Abstract: An electrical heating cable with a first power supply conductor, a second power supply conductor, and a third power supply conductor. Each of the first, second and third power supply conductors extend along a length of the cable. The electrical heating cable also includes an electrically conductive heating element body, wherein the first, second and third power supply conductors are electrically coupled to each other via the electrically conductive heating element body. The second power supply conductor is provided with a layer of electrically insulating material which covers only a part of a surface of the second power supply conductor. The layer is provided between the surface of the second power supply conductor and the electrically conductive heating element body.

Abstract: An electrical heating cable with a first power supply conductor, a second power supply conductor, and a third power supply conductor. Each of the first, second and third power supply conductors extend along a length of the cable. The electrical heating cable also includes an electrically conductive heating element body, wherein the first, second and third power supply conductors are electrically coupled to each other via the electrically conductive heating element body. The second power supply conductor is provided with a layer of electrically insulating material which covers only a part of a surface of the second power supply conductor. The layer is provided between the surface of the second power supply conductor and the electrically conductive heating element body.

Abstract: According to a first aspect of the present invention, there is provided a self-regulating electrical heating cable comprising: a first power supply conductor extending along the length of the cable; a second power supply conductor extending along the length of the cable; a third power supply conductor extending along the length of the cable; the first and second power supply conductors being in electrical connection with each other via a first electrically conductive heating element body having a positive temperature coefficient of resistance, and the second and third power supply conductors being in electrical connection with each other via a second electrically conductive heating element body having a positive temperature coefficient of resistance, and wherein, in use, the first, second and third power supply conductors are not physically connected to one another.

Abstract: An electrical device includes a compound material. The compound material includes a mixture of an electrically conductive material and an electrically insulative material. The conductive material is aligned within the compound material, such that the resistivity of the compound material in a first direction is different from the resistivity of the compound material in a second direction perpendicular to the first direction.

Abstract: A material comprises: a first component having a first positive temperature coefficient of resistance characteristic; and a second component having a second positive temperature coefficient of resistance characteristic, the second positive temperature coefficient of resistance characteristic being different from the first positive temperature coefficient of resistance characteristic, the proportions of the two components being such that the material has a positive temperature coefficient of resistance characteristic which is a combination of the first and second positive temperature coefficient of resistance characteristics of the first and second components.

Abstract: According to a first aspect of the present invention, there is provided a self-regulating electrical heating cable comprising: a first power supply conductor extending along the length of the cable; a second power supply conductor extending along the length of the cable; a third power supply conductor extending along the length of the cable; the first and second power supply conductors being in electrical connection with each other via a first electrically conductive heating element body having a positive temperature coefficient of resistance, and the second and third power supply conductors being in electrical connection with each other via a second electrically conductive heating element body having a positive temperature coefficient of resistance, and wherein, in use, the first, second and third power supply conductors are not physically connected to one another.

Abstract: Devices and methods for the control of heating cables are described. A first heating cable assembly includes a heating cable, a heater regulator for connection electrically in series between the heating cable and a voltage source. The heater regulator comprises a material having a positive temperature coefficient of resistance such that in use the voltage across the heating cable is dependent upon the temperature of the heater regulator. A second heating cable assembly includes a heating cable having a resistive heating element, a material having a positive temperature coefficient resistance for controlling the heat output from the heating cable, and a cold start limiter element comprising a material having a negative temperature coefficient of resistance for connection electrically in series with the heating element and a voltage source.

Abstract: An electrical device includes a compound material. The compound material includes a mixture of an electrically conductive material and an electrically insulative material. The conductive material is aligned within the compound material, such that the resistivity of the compound material in a first direction is different from the resistivity of the compound material in a second direction perpendicular to the first direction.

Abstract: An electrical heating cable of the type in which two power supply conductors extend along the length of the cable and the heating element extends along the length of the cable and between the two conductors, connected in parallel between the conductors. One or both of the conductors is encased in the sheath of material which has a positive temperature coefficient and the heating element is in electrical contact with the outer surface of the sheath. As a result the sheath is electrically connected in series between each heating element and the conductor encased by the sheath. The sheath may be manufactured from a material which provides a very rapid rise in electrical resistance at a predetermined temperature, thereby enabling the manufacture of a cable which delivers substantially constant power below the predetermined temperature with a rapid reduction in power output at the predetermined temperature.

Abstract: A self-limiting electrical heater comprising an elongate resistance heating element and a PTC resistor. The resistor is elongate and extends side-by-side with and along the length of the heating element so as to be responsive to the temperature of the entire length of the heating element. The heating element and resistor are connected in series, the resistor having a positive temperature coefficient such that its electrical resistance is substantially less than that of the heating element when at a normal operating temperature but increases rapidly when exposed to temperatures above the normal operating temperature.

Abstract: A heating tape is described which comprises two longitudinally extending foil conductors and a longitudinally extending tape incorporating heating elements spaced apart along its length. The heating elements are connected electrically in parallel between the heating foils, enabling the heating tape to be powered from one end.