PWM Fan - can it run directly off 3.3v, 5v or 12v inputs/GND?

[Trash80toHP_Mini]

I've got a case with 3 PWM fans and an incompatible (Beige G3) logic board. I'd like two fans to run off a power level a step below the third in any combination of the three voltages available on an ITX PSU.

Does this amount to a simple hotwire kluge or do they need a controller to function?

 

[luRaichu]

Does this amount to a simple hotwire kluge

Yes. Just hook up the red wire to your voltage and the black wire to ground

 

[Byrd]

... they will work fine but full RPM, so check the specs Trash80 that you're not buying a wind turbine

 

[Trash80toHP_Mini]

... they will work fine but full RPM

Assuming they're 12v max fans per PWM spec, they won't be full RPM @5v or 3.3v, no?

so check the specs Trash80 that you're not buying a wind turbine

I imagine I could build a hovercraft with a IIsi using these things. They were set up blow straight into this 2U server case thru a full frontal dust filter. I have them blowing out the backside, still sucking air in thru a different full frontal dust filter.



Ductwork will direct air straight thru the heatsink at 5v driven RPM, the other two are 3.3v RPM gravy I think.