Re: OLTC - Primer

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Terry,
          I'd be tempted to run a sim with a 500nH inductor and 47uF 
and see just how low total primary AC resistance has to go to score a 
Q of 10 or so (typical of a half decent SG coil) at your proposed 
operating frequency.

Regards,
malcolm

On 14 Aug 2002, at 21:11, Tesla list wrote:

> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi Ted,
> 
> You have been looking close :-))
> 
> The switch in the schematic has the primary resistance hidden in its
> definitions.  "Tonights" schematic has them more visible ;-))
> 
> http://hot-streamer-dot-com/temp/OLTC8-14-02.gif
> 
> If we have a 32kHz operating frequency with a 500nH primary, we can
> calculate the Xz impedance as only 0.1 ohm!  The primary impedance must be
> "extremely" low for the system to oscillate.  However, the IGBTs can do
> 2000 amps with 5 volts drop.  That is 0.0025 ohm (actually better (~0.001)
> in a dynamic model case).  The 10 caps in parallel are 0.0004 ohm at 3.8nH!
>  So it is up to the primary to be low loss too, and it's all done and
> working ;-)  The primary sure "looks" like an inductive dead short :-))
> 
> BTW - I have been trying to get this model so it can be downloaded, but
> some model redefinitions and such make it very hard to transport and have
> work...  Many bugs in MicroSim 9.1...  Grrrrr...
> 
> Cheers,
> 
> 	Terry
> 
> 
> At 01:42 PM 8/15/2002 +1200, you wrote:
> >Hi Terry et al
> >
> >Been looking at the computer model schematic.
> >Wondered if it needed a low value for Rp to be added ?. Perhaps it would
> >provide a sensitivity analysis of Rp to Vs.
> >Best
> >Ted L in NZ
> >
> 
> 
>