摘要:
The present invention provides a heat sink device, suitable to the heat dissipation of a high-power medium-voltage drive power cell. The device comprises a heat dissipation substrate having a first surface, a second surface and an inner layer between the first surface and the second surface; a heat pipe having an evaporation section and a condensation section. The evaporation section is buried in the inner layer of the heat dissipation substrate, and the condensation section is used to dissipate the heat from the evaporation section to the air. The power elements of the high-power medium-voltage drive power cell are disposed on the first surface and the second surface, respectively.
摘要:
The present invention provides a power switch series circuit and its control method. The power switch series circuit includes a plurality of series modules, a control module and a drive module. At least one series module has a power switch and a detection module, and the detection module includes a detection unit and an isolation unit, so as to detect the overvoltage and output a voltage detection signal based on the detected voltage. The control module receives the voltage detection signal and outputs the corresponding control signal. The drive module amplifies the control signal to drive each power switch to turn ON or turn OFF. The control module outputs the corresponding control signal to turn off each power switch when the overvoltage happens.
摘要:
A DC/DC converter, a power converter and a control method thereof are disclosed, where the DC/DC converter includes an output circuit having a load, a rectangular wave generator having a bridge arm, a resonant tank, a detection unit and a control unit. The bridge arm includes a first and a second switches connected each other. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls ON/OFF state of the first and second switches by pulse width modulation mode to convert an input voltage into at least one rectangular wave for the resonant tank. A duty ratio of the first switch is within a first or second predetermined range, and a duty ratio of the second switch is complementary to the duty ratio of the first switch, whereby a voltage gain of the DC/DC converter is greater than 1.
摘要:
A resonance converter and a synchronous rectification driving method thereof are provided. The resonance converter includes a switch circuit having at least two first switches, a resonance circuit having a resonance frequency, a transformer, and a full-wave rectification circuit having two second switches each of which has a drain and a source and generates a channel resistance voltage when a current flows through the drain and the source. The synchronous rectification driving method includes steps as follow. When an operating frequency of the resonance converter is less than the resonance frequency and the resonance converter is coupled to a heavy load, the channel resistance voltage is compared with a reference voltage for driving the second switches of the full-wave rectification circuit; and when the operating frequency of the resonance converter is not smaller than the resonance frequency, duplicated signals of signals used to drive the first switches are respectively used to drive the second switches of the full-wave rectification circuit.
摘要:
A control method for reducing audio noise is disclosed. The method includes the steps of: providing an input power source; providing a power source converter having a component with a mechanical resonant frequency, coupled to the input terminal or the output terminal of the power source converter; providing an output capacitor and a load connected in parallel therebetween; making the power source converter operate in a burst mode; and controlling the electrical energy transferred from the input terminal to the output terminal of the power source converter during an operating period of every burst cycle, so as to reduce the audio noise of the power source converter.
摘要:
The DC/DC converter includes a power unit, an output detection unit, a control unit and a compensation unit. The output detection unit detects an output stage of the power unit. The control unit provides a driving signal based on the output stage for the power unit to control the operation of the power unit. When the power unit operates in an intermittent working mode, the compensation unit provides a compensation signal for the control unit, and the control unit adjusts the driving signal according to the compensation signal, so that during at least one duty cycle an output power of the power unit in the intermittent working mode is higher than an output power of the power unit at a switching moment from a normal mode (continuous working mode) to the intermittent working mode, thereby when the load is not changed, the average number of driving signals is reduced.
摘要:
A method of controlling an uninterruptible power supply apparatus (UPS) is provided. The UPS apparatus includes at least an AC input voltage, a DC input voltage and a single-phase AC/AC converter. The single-phase AC/AC converter includes an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm. The method includes steps of: controlling the bus voltage to have a DC component and full-wave rectifying component, and setting a bus voltage parameter K so that the bus voltage approaches to a full-wave rectifying voltage when K approaches to 1, wherein 0≦K≦1.
摘要:
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 α between the inclined surface and the radial plane is selected from a range of 90(1−1/(4P))
摘要:
A method and a device for controlling a discharge Lamp, and a discharge lamp system are disclosed herein. The method includes the operations of: when the lamp current changes, determining a percentage of change of the lamp current according to a synchronous signal and obtaining a second lamp current after a discharge lamp current changes according to the percentage of change of the lamp current and a first lamp current; obtaining a modulating signal according to a current difference between the first lamp current and the second lamp current; and generating a pulse voltage signal according to the modulating signal. The pulse voltage signal transits from a first voltage to a second voltage during the time period when the lamp current is transited from a first lamp current to a second lamp current during a transition time.
摘要:
An electronic ballast includes an inverter circuit, a variable inductor unit and a control circuit. The variable inductor unit is electrically coupled between the inverter circuit and an illumination device. The control circuit controls the variable inductor unit according to an operation mode of the inverter circuit such that an equivalent inductance of the variable inductor unit has a variation fed back to the inverter circuit, to further change the operation mode of the inverter circuit. An illumination apparatus and a method for protecting the electronic ballast are also disclosed.