PWM compatible 3 pin 140mm fans

[GoNz0]

bit of a long shot but i need some 140mm fans that will work with a PWM output BUT 3 pin form. i dare say a 4 pin will work ok (so long as i cut the 4th wire off) as the fans capable of running PWM but the koolance controller card will be dishing out the pulse and not using the 4th wire on the fan.

i brought some noctua 140mm fans but they really dont like the PWM signal and keep running full pelt until the pwm signals 10% so you can expect those in the 4sale section soon

[Pob255]

Have you tested other fans on that controller? might be an issue with the signal as it should make non-PWM fans work by PWM
Off hand I don't know of any 140mm PWM fans it might come down to buying different fans and trying them.
You should be able to fit a normal 4pin PWM fan onto the controller and still have it work correctly, if there's no issue with the controller signal.

Have a look at the 9bladed NZXT 140mm fans http://specialtech.co.uk/spshop/cust...roductid=11639 I've got a 120mm version and it's a decent fan (not sure if it will have issues with the 3pin pwm signal though)

Oh just spotted this http://specialtech.co.uk/spshop/cust...at=1901&page=1 xilence make a 140mm PWM fan, no idea what it's like, just the only 140mm PWM fan I've seen.
And Ouch! at the cost

[GoNz0]

i had clocked that 140mm but no stock anywhere to test one. the corsair fans seem to work ok and the 120mm noctua work better than the 140mm, im assuming its there smooth commuter tech thats smoothing out the pwm signal to stop it doing its job!

i need to track down one of those pwm's to see if it works better

[Biscuit]

This might help?

http://www.frostytech.com/permalinkA...m?NewsID=69822

[GoNz0]

no m8, they run fast until the pwm gets below 10% that fix wont help at all.


and the fans and controller are all 3 pin

[Biscuit]

sorry im a bit confused as to the requirements i think. You want a 140mm 3 pin fan that can have its speed controlled by a PWM output? Or if possible a PWM 140mm fan where you can just leave off the GND?

Im not sure 3 pin fans ever work properly off PWM as the 12v output is constant and the speed is controlled by the pulse until it gets down to a certain level (hence your results).

[GoNz0]

if the fan can be controlled by an internal pulse then the koolance card that also uses a 12v pulse should in theory be able to run it in the same way without needing the 4th PWM signal pin as its already outputting a pulsed 12v


it seems the noctua fans smooth out the pulse http://noctua.at/main.php?show=smoot...drive_2&lng=en stopping it working as expected, ie it runs flat out until below 10%

[Biscuit]

When is the 12v a pulse though, i thought it was always just a DC voltage and the speed was adjusted in regular fans by lowering the voltage?

[GoNz0]

no, anyway back on topic please

[killie99]

how about one of these

http://www.kustompcs.co.uk/acatalog/info_2592.html

Or 1 of these

http://www.kustompcs.co.uk/acatalog/info_8662.html

Ah, I think I miss read your request, doh!

[GoNz0]

the fans and controller card is 3 pin, none of those will do it

you could be on the right track but the 4th wire generates a voltage that the fan coverts to a PWM signal so i don't think they would work off a 3 pin PWM header.