From Jan 1st , 2001 European Union officially has the detailed standard to the electronic installation overtone, to stipulates above mains input 75W the electronic installation product, all has to pass [EN61000-3-2 (power line harmonics)] the harmonic tests and this has became effective in all European unions countries to import into these countries all need to match this standard. In China from May,2005 PFC regards as the standard function which the electron provides.