Re: Fwd: Re: Calculating streamer breakout of top-loads

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 13 Sep 2003, at 10:33, Tesla list wrote:

 > Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>
 >
 > I wondered this myself,  If you have a source with say a fixed source
 > impedance and you vary the load impedance, then the maximum power transfer
 > is with the Zload = Zs.  However, if the load impedance is fixed and the
 > source impedance is varied, then the maximum power transfered is with Zs = 0
 > to get maximum voltage on the load.
 >
 > I'm wondering in this case, if the coil impedance is dependent on its
 > inductance and Fres and to get a low impedance coil means to either reduce
 > the number of turns on the secondary or to lower the resonant frequency.
 > The former may be counterproductive.  The latter could mean a larger top
 > load and too could be counterproductive beyond a point.  I believe Terry
 > modeled each streamer as a 220K resister feeding a capacitance of 1 pf per
 > foot of streamer.  He had the entire system in the model (ideal sparkgap, TC
 > primary and secondary modeled as a transformer with primary inductance,
 > secondary inductance, coupling coefficient k, top load capacitance combined
 > with the Cself of the coil and varied the output impedance to maximize the
 > power to the streamer.  See his web page for details.  He effectively
 > thevenized the coil to determine the output impedance.

Suppose the idea is a goer. The challenge is then on to build a
secondary whose output impedance remains a conjugate of 220k - jnwC
where n is expected spark distance in feet and C is the 1pF. At least
I'd consider it a challenge. Just meeting the 220k requirement would
be a nightmare. Try designing a secondary whose Zo is 220k and see.
Most if not all are well below 100k. I think the losses incurred in
meeting the specification would outweigh the benefits by a
considerable margin. The essence of such a design would be a compact
size to keep Cs down with a humungous amount of thin wire to get Ls
up. Copper losses would very quickly become a major factor in my
opinion.

     BTW, the 220k appearing to be constant regardless of sparklength
says something about the (non)linearity of the situation.

Malcolm