Re: MOT Power Supply Questions

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

Original poster: "Peter Terren by way of Terry Fritz <teslalist-at-qwest-dot-net>" <pterren-at-iinet-dot-net.au>

Captain,
I've used 4 MOTs for 5 KW under oil for some time and get 6 foot arcs with a
six inch coil. See http://members.iinet-dot-net.au/~pterren/  Also comments
below.
Cheers Peter

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, April 01, 2003 9:07 AM
Subject: MOT Power Supply Questions


 > Original poster: "Mccauley, Daniel H by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>
 >
 >
 > I'd like to build a MOT power supply and had a few questions.
 >
 > 1.  I am going to use 4 identical MOTs wired in series.  Does anyone have
 > the proper hook-up diagrams for doing this "the best way."  I assume we
want
 > to wire the middle two MOTs referenced at ground and then have only one
 > transformer at either side floating at 2400VAC.  Also, I seen some
diagrams
 > where it appears they use two MOTs (opposed) to provide isolation for the
 > 120VAC input.  Any reason why they are doing this?  It doesn't appear to
be
 > implementing any type of ballasting.

That's how I do it. I don't use isolating MOT's.

 > 2.  Regarding current ballasting, what is the current trend.  Do we remove
 > all shunts from the MOT or can the MOT with the shunts still installed
give
 > us the current we need. (oil submersed)  Also, anyone have luck in running
 > these things to the max (under oil) without any ballasting at all???  I
 > think someone before stated that these things will self-limit the current
at
 > a point where operation (without total destruction) is possible.

I don't ballast but you could use 2 paralleled MOT's with outputs shorted in
series with the 4. I run over 20A at 240V (I'm in Australia) when on full
with a big tank capacitor.

 > 3.  These MOTs will be submersed in mineral oil.  What type of enclosures
 > (readily available) have you guys had luck with?  Anything off the shelf
 > that works extremely well???

I use transformer oil and a plastic rectangular storage box but with a ledge
inside the lip so I can drop a sheet of acrylic in which prevents splash
when transporting. Probably weighs about 40lbs all up and is easy to lift.

 > I'm hoping to get at least 5-6kW from this thing.  (Fingers crossed!)

Easy.

 > MOTs are a new thing for me, so any help is appreciated!
 >
 > Thanks
 >
 > The Captain
 >
 >
 >
 >