Reaction of an L-C filter to a switching-on event

This paper examines the effect of linear filter characteristics on the suppression of transient-type interference, such as that generated by the switching of inductive loads, relay contacts, etc. The requirements for suppression of such emissions are specified in various standards and specifications, e.g., MIL-STD-461C CE07 Method. Although these interference modes are expressed in the time domain, often linear filters are used for their suppression. The performance of these filters in the suppression of such transients is determined by the parasitic characteristics of the filter elements. The analysis of the effects of these characteristics of the filter is the objective of this paper. Based upon predicted voltages and current overshoot values, selection of filter components can be conducted in a well-established manner, and reliable operation of load circuits can be ensured.