An apparatus for removing torque ripples comprises a permanent magnet rotor, position sensors, stator armature coils, an operational circuit for effecting an arithmetic operation on detected signals from the position sensors, and a control circuit for driving the stator armature coils. According to another embodiment, an apparatus for removing torque ripples includes a direct-current motor having Y-connected armature coils, a detector for detecting counterelectromotive forces in the direct-current motor, an operational circuit for effecting an arithmetic operation on output signals from the detector, and a transistor for driving the direct-current motor.