Abstract: A method for testing a motor having a rotor and a winding is provided. The method includes steps of (a) providing a power to rotate the rotor to a predetermined speed, (b) removing the power, (c) measuring a terminal voltage of the winding while a current within the winding is zero, (d) obtaining a back electromotive force in the winding by compensating the terminal voltage with a performance of the rotor, (e) selecting a characteristic of the back electromotive force and (f) determining a magnetization of the motor by comparing the characteristic with a predetermined parameter.

Abstract: A permanent magnet motor is provided. The permanent magnet motor includes a stator having a stator shaft having an outer surface, K salient teeth formed upon the outer surface, and K winding slots formed among the K salient teeth, and a rotor having a first inner surface facing the outer surface, and P pairs of permanent magnets formed on the first inner surface, each of which has a second inner surface facing the outer surface and at least a groove formed on the second inner surface to reduce a cogging torque.

Abstract: A rotary structure of a permanent magnet electric machine including a stator and a rotor is provided. The stator has K salient teeth peripherally spaced with equal intervals for forming K winding slots, wherein K is a natural number greater than 1. The rotor has an annular inner surface and has P pairs of permanent magnets peripherally spaced with equal intervals along the inner surface for rotating around the stator, wherein P is a natural number. Each permanent magnet having two sides along a peripheral direction of the rotor includes a pair of inclined surfaces on the two sides, the pair of inclined surfaces is symmetric with respect to a radial plane of the each permanent magnet, and an inclined angle ? between the inclined surface and the radial plane is selected from a range of 90(1?1/(4P))<?<90(1+1/(4P)).

Abstract: This is related to a fan including a casing, a first impeller structure, a second impeller structure, and at least one driving device. The casing has an outlet and an air-containing portion having an entrance and an exit provided inside the casing. The first impeller structure and the second impeller structure are installed inside the casing, and include a first blade set and a second blade set, respectively. The first blade set is located corresponding to the entrance of the air-containing portion. The second blade set is located corresponding to the exit of the air-containing portion. The driving device drives the first and second impeller structures.

Abstract: A driving apparatus for fan motors, electrically connected between a pulse width modulation (PWM) signal generator and a controller, includes a converter electrically connected to the PWM signal generator, generating a first reference voltage according to the duty cycle of a PWM signal generated by the PWM signal generator; a reference voltage generator electrically connected to an external power source, generating a second reference voltage according to the external power source; and a comparator having a first and second input terminal and an output terminal; wherein the first input terminal is electrically connected to the converter, the second input terminal is connected to the reference voltage generator and the output terminal is connected to the controller, and when the first reference voltage is greater than the second reference voltage, a driving signal is output from the output terminal to the controller to control the rotation speed of the fan motor.

Abstract: A heat dissipation system includes at least one fan, at least two controllers, a signal generator, and a signal converter. The controllers are electrically connected to the fan and generate an enable signal according to a feedback signal of the fan. The signal generator is electrically connected to the controllers and generates a control signal according to the enable signal. The signal converter is electrically connected to the signal generator and the fan, converts the control signal to a drive signal to the fan, thereby controlling rotation speed of the fan.

Abstract: A fan assembly comprises a frame and a securing element. The frame has a first end portion, a second end portion and a middle portion. The foam securing element comprises a positioning hole having a first hole having a shape corresponding to the first end portion, a second hole having a shape corresponding to the second end portion, and a third hole having a cross section larger than that of the second hole. When the second end portion is inserted into the first hole, the second end portion and the middle portion pass through the first hole and the first end portion urges against the periphery of the second hole to receive the second end portion in the third hole. The second end portion of the frame is stopped by a periphery of the positioning hole after rotating at a predetermined angle so that the frame is positioned.

Abstract: A cooling fan with high heat-dissipating performance includes a plurality of blades; and a frame for receiving the blades therein, wherein the frame has a reduced height for exposing the blades to outside of the frame so as to allow air to enter into the frame via a top portion and a peripheral portion of the blades to improve air introduction and heat dissipating efficiency of the cooling fan. A cover may be mounted to a top surface of the frame, and formed with a plurality of openings for allowing air to enter into the frame through the openings; such an arrangement cam effectively enhance air intake and working efficiency of the cooling fan.

Abstract: A fan includes a housing, an impeller and a motor. The housing has a main body, a motor base and at least one supporting member disposed between the main body and the motor base. The impeller is disposed on the motor base and has a hub and a plurality of blades disposed around the hub. The motor is connected to the impeller for driving the impeller to rotate. Each of the blades is connected to the hub at a predetermined angle ranging from 22.5 degrees to 36 degrees.

Abstract: A heat dissipating device includes an outer frame, a first rotor, a base, a second rotor and a driving device. The first rotor comprises a shaft, a first hub and a plurality of first rotor blades disposed around the first hub. The base is disposed in the outer frame. The second rotor comprises a plurality of second rotor blades, coupled to the shaft of the first rotor and disposed next to the first rotor. The driving device is supported by the base for driving the first rotor and the second rotor.

Abstract: A terminal element, a motor winding structure and a manufacturing method are disclosed. The terminal element includes a fixing portion, a positioning portion and a buffering portion. The fixing portion is disposed at one end of the terminal element and has a serrate fixing pattern. The fixing portion is connected with a connecting position of the motor winding bobbin. The positioning portion is disposed adjacent to the fixing portion and urged against the motor winding structure for positioning the fixing portion while it is connected with the connecting position. The buffering portion has a first bending and a second bending, and the first bending is connected to positioning portion. The buffering portion absorbs the force applied to the terminal element.

Abstract: A PWM buffer circuit includes a duty cycle converting circuit and a frequency-fixed PWM signal generating circuit. The duty cycle converting circuit is used for receiving a first PWM signal and then generating a duty cycle reference voltage on the basis of the first PWM signal. The duty cycle reference voltage is a one-to-one mapping function of the first duty cycle. The frequency-fixed PWM signal generating circuit is used for receiving the duty cycle reference voltage and then outputting a second PWM signal with a fixed frequency. The second PWM signal has a second duty cycle, which is determined in accordance with the duty cycle reference voltage. In addition, the second duty cycle is a one-to-one mapping function of the duty cycle reference voltage.

Abstract: A wire-fixing element is coupled into an opening of a base. A wire passes through the opening, and one part of the wire is disposed in the base. The wire-fixing element includes a first end and a second end. A pair of arms is disposed at the first end and the arms are buckled into the opening. A supporting member is disposed at the second end and is used for supporting the wire.

Abstract: A fan system includes a first airflow generator providing a main airflow, a duct having a first feeding port to guide the main airflow, and a first fan. The first fan includes a base, a rotor connected to the base by a shaft, and a plurality of blades connected to the rotor. Each blade includes a passive part corresponding to the first feeding port and an active part. The main airflow drives the passive part rotating about the shaft to synchronously rotate the active part, dissipating heat from a heat source, increasing flow rate of airflow and decreasing pressure. The amount and location of the fans can be flexibly configured.

Abstract: A heat-dissipation structure for a motor. The heat-dissipation structure comprises a shaft, a seat and a rotator. The rotator coupled to the seat by the shaft comprises a housing and a cover. The housing comprises an inner side connected to the shaft and a bottom comprising at least one through hole. The cover is connected to an exterior of the bottom of the housing and a distance is formed between the cover and the housing, so that the cover prevents objects from entering the through hole.

Abstract: A serial fan includes a frame, a plurality of rotor vanes, a support connected to the frame through a plurality of connecting parts. The plurality of rotor vanes are arranged in series in the frame along an axial direction and the plurality of connecting parts are disposed therebetween to minimize space occupied by the serial fan in the axial direction, and effectively increase the blast pressure.

Abstract: A fan includes a fan housing and an impeller. The fan housing includes a frame, a base disposed in the frame, a plurality of stationary blades disposed between the frame and the base, and a plurality of airflow-guiding elements extending inward from the frame and toward the base. The airflow-guiding elements and the stationary blades are alternately arranged. The impeller is disposed in the fan housing.

Abstract: A heat-dissipating fan with an upward air-guiding member is provided. The heat-dissipating fan includes a housing, an impeller having a hub and a plurality of blades disposed around the hub, a base disposed inside the housing for supporting the impeller thereon, and an air-guiding member disposed between the base and the housing, wherein the air-guiding member has at least one inclined edge on the windward side or its opposite side relative to the horizontal line perpendicular to the axis of the heat-dissipating fan.

Abstract: A fan system includes a driving device, a speed detecting device and a logic device. The driving device generates a speed detecting signal and a predetermined alarm signal. The speed detecting device, which is electrically connected with the driving device, receives the speed detecting signal, and generates a low speed signal when the speed detecting signal is lower than a reference signal. The logic device is respectively electrically connected with the driving device and the speed detecting device, and generates an alarm signal when the logic device receives the predetermined alarm signal or the low speed signal.

Abstract: An impeller, which is driven by a stator, includes a conducting shell, a hub and a plurality of blades. The conducting shell covers at least one side of the stator. The hub covers the conducting shell. At least one air gap is formed between the hub and the stator. A top portion of the hub has an opening to partially expose a top portion of the conducting shell. At least one airflow passage is formed between an inner wall of the hub and an outer surface of the conducting shell. The airflow passage has at least one inlet connected with the opening and at least one outlet connected with the air gap. The blades are disposed around the circumferences of the hub.