[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] Controlling Speed of an AC (Muffin) Fan



Hey Gary,
I took a look at your sucker gap. Very nice! Do you think it would be effective at all with my 4" RQ gap on top of a vacuum motor like yours? I think it might be too wide to do anything...
Thanks,
Brandon

On Feb 27, 2010, at 6:41 PM, "Lau, Gary" <Gary.Lau@xxxxxx> wrote:

AC induction motors like what's in the fan you cite really are not really supposed to be speed-controlled. It may work to some degree, but I doubt it will work well. But for the purpose of blowing on an RQ gap, I don't think one needs to control the speed. I don't think there's a critical sweet spot in air flow; anything above some reasonable flow rate is all you need and it won't improve things to have more. Just apply full power to it.

I mentioned using a lamp dimmer with my sucker gap. The vacuum cleaner motor used in this gap is called a "universal" AC/DC motor, not an induction motor, and its speed is easily controlled with a dimmer. And, that gap needs only a fraction of the full-speed airflow that motor is capable of, and full-speed operation is VERY noisy, and I just don't want that noise and that much power being used.

Regards, Gary Lau
MA, USA



-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
Behalf Of Brandon Hendershot
Sent: Saturday, February 27, 2010 5:54 PM
To: Tesla Coil Mailing List
Subject: [TCML] Controlling Speed of an AC (Muffin) Fan

Alright,

So I plan on purchasing this:
http://www.mpja.com/prodinfo.asp?number=17780+FN
 AC muffin fan and I need a way to vary its speed. I was thinking of
using a rheostat, but Paul suggests otherwise. Then I thought of using
a dimmer switch, but I remember trying to control my drill press with
my variac (kinda the same, right?). It wouldn't work because you need
to control the frequency of the electricity, not the voltage like you
do with most DC motors.

Anyway, what do you guys use to control your AC motors on your rotary
gaps or spark gap fans?
Thank you,
Brandon

P.S: I only opt for AC motors for their immunity to the coils magnetic
field. One more thing on the topic of fans, should 200 CFM be good
enough to quench my RQ gap? I'm running a 15/30 NST.


_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla