8A Power Line Filters:

Our Power Line Filter range includes single-phase and three-phase types for industrial, medical and general purpose applications.A power line filter, also called an EMI power line filter, is a passive bi-directional network, which effectively filters out a particular frequency point in the power line, or passes a selected frequency. Designed to block mains-born electromagnetic interference (EMI), power line filters are frequency-selective two-port networks usually comprising inductors, capacitors, and resistors.They operate as reflection filters, which provide high series impedance and low parallel impedance in the filter stop band, severely mismatching noise source impedance and load impedance; thus transmitting the undesired frequency components back to the noise source.

Choosing a power line filter

When selecting the power line filter, three main indicators should be considered: firstly, voltage and current, then insertion loss, and finally, size and structure. Since the filter is typically potted, environment is not a primary concern. However, the temperature characteristics of all potting materials and filter capacitors have some influence on the environmental characteristics of the power filter.Insertion loss is one of the most important technical parameters of an EMI power filter. It should be as high as possible to ensure the safety of the equipment in which the filter is used, and the surrounding environment.Insertion loss is a function of frequency, expressed in dB. Insertion loss of an EMI power line filter includes common mode (CM) insertion loss and differential mode (DM) insertion loss.

Applications for power line filters

EMI power line filters are used in the following applications:

1. Household appliances
2. Military/Aerospace Systems
3. Medical Equipment
4. Computers
5. Energy Management Systems
6. Automotive Battery Charger
7. Industrial Equipment