摘要 |
The invention provides an electrical device having improved insulation and reduced partial discharge. The electrical device comprises an electrically conductive resistive element provided on a heat transfer medium for transferring heat from the element. The heat transfer medium includes a layer or body of electrically conductive material and a layer of thermally conductive dielectric material disposed between the element and the electrically conductive material. A continuous film of electrically insulating material, for example a silica over-glaze or polymer encapsulant, is applied around the perimeter of the resistive element to surround the element with the film overlying the edge or edges of the element and the ceramic material adjacent thereto.
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