[Prev][Next][Index][Thread]
Re: oil capasitor
The oil is only "self healing" if it is continuously pumped
through a filter (1 micron) to remove the carbon particles
from a previous spark. The oil switch used on the 5MV
EMP pulser has to be contiouously pumped and even
then a short waiting time between shots is necessary to clear
out the carbon debries. Experimenting with an oil tester
,the first breakdown at .1" gap occurs at 39kV with clean
freshly filtered oil. The oil will only hold off about 20 kv
on the second application of high voltage. It gets lower each
time the voltage is applied.
Barry
----------
From: "tesla-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
To: Benson Barry; "Tesla-list-subscribers-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
Subject: Re: oil capasitor
Date: Saturday, December 14, 1996 4:24PM
<<File Attachment: 00000000.TXT>>
Subscriber: kukkonen-at-cc.hut.fi Sat Dec 14 13:09:44 1996
Date: Fri, 13 Dec 1996 22:28:50 +0200 (EET)
From: Kristian Ukkonen <kukkonen-at-cc.hut.fi>
To: tesla-at-pupman-dot-com
Subject: Re: oil capasitor
After reading all the discussion about a capasitor using
xformer oil as the di-electric I did a quick calc :
16 plates, 1000mm*300mm, 5mm separation, dec=2.0 -> 16nF
3mm thick plates: Al 39kg, steel 115kg.
between plates 24liters of oil.
IMHO, not at all that bad..
That aluminium of 40kg will cost about 800FIM = 170USD..
Transformer oil 25liters will cost about 250FIM = 50USD..
That capasitor with 5mm of oil SHOULD work up to several
dozen kVac.. Normal rating of xformer oil 30-80kV, with
30kV/mm -> 150kV rating and as it's self-healing the
rating doesn't need to be too conservative.. :)
The cost would seriously be reduced using steel instead
of aluminium for plates : 115kg for 230FIM=45USD and
3mm is an overkill - perhaps 1mm is enough -> 15usd..
The cost would only be 65usd.. Much less than for a
LDPE rolled cap.. Of course, this presumes that one has
got the equipment and materials for the oil tank
(welder+steel plate), HV terminals (from old poor pig),
spacers (ceramic or plastic plate, for free as scrap pieces)..
Steel is available in 1000*1000 pieces which can easily by
cut to 1000*300 pieces.
IMHO sounds like worth a try.. Much better than LDPE&SF6 :)
The trick question: what about the RF-dissipation factor of
the oil? Will it matter REALLY whether one uses Al or steel -
the thickness is only for rigidity of course.. Will this
be a poor performer? All the connections can EASILY be made
to be REAL heavy - spot welding etc..
Opinions, and especially facts, welcome!
Kristian.
---------------------------------------------------------------------------
| 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 |---------
----------------------------------------------------------- 42