Winding assembly and magnetic assembly

A magnetic assembly, comprising:

• a first winding assembly and a magnetic core, the first winding assembly being assembled with the magnetic core;
• wherein the first winding assembly comprises a first coil and a first circuit board, the first coil is embedded inside the first circuit board, and the first coil comprises a conductive wire with at least one turn, and a height of the conductive wire in a direction perpendicular to the first circuit board is not less than a width of the conductive wire in a direction parallel to the first circuit board,
• wherein the first circuit board further comprises at least one flat copper coil disposed on a surface of the first circuit board or embedded inside the first circuit board, and the at least one flat copper coil is insulated with the first coil, wherein the flat copper coil and the first coil are wound around an identical single magnetic column of the magnetic core, and neither coil is wound around any other magnetic column, and wherein an orthographic projection of the at least one flat copper coil in a plane where the first circuit board is located partially overlaps with an orthographic projection of the first coil in that plane.