Calculation of skin depths and eddy-current power losses for magnetic position sensors

We present a theoretic model to calculate skin depths and eddy-current powe r losses for a magnetic position sensor. Eddy-current, arised from the oper ation of an alternating-current excitation, induces secondary currents and fields between magnetic material and magnetic position sensor. In this pape r, a magnetic position sensor system is simplified to be an outer-winding t oil along the axial direction of a low carbon steel bar. The analytical mod el is derived from basic field and circuit theory considering a linear appr oximation for a nonlinear permeability. Thus the skin depths and eddy-curre nt power losses from the model in eddy-current modeling techniques at vario us frequencies of an excited current source can be calculated. The proposed configuration is capable of predicting the skin depths and eddy-current po wer losses for a magnetic position sensor and has a consistence with experi ments.