Re: SISG first sparks!

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Greg,

At 05:28 PM 5/16/2006, you wrote:
> Hi Terry,
>
> Over here in Australia we don't have the blessing of high current
> single phase feed lines to our houses, though I did manage to convince
> someone to install a 40A single phase line :). Those of us wanting to
> run large machinery, etc (me), instead are able to have 3-phase
> installed - a technically better, more efficient system then what you
> US guys have, but not so good for conventional large TC use. This has
> always been a nuisance, but maybe now it will be an advantage.
>
> I'm contemplating the construction of a 6-pulse rectified 3-phase
> supply using the vast array of MOTs I have lying around, which would
> suppply DC relatively free from ripple (note, i say relatively free -
> about 14% ripple). If I use two series MOTS (centre tap removed) on
> each phase, and assuming I extract the full interphase voltage, we are
> looking at about 10kV DC.

I think I would need a picture, but any way you can get high voltage 
DC at a reasonable power level should be fine.


> I'm wondering how you predict the SISG would perform in this scenario?
> I assume it would work fine, but probably at 300BPS?

IGBT heating is directly proportional to BPS.  The heat is low but 
another person is going to run at maybe 460 BPS.  Those boards have 
room for larger heatsinks.  I think he is going to offer them for 
sale real soon.  Of course you might run larger IGBTs too.  One 
should figure out the RMS and peak currents through the SISG for real 
high powers like that.

Rell.com apparently really does have 7000 of the IGBTs I use in 
Singapore. :-)))

> Finally SSTC
> design has become simple enough for anyone to make, probably with
> little to no test equipment - and at high power levels too!

:-))

Cheers,

        Terry



> Greg Peters
> Department of Earth Sciences,
> University of Queensland, Australia
> Phone: 0402 841 677
> http://www.hot-streamer.com/greg2
>
>
>
> ----- Original Message -----
> From: Tesla list <tesla@xxxxxxxxxx>
> Date: Saturday, May 13, 2006 10:52 am
> Subject: SISG first sparks!
> > Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>
> >
> > Hi,
> >
> > I wired up some odds and ends and put the gap on a coil:
> >
> > http://hot-streamer.com/temp/SISG-006.jpg
> > http://hot-streamer.com/temp/SISG-007.jpg
> > http://hot-streamer.com/temp/SISG-008.jpg
> >
> > The firing voltage is 1800V and it is running about 60BPS.  The
> > arc
> > to ground is 5 inches.
> >
> > The coil is 150kHz and the primary cap is 150nF so the bang energy
> > is
> > 0.243 Joule.  So its about 14.6 watts.  The old IGBT got just
> > barely
> > warm and the new one stayed cool (no heatsinks).
> >
> > This system was very far from optimal, but it did make nice sparks
> > with the new gap ;-))  When I get a lot more IGBTs, I can run it
> > at
> > 100 times the power ;-)))
> >
> > Cheers,
> >
> >       Terry
> >
> >
> >