| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotation angle measuring apparatus using a magnetic convergence plate, which can detect magnetic saturation promptly and reliably.SOLUTION: The rotation angle measuring apparatus comprises: a first Hall element pair 21 detecting a magnetic component in a first direction; a second Hall element pair 22 detecting a magnetic component in a second direction different from the first direction; a third Hall element pair 23 detecting a magnetic component in a third direction different from the first direction and the second direction; and a fourth Hall element pair 24 detecting a magnetic component in a fourth direction different from the first to third directions. The rotation angle measuring apparatus further comprises: an angle calculation section 27 that calculates a first rotational angle &thetas; of a rotary magnet based on output signal intensities of the first Hall element pair 21 and the second Hall element pair 22, and calculates a second rotational angle &thetas;c of the rotary magnet based on output signal intensities of the third Hall element pair 23 and the fourth Hall element pair 24; and a failure detection section 30 that detects a failure of the rotation angle measuring apparatus from the first rotational angle &thetas; and the second rotational angle &thetas;c. |
