Abstract: A resistor apparatus for containing broken pieces of an overheated resistor body is provided. The resistor apparatus includes a resistor body and a first and second lead wire electrically connected to opposite sides of the core. A gas permeable containment casing substantially encloses the resistor body and is fixed to the lead wires by fasteners, therefore maintaining the containment casing in a position substantially enclosing the resistor body. In the event that the resistor overheats and the resistor body breaks, the containment casing is maintained in a position to contain any pieces of the overheated resistor that break away, while allowing any gasses to escape, therefore preventing explosion of the containment casing and damage to surrounding apparatuses.

Abstract: A connection endpiece placed on a resistor element provided with at least one layer of electrically-conductive fibers, the endpiece serving to connect a power supply wire electrically to the resistor element. The endpiece includes at least one metal plate having a top face for connection to the power supply wire, and provided with at least one rigid metal connector member of substantially flat shape arranged at a first end of the metal plate and connected to at least one layer of electrically-conductive fibers of the resistor element, the top face of the metal plate being covered in a removable anti-adhesive covering.

Abstract: A coaxial heating cable comprising a central electrically conductive heating core is formed from a conductor having a resistance with a positive temperature coefficient of at least 30% at 20.degree. C. An electrically insulating polytetrafluoroethylene sheath surrounds the core, and an outer electrically conductive ground shield encloses the sheath. The ground shield comprises a number of contiguous strands which are helically wound in a single layer around the sheath. The cable preferably has a maximum diameter of 1 mm and the conductive core conveniently has a resistivity of between 0.4 ohmsm.sup.-1 and 2 ohmsm.sup.-1. The heating cable may be used in under-carpet heating. The invention extends to a method of forming a coaxial heating cable.

Abstract: A sensor array, usually a sensor matrix for sensing pressure, comprising a grid of conductors in a woven fabric, the row conductors crossing over the column conductors to form a matrix array of crossover points. The rows are separated from the columns by individually coating the conductors of one or both series with an electrically partially resistive fibrous material, so that when the conductors at any crossover point in the array are pressed closer together, the resistance between the two conductors at that crossover point decreases. By connecting the conductors to suitable electrical circuitry, the force applied at any crossover point and the location of that crossover point within the array can be determined.

Abstract: An improved electric resistance heating element made of a carbon material, provided around its surface with a layer essentially comprising carbon fiber, and an improved electric resistance heating furnace using the heating element.

Abstract: The device includes a coiled conductor formed of an alloy having a high electrical resistance and has an outer tubular casing of plastic material which is inert to acid or alkaline solutions. A flexible sleeve braided of fibrous glass material is slidably assembled on the coiled wire and the sleeve with coiled wire within is inserted as a subassembly into the outer tubular member to form an assembly for immersion in the liquid to be heated. Opposite ends of the heating cable extend above the liquid for attachment to electrical connections from a source of electrical power. Ground wires may also be provided to permit running of the electrical energy to ground in the event the outer tubular member is ruptured in service. Support rods are usually provided to anchor the cable to the desired configuration when immersed in the liquid to be heated.