Re: New SSTC and topology in need of review

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

Original poster: "gtyler" <gtyler-at-drummond-dot-org.za> 

Someone beat me to it! http://www.geocities-dot-com/teslinasite/oltcp
george
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, December 16, 2003 4:47 PM
Subject: Re: New SSTC and topology in need of review


 > Original poster: John Keith <jskeith-at-interaccess-dot-com>
 >
 > Hi George,
 >
 >     This circuit sounds very interesting. Would you please consider
postig
 > it, either here or to the High Voltage list?
 >
 > Thanks,
 > John K.
 >
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Monday, December 15, 2003 5:55 PM
 > Subject: Re: New SSTC and topology in need of review
 >
 >
 >  > Original poster: "gtyler" <gtyler-at-drummond-dot-org.za>
 >  >
 >  > Hi, That's basically what I am talking about: A royer cct is a
push-pull
 >  > topology with a tuned load (no mag. current) fead from a choke to
give a
 >  > constant cycle to cycle current into a centre tap.
 >  > There is a capacitor from drain to drain, i.e. across the load. In
my
 >  > induction Bearing heater the current from 220V mains is 25A rms but
the
 >  > load sees 40A at 800V or 32Kva. All this with 2 cheap IGBTs.
 >  >
 >  > George
 >  >
 >  > ----- Original Message -----
 >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  > To: <tesla-at-pupman-dot-com>
 >  > Sent: Monday, December 15, 2003 4:59 PM
 >  > Subject: Re: New SSTC and topology in need of review
 >  >
 >  >
 >  >  > Original poster: dhmccauley-at-spacecatlighting-dot-com
 >  >  >
 >  >  >
 >  >  > This is similar to the circuit I have been working on except I'm
not
 >  > using a
 >  >  > transformer to step up the voltage.
 >  >  > My current design (which is the one Steve Ward referred to)
basically
 >  > is a
 >  >  > push-pull MOSFET switch acting purely linearly (not in
saturation)
 >  >  > and designed to modulate the output of a MOT up to 500kHz or
more.
 >  >  >
 >  >  > The circuit works almost flawlessly in linear mode producing a
 >  > sinewave
 >  >  > output up to 2400VAC -at- 500kHz, but because it is linear, the
MOSFETs
 >  >  > dissipate
 >  >  > significant heat.  I'm currently trying to use the same type
circuit
 >  > to act
 >  >  > in saturation mode for a nice square wave output, but am
currently
 >  > having
 >  >  > some difficulties
 >  >  > with the gate switching.
 >  >  >
 >  >  > I'm about finished one month of my three month tesla coil hiatus
(need
 >  > a
 >  >  > scheduled break!), so probably in March i'll pick up the many
projects
 >  > I've
 >  >  > left off this year.
 >  >  >
 >  >  > Dan
 >  >  >
 >  >  >
 >  >  >  >      Interesting cct. However,would it not be simpler to use
a
 >  > lower
 >  >  >  > voltage output and a transformer to give a higher voltage if
you
 >  > need
 >  >  >  > it. This started me thinking, I have a royer type circuit
that
 >  > produces
 >  >  >  > 800V rms SINE WAVE across a load at some 25A using igbts.
(IR4GPH50
 >  >  >  > 1200v DEVICES).
 >  >  >  >
 >  >  >  > George
 >  >  >  >
 >  >  >  >
 >  >  >  >