RE: Simulating Load for SSTC Coil Simulations - Terry Fritz model?

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

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>

Hi John,

I should point out that the signal in this case is from a continuous wave 
sine power source with high spectral purity.  I think the harmonics are at 
least 50dB below the fundamental.  The generator has load matching 
transformers to help match the resistive impedance of the load and the 
Tesla coil itself is tuned will to match that.  Also, the generators 
frequency can be adjusted at will until the VSWR = 1.  I should point out 
that the power levels are filtered a bit to give "nice" numbers into plasma 
loads, but it is pretty good.  All the generator is looking for is for the 
voltage and current to the load to be exactly in phase which is pretty easy 
with frequency control.

Cheers,

         Terry

At 02:35 PM 1/31/2004, you wrote:

>Terry -
>
>Your measurements of the impedance of the brush discharge of a TC is opening
>up a whole new territory of TC research. I believe this research was first
>started by the Corums several years ago and was briefly covered in some of
>their writings. You said you were able to tune the coil with ZERO watts
>reflected. This would refer to the VSWR of the coil. The VSWR graph for
>radios and Tesla coils is shown in the Tesla Coil Notebook. The VSWR for
>radios differs from Tesla coils because radios feed a resistive antenna load
>and Tesla coils feed secondary terminals which are a capacitive load. The
>basic equation is
>
>     VSWR = (Vf+Vr)/(Vf-Vr)
>
>This is related to the Q factor by
>
>      Q = (pi/4)x VSWR   Q = pi/Log dec
>
>The Q factor for 10% ringdown is
>
>      Log dec = ln(a1/a2) = ln(10) = 2.3026
>      Q = (pi)/(log dec) = 3.14159/2.3026 = 1.3644 per cycle
>
>To my knowledge there has been little TC work done in this direction so it
>will be interesting to see how the tests compare with the graph. Are there
>any other coilers that have looked into this TC subject?
>
>John Couture
>
>--------------------------------
>
>
>-----Original Message-----
>From: Tesla list [mailto:tesla-at-pupman-dot-com]
>Sent: Thursday, January 29, 2004 11:41 PM
>To: tesla-at-pupman-dot-com
>Subject: Re: Simulating Load for SSTC Coil Simulations - Terry Fritz
>model?
>
>
>Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>
>
>Hi Dan,
>
>If it is a MicroSim model, I could look at it here and see if I can find
>anything wrong.  This might be of some help too:
>
>http://hot-streamer-dot-com/TeslaCoils/MyCoils/CWCoil/CWImpedance.txt
>
>Cheers,
>
>          Terry
>
>At 08:46 AM 1/28/2004, you wrote:
>
> >Steve Ward and myself have been working with a PSPICE SSTC simulation.
> >I currently been basing my resonator model off
> >the model Terry Fritz has developed and I have used real-world numbers
> >both measured and calculated for my particular
> >resonator.
> >
> >However, during simulation, I don't believe the model is providing
> >enough of a load.  I'm getting peak currents of over 100A during max. RF
> >envelope and RMS currents of 40A+ (about 9kW+) over many periods of
> >operation.
> >
> >Do you think the discrepancy could be due to the fact of using an ideal
> >model for the input 240VAC power source or is it
> >a limitation of the model itself.
> >
> >I want to simulate the death out of this new inverter circuit, but
> >without a valid resonator model, i'm basically SOL.
> >
> >Any thoughts???
> >
> >Dan