Patent ID: 8179064

Claim:
An electric motor protection system for protecting an electric motor of a household appliance, the system comprising: a motor speed sensor for sensing a speed of the electric motor; a power control device for controlling the electrical power supplied to the electric motor; a signal processing unit electrically connected to the motor speed sensor and the power control device, the signal processing unit configured to shut off the electric power supplied to the electric motor when the speed sensed by the motor speed sensor is zero or significantly lower than a predetermined target value for a predetermined period of time; wherein when the speed of the electric motor sensed by the motor speed sensor is zero or significantly lower than the predetermined target value, the signal processing unit is configured to control power control device to adjust the power supplied to the electric motor so that the speed of the electric motor is in a desired range of speed values; and the adjustment the power control device makes to the power supplied to the electric motor is proportional to the ratio of the difference between the present speed of the electric motor and a center value of the desired range to the center value of the desired range.