Re: MMC cap bank

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

Original poster: "bob by way of Terry Fritz <teslalist-at-qwest-dot-net>" <yubba-at-clara-dot-net>

hi all,
thanks Jim for reminding me that the oil is the dielectric in Kraft paper 
caps. i knew there was a good reason for using it in transformers  as well 
as caps.  The  other reason it is used  is that it doesn't melt.
cheers
bob

At 11:44 05/07/2003 -0600, you wrote:
>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
> >
> >
> >
> >
>
>