Intake air amount control unit for engine

摘要

An intake air amount control unit for an engine which is inexpensive and has excellent controllability is constituted such that a PWM duty signal output device calculates a phase current value to be applied to each stator winding of a brushless motor based on an opening difference between an actual opening of a throttle valve and a target opening of the throttle valve and outputs a PWM duty signal corresponding to this calculated phase current value. A rotor magnetic pole position learning device detects and learns a magnetic pole position of a rotor of the brushless motor, and an energization stator winding determining device determines a stator winding to be energized from an opening of the throttle valve and the above learned value. A motor drive device supplies a current to the brushless motor based on the above PWM duty signal and an energization phase selection signal corresponding to the determined stator winding to be energized.