Re: MOT Power Supply Questions

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

Original poster: "Finn Hammer by way of Terry Fritz <teslalist-at-qwest-dot-net>" <f-h-at-c.dk>


 >  > Original poster: "David Speck by way of Terry Fritz 
<teslalist-at-qwest-dot-net>"
 > <dave-at-davidspeckmd-dot-org>
 >  >
 >  > Simonas,
 >  > As I understand three phase circuits, the best you would get from this
 >  > arrangement is about 4400 volts, or about the voltage of two MOTs in
 >  > series.  You would get 3X the current capability of one MOT pair, and 
less
 >  > ripple on the DC because of the three phase advantage.
 >  >
 >  > To get 6 x 2200 volts out, you would have to have all 6 transformers 
lined
 >  > up in series so that the peak voltage would be reached in each 
transformer
 >  > simultaneously.  That will never happen in your three phase star
 > arrangement.


David, all

In a 3 phase system, the phases are 120 degtees apart.
You can get the highest voltage out of the transformer by connecting the
phases in a star, or wye connection, since there are 2 windings in
series btwn. each outlet.
The maximum voltage does not appear when one of the phases peak, rather
when one phase is 30 degrees before peak, and another phase is 30
degrees after peak. (the 3rd phase is then at zero.

At this time, the output is 2*cos(60deg)=2*0,8660=sqrt3
Now rectify and smooth it, and you have that, multiplied by sqrt2=1.41

So with 4000volts on each transformer, the full voltage is
4000*1.41*1.73=9798V

Please view in a fixed-width font
         such as Courier.




                       c   ----+-
                      c        |
                     c         |
                    c      0.8660
                   c
                  c            |
                 c             |
  ccccccccccccccc    ----------+-
                 c             |
                  c            |
                   c
                    c      0.8660
                     c         |
                      c        |
                       c ------+--
Cheers, Finn Hammer