| 摘要 |
PURPOSE:To shorten the time of starting and eliminate the affection of the number of rotation by a method wherein a time until the current of a DC motor becomes the driving current of the same is measured and an electric power amplifying circuit is made inert based on the information of the measured time. CONSTITUTION:An incremental and decremental counter 18 effects an incremental operation when an overcurrent detecting signal 16 shows that it is not in an overcurrent condition. A counter controlling reference clock 19 starts counting and a time until the overcurrent detecting signal becomes the overcurrent condition is measured. On the other hand, when the overcurrent detecting signal 16 shows that it is in the overcurrent state, the incremental and decremental counter 18 effects decremental-operation based on a time information till that time. In this case, the counter controlling reference clock 19 is counted to make a power amplifier, not shown in a diagram, inert for a predetermined period of time and a power amplifier inert signal 12 is outputted. Accordingly, the power amplifier is not brought into an inert state unnecessarily even upon starting the operation thereof whereby wasteless control may be effected. |
