Dc-dc converter

A DC-DC converter comprising:

• a first full-bridge circuit including four switching elements that include a capacitor serving as a parasitic capacitance or an external parallel-connected capacitor;
• a second full-bridge circuit including four switching elements that include a capacitor serving as a parasitic capacitance or an external parallel-connected capacitor;
• a transformer including a first winding and a second winding, the first winding being connected to said first full-bridge circuit, and the second winding being connected to said second full-bridge circuit and magnetically coupled to said first winding;
• an inductance component connected in series with said first winding or said second winding;
• and
• a control circuit that controls soft switching of each switching element in said first full-bridge circuit and said second full-bridge circuit,
• wherein said control circuit is capable of executing an output angle modulation mode or a phase control mode and executes said output angle modulation mode or said phase control mode depending on target power desired to be output, the output angle modulation mode being a mode of adjusting a voltage output period of said first full-bridge circuit and a voltage output period of said second full-bridge circuit, and the phase control mode being a mode of changing a phase of a voltage on said first winding and a phase of a voltage on said second winding.