Re: Sheppard-Talyor circuit up on my website

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

Original poster: "K. C. Herrick by way of Terry Fritz <twftesla-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>

Rob (& all)-
 
I've downloaded your schematic, am studying it, & will dash off quick comments
herewith:
 
1.  I think you'd need the 3 diodes to be fast ones, to accomodate any decent
clock frequency at all: 4002s (& their ilk) are very slow at turning off.
 
2.  What's R35 for?
 
3.  You might need low-ohm (15-50) resistances in series with TX11 and TX12 to
damp them--rather than R34 and R19.  I wouldn't think you'd need the latter two
at all.
 
4.  I wonder if you could eliminate R38 and R36?  It appears that R37 finds
itself in series with first one, then the other.  Just let R37 alone do the
job.  But then...what job is that?  Parasitic suppression? 
Current-limiting?--except that a) L16 limits it during the 1st phase and b) I
shouldn't think you'd want it limited, except by TX4's impedance, during the
2nd phase.
 
5.  Is it you intention to resonate C26 and TX4?  Or just to let the Tesla coil
be the only resonant element?  Or have you gotten that far?..
 
Interesting circuit.  Have you done it yet in hardware or only in simulation? 
(I.e., "blowing things up" for real, or not?  If the former, welcome to the
club.)
 
Ken Herrick
 
 
On Fri, 28 Jun 2002 21:29:19 -0600 "Tesla list"
<<mailto:tesla-at-pupman-dot-com>tesla-at-pupman-dot-com> writes:
> Original poster: "rob by way of Terry Fritz
<<mailto:twftesla-at-qwest-dot-net>twftesla-at-qwest-dot-net>" 
> <<mailto:rob-at-pythonemproject-dot-com>rob-at-pythonemproject-dot-com>
> 
> Its under the "Coil Corner" link with the rest of the Tesla stuff.  
> Its
> such a neat idea for a converter, I think I am becoming obsessed 
> with
> getting it to work.  Here how it is supposed to work (i.e. no 
> explosions
> of MOSFets):
> 
> 1.  120*1.414 Volts charge up the 0.1uF storage cap to Vc through 
> the
> 160uH inductor and two diodes at t=0.  Then at some point, both 
> FETs
> turn on simulaneously, reverse bias the diodes, and dump -Vc through 
> the
> third diode to the output transformer.  The inductor keeps the two 
> fets
> from drawing infinite current when turned on during the short pulse. 
> 
> The cycle then repeats.
> 
> 2. I've read numerous accolades of how this circuit produces low 
> stress
> on the components, unity power factor, and low EMI.  I'd love to 
> know
> how they did it, or what I am doing wrong.
> 
> 
> -- 
> -----------------------------
> The Numeric Python EM Project
> 
> <http://www.pythonemproject-dot-com/>www.pythonemproject-dot-com
> 
> 
> 
>