Abstract: A power tool includes an output shaft, a motor, a housing, a detection unit, a storage device and a control unit. The output shaft is configured to output a torsion. The motor is configured to drive the output shaft to rotate. The housing is configured to accommodate the motor. The detection unit is configured to detect an operational parameter of the power tool. The storage device is configured to store at least a first threshold corresponding to a first operating condition set and a second threshold corresponding to a second operating condition set. The control unit is communicatively connected to the detection unit and the storage device.

Abstract: A circular saw includes a control unit having a signal processing unit. The signal processing unit is configured to collect a bus current and/or a phase current of the motor and output a second drive signal to the drive circuit after the bus current and/or the phase current of the motor is processed by the signal processing unit, so that the motor charges a battery pack with a charging current less than or equal to 50 A. A control method may independently adjust the current of the motor in the circular saw by optimizing the processing for the phase current and/or the bus current of the motor and feed back electric energy generated by the motor to the power supply to optimize the utilization efficiency of the power supply.