Air as di-electric

To: tesla-at-pupman-dot-com
Subject: Air as di-electric
From: Kristian Ukkonen <kukkonen-at-cc.hut.fi>
Date: Fri, 3 Jan 1997 01:38:57 +0200 (EET)
Subscriber: kukkonen-at-cc.hut.fi Thu Jan 2 23:04:23 1997

I've lately been seriously thinking about spending some valuable
lab space for a "definitely-not-space-efficient" capasitor. The
good this would be the fact that it could be virtually impossible
to destroy without melting steel BIG TIME..

So, it's a plate-cap using steel plates separated 10mm from each other.

It would mean that the capasitance, using 2000mm*330mm plates would be
0.5841nF *(n-1), where n is the amount of plates.  Using just 41 plates it
would be about 23nF. using 1mm thick plates the total mass would be about
200kg. The cost would be 45FIM (9usd)  for a plate 1000mm*2000mm which
would get converted to 3 plates.  This would mean 14 of those big plates
and 630FIM (130usd) - propably less - usually price for steel is 2FIM/kg
at "surplus"stores.

The total size of the thing would be 2m*.33m*.41m "only".
Plus the fixture keeping the thing intact.

Quite reasonable. Does not require much FLOOR space. :)

Would be (trans)portable and moveble with some wheels under it.

So, the question is: dry air etc. break at something like 4kV/mm. That
would mean 40kV rating for that monster. Thinking reasonably it could
work with the 20kV pig I have.

In reality? Does someone out there know? for sure?

At least it would be INDESTRUCTABLE.

Adding a blower below the thing would make any arcs act like in a jacob's
latter - and I could actually put kind of jacob's ladders to the top of
the plates - between each pair of plates. It would quench any arcs caused
by cap "breakdown". 

So, before buying those plates of steel and starting to spend some disks
with the disk grinder cutting plates to pieces and sending molten pieces
of steel around: 

Opinions? Am I forgetting something? Will there be HUGE corona between
plates - causing losses and breakdown at much less than 4kV/mm ? Something
else? I may need to put some plates of plexi between edges of plates..

It could be made tunable by inserting pieces of plexi (or PP) between
plates..

I could build a tank around it too - and fill it with dry N2 or
something fancier. It would make it a potential bomb though.

Thanks,

  Kristian.

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| Kristian Ukkonen       |  Do as thou wilt shall be the whole of the law |
| kukkonen-at-alpha.hut.fi  |_____  Chance favours the prepared mind  |-------
| http://www.hut.fi/~kukkonen |  Fear is the mind-killer  |---------
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