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Re: spark gaps
Tesla List wrote:
>
> >From bert.hickman-at-aquila-dot-comWed Oct 23 22:14:09 1996
> Date: Wed, 23 Oct 1996 09:29:09 -0700
> From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: spark gaps
>
> Tesla List wrote:
> >
> > >From rwstephens-at-ptbo.igs-dot-netTue Oct 22 21:44:46 1996
> > Date: Tue, 22 Oct 1996 22:04:58 -0500
> > From: "Robert W. Stephens" <rwstephens-at-ptbo.igs-dot-net>
> <SNIP>
> >
> > All,
> >
> > I've been meaning to share my thoughts on the use of a vacuum cleaner
> > blower to negatively pressurize a fixed gap spark gap container and
> > draw outside air through the gaps and then after electro-treating the
> > nitrogen in the air into nitric acid and the oxygen onto ozone, this
> > nasty stuff gets sucked through the windings of the blower motor,
> > since vacuum cleaner blower motors are designed that the air sucked by them
> > passes over and through the motor windings for cooling. Has anyone ever
> > heard of the concept that ozone attacks electric motor insulation and shortens
> > motor life? Somehow this design concept appears flawed to me.
> >
> > rwstephens
>
> Robert,
>
> American Science and Surplus has a high speed 120 V vacuum
> motor/assembly ($12.00) that sucks clean air through the motor! I just
> replaced my previously zapped motor, and discovered that the little fan
> on the motor shaft at the top draws clean air through the motor and into
> the vacuum chamber. This probably reduces the total vacuum you can draw,
> but otherwise it seems to run OK! Maybe it was a manufacturing screw-up,
> and this is why they're surplus!
>
> -- Bert --
Bert:
I also purchased a vacuum motor from American Science and Surplus and
think it is a good deal. As a point of information the motor I received
has a die cast aluminum endbell that only the motor shaft passes
through. There is no other openings on this particular motor, which is
called a "HCX-SINGLEPHASE SERIAL MOTOR" Made in China, on the label. The
sheet metal fan housing only has the single suction opening on the
bottom, with no visible means of the stator cooling air to pass into the
actual suction chamber. I'm sort of cheating here. Since I've worked
in motor manufacturing for 20 years, I've seen a few of these before
-- we machine about 11,000 endbells per day at this point. I was going
to disassemble this one to see if there might be a shaft seal too, but
it works so nice, why risk messing it up! Yours might be similar to this
one, take a peek down by the end turns of the stator winding that's
closest to the big fan housing and if your's is the similar, you'll see
it is a solid casting--tough to see! Enough suction to pull the walls
down.
Chuck