# Re: E-Tesla6, was RE: Sphere/Toroid Comparison Chart

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

Hi Peter,

At 10:44 AM 5/8/2001 -0700, you wrote:
>Terry,
>      I've been looking at E-Tesla6 and noticed that it requires as input
>the "Measured Secondary Inductance". I was sort of expecting to have to
>enter the "number of turns" somewhere, something more like ACMI which takes
>as input the dimensions of the coil and wire and then calculates inductance.
>
>If I am going to use E-Tesla6 to estimate the Fres of a coil _before_ I
>build it do I use Wheeler: "R**2 * N**2 / (9*R + 10*H)" formula for
inductance?
>How accurate is that anyway, what about Lundin's formula?

The above calculation is fine.  I just didn't want to add a bunch more
variables to be entered and figured most people would already know the
secondary inductance or could calculated is separately easily enough.

>
>I'm in the process of building 3 coils (approx 4x12, 3.5x15, 3x18) each
>hopefully with identical Fres (with the same 2x8 toroid), so I'ld like to
>use E-Tesla6 to find the exact winding length and number of turns to get
>identical Fres. Then I'll use ACMI to adjust the height of each one to get
>exactly the same K (of 1/7) for each. Then see if there is any difference
>in operation.  Not that I expect there to be any, this is just for fun,
>after all its a hobby(!).

Neat!  Be looking forward to seeing what you come up with!

Cheers,

Terry

>
>-Peter Lawrence.
>
>
>>Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>
>>
>>Hi John,
>>
>>"E-Tesla6" a program I wrote that was vastly improved by others, can find
>>the resonant frequency of a one or two torroid (or sphere) Tesla coil
>>secondary system within a percent or two.  It does all the nasty
>>electrostatic field calculations and even has elements of Paul's TSSP
>>project added.  It is freely available at:
>>
>>http://hot-streamer-dot-com/TeslaCoils/Programs/E-Tesla6.zip
>>
>>A web page with info is at:
>>
>>http://hot-streamer-dot-com/andrewb/
>>
>>It is very useful for determining the resonant frequency of a secondary
>>coil and top terminal before they are built.  Everyone seems to like it a
>>lot and it seems to work very well.  I ton of effort went into the darn
>>thing ;-))
>>
>>Cheers,
>>
>>	Terry
>>
>

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