Power tool and control method thereof

A control circuit, comprising:

• a motor;
• a controller, wherein the controller comprises a first controller and a second controller;
• a power supply interface configured to be connected to a power supply;
• an auxiliary power supply circuit configured to power on the controller;
• a signal switch triggerable by a user to switch a power on/off state of a power tool;
• a signal detection circuit connected between the signal switch and the controller configured to output a detection signal according to a connection state of the signal switch, wherein the detection signal caused to be output is one of a power-on signal and a power-off signal;
• a power-on control switch connected between the auxiliary power supply circuit and the second controller configured to control a power-on state of the second controller;
• and
• a driver circuit connected between the second controller and the motor, comprising plural semiconductor switch elements, configured to switch an energized state of the motor;
• wherein the first controller is electrically connected to at least the power-on control switch and is configured to control an on/off state of the power-on control switch, the second controller is connected to at least the signal detection circuit, the power-on control switch, and the driver circuit and is configured to control on/off states of the switch elements in the driver circuit, the first controller is configured to control the power-on control switch to be turned off so that the second controller is de-energized and the motor stops rotating when the signal detection circuit outputs the power-off signal, and the second controller is configured to control the switch elements in the driver circuit to be turned off so that the motor stops rotating when the signal detection circuit outputs the power-off signal and the power-on control switch still remains on.

A control method of a power tool, wherein the power tool comprises a power supply interface connected to a power supply, a controller, an auxiliary power supply circuit, comprised of a first controller and a second controller, configured to power on the controller, a motor, a signal switch triggerable by a user to switch a power on/off state of the power tool, a power-on control switch connected between the auxiliary power supply circuit and the second controller and configured to control a power-on state of the second controller, and a driver circuit connected between the second controller and the motor to switch an energized state of the motor and comprising plural semiconductor switch elements, the first controller is electrically connected to at least the power-on control switch and is configured to control an on/off state of the power-on control switch, the second controller is connected to at least a signal detection circuit, the power-on control switch, and the driver circuit and is configured to control on/off states of the switch elements in the driver circuit, and the control method comprises:

• in a case where the signal detection circuit outputs a power-off signal, controlling, by the first controller, the power-on control switch to be turned off so that the second controller is de-energized and the motor stops rotating;
• and
• in a case where the signal detection circuit outputs a power-off signal and the power-on control switch still remains on, controlling, by the second controller, the switch elements in the driver circuit to be turned off so that the motor stops rotating.