Fast Electromagnetic Analysis of a 3-D Magnetic Circuit in a Balanced Armature Receiver

This paper proposes a lumped parameter method to analyze the nonlinear magnetic characteristics of a magnetic circuit in a balanced armature (BA) receiver with a U-shaped armature. A parallel flux loop is proposed in the equivalent magnetic circuit, which can reveal the internal flux flow of the magnet housing of the receiver. Nonlinear magnetic equations can be obtained and established by Kirchhoff’s current and voltage laws and solved using the under-relaxed Newton–Raphson iteration method while considering the nonlinear magnetic properties of soft magnetic materials. The nonlinear magnetic characteristics can be verified by 3-D finite-element method, including the total force, cogging force, force factor, flux linkage, speedance, and inductance. However, there are still gaps that need to be improved while considering the flux leakage and refraction flux. The proposed method is a simple and fast way to analyze the 3-D magnetic circuit of a BA receiver and can be used in the analysis of a new structure design.