| 摘要 |
PURPOSE:To obtain position locking force corresponding to high-speed vibrations, by performing count-up or count-down with a hard counter in accordance with the condition of a rotational direction signal and determining a motor driving voltage in accordance with the counted value. CONSTITUTION:A B-phase signal out of output signals of an encoder 14 is inputted into a counting pulse generating circuit 9. The circuit 9 inputs a count pulse which becomes a low level for a fixed time at the rise or fall of the B-phase signal into the up-side or down-side input of a counter 8 through an AND gate 22 or 23. When the counted value of the counter 8 is positive, the output of a DA converter 10 is inverted at a summing amplifier 11 and inputted into a driver 12. Then a servomotor 13 starts to make reverse rotation. Since the counting pulse is generated by the counting pulse generating circuit 9 and the pulse acts as a down-counting pulse at this time, the counted value approaches zero. When the counted value is negative, the counted value also approaches zero. By this operation, the motor 13 works in such a way that the counted value always approaches zero. |
