ROTATIONAL SPEED CONTROL DEVICE FOR MOTOR, MOTOR, AND FOOD PROCESSING APPARATUS

摘要

A rotational speed control device for a motor, a motor, and a food processing apparatus. The rotational speed control device comprises: a rotational speed feedback circuit (10) and a rotational speed control loop (20). The rotational speed feedback circuit comprises a rotational speed sensing unit (11) and a resistance adjusting unit (12). The rotational speed sensing unit is configured to sense a current rotational speed of a motor (M) and output a detected rotational speed signal. The resistance adjusting unit is configured to adjust the total resistance of a resistor unit (21) in the rotational speed control loop according to the detected rotational speed signal. The rotational speed control loop comprises the resistor unit, a first capacitor (C1), a first controllable switch (K1), and a second controllable switch (K2). When the motor is powered on, a power supply (AC) charges the first capacitor by means of the motor and the resistor unit, and the first controllable switch and the second controllable switch are turned on or off under the charging voltage of the first capacitor, so as to adjust the rotational speed of the motor.