Power supply device for phase-shift resonance switch

The utility model relates to a phase-shift resonance type switch power supply device which is provided with a primary side position embedment diode and current-doubling rectification inductors (L1, L2). The parasitic oscillation of the auxiliary side of a transformer is avoided so that an absorber circuit of the diode is not required to be output. The circuit efficiency reaches the highest, and EMI is greatly reduced. Because L1 and L2 are connected with the secondary stage of the transformer in parallel, and the ZVS range at light load time is broadened, the circuits become still more practical and reliable, and the cost is still lower. Because the primary side realizes that peaks on a ZVS soft switch and an auxiliary side output diode are inhibited, favorable conditions are offered for component selection, fewer circuit components are used, and circuit structure is compact. Extremely high output efficiency can be obtained without any absorber circuit. Electromagnetic interference is small, which meets the EMC international standard.