Re: Sheppard-Taylor SSTC driver

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

Original poster: "Jan Wagner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jwagner-at-cc.hut.fi>


> I was wondering if anyone else has ever tried this type of driver for
> SSTC use.  I am trying here.  The Sheppard Taylor circuit is unique in
> that is doesn't require any charge reservoir on the DC supply.

As in the following?
 http://www.eie.polyu.edu.hk/~cktse/pdf-paper/PE-9809.pdf
 http://www.en.polyu.edu.hk/~cktse/pdf-paper/PE-0001.pdf

A rather odd form of a boost converter, but it looks very interesting
as a single-switch converter or PFC pre-reg...  :o) 
PFC would be simple with that one. 

The continuous mode buck converter following that PFC section probably is
the TC pri itself?  I.e. where did you hook up your TC primary coil? (or
base drive xfmr?)

Figure 2 doesn't seem applicable for TC sec drive, as the output section 
is in discontinuos mode...? Also, the TC sec will be driven only for half,
or shorter, of one cycle of f_res. Or am I missing something there?


> That is how my spice simulaton looks.  However, in real life I keep
> blowing out just one of the FETS.  I think I need to make a new board
> with much better grounding :)    Rob.

Quite likely. :) Both switches should see the same stress so if just one
fails always then you've an layout issue there. The switches aren't
soft-switched but switched under rising current and voltage so the
turn-off might cause some nasty ringing and stuff. 
Well, at least if I interpreted the schematic and figure 13 correctly,
anyway... ;)

good luck!

cheers,
 
 - Jan

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