Re: PlasmaSonic II SSTC Board SALE $25.00 EACH or $45.00 for TWO

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

Original poster: "Jim Mitchell" <electrontube-at-sbcglobal-dot-net> 

But why make things so complex?  You would be wasting a whole good
oscillator and gate driver section of the plasma sonic board.  The 74HC14
used as a comparator is more susceptible to problems then using a proper
comparator (MAX913) and driving the input of the 74HC14 with that.  I saw
something on Richie Burnett's website where he uses some circuit that allows
a TL494 to sense some feedback from the coil,  perhaps you could further
evolve that.

Regards - Jim Mitchell
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, March 26, 2004 9:46 PM
Subject: Re: PlasmaSonic II SSTC Board SALE $25.00 EACH or $45.00 for TWO


 > Original poster: "Eastern Voltage Research Corporation"
<dhmccauley-at-easternvoltageresearch-dot-com>
 >
 > That is incorrect on both accounts.
 >
 > Firstly, adding a self-resonant oscillator to this board is very simple.
 > The self-resonant feedback circuit can easily fit on a small
 > 1" x 1" prototype board (which can be purchased from radio shack or other
 > sources), and fits nicely right above the existing oscillator
 > section of the board.
 >
 > I recently used the following self-resonant circuit (minus the interruptor
 > portion) with much success on one of my PlasmaSonic SSTC coils.
 > http://hot-streamer-dot-com/srward16/MiniSSTC/miniSSTCsch.JPG
 >
 > I put the two ICs (555 and a CMOS version of the 74HC14) on the small 1" x
 > 1" prototype board with the other small components and powered it from the
 > onboard
 > +12V.  The output was fed directly to the MOSFET drivers on the board.
Very
 > simple!
 >
 > Secondly, I'm not sure where you got the $80.00 from, but that figure is
 > clearly incorrect.  You can purchase IXFN44N50 MOSFETs from
 > Future Active Electronics for $18.50 each.  Its not much more expensive
than
 > something like the IRF460 and the IXFN type MOSFETS
 > are isolated allowing easy attachment to a heatsink, are bolt-mounted
 > allowing easy connection of high current connections, and can take a
 > serious beating.
 >
 > Or have the best of both worlds.  Just buy Jim's self-resonant driver and
 > the PlasmaSonic coil.  The top half of the Plasmasonic board is a
completely
 > INDEPENDENT well designed full-bridge circuit.  Just connect the
 > self-resonant driver to this full-bridge circuit and your in business.
 >
 > Dan
 >
 >
 >
 >
 >  > But that requires building a whole separate feedback system which is a
lot
 >  > of work,  It would be easier just to use the onboard Tl494 oscillator.
 > Not
 >  > the mention that the MOSFETs your design uses cost about 80$ each!
 >  >
 >  > Regards - Jim Mitchell
 >
 >