Re: Polarized HV/ what's + and what's -

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "robert heidlebaugh" <rheidlebaugh-at-desertgate-dot-com> 

ELECTRONS TEND TO BE EMMITED OFF OF A POINT LEAVING A POSITIVE CHARGE BEHIND
. ELECTRONS TEND TO COLLECT ON A SPHERE BECOMING CHARGED NEG . THAT IS HOW A
CORONA POINT/CUP RECTIFIER WORKS.
    ROBERT    H
-- 


 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > Date: Sat, 07 Aug 2004 18:10:31 -0600
 > To: tesla-at-pupman-dot-com
 > Subject: Re: Polarized HV/ what's + and what's -
 > Resent-From: tesla-at-pupman-dot-com
 > Resent-Date: Sat, 7 Aug 2004 18:28:02 -0600
 >
 > Original poster: "Peter Terren" <pterren1-at-iinet-dot-net.au>
 >
 > I have done experiments of my own with
 > my 100 KV DC supply.  For electrodes I used a needle point copper wire and a
 > 5 cm brass sphere (well, a door knob actually).  The longest sparks were
 > with the needle as positive.  The readings that follow are spark lengths in
 > mm with
 > (needle pos:sphere pos and ratio).
 > 15:12      1.25
 > 53:41      1.29
 > 100:53    1.88   ie  47% difference
 >
 > Peter (Tesla Downunder)
 > http://tesladownunder.iinet-dot-net.au
 >
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Saturday, August 07, 2004 11:34 PM
 > Subject: Polarized HV/ what's + and what's -
 >
 >
 >> Original poster: "David Rieben" <drieben-at-midsouth.rr-dot-com>
 >>
 >> Hi all,
 >>
 >> I recently scored a pretty nice x-ray transformer. I think it's
 >> rated around 150 kV -at- ~ 600 mA. I've already repaired a
 >> carbon tracked phenolic rectifier mount twice. The new
 >> phenolic mounting block also carbon tracked after the
 >> first repair but so far the second repair has held up (keep-
 >> ing my fingers crossed). Anyway, I'm wanting to keep
 >> the rectifiers intact in this transformer since I'm wanting
 >> this one as a very high DC voltage source. Since I have
 >> it all back together after the last repair I really don't want
 >> to dig into the oily mess again just to get a close look at
 >> the diodes to determine the polarity of the HV outputs. I
 >> have heard that one polarity tends to form corona easier
 >> and actually arc further at a given voltage than the other.
 >> I've noticed this phenomena from the output leads of this
 >> transformer as I slowly ramp up the input voltage to it with
 >> a big variac. Of course I'm also seriesing the variac's out-
 >> put to it with a ballast assembly since x-ray trannies are
 >> NOT current limited. Anyway, I was thinking that the ne-
 >> gative terminal would be the one that would most likely
 >> tend to more corona and arc further at a given voltage
 >> but I simply can't remeber for sure. I think Antonio de
 >> Quieros was talking about this once. Can anyone tell
 >> me which polarity will form more corona and arc further
 >> at a given DC voltage?
 >>
 >> Thanks,
 >> David Rieben
 >>
 >>
 >>
 >>
 >
 >