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Re: Formula for self C of a Coil (not Medhurst)
Hi all,
To save time I will respond to the various points in one e-mail.
Thanks Bart I have already tried that. It well behaved for low H/D unlike
the original. But it still not the true self C and when you differentiate
it it gives wrong answers unless you assume its for an isolated coil. Can
anybody confirm or deny it is for an isolated coil.
My definition of self C is the C you get when you measure it directly say
with a LC bridge or a method that is not strongly dependent on the L.
When I first discovered Medhurst self C I assumed it was the true self C of
the coil. But this leads to violations of circuit laws. So I am happy now
the circuit laws are restored and the factor has been determined for some
cases. I still need the equation for the self C of a coil though.
If you have read the other posts on measured self C (LC bridge) comparisons
to Medhurst they confirm the fiddle factor or what ever the group want to
call it.
Thanks for the help.
Regards Bob
-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: 26 April 2000 05:43
Subject: Re: Formula for self C of a Coil (not Medhurst)
>Original Poster: "Barton B. Anderson" <tesla123-at-pacbell-dot-net>
>
>
>>
>> Original Poster: "Robert Jones" <alwynj48-at-earthlink-dot-net>
>
>Hi Bob,
>
>Try this. It's what I use. (a Medhurst derivitive).
>
>K
=(0.585-0.25442*(H/D)+(0.15563*(H/D)^2)-(0.02777*(H/D)^3)+(0.00172*(H/D)^4))
>
>C(pF) = K * D * 2.54
>
>Bart
>>
>>
>> Hi all,
>>
>> Does anybody have the formula or a link for the capacitance of an
isolated
>> cylinder that is not due to Medhurst?
>> Thanks in advance.
>> Regards Bob
>
>
>
>