Dc-dc converter, dc-dc conversion method, and an information device

DC-DC converter, wherein by releasing the capacitor is charged for a specified period of time by the external voltage, an inductive element constituting the LC resonance circuit together with the capacitor, the stored energy of the capacitive element after the predetermined time period comprising a closed loop current path through which a current flowing through the LC resonance circuit oscillates, a transformer which receives the current flowing in the closed loop current path, and a rectifier circuit provided on the output side of the transformer.