Abstract: A conductive winding electrically isolated by reflowable material which is incorporated into a transformer further including individual layers of electrical insulation material. The transformer is formed in a layered configuration wherein isolation requirements set forth by safety certification agencies are met through the use of the reflowable material and insulation layers.

Abstract: A method for making a coil assembly of the telescoping bobbin type wherein axially spaced coils are wound on an elongate tubular form comprising two spool-like bobbin sections integrally joined to each other in end-to-end relation by thin rupturable webs. The core of one bobbin section has an opening therethrough sized to receive the flanges of the other bobbin section. After winding of the coils is completed, the bobbin sections are axially pressed toward each other to rupture the rupturable webs and telescope one bobbin section into an opening of the other.