Patent ID: 7221111
Filing Date: 2007-05-22
Classification: H02M,H05B,Y10S

Abstract:
1. A switching power supply device comprising: a power converter; a first smoothing capacitor coupled to the power converter; a DC-DC converter including a converter transformer with a primary coil and a secondary coil, the primary coil being coupled to the power converter and the first smoothing capacitor; a second smoothing capacitor coupled to the secondary coil of the DC-DC converter; a synchronizing rectifier circuit coupled to the secondary coil of the DC-DC converter; an alternating current driver circuit; and control means for coordinating start time points of current conducting periods between (i) an output of the power converter and an input to the DC-DC converter to coincide with each other and (ii) an output of the DC-DC converter and an input of the alternating current driver circuit to coincide with each other.