Streamers

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

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>


> > Ok....by definition a Tesla Coil is an air-cored radio frequency
>>RESONANT TRANSFORMER...right? good

> > Now, Resonant and Transformer both seem to indicate an AC thing to me, I
> > have yet to see a DC Transformer (though I could REALLY use a few), or
> > anything that resonates only one way never crossing a zero point.

> > Ok....then, what's the toplaod do?

> > A Topload forms one side of a large air capacitor, cool, now, when the
> > capacitor discharges (i.e. a streamer) it does this either into the air, or
> > into a grounded object, the instantanious discharge would be DC because
> > we're dischargeing a capacitor.
 
> It is important to be really clear about what happens and when. We
> are dealing with several elements where vastly different timescales
> are involved. In a typical disruptive TC with typically loose
> coupling, voltage across the length of the secondary oscillates with
> increasing amplitude at the system resonant frequency until the
> primary cap is empty.

	I suggest the term 'empty' is a tad ambiguous.
	(tho this IS a fine point...)

	The cap may be said to 'empty' at each half cycle,
	of which several take place for each charging pulse
	(I'm talking AC or DC driven spark excitation, rather than CW.)
	I would define the end of the 'ring down' (primary side) as where
	the cap/primary _system_ is _nearly_ empty OF ENERGY.

>The accumulation of energy is a dynamic process. The terminal doesn't
> just gradually increase in voltage with a single polarity. Think of a
> swing swinging higher and higher as the person pushing the swing pushes
> with less and less oomph each time the swing reaches them until finally
> they push no more.

	concur....

> > But it's an AC system!???
 
> But streamer formation takes place in *far* less time than the time
> per cycle of oscillation.

	Errrrr.
	Perhaps.
	However the VISUAL EFFECT is due to multiple discharges, too
	fast for the eye to follow. down a common spark channel.

	(devilishly difficult to instrument, as the channel
	has remnant glow...)
 
> > Ok, now if the topload stores energy until it overcomes the breakdown
of the
> > air and the maximum charge density allowed for the given curvature of the
> > toroid the it has to be storing that energy during several cycles of the
> > ringdown.
 
> Ringdown => that the terminal voltage is still oscillating, changing
> polarity, in accord with system Fr. Energy content remaining is
> reflected in the voltage the terminal reaches on each peak of a half
> cycle of oscillation.
 
	Concur with remainder...

	best
	dwp