Re: Math Doodling II

Dave, All,

Making a low voltage high current coil is difficult but not impossible.  My 
8X6 runs off of a 4000 V air-cooled CO2 laser power supply transformer.  The 
primary tank capacitors are 6- 1uf GE transmission line caps in series.  The 
biggest problem was the RSG.  I did have to put bearings on each side of the 
shaft and use a flex coupling to the motor to get a tight tolerance in the 
gaps (0.02in) so it will fire at the low voltages. It has served me well for 
about a year now, and I can say I've had a {heck} of alot less problems with 
it than I had with NSTs. 

By the way, WinTesla version 3 should be ready in a week or two.  I've added 
a metric conversion toolbar button, and I'm finishing the PSpice file output 
section.  It will have a simple RLC model, Malcoms distributed ladder model, 
and a complex model from Terry and others. It will be available for download 
at http://members.aol-dot-com/rscopper/index.htm  In the next version I'll add 
some of the power formulas that have been passed around lately.


R. Scott Coppersmith 

P.S. The company I work for (BOSCH) has published an article on my coil 
building.  If I can get permission from the lawyers to post it on my web site 
I will.

In a message dated 6/17/99 4:41:27 PM Central Daylight Time, tesla-at-pupman-dot-com 

<< Original Poster: David Sharpe <sccr4us-at-erols-dot-com> 
 I'm sorry I've not responded to the list earlier, due to family
 and work commitments.
 I'm very impressed by the thoughtful musing of the List concerning
 this topic.  It appears to be timely that John Freau's on going
 experiments involving varying sync break rates, capacitor sizing,
 and input voltages as related to the earlier post.  I suspect the
 final outcome of these equations are that high power machines
 require high voltages, and that it is very difficult (design wise)
 to build a high power machine that operates at exceptionally low
 voltages.  Trying to build a 10kW machine that would operate off
 of 2.5-4 kV would present diametrically opposed but similar
 design difficulties as building a multi-megawatt super power machine
 at inputs of 100-200kV.  Dealing with extremely high tank currents,
 large resonant capacitors (and large ESR/dielectric losses), and
 attendent circuit losses of the former; versus corona, leakage
 currents, substantial RSG design issues and high energy intercoil
 (primary / secondary or driver if magnifier configuration) flashover
 problems with the later.  I am not discounting the fact that as
 power levels scale up, the level of design and "upfront" engineering
 efforts often increase by a power function, without consideration of
 infrastructure physical requirements or costs.
 Also, as pointed out by Reinhard, maximizing Vo MAY NOT provide the
 longest spark (Thank you for the reality check  :^) ).  Something
 for our group to remember, don't let your emotions or opinions get
 in the way of good science.  As Ben Franklin admonished:
 Another gap design metric to consider is material ablation as compared
 to transfered charge through the gap system (milligrams of electrode
 material / Coulomb of transfered charge).  The lower this number,
 the less removed/vaporized material and perhaps an indication of
 gap commutation efficiency. Coulombs per bang is relatively easy
 to calculate (Q=CV); Total transfered charge about as difficult
 (Qt = CV*BPS*Total Run Time), and weighing the electrode assemblies are
 not particularly troublesome either.
 I appreciate the feedback from the collective group! And yes we'll
 keep doodling (and building)  :^)
 Chesterfield, VA. USA