Re: Convert your MOT to NST?

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

Original poster: "J Whyte by way of Terry Fritz <twftesla-at-qwest-dot-net>" <xoom321-at-hotmail-dot-com>




>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Convert your MOT to NST?
>Date: Tue, 22 Jan 2002 20:18:53 -0700
>
>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
>
-----------------------------------------------
Why not link 4 LARGE SIZED (120VAC) MOT's in series and throw 240VAC at it? 
I have gotten good performance UNDER OIL!
~voltages are well past 15kV at high mA (probably 400 mA or so)!!! 
SECONDARIES ARE HOLING UP FINE!

MOT's ROCK

JW


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