A theory of eddy current limited heads

Abstract

Many video recording heads are fabricated from electrically conductive, magnetic alloys and are operated at frequencies where the skin depth is small compared with head dimensions. We present a novel theory wherein it is assumed that flux flows only in a skin layer which covers all the surfaces of the head. The gap regions are treated as magnetic transmission lines. Computations of the head inductance compare well with experiment. This model is simple enough to be readily applied to the design of other heads made from conductive materials.