The most simple circuit type DC DC converter with isolation transformer is characterized in that the core of the high-frequency transformer is excited by the unidirectional pulsating current, and the magnetic flux in the core changes only on the hysteresis loop in one cycle, so the magnetic properties of the core Can you make full use of it? According to the excitation direction in a week, there are forward and flyback converters. There are also Cuk converters with isolation. There can be multiple outputs.