Patent ID: 8063507
Filing Date: 2011-11-22
Classification: H02M

Abstract:
1. A multiple output switching power source apparatus, comprising: first and second transformers each at least having a primary winding, a first secondary winding, and a second secondary winding; a first control circuit configured to adjust a time for applying a DC voltage to the primary winding of the first transformer; a first rectifying-smoothing circuit configured to rectify and smooth a voltage induced at the first secondary winding of the first transformer and provide a first output voltage; a second control circuit configured to adjust a time for applying the DC voltage to the primary winding of the second transformer; a second rectifying-smoothing circuit configured to rectify and smooth a voltage induced at the first secondary winding of the second transformer and provide a second output voltage; a third rectifying-smoothing circuit configured to rectify and smooth a voltage across a winding circuit in which the second secondary winding of the first transformer and the second secondary winding of the second transformer are connected in series and provide a third output voltage; a first switching element to be turned on/off by the first control circuit; a second switching element to be turned on/off by the second control circuit; and a third control circuit configured to generate ON-timing control signals that change a time between the timing of turning on the first switching element and the timing of turning on the second switching element according to the third output voltage of the third rectifying-smoothing circuit, wherein the first and second control circuits turn on/off the switching elements at the same switching frequency according to the ON-timing control signals from the third control circuit.