Frequency converters, switching power supplies, and lighting system drivers are often sources of interference in power grids. Some of the EMC interference is mitigated directly at the sources of interference by special filter circuits. However, the remaining interference can propagate and amplify via the supply and control lines. This can have unpredictable effects on controllers, power supplies, sensors, and actuators. Our filters limit the interference directly in front of the potentially susceptible equipment or the sensitive end devices.