Re: DIY HV transformer

["Tesla list" <tesla@xxxxxxxxxx>]

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

Hello all.

I just wanted to give an update what happened today:

Of course those of you who blamed the steel in the bolts
that creates eddy currents were right. I replaced them with
brass ones and the problem disappeared.

But the behaviour of the transformer over all did not change,
maybe 2 amps less current draw.
I tried to use PFC, but the 80µF I had did not do anything.
On a Jakobs ladder or short circuit the transformer would
deliver 200mA at full input voltage while the input current
skyrocketed to 25Amps.... This did not look verry impressive
and the arc on the jakobs ladder sounded wimpy and would
not even rise....
I thought I'd give it a try with my TC, still without oil and reduced
130V input voltage. I had to completely readjust the RSG that
was set for use with the MOT-Supply but then the thing sprang
to life. Current draw was 13A at 130, safety gap fired occasioinaly
while set to around 12KV(!)... After rising the input voltage even more
the secondary arced over to the core and I turned off ...
The wire was melted in the point where the arc struck, but luckily
only at the end of the outermost winding. After removing  4 demaged
turns everything looks fine again..... huh, close call.
After all, though measurements predicted something worse it seems
it will at least run at all.... but further optimization is indicated.

Thank you all who contributed.

best regards

Christoph