| 摘要 |
Three magnetic sensors are arranged around a rotor at predetermined angular intervals about the rotation axis of the rotor. Sinusoidal signals having a phase difference of 120° are output from the magnetic sensors. A rotation angle computing device detects a magnetic pole transition in a first output signal as follows. The rotation angle computing device detects a magnetic pole transition in the first output signal based on a current value of one of the second and third sinusoidal signals, an absolute value of a difference between an immediately preceding value and the current value of the one of the second and third sinusoidal signals being larger than an absolute value of a difference between an immediately preceding value and the current value of the other of the second and third sinusoidal signals, an immediately preceding value of the first sinusoidal signal and a current value of the first sinusoidal signal. |
