A method for operating an electric drivetrain of a working machine is provided wherein the drivetrain comprises a work drive with an electric work motor and a travel drive with an electric travel motor and vehicle wheels, wherein the working machine experiences a speed deceleration from the outside that may result in a braking force acting on the vehicle wheels lower than a driving force acting on the vehicle wheels due to a moment of inertia of the travel motor. The method includes supplying the travel motor with a power in a direction opposite to an operating direction of the travel motor in order to reduce a rotational speed of the travel motor, if it is detected in advance using a situation detection that the braking force acting on the vehicle wheels as a result of the speed deceleration is lower than the driving force acting on the vehicle wheels.

A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

A brake control system of a motor is provided. When a control circuit intends to brake the motor, the control circuit controls a driver circuit to turn off a first high-side switch and a second high-side switch, and to fully turn on the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off one of the first low-side switch and the second low-side switch, and to continually turn on the other one of the first low-side switch and the second low-side switch, for a period of time. Then, the control circuit controls the driver circuit to turn off the other one of the first low-side switch and the second low-side switch, and to turn on the one of the first low-side switch and the second low-side switch, for a period of time.

A power tool, in particular an electric screwdriver, includes (i) a housing; (ii) an electric motor which is located in the housing and by way of which an insert tool located in a tool holder can be rotationally driven; (iii) and a control device which is designed to control a braking process of the electric motor in response to a braking request in order to stop the rotating insert tool. The braking process includes countercurrent braking. A method for braking an electric motor of a power tool, a computer program, and a machine-readable storage medium are also disclosed.

A power tool, in particular an electric screwdriver, includes (i) a housing; (ii) an electric motor which is located in the housing and by way of which an insert tool located in a tool holder can be rotationally driven; (iii) and a control device which is designed to control a braking process of the electric motor in response to a braking request in order to stop the rotating insert tool. The braking process includes countercurrent braking. A method for braking an electric motor of a power tool, a computer program, and a machine-readable storage medium are also disclosed.

A fan brake circuit includes a semiconductor switch unit, a motor, a motor drive circuit, an isolation unit, a charging/discharging unit and a control unit. One end of the motor, the semiconductor switch unit and the control unit serves to receive an input power. When the fan is powered off, the semiconductor switch unit disconnects from the motor and the motor drive circuit receives the operation voltage provided by the charging/discharging unit and transmits the drive signal to the motor, whereby the motor forms a short-circuit to brake. By means of the design of the fan brake circuit, when the fan is powered off, the fan can quickly brake and stop and the cost is lowered.

A fan brake circuit includes a semiconductor switch unit, a motor, a motor drive circuit, an isolation unit, a charging/discharging unit and a control unit. One end of the motor, the semiconductor switch unit and the control unit serves to receive an input power. When the fan is powered off, the semiconductor switch unit disconnects from the motor and the motor drive circuit receives the operation voltage provided by the charging/discharging unit and transmits the drive signal to the motor, whereby the motor forms a short-circuit to brake. By means of the design of the fan brake circuit, when the fan is powered off, the fan can quickly brake and stop and the cost is lowered.

A fan brake circuit includes a semiconductor switch unit, a motor, a motor drive circuit, an isolation unit, a charging/discharging unit and a control unit. One end of the motor, the semiconductor switch unit and the control unit serves to receive an input power. When the fan is powered off, the semiconductor switch unit disconnects from the motor and the motor drive circuit receives the operation voltage provided by the charging/discharging unit and transmits the drive signal to the motor, whereby the motor forms a short-circuit to brake. By means of the design of the fan brake circuit, when the fan is powered off, the fan can quickly brake and stop and the cost is lowered.

A fan brake circuit includes a semiconductor switch unit, a motor, a motor drive circuit, an isolation unit, a charging/discharging unit and a control unit. One end of the motor, the semiconductor switch unit and the control unit serves to receive an input power. When the fan is powered off, the semiconductor switch unit disconnects from the motor and the motor drive circuit receives the operation voltage provided by the charging/discharging unit and transmits the drive signal to the motor, whereby the motor forms a short-circuit to brake. By means of the design of the fan brake circuit, when the fan is powered off, the fan can quickly brake and stop and the cost is lowered.

A vibration generation device includes a stator, and a rotor rotatable around a predetermined axis with respect to the stator and having a weight having a gravity center at a position shifted from the predetermined axis. A control section controls a start-up period maximum voltage value, which is a maximum voltage value of a drive signal to be applied to the vibration generation device in a start-up period, to become larger than a steady operation period voltage value, which is a voltage value of the drive signal to be applied to the vibration generation device in a steady operation period. The control section selects at least one of a pluraity of voltage values as the steady operation period voltage value and sets the duration of the start-up period based on the steady operation period voltage value selected.