Re: advice wanted for building MOT stack

["Tesla list" <tesla@xxxxxxxxxx>]

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

Hello Robert.

There is many advice regarding MOT-Stacks
in the archives, but here are my 2 cents:

Look for mots with good secondary to core clearance,
usually you will find better and not so good ones.
Put the "weaker" ones in the center and the better ones
on the outer sides of the stack. It is common to disconnect
the one end of the secondary which is connected to the core
and leave it floating, though with a 4-Mot stack you might
get away without doing so.


You can use ordinary hookup wire and feed it through
some tubing to aid insulation for the connections.
Connect the cores of the innermost MOTs together, connect
the HV out of the inner mots to the cores of the outer mots.
This way you can use 3 Terminals on the HV side, 2 outer
HV terminals and one central ground terminal, just like NST's do.
Make sure you get the phasing right, you can check that with
LV tests, but beware, even with only 12V in the output will
be high enough to give you a nasty zap...or worse.
You can remove the shunts, but this is not crucial, only if you
want to get every last bit of power. You may want to put them
under oil which aids insulation and cooling, but here, too,
you may get away with a "dry" setup if you avoid exessive
voltage rise or draw too much power for longer periods.

The voltage of a 4 Mot is not particulary high, so you may need
a bigger primary cap to take full advantage of the power handling
capability, which is relatively big.
So be very carefull, this is not a toy but just as dangerous as
a pole pig, they are sometimes called "ghetto-pigs" for a reason.

Hope this helped and play safe!
best regards

Christoph Bohr

> I am wanting to build a 4-MOT stack and I have never worked with
> MOT's before. I was wanting to know if anyone can give me some advice
> on building one of these things (what kind of wire to use for
> connections, how to connect the MOT's together ect.)
> Thanks in advance.
> Robert,