. My advice is to go for the same resitors as in the example if you are going to use the same powersupply.

My tip is to make a simple working pointmodel first and use it for a while, then when you have some experience with it you can always make a better pointmodel.

Arno....

I'm new to this too and just yesterday I was testing an IR set-up. It's VERY easy...I was just using electrical tape to make temporary contacts and that worked fine.

Two things that are invaluable for testing are a multimeter and a real digital camera. The multimeter is for checking polarity/voltage and as most good cameras can see IR light, they are great to check to see if it's even on.

Simply put, use the multimeter to fine the voltage of a AA battery. Check to make sure that falls in the range of the LED. If it does then don't even worry about a resistor.

Once you have done that...

Tape a wire from the battery's (+) to the long leg of the LED. Then tape a wire from the short leg of the LED to the (-) side of the battery when you want to turn it on...as simple and easy as that...

This is the down and dirty way to do it and is temporary. When you want to finalize things, then there are a few easy ways to make it very clean (battery holder, switch)...

Don't be put-off...just watch polarities and don't leave the test set-up connected when you walk away.

Oh, all I did for the LEDs is to push the pins through and old hat's forehead area...again...quick and dirty...

You can make this as easy or complicated as you like...(I'm going with easy)

Post any questions...


EDIT

I should stress the fact that IF you check your supply voltage and it's within the spec of the LED then it's same to not use a resistor. But you MUST know both the supplied voltage AND the tolerances of the LED. IF you don't have both then you (a) shouldn't even proceed and (b) if you do, use a resistor around 20-222ohms. Also, this test is really for just a normal AA battery...not for an adapter.

Thanks for the help guys!

I've got the right stuff now and I tested one led on a 4xAA battery holder and surprisingly it worked! Today I'll try to get it straight!

I even bought a Microsoft HD3000!

Good to hear Arno...

With 4xAA just be aware of the total voltage supplied vs what you need.

When you get tired of replacing batteries, you'll want to switch to an adapter. A bit more tricky but really not too bad. At this point, resistors are a good idea.

Cheers!