150results about "Conversion using Cuk convertors" patented technology

A switching power converter tracks a time-varying input voltage during each cycle of the input voltage to provide power factor correction. The switching power converter includes a switch with a frequency and duty cycle modulated control signal. The switch controls the transfer of energy between the input and output of the switching power converter. The frequency of the control signal is greater than a frequency of the input signal. The control signal frequency is modulated during each cycle of the input voltage so that energy transferred from the switching power tracks the energy supplied to the switching power converter.

A new class of Three-Phase Isolated Rectifiers with Power Factor Correction provides a high efficiency, small size and low cost due to direct conversion from three-phase input voltage to output DC voltage.

A power supply comprises a pair of first and second capacitors forming a capacitive voltage divider. A source of a periodic input supply voltage is coupled to the capacitive voltage divider for producing in the second capacitor, from a portion of the periodic input supply voltage, a second supply voltage that is coupled to a load circuit. A switch is coupled to the second capacitor for selectively coupling the first capacitor to the second capacitor in a manner to regulate the second supply voltage.

A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node V_w to a node V_x. The node V_x is connected, in turn to ground by a power MOSFET. The node V_x is also connected to a node V_y by a first capacitor. The node V_y is connected to ground by a low-side inductor. A rectifier diode further connects the node V_y and a node V_out and an output capacitor is connected between the node V_out and ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node V_w. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value V_ref the comparator output causes the over-voltage protection MOSFET to disconnect the node V_w and the PWM control circuit from the input supply.

The invention discloses a wide-range bidirectional conversion circuit and a control method. The wide-range bidirectional conversion circuit comprises a three-stage bidirectional converter and a control unit, and the three-stage bidirectional converter is formed by sequentially connecting a non-isolated DC/DC converter, an isolated DC/DC converter and a DC/AC inverter. When the system works in theforward direction, a direct-current power supply or energy storage equipment realizes grid-connected energy feedback through the non-isolated DC/DC converter, the isolated DC/DC converter and the DC/AC inverter; and during reverse working, an alternating voltage supplies power to a direct-current load or charges an energy storage device through a rectifying circuit, the isolated DC/DC converter and the non-isolated DC/DC converter. In order to adapt to different power levels and realize higher input current ripple control, the non-isolated converter adopts a multi-phase interleaved parallel structure; and in order to further broaden the requirements of input and output ranges in practical application, the isolated converter can be controlled by adopting a full-bridge/half-bridge variable structure. The whole system has the advantages of wide input direct-current voltage range, wide output alternating-current voltage range, wide load range, small current ripple, high-frequency isolation, high efficiency, energy conservation, environmental protection and the like.

A power supply includes a supply inductor and a first capacitor coupled to form a resonant circuit to generate a resonant waveform in a resonant operation, during a first portion of an operation cycle of the power supply. A charge storage element develops an output voltage to energize a load. A rectifier is coupled to the charge storage element and to the resonant circuit and is responsive to the resonant waveform for applying the output voltage back to the resonant circuit to interrupt the resonant operation, at an end time of the operation cycle first portion, when the resonant waveform produces a first change of state in the rectifier. A first sensor senses when the first change of state in the rectifier occurs. A source of a supply current is coupled to the rectifier and rectified in the rectifier to produce a rectified current that is coupled to the charge storage element to replenish a charge therein, during a second portion of the operation cycle. A switching transistor is responsive to an output signal of the first sensor for enabling the supply current to be coupled to the rectifier, during the operation cycle second portion, and for disabling the supply current from being coupled to the rectifier, during the operation cycle first portion.

Disclosed is a low noise, non-isolated DC-DC converter for providing a non-inverted (i.e., the same polarity as an input voltage) output voltage of any desired voltage by stepping-up/down the input voltage. It comprises an input coil L1, an input capacitor C1 and a second intermediate coil Lm2 connected in series between both ends of the input voltage source, an output coil L2, an output capacitor C2 and a first intermediate coil Lm1 connected in series between both ends of a load Ro, a switching device S connected between a node a of the L1 and the C1 and a node b of the C2 and the Lm1, and a diode D connected between a node d of the C1 and the Lm2 and a node c of the C2 and the L2.

A method and an apparatus for transferring electric power to an electrical load (105); the method comprising steps of: converting a direct electric current into an electric tension wave, applying the electric tension wave in inlet to at least a couple of electric capacitors (125, 130); supplying the electrical load (105) with the electric tension in outlet from the capacitors (125, 130).

The present invention provides a power supply arrangement with a DC-to-DC converter (10) for providing at least one supply voltage to a load (20, 30, 40) from an energy source (11). The converter comprises means for inputting (4) a battery voltage from the energy source to output a voltage in a predetermined battery voltage range and a transfer circuit (8) connected to said means for inputting, to convert the battery voltage to at least one supply voltage in such a way that the supply voltage will be opposite in polarity to the battery voltage and the absolute value of the supply voltage will be the same or close to the absolute value of the battery voltage. The arrangement also comprises means for controlling (2), connected to the means for inputting, to control the supply voltage independent from the battery voltage using a single converting mode for the supply voltage range. The advantage of the arrangement is to supply continuously and ripple-free to the load the supply voltage range independent from but opposite in polarity to the battery voltage.

An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a power converter circuit that is electrically coupled to an electrical power source for receiving alternating current (AC) input power from the electrical source and delivering direct current (DC) output power to an electronic device. The power converter circuit includes a transformer and a switching device coupled to a primary side of the transformer for delivering power from the electrical power source to a primary side of the transformer. A controller is coupled to a voltage sensor and the switching device for receiving the sensed voltage level from the voltage sensor and transmitting a control signal to the switching device to adjust the voltage level of power being delivered to the electronic device.

The invention discloses an inverter for restraining the leakage current, wherein the inverter comprises a multi-level inverter bridge arm, a DC-DC converter, a first capacitor and a second capacitor.The positive input end and the negative input end of the DC-DC converter are respectively connected with the positive end and the negative end of a DC power supply. The positive input end and the negative input end of the inverter bridge arm are connected with the positive output end and the negative output end of the DC-DC converter respectively. The output end of the multi-level inverter bridgearm is connected with an AC power grid. The first capacitor and the second capacitor are connected in series and then are connected between the positive input end and the negative input end of the multi-level inverter bridge arm. The middle point of the multi-level inverter bridge arm is connected with a common point between the first capacitor and the second capacitor. The middle point of the multi-level inverter bridge arm is connected with the positive end or the negative end of the DC power supply. The N line of the AC power grid is connected with the middle point of the multi-level inverter bridge arm. Namely, the inverter for restraining the leakage current and provided by the invention is used for directly grounding the positive end or the negative end of the DC power supply. Therefore, the leakage current of the inverter is approximately zero.

The disclosure describes a charge device capable of charging electricity storage cells while eliminating a voltage variation among the electricity storage cells without a need for at least a circuit section playing a role in voltage equalization among the electricity storage cells to be designed to have a large current capacity, and describes a charge-discharge device constructed by additionally equipping a discharging function with the charge device. Provided are a charge device and a charge-discharge device each of which comprises a convertor, an input circuit, and a multi-stage voltage doubler rectifier circuit. An element in the convertor configured to be applied with a rectangular waveform voltage is connected to the multi-stage voltage doubler rectifier circuit via the input circuit to thereby realize a voltage equalization function, and an output section of the convertor is connected to the multi-stage voltage doubler rectifier circuit to thereby realize a charging-discharging function.

A DC-DC converter includes a power conversion portion including a switching element; a first resistor having one terminal electrically connected to the power conversion portion; a second resistor having one terminal electrically connected to the other terminal of the first resistor; a third resistor having one terminal electrically connected to the other terminal of the first resistor; a constant current supply electrically connected to the other terminal of the third resistor; and a control circuit electrically connected to the other terminal of the third resistor and configured to control the switching element. Resistance R₁ of the first resistor, resistance R₂ of the second resistor, resistance R₃ of the third resistor, a reference current I_ref output from the constant current supply, and an output voltage V_out output from the power conversion portion satisfy a following formula:

An integrated-type high step-up ratio DC-AC conversion circuit with an auxiliary step-up circuit applies to converting a low DC voltage of alternative energy into a high AC voltage. The conversion circuit uses an isolated Cuk integration unit and an auxiliary step-up unit to form a multi-phase input and uses parallel charging and cascade discharging to boost the DC voltage in the DC side with a low voltage power switches and low duty cycle and then converts the boosted DC voltage into AC voltage. The auxiliary step-up unit not only shares the entirety of power but also exempts the DC-side circuit from using high voltage power switches, whereby the cost of elements is reduced. Further, the conversion circuit can decrease the switching loss and conduction loss of the DC-side switches and promote the efficiency of the circuit.