Re: PDT (Pig) failure modes

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

Original poster: "Godfrey Loudner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ggreen-at-gwtc-dot-net>

Hi Dave

I had a similar problem with an old 7.5kVA industrial 120/240/480
transformer. By paralleling the two 120 windings, I could get up to 60 amps
at 120 with a 240 feed. This was a great high current supply for playing
around with MOTs. One day the transformer went on a dead internal short and
the breakers tripped. The next day I was very surprised that the transformer
was working, but it shorted again after awhile. I decided to scrap the
transformer for the nice heavy copper wire. After much agony, I finally
freed the winding from the core. Upon removing the top layer of paper, I
could see burn marks between two adjacent turns. I think that heat expansion
would eventually push the two weak spots together, and after cooling off the
weak spots would separate. Maybe something like this is the problem with
your pole pig.

When I got my pigs from T&R, I was told that they were under guarantee for
one year for normal usage. I forgot to ask if tesla coiling was considered
normal.

Godfrey Loudner

> What is truly a mystery about this thing is that it either works
perfectly,
> or acts like there is a crowbar dead short across the primary.  Well, at
this point, I'm tentatively pronouncing Ariel dead. I'm going to
> call T&R to see if they can supply a replacement core so that I can
perform
> transplant surgery.
> Dave H