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> 

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
 >  >
 >  >
 >  >
 >  >
 >  >
 >
 >
 >