Re: Terry's DRSSTC - Controller Experiment

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Colin,

Say were are way de-tuned.  The primary has very low loss and the current 
just keeps ringing up and up and up...  The situation is were the voltage 
getting through to the top is only say 1/4.  but if the primary voltage 
rings up to 4X, you still get the same top voltage due to the enormous 
current that is allowed to build up on the primary.  If you have say 10,000 
amps on the primary, you don't need very good tuning ;-)))

Just imagine what happens to the primary current if NO secondary is in 
place.  The current just quickly rises until something blows up!!  Since 
the DRSSTC is not power limited, if you put 1000 Watts in, the current will 
rise until 1000W + the stored energy gets out, one way or another....

Cheers,

        Terry

At 12:33 PM 4/20/2005, you wrote:
> hi terry,
>            im confused why the current would go high at either side of 
> Fres as the sum of the reactancr drops to zero at resonance right? either 
> that or you are talking about something different with Fo like oscillator 
> frequency? just asking to clear up some of the many clouds in my mind.
> cheers
> colin
>
> ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Wednesday, April 20, 2005 7:17 PM
> Subject: Re: Terry's DRSSTC - Controller Experiment
>
>
> > Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
> >
> > Hi,
> >
> > Antonio is right, as the coil is de-tuned, the top voltage tends to stay 
> > rather constant but the primary current tends to rise dramatically!!  I 
> > think Steve reported he could run with a very highly detuned coil but I 
> > suspect he was driving far higher current through is big IGBTs.
> >
> > I am tuning my DRSSTC by finding the point of least current draw.  On 
> > both sides of Fo the current goes way up.  It seems at the best tuning 
> > the current draw is the lowest.
> >
> > I am not concerned about which mode it is in since the drivers do not 
> > care and I really don't care either ;-)
> >
> > I think I can run my old Magnifier with the DRSSTC driver too.  I may 
> > have to make a new top holder since I think I "borrowed" that from the 
> > magnifier.  With the DRSSTC now, the magnifier should be far easier to study.
> >
> > Cheers,
> >
> >         Terry
.............