Various embodiments of the teachings herein include a rectifier. The rectifier may include: a rectifier circuit formed with current valves with microelectromechanical systems (MEMS) switches; and a switching controller driving the MEMS switches to switch and open. The switching controller opens the MEMS switches when a voltage feeding the rectifier falls below a minimum distance from a zero voltage.

A display apparatus includes a body; a display provided in the body; a processor provided in the body and configured to control the display to display an image; and a power supply including an adapter configured to be detachable from the body, and a power assembly configured to receive power from the adapter in a non-contact manner and supply the power to at least one of the display and the processor.

A rectifier circuit has one or more bridge circuits each with: a first leg with two diodes in series and an AC terminal at a midpoint between the two, a second leg with two semiconductor switches in parallel to the first, a third diode connected to a upper node of each leg, a fourth diode connected to a lower node of each leg, and a capacitor leg with two capacitors in series between the third and fourth diode. A midpoint between the capacitors is connected to a midpoint between the semiconductor switches. The first arrangement is two controllable semiconductor switches in series. A gate node of the second is connected to a first load terminal of the first switch and the first load terminal is connected to the lower node. The second semiconductor switch is a third controllable semiconductor switch with a gate node connected to the lower node.

A device for providing power to a server rack includes a first AC input port, a second AC input port, a first relay, a second relay, and an output port. The output port is electrically connected to both the first AC input port and second AC input port. The first relay is electrically between the first AC input port and the output port, and the second relay is electrically between the second AC input port and the output port. The first relay and second relay are configured to compare a first phase of a first voltage from the first AC input port to a second phase of a second voltage from the second AC input.

Structures and functions of power supplies are disclosed. In an example, a power supply includes a power factor correction circuit and a bypass circuit. The bypass circuit bypasses the power factor correction circuit when the switch of the bypass circuit is on in response to a predetermined range of input power of the power supply. The bypass circuit also includes a delay circuit to delay the activation of the bypass circuits in response to the predetermined range of input power of the power supply for a predetermined time period.

A drive controller is used in a control system of a power factor correction (PFC) circuit. The control system further includes the PFC circuit. The PFC circuit includes a first bridge arm, a second bridge arm, a first switching transistor, and a second switching transistor. The driving controller includes a sampling circuit and a driving circuit. The sampling circuit is configured to obtain a target current value between the first switching transistor and the second switching transistor. The drive circuit is configured to turn off gate inputs of the first switching transistor and the second switching transistor when the target current value is greater than a current threshold, to turn off the first switching transistor and the second switching transistor and protect the control system.

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.

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.

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 power conversion device suppresses voltage variation of a power supply bus. The device includes a variation compensation circuit and a control circuit. The variation compensation circuit includes: a first capacitor connected to the power supply bus; a second capacitor connected in series between the first capacitor and a ground; an auxiliary capacitor; and a converter including a switching element and having a voltage step-down function, the converter being connected to the second capacitor and the auxiliary capacitor. The control circuit includes an active power calculating section that calculates instantaneous active power ip in the variation compensation circuit. The control circuit controls the voltage Vc of the auxiliary capacitor using the instantaneous active power ip.