Re: brushless AC speed control?

From: Robert Morein (nowhere_at_nowhere.com)
Date: 07/10/04 

Date: Fri, 9 Jul 2004 23:29:51 -0400

"Julie" <julie@nospam.com> wrote in message
news:40EF3E74.A4794D58@nospam.com...
> Robert Morein wrote:
> >
> > I have a need for an extremely low speed fan to noiselessly cool a hifi
> > rack.
> >
> > A typical house fan is powered by a four pole AC induction motor.
> >
> > I considered using a power tool speed control, but these controllers are
> > designed to work with brush-type motors.
> >
> > I am guessing that by using such a controller to reduce the speed of a
> > brushless AC motor, it would overheat if the speed of the motor was very
> > much reduced.
> >
> > Am I correct? Suggestions for an alternative very-slow-speed fan?
>
> Have you looked at Peltier solutions? Or do you need to move air?
>
> If you need to move air, brushless DC muffin fans (some are specifically
built
> to be low-noise) may be a solution. You can slow them down as much as
needed
> by reducing the voltage.

This is an air-moving requirement, but a muffin fan won't cut it.
The object is an open frame rack of hifi power amplifiers totalling around
1200 watts rms.
In a closet, there is the danger of a static air situation.
Fortunately, the closet has two doors.
If I put a big, slow fan at one end, it will create a draft through the
closet.

Quantcast