Abstract: Utilizing an asymmetric magnetic field caused by a mechanism design between a motor rotor and a stator to induce a BEMF, a method for starting a fixed rotation direction of single-phase sensorless DC brushless motor, includes: power-on starting a motor control circuit; if the motor is not in a rotating state before starting the excitation, executing a static starting procedure; then, if the motor rotation direction conforms to a predetermined direction, executing a normal driving procedure; otherwise, executing a static starting procedure. The static starting procedure, by discharging remnant energy of the motor, achieves the purpose of star-up by performing the steps of first phase excitation, stop excitation, and strong second phase excitation. In the normal driving procedure, the slope of BEMF signal of the first phase or the second phase is taken out periodically to detect the motor rotation direction.

Abstract: The invention utilizes an asymmetric magnetic field caused by a mechanism design between a motor rotor and a stator to induce a BEMF, and discloses a method for starting a fixed rotation direction of single-phase sensorless DC brushless motor, including: power-on starting a motor control circuit; if the motor not in the rotating state before starting the excitation, executing a static starting procedure; then, if the motor rotation direction conforming to the predetermined direction, executing a normal driving procedure; otherwise, executing a static starting procedure. The static starting procedure, after of static starting by discharging remnant energy of the motor, achieves the purpose of star-up by performing the steps of first phase excitation, stop excitation, and strong second phase excitation. In the normal driving procedure, the slopes of BEMF signal of the first phase or the second phase is taken out periodically to detect the motor rotation direction.

Abstract: The invention discloses a driving method for single-phase DC brushless motor using sensor only in start-up, comprising: power-up to activate a motor control circuit of a motor; confirming whether the motor is in a rotating state before activation of an excitation? If not, executing a static start-up procedure of using a sensor to detect magnetic poles of the rotor; calculating slope of the BEMF signal to determine the rotation direction of the motor; determining whether the rotation direction of the motor conforming to a predetermined direction; if yes, executing a normal driving procedure; otherwise, executing the static start-up procedure of using a sensor to detect magnetic poles of the rotor. The invention utilizes the present invention utilizes an asymmetric magnetic field caused by a mechanism between a rotor and a stator of a motor to induce a back electromotive force signal and a sensor detection to control rotation direction.

Abstract: A pull bar is adapted for attachment to one end of a screen of a sunshade device beneath a sunroof of a vehicle. The pull bar includes an upper strip body and a lower strip body. The upper strip body is adapted to abut against an upper surface of the screen. The lower strip body is adapted to abut against a lower surface of the screen. The upper and lower strip bodies cooperatively define at least one air flow passage that extends through the upper and lower strip bodies to permit air to flow into or out of the vehicle.

Abstract: A pull bar is adapted for attachment to one end of a screen of a sunshade device beneath a sunroof of a vehicle. The pull bar includes an upper strip body and a lower strip body. The upper strip body is adapted to abut against an upper surface of the screen. The lower strip body is adapted to abut against a lower surface of the screen. The upper and lower strip bodies cooperatively define at least one air flow passage that extends through the upper and lower strip bodies to permit air to flow into or out of the vehicle.