Improving Permeability of Ferrite Cores Used in Switch-mode Power Supplies

摘要

In this study two methods are proposed to increase the permeability of ferrite cores used in switch-mode power supply applications. The first method is based on the principle of magnetic shaking where an AC magnetic field is superposed on the magnetic core. This method yields good performance in shielding applications but still facing some technical difficulties in switch-mode power supply applications. The second method is based on superimposing a DC magnetic field component equivalent to the main DC component flowing in the main winding of the switch-mode power supply. This method is verified to reduce the power supply inductor current ripple by 68% while downsizing the core of the winding.