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Re: this cap made for trouble?
Moi Jan.
I haven't got a long experience in PE caps, but I built one and read a lot
about
those on the list. I got the feeling you'll end up noticing that:
- It's not so easy, it's not so simple
- you need more money than what you thought in the beginning
- the end result is no so robust/nice looking/usable (odd shape, oil leaks,
etc.)
- after some run, sometime, it will spark through: end of your capacitor :(
With a little more money you could build an MMC capacitor: at least you
know for
sure:
- what it costs
- when you'll have it ready and what you get
- that it works
And remember: no oil, no glue, no pumps, just welder and drill needed.
Call me if you want to talk more about it: 050 353 9468
Regards
P.S. PE cap gurus, please correct me if I'm wrong!
Tesla List <tesla-at-pupman-dot-com> on 19.12.99 05:39:56
To: tesla-at-pupman-dot-com
cc: (bcc: Marco Denicolai/MARTIS)
Subject: this cap made for trouble?
Original Poster: Jan Florian Wagner <jwagner-at-cc.hut.fi>
Hi,
about to turn from a TV flyback powered TC to something bigger during the
holidays... The problem is now the tank capacitor, and I'd be very happy
if someone could tell if I'm heading into trouble / a bad cap with the
following ideas.
I've made some tests with plastic bags (PE), and ordinary transparency
sheets (like those you write on, not those for printer/copier), and both
seem to stand 3kVAC very well. No clue about RF properties though. :o)
So, this is what I had in mind:
- a couple of transparency sheets stacked up, with
household aluminium foil in between. goal is 10nF for 8kVAC
- aluminium foil folded twice or more often
- using the 10nF caps, a 4x4 cap array to be powered
by a 8kV 50mA NST (200W/400VA, cos(phi)=0.5)
- thin layer of liquid paraffine oil between alu & transp. sheet
during assembly, later whole thing immerged in paraffine oil
Does this sound ok?
I think that the transparency sheet will stand the strain, but not so sure
about the aluminium foil... What type of foil is used in commercial HV
pulse caps? Any thicker than household alu foil?
Many thanks in advance
- Jan
--
*************************************************
Jan Florian Wagner
jwagner-at-cc.hut.fi, petwag-at-kolumbus.fi
http://www.dsh.edu.hel.fi