On Sat, 03 Aug 2013 01:43:16 -0700, Ashton Crusher
wrote:

On Mon, 29 Jul 2013 20:45:02 +0000, passerby
m wrote:

replying to The Daring Dufas , passerby wrote:
the-daring-dufas wrote:

You could try a regular light dimmer.



Small AC fans usually have shaded pole motors, RPM of which is frequency
dependent. By cutting off part of the phase with a light dimmer you will
just make it start even harder than it already is for this type of a
motor. There may be *some* RPM control due to torque losses when dimmer is
dialed down, but it's only a small percentage point around the designed
RPM, not from 0 to the max.

I've put dimmers on fans and all you do it trade off some fan blade
noise for increased motor noise because the solid state dimmers just
chop the current up and make the motor "buzz".

Not in my experience. In one case the dimmer was a foot from my ear
when I lie down and the fan was 18 inches. Still heard no humming or
buzzing. And since the reason I use the dimmer is mostly to get rid
of noise, I would notice.

There is probably a lot of variety in motors and fans, and even maybe
dimmers.

The only way to do it
without the buzz is with an old fashioned transformer based
dimmer/motor controller.