Method for operating an electric appliance and electric appliance
AssigneeBraun GmbH
InventorsTorsten Klemm, Ingo Vetter, Uwe Jungnickel
Life of this patent
Estimating the term…
Abstract
An electrical appliance with a resonant motor for driving a vibratory component is provided that has a control unit for driving the resonant motor with a predetermined driving frequency and for measuring the motion-induced voltage of the resonant motor and for determining whether the measured voltage value coincides with a predetermined target voltage value or whether the measured voltage value has crossed over the predetermined target value. The control unit measures the motion-induced voltage at a predetermined time of measurement (tm) within a driving cycle.
Claims14
A method of operating a hand-held electrical appliance selected from the group consisting of an electrical toothbrush and an electrical razor, the appliance comprising a resonant motor for driving a vibratory component, the method comprising the steps of:
- driving the resonant motor with a predetermined driving frequency and constant duty cycle;
- measuring a motion-induced voltage of the resonant motor at a predetermined time of measurement (tm) within a driving cycle;
- determining a phase shift by measuring whether the motion-induced voltage value coincides with or crosses over a predetermined target voltage;
- and
- generating a signal when the measured voltage value has reached or exceeded the target value in response to an increase in mechanical load that causes a phase shift, the signal being selected from the group consisting of an acoustic signal, an optical signal, and a tactile signal.
An electrical appliance with a resonant motor for driving a vibratory component, comprising a control unit for driving the resonant motor with a predetermined driving frequency and constant duty cycle, and for measuring at a predetermined time of measurement (tm) within a driving cycle the motion-induced voltage of the resonant motor and for determining a phase shift by measuring whether the voltage-induced voltage coincides with or crosses over a predetermined target voltage, wherein the electrical appliance comprises an indicator device for outputting a signal when the measured voltage value has reached or exceeded the target value, the signal being selected from the group consisting of an acoustic signal, an optical signal, and a tactile signal, and wherein the motion-induced voltage is caused by an increase of a mechanical load on the resonant motor, the electrical appliance being selected from the group consisting of an electrical toothbrush and an electrical razor.
Dependencies are inferred from the claim text.