Re: MMC or Maxwell? Which is better?

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

Original poster: "Crow Leader" <tesla-at-lists.symmetric-dot-net> 

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, March 03, 2004 12:20 PM
Subject: Re: MMC or Maxwell? Which is better?


 > Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net>
 >
 > Ken,
 >
 > The dielectric system was polypropylene film and kraft paper immersed in
a
 > fairly aromatic dielectric fluid. The kraft paper was apparently used to
 > facilitate wicking of dielectric fluid inside the capacitor rolls during
 > manufacture.

Vacuum impregnation or etched film is for getting impregnant inside the cap.
General Atomics wanted paper in the cap they made for me, to somehow reduce
stress on the dielectric film. Some other caps that are "tesla coil"
copatible I have are lower voltage caps with straight polypropylene film and
silicone impregnant. Utility company power factor caps have the largest
winding sections I've seen in high voltage caps, and they are able to
completely impregnate them without paper, which seems impressive.

This rotation process seems pretty unique. All the catalogs for high voltage
liquid filled caps I see state any operation orientation is acceptable,
since they either don't have any air in them, or just a small bubble of air.
The general atomics cap I have has a small air bubble that you can see up on
the terminal section, it doesn't seem large enough to cause anything to ever
dry out. All the metal canned caps are apparently air-less and therefor
bubble free. Even large canned electrolytic caps (with the exception of
"long life" units from Evox) are full of air and have no free fluid
splashing around. Electroyltics depend on the paper being wet to function
properly, drying out would destroy them. This doesn't seem to happen unless
the can leaks.

KEN


 >
 > -- Bert --
 >
 > Tesla list wrote:
 >
 > >Original poster: "Crow Leader" <tesla-at-lists.symmetric-dot-net>
 > >Interesting pics, as you can see from the first few pics and clearly in
the
 > >xray image, these caps are really 8 sections in series, two sections per
 > >"pack". Such a case (PVC pipe) seems sort of iffy if you're going to
 > >experience a fault. All it can do is pop the ends off and spew junk
 > >everywhere. There is no room for expansion, or places to bulge, like in a
 > >metal can or more flexible plastic case. Do you know what the dielectric
and
 > >impregnant were? I see the foil and kraft paper, but obviously cannot
tell
 > >more from the pics.
 > >
 > >----- Original Message -----
 > >From: "Tesla list" <tesla-at-pupman-dot-com>
 > >To: <tesla-at-pupman-dot-com>
 > >Sent: Sunday, February 29, 2004 8:05 PM
 > >Subject: Re: MMC or Maxwell? Which is better?
 > >
 > >  > Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net>
 > >  >
 > >  > Hi Terry,
 > >  >
 > >  > I had one of these CP caps explode in my lab when testing it for Don
 > >  > Froula, a local coiling friend, back in 1996. It created a loud bang,
and
 > >a
 > >  > ball of yellow flame exited, creating one heck of an oily mess to
clean up
 > >  > afterwards. The wife was not amused. The posting and discussion can
be
 > >seen
 > >  > in the archives from 1996:
 > >  > http://www.pupman-dot-com/listarchives/1996/october/msg00169.html
 > >
 > >Tin alloy sounds about right, High tin solders seem to work on aluminum.
 > >I've seen these connections fail in other caps before, even with sturdy
 > >looking connections, and low currents. Using normal 60/40 on aluminum is
an
 > >interesting soldering project of you're ever bored.
 > >KEN
 > >
 > >.
 >
 >
 >
 >
 >
 >
 >