Patent ID: 8284009

Claim:
A transformer comprising: a first bobbin including a first winding portion around which a primary coil is wound; a second bobbin disposed adjacent to the first bobbin and including a second winding portion around which a secondary coil is wound; and a core made of a magnetic material, disposed across the first bobbin and the second bobbin, and forming a closed magnetic path, wherein the core is divided into a first core positioned on the side where the first bobbin is present and a second core positioned on the side where the second bobbin is present, and wherein the transformer further comprises an insulating member including (i) an outer circumference sheath and (ii) a first barrier interposed in a magnetically coupled portion between the first core and the second core, wherein the outer circumference sheath covers the outer circumference of at least one of the first core and the second core, wherein the first barrier is interposed between the opposing surfaces of the first core and the second core, wherein the first bobbin and the second bobbin are disposed adjacent to each other in the axial direction thereof, wherein each of the first core and the second core includes (i) a pair of outer cores extending in the axial direction along the outer sides of the corresponding one of the first bobbin and the second bobbin and (ii) an inner core positioned in between the outer cores and inserted into the corresponding one of the first winding portion and the second winding portion, wherein the insulating member is interposed between each of the first outer cores and the corresponding one of the second outer cores, wherein the transformer further comprises a second barrier formed between the first winding portion and the second winding portion, the second barrier being interposed between the opposing surfaces of the inner cores, wherein the transformer further comprises an insulating sheath formed at an end of one of the first winding portion and the second winding portion, the insulating sheath covering the outer circumference of the primary coil or the secondary coil that is not associated with the one of the first winding portion and the second winding portion, and wherein the insulating member is formed integrally with the outer circumference of the insulating sheath.