LED Dimming and Brightening

kodi said:

One wire from PSU to Pot to fan
Another wire from PSU to Resistor to led

That would not dim it at all though...

~Lordbob

Sorry must have been another "Seniors moment" I will have to read the original post more carefully before i try to help.
I thought you wanted the LED's to stay fully on and not dimmed.

kodi said:

Sorry must have been another "Seniors moment" I will have to read the original post more carefully before i try to help.
I thought you wanted the LED's to stay fully on and not dimmed.

It's alright.

I want the LED to dim when I turn the fan down, and brighten when I turn it up.

~Lordbob

Again the simplest way to do this is to buy a small red or blue incandescent bulb to get the effect you are looking for. Very simple the bulb will work just like the fan does using the POT. Unless someone takes it apart you will never know it is not an LED.

I have just done a quick Google search and have found out that red LED's require a lot less voltage than other colors you may not be getting it to dim because there is still enough power to light it fully.
If blue is an option i would try it

Looks like if you use Highly Efficient LEDs and a circuit board you can dim some LED(s).

Check this out: Highly Efficient 0-100% LED Dimmer

or

Thanks Windowstar. Not sure I can figure that out on my own, or what. I will talk to my dad about it tomorrow and see what he says. I may just leave it with a regular LED (no dimming) because the knob has an arrow on it.

~Lordbob

WindowsStar said:

If you are talking about LED back lighting on LCD TVs they don't dim them.

No, was more an offhand remark. But LED's can be dimmed.

I do believe it has to do with getting the voltage down far enough to allow the led to dim. Perhaps experiment with more resistance until you find the correct amount to allow a dim LED at lowest fan setting (or lowest you will actually turn it down to, lest higher than complete lowest again gives you a bright LED), and brightning at the full brightness voltage. It may well be that the voltage difference between dim, and full bright may be too small a difference for you. A Guy

Did some googling:

http://www.mikesflightdeck.com/led_dimmer.htm

Starts getting into building a circuit, and finding the right parts.