Re: Mot Question

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

Original poster: "sundog by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sundog-at-timeship-dot-net>

Hi David,

   Firstly, we forewarned that MOTs are positively *lethal!*     Usually 
their output is around 1800-2100v at upwards of an amp under a dead 
short.  Not what you'd want to get hit by.  That being said,

   MOTs typically have 3 windings.  There's the primary, usually a 
heavy-ish gauge magnet wire coil of fair size.  Very hard to miss.
   Then there's the secondary. This is usually the largest winding on the 
transformer, as big or bigger than the primary, depending on the MOT. It's 
wound with fine wire, and 99.99% of the time has a single spade terminal on 
it.  The other end is bonded to the core.
   Then there's usually a third winding, that consists of just a handfull 
of turns (5-12 turns) of heavily insulated wire of a heavy gauge.  That's 
the filament winding for the magnetron tube.  You can either cap off the 
ends of it with wire nuts, or remove it completely (being very careful) 
with wire cutters and needlenose pliers.  I usually remove mine, but it's 
not a necessity.

   The core of the MOT must be connected solidly to Ground to get any 
respectable power out of it.  A single MOT without a voltage doubler is 
much too low voltage to drive a TC.

Now!  I *DO* have a MOT that has 2 spade terminals on the secondary.  One 
outputs 2100v, the other outputs 1900v.  The 1900v tap I covered in clear 
silicon and ignore.  By feeding 12v into the primary of the MOT you can 
usually get a good reading of voltage on the output that doesn't exceed 
most meters (750v is a usual figure) AC input voltage.   That'll tell you 
what voltage the MOT can put out, but be careful, the HV leads usually end 
up around 175-220v off 12v input!

  Above all, *be careful!*  Use quality line cords and a good ground when 
working with MOTs, and unplug if you even think you may have to touch 
it.  Most of my MOTs pull between 8-10A shorted, and unless yours is an 
exceptionally well or poor made MOT, it should fall into that range.

  Hope it helps!

  Shad


At 09:17 AM 11/18/2002, you wrote:
>Original poster: "Harold Weiss by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><hweiss-at-new.rr-dot-com>
>
>Hello All,
>
>I picked up a scrapped out MO for the plasmatron experiment.  The 
>magnatron and cap were removed, but it still had everything else.  My 
>question is:  On the secondary there are two spade terminals. One measures 
>about 62 Ohms to the ground lead on the core.  The other seems not to be 
>connected anywhere, yet there is magnet wire soldered to it.  The 
>terminals are about 1/4" apart.  Which is the HV output?
>
>As this is the first MOT that I have played with, I want to know where 
>things are before applying power. Thanks.
>
>David E Weiss
>
>
>

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Shad (Sundog)
G-5 #1373
"Ever stop to think, and forget to start again?"
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