RE: static gap fan speed

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ted Rosenberg by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Ted.Rosenberg-at-radioshack-dot-com>

John and all:
That is not the first time I have heard that a variac connected to a fan can
be a benefit to control air speed. My question is, must the controller be a
some what costly variac? How can you determine if something as simple as a
motor control available at your local Ace Hardware will work? I am guessing
that the type of fan motor determins this. If so, what types of fan motors
can be controlled with what types of controllers?

Thanks

And
Safety First

Ted

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, July 11, 2001 8:35 AM
To: tesla-at-pupman-dot-com
Subject: Re: static gap fan speed


Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>

In a message dated 7/10/01 8:43:43 PM Eastern Daylight Time,
tesla-at-pupman-dot-com 
writes:

> I was looking at a static gap for sale on eBay (at:
>  http://cgi.ebay-dot-com/aw-cgi/eBayISAPI.dll?ViewItem&item=1615460756
>  ) and was reading the sellers instructions for adjusting the fan speed. 
>  According to these instructions, there is an optimal fan speed, above
>  which spark length decreases.  I've never read this before, and am
>  wondering if anyone can corroborate this.  I always figured that I
>  didn't have to worry about too much air through the gap, but just too
>  little.
>  
>   - Bill V.

Bill,

It is true that fan speed can matter in some coils.  It all depends
on the CFM of the fan, the "natural" quenching ability of the
coil, etc.  Some coils can use the full fan speed with no detriment.
It's not that too much air "over-quenches", rather too much air
can intermittently stop the gap from firing.

John Freau