초록 ▼

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,

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.

대표청구항 ▼

A self-regulating strip heater which comprises (1) first and second elongate, spaced-apart, conductors which can be connected to a source of electrical power and (2) an elongate resistive heating strip which (i) comprises an elongate PTC component which (a) runs the length of the heating strip and (

A self-regulating strip heater which comprises (1) first and second elongate, spaced-apart, conductors which can be connected to a source of electrical power and (2) an elongate resistive heating strip which (i) comprises an elongate PTC component which (a) runs the length of the heating strip and (b) is composed of a conductive polymer composition which exhibits PTC behavior, and (ii) is in electrical contact alternately with the first conductor and the second conductor at contact points which are longitudinally spaced apart along the length of the strip and along the length of each of the conductors.