On the Design of an Inductance Coil for Audio Frequencies which has the Iron Core with the Air Gap

Abstract

In practice, it is usual for the induetance elements for audio frequencies to employ iron-cored inductances which have an air gap in order to avoid bulky dimensions and to make the ratioes of effective resistances to their reactances as small as possible. In the present paper, we have obtained the length of an air gap theoretically by the help of complex, permeability under a few assumptions, and some relations which are necessary for the design of the ironcored inductance are derived taking the leakage into account. The result of an experimental test is described to assertain the accuracy of the theory.