An approach to the operation of inductors and transformers in terms of the field impedance

Electric circuit theory has been developed to such an extent that there is a tendency to overlook the Maxwellian idea that the conductors forming the electric circuit really serve only to guide the energy which resides, for the most part, in the media surrounding the conductors. A generator supplying power to a load via a transformer is an interesting example in which it is very evident that energy is propagated from primary to secondary winding, through the intervening medium, in the form of an electromagnetic wave. The mechanism of this energy transfer is identical with that of wave propagation either along lines or through a continuous medium, and an attempt is made to view the operation of inductors and transformers in this light. Such an approach leads to an equivalent circuit which is very general and which reduces to the usually accepted circuit as a special case. The rationalized metre-kilogramme-second-coulomb system of units has been employed throughout.