| 摘要 |
An electric tool comprises a three-phase brushless motor for driving a tool and a motor driving device for performing rectangular-wave driving of the three-phase brushless motor. In the motor driving device, a conduction angle can be set to a value of 130 to 180 degrees inclusive, and especially, the conduction angle can be changed in at least two steps within the range of 120 to 180 degrees inclusive. In this case, as a load applied to the tool decreases, it is also preferable to set the conduction angle to a larger value. Alternatively, as the load applied to the tool decreases, it is also preferable to set the conduction angle to a smaller value. |
