Single-stage alternating-current/direct-current conversion device

The invention relates to a single-stage alternating-current/direct-current conversion device comprising an energy storage unit, a magnetic unit, a switch unit, an iron core, a first winding, a second winding, a third winding and at least one output winding, wherein the magnetic unit is electrically connected with the energy storage unit and the switch unit; the first winding is coupled with the iron core and derives a first electric energy to the iron core; the second winding is coupled with the iron core and stores a second electric energy to the energy storage unit; the third winding is coupled with the iron core and derives the second electric energy to the iron core; the output winding is coupled with the iron core; and the iron core converts the first electric energy and the second electric energy and outputs a third electric energy by coupling with the output winding.