Y-free common-mode-free high-energy-efficiency power circuit

Abstract

The invention discloses a Y-free common-mode-free high-energy-efficiency power circuit which comprises an input rectification circuit, an EMI (electromagnetic interference) filter circuit, a voltage conversion circuit and a secondary rectification filter circuit. The Y-free common-mode-free high-energy-efficiency power circuit has the advantages that an auxiliary winding of a transformer comprisestwo layers of windings which are combined with one another, accordingly, interlayer capacitance can be reduced, and the Y-free common-mode-free high-energy-efficiency power circuit is greatly helpfulfor suppressing EMI; a magnetic core of the transformer is provided with a circle of self-adhesion copper coils along the line, and accordingly space radiation can be effectively suppressed; PCB (printed circuit boards) of the integral Y-free common-mode-free high-energy-efficiency power circuit are of double-sided board structures, radiation at PCB critical points can be suppressed by the aid ofcopper foil grounding modes, and the Y-free common-mode-free high-energy-efficiency power circuit is greatly helpful for suppressing the EMI; the Y-free common-mode-free high-energy-efficiency powercircuit with the structure is small and is simple in structure.

Description

technical field [0001] The invention relates to the technical field of power supply circuits, in particular to a high-energy-efficiency power supply circuit without Y capacitors and no common mode. Background technique [0002] At present, the demand for switching power supplies in the market continues to increase, and the power supplies provided by power supply suppliers are also different, resulting in increased competition in the power supply market. To gain a competitive advantage, products must have novel highlights. [0003] In existing circuits, Y capacitors are provided in EMI circuits of switching power supplies, but the presence of Y capacitors causes leakage current between input and output lines. Metal shells with Y capacitors will put users in danger of electric shock, so many places have started to use no-Y solutions, which will bring difficulties to EMI design and lead to low energy efficiency of power supply circuits. Contents of the invention [0004] Aim...

AI Technical Summary

Problems solved by technology

[0003] In the existing circuit, a Y capacitor is installed in the EMI circuit of the switching power supply, but the existence of the Y capacitor causes a leakage current between the input and output lines

The metal case with Y capacitors will put the user in danger of electric shock, so many places have started to use the Y-free solution, which will bring difficulties to EMI design and lead to low energy efficiency of the power supply circuit

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