In a system, a plurality of motors are provided. Each of the plurality of motors has a plurality of phase windings. Each of the plurality of motors is rotated when a unidirectional current is supplied to each of the plurality of phase windings thereof. A motor select unit includes a plurality of selectors connected to the plurality of motors, respectively. The motor select unit selects at least one of the plurality of motors via a corresponding at least one of the selectors. A phase current supplier is connected in series to each of the plurality of selectors. The phase current supplier supplies a direct current as the unidirectional current to each of the plurality of phase windings of the selected at least one of the plurality of motors via a corresponding at least one of the selectors.