Motor unit and personal care device comprising a motor unit

US11881799B2 · kind B2 · utility

Assignee

• The Braun Corporation · DE

Inventors

• Andre THUNOT · Frankfurt, DE
• Torsten Klemm · Bad Soden, DE

Key dates

• Filing date: Aug 18, 2022
• Grant date: Jan 23, 2024
• Expiry date: Aug 18, 2042

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61C17/34
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A motor unit having a motor having a stator and an armature, the armature being arranged for relative driven motion with respect to the stator. A motor control unit has a supply circuit for providing a supply voltage at the motor to provide a set power level to the motor for driving the armature into motion. A measurement circuit is measuring a value of a physical variable indicative of a current flow through the motor, The motor control unit is arranged to interrupt the provision of the supply voltage by the supply circuit and to dynamically brake the motor during a braking time interval and further to measure the value of the physical variable during the braking time interval. The motor control unit is further arranged to compare the measured value of the physical variable with a target value that depends on the supplied power level and on an intended motion amplitude of the armature, to determine a new set power level in dependence on the comparison result and to subsequently provide the new set power level to the motor.