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>

Simonas,

I take it that you intend on running secondary"s in series, primary`s in
parallel.
To avoid having to measure at excessively high voltages:
With the secondary`s connected to the mains, or a low voltage
transformer, check with a scope that primary and secondary are in phase.
Chose one wire from each set of windings, and mark them as "0",
"neutral".

Now, on the primary side, connect all neutrals to mains neutral, the
other 3 wires to each phase.

On the secondary side, connect neutrals, and take the juice out from the
other 3 wires.

It would be nice to have a 3-phase variac to ramp up voltage slowly,
would it not:

http://www.helmut-singer.de/stock/936192399.html

http://www.helmut-singer.de/

Hope this helps, Finn Hammer

Tesla list skriver:
 >
 > Original poster: "Simonas by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<rasim-at-takas.lt>
 >
 > maybe I've not explained it clearly:
 > Two MOT's are in series on each phase, giving ~4kV AC per phase. After
 > rectifier, summing all three outputs and placing smoothing capacitor there
 > should be 4kV times sqrt(2) times sqrt (3) output.. which is about 10kV DC
 > ...
 > Problem I encountered is when connecting MOTs in series one have carefully
 > phase both primaries and secondaries, in order to get double voltage and not
 > MOTs canceling each other out.. That I did, So now I have three pairs of
 > MOTs providing each ~4kV AC.
 > Question is, how to check relative phasing of them all before connecting
 > whole thing to 3 ph. ?? As I'm using unprotected connection to power company
 > (no brakers, no watt meter) I don't want to mess around with 3 phase and
 > incorectly connected 6 MOTs..  :):)
 > I measured current having them connected all to one phase, with pairs of
 > course not in star configuration, just left opened,  and it already draws
 > some 15A with voltage being 220V..
 >
 > if anyone would help me find solution that would be great ;) My 10kVa (I
 > hope to squeeze 10kVA out of those 6 MOTs ;):))  model is just about to be
 > finished, lacking only rotary and charging reactor not completely wound..
 > BTW what spark lenght I could expect?
 > thanx for answers.. ;)
 >
 > Simonas
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Wednesday, April 02, 2003 4:26 AM
 > Subject: Re: MOT Power Supply Questions
 >
 >  > 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.
 >  >
 >  > HTH,
 >  > Dave
 >  >
 >  > >Hiall,
 >  > >
 >  > >has anybody ever tried following configuration for DC tesla coil? :
 >  > >3ph outlet, 6 MOTs, 6 HV diodes
 >  > >2 MOTs connected in series and those 3 pairs in star configuration..
 >  > >in theory there should be 10kva 10kV power suply..
 >  > >
 >  > >I've just built one, but have trouble correctly phasing secondaries of
 > each
 >  > >MOT..
 >  > >
 >  > >Simonas
 >  >
 >  >
 >  >
 >  >
 >  >
 >  >