Isamu Kobayashi , Kunihiko Mori , Naoyuki Chida , Atsushi Higashiura , Tadashi Ishii , Atsushi Taba
A triple-insulated winding wire with enhanced heat resistance, TEX-F, has been developed enabling further downsizing and performance upgrading of transformers for switching mode power supplies. In terms of thermal class, TEX-F belongs to the class F of 155°C, while conventional TEX-E belongs to the class E of 120°C. The available conductor sizes and insulation thickness are the same as for the conventional TEX-E, so that TEX-F winding wires with conductor sizes ranging from 0.2mm to 1.0mm covered with a thin triple-insulation layer of 100 µm (about 33 µm per layer) can be manufactured. As for safety standards, TEX-F meets IEC60950 like TEX-E, having acquired certification from a number of countries.
Moreover, unlike TEX-E, TEX-F is provided with the superior property in high-frequency V-t characteristics. This gives the wire substantial long-term resistance against corona discharge that is caused by excessive voltages on transformers, thus improving the reliability of transformers.