A DC-to-DC converter includes a primary side of a transformer element of the DC-to-DC converter and a secondary side of the transformer element, the primary side having a first rectifier circuit and a primary-side resonant circuit and the secondary side having a second rectifier circuit and a secondary-side stored energy source, the transformer element being arranged between the primary side and the secondary side in order to transfer electrical energy, the secondary side having a secondary resonant circuit capacitor.