WiiLi.org

[Einlanzers]

OK. So at first I tried splicing a USB cable and using the +5v and ground with my spliced sensor bar. No go on that one...it seems it didn't draw enough power. I then tried using a simple 9V battery. That was and is still working. The question I have is... how much Voltage,Amperage,etc does the sensor bar need. I've looked all over it and can't find it anywhere. I've read online that you should use a resistor with a 9V battery or you'll end up frying the LEDs over time. I'm also thinking about getting a simple AC adaptor and splicing that into it, but I still would like to know the specifications of the sensor bar.

Thanks,
Einlanzers

[TheDro]

I don't know if you know anything about diodes, but as you add voltage, you could say that their "apparent resistance" diminishes which make them relatively easy to break. Based on the specs that I've seen, an IR LED should have around 1.2V. I don't know whether the leds in the sensor bar are connected in series or in parallel which would change things quite a bit. If all 10 are in series, they should need AROUND(rough estimation with no calculations and still not enough info to back this up althoug I do know how diodes work) 12 volts but if both sets of 5 are in parallel then you should need AROUND 6 volts which explains why a 9V battery would break them over time.

Tomorrow I'm heading over to the source (canadian radio shack) to possibly get some leds and they should come with their respective data sheet so I'll have more information. If they work exactly like regular diodes I should be able to tell you which voltage and resistance you need for proper operation.

EDIT: just found this http://www.wiili.org/forum/building-a--und-quotsensor-und-quot-bar-t154.html

[Einlanzers]

Ahh. That is a pretty helpful post. He explains that the USB doesn't supply enough Amperage (If I'm reading correctly) to support that many LEDs. OK so not having enough voltage usually wont power something and having too much can kill it overtime? That makes sense. The question is... how to I remedy that? I heard that you should use resistors. Would that mean that I need to find a resistor that is 3V (9V[Battery]-6V[Guesstimated Usage]) or something?

Thanks for the help so far,
Einlanzers

[Oinquer]

use ohms law...
U=R*I
U its the voltage you need to drop...that means...9-6=3V
I its the amperage of the IR LED's (in here i cant be certain... some consume little as 0.010A, while others consume 0.025 or more...)
lets use the 0.010 ... (10 mA)
3=R*0.010
R = 3/0.010
r=300 ohms
take this as a example only since i don't know the amperage of your LED's...once you have it you can make your math.

[Einlanzers]

The problem is that I don't know for sure the voltage I need to drop. Nor do I know the amperage of the LEDs. That only leaves me with the Voltage I start with so I have:
9-X=R*I
That's 3 variables that I can't solve for .
My question was a question of what these values were... I researched for awhile and couldn't figure out what these values were exactly.

Another question that comes to mind is...what if I resist to much or too little? Say I use your 300ohms idea and that is too much resistance? Will the LEDs be too dim? If it isn't enough resistance will that simply burn them out faster?

Thanks again,
Einlanzers

[Oinquer]

ok...i didnt got enough info from your post...
your using the official sensor bar or one made by you?
if yes it needs about 12V...but i read that 9V is enough...so just use the smallest resistor you can find (without resistor should work aswell without instant burn but lifespan is diminished) ...
if youre using homemade sensor bar i need more info.

[Einlanzers]

I'm using the Wii Sensor Bar that came with my Wii System. I merely spliced it and attached a 9V battery so far. I tested the Wii output on that port and it is indeed 12V, but I'm guessing there may be a resistor in the connector? I keep reading online that some sort of resistor is needed because it doesn't require 12V (or even 9V), but I can never get a straight answer as to what the Voltage and Amperage are