| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a small polyphase motor control unit and capable of precisely detecting rotational angle. <P>SOLUTION: A three-phase brushless DC motor is equipped with a rotational angle sensor 4 of a Hall effect 120° arrangement method. The rotational angle sensor 4 substitutes three angular voltages for a prescribed mathematical expression whose variables are the angular voltages outputted from three galvano-magnetic devices 41, for numerical calculation to extract three angular signals where an offset voltage is canceled. Thus, a small rotational angle sensor realizes precision detection of angular signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
