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AssigneeAstec International Limited
InventorsWeng Fai NG, Wai Chung LI, Kwok Wai LO, Zhi Zhi LI, Chun Shing CHENG, Ka Kit LI
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A control circuit is configured to sense an AC input voltage of a power factor correction (PFC) power circuit in a switching power converter, provide a control signal having an on-time and an off-time to at least one power switch of the PFC power circuit, and in response to detecting a peak voltage of the AC input voltage, increase the on-time of the control signal based on the sensed AC input voltage during an interval that begins with the peak voltage of the AC input voltage and ends with the next zero crossing following the peak voltage of the AC input voltage to improve a power factor of the switching power converter. Other example switching power converters, PFC power circuits and control circuits for controlling one or more power switches are also disclosed.
A switching power converter comprising:
A control circuit for controlling at least one power switch in a PFC power circuit of a switching power converter, the PFC power circuit controllable to improve a power factor of the switching power converter, the control circuit configured to sense an AC input voltage of the PFC power circuit, provide a control signal having an on-time and an off-time to the at least one power switch of the PFC power circuit, and in response to detecting a peak voltage of the AC input voltage, increase the on-time of the control signal based on the sensed AC input voltage during an interval that begins with the peak voltage of the AC input voltage and ends with the next zero crossing following the peak voltage of the AC input voltage to improve the power factor of the switching power converter.
Dependencies are inferred from the claim text.