A conducted interference makes many electronic products into the unqualified products, and conducted interference is a criterion of electronic products for electromagnetic compatibility. Conducted interference is used to measure the electronic products in the process of operation to the entire power grid and send electronic jamming signals. All electronic products for grid electricity would send signal interference during operation, if the jamming signal is too big, it would affect the quality of the whole grid electricity, so as to interfere with the normal running of other appliances. Therefore, conducted interference of electronic products indicators have it's rules.