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Re: Figure this out.

In a message dated 97-01-24 01:35:44 EST, you write:

> By the way, David, you mentioned that you put it into a
>  Plastic Case... Did you even HAVE a Case to Ground? Did you attach a
Ground
>  to the Core?

I removed the case before immersion in the paint thinner with a cold chisel
and then put the remaining lump of tar and steel into the freezer overnight
to harden the tar which I then hammered off in large chunks (attempting not
to dammage the windings in the process).

The typical construction of larger neon transformers is such that the inside
(or bottom turn of each of the neons (2) secondaries is run along the core
and soldered to it at several points and right through the middle (inside) of
the neon's primary to the opposing secondary on the other side of the core.
 In case the preceeding explanation is unclear, the neon's construction looks
like the following (the stars{*} are to indicate the HV leads/terminals and
the dashes {---} are to indicate the wiering connection which runs between
the two inside windings of the secondaries through the middle of the
primary).  The primary is in effect wound on *top* of the secondaries
connecting wire.

**[secondary]----[-p-r-i-m-a-r-y-]----[secondary]**

Because of this configuration, it would be virtually impossible to isolate
the secondaries inside turn form the core without completely dissasembling
(delaminating) the core and rewiering it.  And, once its under oil, all the
extra work that this would entail seems to be completely unnecessary.

>I wonder if the Neon Transformer companies could be persuaded to sell us
>Neon Transformers BEFORE THEY PUT THE TAR IN THE CASE?

No. All the ones I have asked so far could not be persuaded.  The cited
insurance liability and production disruptions as the two major reasons.

>Could it be that the oil bath is ALSO insulating the
>Primary to Ground and Ground to Secondary stuff TOO?

Yes Im shure that it is.  Any point at which arcing and breakdown might occur
is reduced or eliminated.  To be more specific, I believe that the most
 ypical problems (95%) with neons are two fold:
1)  Heating, which causes the tar to melt and flow away from the hot spot
(whether it is near the grounded core or simply between the layers of
windings). Which leads to:
2)  Carbon tracking, which may develope due to air bubles in the tar at time
of manufacture or because of heating (per above) causing voids of tar (air
pockets) during to operation.  This allows corona/arcing and carbon tracking
to develope wich then effectively shorts the secondary to either the case
(ground) or another winding. reducing or eliminating its output.

P.S.  I have also tried out a transformer form Sanyo that is filled with a
polyester substance rather than tar and it seemed to work well durring the
time I tried it out.  It is claimed by the manufacturer that the polyester
substance wicks the heet away better than tar and has a much higher
dielectric strength.  It was not, however, vacuum impregnated like the
secondary from Newtown and so has more and larger air bubles  in the
substance which would likely be more of a risk for breakdown. (still better
than the tar I'm shure).

-DavidF-