| 摘要 |
Electric heater assembly for use typically with hand-held soldering or desoldering devices includes an elongated resistance element formed from a thin flat metal foil having three connected areas of different resistance, the differing resistance being caused by the different widths of the areas. The first area, to which terminals are attached, is the widest and acts as a heat sink. The second area decreases in width to the first area and acts as a transition area between the first and third areas. The first and second areas include first and second separated portions for providing electrical current to the first area and returning it therefrom. The first area includes first and second strips respectively connected to the first and second portions of the second area. The strips extend adjacent a first side edge of the third area in a side-by-side relationship to the distal end of the resistance element and then back towards the second area to a position where they are connected to one another. The side-by-side position of the strips at the distal end of the third area facilitates application of heat to a work. An assembly for enclosing the resistance element to electrically isolate it from the work includes layers of insulating material between which the resistance element positioned and a sheet metal housing enclosure.
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