[Fwd: OLTC update]

["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>

Terry wanted me to forward this to the list while he is sleeping...

The OLTC thing is getting bigger...MUCH BIGGER, then anyone
would have predicted.  Like dynamic tuning by controlling how
many IGBT's are switching (controling the tank C).  Would
now require the CEEC structure I mentioned in a previous
post to allow bidirectional isolation.  The IGBT / capacitor
structures can now be modularized for plug in into busbars
from primaries, which is exactly the same design feature
used on high power Klystron drivers for linear accelerators.

Another point is potentially (no pun) scale up to truly enormous
power capabilities.  Now if we could just get the voltages up,
so we could reduce tank losses (i^2r and proximity)...

Best Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA
Return-Path: <twftesla-at-qwest-dot-net>
Received: from mx05.mrf.mail.rcn-dot-net ([207.172.4.54] [207.172.4.54])
          by mta04.mrf.mail.rcn-dot-net with ESMTP
          id
<20020811044326.ULHU385.mta04.mrf.mail.rcn-dot-net-at-mx05.mrf.mail.rcn-dot-net>;
          Sun, 11 Aug 2002 00:43:26 -0400
Received: from dnvrpop8.dnvr.uswest-dot-net ([206.196.128.10])
	by mx05.mrf.mail.rcn-dot-net with smtp (Exim 3.35 #6)
	id 17dkZe-0002qO-00
	for sccr4us-at-erols-dot-com; Sun, 11 Aug 2002 00:43:30 -0400
Received: (qmail 70696 invoked by uid 0); 11 Aug 2002 04:43:26 -0000
Received: from unknown (HELO 2x400mhz) (63.229.238.61)
  by dnvrpop8.dnvr.uswest-dot-net with SMTP; 11 Aug 2002 04:43:26 -0000
Date: Sat, 10 Aug 2002 22:43:49 -0600
Message-Id: <4.1.20020810222127.00a23fc8-at-pop.dnvr.qwest-dot-net>
From: "Terry Fritz" <twftesla-at-qwest-dot-net>
To: "David Sharpe" <sccr4us-at-erols-dot-com>
Approved: twftesla-at-qwest-dot-net
X-Sender: twftesla-at-pop.dnvr.qwest-dot-net
X-Mailer: QUALCOMM Windows Eudora Pro Version 4.1 
Subject: Re: OLTC update
In-Reply-To: <3D55E0C2.32751EEC-at-erols-dot-com>
References: <4.1.20020810212426.00a1da80-at-pop.dnvr.qwest-dot-net>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
X-Mozilla-Status2: 00000000

Hi Dave,

At 11:57 PM 8/10/2002 -0400, you wrote:
>Terry
>
>AWESOME!!!  You just made a self ballasted current source
>where the currents are dependent on the statistical manufacturing
>tolerances on capacitor values.  What modeling I've done suggests
>that 5% tolerance are acutally within 1% when taken as a grand
>average.  Need to scale up or drop frequency lower (or dynamically
>tune the system!!!!   :^)  ) Adjust the number of active IGBT's on
>the fly.  You're right, I'm crying with you.  :^)

Oh God!!!  Your right, you can tune the darn thing too by just "selecting"
cap strings!!!!!!!!!!

Also, there is no limit to the number of IGBTs in this method.  So a 300uF,
or whatever cap, with a big number of IGBTs is practical!!!  What!!!  Like
50,000 amp primaries :-)))))  Suddenly, there is no limit to the power...
:o)))))))))))))  We could scale it up till the breaker box blows off the
wall :-)))))))

>
>BTW this concept is similarly used with inductors to tie together
>very large bridge converters for large (100kW to 1MW+) SS Induction
>heating appartus.  Lumped inductors in load then become part of
>total tank circuit, and FORCE current sharing similarly to caps in
>this application.  I can find URL with this application in it to illustrate
>my point...

Yep! It's not a new concept.  I have used it to do current measurements on
MMCs when I didn't have the ability to measure the full current.  I just
did one string...

>
>Excellent, now sleep on it, but I wanna see it FIRE!!!

Yep!!  I sleep a lot, but still not enough to handle all this :-)))

I "thought" this may be "cool", but I never knew it was a "big thing" ;-))
Think we can obsolete variacs and transformers (NSTs, MOTs, and even PIGs)
like we did them oil filled homemade poly caps :-)))

Cheers,

	Terry


>
>Regards
>Dave Sharpe, TCBOR
>Chesterfield, VA. USA