Working out fan speed at different voltages.

.:SAmSuNG:. · 11 Aug 2015 at 23:05

So my fans are run at 1900rpm at 12v but would like to figure out what they would run at 9v and 7v.

Is it as simple as:

1900 ÷ 12 = 158.3

Then

158.3 x 7

And

158.3 x 9

Or am I way off how this actually works?

C64 · 12 Aug 2015 at 03:21

Why don't you try it hasn't your board got fan controls for sys fan headers ? most do 12v 7v 5v

Tealc · 12 Aug 2015 at 07:39

Motors are fairly linear so as an approximation as you've done is probably close enough. The friction of the motor spindle and bearing will have an effect on the linearity but I doubt it would be all that significant.

.:SAmSuNG:. · 12 Aug 2015 at 08:32

C64 said:
Why don't you try it hasn't your board got fan controls for sys fan headers ? most do 12v 7v 5v

Im only using one header to a fan controller for cable management reasons and the fan controller wont run them slow enough.

Tealc said:
Motors are fairly linear so as an approximation as you've done is probably close enough. The friction of the motor spindle and bearing will have an effect on the linearity but I doubt it would be all that significant.

Cool thanks.