Wiring&Reistors

[adren1l1ne]

Ok I have done quite a bit of forum searching reading ETC. and have yet to find any real advice or answers. Now my problem is this. I know next to nothing of resistors, and the like. I know the one you choose is based on your power supply. Is there a simple easy way to determine what you need. I looked at the calculater that is on line and as I said I know nothing of this type of wiring so the calculator did me no good.
Thanx

[xwingband]

I moved it here since it definatly applies more here.

For the resistor you need to know a few things first: 1) Your batteries voltage 2) The forward voltage of the LED 3) what amperage you want to run your LED at

2 and 3 you'd get by looking up the specs of the LED. For a Luxeon there is a topic on that here. If it's not stickied I'll do it right after I post this (EDIT: it's in the LED Q&A forum). If it's for a decrative LED you'll have to look at the package.

The generic formula for the resistor is:

(battery voltage - forward voltage)/amperage = resistor value

That formula will give you the exact value to get that amperage. Sometimes it an odd number and you'll have to "over-resistor" it. Using an online calculator will do this automatically for you and round it to the closest standard resistor made.

[987654321a]

dangit.... i had a website but i forgot it, it tells you exactly which resistor your should get depending on your voltage/amperage.

[james3]

Dang we have gone over this snitz a million times

OK here is a nice and easy way to do it since that seems to be what everyone wants.

Get a 2.2ohm 5w resistor and the 4aaa or aa batt pack. use that with a 3w LED and you will be good to go.

[Do-Clo]

James at least 100 times