Patent ID: 7872560

Claim:
A magnetic device, comprising: one or more pairs of up-and-down symmetrical ER-type or RM-type soft ferrite magnetic cores; at least one printed circuit board capable of forming different numbers of inductor winding turns, said printed circuit board constituting a primary winding of a planar transformer; at least two planar copper plates or two printed circuit boards to constitute two respective secondary windings of said planar transformer; and a plurality of output terminals for electrically connecting said primary winding of said planar transformer with said secondary windings of said planar transformer, wherein said magnetic device and a main circuit board are electrically connected by said output terminals, wherein different winding output connection structures can be formed by upward disposing a component side or a solder side of one piece of said at least one printed circuit board that constitutes said primary winding, wherein when two pieces of said at least one printed circuit boards that have the same number of inductor winding turns are stacked in sequence to constitute two primary windings by upwardly disposing their respective component sides, said magnetic device and said main circuit board can be electrically connected via said output terminals, and said two primary windings can be connected to each other in parallel by means of terminals on said magnetic device directly.