Disclosed herein is a charger capable of bidirectional power transfer. A power factor compensation circuit converts a multi-phase AC voltage into a DC voltage and includes a plurality of inductors and a plurality of switching elements. The DC voltage converted by the power factor compensation circuit is applied to a DC link capacitor. A bidirectional DC converter bidirectionally converts the magnitude of a voltage between the DC link capacitor and a battery. In DC power supply mode, a controller controls the bidirectional DC converter to convert a magnitude of a voltage of the battery to apply the voltage of the battery to the DC link capacitor and controls the plurality of switching elements to generate a DC supply voltage by converting the magnitude of the DC voltage of the DC link capacitor and output the DC supply voltage through a terminal through which the multi-phase AC voltage is input.

An embodiment charging device includes a power factor correction circuit first to third switch legs connected to first to third inductors, respectively, a relay network for controlling connection between the first to third inductors and first to third input terminals according to a phase of a power grid connected to the first to third input terminals, a relay control circuit connected to the first to third input terminals for sensing one of the first to third input terminals to which a power source is connected and controlling the relay network based on a sensing result, and a relay filter circuit including first to third filter capacitors connected between a ground plane and first to third sensing lines connected to the relay control circuit for sensing voltages of the first to third input terminals and a fourth filter capacitor connected between the ground plane and a chassis.

A dual-input power conversion system includes a first primary side power network coupled between a first ac power source and a first primary winding of a transformer, a second primary side power network coupled between a second ac power source and a second primary winding the transformer, a secondary side power network coupled to a secondary side of the transformer, and a power converter coupled between the secondary side power network and a load.

An embodiment apparatus for an electric vehicle includes an indoor power outlet configured to receive power through one of a plurality of lines except for a single-phase alternating current (AC) charging line among three-phase AC input lines, a sensor configured to measure a required current of an electronic device connected to the indoor power outlet, and a controller configured to control a bidirectional on board charger of the electric vehicle based on the required current.

There is provided a high frequency AC inverter comprising a DC-DC circuit, an output power circuit and a load circuit and a controller, the load circuit comprising a load circuit detector configured to detect the electrical parameters of the load circuit. The output power circuit comprises a DC to AC driver having a variable frequency output, a HFAC driver circuit comprising a resonant network and a transformer coupled to the HFAC driver circuit and the load circuit. The controller is configured to control the output frequency of the DC to AC driver and the output of the DC to DC circuit in response to the detected electrical parameters of the load circuit.

There is provided a high frequency AC inverter comprising a DC-DC circuit, an output power circuit and a load circuit and a controller, the load circuit comprising a load circuit detector configured to detect the electrical parameters of the load circuit. The output power circuit comprises a DC to AC driver having a variable frequency output, a HFAC driver circuit comprising a resonant network and a transformer coupled to the HFAC driver circuit and the load circuit. The controller is configured to control the output frequency of the DC to AC driver and the output of the DC to DC circuit in response to the detected electrical parameters of the load circuit.

A system for an AC to DC PFC converter includes a first phase switch group connected to a first node to receive power from a first phase of a voltage source; a second phase switch group connected to a second node to receive power from a second phase of the voltage source; a third phase switch group connected to a third node to receive power from a third phase of the voltage source; a neutral phase switch group connected to a fourth node to be connected to a ground terminal of the voltage source; a first switch connected to the first node and the second node; and a second switch connected to the second node and the third node.

An electronic apparatus includes: an operator; and a power circuit configured to supply power to the operator, wherein the power circuit includes a first voltage converter configured to output a first voltage based on input power, and a power factor corrector (PFC) configured to output a second voltage by performing power factor correction for the first voltage, and supplies power based on the first voltage or the second voltage to the operator, wherein the power circuit stops an operation of the PFC, lowers the first voltage to have a level corresponding to the second voltage, and supplies power based on the lowered first voltage to the operator, based on power consumption of the operator lower than or equal to a predetermined value.

An electronic apparatus includes: an operator; and a power circuit configured to supply power to the operator, wherein the power circuit includes a first voltage converter configured to output a first voltage based on input power, and a power factor corrector (PFC) configured to output a second voltage by performing power factor correction for the first voltage, and supplies power based on the first voltage or the second voltage to the operator, wherein the power circuit stops an operation of the PFC, lowers the first voltage to have a level corresponding to the second voltage, and supplies power based on the lowered first voltage to the operator, based on power consumption of the operator lower than or equal to a predetermined value.

A communication device for connection with a power source and a host device is provided. The communication device comprises a device controller and a converter circuit. The device controller is adapted for data communication with the host device and the converter circuit is configured to provide a virtual device ground at least to the device controller, so as to compensate a ground potential difference between the host device and the communication device.