| 摘要 |
PROBLEM TO BE SOLVED: To perform safe driving by surely detecting zero crossing even during PWM control and simplifying processing required for recognizing the position of a rotor by generating the rotor position signal, where the level changes for each zero crossing. SOLUTION: This control device of a brushless motor is provided with a drive control circuit for switching the conduction of each stator coil winding, a PWM carrier generating means for outputting a PWM control signal, a drive pattern generating means for controlling conduction, inaccordance with a drive pattern corresponding to a current phase and a PWM control signal, a comparison means for comparing the reference voltage with the terminal voltage of the stator coil winding for outputting a comparison signal, an enable signal generation means for outputting a latch cancellation signal while the PWM control signal is on, and a latch means for outputting, as a rotor position signal, a comparison signal while no latch cancellation signal is being outputted and a comparison signal, when the latch cancellation signal is being outputted immediately before, while no latch cancellation signal is being outputted. |
