Perfect. Thanks, Bert. I knew someone here would know something about these
caps.
On Wed, Jul 11, 2018 at 5:10 PM Bert Hickman <bert@xxxxxxxxxxxxxxxxxxxxx>
wrote:
> Hi Andrew,
>
> These capacitors date back to the 1980's. The good news is that they
> contain no PCB's. They use polypropylene film-kraft-foil construction.
> This predates newer "hazy film" polypropylene-foil dielectric systems.
> They are suitable for low duty cycle pulse forming networks and DC
> filtering applications. They will get warm in any RF application due to
> the lossy kraft paper layer. They have relatively long, high-inductance
> insulators instead of the flat low-inductance "dog bowl" insulators used
> in true high-current energy discharge caps.
>
> These caps are NOT built to handle the high peak currents involved in
> coin shrinking. I only know about their internal construction since I
> autopsied one after it failed - in coin-shrinking use. The first
> capacitors I used for shrinking were some surplus 54uF 15kVDC GE units
> (GE 30F1600). I acquired these in 1997. I also contacted GE engineering
> and they couldn't provide me with ANY specs or information on them even
> back then! Finding any specs on them today is likely an exercise in
> futility.
>
> I began trying to use three of them in parallel to shrink coins.
> Unfortunately, the caps began failing (losing capacitance) after 30
> shots. One then catastrophically failed in less than 50 shots. The metal
> case ruptured, disgorging a gallon or so of nasty blackish fluid and
> foil fragments onto the indoor-outdoor carpeting. The impregnant is a
> solvent - it immediately ate the backing off the carpet and soaked the
> concrete below.
>
> An autopsy indicated that the capacitor was designed with a hairpin loop
> in one of the capacitor buses. Each time the capacitor was discharged,
> magnetic forces flexed the loop, quickly ripping the bus from the
> capacitor rolls at the solder joints, causing internal arcing, and
> eventual an internal explosion.
>
> I would not use these for any high current (kA-level) discharges, but
> YMMV. Otherwise they are dated, but pretty good pulse or DC filter caps.
>
> Good luck and best wishes,
>
> Bert
> --
> Bert Hickman
> Stoneridge Engineering LLC
> http://www.capturedlightning.com
> +1 630-964-2699
> ***********************************************************************
> World's source for "Captured Lightning" Lichtenberg Figure sculptures,
> magnetically "shrunken" coins, and scarce/out of print technical books
> ***********************************************************************
>
> Andrew Cobaugh wrote:
> > Please excuse the off-topic-ness of the post, but I'm hoping someone on
> > this list can help me out.
> >
> > I am looking for information, hopefully datasheets, on some high voltage
> > capacitors that are long since discontinued. I have looked online and
> > cannot find any references to them. They are series 30F. These are the
> > catalog numbers and nameplate specs.
> >
> > 30F1427 3.3uF 10000VDC
> > 30F1427 5uF 10000VDC
> > 30F1431 13uF 10000VDC
> > 30F1404 46uF 5000VDC
> >
> > I contacted GE and the person that responded claimed they had no record
> of
> > them.
> >
> > They're large, rectangular, oil filled with dual ceramic bushings. I
> have a
> > bunch of these, and was hoping to use them to make a small can crusher or
> > exploding wire rig.
> >
>
>
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxxxxxx
> https://www.pupman.com/mailman/listinfo/tesla
>
--
andy
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla