Re: SSTC idea - DRSSTC ?

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

Original poster: "jimmy hynes by way of Terry Fritz <teslalist-at-qwest-dot-net>" <chunkyboy86-at-yahoo-dot-com>


  Hi Chris,

DRSSTC stands for double resonance solid state tesla coil. It uses IGBTs in 
an h-bridge to drive a capacitor in series with the primary of the tesla 
coil. The primary and capacitor are resonant at the same frequency as the 
secondary, so the voltage across the primary rises with resonance. The 
current also rises to about 1000amps. It's just a really high peak power 
sstc. Most of the information on it is in the archives, but today I put 
some stuff online at hot-streamer-dot-com/chunkyboy86. DRSSTC.doc has some 
explanation stuff, but not too much. I am going to make a real website for 
it when I'm done with it.



   Tesla list &lt;tesla-at-pupman-dot-com&gt; wrote:
Original poster: "chris swinson by way of Terry Fritz "


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"
To:
Sent: Tuesday, March 18, 2003 12:58 AM
Subject: Re: SSTC idea


 > Original poster: "jimmy hynes by way of Terry Fritz "

 >
 >
 > 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
&gt!
; 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 whe! re 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 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
 > >!
 > ;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
 >
 >
 >
 >



Jimmy