Re: Mutual Inductance & K Factor

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi John,

Hope I didn't sound condescending or anything like that (that wasn't my
intent). I just wanted to
point out my personal observations. Regarding a standard reduction, I
thought you "were" using one in
JHCTES, which is why I threw out some of my thoughts about it's use. As you
were referring only to the
limited testing, I stand corrected. Sorry about that.

Best regards,
Bart

Tesla list wrote:

> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
>
> Bart -
>
> Wow - I didn't mean the 15 to 25% was a "standard reduction". As I said my
> tests were limited. If you found greater reductions by tests I would not be
> surprised and would accept this as valid information. I also agree that the
> ETesla6 program is the best available at present unless Malcolm knows of a
> better one.
>
> John Couture
>
> ----------------------------
>
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Thursday, March 21, 2002 7:14 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Mutual Inductance & K Factor
>
> Original poster: "Barton B. Anderson by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
>
> Hi Malcolm, John -
>
> ETesla6 is the best program to date for a pre-determined frequency with
> topload by which we can
> determine effective top C because it pulls in the walls and ceilings.
> Measurements run against ETesla6
> confirmed it's accuracy to me. My top C measurements varied a wider range
> than 15 - 25% and can easily
> be confirmed by any coiler who takes Fres measurements while changing top
> load dimentions, terminal
> heights, terminal to ground heights, etc. Modeling with ETesla6 will also
> show a large variation.
>
> If empirical data is where the 15 - 25% values were derived, then I suspect
> this data-set of coils just
> happened to fall within that range and probably from a commonality of coil,
> toroid, and terminal height
> ratios. I do agree that about 20% appears common. The only problem I have
> with a "standard reduction" is
> that the value used can be way off on many coils. If ETesla6 is used, a
> standard reduction is no longer
> needed. The real trick is to pull this function into design programs. We
> have all the parts (electrical
> and physical). It's just a matter of sitting down and getting it done.
>
> Take care,
> Bart
>
> Tesla list wrote:
>
> > Original poster: "Malcolm Watts by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
> >
> > Hi John,
> >
> > On 21 Mar 2002, at 16:38, Tesla list wrote:
> >
> > > Original poster: "John H. Couture by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> > >
> > >
> > > Bart -
> > >
> > > Thank you for the explanation regarding ETesla6. I should have realized
> that
> > > this was a possibility because ETesla6 does this so well. This goes back
> to
> > > the time I pointed out on the List that after the TC is built and
> tested the
> > > JHCTES Ver 3.3 program can be used to find the true capacitance of the
> > > toroid when placed on the secondary .
> > >
> > > When the toroid is placed on the secondary the toroid capacitance is
> reduced
> > > an indeterminate amount. Etesla6 estimates an operating frequency so the
> > > toroid capacitance can be estimated very closely before the coil is
> built.
> > > The actual value can be found with JHCTES Ver 3.3 or Java9.1 by
> reducing the
> > > toroid capacitance value until the program operating frequency agrees
> with
> > > the actual test operating frequency.
> > >
> > > The toroid capacitance reduction has been discussed in the past on the
> List.
> > > My own limited tests indicated the reduction to be about 15 to 25%.
> Because
> > > the only way to find the true toroid capacitance on the secondary is by
> > > tests all coilers will have to wait until enough tests are made. The
> > > programs can then be updated to give more accurate outputs.
> >
> > "Indeterminate amount?" I refuse to believe that a well behaved
> > result cannot come from some correct modelling and applied physics.
> > As for the 15-25% figure, that might be ballpark for a lot of systems
> > but as I have found, the actual figure can be almost 100% if the
> > terminal has a considerably smaller diameter than the coil. That is
> > not to say it is useful or practical to do this but it is an
> > illustration of the degree of variation that can be obtained.
> >
> > Regards,
> > Malcolm