On Jul 26, 12:28*am, klem kedidelhopper
wrote:
On Jul 25, 6:28*am, KR wrote:



On Jul 23, 10:18*pm, klem kedidelhopper
wrote:

On Jul 22, 8:44*am, (Wolfgang Allinger) wrote:

*On 19 Jul 11 at group /sci/electronics/repair in article
*(Wild_Bill) *wrote:

Much depends upon what type of motor is in the ceiling fan. There are
more than one type of AC motors without brushes.

Klem/Lenny hasn't revealed what type of AC motor he's referring to...
nor anything specific regarding the "generic" controller that wasn't
supplied with the fan.

Here in PY there are lots of ceiling fans from Wahson/China.

230V/50Hz

They use a separate autotransformer in an aluminium housing (15x9x4 cm) *
as controller.

It is in series with the motor and has 7 taps and a turning switch with *
weird numbered positions from 0 = off and 1=max ... 7=slowest speed!
The motor so gets between 230V and down to some 80V.

My 5 Wahsons did not buzzing, even in slowest speed.

However I have 2 fans (also made in china) with no external controller *
but a small hanging line which switches between 3 different speeds by *
taping different positions in the motor winding. They both are buzzing *
in speeds below max. I think thats in the remaining active sectors of *
the winding.

None of these motors have brushes.

Saludos Wolfgang
*--
Meine 7 Sinne:
Unsinn, Schwachsinn, Blödsinn, Wahnsinn, Stumpfsinn, Irrsinn, Lötzinn.
Wolfgang Allinger * Paraguay * * * * * * reply Adresse gesetzt !
ca. 15h00..21h00 MEZ *SKYPE:wolfgang.allinger

I *would like to try the trick with the capacitor in series with the
slowest tap on the speed control however I am a bit unclear as to *how
to "size" the capacitor. By "size" I mean that it seems like if the
motor draws one amp for example, (and I will confirm that first), I
will need a capacitor that can handle more than that amount of current
flowing through it. I remember dealing with this sort of thing in
electronics school, but admittedly that was a very long time ago and
I've forgotten how to work this out.

For instance, I have a 4uf 250V AC capacitor that I would like to try..
This part is designed for motor starting. This is a fairly large
capacitor. The control box measures approximately 8" x 6" X 3". Most
of that space is taken up by the switch and transformer. There would
not be room inside for anything this large. Or do I need to use
anything this large? Thanks, Lenny

Took a look inside a controller today, they have 1.8UF and 3.6UF (at
50hz) capacitors *(motor was labelled 65w)

Another thing you could to, if you have access to someone who is
reasonably accurate in metal folding, is to fold the fan
blades down a little bit more to change the pitch. (alternately you
might try packing washers between the blade and the motor under the
mounting screws to tilt it slightly more - dont know if it would work
but worth a try)

A friend found that out the hard way years back when unknowingly put 4
blades meant
for a 3 blade fan onto a 4 blade fan body and nearly drove himself mad
trying to work out why he couldnt get it to go fast enough.
He had picked up several fans and a box of blades free from a place
that was being renovated and just picked out 4 blades that looked the
same.

It was a very small difference in blade angle, but knocked off an
enormous amount of speed

But wouldn't that also load the motor more than it should be? *Lenny


definitely would, but whether or not it damages the motor is another
matter.
as long as there is enough airflow around it to not let it overheat it
should be ok ?.