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,

On 14 Aug 2002, at 23:42, Tesla list wrote:

> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi Malcolm,
> 
> At 04:01 PM 8/15/2002 +1200, you wrote:
> >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
> >
> 
> We have a cap, IGBT array, and a primary coil.
> 
> The cap specs are, for ten in Parallel (done well), 0.4 mOhms (0.0004)
> 3.8nH.  The IGBTs have an effective resistance of about 0.001 ohms!!
> 
> The primary coil is 14 inches in diameter of three parallel 1/2 inch copper
> tubes:
> 
> http://hot-streamer-dot-com/temp/P8140005.jpg
> 
> F0 = 33kHz.
> 
> So we are dealing with "really small" impedances here :-))  It seems crazy
> passing such low (500V) through such low impedances (milliohms) to get
> oscillation, but that is what this thing is about...  We are looking at
> 3000-5000 amp peak primary currents too!
> 
> Sounds "odd", but no HV tranny and no variacs...  A very different machine
> indeed ;-))
> 
> Hehehehehe!!
> 
> Cheers,
> 
> 	Terry

It sounds pretty good on paper for sure.

Regards,
malcolm