Electromagnetic pollution of electromagnetic interference (ie EMI) is the fourth largest pollution following the air pollution, water pollution and noise pollution, threatening the human health and the safe operation of electrical and electronic equipment. So, to make the EMI filter circuit of electronic ballasts comply with international standards CISPR15-2007 has great practical significance and application value.
A basic electronic ballast include the EMI filter circuit, the rectifier circuit, the filter circuit, the power factor correction circuit, the half-bridge inverter circuit, the starting circuit, the lamp loads and so on.
The EMI filter circuit is mainly used to suppress the EMI interference induced by conduction and radiation. For the electronic ballast, the problem of electromagnetic compatibility is mainly to prevent the high frequency signal conducte out through the power line and interfere with the operation of other electrical equipment. But for the other electrical equipment is generally not normal cause interference to the electronic ballasts (except for the strong electromagnetic interference such as lightning) .