Abstract: A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit comprises a speed-feedback loop and a torque-feedback loop to control the maximum speed and the maximum torque of the BLDC motor in parallel configuration. The speed-feedback loop generates a speed-control signal. The torque-feedback loop generates a torque-control signal. A PWM circuit receives the speed-control signal and the torque-control signal to generate a PWM signal. A pulse width of the PWM signal is correlated to the level of the speed-control signal and/or the level of the torque-control signal.

Abstract: A mounting structure for fixing an electronic element on a heat dissipation unit is provided. The mounting structure includes a heat dissipation unit, a fixing member, electronic elements and elastic elements. The fixing member is fixed on the heat dissipation unit. The elastic elements are sandwiched between the electronic elements and the fixing member, wherein the fixing member and the elastic elements press the electronic elements to make the electronic elements tightly contact the heat dissipation unit.

Abstract: A speed-control circuit for a BLDC motor is provided. The speed-control circuit includes a pulse generator, a current source circuit, a filter circuit, an error amplification circuit and a PWM circuit. The pulse generator detects a speed signal of the BLDC motor to generate a pulse signal. The filter circuit is coupled to the current source circuit to generate an average signal. The error amplification circuit receives the average signal and a speed-reference signal for generating a speed-control signal. The PWM circuit generates a switching signal to drive the BLDC motor in response to the speed-control signal. A pulse width of the switching signal is determined by the speed-control signal.

Abstract: A parallel PFC converter comprises a first PFC circuit, a second PFC circuit, and a voltage divider. The second PFC circuit is connected in parallel with the first PFC circuit for generating an output voltage of the parallel PFC converter. The voltage divider is coupled to receive the output voltage for generating a first feedback signal and a second feedback signal. The first feedback signal is higher than the second feedback signal. The first PFC circuit and the second PFC circuit respectively comprises a first switching control circuit and a second switching control circuit for regulating the output voltage. It is an object of the present invention to reduce the power loss for improving the efficiency of the PFC converter.

Abstract: A rotating shaft disclosed by the present invention includes a plurality of bumps spacedly formed along an outer circumferential surface thereof. The bumps are each formed with two engagement portions extending outwardly and bilaterally and a deformation space therebetween. The engagement portions undergo resilient deformation toward the deformation space when subjected to a force, thus providing stable engagement with a magnetic body, protecting the magnetic body from cracks and damages during assembling, and enhancing yield. The present invention further discloses a motor rotor having the above-described rotating shaft.

Abstract: A mounting structure for fixing an electronic element on a heat dissipation unit is provided. The mounting structure includes a heat dissipation unit, a fixing member, electronic elements and elastic elements. The fixing member is fixed on the heat dissipation unit. The elastic elements are sandwiched between the electronic elements and the fixing member, wherein the fixing member and the elastic elements press the electronic elements to make the electronic elements tightly contact the heat dissipation unit.

Abstract: A dual-switch flyback power converter includes a control circuit to generate a switching signal. A high-side driving circuit includes a pulse generation circuit. The pulse generation circuit generates a pulse-on signal and a pulse-off signal to control two transistors in response to the switching signal. The two transistors further respectively provide a level-shift-on signal and a level-shift-off signal to a comparison circuit to enable/disable a high-side driving signal. Without using a charge pump circuit to power the high-side driving circuit, a floating winding of a transformer is utilized to provide a floating voltage to power the high-side driving circuit, which reduces the cost of the dual-switch flyback power converter and ensures a sufficient high-side driving capability of the high-side driving circuit.

Abstract: A motor rotor is provided. The motor rotor includes a plurality of magnetic members circumferentially disposed on a peripheral wall surface of a turning axle of the motor rotor, and both end surfaces of the turning axle are coupled with fastening members respectively; each of the magnetic members has a first fastening portion formed at each of its two ends; and the fastening member is provided with a plurality of second fastening portions corresponding in position to the first fastening portions, such that each of the magnetic members are firmly fixed in position to the turning axle.

Abstract: A power management interface is provided and includes a switch, a transmitting circuit, and a receiving circuit. The switch is coupled to an AC power line for controlling a power line signal to a load. The transmitting circuit generates a switching signal to control the switch and achieve a phase modulation to the power line signal in response to a transmitting-data. The receiving circuit is coupled to receive the power line signal for detecting a phase of the power line signal and generating a receiving-data to control power of the load. The receiving-data is generated in accordance with the phase detection of the power line signal and correlated to the transmitting-data.

Abstract: A motor structure and a fan are provided. The motor structure includes a shaft, a motor control panel, a stator, a rotor and a motor housing. The motor control panel has a first fastening portion and is engageable with the shaft. The stator has a second fastening portion coupled to the first fastening portion so as to fasten the motor control panel to the stator, thereby reducing the overall size and saving costs of materials. The rotor corresponds in position to the stator and is pivotally connected to the shaft. The motor housing is pivotally connected to the shaft and encloses the shaft, the motor control panel, the stator, and the rotor. The fan includes the motor structure and a fan blade element.

Abstract: A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit determines the maximum torque and the maximum speed of the BLDC motor. The control circuit includes an over-current detection circuit to generate a reset signal in response to a switching current of the BLDC motor. The reset signal is generated when the switching current of the BLDC motor exceeds a threshold. A pulse width of the PWM signal is correlated to the level of a speed-control signal and the level of the torque-control signal. The pulse width of the PWM signal is also controlled by the reset signal generated by the over-current detection circuit.

Abstract: An end cover adapted to engage with an end surface of a spindle of a motor rotor is proposed for securely coupling to the spindle with a plurality of permanent magnets disposed around the peripheral wall of the spindle. The end cover has a first surface facing an end surface of the spindle and an second surface opposing to the first surface, which is formed with a plurality of inserting slots indentedly disposed around the rim thereof and corresponding to the permanent magnets for coupling the ends of the permanent magnets, thereby securely fastening each of the permanent magnets to the spindle of the motor rotor. Further, the present invention further provides a motor rotor having the end covers described above.

Abstract: A sensor fastening method and a sensor fastening frame for use therewith are provided. The sensor fastening frame is coupled to a motor stator of a brushless motor having distributed coils and extends over the distributed coils to allow the sensor fastening frame to rotate about the axle of a motor rotor, without interference with the distributed coils. At least a sensor is fastened in position to the sensor fastening frame proximate to one end of the axle of the motor stator for positioning the sensor to detect magnetic field variations of the motor rotor.

Abstract: A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit comprises a speed-feedback loop and a torque-feedback loop to control the maximum speed and the maximum torque of the BLDC motor in parallel configuration. The speed-feedback loop generates a speed-control signal. The torque-feedback loop generates a torque-control signal. A PWM circuit receives the speed-control signal and the torque-control signal to generate a PWM signal. A pulse width of the PWM signal is correlated to the level of the speed-control signal and/or the level of the torque-control signal.

Abstract: A motor rotor is provided. The motor rotor includes a plurality of magnetic members circumferentially disposed on a peripheral wall surface of a turning axle of the motor rotor, and both end surfaces of the turning axle are coupled with fastening members respectively; each of the magnetic members has a first fastening portion formed at each of its two ends; and the fastening member is provided with a plurality of second fastening portions corresponding in position to the first fastening portions, such that each of the magnetic members are firmly fixed in position to the turning axle.

Abstract: A rotating shaft disclosed by the present invention includes a plurality of bumps spacedly formed along an outer circumferential surface thereof. The bumps are each formed with two engagement portions extending outwardly and bilaterally and a deformation space therebetween. The engagement portions undergo resilient deformation toward the deformation space when subjected to a force, thus providing stable engagement with a magnetic body, protecting the magnetic body from cracks and damages during assembling, and enhancing yield. The present invention further discloses a motor rotor having the above-described rotating shaft.