Re: A primary question

Subject:  Re: A primary question
  Date:   Mon, 21 Apr 1997 19:58:59 -0400 (EDT)
  From:   richard hull <rhull-at-richmond.infi-dot-net>
    To:   Tesla List <tesla-at-pupman-dot-com>

At 12:43 AM 4/21/97 -0500, you wrote:
>Subject:  A primary question
>       Date: Sun, 20 Apr 1997 20:39:41 -0700
>       From: Skip Greiner <sgreiner-at-wwnet-dot-com>
>Organization: Greiner, Ltd.
>         To: tesla list <tesla-at-pupman-dot-com>
>Hi All
>I would like to pose a question for the list. Disregarding
>primary/secondary arc-over problems...what if one were to design and
>build three different primaries as follows:
>1. a solenoidal wound coil of the approximate diameter of the secondary
>designed to a specific L. I think this coil could actually be a larger
>diameter without changing the premise.
>2. a pancake wound coil of the same L with spacing to allow the
>secondary to fit in if necessary for k adjustment.
>3. An inverted pancake coil of the same L designed using accepted
>Now, the question.....Using the same secondary and adjusting the
>coupling to be equal for each of the three different primaries, will the
>TC function any differently in each configuration?
>I will appreciate any and all comments and discussion. I believe the
>design of the primary is the single most important part of a TC and I
>believe it has largely been ignored.

I am relatively confident that for a given primary L and coupling you
see no difference in any geometric form.  The main advantages of one
the other, as you point out and cover in your first sentence, is
one of voltage arc over prevention.

Other criteria will millitate one form over the other, too.  The flat
pancake just can't work as a maggey driver primary with a normal
secondary.  (no coupling)

  The archimediam inverted conical is best for light maggey work or
large two coil systems where .2 or above coupling is demanded. 

 The cylindrical primary is better for maggey work due to its huge
posibbilities.  Unfortunately, it is the worst possible design so far as
over is concerned, and superhuman efforts are required in maggey work to
insulate it from the tremendously violent and energetic secondary rise. 

Bottom line....Coupling is coupling.  It is magnetic energy we are
trying to
trap in the secondary as long as that energy is equal, primary to
we should care less how it got there.  Too bad we can't just miracle the
lines of force in there!!

Richard Hull, TCBOR