Re: Vacuum pump for capacitor pumpdown

To: tesla-at-pupman-dot-com
Subject: Re: Vacuum pump for capacitor pumpdown
From: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Sat, 29 Aug 1998 16:13:48 -0600
Approved: terryf-at-verinet-dot-com

to: Gary

You get a much better vacuum if you have at least one stage with a storage
tank to pump into rather than pump directly.  Both the Bell Jar and the
"Scientific American Book of Projects for the Amateur Scientist", C.L.
Stong, circa 1969, provide excellent information in this area.  500-1,000
microns works ok for a cap pump.

DR.RESONANCE-at-next-wave-dot-net

----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Vacuum pump for capacitor pumpdown
> Date: Saturday, August 29, 1998 1:00 PM
> 
> Original Poster: "Justin Hennigan" <justinh-at-interlaced-dot-net> 
> 
> If I had time, I'd tell more.
> But go here, it's the best source of vacuum information you're gonna
find.
> http://www.tiac-dot-net/users/shansen/belljar/
> It's The Bell Jar.  enjoy.
> 
> -----Original Message-----
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
> Date: Friday, August 28, 1998 7:44 PM
> Subject: Vacuum pump for capacitor pumpdown
> 
> 
> >Original Poster: Gary Lau  28-Aug-1998 0833 <lau-at-hdecad.ENET.dec-dot-com> 
> >
> >Hi All:
> >
> >I'm slowly progressing with the construction of my new extended foil,
> >rolled poly caps.  The rolling is done, I now just have to complete the
> >enclosure.  My problem is how to draw the vacuum before backfilling with
> >oil.  I have a vacuum pump that I can borrow, a rotary vane unit.  The
> >specs say it should be able to pull a 26" Hg vacuum, although the gauge
> >only reads 22-23", could be that the fittings just need to be tightened.
> >
> >Is there a consensus on what degree of vacuum is required for cap
pumpdown
> >prior to oil filling?  Also, I've read descriptions of the pumpdown/fill
> >procedure, describing how the oil will foam or boil as it is introduced.
> >Could this be minimized by either heating the oil in a pot on a stove,
or
> >by storing the oil in an evacuated container for some time, to cause
> >outgassing prior to use?
> >
> >Regards, Gary Lau
> >Waltham, MA USA
> >
> >
> >
>