Re: ETesla-6 Convergence - insignificant observation

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Matt,

>At 01:09 AM 3/18/2001 -0500, you wrote: 
>Hi Terry & All! 
>        This is something that would probably only occur to someone like me, 
>who has more computer time than a real life ;-)). I have run one of my coils 
>through the ETesla6.exe (not the c version) many times, using different grid 
>sizes. Although all the answers are close to each other, they seem to 
>converge cyclically to a logarithmic line, rather than converging to a fixed 
>value. This would indicate that generally, but not absolutely, the larger the 
>grid size, the higher the predicted frequency. I suspect it is all due to the 
>fact that any finite-precision computer doing a giga-gazillion calculations, 
>will have some bits falling into the bucket along the way. 

As the grid size is changed, the program does a little "tweeking" to
optimally fit the coil into the grid.  The scale is varied so that the coil
always falls exacly on grid points.  This improves the accuracy but does
give a little "jitter" in the answers as you vary the grid size.  As you go
to higher and higher grid sizes, the effect is less noticable.

>          Since the difference between a grid of 100 and one of 700 is only 
>1.5%, it's an interesting phenomenon, but actually it's a verification that 
>you DO have a pretty darn stable program. I would have to agree with Pogo: 
>"It don't hardly make no difference no way at all to practical folks". 

I usally like to use a grid size of at least 200 for most things.  The
latest C version (6.11c) is much faster and has some improvments so maybe
you should upgrade:

http://hot-streamer-dot-com/TeslaCoils/Programs/E-Tesla6.zip

Cheers,

	Terry 

>Grid  Final Calc. Freq. 
>100   268662 
>125   269423 
>150   269761 
>175   269761 
>200   270867 
>225   271175 
>250   270722 
>275   270794 
>300   271670 
>325   271670 
>350   272166 
>375   271733 
>400   271850 
>425   272214 
>450   272059 
>475   272155 
>500   272155 
>525   272397 
>550   272407 
>575   272725 
>600   272727 
>625   272310 
>650   272310 
>675   272511 
>700   272720 
>
>Think I'll go sleep off today's "shamrock squeezings" 
>g'night All, 
>Matt D.
>