Reduction of conducted emission noise using various power supply filters

A power supply filter is often employed to reduce conducted emission on commercial power lines. It is often designed effectively by introducing some elements of trial and error, based on the designer´s experience, and knowledge on the sources of the emission. In this paper, the effectiveness of a power line filter to reduce conducted emission is presented and discussed. The contributions of the common-mode and differential-mode currents are studied over a given spectrum to determine the critical components of the filter.