A circuit includes two input nodes and two output nodes. A rectifier bridge is coupled to the input and output nodes. The rectifier bridge includes a first and second thyristors and a third thyristor coupled in series with a resistor in series. The series coupled third thyristor and resistor are coupled in parallel with one of the first and second thyristors. The first and second thyristors are controlled off, with the third thyristor controlled on, during start up with resistor functioning as an in in-rush current limiter circuit. In normal rectifying operation mode, the first and second thyristors are controlled on, with the third thyristor controlled off.

A switching power supply device according to an embodiment of the present disclosure includes: power supply circuits corresponding to phases of a polyphase AC power supply as an external power supply; a switching circuit configured to switch a connection destination of another power supply circuit other than a specific power supply circuit corresponding to a specific phase of the external power supply among the power supply circuits to a phase corresponding to the other power supply circuit or the specific phase; and a control unit configured to connect, to each phase of the external power supply connected to the switching power supply device, the other power supply circuit corresponding to the phase, and connect the other power supply circuit as a surplus to the specific phase when the number of phases of the external power supply is smaller than the number of the power supply circuits.

According to one aspect, a power device is provided. The power device includes an input having at least a first connection and a second connection, and configured to be coupled to an AC power source to receive input AC power, a converter circuit coupled to the input and configured to convert an input AC voltage to a DC voltage, a load output configured to provide output power derived from the DC voltage, a rectifier circuit coupled to the input and having a first output and a second output, and a first capacitor coupled to the first output of the rectifier circuit and the second output of the rectifier circuit.

According to one aspect of the present disclosure, a method is provided including acts of receiving input Alternating Current (AC) power, providing the input AC power to at least one diode bridge to generate Direct Current (DC) power, providing, by the at least one diode bridge, the DC power to at least one set of diodes, providing, by the at least one set of diodes, the DC power to at least one output reactor, and providing, by the at least one output reactor, the DC power to an output.

An LED filament bulb includes a driver and two filament sets. The driver includes a rectifier circuit, a filter circuit, a constant voltage (CV) circuit, a first constant current (CC) circuit and a second CC circuit. The rectifier circuit converts an AC power into a DC power. The filter circuit connects the rectifier circuit for filtering an AC component. The CV circuit connects the filter circuit for generating a fixed voltage and outputting the fixed voltage via a voltage output end. The voltage output end connects a first electrode of each filament set. The first CC circuit connects both the CV circuit and a second electrode of one of the filament sets. The second CC circuit connects both the CV circuit and a second electrode of another one of the filament sets. The CC circuits make currents flowing through the two filament sets identical.

An electronic device according to the present invention includes a power supply unit and a load, the power supply unit including a ground terminal, a rectifier circuit, a circuit section connected to a DC output of the rectifier circuit, the circuit section supplying electric power to the load, a first varistor connected at one end thereof to one input end of the rectifier circuit, a second varistor connected at one end thereof to another input end of the rectifier circuit and connected at another end thereof to another end of the first varistor and an arrester connected at one end thereof to the another end of the second varistor and connected at another end thereof to the ground terminal, wherein an electrostatic capacity of each of the first and second varistors is 40% or more of a sum of earth capacitances of the power supply unit and the load.

A fault switch configuration and clearing method in a flexible DC converter station, the flexible DC converter station is configured with a grid side switch and a valve side phase-split switch in the converter station. When a fault occurs, a faulty phase and a non-faulty phase are detected and identified by means of differential protection or low voltage overcurrent. An alternating current zero crossing condition is created by means of firstly turn off the non-faulty phase valve side phase-split switch and the grid side switch, thereby cutting off the faulty phase, disconnecting the connection between a power supply and a fault point, and achieving the clearing for faults. The described fault-clearing method is simple and practical, highly reliable, and connection between the fault point and the power supply is quickly and effectively cut; converter station equipment is effectively protected, and further expansion of the fault is avoided.

A power train is described herein comprising a load, a first power supply for providing power to the load, a DC-link capacitor connected to the load, a main converter configured to convert DC power to AC power for powering the load; and pre-charge circuitry. The pre-charge circuitry comprises pre-charge means configured to, during a first, pre-charge phase, prevent said power from being provided to said load but provide power to said DC-link capacitor to charge said DC-link capacitor, and, further configured to, during a second, post-charge phase, allow said power to be provided from said first power supply to said load. A method for providing power to the load is also described herein.

An AC-DC converter circuit can include a plurality of passive components configured to convert AC to DC and to non-linearly regulate output DC voltage to about a selected maximum throughout an AC input voltage range and/or generator frequency. The plurality of passive components can be configured to also limit power loss as a function of load on a DC side.

The present disclosure relates to a conversion circuit, an inverter, and a method of driving the inverter, wherein a switch is provided at an input terminal of a direct current (DC) link capacitor, so that power is charged in the DC link capacitor through a switching element at initial driving and charged in the DC link capacitor through a rectifier when a voltage level of the DC link capacitor is equal to or higher than a preset reference level, thereby limiting inrush current caused in the DC link capacitor through the switching element when the inrush current is caused.