RE: Strange shock (fwd)

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

Hold on.  The distributed capacitance of the secondary has nothing to do
with these shocks.  The shocks are from a _DC_ static charge deposited on
the surface of the secondary's polyurethane (or whatever) coating.  The DC
charge occurs due to the rectification mechanism of corona - that it occurs
more-so in one polarity than the other.  What's underneath this charged
layer of polyurethane - a coil of wire or a solid tube of copper - doesn't
matter.  The distributed capacitance of the secondary can't matter as this
capacitance only matters at high frequencies.  At DC, distributed
capacitance can hold no charge.

Gary Lau
Waltham, MA USA

		-----Original Message-----
		From:	Tesla list [mailto:tesla-at-pupman-dot-com]
		Sent:	Friday, July 14, 2000 10:48 PM
		To:	tesla-at-pupman-dot-com
		Subject:	Re: Strange shock (fwd)

		Original poster: "Daniel Boughton"
<daniel_boughton-at-yahoo-dot-com> 

		Antonio:

		While it may be true that ionized air store pockets of
		charge heavily insulated coils have significantly
		higher distributed capacitance resulting in a lower Q.
		This distributed capacitance coupled with the terminal
		capacitance is what accounts for the an inductor's
		self resonant frequency. To find the value of the
		distributed capacitance one must measure the coils
		self -resonant frequency and inductance. This can then
		be applied to the coil's series resonance formula to
		determine the coil's distributed capacitance value.
		Note this is to be done without the terminal
		capacitance. The distributed capacitance will be seen
		not to be as low as you might think. Secondarily, the
		charge in the coil is minute until the larger
		capacitance offered to the coil by touch is presented
		by the human body. The result is an in-rush of current
		to stabilize the voltage. This in-rush (reactive
		effect)is often much higher than the residual charge
		which accounts for the formation of a spark. This is
		the phenomena of a capacitor anyway. That is a
		capacitor will supply any current necessary to keep
		the voltage across its terminals at equilibrium. It
		doesn't create energy it just generates current as a
		function of time. In otherwords, I can generate 0.5
		Coulombs per second or use the same charge to generate
		0.5 Coulombs per millisecond. The rate is determined
		by the value of the capacitance while charge can
		remain constant.

		What does his coil resonate at anyway 250KHz? 100KHz?
		What's the value of his inductance? What is the value
		of the capacitance needed to cause his coil to
		resonate at that frequency with that value of
		inductance? Not so small. This is why F.E. Terman
		states mathematically that the highest Q helical
		resonantor is found when the winding length of the
		coil is equal to or less than its diameter.

		Dan