A motor drive unit for driving a motor of a motorized window treatment may comprise software-based and hardware-based implementations of a process for detecting and resolving a stall condition in the motor, where the hardware-based implementation is configured to reduce power delivered to the motor if the software-based implementation has not first reduced the power to the motor. A control circuit may detect a stall condition of the motor, and reduce the power delivered to the motor after a first period of time from first detecting the stall condition. The motor drive unit may comprise a stall prevention circuit configured to reduce the power delivered to the motor after a second period of time (e.g., longer than the first period of time) from determining that a rotational sensing circuit is not generating a sensor signal while the control circuit is generating a drive signal to rotate the motor.

The present invention relates to a roller blind and a control device thereof. The control device comprises a reeling mechanism, a solenoid valve, a push mechanism, a front cap, and a damper. After the solenoid valve is energized, the solenoid valve drives the push mechanism to push against the front cap so as to separate the front cap from an engaging portion of the reeling mechanism, and the reeling mechanism is not subject to a resistance of the damper. A curtain fabric is not affected by the resistance of the damper and can be quickly lowered by gravity.

A door braking system includes: a shaft; a brake pad configured to be mounted to the shaft; a plate for mounting on the shaft adjacent to the brake pad; a spring for urging the plate to the brake pad, the spring configured to be mounted on the shaft; a nut dimensioned and sized to be mounted on the shaft for adjusting an amount of force the spring urges the plate against the brake pad. A method of applying variable amount of braking force to a door includes: attaching a brake pad and brake plate to a shaft; configuring a spring to urge the brake plate against the brake pad; mounting an adjustment piece to the shaft; and configuring the adjustment piece to move axially on the shaft as the shaft rotates to thereby vary a force the spring urges against the brake plate.

A door braking system includes: a shaft; a brake pad configured to be mounted to the shaft; a plate for mounting on the shaft adjacent to the brake pad; a spring for urging the plate to the brake pad, the spring configured to be mounted on the shaft; a nut dimensioned and sized to be mounted on the shaft for adjusting an amount of force the spring urges the plate against the brake pad. A method of applying variable amount of braking force to a door includes: attaching a brake pad and brake plate to a shaft; configuring a spring to urge the brake plate against the brake pad; mounting an adjustment piece to the shaft; and configuring the adjustment piece to move axially on the shaft as the shaft rotates to thereby vary a force the spring urges against the brake plate.

An adjustable door braking system includes a shaft, a brake pad configured to be mounted to the shaft, a plate for mounting on the shaft adjacent to the brake pad, a spring for urging the plate to the brake pad, an adjustment piece, and a seat. The spring is configured to be mounted on the shaft. The adjustment piece is dimensioned and sized to be mounted on the shaft for adjusting an amount of force the spring urges the plate against the brake pad. The seat allows the adjustment piece to move axially along the shaft and limit the adjustment piece from rotating with the shaft. The seat is movable between an engaged position where it contacts the adjustment piece to prevent rotation of the adjustment piece and a disengaged position where it does not contact the adjustment piece.

An adjustable door braking system includes a shaft, a brake pad configured to be mounted to the shaft, a plate for mounting on the shaft adjacent to the brake pad, a spring for urging the plate to the brake pad, an adjustment piece, and a seat. The spring is configured to be mounted on the shaft. The adjustment piece is dimensioned and sized to be mounted on the shaft for adjusting an amount of force the spring urges the plate against the brake pad. The seat allows the adjustment piece to move axially along the shaft and limit the adjustment piece from rotating with the shaft. The seat is movable between an engaged position where it contacts the adjustment piece to prevent rotation of the adjustment piece and a disengaged position where it does not contact the adjustment piece.

A motor drive unit for driving a motor of a motorized window treatment may comprise software-based and hardware-based implementations of a process for detecting and resolving a stall condition in the motor, where the hardware-based implementation is configured to reduce power delivered to the motor if the software-based implementation has not first reduced the power to the motor. A control circuit may detect a stall condition of the motor, and reduce the power delivered to the motor after a first period of time from first detecting the stall condition. The motor drive unit may comprise a stall prevention circuit configured to reduce the power delivered to the motor after a second period of time (e.g., longer than the first period of time) from determining that a rotational sensing circuit is not generating a sensor signal while the control circuit is generating a drive signal to rotate the motor.

A motor drive unit for driving a motor of a motorized window treatment may comprise software-based and hardware-based implementations of a process for detecting and resolving a stall condition in the motor, where the hardware-based implementation is configured to reduce power delivered to the motor if the software-based implementation has not first reduced the power to the motor. A control circuit may detect a stall condition of the motor, and reduce the power delivered to the motor after a first period of time from first detecting the stall condition. The motor drive unit may comprise a stall prevention circuit configured to reduce the power delivered to the motor after a second period of time (e.g., longer than the first period of time) from determining that a rotational sensing circuit is not generating a sensor signal while the control circuit is generating a drive signal to rotate the motor.

A motorized window treatment includes a motor drive unit having a motor and a covering material having a first end in a fixed position and a second end movable along a first axis. The covering material is configured to be extended along a first axis when the motor is operated in a first direction and retraced along the first axis when the motor is operated in a second direction. A hembar is coupled to the second end of the covering material. At least one state sensing circuit is coupled to the hembar and is configured to generate at least one first signal. A control circuit is configured to determine a present state of the hembar based on the at least one first signal. The motor drive unit is configured to control the motor when the present state of the hembar and an expected state of the hembar are different.

A motorized window treatment includes a motor drive unit having a motor and a covering material having a first end in a fixed position and a second end movable along a first axis. The covering material is configured to be extended along a first axis when the motor is operated in a first direction and retraced along the first axis when the motor is operated in a second direction. A hembar is coupled to the second end of the covering material. At least one state sensing circuit is coupled to the hembar and is configured to generate at least one first signal. A control circuit is configured to determine a present state of the hembar based on the at least one first signal. The motor drive unit is configured to control the motor when the present state of the hembar and an expected state of the hembar are different.