Awg formula, was "New formula for secondary resonant frequency"

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

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <tesla123-at-pacbell-dot-net>

Paul, Kurt, All, 

Here's another one: 

awg = -8.62448720299999 * log(wd / 0.324557964, 2.718281829) 
where, 
wd = wire diameter in inches 
2.718281829 = base 

Derived a couple years ago to replace my wire table lookup and eventually was
incorporated into JavaTC. If used in Excel, just take out the spaces and
replace wd with a cell reference for wire diameter in inches (Excel understands
the base). 

Pretty close to Pauls, but I think a little better accuracy to nominal awg
dimensions. For example, 18 awg = .0403 inch or 1.0236 mm (nominal). Paul's
shows 17.5 awg. The above formula shows 17.99 awg. Just thought I'd throw it
out there for anyone interested. 

Bart 
  
>
> You can use 
>
>   awg = 1 + log(7.348e-3/wd)/0.115943 
>
> and use this awg in the formula for fa above. 
>
> Regards, 
> -- 
> Paul Nicholson, 
> Manchester, UK. 
> --