Power supply apparatus and discharge method thereof
AssigneePower Forest Technology Corporation
InventorChia-Hsien Liu
Life of this patent
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Abstract
A power supply apparatus and a discharge method thereof are provided. A control unit detects a cross-voltage across two ends of an AC safety capacitor to generate a detection voltage, compares the detection voltage with a threshold voltage, counts the number of cycles of the detection voltage during a period when the detection voltage does not cross the threshold voltage according to a comparison result between the detection voltage and the threshold voltage, and performs a discharge operation when the number of cycles is greater than or equal to a predetermined value to discharge electric energy stored in the AC safety capacitor.
Claims12
A power supply apparatus, comprising:
- a power conversion circuit receiving an AC input voltage through an input side, and converting the AC input voltage into a DC output voltage;
- an AC safety capacitor connected across the input side;
- and
- a control unit coupled to the power conversion circuit and the AC safety capacitor, and controlling operation of the power conversion circuit, wherein the control unit detects a cross-voltage across two ends of the AC safety capacitor to generate a detection voltage, compares the detection voltage with a threshold voltage, counts the number of cycles of the detection voltage during a period when the detection voltage does not cross the threshold voltage according to a comparison result between the detection voltage and the threshold voltage when the detection voltage is still a sine wave, and performs a discharge operation when the number of cycles is greater than or equal to a predetermined value to discharge electric energy stored in the AC safety capacitor.
A discharge method of a power supply apparatus, wherein the power supply apparatus comprises a power conversion circuit and an AC safety capacitor, the power conversion circuit receives an AC input voltage through an input side, and converts the AC input voltage into a DC output voltage, the AC safety capacitor is connected across the input side of the power conversion circuit, and the discharge method comprises:
- detecting a cross-voltage across two ends of the AC safety capacitor to generate a detection voltage;
- comparing the detection voltage with a threshold voltage;
- counting the number of cycles of the detection voltage during a period when the detection voltage does not cross the threshold voltage according to a comparison result between the detection voltage and the threshold voltage when the detection voltage is still a sine wave;
- and
- performing a discharge operation when the number of cycles is greater than or equal to a predetermined value to discharge electric energy stored in the AC safety capacitor.
Dependencies are inferred from the claim text.