Patent ID: 6534948
Filing Date: 2003-03-18
Classification: H02P

Abstract:
A driving circuit of a motor having winding of a stator and having a permanent magnet rotor, said motor driving circuit comprising:a power converter for supplying the motor with pulse-width modulated driving power; a means for detecting a magnetic-pole position of the rotor of the motor; a means for detecting a rotational speed of the motor from output of the means for detecting a magnetic-pole position; a means for outputting a deviation of the detected rotational speed of the motor from a speed instruction; a means for generating a plurality of instruction signals in response to the deviation; a signal selection means that selects one of the plurality of instruction signals according to the magnetic-pole position of the motor, and that outputs a selection signal group; a means for generating modulated waves from the selection signal group and a carrier wave signal; and a means for controlling the power converter by means of pulse width modulation according to the modulated waves.