POWER TOOL AND CONTROL METHOD THEREOF

摘要

A power tool includes an electric motor, a functional accessory capable of being driven by the electric motor, a detection device for detecting a rotational speed of the electric motor, and a controller for controlling the electric motor with a control signal. The control is operable to estimate a load parameter according to a duty cycle of the control signal and the rotational speed of the electric motor such that the electric motor is caused to be operated by the controller with a lower rotational speed under a lower load and a higher rotational speed under a higher load. detecting the rotating speed 30 S of the electric motor SF NO YES 307 A NO YES 308 AF>I NO setting the rotational setting the rotational setting the rotational setting the rotationa speed to be S3 speed to be S2 speed to be SI speed to be SO 309 31 3 1 3 2