• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

LEDs on a GPU fan header?

RedWagnum

RedWagnum

Gawd
Joined
Mar 30, 2007
Messages
615
Anyone ever done this? The other day I was thinking about running some 12V LED strips off my system fan controller and it got me thinking about this. I have a HIS 6950 that is water cooled so the fan header on it is just sitting there doing nothing. I figure it ought to be able to supply at least 100mA or so (no specification on the fan but it is a reference design card) so that should be enough to run about five 5mm LEDs. Problem is that it is PWM (4 pin connector) and I'm not sure how to hook it up.

Control should not be a problem. I can set CCC fan control to auto but I have never seen it go above 30% to 35% since temps never get above about 65c max (this is with a 6970 BIOS and 945/1345 overclock!) But I can control it manually in CCC or from SpeedFan.

So is this even doable or am I just spinning my wheels in the silicon?
 
Yeah I was debating whether to put it here in case modding or there in electronics. Figured here would get more views. But whatever. Move it or not. :)
 
Last edited:
I would think you could definitely do this, although whether or not it will do what you really want is another matter. I guess you want LEDs that appear to get brighter as the GPU's apparent core temp increases?

I would think the fan header should be able to provide enough power for some LEDs, but you could always just use the PWM and ground wires to drive a transistor, and then get power from one of the power taps on the PSU.
 
RazorWind said:
I would think you could definitely do this, although whether or not it will do what you really want is another matter. I guess you want LEDs that appear to get brighter as the GPU's apparent core temp increases?
Click to expand...

That was the general idea but with such a low fan power percentage I doubt I would see much difference in brightness.

I would think the fan header should be able to provide enough power for some LEDs, but you could always just use the PWM and ground wires to drive a transistor, and then get power from one of the power taps on the PSU.
Click to expand...
Hmmm... May have to try that just for grins. I have a bunch of 2222's, 3904's and 3906's available. I'm guessing PWM to base, gnd to collector, emitter to LED- and 12V to LED+ (with the resistor in there somewhere). Sounds simple enough. Just have to find a matching 4-pin connector without having to wreck the original HSF assembly.
 
You must log in or register to reply here.
Back
Top