261results about How to "Wide input voltage range" patented technology

An AC-to-DC power converter configured to provide power factor correction and a single isolated low-voltage output. The power converter includes a single-stage resonant power converter including an isolation transformer, a resonant tank, a rectifier, and a bulk storage capacitor coupled to an output of the isolation transformer. In typical applications, at least one non-isolated power converter is coupled to the output of the single-stage isolated power factor correction converter.

A voltage acquisition circuit for sensing input voltage signals in each phase of an electrical service includes a non-active current transformer configuration that is operable over a wide input voltage range. The current transformer configuration includes primary and secondary windings, an input resistor and a burden resistor across which an output voltage is defined. The input resistor may be relatively large, such as on the order of about one MΩ and the transformer core may have a nanocrystalline core characterized by predictable magnetic properties versus varied transformer flux levels. This operational predictability facilitates phase compensation via digital filtering or otherwise for any phase shift induced between input and output voltages of the current transformer. The subject voltage acquisition circuits may be provided to sense each phase of a single-phase or polyphase electrical service, whereby the sensed voltages are subsequently provided to additional components of an electricity meter, such as a power supply or other processing components, including an A/D converter and microprocessor for determining energy quantities.

A cascaded H bridge multilevel converter and a control method thereof are provided. The converter includes two passive DC buses and a conversion circuit of which the three phases are of the same structure. The conversion circuit includes n cascaded inverter modules of the same structure. Each inverter module includes a photovoltaic sub module and an H bridge unit. Each photovoltaic sub module is a three-port interleaved parallel Boost LLC DC converter. Of the two input ports on the primary side of each photovoltaic sub module, one input port is connected with the output end of a solar photovoltaic power generation module, and the other input port is connected across the two DC buses. The output port of each photovoltaic sub module is connected with the input port of the corresponding H bridge unit. In each phase of conversion circuit, the output ports of the n H bridge units are cascaded to form an output port of the phase of conversion circuit. Photovoltaic module maximum power point tracking and LLC DC converter output voltage control are realized by controlling the duty ratio and switching frequency of a switching tube. Therefore, the problem that the intra-phase and inter-phase output power of the cascaded H bridge converters in a large-scale photovoltaic grid-connected power generation system is imbalanced is solved.

The invention relates to an electric energy feedback type electronic load. The input end of the electronic load employs a large-current single-channel access mode. A main circuit mainly comprises a DC/DC conversion circuit, a DC/AC inverter circuit, and an AC filter output circuit, wherein the DC/DC conversion circuit employs a phase-shifted full-bridge circuit to achieve the control of DC input, and boosts DC input voltage. In order to adapt to large-current input, a switching device is formed by parallel connection of a plurality of MOSFETs. The DC/DC conversion circuit is connected with the DC/AC inverter circuit through a DC bus. The DC/AC inverter circuit employs a single-phase full-bridge inverter circuit to control AC output current so as to stabilize the voltage of the DC bus and feeds the AC current back to a power network by a unit power factor. The DC/AC inverter circuit employs an IGBT module as a power device. The AC filter circuit can employ an LC low-pass filter circuit so as to eliminate the higher harmonic waves in the output current of the DC/AC inverter circuit and improve the quality of grid-connected electric energy.

A control circuit for a common line is provided. The control circuit is connected to each of common lines of a liquid crystal display. The control circuit modulates the voltage of each individual common line. The control circuit controls the switching time of the common line according to a pass pulse, and switches the voltage of the common line according to two switching signals. The two switching signals have opposite logic levels in the same frame time.

A lamp oscillator which outputs a sawtooth wave signal to be compared with an error signal of an output voltage in order to generate a PWM signal. The oscillator includes a first charging current changing circuit, in which a current amplifier converts a differential voltage between the error signal and a reference voltage into a current and outputs the converted current. When the load of a switching power supply circuit is heavy, a capacitor is charged with a constant current and generates a sawtooth wave signal having a predetermined slope. During a light load, the first charging current changing circuit adds the current, which increases as the load becomes lighter, to the current to thereby make the slope of the sawtooth wave signal steeper.

The invention discloses a dual-Sepic buck-boost output parallel combined inverter, which comprises two buck-boost Speic DC/DC circuits that are connected in parallel at the output side, and which can realize the buck-boost single-phase inversion and expand the buck-boost single-phase inversion in a three-phase system to realize the three-phase inversion output. The inverter has the basic function of realizing buck-boost inversion; when the direct-current voltage at the input side is lower or the change range is larger, the dual-Sepic buck-boost output parallel combined inverter still can realize the inversion function; two high-frequency switching tubes adopt a non-complementary work manner and do not work simultaneously, therefore, the bridge through problem is prevented; the circuit parameter designing principle can be designed according to the mature direct-current Sepic converter designing principle; the inductive current works under the continuous state and reduces the influence of the EMI (Electro-Magnetic interference). The invention is mainly applied to the field of renewable energy source or new energy source generation with lower direct-current voltage, faster change or larger fluctuation range, such as photovoltaic power generation, a small Wind turbine generator system, fuel cell generation, and the like.

A start-up circuit includes a switching-device control circuit arranged to receive an input voltage and to provide a switching-device control signal, a switching device arranged to be controlled by the switching-device control signal and to provide a start-up signal, a power-converter control circuit arranged to receive the start-up signal and to provide a power-converter control signal, and a power converter arranged to receive the power-converter control signal and to provide an auxiliary output signal. The switching control circuit is arranged to receive the auxiliary output signal such that, when the auxiliary output signal reaches a predetermined level, the switching-device control circuit stops providing the switching-device control signal.

The configurations of an isolated DC/DC converter and an isolated DC/AC converter and the controlling methods thereof are provided. The proposed isolated DC/DC converter includes a DC/AC switching device, a transformer, a rectifier, and a duty ratio and frequency modulating apparatus coupled to the rectifier and the DC/AC switching device for generating a driving signal to adjust a duty ratio and a frequency of the switching device so as to regulate an output DC voltage of the converter.

The invention discloses a light-emitting diode (LED) driver for illumination. The LED driver for the illumination comprises an alternating current (AC)/direct current (DC) module and a constant current control module, wherein the AC/DC module adopts an LLC resonant conversion topological structure, and is used for converting alternating current commercial power into direct current; and the constant current control module is connected with the AC/DC module and used for outputting constant current by taking low-voltage direct current as driving voltage to drive an LED light source by the constant current. The LED driver for the illumination can realize the constant current driving of LEDs for the illumination, and simultaneously ensures the safety and reliability of the LEDs.

The peak current flowing to the switching device drops in a no-load state with PWM control, but because the number of switching operations is constant regardless of the load, further reducing power consumption is difficult. The switching power supply device has a PWM signal generator for generating a PWM signal, a switching device Q1 for switching the first supply voltage VIN based on the PWM signal, converters for outputting the difference between a second supply voltage and a reference voltage as a difference signal, and an intermittent oscillation control circuit for stopping the switching operation of the first switching device when the difference signal is less than a predetermined first threshold value (Vp1). The PWM signal generator changes the pulse width based on the difference signal to generate the PWM signal.

The invention discloses a multi-path input alternating/direct current (AC/DC) hybrid power supply. The output end of a main power supply is connected with a rectifying bridge; the output end of each spare power supply is respectively connected with a rectifying bridge; the output ends of all the rectifying bridges are connected in parallel, wherein the positive output ends of the rectifying bridge are connected with the input end of a live line of an AC/DC power converter; and the negative output ends of the rectifying bridge are connected with the input end of a zero line of the AC/DC power converter. The power supply has the advantages of needing no additional switcher to control the switching of the main power supply and the spare power supply, realizing the power supply with high cost performance, reducing conversion time, realizing uninterrupted power supply, strengthening the reliability of the power supply, realizing hot spare function and leading the main power supply and the spare power supply to have dual effects; a mode with a plurality of rectifying bridges is adopted to expand the input voltage range; the input voltage can be alternating current with different frequencies and different phases, or one alternating current, one direct current, and even the two are direct current input.

This invention puts forward a dual-feedback short-circuit protection device including a current test circuit, a second signal comparison circuit and a short-circuit operating circuit connected orderly characterizing in also including a compensated signal delay circuit, a first signal comparison circuit and the short-circuit operating circuit connectd orderly, in which, the compensated signal delay circuit delays the voltage compensation signal and outputs it to the first signal comparison circuit, which compares the input signal with a threshold value, if it is greater than that, it sends a short-circuit control signal to the operation circuit to control the switch entering into a short-circuit protection state, when the supply with a capacitance load operates normally, the delay circuit outputs a threshold value with the voltage smaller than the first signal comparison circuit, the short-circuit operation circuit does not operate, when the load is over a preset sphere, it outputs a threshold value with the voltage greater than the first one, the operation circuit controls the switch supply entering into a short-circuit protection state.

A power supply circuit, comprising a first reverse blocking transistor coupled to an AC power line; a second reverse blocking transistor coupled to the AC power line; a first inductor provided between the first reverse blocking transistor and the AC power line and configured to store energy; a first diode having a first terminal that is coupled to one end of the first inductor; a first capacitor having a terminal that is coupled to a second terminal of the first diode; and a first output terminal provided between the first diode and the first capacitor. The first and second transistors are arranged in an anti-parallel configuration and together define an AC switch.

The invention relates to the design field of a switch power supply, in particular to a high position energy-taking power supply device of a submodule of an MMC valve and a realizing method thereof. The high position energy-taking power supply device supplies power to a controller, a driver and a protective device of the submodule of the MMC valve. The device is characterized in that the device comprises a main circuit, electromagnetic interference circuits respectively arranged at input and output ends of the main circuit, and a fault output circuit arranged at the output end of the main circuit. The fault output end of the fault output circuit is connected with the controller of the submodule through optical fiber. The device provided by the invention has the characteristics of wide input voltage range, high isolation voltage and high reliability. Through serial input of a multi-flyback circuit, the input voltage stress is reduced, the reliability of the circuit is improved, and the electromagnetic compatibility (EMC) characteristic of the power supply is improved. Two-level isolation makes circuit outputs separated from each other, and the output short-circuit does not affect input.