[TowerTalk] New tool - toroidal ferrite core inductor calculator

[Lux, Jim]

On 6/16/21 12:05 PM, Jim Brown wrote:
> On 6/16/2021 11:45 AM, Lux, Jim wrote:
>> Out of curiosity, what was the spread in apparent parameters?
>
> I'd have to look at the spreadsheets -- it's been three years. But 
> because resonances are involved, f the parameters I measured, Rs, Xs, 
> and Zmag at a given frequency for a 10-turn winding, almost 2:1 for 
> some data points. With respect to fundamental properties, I'd guess 
> that Fair-Rite's 20% number is pretty good. But those fundamental 
> properties from a circuit point of view are mu' (inductance) and mu'' 
> (loss).


There's also the dimensional tolerances on the actual cores, too. The 
cross sectional area and path length.  Nowhere near a 20% effect but 
still, it was surprisingly large when I was doing a notional design at 
work.  Somewhere (perhaps from you) I heard that one of the 
uncertainties is the shrinkage during the firing process, since they're 
not "machined" out of a block of something.