| 摘要 |
PROBLEM TO BE SOLVED: To prevent overcurrent from flowing in a motor even if a processing speed is low, in a drive unit for DC brushless motor which uses a controlling method using a digital circuit wherein operations are processed by a CPU, etc. SOLUTION: In this drive unit, the supply of voltage to a motor is controlled by a feedback operation (a speed feedback operation device 32) based on a rotating speed of the motor. By providing this unit with a motor characteristic storing means 34 which stores the data about motor characteristics and an overcurrent protective operation means 23 which finds, based on the data obtained from the motor characteristic storing means 34, a range of supply voltage wherein no overcurrent appears and then compares the obtained range of supply voltage with the supply voltage obtained by feedback operation and corrects the supply voltage for the motor based on the comparison result, the supply voltage obtained by the feedback operation is restricted within the range of supply voltage and current flowed in the motor 4 is limited. By this method, overcurrent is prevented from flowing in the motor whether a processing speed is high or low. |
