Abstract: The DC power supply apparatus includes a switching operation control part that is provided between a current detection part to detect a current flowing through a primary coil of a transformer and a control part to control the operation of a switching part and controls the operation of the switching part according to an output voltage so that consumption power in a low-load state can be further reduced.

Abstract: The transformer includes: first and second cores each including a magnetic center leg and a magnetic outer leg positioned outside of the magnetic center leg; a first adhesion part that adheres the magnetic center leg of the first core and the magnetic center leg of the second core to each other; a second adhesion part that adheres the magnetic outer leg of the first core and the magnetic outer leg of the second core to each other; a bobbin inserted through the magnetic center leg of the first core and the magnetic center leg of the second core, a primary coil and a secondary coil being wound on the bobbin; and an elastic member that applies pressure to the magnetic outer leg of the first core and the magnetic outer leg of the second core in a neighborhood of the second adhesion part, in an inward direction of the transformer.

Abstract: The power supply apparatus for obtaining a direct current from an alternating voltage source includes a first DC/DC converter for outputting a first direct current and a second DC/DC converter for a second direct current lower than the first direct current from the first DC/DC converter, and the output voltage of the first DC/DC converter is changed to a lower direct current and the second DC/DC converter is driven in a continuously-conducting state.