Re: eddy current with secondary coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hi Tom,

I'm glad you brought up the Javatc recommendation for wire size. I included 
Malcolm's 6 and 3 skin depth wire size recommendation for close and space 
wound coils. It is only a recommendation. I would do the same as you and 
use the #28 if your looking for a particular geometry and number of turns 
(something's got to give).

The recommendation is only a recommendation. Maybe it would be best to 
think of it as a ballpark guide for wire size. It was never meant to be an 
absolute rule by myself or by Malcolm. I personally like it as a value to 
keep your eyes on during design. Should it be a drastic difference, then 
maybe the user might want to check around to see if there would be serious 
losses (TSSP would be a good place).

Take care,
Bart


>I have the same problem.
>
>I want to build a mini coil with a 2" former for the secondary using at
>least 1000t of 28 AWG wire (aspect ratio ~6:1).
>
>But the (excellent) javatc design tool recommends using 24AWG because of the
>skin depth due to operating frequency and the expected current.
>
>To do that with the same former will push the aspect ratio well over 10:1
>for 1000t, or if I stick to a 6:1 aspect ratio I only get ~600t.
>
>So I'm going to go ahead with the 28AWG wire and see how it turns out.
>
>Tom L.