Re: MOT power supply

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

Original poster: "Steveh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <steve.g.hall-at-attbi-dot-com>

Mark,

I don't think it would be possible to run a typical 120V MOT at 240V. I did
some analysis on a few of my MOTs. By measuring the cores cross sectional
area and counting the number of turns on the primary, it is a simple matter
to calculate the flux density. The result was 20,000 gauss for all of my
MOTs. This happens to be the absolute maximum flux density for typical
silicon-iron used in transformer cores. This was no surprise, MOTs are
designed with one goal in mind - CHEAP!
In other words, a typical MOT is on the verge of saturation at its intended
input voltage. Increasing the voltage much beyond 120V will result in large
amounts of current being drawn with little increase in output voltage.
You could, however, connect two MOTs together with the primaries in series
and the secondaries in parallel, observing proper phase, of course. This
would allow you to use 240V for power. I also don't see any reason why one
couldn't connect larger numbers of MOTs together in a similar fashion. Even
numbers would be used with primaries series connected in pairs, multiple
pairs would be paralleled. The secondaries could probably be wired in pretty
much any combination of series/parallel for the desired output current and
voltage. It would probably be best if all transformers were identical, but
that may not be an absolute requirement.
Any thoughts on this?

Steve
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, November 15, 2002 9:05 PM
Subject: MOT power supply


 > Original poster: "Mark Rossman by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<marossma-at-oakland.edu>
 >
 > Has anyone built an MOT power supple with an imput voltage of 240v  with
 > transformers that came from a 110 volt microwave. Im assuming that the
 > primary windings could easily handle the higher voltage, but i thought id
 > ask before i hooked it up.
 >
 > Thanks a lot
 > Mark
 >
 >
 >