| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of parts and provide a drive circuit with a low-cost configuration. SOLUTION: A current from a DC power supply 1 is applied to each of windings L1 to L3 of a DC brushless motor 5 by an inverter section 3, the inverter section 3 is PWM controlled by inverter control means 11, a current flow direction to each of the windings L1 to L3 is switched in relation to the position of the rotor of the motor 5, magnetic poles of the stator are rotated to one direction and rotating force of the rotor can be obtained. Then, an inverter current flowing through the inverter section 3 is detected by current detecting means CO provided between the power supply 1 and the inverter section 3, a current flowing to a winding by a counter electromotive force occurred in the winding of the motor 5 is derived by performing arithmetic operation based on the value of inverter current by current detecting mean CO, inductance of each winding and resistance, and torque control is performed for the motor 5 by controlling the inverter section 3 in such a manner that the current derived by the inverter current and arithmetic means 13 becomes equal to a value capable of generating a predetermined torque. |
