Invention Grant
US07795828B2 Back electro-motive force (BEMF) commutation and speed control of a three-phase brushless DC (BLDC) motor 有权
三相无刷直流(BLDC)电机的反电动势(BEMF)换向和速度控制

Back electro-motive force (BEMF) commutation and speed control of a three-phase brushless DC (BLDC) motor
Abstract:
A DC motor comprises a stator having at least three windings coupled to a neutral point; a first pair of upper and lower switches for driving a first winding of the at least three windings to a first voltage or in tristate; a second pair of upper and lower switches for driving a second winding of the at least three windings to a second voltage or in tristate; a third pair of upper and lower switches for driving a third winding of the at least three windings to a third voltage or in tristate, one of the first, second or third windings being in tristate; a back electro-motive force (BEMF) signal generation circuit coupled to receive a BEMF voltage from the winding in tristate; a comparator coupled to receive the BEMF voltage and a zero-crossing voltage representing the voltage at the neutral point at a predetermined time and for comparing the BEMF voltage and the zero-crossing voltage to generate a comparison result; a zero-crossing voltage generation circuit to output the zero-crossing voltage to the comparator; and a commutation controller coupled to receive the comparison result and a speed control signal and for using the comparison result and the speed control signal to generate complementary pulse width modulated (PWM) control signals, one of the complementary PWM control signals for controlling an upper switch and the other of the complementary PWM control signals for substantially simultaneously controlling a lower switch.
Information query
Patent Agency Ranking
0/0