Patent ID: 8860345

Claim:
An electric household appliance comprising a casing; a laundry drum mounted inside the casing to rotate about an axis of rotation; a three-phase asynchronous motor for rotating said laundry drum; and a sensorless safety system for determining rotation of the rotor of said three-phase asynchronous motor to determine rotation or no rotation of said laundry drum; said sensorless safety system being configured to: supply three direct currents (Ias, Ibs, Ics) to the three stator power phases of the stator of said three-phase asynchronous motor during a predetermined time interval (ΔT) at the end of a power failure, so as to magnetize the rotor of said three-phase asynchronous motor at the end of said power failure; cut off supply of said direct currents (Ias, Ibs, Ics) to said stator at the end of said predetermined time interval (ΔT), whereupon energy accumulated during magnetization by the supplied currents is discharged, and determine the time pattern of at least one of the three induced currents (Iar, Ibr, Icr) induced in said stator in response to magnetizing the rotor; and determine rotation or no rotation of the rotor of said three-phase asynchronous motor at the end of said power failure on the basis of the time pattern of at least one of the three induced currents (Iar, Ibr, Icr) determined.