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Re: secondary design?? RE: distributed capacitance measurement? Isotropic?




From: 	William Noble[SMTP:William_B_Noble-at-classic.msn-dot-com]
Sent: 	Sunday, September 07, 1997 7:44 AM
To: 	Tesla List
Subject: 	secondary design?? RE: distributed capacitance measurement? Isotropic?

the post below got me thinking - I know this is a dangerous thing, but sitting 
here 15,000 miles from home, I can't go run an experiment.  Anyway, if it is a 
good thing to have short secondaries (so more of the coil is in the field of 
the primary), and if it is a good thing to minimize surface area, why not a pi 
wound secondary - if a thick walled tube were used instead of thin, then it 
could be groved - for example a grove of .1 inch wide and .25 inches deep (in 
1/2 inch thick tubing) could be made every 1/4 inch.  these groves would then 
be filled with wire - with 24 gague or so, there would only be one or two 
turns per layer, so maybe 25 to 50 turns per grove (not too much voltage build 
up).  Once wound, the coil could be suitably coated to elimiate surface 
conduction effects (ie no air exposure of the wire).

Any thoughts??? - this is like the idea someone else posted of threading the 
secondary form, but you would get a higher number of turns per inch

-----Original Message-----
From:	Tesla List 
Sent:	Saturday, September 06, 1997 4:23 PM
To:	'Tesla List'
Subject:	Re: distributed capacitance measurement? Isotropic?
[bill]  snip 
Malcolm, I know you have done a fair amount of work with tight-wound
and also with space-wound coils. Have you noticed anything odd about
the total distributed capacitance of space-wound versus tight-wound
Tesla secondaries? Is there any correlation between distributed
capacitance and exposed wire surface? Or is it primarily an
inter-turn phenomenon? What does that have to say about the relative
merits of tight versus space windings? My own work has led me to
believe that the exposed surface area of a coil is very important,
especially in regard to the electrostatic phenomena that accompany
Tesla coil operation. Probably much greater in its overall EFFECTS
than the inter-turn capacitance. By the same token, the proximity of
the inside of the coil windings and the coil FORM result in
interactions that greatly affect the Q of a coil. The losses are
probably capacitive in nature, in that energy is capacitively coupled
to the material that makes up the form.

For what it's worth...
Fr. Tom McGahee



[bill]  snip