An Analysis of k ii Coupling Coefficients
Valner João Brusamarello, Yeddo Braga Blauth · International Journal of Electrical Engineering Education · 2012
The mutual inductance and the coupling coefficient for a couple of coils are usually described by simple parameters M and K respectively, instead of M 12 , M 21 and k 12 and k 21 . Many electric circuits theory books present at least a chapter about mutual inductance, in which a proof of M 12 = M 21 = M is usually described. Since most applications of M aim to transfer energy between coils, a coupling coefficient K is usually assumed without the rigorous analysis of k 12 and k 21 . This paper presents an analysis of the mutual inductance between two coupled coils based on the linear magnetic circuit theory and a theoretical proof that it is not necessarily the case that k 12 = k 21 as many books assume. Finally, a practical experiment is presented to confirm the theoretical analysis.