Re: MOT PS

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

Original poster: "Mike Nolley by way of Terry Fritz <twftesla-at-qwest-dot-net>" <nolleym-at-willamette.edu>

> You'll get twice the power out from the 4 MOT configuration.  The voltage
> doubler is essentially a half wave rectifier, that is, although the output
> voltage is doubled, the output current (for the same transformer) is halved.

    There may be some confusion about which 4 Mot supply is being referred
to.  The 2 stage
configuration (with the second stage being driven at 2X the voltage through
the secondary
winding) tends to blow up fairly quickly if not submerged in oil.  There is
an alternate 4 Mot
set up which I have been working on which works just as well, without the
need for the oil.
    I'm using 4 large Mots, each capable of 2-3kw.  Two are out of an
industrial microwave oven
and the other 2 are the large Toshiba type.  I can't draw a schematic, but
essentially it is
just 4 voltage doublers arranged so that a positive and negative firing
happen on each half
cycle.  This lessens the filter capacitor requirement and also insures a
very robust power
supply.
    My only problem is that with 8 uf on each of the 4 legs, it instantly
blows the breaker ;
).  (This is also due to the fact that I removed the shunts).  If I ever
choose to run it at 10
kw I could up it to 15-20 uf per leg I imagine, and stick a fan on it.....
    But in the short term I'll probably just have to ballast it.  I might
get web pictures up
soon--it fits nicely into an old snare drum case, though it weighs 75lb.
Another cool thing
about it is that I have arranged a set of switches so that I can alternate
between 500V, 1kv,
2kv and 8kv operation by switching the primary taps between a "hot" and
"ground" bus, and each
other for 500V.
                --Mike