LED question

[dunerinaz]

If an LED has a given voltage range, would that same LED be brighter at the high end of that range or would the brightness be the same no matter what? I was just wondering if the LED's on my RTR Wraith would be brighter if I got rid of the stock controller and just ran them off a switched 9 volt source.

[KillerBlackbird]

You'll have a lot less headaches with the controller. Different color LED's require different voltages to work, red needs less than white. I'm having that issue now after adding the 5-light light bar to my Wraith, Im going to need to rewire the Axial white 5-light string to get the LED's to illuminate as all 5 need 18V.

[rockhugger]

yes, it would be brighter.. but the the LED's are probably not rated at a very high MCD output. You'll have to add resistors to each light probably also, which at that point, you might as well build it from scratch... I'm guessing here, but I bet the controller has all the reisitors on a board. so if you remove the controller you'll need res.

[braq]

yes, the higher the voltage the brighter,
here is a good info on it
LED center » Why do I need a resistor with an LED?
however LEDs are also highly non-linear as you get toward the max. voltage, current rises dramatically and and that surely means it fails pretty soon.

So in case you are already running close to their max. voltage (what color, what voltage do you get from the controller?) better switch to one that has a higher output (mcd rating),

cheers

braq

[dunerinaz]

I just checked the stock wraith controller. For the two red LED's, output was 4.4v, and for the four front white LED's it was 15.5v. These are all wired in series. I'm not at all knowledgeable with electronics, but how can the controller be putting out over 15v when hooked up to a 2S? Is this a good voltage to power high output LED's? The stockers just don't look very bright.

[dunerinaz]

Can someone explain forward and reverse voltage with LED's? My stock Axial controller is showing 15.5v output and I'm wondering if that would power two 10mm LED's for use as headlights.

[KillerBlackbird]

This might help or totally confuse you lol: Light-emitting diode - Wikipedia, the free encyclopedia

Essentially a diode acts like a check valve does for water, it only allows electricity to flow one way.

The light controller in your Axial light kit works as a boost converter for the LEDs to get their proper voltage. The 4 white LEDs need about 3.6V each and they're wired in series. This is why the white LED output is higher than the red rear output. Red LEDs don't need as much voltage.

If you're adding the two 10mm LEDs to your stock 4-light set up they might need more voltage. If you know the specs of your 10mm LEDs there are a couple sites online that can tell you what the best way to wire them and how much power they'll use/need.