| 摘要 |
PURPOSE:To enable easy detection of the direction of rotation of a rotor with a simple equipment, by checking for the presence of a specific pulse outputted when the rotor rotates in the direction as indicated. CONSTITUTION:When a motor rotates against intension, an A phase pulse train a' and a B phase pulse train b' shifted by 90 deg. are led out of a rotary encoder 10 while a signal C' of the level L is introduced into one input terminal of an exclusive OR gate 12 and the output thereof moves to a signal d'. The signal d' is utilized as clock pulse of an FF16 while introduced into a NOR gate 14 in inversion. On the other hand, the pulse train b' is fetched into a D terminal of the FF16 at the rising of the clock pulse and latched with the FF16 as it is at the level L at the rising of the output signal of the circuit 12 and the outputs thereof are at the levels L and H. The outputs of the NOR gates 14 and 18 remain at the level L and thus, there is no pulse-like output. |
