| 摘要 |
PURPOSE:To improve the accuracy of detection and response by arithmetically operating rotational speed on the basis of the previous readings and current readings of reference-clock counting number and rotational-pulse counting number. CONSTITUTION:The rotational pulses of A phase and B phase from a rotary encoder are input to an edge detector 131 and an up-down detecting section 135 respectively, and the counting number of a free running counter 133 is read and held by a register 134 while using the rising edge of rotational pulses from the circuit 131 as a trigger. The forward rotation and reverse rotation of a motor are discriminated by the detecting section 135 on the output of a signal from the circuit 131, and an output from the circuit 131 is counted by an up-down counter 136 by the output of the discrimination. reference clock number and rotational pulses within one sampling time are computed from the difference of the previous content and current content of the register 134 and an output from the counter 134, and the rotational speed of the motor is arithmetically operated on the basis of the reference clock number and the rotational pulses. |
