HIGHLY EFFICIENT POWER SUPPLY UNIT AND METHOD FOR SUPPLYING POWER USING SAME

A highly efficient power supply unit and a method for supplying power using same are disclosed. The power supply unit comprises: a relay for switching alternating current power supplied from a plurality of sources; a direct current power supply for converting the switched current power to direct current power; and a controller for generating a switch signal so as for the relay to switch the sources on the basis of the result for monitoring the alternating current power supplied from the sources.