an electric power supplier includes an alternating / direct current conversion circuit , a first path , a second path , a switch circuit , and a current detection circuit . the alternating / direct current conversion circuit converts an alternating voltage to a direct voltage . one end of the first path is connected to a first load . one end of the second path is connected to the first path , and the other end thereof is connected to a second load . the first and second paths supply output voltage of the alternating / direct current conversion circuit to the first and second loads . the current detection circuit detects a value of the output current flowing through a node between the first and second paths , and controls the switch circuit , formed in the second path , to electrically connect or disconnect the node to / from the second load , based on a detected current value .