초록 ▼

An electrical heater which comprises a fabric prepared from at least one of the electrodes and another elongate element of substantially higher resistance. The heater preferably comprises a PTC element, e.g. of a conductive polymer, to render the heater self-regulating. The PTC element may be in the

An electrical heater which comprises a fabric prepared from at least one of the electrodes and another elongate element of substantially higher resistance. The heater preferably comprises a PTC element, e.g. of a conductive polymer, to render the heater self-regulating. The PTC element may be in the form of a fiber forming part of the fabric, or a layer surrounding one of the electrodes, or a laminar element in which the fabric is embedded. The fabric can if desired be laminated to a sheet of a polymer, e.g. an insulating polymer or a ZTC conductive polymer. A shrinkable fabric heater can be made by incorporating a heat-shrinkable non-conductive filament into the fabric, perpendicular to both electrodes, and is useful for example for enclosing splices in telephone cables.

대표청구항 ▼

An electrical heater which comprises a fabric comprising elongate elements which are interlaced together in an ordered array and at least some of which comprise a component composed of material having a resistivity greater than 10-5 ohm.cm, said heater comprising (1) a first elongate electrode which

An electrical heater which comprises a fabric comprising elongate elements which are interlaced together in an ordered array and at least some of which comprise a component composed of material having a resistivity greater than 10-5 ohm.cm, said heater comprising (1) a first elongate electrode which forms at least part of one of said interlaced elements; (2) a second elongate electrode which forms at least part of one of said interlaced elements; (3) a PTC element which is in the form of a layer electrically surrounding the first electrode and which (a) exhibits PTC behavior, and (b) is composed of a conductive polymer which comprises a polymeric component and particulate conductive polymer dispersed in the polymeric component; and (4) a substantially continuous laminar element which is composed of a ZTC conductive polymer and through which current passes when the electrodes are connected to a source of electrical power.