RE: Primary/Secondary Size relationship

["Lau, Gary" <Gary.Lau-at-compaq-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

The relationship between the primary and secondary simply determines the
coupling coefficient "k" between the two.  Nothing special occurs when the
secondary passes below the plane of the primary - it's just a smooth
continuum with k increasing the closer they get.  What you propose will
certainly work, but its very possible that the optimum coupling for best
performance may be greater than what you can achieve.  Smaller coils in
particular need a higher coupling.  Try it and see.  If you find that
performance diminishes if you raise the secondary above its lowest point,
then it would probably improve if your primary allowed a lower setting.

Regards, Gary Lau
Waltham, MA USA

		-----Original Message-----
		From:	Tesla list [mailto:tesla-at-pupman-dot-com]
		Sent:	Friday, July 14, 2000 10:01 AM
		To:	tesla-at-pupman-dot-com
		Subject:	Primary/Secondary Size relationship

		Original poster: Irrelative-at-aol-dot-com 

		When creating the primary of a tesla coil, does the
secondary have to fit 
		inside the primary or can it "hover" above it.  For example,
if you have a 4" 
		PVC, but the inside diameter of your primary is 3", can you
still use them so 
		long as the secondary is high enough away to prevent sparks
from jumping?  
		Ok, so maybe this question is seeming less hypothetical as
you read it, but I 
		just want to see if I need to get a larger primary or not.
Thanks to all the 
		experts who keep us informed!