Flat Primary Winding - next question

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: Flat Primary Winding - next question
From: Tesla List <tesla-at-stic-dot-net>
Date: Tue, 16 Jun 1998 07:44:00 -0500
Approved: tesla-at-stic-dot-net

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From:  Larry Bud Melman [SMTP:gasman-at-althea.a-line-dot-net]
Sent:  Monday, June 15, 1998 10:35 PM
To:  Tesla List
Subject:  Re: Flat Primary Winding - next question

> This leads to another thought.  If the primary effectively couples mainly
> to the lower part of a 1000 turn secondary (e.g. the first 100 or so
> turns), then do we in effect have a 100 turn secondary feeding a 900 turn
> third coil?  In other words, does a conventional TC function as a merged
> combination of pulse transformer and magnifier extra coil?  I envision the
> transition zone from conventional two-coil TC to magnifier extra coil would
> be a gradual effect, depending on how the primary magnetic flux was shaped
> and intercepted the secondary.  I suppose the answer to this probably
> doesn't affect how to build decent coils, but perhaps it could lead to
> better understanding of how our beloved TCs actually do their thing. 
> Comments?
> 
> Lastly, wouldn't it be interesting to actually map the magnetic flux
> between primary and secondary (and floor and whatever else) to better
> visualize how concentrated or distributed the magnetic coupling actually
> is?  I have seen posts which suggest the visual purple air ionization
> visible between primary and secondary has something to do with magnetic
> coupling.  I believe the effect is purely high voltage ionization of air
> and is not an indicator of anything going on magnetically.  Comments?
> 
> Thanks in advance for responses.
> 
> --Steve
> 


	Wow.  I'm a relative newcomer here, and the amount I learn from reading
these posts is amazing.  Two weeks ago, I didn't even know what a magnifier 
*was* (not that I can exactly explain it now, except that it has a third
coil which is not magnetically coupled to either of the first two <g>), but
anyway...

	As I read this post, a potential qualitative way of getting an idea
of just how big the field from the primary is at different heights came to mind.
I wonder if it would be useful:

	Remove the secondary (as I'm sure one might not wish to get zapped with
the output from some TC's - or, at least for sure, the dreaded warthog <g>).
Then, just fire up the primary circuit and let it go.  Get a piece of paper 
covered with ferric dust, start at a height corresponding to the height of the
sec'y, and see if the dust is perturbed.  Move down slowly.....

	Of course, this might not do anything, as most coils, from what I've
read, seem to operate at frequencies in the ~50-60 to 300 kHz range, and such
high frequency oscillations may have no effect, even on ferrite *dust*, at 
least until you get into relatively higher field values.

	I guess a wire with a milliammeter on it would accomplish the same thing
more reliably...

	Cheers to all.

						Clay Wilson