What size resister for LED's
 

I would like to know what you folks recommend me to get for a resister for wiring up some LED's hooked up to a 9v battery.

Thanks

It depends on what wattage LED you want.

1W or higher will require heatsink aswell...

If you don't need super bright light to illuminate the night but just want a small light... just get yourself one of those LED Light clip on for caps. Those come with 5 LEDs and usually run at 3v. So you can get it out of it's casing and do the wiring to how ever you want... power it with 2xAA.

Needed that, thanks.

another good link here

I will be wiring 3w LED's. I want to use a 9v battery to power them and have the hooked to a switch. Probably no more than 10 on one switch.

Any recommendations for someone ignorant to all this electrical stuff like me? A simple wiring diagram that a lei man can figure out would be great too.

Thanks

That is a cool site, but how do I know what the "diode forward voltage" is, and the "diode forward current (mA)"?

Thanks

should say on the paper work with your LEDs...or on the site you picked them up from..

Its really not as simple as saying maybe 3 or maybe 10 led's from a 9 volt.

If they are different colors, the voltage requirements will probably be different.

If you can come up with a pot, like a volume pot, (variable resistor) that does lower ohms, then hook up your LED's and 9 volt with the pot in series and adjust it to where they just come on and start to get bright.

OR

hook everything up except leave one side of the battery open, and hook up different resistors until they just start to get bright.

I have 4 led's in series on one of my cars with 160 Ohm resistor in series to the 9 volt. It is 2 red and 2 blue LED's. The blue one's are dimmer than the red one's because of their nature, but If I lowered the resistance there might be a chance of blowing out the red one's.

If you want some white ones for head lights and some red ones for breaklights and this and that, you might as well purchase a LED controller made for the job. It gets complicated.

Hope that helps

Sounds like an LED driver would be a good bet for your situation. Here is a neat little one I ran accross. You won't need resistors. http://holmeshobbies.com/product.php...&cat=13&page=1

I'm using this one ;) http://www.hebeiltd.com.cn/?p=zz.led...tor.calculator Nice name btw ;)

Thanks Everyone! Awesome info.