| 摘要 |
PURPOSE:To retain the low and high speed feeding operations of a step motor constantly by controlling the motor at low speed feeding time under an open loop control and at high speed feeding time by a signal from an encoder directly coupled with the step motor under a closed loop control. CONSTITUTION:The output of an open loop drive pulse generator 1 is applied to a ring counter 4 at low speed operating time. A down counter 8 with a load loads the number of spaces to accelerate a motor 5. When the motor 5 is thus accelerated to become constant speed, the stop signal 19 of a speed converter 3 is applied to a pulse generator 1 for braking the motor. At high speed operating time a change signal 18 of the converter 3 is applied to an open/close converter 2 under closed loop control by a feedback signal from an encoder 6. Accordingly, the motor can be retained at constant speed at both high and low speed operating times. Since the signal is fed back at high speed feeding time circumferentially, the torque is effectively used. |
