| 摘要 |
Self-regulating electrical strip heaters which comprise at least two elongate conductors and at least one elongate resistive heating strip which contacts the conductors alternately as it progresses down the length of the heater. The conductors can be separated from each other by an insulating strip, with the heating strip being wrapped around the conductors and the insulating strip. Alternatively the conductors can be wrapped around a core comprising the heating strip and an insulating strip. The self-regulating characteistic of the heater preferably results from use of a PTC material, particularly a PTC conductive polymer in the heating strip. Preferably the junctions between the conductors and the heating strip are coated with a low resistivity conductive polymer composition.
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