Acbel Polytech Inc.

Cheng-Hsiao Luo

Wei-Liang Lin

I-Hsiu Lo

Chia-An Yeh

Bing-Kun Lai

A current sampling circuit for a bridgeless power factor corrector is provided. The current sampling circuit comprises a sampling resistor, a first and second current sampling modules. In the first and second current sampling modules, primary windings of transformers are respectively serially connected to a first and second fast switches of the bridgeless power factor corrector. In a positive half cycle of the AC power, a second sampled current phase switching unit is turned on to form a second sampling circuit, and a first main current freewheeling unit is turned on to form a freewheeling path of a first transformer. In a negative half cycle of the AC power, a first sampled current phase switching unit is turned on to form a first sampling circuit, and a second main current freewheeling unit is turned on to form a freewheeling path of a second transformer.

Current sampling circuit for bridgeless power factor corrector

A power supply having ORing MOSFETs mounts a voltage regulating unit between a main power module and an auxiliary power module of a secondary side of the power supply. The voltage regulating unit regulates a control voltage received by a driving unit, such that a voltage difference between a gate voltage and a source voltage of one of the ORing MOSFETs can be less than a rated voltage threshold for avoiding damaging the one ORing MOSFET.

Power supply having ORing MOSFETs

A totem-pole PFC and a current-sampling unit of the totem-pole PFC are provided. The totem-pole PFC is electrically connected to an AC power source and a DC-to-DC converter, and is electrically connected to a load through the DC-to-DC converter. The current-sampling unit has a first sampling switch and a second sampling switch. The first sampling switch and the second sampling switch are controlled to be turned on and turned off so that a magnetizing current flows through the magnetizing inductor when a magnetizing inductor is magnetized and a demagnetizing current does not flow through the sampling resistor when the magnetizing inductor is demagnetized, thereby increasing the demagnetization efficiency and overcoming superimposed operations to improve current detection and increase conversion efficiency of the power conversion.

Totem-pole power factor corrector and current-sampling unit thereof

A feed forward controlling circuit is used to perform a feed forward controlling method to restrain ripple of the output voltage in a power converter. The power converter is controlled by a control signal outputted from an output terminal of a controller. The method includes steps of: receiving an output voltage from an output terminal of a voltage converter; attenuating the output voltage to generate an electrical signal; acquiring a DC signal from the electrical signal; and obtaining a ripple compensation signal in accordance with the electrical signal and the DC signal to output to an output terminal of a controller. The output terminal of the controller outputs a control signal to control the power converter.

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Taipei, Taiwan

Cheng-Hsiao Luo