MOTOR CONTROLLER, DC MOTOR USING THE SAME, AND PUMP

PROBLEM TO BE SOLVED: To provide a small motor controller which controls the capacity of a motor in a wide range at a low cost, and also to provide a DC motor using this motor controller, and a pump.SOLUTION: The motor controller A has: a position sensor 4 which detects the rotational position of the rotor 52 of a DC motor 5; and a control unit 1 which controls the energization angle of each winding 51 of the DC motor 5 based on the detection results of the position sensor 4. The control unit 1 has a distributing circuit 12 which decides the reference energization angle of each winding 51 from sensor signals HU, HV and HW outputted from the position sensor 4, and an energization angle control signal generating circuit 11 which decides the energization angle of each winding 51 by changing the reference energization angle in accordance with a capacity variable signal Sig1 inputted from outside.