| 摘要 |
PURPOSE:To protect effectively from transient overvoltage of surge voltage and the like by a method wherein a nonlinear resistance element is connected between a neck section of a cooling duct and a member with potential. CONSTITUTION:A low voltage winding 4 and a high voltage winding 5, which are lapped to a metallic sheet 2 and an insulating sheet 3 at the leg section of a core, are wound and a hollow state cooling duct 6 is self-contained inside the winding 4 and 5. The cooling duct 6 is connected to a liquid-guide pipe 9 through an insulative pipe 8 from the neck section 7 of the said duct. The plural nonlinear resistance elements 12 is connected in the state of lamination among the neck section 7, the liquid-guide pipe 9, whick comes to be earth potential, such as a core cramping 10 and a tank 11. As the cooling duct 6 is the same electric potential as an adjointed winding, the nonlinear resistance element 12 functions most effectively and so can suppress sufficiently transient over-voltage such as surge voltage which invades from outside. |
