Re: Re: Convert your MOT to NST?

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

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Good point. I don't know if any oil can actually get
inside the secondary winding. However, it can prevent
secondary to core breakdown. For reasons I have not
attempted to analyze, an oil bath seems to toughen up
a MOT quite a bit--sealed secondary or no.

Greg
http://hot-streamer-dot-com/greg

--- Tesla list <tesla-at-pupman-dot-com> wrote:
> Original poster: "Cory Roussel by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <imcuddlycory-at-yahoo-dot-com>
> 
> Hello,
> 
> 
> About your ideas- whoa- hold on, how would an oil
> bath
> work on a MOT??  The secondary turns seem way too
> tightly wrapped to fit any oil in... The insulation
> seems to make a fluid proof seal.
> 
> 
> Cory Roussel
> 
> 
> 
> --- Tesla list <tesla-at-pupman-dot-com> wrote:
> > Original poster: "Gregory Hunter by way of Terry
> > Fritz <twftesla-at-qwest-dot-net>"
> <ghunter31014-at-yahoo-dot-com>
> > 
> > Hi Steve,
> > 
> > I tried a similar experiment a few months back,
> and
> > got neat output sparks up to 1/3" or so from a
> > single
> > MOT. I don't know how much voltage that is, but it
> > is
> > certainly more than 2KV. Just for grins, I chopped
> > off
> > the primary and replaced it with about 50 turns of
> > 14AWG to increase the turns ratio. Stimulated by
> the
> > dimmer/cap combo, the modified MOT sprouted arcs
> of
> > about 1/2" to 5/8"--for a few seconds. Then it
> died.
> > I
> > could still hear it arcing somewhere. I'm sure it
> > was
> > inside the secondary or perhaps from the secondary
> > to
> > the core somewhere out of sight. Too bad. It
> > certainly
> > validates your principle though. Maybe I should
> try
> > this again with the MOT in an oil bath?
> > 
> > Spark On,
> > 
> > Greg
> > http://hot-streamer-dot-com/greg
> > 
> > --- Tesla list <tesla-at-pupman-dot-com> wrote:
> > > Original poster: "S & J Young by way of Terry
> > Fritz
> > > <twftesla-at-qwest-dot-net>" <youngs-at-konnections-dot-net>
> > > 
> > > Hi list,
> > > 
> > > MOTs are sometimes used to power TCs.  MOTs are
> > > typically free, don't break
> > > down like NSTs often do, and are good for 1 KVA
> or
> > > so.  On the downside, the
> > > 2 KV voltage is on the low side, requiring 2 or
> 4
> > in
> > > series and/or voltage
> > > multipliers, and the current is rather high,
> > making
> > > it tough to cool and
> > > quench spark gaps.  And their self-current
> > limiting
> > > (magnetic shunts) are
> > > not all that effective.
> > > 
> > > Can these limitations be overcome?  Yes, sortof.
>  
> > I
> > > tried an experiment and
> > > got around 10 KV out of one at reduced current -
> > > probably 100 ma or so
> > > average.  How?  By driving the MOT from a lamp
> > > dimmer and 15-30 mFd cap in
> > > series.  Same idea as driving an ignition coil
> for
> > a
> > > TSG, only with more
> > > input power.  The voltage is much higher than
> > normal
> > > because of the more
> > > rapidly changing magnetic field, and the average
> > > current goes down because
> > > power is applied for only part of a cycle.
> > > 
> > > The insulation of the MOT I tried did not break
> > down
> > > for output arcs that
> > > would bridge 1/4 to 3/8 inch.  It would be a
> good
> > > idea to immerse a MOT run
> > > this way in oil to improve its chances for long
> > term
> > > survival.
> > > 
> > > Using just a straight dimmer, the operation was
> a
> > > bit flaky, as others have
> > > reported in trying to drive an inductive load. 
> I
> > > didn't try adding a second
> > > triac, but I am sure that would improve
> > performance
> > > a lot.
> > > 
> > > So one can get NST-like performance out of a MOT
> > if
> > > driven in this unusual
> > > way.  A pair of them would be good for 16-20 KV
> at
> > a
> > > 100 ma or so, depending
> > > on the size of the series cap used (use motor
> run
> > > caps).
> > > 
> > > Just something to consider and tinker with if
> you
> > > are so inclined.
> > > 
> > > --Steve
> > >