Re: Series Connection of IGBT / MOSFET Switches - SSSG

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

Original poster: "David Sharpe by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

The point is that this series switch is "possibly" a replacement for a rotary
spark gap (async or sync).  Maximum PRF I've seen is 400Hz, point is
you charge a capacitor through the primary of your TC, then discharge
capacitor to PS return like an SCR in a capacitive discharge ignition.
Dwell times of up to 1mS to allow energy decay to '0' (or first notch)
can easily be accomplished.  Peak powers are still on "low" side for
a SG system (15kV -at- 1.5kA = 22.5MW +/- at maximum rating).

If you had a solid state switch that could reliably handle say 30kV with
up to 90% reversal at up to say 5kA (150MW peak), you'd have a
reliable SG replacement, but at a cost of >$50K in my estimation...

Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA

Tesla list wrote:

 > Original poster: "Black Moon by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
<black_moons-at-hotmail-dot-com>
 >
 > 10us?? gezus! thats forever man, 1us is 1mhz, 10us is 100khz max
 > that means for a 100khz coil it will ALLWAYS be in midswitch. and thats
 > assumeing by 10us you mean to switch on then off
 > if its just on/off time, that means its only 50khz.
 >
 > >From: "Tesla list" <tesla-at-pupman-dot-com>
 > >To: tesla-at-pupman-dot-com
 > >Subject: Re: Series Connection of IGBT / MOSFET Switches - SSSG
 > >Date: Mon, 04 Nov 2002 08:16:01 -0700
 > >
 > >Original poster: "Jan Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>"
 > ><jwagner-at-cc.hut.fi>
 > >
 > >Hi,
 > >
 > > > As a sidebar from the Chicago Power Electronics Conference,
 > > > I found this URL for an App. Note from IXYS concerning
 > > > applying IGBT's or MOSFET's in series for capacitive discharge
 > > > (OLTC) applications.
 > > >
 > > >   http://www.ixys-dot-com/t080698a.pdf
 > >
 > >Just curious, why isn't anyone considering GTO thyristors for this?
 > >ok they do eat a lot of gate current, and switching time is around 10us
 > >or longer, but, for "spark gap" replacement it should work very well. I
 > >mean, something like 4kV 3kA-continuous is possible. GTOs being older tech
 > >than igbts they should be comparatively cheap to get...
 > >
 > >cheers,
 > >  - Jan
 > >
 > >--
 > >*************************************************
 > >  high voltage at http://www.hut.fi/~jwagner/tesla
 > >  Jan OH2GHR