Re: Flat Coils

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

Original poster: "John Tomacic by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla_ownz_u-at-hotmail-dot-com>

All these postings about flat secondary coils made me take a quick look at 
the inductance of a flat coil and compare it to a helical coil I already 
have.  Surprisingly, the inductance of the flat spiral coil is 60% higher 
for the same length of wire. In this case the length of wire is 1478 feet.  
Since the wire resistance is the same for both coils, is it safe to conclude 
that the Q of the spiral would be 60% higher seeing that Q is proportional 
to XL/R?
If so, then there is an advantage to using flat spirals as secondaries, 
especially in magnifiers where it would be easy to feed the secondary from 
the centre, and have a toroid around the outside circumference of the 
secondary.

Also, I have an idea for winding the flat spiral, however, I still need to 
try it out to see if it works: Place 2 round plexiglass discs close 
together, separated in the center by a round spacer with spacer thickness 
equal to wire diameter and spacer diameter equal to desired inner diameter 
of coil.  Wire would then be wound around the center spacer by spinning the 
whole "sandwich", and the plexi disks would keep the wire flat as the spiral 
is built up.  One of the plexi disks could have 1/2 inch wide radial slots 
in it to apply glue to hold the wire in place after the disc is removed (or 
both disks could stay in place after finished). The spacer in the middle 
could be a pvc pipe of desired diamenter and the plexi disks would have a 
hole of the same dia as the pipe so that the discs could slide over the pipe 
to the desired separation.

John



>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Flat Coils
>Date: Thu, 14 Feb 2002 19:15:32 -0700
>
>Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><davep-at-quik-dot-com>
>
>
> > > BTW -  One can ground the center and use the outer windings as the 
>high
> > > voltage ends...
>
> >         Or vice versa, as in many of the Tesla patents.  He clearly was
> > intrigued by them, but don't remember seeing any pictures of apparatus
> > he built using them.  Has anyone?
>
>	pix in the Colorado Springs notes and 'Experiments with
>	Alternate currents of High Potential...' (or whatever
>	the exact title,  Not clear which were Secondaries,
>	which probe/test coils, perhaps.
>
>	One interpretation of the Colorado Springs notes argues
>	that the 'primary' in some/many pix is a single turn
>	(thus flat) down near the floor....
>
>	best
>	dwp
>
>
>


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