Abstract: Semiconductor devices and multiply-accumulate operation devices are disclosed. In one example, a semiconductor device includes synapses in which a nonvolatile variable resistance element taking a first resistance value and a second resistance value lower than the first resistance value and a fixed resistance element having a resistance value higher than the second resistance value are connected in series. An output line outputs a sum of currents flowing through the plurality of synapses.

Abstract: An exhaust gas heating arrangement includes a heating unit having a jacketed heating element having a jacket and at least one heating conductor which extends in the jacket and is surrounded by insulating material. The heating unit is spirally wound surrounding a longitudinal center axis (L), wherein a radially inner winding end region of the heating unit is offset with respect to a radially outer winding end region of the heating unit in the direction towards the longitudinal center axis (L).

Abstract: A heated whip hose includes a hose core configured to deliver a fluid, a heating element disposed around the hose core, a protective layer disposed around the heating element and hose core, an insulating layer disposed around the protective layer, and an abrasion protection layer disposed around insulating layer and forming an outer sheath.

Abstract: A coil device for a motor vehicle has a housing which has a receiving area, at least one secondary coil which is arranged in the receiving area for inductively transmitting electric energy in order to charge an energy storage unit of the motor vehicle, and at least one ferrite element which is arranged in the housing for conducting at least one magnetic field in order to inductively transmit the electric energy. The ferrite element has at least two ferrite regions that are at least partly mutually spaced by at least one through-opening which is arranged between the ferrite regions and in which a support structure is at least partly arranged that is made of a fiber composite material and has ferrite elements received in the fiber composite material, wherein opposing housing elements of the housing are supported against each other via said support structure.

Abstract: A cable is composed of a cable core including one or more electric wires, a braided shield covering a periphery of the cable core and including braided metal wires, a sheath covering a periphery of the braided shield, and a cushion layer provided between the cable core and the braided shield. The cushion layer is composed of a braid including braided linear shape fiber yarns.

Abstract: A wire for an ignition coil assembly and/or a corona ignition assembly is provided. The wire comprises a wire core including a copper-based material, and a coating applied to the wire core. The coating includes at least one of a carbon-based material and magnetic nanoparticles. The carbon-based material can include graphene and/or carbon nanotubes, and the magnetic nanoparticles can include graphene and iron oxide (Fe3O4). Typically, the coating includes a plurality of layers. For example, the coating can include a layer of the graphene and/or carbon nanotubes, and/or a layer of the magnetic nanoparticles. The coating can also include a layer of insulating material, such as enamel. According to another embodiment, the coating includes iron, nickel, and/or cobalt plated onto the wire core.

Abstract: A thermal tag for activity monitoring. The thermal tag includes a base layer having a plurality of metal lines to provide a conductive path, and a pattern layer having one or more infrared emitting features positioned over portions of the conductive path, wherein at least one infrared emitting feature couples to the conductive path to emit a predetermined infrared pattern in accordance with nearby activity.

Abstract: The invention relates to an apparatus for carrying a cable, wherein the cable comprises a conductor, a shield braid surrounding the conductor, a protective coat; the protective coat is removed along a part of its length, so that the shield braid is exposed; a housing surrounding the cable; an electrical connection in order to establish a conductive connection between the shield braid and the housing; a hinged sleeve is provided, which encloses the cable in the longitudinal section of the exposed shield braid; the hinged sleeve consists of an electrically conductive material which is connected to the housing in a conductive manner.

Abstract: A method of protecting retail store inventory from theft includes the steps of providing an electrical alarm circuit which is electrically connectable to a security loop cable. The security loop cable includes a plurality of electrically conductive and connectable security loop cable segments. A user forms the security loop cable by connecting the plurality of security loop cable segments end-to-end and attaches the security loop cable to the items of inventory. The free ends of the security loop cable are physically secured, including at least one of the free ends being physically secured by electrically connecting it to the electrical alarm circuit. The physical securement of the free ends prevents detachment of the inventory items from the cable. The alarm system when armed will activate an alarm if electrical continuity of the security loop cable is broken.

Abstract: Laser-markable cable layers for a cable are provided. The laser-markable cable layers include an inner layer formed of a first polymer material and an outer layer formed of a second polymer material and a laser-marking compound. The outer layer is about 0.5% to about 50% of the thickness of the inner layer. The laser-markable cable layers surround a wire or cable core. Methods of marking a cable having laser-markable cable layers are also provided.

Abstract: A detectable tracer element for use in underground detection applications includes a metallic wire, a non-fibrous insulating jacket integral with the wire, and a flexible, cut-resistant, non-electrically shielding woven protective tube surrounding the wire and jacket combination. The woven protective tube includes a plurality of non-metallic fibers woven around the wire and jacket combination such that the combination is disposed within the interior of the protective tube. In one configuration of the invention, the woven protective tube defines a substantially oval or circular tube weave. The substantially oval or circular tube weave is woven, such that, the tube weave is pulled or stitched into a flattened configuration for use in underground applications.

Abstract: A conductive element suitable for the transmission of an electrical operating signal to a detonator, which conductive element comprises a conductive filler homogeneously dispersed in a polymer matrix.

Abstract: An electric line comprising: at least one conducting substrate including at least two heating fields of different width, at least one shared contacting device, wherein the conducting substrate includes a coating material disclosed on the conducting substrate that forms the at least two heating fields, and the same coating material is disposed on the at least two heating fields, and wherein an electrical conductivity of the coating material on one of the at least two heating fields is different than a second one of the at least two heating fields of different width so that upon application of the coating material on the at least two heating fields, each of the at least two heating fields have an identical electrical resistance, and wherein the at least one shared contacting device connects the at least two heating fields to an electrical potential by one or more connection lines.

Abstract: A system for measuring electrical properties of a power line comprising a first wire and a second wire. The system comprises a sensor unit configured for connection to the first wire; and an elongated resistive element comprising a first end configured for connection to the sensor unit and a second end configured for connection to the second wire, the elongated resistive element having a distributed resistance. The first wire may be a hot wire and the second wire may be a hot wire or a neutral wire.

Abstract: The method and system of high-resistance, multiple-conductor flat cables which contain integral tunable resistance sections suitable for fine tuning the resistance of a conductor to match the resistance of the conductors to one another within a specified target value. The method involves the design and creation of the high-resistance, multiple-conductor flat cables and the tuning of the resistance of the conductor.

Abstract: A power amplifier (power amplifier) having multiple solid state sub-amplifiers connected in parallel between the power amplifier input and the power amplifier output are described. The signal input to the power amplifier is provided to an RF splitter connected between the power amplifier input connector and the input of each of the sub-amplifiers. The RF splitter splits the input power from the signal input and provides the power to the sub-amplifier inputs through input electrical paths. The input electrical paths from the power amplifier input to the sub-amplifiers are substantially physically identical. Each of the sub-amplifiers drive an input of an RF combiner connected between the outputs of the sub-amplifiers and the output of the power amplifier. The RF combiner combines the output power from each of the sub-amplifiers through output electrical paths, and provides the combined power to the power amplifier output.

Abstract: A method ignites the combustion of fuel in a combustion chamber (5) of engine (2), by introducing microwave radiation into the combustion chamber (5). The microwave radiation is produced in a microwave source (7) on the outside of the combustion chamber (5). The introduced microwave radiation is absorbed by the fuel distributed in the combustion chamber (5). The supply of energy, in the fuel, arising from absorption, distributes combustion in a large-volume in the combustion chamber (5), preferably in the entire combustion chamber (5) and in a homogenous manner, and is essentially simultaneously ignited. An associated ignition device (1) and an associated engine (2) are also provided.

Abstract: Disclosed is a device for the remote operation of the variable audio controls of floor-mounted audio effects devices, such devices typical of those used by performing artists on stage. The vast majority of devices of this type are operated by a foot pedal-controlled on/off switch and rotary operated potentiometer switch(es) to vary the audio output. The present inventive concept uses a variety of mechanical connectors, which couple the rotary switches of the floor device to a hand-operated controller mounted on a microphone or accessory stand. In this manner a performer is able to operate the effects device, with his/her hand, from a more natural standing position during a musical performance, rather than having to crouch down during said performance.

Abstract: A power amplifier (power amplifier) having multiple solid state sub-amplifiers connected in parallel between the power amplifier input and the power amplifier output are described. The signal input to the power amplifier is provided to an RF splitter connected between the power amplifier input connector and the input of each of the sub-amplifiers. The RF splitter splits the input power from the signal input and provides the power to the sub-amplifier inputs through input electrical paths. The input electrical paths from the power amplifier input to the sub-amplifiers are substantially physically identical. Each of the sub-amplifiers drive an input of an RF combiner connected between the outputs of the sub-amplifiers and the output of the power amplifier. The RF combiner combines the output power from each of the sub-amplifiers through output electrical paths, and provides the combined power to the power amplifier output.

Abstract: An ignition wire having low resistance and high inductance includes a ferrite core, a coiled wire surrounding the core, and an insulating sheath, where the high voltage ignition wire exhibits a resistance of 130-210 Ohms/ft and an inductance of 44-104 ?H. The coiled wire may have a diameter of 0.07-0.11 mm, 110-180 turns/in. and comprises a CuNi-based alloy. The coiled wire is preferably made of a CuNi-based alloy having, by weight, 80-95% Cu and 5-20% Ni. The ferrite core may include a core stranding which includes a ferrite core coating. The ferrite core coating may include, by weight, about 5.0-8.4% carbon, 31.7-37.8 oxygen, 1.5-1.7% copper, 0.6-0.8% aluminum, 0.1-0.2% sulfer, 7.0-11.6% zinc, 2.4-3.3 nickel and the balance iron and minor amounts of impurities.

Abstract: A method for producing a uniformly heated electric heating cloth comprising the steps of forming heating threads by dissolving a thermoplastic polymer in an organic solvent, adding an industrial carbon which is produced from acetylene to form a first mixture, grinding the mixture of industrial carbon and thermoplastic polymer, adding a colloidal graphite to form a second mixture, grinding the second mixture, coating threads with the second mixture in a spinneret, heating the coated threads to remove the organic solvent; and interweaving the coated heating threads with non-conducting threads in a perpendicular direction.

Abstract: A resistive pin for use in a voltage probe includes a pin-head that is configured to contact a test point in a device under test, and a resistor that is attached to the pin-head. Other systems are also provided for establishing electrical connections between testing instruments and devices under test.

Abstract: A heat transfer material comprised of a polymeric material and a nitride or oxide is provided and is thermally conductive, but electrically non-conductive. The polymeric material may be silicone rubber, and the nitride or oxide may be aluminum nitride, boron nitride, silicon nitride, aluminum oxide or beryllium oxide. The material is made flexible by adding plasticizer and remains flexible after an extended period of use. A dielectric jacket for an electrical heating cable is thermally conductive and remains flexible so that it can be reused. The heat transfer material can be used on heating devices such as steam tubes and panels, where the heat transfer material does not bond to or adhere to the heated surface, which allows the heating device to be reused.

Abstract: A system for preventing and clearing gutter ice dams includes a plurality of wire holding assemblies, each assembly having a base for attachment to a gutter and a length-adjustable arm for contact with a roof adjacent the gutter. The arm is rotatably and pivotally mounted to the base. The system includes a PTCR heating cable that is held in a desired position by the wire holding assembly arms. The system includes roof and gutter temperature sensors and a moisture sensor. The heating cable is connected to the control unit, the control having a mode selector switch for controlling operation of the cable. In an automatic mode, the heating cable is energized if a roof temperature is greater than a predetermined temperature and a gutter temperature is less than a predetermined temperature. In a timer mode, the heating cable is energized for a selectable time.

Abstract: The invention relates to a floor heating device comprising an electric heating cable extending backwards and forwards underneath a floor surface to be heated. Metal rectangular or square panels are provided with channels extending in parallel in the direction of deposition of the panels. Each metal panel is fitted on its reverse side with an insulating panel in a sandwich construction so that the channels of the metal panel penetrate into the insulating panel material. The assembled panels are deposited on the support of the floor in juxtaposed relationship in the longitudinal and transverse directions such that each channel of one metal panel continues into another channel formed in the adjacent metal panel at the end edge sides of the first metal panel. The heating cable is arranged inside the channels so as to extend from one metal panel to the next backwards and forwards across the floor.

Abstract: A heating element, including a sensor conductor, two resistive conductors, with one resistive conductor arranged on one side of the sensor conductor and an other resistive conductor arranged on an other side of the sensor conductor such that the sensor conductor and the two resistive conductors are substantially parallel and plastic electrical insulation surrounding the sensor conductor and each resistive conductor.

Abstract: A device to protect electronic circuitry from high voltage transients is constructed from a relatively thin piece of conductive composite sandwiched between two conductors so that conduction is through the thickness of the composite piece. The device is based on the discovery that conduction through conductive composite materials in this configuration switches to a high resistance mode when exposed to voltages above a threshold voltage.

Abstract: A mineral insulated heating cable comprising two electrical conductors extending along the lengths of the cable and an array of heating elements distributed along the length of the cable and connected in parallel between the conductors. The heating cable is encased in a metal jacket which waterproofs the overall assembly, the jacket being electrically insulated from both the conductors and the heating elements by for example mica or glass fiber tape sheaths. The metal jacket is extruded directly onto the heating cable, or is extruded around and then drawn down onto the heating cable. Thus the structure can withstand high temperatures and yet is waterproof given the provision of the metal jacket.

Abstract: This invention relates to a high voltage resistance. The resistance comprises at least one organic substrate (21) and a flat conductor (22) with length L, width l fixed to the organic substrate and with a given resistivity &rgr; and a thickness &egr;, the value R of the resistance being equal to &rgr;L/le, the values of the length L, width l being defined such that the mass of the flat conductor (22) is sufficient to resist electrical arcing without exceeding a given temperature. This invention is particularly applicable for current limitation resistances in microwave progressive wave tube emitters, used for example in airborne radar systems.

Abstract: An electrical cable for high-voltage circuits is used in fixed type apparatuses such as office or home appliances. The electrical cable includes a tubular core portion formed of fluorine rubber and a magnetic material mixed therewith. The tubular core portion is wound with a conductive wire. The diameter of the conductive wire is set to be about 40 &mgr;m at the most, so that number of spirals can be more than about 10,000 spirals/m. Under these conditions, even when the electrical cable is flexed, spirals of the conductive wire are prevented from being superposed or stacked. The electrical cable can thus be provided with a high impedance and prevented from noise penetration.

Abstract: An electrical cable according to the present invention is suitable for high-voltage circuits used in fixed-type apparatuses such as office or home appliances. The cable includes a reinforcing thread, which is baked with a fluorocarbon rubber paint, to form a small-diameter cable core portion. The cable core portion is wound with a conductive wire having a wire core portion and a semi-electroconductive wire-coating. Because the conductive wire includes the semi-electroconductive coating, it can be wound densely. As a result, the electrical cable as a whole can be made thinner, while maintaining a high noise-suppressing effect.

Abstract: An ice and snow melting system includes at least one sensor configured for sensing a temperature or moisture associated with an ambient environment and providing a signal indicative thereof. A heater for melting the ice and snow includes a heater wire, a layer of insulation substantially surrounding the heater wire, and a conductive shield substantially surrounding the layer of insulation. A ground fault circuit interrupter is coupled with the shield of the heater. The ground fault circuit interrupter detects a ground fault condition between the heater wire and the conductive shield and provides a signal indicative thereof. An automatic controller is connected to the at least one sensor. The controller includes heater control circuitry receiving each of the sensor signal and the ground fault circuit interrupter signal. The heater control circuitry selectively controls operation of the heater dependent upon the sensor signal and the ground fault circuit interrupter signal.

Abstract: An elongate heater (1) in which a resistive heating element core is surrounded by a first insulating jacket (9) and a second insulating jacket (11). In a preferred embodiment the resistive heating element core comprises a conductive polymer composition (3) and the heater passes the VW-1 flame test. The second insulating jacket (11) may be made from the same material as the first insulating jacket (9). For some applications it is preferred that the second insulating jacket be a thin film, e.g. polyester film.

Abstract: An ice and snow melting system includes at least one sensor configured for sensing a temperature or moisture associated with an ambient environment and providing a signal indicative thereof. A heater for melting the ice and snow includes a heater wire, a layer of insulation substantially surrounding the heater wire, and a conductive shield substantially surrounding the layer of insulation. A ground fault circuit interrupter is coupled with the shield of the heater. The ground fault circuit interrupter detects a ground fault condition between the heater wire and the conductive shield and provides a signal indicative thereof. An automatic controller is connected to the at least one sensor. The controller includes heater control circuitry receiving each of the sensor signal and the ground fault circuit interrupter signal. The heater control circuitry selectively controls operation of the heater dependent upon the sensor signal and the ground fault circuit interrupter signal.

Abstract: A positive temperature coefficient (PTC) resistor composition, comprising: (a) about 3% to about 75% by weight of a binder resin, (b) about 0.5% to about 70% by weight of a temperature activatable semicrystalline polymer, which is a thermoplastic elastomer (TPE) that melts at a relatively narrow temperature range to change from a crystalline state to an amorphous state, (c) about 10% to about 80% by weight of an electrically conductive material in finely particulated form selected from the group consisting of silver, graphite, graphite/carbon, nickel, copper, silver coated copper, and aluminum, (d) about 0.01% to about 80% by weight of solvent material for the composition.

Abstract: A method for thawing frozen road culverts. The first step involves positioning an electrically conductive cable in a road culvert prior to an ice blockage occurring. A connection end of the electrically conductive cable is anchored in an accessible location. The second step involves connecting a power source to the connection end of the electrically conductive cable after an ice blockage of the road culvert has occurred and supplying power to the electrically conductive cable, such that energy generated by power flowing through the electrically conductive cable causes a flow path to be created through the ice blockage in the road culvert.

Abstract: A coil type, noise suppressing high voltage resistor wherein, without applying a releasing agent to the coil core, the adhesiveness of the fluorocarbon polymer in its unvulcanized state is reduced sufficiently so that unwinding of the unvulcanized core, followed by winding of the resistance wire, can be smoothly carried out. On the coil core covered by extrusion coating with a fluorocarbon polymer mixed with ferrite powder, the resistance wire is helically wound. The coil core to which the resistance wire has been applied is then covered in sequence with an insulating layer, a braid for reinforcement, and a sheath. The fluorocarbon polymer is a blend polymer mixture including a reinforcing polymer, preferably an ethylene-vinyl acetate copolymer, which is compatible with the fluorocarbon polymer and can be co-vulcanized therewith. The blend ratio is 5% to 25% by weight of the EVA, based on the total mixture.

Abstract: An immersion heater for corrosive fluids includes an electrically resistive material strand operative upon connection to a source of power to provide heat. A thermally conductive electrically insulating fill material is disposed around the electrically resistive material strand. An electrically conductive sheath encases the fill material. A tubular jacket of a flexible chemically inert material encases the electrically conductive sheath. A fluid flow passage is defined between the tubular jacket and the sheath for allowing a fluid to flow therethrough. The fluid is a purge gas that flows between the sheath and the jacket in order to remove any corrosive fluid which may have penetrated the jacket. A method for manufacturing an immersion heater is also disclosed.

Abstract: There is disclosed an electrical component having an axial direction and two ends for making electrical contact with another component comprising a plurality of electrically conductive fibers in a matrix, the plurality of the fibers being oriented in the matrix in a direction substantially parallel in the axial direction of the component and being continuous from one end of the component to the other end to provide a plurality of electrical point contacts at each end of the component, wherein the component further includes magnetic particles.

Abstract: An engine ignition cable includes a stretching resistant central core over which an intermediate layer made of a mixture of silicone with ferric oxide powders with a ratio of 4:1 is fit. A high conductivity wire is then wrapped around the intermediate layer, preferably in a helix form, to provide a low impedance current path having an impedance of 0.8 k.OMEGA. per meter length. An insulation outer layer or sheath which may be made of silicone or rubber, is then used to enclose the cable. The use of the high conductivity wire causes a strong electro-magnetic radiation when in operation which can be counteracted, at least partially, by the magnetic field established by the intermediate layer that consists of ferric oxide powders.

Abstract: A data bus for a fault tolerant avionics digital autonomous terminal access communications system is provided with a terminating resistor for absorbing or sufficiently attenuating signals incident on it so that they are not reflected back into the transmission line at amplitudes where they would cause distortion of the data signal. The data bus and terminating resistors are designed to continue providing full operational capability even if the electrical resistance of the terminating resistor increases by about 5%. The terminating resistor has at least about twenty resistive elements connected in parallel across two conductors in the data bus at one end thereof. Each resistive element includes a non-conductive substrate having a face surface on which is deposited a conductive film to produce a primary resistor.

Abstract: An apparatus for sealing the end of an elongate cable such as an electrical heating cable which comprises a clip-shaped insert positioned within a tubular-shaped housing. Gripping members and pre-gripping members project from the interior surfaces of the arms of the insert and act to grip a cable when it is inserted into the device. A locking mechanism on the insert engages locking teeth on the housing and serves to hold the insert in position. A conformable gel component may be present. The apparatus provides high pullout force, as well as environmental sealing, for cables such as electrical heating cables or power cables.

Abstract: A coaxial type electrical resistor has a cylindrical conductor, a cylindrical insulator inserted into the opening of the conductor and a cylindrical resistor inserted into the opening of the insulator. Since the insulator is between the conductor and the resistor, a distance between the conductor and resistor may be small and magnetic flux leakage reduced. Thus the resistor has a small inductance and is appropriate as a high frequency large current resistor.

Abstract: In order to provide a coil type high-voltage resistive wire having a lower resistance than and a noise preventing performance similar to a prior art resistive wire while maintaining an inductance level without increasing a diameter and a winding pitch of a resistance wire, a core (3) consists essentially of a center reinforcing core (1) which is obtained by twisting three aramid fibers of 1000 denier and a ferrite core (2) having an outer diameter of 1.3 mm or smaller which is obtained by extruding a mixture of resin or rubber base and ferrite powder around the center reinforcing core (1). A resistance wire 5 made of a copper-nickel alloy wire having a diameter of 35 to 55 .mu.m and an electrical resistivity of 5 to 35 .mu..OMEGA..cm is wound around the core 3 at a pitch of 10000 winds/m or larger in a direction normal to the longitudinal axis of the core (3), so that the resistance value of the resistance wire (5) as a conductor can be set at 4 to 7 k.OMEGA./m.

Abstract: A road heater comprising (1) a linear heater which is comprised of a linear heating element and a flexible electrically insulating layer formed on the entire periphery of the linear heating element, and (2) an outer textile structure such as a braid which covers the entire periphery of the linear heater. The road heater has a compressive yield load (Lc) of at least 1,000 kg. The outer textile structure is made of a thermoplastic synthetic fiber, preferably, a polyester monofilament, having a melting point of at least 200.degree. C. and a single fiber fineness of at least 1,000 deniers. The linear heating element preferably comprises a flexible heat-generating mixed spun yarn composed of stainless steel fibers and heat-resistant electrically non-conductive fibers.

Abstract: An improved welding rod for joining plastic materials is provided. The welding rod includes a core of electrically resistive fiber, and a winding of electrically resistive fiber separated by a plastic barrier layer. Also provided is a method for joining plastic materials using the welding rod.

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 parallel, zone-type heating cable wherein thermally-controlled ferrite reed switches in each zone regulate current flow to heating elements aligned in parallel with each other. Two parallel conductors deliver current to the switches and the heating elements. A dielectric insulation material separates the conductors from each other and the heating elements. The heating cable may further include a component having a particular temperature coefficient of resistance aligned in parallel with the switch to further regulate current flow to a positive but lesser level when the switch is open.

Abstract: An electrostatographic reproduction machine wherein at least a portion of the wiring is formed from partially carbonized polyacrylonitrile filaments having a resistivity of between 1.times.10.sup.2 and 1.times.10.sup.10 ohm-cm. Preferably, the interconnects from the power source to the corona generating means are partially carbonized polyarylonitrile wires.

Abstract: A failure-resistant electrical ignition system cable comprises first and second terminal contacts for contacting a source of ignition pulses and contacting the predetermined destination of these pulses, respectively; a plurality of flexible ignition conductors connected between the first and second terminal contacts, each of the ignition conductors being capable of electrically communicating the ignition pulses between the terminal contacts, each of the ignition conductors comprising an electrically-inert center, an elongated conductive wire spirally and interstitially wound around the center for substantially the full length thereof, each of the ignition conductors then being twisted about each other so as to provide repeated electrical contacts of the conductive wire of each whereby electrical continuity between the terminal contacts may be maintained despite the occurrence of one or more electrical discontinuities; the outer exposed surfaces of the twisted ignition conductors being electrically insulated b