System of uninterrupted from line type cable (when OFF-LINE UPS) is making power system change, can have changeover time, and change time after all how long? What effect to have to the computer? It is the question that the client often raises. The length that changes time each manufacturer products plan is different, all upright commonly at 2 to 10 millisecond, with respect to the computer character, when electric power is interrupted, the commutative formula power source of its itself is supplied implement Ying Kewei holds 10 millisecond to control, because this is ceaseless,average PC can accept the changeover time of electric system.