The filter is a frequency selection device, which can make specific frequency components in the signal pass through, and greatly attenuate other frequency components. By using this frequency selection function of the filter, the interference noise can be filtered or the spectrum can be analyzed. In other words, any device or system that can make a specific frequency component of the signal pass through and greatly attenuate or suppress other frequency components is called a filter. Safety regulation Y1 capacitor, Y2 capacitor, ceramic capacitor, multilayer ceramic capacitor, ribbon safety regulation ceramic capacitor are widely used in the filter industry.