LC FILTERING: LC filter is generally known as passive filter, which is a traditional DC power supply harmonic compensation device composed of inductor and capacitor. THREE STAGE FILTERING: Filter board consists of three filtering stages, the first stage LC filtering circuit, the second stage common mode EM filtering, and the third stage LC filtering circuit. INPUT AND OUTPUT PORTS: Power supply filtering board input port IN+ IN‑ (two wire 7.62 terminal input). The output port is output + output ‑ (two wire 7.62 terminal output). COMMON MODE FILTERING: EMI power filter board can filter out harmonics in power supply in single or multiple times, purify DC power supply, common mode filtering. SUPPRESSION: DC EMI power filter can be used to suppress the problem of fast transient group pulse interference with a repetition frequency of several kilohertz at certain user sites.