Re: Pushing the IGBT Envelop

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

Original poster: "Antonio Carlos M. de Queiroz" <acmdq-at-uol-dot-com.br> 

Tesla list wrote:
 >
 > Original poster: "Greg Leyh" <lod-at-pacbell-dot-net>
 >
 > Interesting website, and coil work!  I'm still unclear on the DRSSTC theory
 > of operation, however.  Near as I can figure, the system actually runs as
 > an oscillator, but in a quasi-CW mode for relatively short bursts, at an
 > unspecified dwell and repetition rate.  Is this roughly correct?

My investigation, so far only theoretical, shows that a DRSSTC can be
operated almost exactly as a magnifier would (there are three
simultaneous oscillations involved), generating a voltage rise at
the output while the driver is operating and reaching an instant
where all the energy in the system is in the output capacitance.
At this point, if the driver is switched off, the energy is trapped
in the secondary system, as happens in a conventional Tesla coil
after the quenching of the primary spark gap.
The possible advantages over a capacitor-discharge system are:
- The voltage gain can be much higher.
- The primary capacitor must store only about 1/4 of the total
   "bang" energy. (Can be less, as much as you want, but with less
   than about 1/10 the required element values may be impractical)
It ispossible to continue to operate the driver after breakout,
but the input current may grow excessively.
It is also possible to operate the driver at one of the (two) resonance
frequencies of the system, but this causes a relatively slow increase
of the output voltage, with the input current increasing too.

I wrote a program that implements my ideas about how to design
these systems, and that can simulate the structures too. The "sstcd"
program is available at http://www.coe.ufrj.br/~acmq/programs

Antonio Carlos M. de Queiroz