Abstract: A quasi-resonant half-bridge converter includes a switch unit including first and second switches that are coupled in series, a capacitor unit coupled to the switch unit in parallel, a rectifier unit, an output capacitor, and a transformer coupled to the aforesaid components. The first and second switches are respectively controlled using first and second control signals that have a constant frequency. Duty cycles of the first and second control signals may be adjusted based upon a DC output voltage across the output capacitor for promoting conversion efficiency of the converter when operating at light load.

Abstract: A quasi-resonant half-bridge converter includes a switch unit including first and second switches that are coupled in series, a capacitor unit coupled to the switch unit in parallel, a rectifier unit, an output capacitor, and a transformer coupled to the aforesaid components. The first and second switches are respectively controlled using first and second control signals that have a constant frequency. Duty cycles of the first and second control signals may be adjusted based upon a DC output voltage across the output capacitor for promoting conversion efficiency of the converter when operating at light load.

Abstract: A core unit includes first and second core elements. The first core element includes a first peripheral portion and a first leakage inductance portion that is confined by the first peripheral portion and that has a first end surface. The second core element includes a second peripheral portion and a second leakage inductance portion that is confined by the second peripheral portion and that has a second end surface. The first and second peripheral portions are connected to each other, and the first and second end surfaces are disposed to face each other and are spaced apart from each other so as to form a gap therebetween. At least one of the first and second end surfaces is a non-level surface.