| 摘要 |
PURPOSE:To attain precise speed control by conducting open-loop control on starting and performing closed-loop control after an entering within a predetermined revolution range. CONSTITUTION:On starting, a changeover switch 34 is connected to the terminal 34a side, and a reference clock signal is brought to the state in which it is transmitted over an address counter 40. Consequently, the revolution of a stepping motor 12 is controlled under open-loop control. When the speed of rotation detected by a rotary encoder 30 reaches the predetermined speed of rotation, the switch 34 is changed over to the terminal 34b side by an output from a digital frequency comparator 32, and a closed loop control system using the rotary encoder 30 as a rotational speed detector is constituted. |
