Re: DIY HV transformer

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Christoph Bohr" <cb@xxxxxxxxxxxxxxx>

Just another update:

I reassembled the core  today, made new,
thin insulating paper sheets for the gap and
installed a terminal block for the primary
connections and ground connection.
Picture can be seen at bottom of page:
http://www.luebke-lands.de/tesla19.html

I ballasted the transformer with an opened
small MOT core rewound with 160turns of
stranded wire ( too thin because of space limitations )
which limited the current draw to around 20A.

Performace at full input voltage was pretty good and
no flashover occoured, though the transformer is
still not under oil, but this is jet to come.

One strange thing happened several times. After running
smooth for a minute or two, the transformer as well as
the variac started humming and current draw increased to
30A. This effect lasted for one or two seconds, then disappered.
Every once in a while it reappears, even at different variac settings.
Maybe some kind of resonance I suspect.....

Now I have to find an suitable container for an oil bath
( which is harder than I thought, I want to keep it small )

best regards

Christoph