Re: SSTC idea

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

Original poster: "chris swinson by way of Terry Fritz <teslalist-at-qwest-dot-net>" <exxos-at-cps-games.co.uk>


DRSSTC ?? Whats that all about, is there anything online which explains the
idea behind it ? It sounds interesting for sure!

Cheers,
Chris

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, March 18, 2003 12:58 AM
Subject: Re: SSTC idea


 > Original poster: "jimmy hynes by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<chunkyboy86-at-yahoo-dot-com>
 >
 >
 > This is the most interesting part of coiling to me. It's is not easy to
 > understand, and you can't look up the answer in a book.  I have been
having
 > trouble getting the drsstc running, mostly stupid stuff like bad
 > connections and shorts to the heatsink. I was trying to run the gates with
 > no dead time but there was enough stray inductance that the  shoot through
 > caused a big enough spike to blast the freewheeling diodes. This week I'm
 > adding separate gate drivers, because the turnoff is 1usec slower than
turn
 > on. I hope I'm almost there, but lately it has been a case of two steps
 > forward two steps back. There are wounded parts all over the table, but
the
 > IGBT body count is still 0 :-)
 >
 > For most sstcs and vaccuum tube coils, you want higher peak power/average
 > power. With spark gap coils, the pk/avg is so high that it doesn't matter.
 > If it did, we would run coils in the megahertz range. I think I remember
 > Ken Herrick talking about the topvolts on his coil rising linearly then
 > dropping quickly at breakout to a near constant value for the rest of the
 > burst (the cw wave region). I think that the peak/average ratio is
 > important until you reach the point where most of the energy of the burst
 > is stored in the topload, as opposed to just pumping through it. I hope to
 > be operating in that sudden release area, so it will act like a normal
 > tesla coil.
 >
 > Another reason I think of the drsstc as closer to oltc and spark gap coils
 > than to staccato SSTCs and VTTCs is that each bang is a fixed length,
 > determined by coupling and fres, so running it cw would be like  firing
the
 > gap right after quenching. if I drove the gates continuously, it would be
 > operating in a different mode, and would indeed vaporize (or at least
 > everything surrounding my precious IGBTs would)
 >
 >   Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "Stephen Conner by way of Terry Fritz "
 >
 > At 20:42 15/03/03 -0700, you wrote:
 >  >Original poster: "Jim Lux by way of Terry Fritz "
 >  >
 >  >
 >  >
 >  >
 >  >Herein lies the fundamental difference between CW (tube and SSTC) coils
and
 >  >disruptive coils. A huge tube coil (even a 100 kW one) doesn't have the
 >  >peak powers that a disruptive coil does. And that's why the spark
 >  >characteristics are so different. The power levels when the spark is
 >  >growing are radically different.
 >  >
 >  >
 >  >By lowering the fres to something lower, you can get the peak currents
down
 >  >(L gets big) for the same bang energy, but that effectively increases
the
 >  >time over which the energy is transferred, reducing peak power to
something
 > &gt!
 > ;reasonable.. Go far enough, and the peak to average ratio starts to get
 >  >close to 1 and you have a CW coil.
 >  >
 >  >Staccato operation of a tube coil is sort of in between..
 >
 > I think this is pretty interesting, I can see the disruptive and CW camps
 > kind of converging nowadays. If Jimmy Hynes ever gets his DRSSTC to work
 > then the confusion will be complete. As far as I understand it, the DRSSTC
 > is a kind of ultra-staccato SSTC with a resonant primary that builds up
 > hundreds of amps. It operates in short bursts of ~100uS and if you ever
 > tried to run it CW it would vaporise.
 >
 > Steve C.
 >
 >
 >
 >
 >
 > Jimmy
 >
 >
 >
 >