Abstract: Disclosed is a linkage limiting assembly applied in a vacuum cleaner, which is mounted within a frame of the vacuum cleaner. The linkage limiting assembly includes a triggering button arranged at the rear end of the frame, a pushing member configured to push an electric fan assembly or a dust barrel of the vacuum cleaner upwards, a limiting member configured to limit the maximum stroke of the electric fan assembly or the dust barrel, and a linking member connecting the triggering button with the limiting member in a force transmission manner.

Abstract: A handheld vacuum cleaner includes a frame, and a dust barrel and a locking portion mounted on the frame, wherein a front end of the dust barrel and the locking portion are movable relative to each other and are arranged opposite to each other; the dust barrel has a rotatable front cover at a front side thereof; and when the locking portion and the dust barrel move with respect to each other, the front cover is automatically rotatable to open, or close on the front side of the dust barrel due to limit by the locking portion.

Abstract: A method and a system for detecting a logic level of a rotor of a motor, and a motor are disclosed. The method comprises: obtaining an analog voltage output by a position sensor for a winding of the motor; setting a first commutation voltage and a second commutation voltage; generating a logic level according to the analog voltage, the first commutation voltage and the second commutation voltage; and performing angle correction on the logic level according to a first angle corresponding to the first commutation voltage and a second angle corresponding to the second commutation voltage. The first commutation voltage is a commutation voltage for triggering a rising edge, and the second commutation voltage is a commutation voltage for triggering a falling edge. This method may accurately identify the logic level corresponding to the motor rotor, improve uniformity of a commutation voltage and prevent fluctuations in motor speed.

Abstract: A handheld vacuum cleaner includes a frame, and a dust barrel and a locking portion mounted on the frame, wherein a front end of the dust barrel and the locking portion are movable relative to each other and are arranged opposite to each other; the dust barrel has a rotatable front cover at a front side thereof; and when the locking portion and the dust barrel move with respect to each other, the front cover is automatically rotatable to open, or close on the front side of the dust barrel due to limit by the locking portion.

Abstract: Disclosed is a linkage limiting assembly applied in a vacuum cleaner, which is mounted within a frame of the vacuum cleaner. The linkage limiting assembly includes a triggering button arranged at the rear end of the frame, a pushing member configured to push an electric fan assembly or a dust barrel of the vacuum cleaner upwards, a limiting member configured to limit the maximum stroke of the electric fan assembly or the dust barrel, and a linking member connecting the triggering button with the limiting member in a force transmission manner.

Abstract: A method and a system for detecting a logic level of a rotor of a motor, and a motor are disclosed. The method comprises: obtaining an analog voltage output by a position sensor for a winding of the motor; setting a first commutation voltage and a second commutation voltage; generating a logic level according to the analog voltage, the first commutation voltage and the second commutation voltage; and performing angle correction on the logic level according to a first angle corresponding to the first commutation voltage and a second angle corresponding to the second commutation voltage. The first commutation voltage is a commutation voltage for triggering a rising edge, and the second commutation voltage is a commutation voltage for triggering a falling edge. This method may accurately identify the logic level corresponding to the motor rotor, improve uniformity of a commutation voltage and prevent fluctuations in motor speed.

Abstract: Provided are a protection circuit for a brushless DC motor, and a control device. The protection circuit is applied to a control device for a brushless DC motor, the control device including a main control chip and a protection circuit for driving a brushless DC motor. The protection circuit includes a sampling signal input end (RNF), a first resistor (R1), a first capacitor (C1), a second capacitor (C2), a comparator (IC2) and a switching element (IC1), connected together in a preset structure.

Abstract: Provided are a protection circuit for a brushless DC motor, and a control device. The protection circuit is applied to a control device for a brushless DC motor, the control device including a main control chip and a protection circuit for driving a brushless DC motor. The protection circuit includes a sampling signal input end (RNF), a first resistor (R1), a first capacitor (C1), a second capacitor (C2), a comparator (IC2) and a switching element (IC1), connected together in a preset structure.