This paper dissects a case study of mitigating magnetic field interactions in a system integrating strong magnet and power module. Their assembly generated a noticeable 480Hz tonal noise and the power module shut down. Through a combination of simulations and experimental analysis, we identified the root cause. This interaction led to transformer saturation and amplified mechanical vibrations. Our solution combined several strategies: optimizing inductor and transformer design, strategically placing and orienting components to minimize field coupling, and implementing magnetic shielding.
Introduction: A system integration with a strong magnet caused noise and saturation issues. We present a solution and lessons for engineers. The system includes a power module, a magnet. The magnet's proximity to the power module's magnetic components created interaction challenges. ● Transformer Saturation: The magnet's field disrupts the transformer's normal operation, causing it to saturate and generate saturation current waveforms. ● Mechanical Vibration Amplification: The magnetic interaction intensified the vibrational forces acting upon the inductor caused by its operational current, making the vibrations audible.
Conclusion: This case study highlights the critical need to proactively address magnetic interactions during the design phase, particularly when integrating strong magnets with sensitive electronics. Even seemingly minor interactions can lead to significant acoustic noise and performance degradation. Our multi-pronged approach, combining simulations, experimental validation, and design optimization, successfully mitigated these issues. By sharing our insights and quantifiable evaluation methodology, we aim to equip engineers with the tools to prevent similar challenges and ensure optimal product performance.
