Selection and Test of Power Line Filters for Use in Equipment Designed to Meet Government Electromagnetic Compatibility Specifications

This paper reviews the most widely used conducted interference requirements imposed on electronic equipment. Comparative test methods have been devised to evaluate EMI filters using equivalent input and output load conditions. Using these test methods, a design engineer can obtain more realistic data and a better confidence level in meeting the applicable electromagnetic interference and susceptibility requirements. Revision of MIL-F-15733 and MIL-STD-220 is suggested to incorporate a more precise test method to determine normal operating insertion loss (db) criteria on EMI filters. These proposed test methods would correlate more precisely to EMI conducted measurements than the present 50 ohm system test requirements of using buffer networks or no load conditions.