MOTs in series

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

Original poster: "S & J Young by way of Terry Fritz <twftesla-at-qwest-dot-net>" <youngs-at-konnections-dot-net>

Ed,

I wonder about MOT insulation breakdown as well.  To reduce the core to
winding stress, I do the following:  For a MOT 4-pack, the outer MOT
secondaries are disconnected from the core.  I run two HV resistors in
series across each inner MOT, and the center connection of these resistor
pairs goes to the associated outer MOT cores.  This keeps the outer MOT
primary to core and secondary to core voltage at roughly half the MOT
voltage (about 1 KV), easily handled by the winding to core insulation
without the need for oil.

For those running 8-packs, it is amazing the outer MOTs don't flash over,
even when immersed in oil.

I would think one could salvage or make a large core, wind a husky 120 or
240 volt primary, and wind several well insulated 120 volt secondaries to
power outer MOTs and not worry about MOT insulation breakdown.

(I assume the "80 in series" below is a typo - should be "8 in series"?  If
someone has really done 80, please tell us how!)

--Steve


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, July 16, 2002 11:03 AM
Subject: Re: Why people don't use MOTs in a TC


> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
>
> Tesla list wrote:
> >
> > Original poster: "Ben McMillen by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <spoonman534-at-yahoo-dot-com>
> >
> > Hi Dan,
> >   If you run 6 - 8 in series (secondaries in series),
> > parallel the primaries, and immerse the whole mess in oil,
> > then you'll get near pole pig performance at a fraction of
> > the cost! (aka FREE!)
> >
> > I can't remember who, but someone here on the list has
> > successfully put up to 80  MOTs in series.. Before you
> > attempt this (if you decide to) make sure you do some
> > research on the setup.. a few of the MOTs have to be
> > slightly modified..
> >
> > Hope this helps
> >
> > Coiling in Pittsburgh
> > Ben McMillen
>
> Every time I read about MOT's in series I keep wondering about primary
> to secondary breakdown.  Don't see how this can be avoided, considering
> the construction.  Any other thoughts?
>
> Ed
>
>
>