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Re: Secondary Coil Electrostatic Charge

tesla-at-grendel.objinc-dot-com On Wed, 20 Mar 1996 13:31:05 +0700, you
wrote:

>>From rwstephens-at-host.ptbo.igs-dot-net Wed Mar 20 01:18 MST 1996
[snip] I said,
>Robert,
>	Given a damped wave form: at some point, the damped waveform
>is to weak to cause a discharge. That leaves the previous half cycle's
>charge on the object.
>
>	jim
>
>>>Jim Fosse,
>
Robert replied,
>>>You're almost there, but it has nothing to do with an actual 
>>>discharge (corona).   That first 180 degrees of the big whallop that 
>>>comes off the top of the TC (corona or not) goes either positive or 
>>>negative depending on when you look at it in reference to the 
>>>charging polarity of the system capacitance.  Let's say it goes 
>>>positive +100%.  During the second 180 degrees of the first RF cycle 
>>>it will swing negative,  but since we're dealing with a 'damped 
>>>sinusoid' it has already diminished in amplitude, so it goes negative 
>>>say only -70%, it then goes positive again maybe to + 40% and then 
>>>negative to -20% and then quickly dies out.  That big initial whallop 
>>>of +100% followed by an opposite or partially cancelling -70% high 
>>>voltage waveform leaves a residual DC charge on dielectrics in its 
>>>immediate area.  If that 100% represents 1 megavolt (easily achieved 
>>>with a modest 15KV 120MA neon powered system), then that +30%
>>> residual is 300,000 volts DC!  At these kind of voltages even the
>>> microscopic capacitance represented by a small section of plastic dielectric
>>> on the outside of the secondary winding  can store enough charge to give 
>>>a person a nasty shock!
>>>Note that a vacuum tube powered Tesla coil which operates in CW,
>>>generates a continuous wave train of equal amplitude, SYMMETRICAL RF
>>> sinusoids and that this type of TC does not demonstrate this residual DC
>>> static charging effect, on its own secondary or on nearby surfaces.
>
>>>Happy coiling, R.W.S.
>
>
	DING (light going on). I totally missed thinking about
charging a dielectric in an E field and was totally focused on some
other physical process causing it!

	On second thought, I've only observed it with the occurrence
of corona, so it may also be caused by contact charging from (air)
ions. Or it may be because the spark lowers the Q so much that there
is a much larger damping factor. I say this because I have not felt
the charge when my system had the toroid on and the measured E field
is 80% larger than when the hemisphere is attached.

Thanks for the food-for-thought. I've not had such an AH-HA reaction
in years!

	jim