A miniature transformer for use with printed circuit boards includes a winding assembly comprising a first tubular bobbin having a first winding thereon, and second and third tubular bobbins each having a winding thereon and being received, respectively, in the open opposite ends of the first bobbin. A shell member is received over the winding assembly and engages the ends of the second and third bobbins for holding the same within the first tubular bobbin. There are a pair of E-shaped core members each having a center leg received in the open ends of the second and third bobbins and side legs received in a gap between the shell member and the winding assembly.