How to seperate LEDs from fan power, to stop them dimming

[Muel]

I'm planning on a pretty hefty modding project, which involves filling my case up with the Corsair purple LED fans. The colour and brightness is great, but the noise level of these "quiet" edition fans is insane. At 12v they sound like they're about to take off!

What I want to do it isolate the LEDs from the fan motors, so that I can make the LEDs switch on and off seperately from the fans, and have it so that the LEDs are always at 12v, whereas the fans motor voltage is variable.

Does anyone know if the LEDs in these fans are 3v? And if so, can I just wire each fan's LEDs in series and connect to a separate 3 pin cable, plug it in watch it go? It'd be nice to have the fans reusable so would prefer to just snip the existing LEDs from the little circuit board, wire them seperately and away I go?

Thanks!

 

[Tealc]

I tackled something similar a few years ago in one of my fan mod tutorials. I added LEDs to a non led fan and went a bit overboard with the quantity but the principle is there, or at least some of the methodology will be similar.

http://forums.overclockers.co.uk/showthread.php?t=18172810

Purple white and blue LEDs will typically be 3v or more forward voltage so you might struggle on 12v. Better would be having 2 LEDs in series with a 150 ohm resistor or so.

 

[Muel]

Cheers for that, got some experimenting to do now then!