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Fw: Rolled Capacitor question.





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> From: Jim Lux <jimlux-at-jpl.nasa.gov>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: Rolled Capacitor question.
> Date: Thursday, February 17, 2000 4:03 AM
> 
> I'm sure you've probably heard this before: it is probably cheaper and
more
> efficient to build an MMC than a rolled plastic cap.
> 
> However,  the idea behind vacuum pumps and petcocks is to use the pump to
> pull a vacuum on the oil filled unit to assist in removing any air
bubbles
> that are inside the roll.  Air bubbles lead to premature failure: air is
a
> much worse insulator than oil or plastic, and the nonuniformity of
> dielectric (air has a different dielectric constant than oil or plastic)
> leads to a field concentration, which also leads to failure. The idea is
> pretty simple: add oil, pull a vacuum, apply low ac voltage (several kV)
> which mechanically vibrates the internals of the cap, wait a few days,
> close valve after all the air is out.
> 
> 
> 
> ----------
> > From: Tesla List <tesla-at-pupman-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Rolled Capacitor question.
> > Date: Wednesday, February 16, 2000 6:23 PM
> > 
> > Original Poster: "Bryan Miller" <ftbll-at-MailAndNews-dot-com> 
> > 
> > Hello Everyone,
> >        I have another question about capacitors.  I am planning on
making
> a 
> > rolled capacitor of the type Richard Quick describes in one of his text
> files.
> >  He mentions using a vacuum pump and a petcock valve for filling it,
but
> never 
> > expands on it.  I was wondering if anyone has any further information
> that 
> > would assist me.  Any advice or resources would be greatly appreciated!
> > 
> > 
> > 
> > Bryan Miller
> > 
> >