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AssigneeFestool GmbH
InventorsMichael THÜRINGER, Alexander FÜRST, Patrick SCHNELLE, Tobias HOFMANN, Michal CALTA
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A power tool, in particular a hand-held power tool with a tool, an electric motor for driving the tool and a control unit for controlling the electric motor. The power tool is designed for connection to a mains voltage and includes a rectifier arrangement with an intermediate circuit for providing an intermediate circuit voltage based on the mains voltage, the intermediate circuit voltage having a plurality of successive voltage half-waves, the control unit being configured to provide a torque curve for driving the electric motor, the torque curve including a respective torque half-wave for each voltage half-wave, and the control unit being configured to determine an countervoltage induced in the electric motor and, in response to the countervoltage being greater than or equal to the intermediate circuit voltage, to reduce a current torque value of the torque curve.
1-32. (canceled)
A power tool with a tool, an electric motor for driving the tool and a control unit for controlling the electric motor, wherein the power tool is designed to be connected to a mains voltage and comprises a rectifier arrangement with an intermediate circuit for providing an intermediate circuit voltage on the basis of the mains voltage, wherein the intermediate circuit voltage has a plurality of successive voltage half-waves, the control unit being configured to provide a torque curve for driving the electric motor, the torque curve comprising a respective torque half-wave for each voltage half-wave, and the control unit being configured to determine a countervoltage induced in the electric motor and, in response to the countervoltage being greater than or equal to the intermediate circuit voltage, to reduce a current torque value of the torque curve.
A method for operating a power tool with a tool, an electric motor for driving the tool and a control unit for controlling the electric motor, the method comprising the steps:
An arrangement comprising an electric motor for driving a tool and a control unit for controlling the electric motor, wherein the control unit is configured to provide a torque curve for driving the electric motor, wherein the torque curve comprises a respective torque half-wave for each voltage half-wave of an intermediate circuit voltage and wherein the control unit is configured to determine a countervoltage induced in the electric motor and to reduce a current torque value of the torque curve in response to the countervoltage being greater than or equal to the intermediate circuit voltage.
Dependencies are inferred from the claim text.