Re: Capacitance of a coil

  Antonio -

  Is the capacitance the same for a coil with the same R and L whether it
has one turn or 1000 turns? I am having difficulty with this. My research
and limited tests indicates the Medhurst equation and equations that do not
include the number of turns or length of wire should be used with caution.

  John Couture


At 06:36 PM 1/14/99 -0700, you wrote:
>Original Poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 
>Tesla List wrote:
>> ... I could of
>> course use Medhurst's formula (is there a table for H/D ratio > 5?), but
>> I wanted to know if there's another way to calc it too.
>> BTW: It's only going to handle metric units!
>Here is a more direct formula, by Medhurst too, and in metric units:
>L=coil length in meters, R=coil radius in meters.
>capacitance=(11.26*L+16*R+76.4*sqrt(R*R*R/L))*1e-12 Farads
>Antonio Carlos M. de Queiroz