Flex Ltd.

HuaMin Xu

WeiAn Chen

Xiao Liu

Steven Shen

Liu Xiao Dong

Vifor Wang

Weijia Yan

Chen Wei An

Baoming Mei

A rectifier includes a first input and a second input that receive an unrectified signal, a first circuit portion including a first transistor coupled to the second input, a second circuit portion including a second transistor coupled to the first input, a third circuit portion including a third transistor coupled to the first input, a fourth circuit portion including a fourth transistor coupled to the second input. The first, second, third, and fourth circuit portions are operable to convert the unrectified signal into a rectified signal. The rectifier includes a first adjustment circuit coupled to a gate of the third transistor, and a second adjustment circuit coupled to a gate of the fourth transistor. The first adjustment circuit and the second adjustment circuit are configured to control a dead time between an on-state of the third transistor and an on-state of the fourth transistor.

Devices, systems, and methods for power supplies

An input redundant power supply circuit includes a power converter, a relay switch unit including a first relay circuit coupled to a first power source and a second relay circuit coupled to a second power source, a control unit configured to control the relay switch unit so that the power converter is supplied power by the first or second power source, a high capacity capacitor powered by the power converter and a step-up converter coupled between the power converter and the high capacity capacitor. The step-up converter maintains a voltage across the high capacity capacitor higher than a voltage of the first power source or a voltage of the second power source when the relay switch unit switches from one of the first power source and the second power source to the other of the first power source and the second power source.

Input redundant power supply with zero current switching

At least one example embodiment is directed to a method for controlling a rectifier. The method includes applying a first control signal to a first switch of the rectifier to cause a first current to flow through a first inductor of the rectifier, applying a second control signal to a second switch of the rectifier to cause a second current to flow through a second inductor. The second control signal and the first control signal have a phase difference. The method includes detecting that the first current falls to a first minimum value at a first time, detecting that the second current falls to a second minimum value at a second time, determining a first difference between the first time and the second time, and determining whether to adjust the second control signal based on the first difference to bring the phase difference closer to a target phase difference.

A power converter with AFC (Automatic AC Feed Control) implements zero voltage switching when switching from a first input power supply to a second input power supply. The power converter with AFC includes a relay switchover circuit and control circuitry for selectively providing power to a connected power converter. The control circuitry uses sensed amplitude and phase values for the two input power supplies for determining when the first input power supply is lost and selectively connecting the second input power supply according to precise timing control to minimize component stress.

Automatic AC feed control (AFC) with zero voltage/current switching

A power supply has a first stage for performing AC-DC voltage conversion and power factor correction and a second stage for isolated DC-DC voltage conversion. The power supply includes a feed forward mechanism for transmitting phase information corresponding to AC ripple. The phase information is transmitted from the first stage to a secondary side of the second stage as a digital signal using a low speed optical coupler, where the phase information is utilized by a DC-DC digital controller to implement AC ripple suppression using both phase compensation and amplitude compensation.

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Shenzhen, China

HuaMin Xu