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Re: Top Toroid
> Date: Fri, 31 Jan 1997 23:16:03 -0700
> From: Tesla List <tesla-at-poodle.pupman-dot-com>
> To: Tesla-list-subscribers-at-poodle.pupman-dot-com
> Subject: Re: Top Toroid
> Reply-to: tesla-at-pupman-dot-com
> Subscriber: jim.fosse-at-bdt-dot-com Fri Jan 31 23:11:00 1997
> Date: Sat, 01 Feb 1997 03:21:50 GMT
> From: Jim Fosse <jim.fosse-at-bdt-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Top Toroid
>
>
>
> >Subscriber: rhull-at-richmond.infi-dot-net Thu Jan 30 22:56:39 1997
> >Date: Thu, 30 Jan 1997 18:27:28 -0500 (EST)
> >From: richard hull <rhull-at-richmond.infi-dot-net>
> >To: tesla-at-pupman-dot-com
> >Subject: Re: Top Toroid
> >
>
> >I trust these are calculated values!!! I can almost tell due to the fact
> >they are all in error from real world, honest to God, measured values. A
> >true, relative isolated toroid is usually about 25-30% lower in capacity
> >than the calcs say it is. My 12X3 spun unit is 7.8pf and my 5X20 is 15.1
> >pf. put them on a coil and they can appear to be even more than calculated!
> >It's a crap shoot! The thrust is that the math isn't even close for any
> >form of critical engineering purposes. Especially on small toroids.
> >
> All,
> Does any one have voltage holdoff vs radius of curvature
> values or formulas for toroids? Or suggestions for ROC vs power level?
>
> I'm asking because I've bought my TC back on line and I only getting
> 2' air discharges from the toroid. WHAT you say! Only 2' discharges?
> Yes but, there are about a dozen at once. I'm using a 15kV 60ma
> transformer, 16nF primary cap, 120uH inverted cone primary, 8" by 20"
> #22 secondary and a 27" by 3" toroid. The resonant frequency
> (instrument measurement) is 133kHz.
>
> Any suggestions for a toroid major and minor diameters for this?
>
> Regards,
>
> jim
Jim,
Congratulations for getting sparks out of the top this time. ; )
I think the many simultaneous streamers is an indication that your ROC
is too small. Good question. I myself would like to see a good
reference to actual breakaway voltage versus ROC but since nobody can
actually put a hard number on the length of a streamer in air versus voltage
then I don't think this is really possible. Too many variables are
involved. I think there is another mechanism at work here as well.
I've seen the effect you describe on coils when they first start up,
but then as one dials in more power, one of those streamers will
mature and hog all the power, eliminating all the other little
imature starter streamers. Could be you just don't have enough power
for your toroid.
rwstephens