摘要 |
A pump drive motor control apparatus controls a motor used for driving a hydraulic pump. Every time the supply of electricity to the motor is resumed (every time the motor control signal changes from a low level to a high level), the apparatus measures a time which the voltage generated by the motor requires to decrease by a predetermined amount, the time indicating the decreasing speed of the generated voltage. The apparatus normally sets the high-level maintenance time, in which the motor control signal is maintained high, to a base time. When a state in which the measured time is not longer than a reference time is detected a predetermined number of times (3 times) or more, the apparatus determines that the load of the pump is heavy. In such a case, the apparatus increases the average rotational speed of the motor by increasing the high-level maintenance time.
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