Re: MMC cap bank

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

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

You're probably right.. There's also a difference in what the impregnant
does between plastic film capacitors and the kraft paper kind.  In the kraft
paper and aluminum foil type, the oil is the dielectric, and the paper is
just a spacer.  In the plastic caps, the plastic is the dielectric and the
oil is there to fill voids and reduce corona, etc.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, July 04, 2003 8:00 PM
Subject: Re: MMC cap bank


 > Original poster: "Crow Leader by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<tesla-at-lists.symmetric-dot-net>
 >
 > Tesla list writes:
 > >Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 > ><jimlux-at-earthlink-dot-net>
 > > > >Beau has been experimenting with RF caps since we were all knee high
to a
 > > > >grasshopper (or less) and is a very respected professional in this
area.
 > > > >PCI, CSI, and Maxwell all use silicone oil in their caps.  Short cuts
 > > >
 > > > I don't believe Maxwell uses silicone like everybody else. They
somehow
 > > > even pull off using paper in high rep pulse caps, where everybody else
 > >just
 > > > uses polypropylene and a compatible oil. My General Atomics caps is
full
 > >of
 > > > isopropyl biphenyl, and my PCI caps are silicone oil, all of which are
AC
 > >GA/Maxwell uses Castor Oil in their paper caps (So called Series C Energy
 > >Discharge).. One advantage is that the dielectric constant of castor oil
is
 > >in the area of 5, compared to 2.5 for mineral oil, so you get twice as
much
 > >C in the same volume. So, you can maybe design a bit more margin into the
 > >cap while keeping the energy density the same.  The white plastic cased
caps
 > >from GA/Maxwell are mineral oil and polypropylene, as far as I know... I
 > >can't find my application note which describes it in gory detail.
 >
 > I highly doubt this. They use a whole bunch of impregnants in the many
 > plastic cased caps they make. It's not likely they use mineral oil and
 > polypropylene either. Mineral oil dissolves polypropylene. I found this
 > when I wound my own caps, and this was confirmed by several other
 > companies. I had a decent chat with General Atomics cap people when they
 > made me a cap, because I had to ask how paper was going to be used, when
 > none of the other manufacturers I spoke to quoted anything other than hazy
 > PP film and their favorite oil. Oddly, General Atomics was still cheaper
 > than the others, so I went with them.
 > KEN
 >
 >
 >
 >