Print PDF
Favorite
Email
Dont you hate when you use a projecter for your wii and have to strech the sensor bar wire to the projection screen? Now you can make your own wire less one for under $10!
Remove these ads by
Signing UpStep 1Part 1
to make this you'll need just a trip to your nearest radioshack or other electronic store!
1x 2 AAA battery holder
2x high output infrared led
1x switch
some wire
tape
THE ITEMS ABOVE ARE NESSACERY
THESE ARE OPTIONAL
solder
soldering iron
1x 2 AAA battery holder
2x high output infrared led
1x switch
some wire
tape
THE ITEMS ABOVE ARE NESSACERY
THESE ARE OPTIONAL
solder
soldering iron
| « Previous Step | Download PDFView All Steps | Next Step » |
sorry
good effort!
You need one 4.7-ohm resistor for a series of 4 1.28V 100mA radioshack high intensity IR LEDS
find out how to calculate it here: http://www.quickar.com/noqbestledcalc.htm
A LED is NOT a resistor it is a DIODE. that means if the voltage fluctuates the current and resistance can be nearly anything. It will eventually FRY.
Current Limiting Resistors are ALWAYS necessary with an LED. sure it will work for a few days - until there is a power fluctuation and then you fry one of your LEDs, and that causes the voltage to increase across all of them and then fry the next one... and the next one... just like christmas lights. IT's called THERMAL RUNAWAY.
Unless you want to turn your LED (Light Emitting Diode) into a SED (Smoke Emitting Diode) or friode, just stick a resistor on the front end of the circuit.
There is a very nice explanation here:
http://led.linear1.org/why-do-i-need-a-resistor-with-an-led/
and some LED basics here:
http://www.dansdata.com/caselight.htm
In the case of a silicon diode, the bulk resistance is small and decreases with curent, and the forward voltage drop is about 0.6v. Put 1.5v directly across a silicon diode and you'll have blue smoke in a matter of milliseconds. This is because, even though the diode forward voltage acts to reduce the effective voltage across the diode, the bulk resistance is so small that the remaining 0.9v or so causes LOTS of current to flow (Look up Ohms Law).
LED's aren't made of silicon. They're made of exotic compounds such as Gallium Aluminium Arsenide (GaAlAs), and Gallium Indium Phosphate, so their bulk resistances and forward voltages are much higher than for Silicon. It is possble to use a LED without a current limiting resistor IF the bulk resistance and forward voltage drop are high enough. Break open any cheap LED torch keyring and you will probably find just a LED - no resistor.
That all said, I wouldn't advocate using a plugpack to drive a LED without a resistor. This is because most cheap plugpacks only give you their rated voltage at the rated current. At lower loads, they put out much higher voltages. Check a 5v plugpack without any load on it and you'll most likely see 9v or so.
If you want to try running a diode directly from a battery it should work as long as you have the right diode. This is because the battery voltage doesn't change much under load. In the spirit of these forums, experiment! After all, the worst you can do is turn a 50c diode into blue smoke!
Seems to be a more complete system. I like their father-son kit idea.
LEDs require a current limiting resistor, so that the current doesn't fluctuate eventually frying your led after long term use.
The wii-mote is a Infer Red (IR) camera which tracks distance to the TV via the LED's he has. They are IR LED's set up at the same distance from each other as the Nintendo sensor bar.
All he has done is given its own power supply. The only reason you need to plug it into the wii is because of power.
I like this, but I've built mine into my TV case mod. Useful that.
To Meeboy, I'd suggest adding this somewhere in your instructions please. Or at least change the wording. Add it as another step so people at least understand why they're doing this.
-Cheers, Chris