Re: plate caps

["Garth van Sittert" <garth-at-mediasupplies.co.za> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

I was looking at specs on polypropylene the other day and noticed a moisture
absorbtion line for polyprop.  Polypropylene absorbs moisture where as
polyethylene doesn't.  Although I am sure it is almost neglegible.


----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, July 31, 2000 8:06 PM
Subject: plate caps


> Original poster: "Metlicka Marc" <mystuffs-at-orwell-dot-net>
>
> hello eric, all
> i have built some fine plate caps using polyprop. sheet protectors,
> these i got from office max. they were Avery " diamond clear " units,
> these were the only ones that were made from polypropylene. office max
> gave me a discount for 1200 units.
> my caps were 42 plate units with 5-3.3mil protectors between each plate
> giving a total of 33mil dielectric per plate. i used al. foil for the
> plates but i would suggest al flashing if i to do it again, the foil was
> a lot of trouble to cut,flaten and smooth.
> since the sheet protectors were 8.5" by 11", each plate was 7" by 9"
> with a 3" by 1" tab sticking up from the corner for the attachment
> point.
> i built a form from plywood that i could stack the unit in,placing two
> very long big wire ties on the bottom then a polyeth. cutting board that
> i found at dollar store. after stacking 42 plates alternating the tabs
> side to side with five sheet protectors between each, i placed another
> poly cutting board then 42 more, another cutting board, 42 more.
> this gave me three caps of 42nf with a v rating low end guestimating at
> 500 v per mill, 16500v each. i sandwiched all these together with
> cutting boards on each end, then slid it into a new five gallon bucket
> with lid. i folded all the tabs up together then connected the three
> caps into series with hv wire and alligator clips, then i put brass
> bolts through the lid and connected the bank, this gave me a cap bank of
> 14nf-at-49500vac.
> i filled the bucket it mineral oil and let it sit for a couple weeks,
> putting a vacuum cleaner over the spout every day to suck out the air. i
> built to of these and paralleled them for 24nf.
> if you contact me off list i will send some pics.
> if i had to do it again i would use the party cup cap design that i sent
> you. placed into a 4" pvc pipe the cups are cheaper easier and perform
> well.
> if you still want to build the flat plater, i found a co. that sells
> 6mil polyeth. bags cheap. you can call 1-800-481-3600 for a catalog.
> hope this helps,  marc
>
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