Patent ID: 8107263
Filing Date: 2012-01-31
Classification: H02M,Y02B

Abstract:
1. A series resonant converter circuit, comprising: an inverter circuit that is connected between a pair of DC input terminals to which DC input voltage is applied and has at least a first switching element and a second switching element that are alternately turned on and off; a transformer having a primary winding wire connected to the inverter circuit and a secondary winding wire; a resonant inductance means that is connected in series to the primary winding wire or the secondary winding wire of the transformer; a primary-side resonant capacitor that is connected in series to the resonant inductance means and the primary-side winding wire of the transformer when the first switching element or the second switching element turns on; and a multi-functional rectification circuit that is includes a first secondary-side resonant capacitor and a second secondary-side resonant capacitor that are connected to each other in series between a pair of DC output terminals, and a first unidirectional element and a second unidirectional element that are connected to each other in series between the DC output terminals, wherein a connection point of the first secondary-side resonant capacitor and the second secondary-side resonant capacitor is connected to one end of the secondary winding wire of the transformer, when a load connected between the DC output terminals is high impedance, the multi-functional rectification circuit functions as a voltage doubler rectification circuit and the resonant inductance means cooperates with the primary-side resonant capacitor, the first secondary-side resonant capacitor, and the second secondary-side resonant capacitor to resonate in series, when a load connected between the DC output terminals is low impedance, the multi-functional rectification circuit mainly functions as a full-wave rectification circuit and the resonant inductance means mainly cooperates with the primary-side resonant capacitor to resonate in series, and current flowing in the switching element is modified so as to be close to a sinusoidal waveform in a broad load impedance.