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Re: Sold state IGBT disruptive coil spark gap idea

Original poster: dest <dest@xxxxxxxxxxxxx>


guys - are you crazy, or just very lazy? % ) like "Lau, Gary" said on
9 Aug 2005 - "I hate to propagate this never-ending thread that has no
relationship to its subject line, but..." : )))

> Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

>>Maybe the special glyptol coating he uses permits him to
>>tighten his coupling far beyond what most folks can achieve
>>without getting racing sparks.  Maybe this is what has permitted
>>him to see what others have failed to see.

> The coatings, I think, are used more for "every day" durability.  I
> doubt he is running so hard as to depend on the coating for voltage
> stand off...

of course coating has nothing to do with preventing racing sparks -
"This secondary had a very heavy coat of the good ol' Behr Super Build
50 product on it and it didn't help at all."
imo those sparks had more to do with harmonic structure of secondary
voltage. i`ve seen concept of "folded resonator" in the archives, and M.W.
even was intended to analyse it, but it is more than a couple of months
passed since that post with no further news from him.
Terry - i know that you already has made a huge number of various
msmts of sec V and I - have you tried to make spectrum analysis of it?
it must be extremely simple to nail this problem down with suitable
equipment, isn`t it so? im only reading of june '98 currently, so plz
don`t kick me too hard if all this was answered in the past % )

>>Some coupling measurement methods
>>give incorrect results, making the coupling appear tighter than
>>it actually is.  This is especially true at tighter couplings.

> Coupling can be calculated easily within a percent or two with
> computer programs and knowing the exact dimensions...

c'mon guys! don`t calculate - just measure it, coz even a kid know how
to make correct msmts these days : D

"Apply as much 60Hz AC current to the secondary as it will comfortably
take (consult wire tables). Measure the 'open circuit' voltage of the
primary. The mutual inductance M = Vp / (Is * 377), derived from
Vp/Is = 2*pi*F*Lmutual.
I usually omit the variac, and just throw 120 volts across the secondary,
which yields about 0.25 volts RMS on the primary for k=0.15 .
It's a quick measurement method, with about a 1% accuracy in my case."

k = M / sqrt(L1 * L2)

You would need tens of MV to break 1/4" acrylic.
20-05-1998 (c) Antonio Carlos M. de Queiroz