The filter function is to effectively filter out the frequency point of a given frequency in the power line or a frequency other than that frequency point, to obtain the power signal of a given frequency or to eliminate the power signal after a given frequency. Use the selected frequency of the filter to filter noise interference or spectrum analysis。
The filter is divided into low-through-filter filters according to the frequency band of the passing signal, allowing a low-frequency or straight-flow pass of the signal, inhibiting the high-frequency fraction or interference and noise; high-through filters, allowing the high-frequency fraction of the signal to pass, inhibiting the low-frequency or straight-through fraction; and signals with a certain range are allowed to pass, inhibiting signals, interference and noise below or above the frequency band, etc。