Re: Reflections in Power Transfer

To: tesla-at-poodle.pupman-dot-com
Subject: Re: Reflections in Power Transfer
From: Tesla List <tesla-at-stic-dot-net>
Date: Sat, 17 May 1997 20:55:09 -0500
Approved: tesla-at-stic-dot-net
Subject:  Re: Reflections in Power Transfer
  Date:   Sat, 17 May 1997 19:27:17 -0500
  From:   "Robert W. Stephens" <rwstephens-at-headwaters-dot-com>
    To:   Tesla List <tesla-at-pupman-dot-com>


> Date:          Thu, 15 May 1997 09:17:15 -0500
> To:            tesla-at-poodle.pupman-dot-com
> Subject:       Re: Reflections in Power Transfer
> From:          Tesla List <tesla-at-pupman-dot-com>

> Subject:     Re: Reflections in Power Transfer
>       Date:  Wed, 14 May 1997 21:09:38 -0800
>       From:  Greg Leyh <lod-at-pacbell-dot-net>
>         To:  Tesla List <tesla-at-pupman-dot-com>
> References: 
>            1
> 
> 
> Malcolm Watts wrote:
> 
> > > True, it does change wrt time, but wouldn't the streamer start out at
> > > a high Z, with Z decreasing as power is pumped into it, until the point
> > > of maximum power xfer is reached?  Beyond that point, the spark power
> > > would start decreasing, until its Z rose back towards the point of
> > > max pwr xfer.
> > >
> > > -GL
> > 
> > I agree with what you say regarding streamer Z. But considering that
> > the current is changing continuously, so is the terminating impedance
> > and it must be changing sinusoidally I think. Is there some way then
> > we can minimize loaded VSWR and get the energy out in one cycle?
> >     I guess the point of my bit was to understand why the thing still
> > rings and I'm sure the mismatch is the element at work.
> > 
> > Any other thoughts welcomed,
> > Malcolm
> 
> 
> Do you think that the streamer impedance can change as fast as 
> the current in the sinusoidal waveform?
> 
> _GL
 
Greg,

I would hazard to guess that the streamer impedance will indeed vary and 
attempt to mimic instantaneous tracking of the 
current in a sinusoidal waveform (in phase with the voltage waveform 
of the source Tesla coil) since this factor (arc resistance in a 
gaseous medium) seems to be intimately linked to the simultaneous
discharge
path current.  

The fact that there is a dynamic growing or building upon effect in play
which 
tends to link increasing ionized pathlengths in cascade fashion with 
each preceeding Dart Leader (as also observed in the natural 
lightning case) makes this phenomenon more copmplicated to model 
surely.  I would hazard to guess that in the case of Dart Leader 
progression of the Tesla coil streamer, the impedance of the source 
(measured at the toroid) will be seen to reflect some lesser deflections
in average 
impedance, VSWR, instantaneous voltage level, and discharge current 
(instantaneous charging current supporting a capacitive growing but
unconnected 
air only streamer) in real time reflecting the activity at the leading
end of the 
travelling/exploring streamer.

There may also be a varying and complex impedance loading effect which
is
likewise modulated by instantaneous streamer length, but which is
represented 
solely by decaying ionized (low impedance paths/pockets) of air which
exist 
immediately in one direction after the active streamer has walked 
there and then decided to take an alternate route.  These decaying 
pathways ought to act as energy wells momentarily
connected to the outlying regions of the real time streamer core.  
Such energy wells may instantaneously act as storage capacitors which 
can contribute their energy to a new oncoming pulse of energy from 
the main streamer which will then have the strength to jump off in a 
new direction with added punch.

I see you and Malcolm also ponder Tesla coil event horizons on a deeper
level.

rwstephens