Flyback架构的EMI 效果通常是比较差的（特别是在不连续工作模式下）,以往常经验来看，充电板以及功率板上的充电部分是整机EMI效果的重要决定因素之一。-Flyback-based EMI effect is usually relatively poor (especially in non-continuous mode) to the usual experience, the charge sheet and power charging part of the whole board EMI effects one of the important determinants. Therefore, in this subject which will be targeted Flyback architecture, analysis of the Noise source, transmission, improve the method. Does not affect the electrical properties to be in the premise, reduce costs and improve EMC performance of the UPS.