RE:True Toroid Capacitance

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

Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>

Hi John,

At 09:54 AM 11/5/2003, you wrote:


>.........
>
>A check with E-Tesla6 and using the same inputs gave 25.59 pf capacitance
>and 229.58 KHz resonant frequency. The 8.16 is the secondary coil self
>capacitance. The toroid cap reduction would be
>
>     Sec term = 25.59 - 8.16 = 17.43 pf
>
>     1- (17.43/21.2) = .1778 = 17.78% reduction
>
>However, this was at 229.58 KHz and not at the measured frequency of 238.25
>KHz. I do not know why E-Tesla6 shows a different resonant frequency with
>the same toroid and Sec inductance of 18.78 mh because the surrounding
>conditions are the same.
>
>This new TC research needs to be verified with additional testing and all
>comments are welcomed.
>
>John Couture

E-Tesla6 is a +-5% program.  There are some differences in assumptions and 
calculations internal to the program.  Now days, I would expect JAVATC10 to 
be more accurate indeed!  Also note that E-Tesla6 will not compute the case 
of an isolated toroid since it will assume there is a wire going from 
ground to the toroid which will add significant capacitance from the 
connecting wire.  E-Tesla6 uses common Wheeler methods for calculating 
inductance plus correction factors from Paul's work.  Perhaps those methods 
are growing out of date now.

If one were to compare each bit of the programs the differences could be 
found.  It might just need a higher accuracy for the grid size or 
something.  But if we are getting down to needing less than 5% accuracy now 
days(!!) use Bart's program ;-)

Cheers,

         Terry