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Ballasting ..... Again



G'Day World,

I've been a bit quiet of late ....... busy ...... winding ... winding ...
winding .......

My 5 kVA transformer is nearing completion.  Wound up using 0.71mm wire for
the new secondary.  Needed 19 layers/winding to get 60:1 and 14.4 kV, but
due to thickness of insulation etc the window will only allow 18 layers
.... still, 13.6 kV will do just fine ;-)

While I have lost a few volts, I suspect the heavier wire/insulation will
pay for itself in the long run.

Anyhow, I digress......

The point of the post is to discuss ballasting this monster.  I have a 15A
variac, which will limit me to 3.6 kV theoretically (though I could
probably squeeze a little more for short runs).  I have a quantity of
left-over wire from the primary (it had windings out to 440V - since
removed) which I could use for an inductor with an appropriate core.  This
wire is rectangular and about 3.5 x 2mm .... quite heavy !

I have noted the multitude of posts on using welders (which I don't have
.... but could acquire if required).  Also the debate on using/not-using
series resistive elements.

The local 'junk shoppe' has some 20A variacs which I could skuttle.  If I
wound an inductive ballast on one of these how many turns would I need for
say 5, 10, 15, 20A steps ??

I also noted with *great interest* the comments suggesting no difference in
performance with slotted vs non-slotted cores - obviously not having to cut
the core would save a lot of effort.

I want to GET THIS RIGHT .......... having spent many hours winding this
toy, I don't want to see it go up in smoke !!

Thoughts, advice etc welcomed.

Cheers,


Mark

Tesla Page <http://www.cobweb-dot-com.au/~dkfinnis>