| 摘要 |
PURPOSE:To perform detection excellent in high speed response, by a method wherein two rotary detection elements are provided with respect to a rotor so as to leave a predetermined angle therebetween and respectively obtained level changing directions and polarities are detected while the code of the other level changing direction is selected corresponding to one polarity. CONSTITUTION:Rotation detecting elements 2A, 2B are arranged with respect to the magnet rotary plate 3 integrally rotated along with a rotor so as to hold the 90 deg. angle interval therebetween. Rotation detecting signals S11, S12 are respectively supplied to level change detecting circuits 4A, 4B and level difference S13, S14 are applied to an absolute value comparison circuit 5 and level difference code detecting circuits 6A, 6B. In addition, the signals S11, S12 are applied to level code detecting circuits 7A, 7B. A direction detecting signal forming circuit 8 has switch circuits 11-13 and the circuits 11, 12 are selectively changed over by the output levels of the circuits 7B, 7A while the circuit 13 by the output level of the circuit 15. As mentioned above, a larger one is selected among the level change components of the signals S11, S12 to judge a rotation direction and the rotation direction can be almost always detected. |
