Analysis of the Magnetization Effect of Permanent Magnets on the Nonlinear Magnetic Characteristic Distributions of a Balanced Armature Receiver

Balanced armature (BA) receivers are widely used due to their small size and good performance. The magnetization of the permanent magnets (PMs) affects the nonlinear magnetic characteristics, which can affect the performance of a BA receiver. In this paper, four different magnetizations were simulated to examine the influence of magnetization on the cogging force, force factor, inductance, and speedance. The simulation results show that the nonlinearity is more obvious with larger magnetization of the PMs and approach a limit when there is saturation in the magnetic circuit. In addition, within a small vibration position or current range, the influence of the magnetization on the cogging force, force factor, and speedance can be treated as linear, and there is no influence on inductance. Based on the simulated nonlinear magnetic characteristics, the vibration displacement can be solved with coupling analyses. The cogging force also affects the displacement resonance frequency. The force factor has a big effect on the vibration displacement at low frequency. Two samples with different magnetizations were made, and the simulation results were verified experimentally.