Abstract: A controller of a brushless DC electric machine having a rotor and at least a stator winding powered by a driving voltage is provided. The controller includes a position sensor, an advance angle control circuit, and a driving circuit. The position sensor is moved along a reverse rotating direction of the rotor by a prepositioned angle for outputting a position signal. The advance angle control circuit receives the position signal and a driving voltage reproduction signal reproduced from the driving voltage and outputs a commutation control signal lagging the position signal by a first delay time. The driving circuit receives the commutation control signal for outputting a driving signal for controlling a commutation of the brushless DC electric machine.

Abstract: A motor control circuit and method thereof serving a coil for controlling the motor. The motor control circuit comprises a separated signal generating circuit generating a separated signal and a comparator comparing a first phase signal from a Hall element or a second phase signal from a phase signal generating circuit with the separated signal. Thus, a motor speed control signal is generated to control the motor. The noise is reduced during controlling the motor.

Abstract: A heat dissipation device and fan module. The fan module is fixed to a fan tray, which has a track with a first engaging portion. A securing member is disposed on a shield, comprising a second engaging portion. The second engaging portion enters the first engaging portion, fixing the fan module to the fan tray. An actuator connects the securing member and the shield. When external force deforms the actuator, the securing member deforms therewith, withdrawing the second engaging portion from the first engaging portion.

Abstract: A fan speed control device includes a controller, a switch and a voltage regulator. The controller detects a rotation speed signal of the fan to generate a first driving signal when the rotation speed signal is relatively higher than a predetermined rotation speed signal and generates the first driving signal and a second driving signal when the rotation speed signal is relatively lower than the predetermined rotation speed signal. The switch is electrically connected with the controller and receives the first driving signal. The voltage regulator, which is electrically connected with the controller, the switch and the fan, receives the second driving signal, and controls the rotation speed of the fan in accordance with the first driving signal and the second driving signal.

Abstract: A fan system and a stopping method for the fan system are provided. The fan system is electrically connected to a power supply and receives the power therefrom. The fan system includes an energy storage apparatus, a motor and a start-up device. The energy storage apparatus receives and stores the power. The motor is electrically connected to the energy storage apparatus and receives the power. The driver is coupled between the energy storage apparatus and the motor to form a control path and generates a driving signal to the motor according to received power. The start-up device is coupled between the energy storage apparatus and the motor to form a power path therewith. When no power is provided to the fan system, the energy storage apparatus releases the stored power and the start-up device generates a start-up signal to the motor in accordance with the released power so as to form a short-circuit loop in the motor to stop the motor.

Abstract: Stator structures are provided. A stator structure includes at least a magnetic conductive layer and at least a first auxiliary magnetic polar layer. The magnetic conductive layer comprises a plurality of first salient poles. The first auxiliary magnetic polar layer is disposed above the magnetic conductive layer, below the magnetic conductive layer, or between two magnetic conductive layers. The first auxiliary magnetic polar layer comprises at least a second salient pole and a third salient pole. The total number of the second and the third salient poles is equal to that of the first salient poles. The second salient pole comprises permanent magnetic material.

Abstract: A magnetic compensation method for a brushless DC motor. The method of magnetic compensation for the motor provides the magnetic element disposed adjacent to the magnetic sensor to compensate the magnetic sensor for an unnecessary magnetic interference, so that the magnetic sensor provides a regular voltage difference to drive the motor.

Abstract: A brushless DC motor and a stator thereof. The stator comprises an upper magnetic pole piece and a lower magnetic pole piece. The upper magnetic pole piece comprises a plurality of upper protruding portions extending toward the lower magnetic pole piece, and the lower magnetic pole piece comprises a plurality of lower protruding portions extending toward the upper magnetic pole piece. The upper protruding portions and the lower protruding portions are substantially spaced apart and alternately arranged. A positioning portion extending from a distal end of each upper protruding portion is located below the magnetic ring of the rotor, to increase the magnetic force therebetween. Alternatively, a positioning portion can be formed between the lower protruding portions of the lower magnetic pole piece and extended to the bottom of the rotor; thus, an axial attraction force can be generated to stabilize the rotor.

Abstract: A fan housing and a fan have stationary blades for guiding airflow. Each stationary blade has at least one airflow-guiding element extending therefrom along the circumference of the fan. The side wall of the airflow-guiding element changes the direction of the airflow so that the airflow at the outlet is fully introduced toward the heat source. Furthermore, the airflow-guiding element regulates the airflow, restrains the turbulent flow at the outlet and on the curved surface of the stationary blade, decreases the noise arising from the turbulent flow, and prevents foreign matter from entering the fan housing so as to protect the inside elements thereof.

Abstract: A fan includes a frame, a motor base, an impeller, an airflow guiding component, and at least one outwardly expanded part. The motor base is disposed in the frame, and the impeller is disposed on the motor base. The outwardly expanded part, connected with the frame, is disposed at an airflow inlet or an airflow outlet, for increasing areas of intake airflow or discharge airflow. One end of the airflow guiding component is connected with the motor base, and the other end is connected with an inner surface of the frame, instead of being connected with the outwardly expanded part, to prevent the fan from forming blocks on the frame during molding process.

Abstract: A main body of a motor stator. The main body includes a cylindrical waist post, a plurality of first salients and a plurality of second salients. The waist post has a first end and a second end. The first salients, spaced at intervals, are connected to the first end and located on a first plane. The second salients, spaced at intervals, are connected to the second end and located on a second plane. When the first salients project onto the second plane along the axial direction of the cylindrical waist post, each projected first salient is located between two adjacent second salients.

Abstract: A motor includes a stator, a rotor, a top magnetic structure, and a bottom magnetic structure. The stator is disposed in a frame. The rotor is also disposed in the frame, corresponding to the stator. The rotor includes a shaft extending axially from the rotor. The bottom magnetic structure is at the bottom of the frame. The top magnetic structure is on the top of the frame. The top and bottom magnetic structures are opposite to each other in an axial direction. Magnetic attraction generated between the first magnetic structure and the shaft, and the second magnetic structure and the shaft positions the shaft therebetween such that the first magnetic structure, the second magnetic structure, and the shaft are coaxially aligned.

Abstract: A heat dissipation module is disclosed. A first heat dissipation apparatus and a second heat dissipation apparatus are symmetrically disposed. A flow direction controlling structure has a rotatable element disposed between the first and second heat dissipation apparatuses and formed an isolation wall thereof, so that the first and second heat dissipation apparatuses respectively have a tunnel. Each of the rotatable elements has a fixed end and a correspondingly movable end for guiding air flow. When outlet pressures of the first and second heat dissipation apparatuses are different, the movable end deflects to the first heat dissipation apparatus or the second heat dissipation apparatus to change outlet areas thereof. The heat dissipation module and the flow direction controlling structure control air flow and prevent backflow, so as to maintain overall outlet area and improve heat dissipation effect of the module.

Abstract: A heat dissipation apparatus. A fan frame includes an air inlet, an air outlet, a passage, and a curved expansion portion. The air inlet is opposite the air outlet. The passage is between the air inlet and the air outlet, guiding airflow from the air inlet to the air outlet. The curved expansion portion is radially and outwardly extended from an inner peripheral wall of the passage at the air inlet or air outlet. An impeller is disposed in the fan frame and includes a plurality of blades. Each blade is disposed in the passage and includes an extension end extending to the curved expansion portion.

Abstract: A fan includes a fan frame and an impeller. The fan frame has a housing, a base and at least one supporting element. The inner wall of the housing has at least one guiding portion in the form of a curved cavity for increasing an airflow intake of the fan, and the base is disposed within the housing and has a bottom portion and a pressurizing portion. The pressurizing portion is disposed around the bottom portion for increasing an air pressure of the fan. The supporting elements are connected to the housing and the pressurized portion of the base. The impeller is disposed within the housing and supported by the base.

Abstract: A fan is disclosed for use in a system, and the system has at least one connection structure. The fan is mainly composed of an impeller and a base, and the impeller is connected to the base. The impeller at least has a hub, a plurality of blades and a driver. The base has at least one engaging member, and the engaging member is corresponding to the connection structure. Further, the fan is fixed on the system by connecting the engaging member and the connection structure together.

Abstract: A motor. The motor includes a stator, a rotor, a top magnetic structure, and a bottom magnetic structure. The stator is disposed in a frame. The rotor is also disposed in the frame, corresponding to the stator. The rotor comprises a shaft, extended axially from the rotor. The shaft does not contact the stator or the frame. The bottom magnetic structure is at the bottom of the frame. The top magnetic structure is on the top of the frame. The top and bottom magnetic structures are opposite to each other in an axial direction. Magnetic attraction generated between the first magnetic structure and the second magnetic structure attracts and positions the shaft therebetween such that the first magnetic structure, the second magnetic structure, and the shaft are coaxially aligned.

Abstract: A heat-dissipating device and its manufacturing process are provided for significantly increasing the number and size of blades so as to enhance the heat-dissipating performance. The heat-dissipating device has a plurality of blades arranged around the hub of the heat-dissipating device and there is an overlapped region formed between every two adjacent blades. A single mold is used to manufacture such a heat-dissipating device so that not only can the manufacturing cost be reduced but it can significantly increase the number and size of blades so as to increase the heat-dissipating efficiency.

Abstract: A centrifugal fan includes a hub and an impeller. The impeller is composed of a plurality of blades mounted around an outer circumference of the hub. The paraxial side of the blade forms a backward leaning structure, while the non-paraxial side thereof forms a forward leaning structure. A chamfer structure also can be formed at a paraxial side of each blade to enlarge the air inlet of the fan. Each blade further includes a protrusion, which is located at a side opposite to the inlet and extends toward a center of the hub, to increase the airflow rate through the fan motor. The centrifugal fan further includes an anti-decompression cap connected to an inlet side of the impeller to prevent an axial flow of the intake air from decompression.

Abstract: A motor includes a first housing, a second housing, a rotor and a stator. The second housing is assembled with the first housing to form an accommodating space. The second housing has a flange adjacent to the connection between the first and second housings. The rotor has a shaft extended outwardly from the second housing and disposed in the accommodating space. The stator is disposed corresponding to the rotor and in the accommodating space. The flange has at least one protruding portion. When the second housing is assembled with the first housing, the protruding portion presses against the stator and is deformed so that the first and second housings are sealed.