| 摘要 |
PROBLEM TO BE SOLVED: To provide a step motor control circuit capable of adjusting the value of a holding current at stopping of a step motor, even if a constant current motor driver IC is used. SOLUTION: Upon stopping of a step motor, a step motor drive signal 5 is switched to low. The output pulse of a PWM oscillating circuit 3 is outputted from an OR circuit OR, combined with the stop signal of a drive signal outputting circuit 2 by AND circuits AND 1 to 4, and outputted into a constant current motor driver IC7. Respective phases excited at the time of stopping the step motor 8 are subjected to chopping, based on the duty ratio of the output pulse of the PWM oscillating circuit 3. The value of the holding current flowing in the stopping phase of the step motor 8 becomes smaller than that of the output current of the constant current motor driver IC7 by the off-rate of the duty ratio of the output pulse of the PWM oscillating circuit 3. The value of the holding current can be adjusted by adjusting the duty ratio of the output pulse. |
