MOT question

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

Original poster: "Allanh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>

I have two MOT's in series producing 3500 VAC. If I
don't use any ballast, I get flameouts at the spark gap.
I've tried using the primary of a dead NST in series with the MOT'S but all
I get is a smaller blue spark and almost
nothing out of the TC. Any suggestions?

allan

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, December 04, 2001 7:08 AM
Subject: Re: Choke Chat


> Original poster: "Michael H Nolley by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <nolleym-at-willamette.edu>
>
> >  I could use easy-to-wind round bobbins.
> > I would wind these with about 5000 turns each of 28AWG
> > and use one choke on each leg of the DC PSU output. I
> > have no idea how to estimate the inductance of such a
> > choke. I'm thinking I would drive the thing with two
> > series MOTs for 4kvac into a full-wave voltage
> > doubler, and use the chokes to bump the resulting
> > 12kvdc to roughly 20kvdc.
>
>     The problem with the straight core idea is that the resulting
> inductance is less than if a
> transformer core or "closed" core is used.  The Mot is ideal in this case
> because it is already
> there--i.e. you already have the core in place.  It is no problem to
remove
> the primary and add a second
> secondary in series, since the primary isn't being used anyway.  This
> doubles the inductance and gives
> you about 4000 turns.  A couple of these would be plenty I would think.
> You'd need to grind off the weld
> beads on 4 Mots, but this is surely easier than a homebrew core IMHO.  To
> avoid saturation, you could gap
> them, or use fairly massive cores--the former probably being the best
> solution.  Once the weld beads are
> gone, gapping the core is easy:  just space with strips of thin plastic
> (overhead films, perhaps) and
> re-assemble using hardware store screw clamps.
>             --Mike
>
>
>