| 摘要 |
PURPOSE:To enable the display of an azimuth marker for the rotational speed with a simple construction by controlling a counter in various digits through a monostable multivibrator to heighten the azimuth marker revolving speed with a lower resolution in the high rotation. CONSTITUTION:In the normal rotation, output corresponding to the rotational direction of a rotary encoder 1 is counted with a reversible counter 4 for tenth's place digit while a monostable multivibrator 3 is triggered through a delay circuit 2 to stop the counting of a fixed time counter 4 by a Q output thereof. At the same time, a unit digit reversible counter 5 is enabled to count by a low level Q output of the multistable vibrator 3 via an AND gate 11. In the low speed rotation, an output of the encoder 1 is generated in a fixed time after the outputting of the monostable multivibrator and counted with the counter 4, not by the counter 5. On the other hand, in the high speed rotation, the monostable multivibrator 3 is triggered before a certain time passes and hence, counting is performed by the counter 5 not by the counter 4, which lowers the resolution to heighten the revolving speed of the azimuth marker. |
