Re: Pushing the IGBT Envelop

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

Original poster: "Greg Leyh" <lod-at-pacbell-dot-net> 

Hi Antonio,

Nice program!  I'll have to work with it some more to understand it more 
fully, though.
For some reason it took my inputted values and changed them?  I probably 
entered them
in the wrong spot.
Have you studied primary drive scenarios that attempt to recover the unused 
energy from
the secondary?  I think this feature will be essential for the ALF.  I'm 
presently designing
an energy recovery scheme into the 1:12 scale ALF prototype, and hope to 
test it soon.


>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