Can LED cooling fans be speed controlled ?

[rmaciag]

I have already posted two related questions here but I received no feedback.

In the mean time I figured out that most LED fans (probably) require
a steady 12V power to keep the LEDs alight.
Therefore connecting them via 3 pin connectors to the fan controller
is not normally recommended.

Is it then true to say that you either get lovely LED fans that you cannot manually control (via a controller unit) or
you should opt for plain fans that can be connected to the controller.

There appears to be another option : Smart LED fans which "control" themselves via integrated temperature sensor
(like the ones from Thermaltake or Antec).
Again those should not be connected to the fan controller (I suppose).

Am I right or I am talking complete rubbish ?

[Butcher]

Should be fine TBH. Either you'll undervolt them which will cause the LEDs to dim (LEDs are not harmed at all by undervolting). Or you'll be using PWM, which make make the LEDs flicker slightly, that won't damage them either - flashing is not a problem for LEDs. PWM for brushless fans will typically be in the range 60-200Hz so I doubt you'll notice any flicker tbh.

[rmaciag]

Many thanks.
I know that the subject is a bit ... boring !
I just want to finally get my PC project completed.
No more issues, no more shoping around etc ... at least for a while.
With all the hardware working I could, at last, do some useful work / play with it
(still the broadband connection is not working so
I have enough trouble with chasing the ISP !).

[muddyfox470]

ive got a fan (of my bros) at 7v by using th echeap undervolting method, and to add insult to injury the fan is a cheap LED one from ebuyer.

the leds are still bright, if not as bright and is quieter too

thats my experience!

[Butcher]

As long as you stay above the forward voltage of the LEDs (typically ~2V) they will glow fairly brightly, LEDs aren't as voltage sensitive as filament lamps.