Switching Power-Supply Device

摘要

A switching power-supply device includes: a first series circuit including a first switching element; and a second switching element, a second series circuit including a third switching element and a fourth switching element; and a control unit that, while making frequencies of switching signals of the first series circuit and the second series circuit be the same, performs control of turning on-and-off the first switching element and the second switching element, alternately, with dead time at which the first switching element and the second switching element become off and turning on-and-off the third switching element and the fourth switching element, alternately, with dead time at which the third switching element and the fourth switching element become off, wherein the control unit controls a phase difference between the switching signal of the first series circuit and the switching signal of the second series circuit.

主权项

1. A switching power-supply device comprising:
a transformer having a primary coil and a secondary coil that is magnetically coupled with the primary coil; a first series circuit including a first switching element and a second switching element, the first series circuit being connected to both ends of a direct-current power supply; a series resonance circuit including a capacitor connected to one end of the second switching element and the primary coil connected between the capacitor and the other end of the second switching element; a second series circuit including a third switching element and a fourth switching element, the second series circuit being connected to both ends of the direct-current power supply; a reactor that is connected between a connection point of the third switching element and the fourth switching element and a terminal of the capacitor connected to the primary coil; a rectification-and-smoothing circuit that is connected to the secondary coil, and a control unit that, while making frequencies of switching signals of the first series circuit and the second series circuit be the same, performs control of: turning on-and-off the first switching element and the second switching element, alternately, with dead time at which the first switching element and the second switching element become off; and turning on-and-off the third switching element and the fourth switching element, alternately, with dead time at which the third switching element and the fourth switching element become off, wherein the control unit controls a phase difference between the switching signal of the first series circuit and the switching signal of the second series circuit.