Re: SSTC not working as expected

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

Original poster: "rob by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rob-at-pythonemproject-dot-com>

Tesla list wrote:
> 
> Original poster: "Alan Sharp by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<AlanSharp-at-compuserve-dot-com>
> 
> Rob,
> 
> Your topload maybe too big - have you got a breakout point?
> 
> Another possibility (though unlikely from your description) is that
> you are at a harmonic frequency - not the fundemental.
> 
> how do you stop the flyback transformer from saturating with DC?
> 
> Is that snubber big enough?
> 
> Alan Sharp
> 

Hi Alan! Great to see you on the list.  I fixed my problem, it was too
low gate drive.  What threw me off was that there was still alot of RF
coming out of  the transformer.   I am definitely at the fundamental,
got lots of streamers before the FETS and/or IGBT's blew up.  But the
new IR "Warp Speed" IGBT's do switch at 250khz, and last longer than the
FETS, probably due to lower dv/dt.  I am impressed.

The purpose of this coil and setup is to try unusual driver
configurations.  I'm pretty bored with the usual stuff.  Yes I do need
to revisit the snubber.  And I will rewind my ferrite transformer today,
and also try a gapped one.

I have been thinking alot about the traditional interupter.  An
excellent question is:  Why do you just get a small flame or streamers
CW, but giant discharges when using an interupter?  I believe its the
flyback principal.  With the interupter you give the coil a chance to
build up a hefty magnetic field, and then suddenly shut it off.  Perhaps
the result is a big discharge from the collapsing fields.  Or another
possibility is that when power is on, the driver is too closely coupled
to the coil, so when the interupter acts, the coil freewheels its stored
energy.  Just theories.  But probably could be proven/disproven in a
faraday cage with a dual channel scope.

Sincerely,  Rob.

-- 
-----------------------------
The Numeric Python EM Project

www.pythonemproject-dot-com