Abstract: An electric motor protection system for protecting an electric motor of a household appliance includes a temperature sensor for sensing a temperature of the electric motor, a motor speed sensor for sensing a speed of the electric motor, a current sensing circuit for sensing an electric current supplied to the electric motor, a power control device for controlling the electrical power supplied to the electric motor, and a signal processing unit electrically connected to the temperature sensor, the motor speed sensor, the current sensing circuit, and the power control device. The signal processing unit is configured to make calculations and judgments based on the measurements of the temperature sensor, the motor speed sensor and the current sensing circuit, and a plurality of predetermined values, and to control the power control device accordingly so as to protect the motor from overheating, being overloaded, or driven by excessive current.

Abstract: An electronic hand mixer for processing food materials is provided. The electronic hand mixer includes one or more beaters, a housing, and a drive motor mounted in the housing. The drive motor is adapted to apply rotational force to the beaters. The electronic hand mixer also includes a power control device for controlling electrical power supplied to the drive motor, a keypad for receiving instructions entered by users, a microprocessor for processing and carrying out the instructions and sending signals to the power control device, and a memory for storing the instructions. The instructions include at least one user-defined mixing course for conducting a mixing operation. The user-defined mixing course includes one or more mixing operations, and each of the mixing operations includes a user-defined running speed of the drive motor associated with a user-defined running period of time of the drive motor.

Abstract: A power saving system for a household electric appliance includes a signal processing unit, a step down network having an adjustable impedance for stepping down an input voltage, and an impedance control switch electrically connected with the step down network and configured for controlling the impedance of the step down network. The signal processing unit is electrically connected to impedance control switch and configured to monitor the working condition of the household electric appliance, calculate the current demanded by the household electric appliance at a next moment, and transmit a signal to the impedance control switch so as to control the impedance control switch to adjust the impedance of the step down network according to the calculation.