RE: [TCML] new toroid capacitance

["Christoph Bohr" <cb@xxxxxxxxxxxxxxx>]

The "Inca" Software can calculate the free air capacitance of several
shapes to a very good degree.
The fact, that your smaller diameter of curvature is not a perfect
circle may be approximated by choosing some ballpark figure between
the two values.
However, this will be a question of a few pF and not of an order of
magnitude.
Another way would be measuring the capacitance by using a signal
generator and some inductance, e.g your secondary coil ( in free air ).
Measure both the Fres with and without the toroid and you can easily
solve for the capacitance of the topload.
Good luck with whatever you are giong to try ;-)

best regards
Christop Bohr


> Good try, but as stated, this toroid is slightly odd shaped, (as per the
> linked diagram), and the spreadsheet you refer to only has
> the calculation for a standard toroid shape.  Thanks for trying, though,
> Bob.
> ---
> Reverend Fuzzy
> Pastor, MSB Ministries
> Hattiesburg, MS
>
>> -----Original Message-----
>> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
>> Behalf Of Bob Wroblewski
>> Sent: March 16, 2011 8:39 PM
>> To: Tesla Coil Mailing List
>> Subject: Re: [TCML] new toroid capacitance
>>
>> Hi Rev Fuzzy,
>>
>> Do a web search for QTC.xls then you can save it and use it locally.
>> It is a spreadsheet program from Ed Sonderman modified by Ross
>> Overstreet. I've
>> used it quite often over the years. It has a toroid capacitance
>> estimator based
>> on two dimensions of the toroid. My two cents worth. Good luck.
>>
>> Bob Wroblewski
>> Dracut, MA
>> ________________________________
>> From: Reverend Fuzzy <cmayeux@xxxxxxxxxxxxxxxxx>
>> To: Pupman Tesla List (Pupman Tesla List) <tesla@xxxxxxxxxx>
>> Sent: Tue, March 15, 2011 2:00:47 PM
>> Subject: [TCML] new toroid capacitance
>>
>> I hope someone knows this one... I've made plans for a new toroid, but
>> the shape
>> is slightly odd, compared to what we've been using.
>> I acquired a pair of 2"x11.75" Styrofoam rings (each with one side flat,
>> the
>> other side rounded).  My idea is to mount these in a
>> 11.75" round section of 3/16" plywood.  Question is, what would be the
>> resulting
>> capacitance of this topload?  I'm hoping for
>> something in the range of 16pf to 26pf, but not holding my breath on
>> that.
>>
>> See PDF diagram: http://www.msbministries.org/new_topload.pdf
>>
>> Thanks in advance for the help.
>
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>
>


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