| 摘要 |
PURPOSE:To ensure an assured detection of the revolving direction with a simple constitution, by driving a D type flip-flop with the pulse signal corresponding to a detection output having a cycle corresponding to the number of revolution and a phase different by pi/2. CONSTITUTION:Detection pulses (c) and (d) having a cycle corresponding to the number of revolutions given from waveform shaping circuits 4 and 5 with a phase different by pi/2 are applied to both D terminal and clock terminal Cp of a D type flip-flop FF6. Accordingly the FF6 is triggered by the pulse (d) in the forward turn mode when the pulse (c) is at a high level. Then the Q output of the FF6 is set at a high level. In the backword turn mode, the Q output is always set at a low level since the trigger timing caused by the pulse (d) is different. Thus the Q or -Q output of the FF6 ensures an assured detection of the revolving direction with a simple constitution. |
