Abstract: A conductive polymeric tape has elongate electrodes, (6) extending along its long edges, and comprises a central longitudinal strip (8) of different resistance to the remainder of the tape. The strip (8) extends part way only along the tape. The tape may also, or instead, contain discontinuities (20) preferably extending across the tape. The purpose of the strip (8) and the discontinuities (20) is to control the passage of electrical current and also the heat output of different parts of the tape.

Abstract: An office interface unit (OIU) transfers data and signaling between a telephone local exchange and distribution lines. Information from the telephone local exchange is contained in repetitive frames containing signaling time slots which each contain two distinct nibbles of information. The OIU translates each local exchange signaling channel into first and second internal signaling channels, each internal signaling channel containing information representative of one signaling nibble therein. This simplifies DSO time slot interchange in the OIU. In addition, each internal signaling channel is provided with at least one additional significant signaling bit thereby providing additional signaling states so that the OIU equipment can account for multiple types of telephone local exchange equipment easily.

Abstract: A mass termination connector (2) having a low profile backshell which may be efficiently stacked. A wiring assembly (24) having conductors (26) extend through a braid (10) and a backshell adapter body (6) to a connector housing (4). The braid is attached to the exterior of the adapter body, removed from the interior compartment, to protect the wiring assembly from chafing during shock and vibration.

Abstract: An arrangement for enclosing the termination of a screened electrical cable to an electrical conductor comprises a coupling element, e.g. an adaptor (1) that is intended to engage the connector and is formed from a metal having a conductive passivate layer thereon, and a dimensionally recoverable article (2) for enclosing the termination after recovery onto the cable. The article (2) includes an electrical screen (8) and is partially recovered into engagement with the coupling element (1) so that an end of the screen (8) is in electrical contract with a portion (5) of the coupling element. The portion (5) of the coupling element has no passivate layer thereon.It has been found that the electrical resistance of the band formed between the screen (8) and the coupling element (1) is relatively constant during storage at elevated temperature.

Abstract: A color projection display uses a dichroic cube for modulating the color of light reaching the imaging element of the display. This way, a colored image may be projected by frame sequential technique, but with the use of only a single imaging element.

Abstract: A wraparound heat shrinkable sheet for covering pipes or cables is positioned therearound so its longitudinal edges overlap. A first patch is then positioned over the lapped edges, and a second patch, which is wider than the first patch, positioned over the first patch and secured to the underlying wrapped sheet. Heat is then applied, preferably by hot mastic. The heat acts to shrink the sheet which tensions the second patch, thereby directing a radial force downward onto the first patch.

Abstract: A device 1 for forming an electrical connection between a plurality of electrical conductors comprises an electrically insulating sleeve (3), a metallic connecting element (4) located within the sleeve and a quantity of solder (8) for forming a permanent electrical connection between the conductors. The connecting element (4) has an external surface that is uneven so that a significant proportion of any radiation that is radially inwardly directed onto the external surface of the element will be reflected at least twice by the external surface of the element.This uneveness enables the response of the device to heating by infrared radiation to be significantly improved. The connecting element may be formed for example by coiling a wire having a polygonal, e.g. square, cross-section into a frusto-conical helix.

Abstract: An assembly capable of enclosing and sealing an intermediate section of an optical fiber includes a plurality of sealing mechanisms arranged such that the assembly can be entered to gain access to electronic components for servicing without affecting an environment occupied by optical fiber broken out of an optical fiber cable. Accordingly, physical integrity of the exposed fiber, and its associated connectors and splices, is not compromised. The assembly further includes a plurality of card cages, each of which has its own integral backplane having socket connectors which allow for connection to an adjacent card cage backplane within the assembly. During initial deployment of the assembly where less than all card cages for maximum capacity are initially required to be deployed, segmenting the backplane reduces the first installed cost of the assembly.

Abstract: Telomers of the structure ##STR1## are disclosed, where R is --CH.sub.3 or H; R' is a C.sub.5 to C.sub.18 alkyl or fluoroalkyl group; n is an integer between 2 and 6 inclusive; and x is an integer between 3 and 26 inclusive. These telomers are surface active and are useful as aids for coating applications.

Abstract: An electrical insulator comprising a cylindrical core (2) of an insulating refractory material, such as porcelain, onto a portion of the curved surface of which a sleeve (8) of insulating polymeric material is fitted. Metal end-caps (4), for electrically connecting the insulator, are fitted to the ends of the porcelain core such that there is an exposed portion (10) of the curved surface of the core between the sleeve and each end-cap. Thus, any damaging electrical activity which takes place at the metal end-caps is directed primarily onto the surface of the porcelain core (2), and not onto the surface of the electrically vulnerable polymeric sleeve (8), which serves to protect mechanically the relatively brittle porcelain core. Optionally, the polymeric sleeve (8) may have a convoluted or a shedded outer surface (12) to increase the leakage path length of the insulator, or to prevent the formation of a continuous moisture path, or both.

Abstract: A heating device for recovering a heat-recoverable plastics sleeve about a portion of a wire harness comprises a housing having a heating location when the portion of the harness and heat-recoverable sleeve are introduced, and a heating unit that is movable between a rearward position in which it surrounds the heating location. The heating unit comprises a pair of heating jaws (5,5') that open as they move toward the heating location and then close as they arrive at it so that the portion of the harness to be heated is completely enclosed within the heating unit. The jaws open again when they recede from the heating location to allow the harness to be removed.

Abstract: A conductive polymer composition in which a particulate conductive filler is dispsered in a polymeric component which is a mixture of an essentially amorphous thermoplastic resin and a thermosetting resin. In preferred compositions, the amorphous thermoplastic resin and the thermosetting resin are substantially mutually soluble. In order to improve the thermal stability of the composition on exposure to successive thermal cycles, it is preferred that the composition be cured by heating the uncured mixture of amorphous thermoplastic resin, thermosetting resin, and particulate conductive filler at a rate of at least 15.degree. C./minute to the cure temperature.

Abstract: Detection of liquid leaks and other changes in variables is disclosed. The event causes two elongate conductors to become electrically connected at a location which is determined by the event, thus creating a system in which the connection point can be located by measuring the potential drop from one end of one of the conductors (called the locating member) to the connection point. The system comprises a balancing component so that its sensitivity is not dependent on the location of the event along an elongate path. A fixed current flows through the connection, so that the result is independent of the resistance of the connection. The locating member can be a continuous resistive wire, coated with a conductive polymer; such a locating member can form part of a sensor cable in which the elongate components of the circuit are in a wrapped configuration. Alternatively the locating member comprises a plurality of discrete resistors.

Abstract: Electrically conductive polymers, especially polypyrroles, are formed with a charged polymeric dopant supplying the necessary counter-ions to stabilise the charged conductive form of the conductive polymer. The physical properties of the conductive polymer can thus be usefully modified in ways different from those achieved by non-polymeric dopants or by forming the conductive polymers in pre-existing bodies of non dopant (i.e. uncharged) polymers.

Abstract: A system for employing induction heating to heat a non-magnetic, electrically non-conductive material in situ quickly, uniformly, selectively and in a controlled fashion. Particles which are essential to the improved use of induction heating for this type of application are added to the host material and exposed to high frequency alternating electromagnetic fields such as those produced in an induction coil. The particles are ferromagnetic, having high magnetic permeability and high electrical conductivity. The heat-generating efficiency of these particles when exposed to alternating magnetic fields, permits a smaller volume fraction of these particles in the host material such that the desired properties of the article remain essentially unchanged. Overheating of the article may be prevented by selecting the particle Curie point such that the particle autoregulates at a temperature about equal to the temperature to which the article is to be heated.

Abstract: A device (1) for forming an electrical connection at the end of a bundle of wires (2) comprises an electrically insulating, preferably heat-shrinkable, sleeve (3), a metallic connecting element (4) located within the sleeve, and a quantity of solder (8) for forming a permanent electrical connection between the conductors. The connecting element (4) has a tapering internal surface which has a screw thread so that a temporary electrical connection can be formed by screwing the bundle of wires into the connecting element. Preferably the connecting element is formed by winding a wire, e.g. hard tempered copper wire, into a frusto-conical form. Splices in wire bundles may be made by means of a device in which the connecting element has a pair of internally threaded portions into which different cable bundles can be screwed.

Abstract: A projector having a light valve which operates by alternatively transmitting incident light or scattering such light has adjustable illumination and projection apertures to maximize contrast ratio and brightness according to ambient light conditions.

Abstract: A conductive polymer composition which has low resistivity and good electrical stability. In one aspect the composition comprises a nonconductive filler which is a dehydrated metal oxide. In another aspect the composition comprises a conductive filler which is metal particles in which the bulk density is less than 0.15 times the true density. Compositions of the invention are particularly useful for circuit protection devices.