| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotation angle detection device for detecting the rotation angle of a detection object with a high accuracy even though there is an amplitude deviation in an output signal of a magnetic detection element.SOLUTION: An amplitude deviation correction circuit 40 converts signals from a first hole element 31 and a second hole element 32 into a reference signal (Cos signal) of an amplitude A and an amplitude correction object signal (Sin signal) of an amplitude A' in which the phase is shifted by 90°, generates a pulse signal representing the positive and the negative of the Sin signal by a pulse signal generation circuit 43, generates an amplitude correction signal (Sin' signal) fully wave rectified by shifting the phase of the Cos signal by 90° with an amplitude correction signal generation circuit 44, generates a signal after amplitude correction (Sin'' signal) of the amplitude A by subjecting the pulse signal and the Sin' signal to multiplication processing with a multiplication processing circuit 45, and generates a reference signal (Cos' signal) obtained by delaying the Cos signal with a delay circuit 46. An arc tangent calculation is performed by a rotation angle calculation circuit 50 based on the Cos' signal and the Sin'' signal having the same amplitude A and no phase deviation, and a rotation angle is detected.SELECTED DRAWING: Figure 2 |
