GB 20943-2007 Minimum allowable values of energy efficiency and evaluating values of energy conservation for single voltage external AC-DC and AC-AC power supplies
1.1 This standard specifies the minimum allowable values of energy efficiency, evaluating values of energy conservation, target minimum allowable values of energy efficiency, test methods and inspection rules of the external power supplies (hereinafter referred to as power supply) used for changing the voltage of AC network into fixed and single low voltage direct current (no greater than 36 V) or low voltage alternate Current (no greater than 36 V) output voltage.
This standard is applicable to the power supplies with rated output power beingno greater than 250W.
1.2 This standard is not applicable to the DC-DC changer