post #11 of 11
If the fan is spinning in a vacuum and zero gravity; then yes the speed would be near directly proportional within a certain range of its maximum rated input. but here on earth the force exerted on the fan blades in motion is the square of its speed. But we also have to take into account the a brushless DC motor, which is really just an A/C motor with a controller, suffers back emf that is definitely non-linear. So the answer would be "No" the speed of the fan is not directly proportional to the voltage applied.