Re: Toroid Modeling One Last Time

["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 Ralph,
Comments intersperced;

Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Parpp807-at-aol-dot-com>
>
> Hi Bart,
> Sorry it has taken me so long to respond.
> Your note was very helpful. I had the impression that your graph was
> derived with an infinite number of points via ETesla6.

Not an infinate number of points. Data corresponding to 1" increases to toroid
diameter.

> Now I understand that you have plotted these points. So I am curious
> now as to what instruments you used to take the measurements.

These are not measurements. This data directly from E-Tesla6.
I run the program for each toroid size leaving everything else unchanged
for the
range of data to be captured. The frequency of which the program derives is
logged
in a spreadsheet. From the frequency, the top capacitance for each size is
calculated. Also, for each toroid size, the isolated capacitance is calc'd. The
graph's simply show this data over the range of toroid diameters. Previously, I
showed the difference as a percent to the isolated capacitance of the
toroid, but
now I'm just showing capacitance.

> Looking at the two graphs you put on your web page earlier today
> left me a little confused for a change.  :-))
> How can the "isolated" capacitance and the "effective" capacitance
> both be zero at the same time?

If it's the latest 2 graphs showing capacitance, then you have me confused.
Neither
graph shows isolated or effective capacitance at zero. For the 1" minor
diameter
graph, the isolated plot is 3pF and the effective is 1pF. The 3" minor diameter
graph starts at 10pF for the isolated plot and 6pF for the effective plot of
capacitances. Both graphs increase in capacitance as the diameters are
increased.
The lines do cross one another when the isolated and effective capacitances are
equal, but then the effective capacitance continues rather linearly. Note
that on
the 1" minor diameter graph, the last few data points are more than double the
capacitance for an isolated capacitance calculation. This would have
corresponded to
the older percent reduction graphs over -100.

> Also, it would make the graph more readable if you would plot (show) the
> actual points
> on the graph and then draw the straight or curved line that best approximates
> the point
> distribution.

Because of the number of data points, I chose to turn off the dots along
the line.
The graphs were really messy. I plan on simply continuing collecting data
and not
putting more time into graphs at the moment. Really, the only reason I
originally
graphed the data at this time was the strange look to the graph where it
showed the
capacitance decreasing beyond the crossing point. But Paul alerted me that
something
must have been wrong and he was right. The capacitance should have
increased. The
error was me keeping the percent columns in the spreadsheet positive. I
should have
just left them alone. Once I corrected the error, the graph did represent an
increased capacitance.


> Thanks again for the interesting discussion. It looks like a lot of work.
>
> Ralph Zekelman

Yep, it is a lot of work because it's one set of parameters at a time and
there is
almost an infinate number of possibilites. Can't get them all, but it would
be nice
to get some of the common parameters logged and at the least, compare small and
large coils for the effects on the change in frequency's, capacitances,
wall and
ceiling distances, coil ratios, inductances, etc.. and compare results
between a few
coils. If there's enough data, maybe one of the great mathemeticians on the
list
will be able to come up with some hard formula's to better approximate the
effects
of the basic structures internal and external to our rather sensitive coils.

Take care,
Bart