Abstract: An optoelectronic device includes a first semiconductor layer, a second semiconductor layer and an active layer between the first semiconductor layer and the second semiconductor layer; a first insulating layer on the second semiconductor layer and including a plurality of first openings exposing the first semiconductor layer, wherein the first openings include a first group and a second group; a third electrode on the first insulating layer and including a first extended portion and a second extended portion, wherein the first extended portion and the second extended portion are respectively electrically connected to the first semiconductor layer through the first group of the first openings and the second group of the first openings, and wherein the number of the first group of the first openings is different from the number of the second group of the first openings; and a plurality of fourth electrodes on the second insulating layer and electrically connected to the second semiconductor layer, wherein in a

Abstract: A power device includes a power factor corrector, an auxiliary capacitor, a switching device, an auxiliary boost circuit, a controller and a voltage conversion device. The switching device has a first end electrically connected to the output end of the power factor corrector, and a second end electrically connected to one end of the auxiliary capacitor. An output end of the auxiliary boost circuit is electrically connected to the output end of the power factor corrector, an input end of the auxiliary boost circuit is electrically connected to a middle end of the switching device, and a ground end of the auxiliary boost circuit is electrically connected to another end of the auxiliary capacitor. The controller is electrically connected to the switching device and the auxiliary boost circuit. The input end of the voltage conversion device is electrically connected to the output end of the power factor corrector.

Abstract: A power device includes a power factor corrector, an auxiliary capacitor, a switching device, an auxiliary boost circuit, a controller and a voltage conversion device. The switching device has a first end electrically connected to the output end of the power factor corrector, and a second end electrically connected to one end of the auxiliary capacitor. An output end of the auxiliary boost circuit is electrically connected to the output end of the power factor corrector, an input end of the auxiliary boost circuit is electrically connected to a middle end of the switching device, and a ground end of the auxiliary boost circuit is electrically connected to another end of the auxiliary capacitor. The controller is electrically connected to the switching device and the auxiliary boost circuit. The input end of the voltage conversion device is electrically connected to the output end of the power factor corrector.

Abstract: A current source inverter includes a controller, an input unit, a buffer unit, a modulating unit, and a commutator. The controller generates a switch control signal, an inverse switch control signal, a first pulse width modulation control signal, and a second pulse width modulation control signal. The input unit stores and transmits input power of a direct current power supply according to the first pulse width modulation control signal. The buffer unit is coupled to the input unit for receiving and transmitting the input power. The modulating unit generates and outputs a full-wave rectified sinusoidal current according to the second pulse width modulation control signal and the input power. The commutator converts the full-wave rectified sinusoidal current into an alternating current according to the switch control signal and the inverse switch control signal and outputs the alternating current to a load or a utility line.

Abstract: A current source inverter includes a controller, an input unit, a buffer unit, a modulating unit, and a commutator. The controller generates a switch control signal, an inverse switch control signal, a first pulse width modulation control signal, and a second pulse width modulation control signal. The input unit stores and transmits input power of a direct current power supply according to the first pulse width modulation control signal. The buffer unit is coupled to the input unit for receiving and transmitting the input power. The modulating unit generates and outputs a full-wave rectified sinusoidal current according to the second pulse width modulation control signal and the input power. The commutator converts the full-wave rectified sinusoidal current into an alternating current according to the switch control signal and the inverse switch control signal and outputs the alternating current to a load or a utility line.

Abstract: An exemplary cooling fan includes a housing having an air inlet and an air outlet opposite to the air inlet, a rotor received in the housing, and a stator received in the housing and rotatably supporting the rotor. The rotor includes a hub, blades extending outwardly from an outer periphery of the hub, and flanges slantwise extending from top edges of end portions of the blades. In operation of the cooling fan, air located at an outside of the cooling fan enters the air inlet and flows towards the blades and along the flanges thereby pressing the rotor towards a bottom of the stator along an axial direction of the cooling fan, and the air subsequently flows out of the cooling fan via the air outlet.