Patent ID: 7143743
Filing Date: 2006-12-05
Classification: F02D

Abstract:
1. A valve position controller comprising: a brushless motor having three-phase stator coils constituting an armature winding, and a magnet rotor disposed so as to rotate relative to the stator coils and holding a plurality of permanent magnets for constituting field poles; a valve driven by the brushless motor; rotor position detection means for producing signals corresponding to the rotational position of the magnet rotor relative to the three-phase stator coils; valve position calculation means for calculating the present position of the valve based on the signals output from the rotor position detection means; control quantity calculation means for calculating the valve position control quantity to eliminate the difference between the present position of the valve calculated by the valve position calculation means and the target control value, and for calculating the motor current control quantity based on the calculated valve position control quantity; and a motor drive circuit for selectively driving the stator coils of two phases among the stator coils of the three phases based on signals output from the rotor position detection means and on the motor current control quantity calculated by the control quantity calculation means.