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Re: AC wire resistance with proximitry effects



Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Bart,

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hopefully the same one your using.

Rf = [2pi*N^2*a* effective_rho*(sinh(2theta)+sin(2theta)) ]  /
       [effective_sd*Lw*(cosh(2theta)-cos(2theta)) ]

I assume you ask because you are getting something different?

I'm asking because I didn't see a Q equation by Fraga. Only a Rf equation. I'm assuming from subsequent posts that you are using WoL/Rf for Q. I've kept your coil data post and maybe you could say what you used for L (Ldc or Les).



I didn't put theta in radians. The equation appears to be a classic cos(radians(x)), etc... but I got something off in nevernever land when I set it up. I then removed rads and Q popped up where expected. I left it that way.

I'll try to figure this out too cause I see nothing in the theta definition that would suggest degrees (maybe its grads :o)) May have to email Gary on this one.



I have noted that eff_sD is quite a bit higher than other approximations make.

I believe it is altered because of how he stretches a square wire into a rectangular one but not sure of the basis of this. I'll look at his definition more closely.


I'm in the middle of entering coils into the spreadsheet and currently going through Malcolms data concentrating mainly on the closewound coils. A day or so ago I entered Kurt Schraners' data as he made quite a few precise measurements of different h/d coils. I'll send my spreadsheet your way once I get some of Malcolms data logged. I could sure use a check on the implementation.

Sounds good.

Take care,
Gerry R.