| 摘要 |
PROBLEM TO BE SOLVED: To improve detection accuracy of a rotor position in simple and cost-reduced configuration.SOLUTION: A rotational position detection device includes: a magnetic detection section for detecting a magnetic change in the vicinity of a rotor rotating a magnetic pole; a rectangular wave generation circuit for converting an output signal of the magnetic detection section into a rectangular wave signal; a triangular wave generation circuit for converting an output signal of the rectangular wave generation circuit into a triangular wave; an A/D conversion circuit for converting an output signal of the triangular wave generation circuit into a digital signal; processing means which inputs the output signal of the rectangular wave generation circuit and an output signal of the A/D conversion circuit; and storage means for previously storing correspondence information between a rotor position number indicating a rotational position of the rotor and a magnetic detection value number that is a numerical value corresponding to a detection value by the magnetic detection section. The processing means calculates a magnetic detection value number (d) corresponding to an output value of the A/D conversion circuit in accordance with a state of the rectangular wave signal from the rectangular wave generation circuit on the basis of the correspondence information, further, calculates a rotor position number corresponding to the magnetic detection value number (d) and outputs the rotor position number as an absolute rotational position value. |
