A system for motor control comprising: a motor that includes a plurality of pairs of brushes (8, 9); a control module that supplies control currents to the pairs of brushes correspondingly; characterized in that the system further comprises: a plurality of relay units (17, 27) being a first relay unit that switches between a rotating state and a stopping state of the motor and a second relay unit that changes a rotation number of the motor between a lower speed rotation and a higher speed rotation and the first and second relay units connect and disconnect the control currents supplied from the control module so that when each of the relay units (17, 27) is in an ON state where the relay unit connects a control current, the relay unit (17, 27) applies the control current to any one of the pairs of brushes to thereby generate a rotationally driving force, and when the relay unit (17, 27) is in an OFF state where the relay unit (17, 27) disconnects the control current, the relay unit (17, 27) suspends the control current; and a relay changeover portion that changes over between the ON state and the OFF state of the first and second relay units (17, 27), wherein, when one of the relay units (17, 27) is changed over between the ON state and the OFF state by the relay changeover portion so as to select a pair of brushes (8, 9) to which a current is to be applied, the control module changes over the second relay unit to a current-conductive state while temporarily suspending a control current from the first relay unit, so that a reference current equivalent to the control current which has been applied to the first relay unit is supplied from the second relay unit while a control current for variably controlling a rotation number of the motor together with the reference current is outputted from the first relay unit. a motor that includes a plurality of pairs of brushes (8, 9); a control module that supplies control currents to the pairs of brushes correspondingly; characterized in that the system further comprises: a plurality of relay units (17, 27) being a first relay unit that switches between a rotating state and a stopping state of the motor and a second relay unit that changes a rotation number of the motor between a lower speed rotation and a higher speed rotation and the first and second relay units connect and disconnect the control currents supplied from the control module so that when each of the relay units (17, 27) is in an ON state where the relay unit connects a control current, the relay unit (17, 27) applies the control current to any one of the pairs of brushes to thereby generate a rotationally driving force, and when the relay unit (17, 27) is in an OFF state where the relay unit (17, 27) disconnects the control current, the relay unit (17, 27) suspends the control current; and a relay changeover portion that changes over between the ON state and the OFF state of the first and second relay units (17, 27), wherein, when one of the relay units (17, 27) is changed over between the ON state and the OFF state by the relay changeover portion so as to select a pair of brushes (8, 9) to which a current is to be applied, the control module changes over the second relay unit to a current-conductive state while temporarily suspending a control current from the first relay unit, so that a reference current equivalent to the control current which has been applied to the first relay unit is supplied from the second relay unit while a control current for variably controlling a rotation number of the motor together with the reference current is outputted from the first relay unit. a plurality of relay units (17, 27) being a first relay unit that switches between a rotating state and a stopping state of the motor and a second relay unit that changes a rotation number of the motor between a lower speed rotation and a higher speed rotation and the first and second relay units connect and disconnect the control currents supplied from the control module so that when each of the relay units (17, 27) is in an ON state where the relay unit connects a control current, the relay unit (17, 27) applies the control current to any one of the pairs of brushes to thereby generate a rotationally driving force, and when the relay unit (17, 27) is in an OFF state where the relay unit (17, 27) disconnects the control current, the relay unit (17, 27) suspends the control current; and a relay changeover portion that changes over between the ON state and the OFF state of the first and second relay units (17, 27), wherein, when one of the relay units (17, 27) is changed over between the ON state and the OFF state by the relay changeover portion so as to select a pair of brushes (8, 9) to which a current is to be applied, the control module changes over the second relay unit to a current-conductive state while temporarily suspending a control current from the first relay unit, so that a reference current equivalent to the control current which has been applied to the first relay unit is supplied from the second relay unit while a control current for variably controlling a rotation number of the motor together with the reference current is outputted from the first relay unit.