Patent ID: 6064163
Filing Date: 2000-05-16
Classification: H02P

Abstract:
A drive control system for use with a DC brush-less motor having a rotor of a permanent magnet and an associated stator with windings, said drive control system comprising:a switching circuit operable to switch a DC voltage to convert the DC voltage into a series of first pulses; anda controller operable to control said switching circuit so as to apply the series of first pulses to the windings to rotate the rotor;said controller comprisinga voltage detector operable to detect a voltage induced in the windings according to a rotation of the rotor for detecting a position of the rotor or a number of revolutions of the rotor, wherein the induced voltage is formed of a series of second pulses;a duty ratio control operable to control a pulse duty ratio of the first pulses depending upon the induced voltage detected by said voltage detector; anda carrier cycle control operable to control a pulse cycle of the first pulses depending upon the pulse duty ratio or a pulse width of the second pulses.