Abstract: An electronically controllable resistor (ECR) which functions as a fixed or variable resistor over a wide range of operating conditions. The value of the resistance may be altered in a highly linear fashion by altering a digital input thereto. The ECR utilizes an array of transmission gates, preferably having a uniform inherent resistance and preferably fabricated using CMOS technology which are grouped in commonly controlled groups. Each group preferably contains a number of transmission gates which relates to the numbers of transmission gates in other groups in a binary fashion. The source of digital control signals is preferably provided by a digital memory device which can be integrated with the transmission gate array. An operational amplifier can also be provided on the chip to form a complete neural processing element for inclusion in large neural networks.

Abstract: An improved frame supported resistor grid used for dynamic braking of electric motors is provided. The resistor grid has a metal frame and fan-folded strips of resistance material arranged in columns within the frame. The strips of resistance material are supported by studs affixed to the folds of the strips and the studs are, in turn, supported in ceramic bushing insulators. An intermediate member is affixed to the frame and receives the individual ceramic bushing insulators.

Abstract: An electrical resistor which is fabricated from traces of resistive material on a substrate of insulating material. The traces are interconnected electrically in series by first links and in parallel by second alternating links, which are connected to different terminals on the substrate. The second links are cut, preferably by laser trimming, so as to select the value of resistance of the resistor by reducing the number of traces connected in parallel and increasing the number of traces connected in series. Where the resistance of each trace is "R", the value of the resistance is adjustable by severing the second links from R/n to nR, where n is the number of traces.

Abstract: A flat resistance for a blower control unit of an automobile air conditioner, and a blower control unit using the same. The flat resistance includes: a porcelain enameled metallic substrate including a flat head portion, having an edge and one surface, and parallel terminal supporting portions projecting outwardly from the edge of the head; a resistance circuit printed on the one surface of the head portion, the resistance circuit including a plurality of resistances electrically connected in series; a temperature fuse, interposed in the resistance circuit, for being tripped to break the resistance circuit when the porcelain enameled metallic substrate becomes overheated; and terminals, printed on both the head portion and the terminal supporting portions, each terminal being connected to one end of a corresponding one of the resistances.

Abstract: Six curved hanging electrical heater panels made of tungsten or molybdenum are arranged to form a hollow cylinder, and are supported at their upper ends by electrical connectors. The hanging panels are electrically interconnected at adjacent lower corners by removable links. Six phase electrical current is applied to the hanging panels through the respective upper connectors, with phases of opposite polarities being applied to diametrically opposed panels. The net current flow through the removable links is zero, enabling the links to be designed to fail electrically and/or mechanically before the panels, thereby protecting the panels from electrical burnout and mechanical damage. Each removable link includes a unique arrangement of a link member, two pins, and a wedge which tightly interlocks the pins, link member and panel corners together.

Abstract: A dual element comprises two electrical heating elements of different ratings. Each heating element has first and second terminals. The second terminals of the two heating elements are secured to a common clip, which is wired into an appropriate electrical circuit. The heating element first terminals are secured to respective clips. A second wire of the circuit is connected to a selected one of the first terminal clips, thereby determining the power rating of the dual element. A jumper is provided that is selectively installable between the two first terminal clips. With the jumper installed, the second wire may be connected to either of the first terminal clips to thereby place the two heating elements in parallel. The rating of the dual element is then the sum of the ratings of the two individual heating elements. In that manner, the dual element is operable at three different ratings.

Abstract: For use in a welded resistor grid assembly moving a plurality of generally parallel, relatively think plate-like metal elements disposed between a pair of spaced-apart insulating support members having a plurality of slotted openings in their opposing sidewalls, a metal element having a substantially rectangular plate-like body of predetermined width, a coplanar flat segment of the same width at one end of the body, a laterally offset flat segment of the same width at the opposite end of the body, the upraised side of the later segment having a flat surface adapted to be joined by a seam weld to the flat surface of the other side of the coplanar segment of another duplicate element after two such elements are placed side by side with opposite orientation so that the offset flat segment of one adjoins the coplanar flat segment of the other, and a border segment of the same width contiguous and generally coplanar with a first one of the flat segments, the border segment being adapted to enter a slotted opening

Abstract: A high value, precision resistor (10) includes a doped region (18) having a boustrophedonic (folded or meandering) shape formed in a substrate (12). At least one section of the doped region (18) is formed by implantation using a focused ion beam. Where the entire doped region (18) is formed by the focused ion beam, the length thereof is selected to be large (10 to 100 times the width of the boustrophedonic shape) to maximize the accuracy of the resistor (10) by averaging over variations in grain size and implant dose. Alternatively, a probe resistor (32) and a plurality of similar unconnected doped sections (28) may be formed by means such as photolithography and flood ion implantation. The probe resistor (32) is measured at the desired operating temperature to determine the ratio of the measured resistance to the desired design resistance value.

Abstract: An electrical resistance device includes a conductive metal pattern carried on an insulating surface. A portion of the conductive metal pattern includes a two-dimensional array of areas devoid of conductive material ("voids") within a mesh of conductive material. Typically, the voids are hexagonal and are arranged such that the adjacent edges of adjacent hexagons are parallel to each other and spaced apart a distance not more than about 0.10 in. The hexagonal voids typically are arranged so that the centers of sets of three adjacent voids lie on the corners of equilateral triangles.

Abstract: A resistor divider network is disclosed having two or more thin or thick film resistive elements deposited on a substrate. Each of the resistive elements is divided into a number of resistive subelements which are interleaved so as to improve the temperature coefficient of ratio (TCR tracking) and improve the thermal coupling which greatly improves the ratio constancy over a wide range of input voltage. There are an odd total number of resistive subelements, the subelements of each main element having equal resistances.

Abstract: An electric resistance heating element for heating fluids includes a plurality of ring-shaped members made of a ceramic material having a positive temperature coefficient (PTC) disposed in concentric generally coplanar relationship, one around the other, and spaced apart from each other to form through passages for fluid flow therebetween. Electrode layers are formed at the two opposite ends of each ring and a pair of electrically conductive securing ring members are each securely soldered to a respective one of the electrode layers. Each securing ring member is integrally formed with two diametrical cross members soldered to each ceramic ring-shaped members and with each cross member having spaced grooves radially engaging and positioning the ring-shaped ceramic members. The outer periphery of each securing ring member incorporates a plurality of radially extending lugs for mounting the heating element for use and for making electrical connection between the securing ring member and a power supply.

Abstract: A resistor grid for diesel electric locomotives and the like has a rigid frame comprising outer metal side pieces and one or more pairs of inner metal side pieces spaced from each other, and columns of resistor ribbon fan-folded between each outer and outermost inner side piece, and between certain inner side pieces. Supporting means interengaging each fold of the ribbons are insulated from and carried on each side by a metal strip which rides on its adjoining side piece so as to accommodate expansion of the resistor ribbon. The ribbon is indented between folds to stiffen it and increase its span and may by provided with a support rod centered between its side pieces. The resistor grid is preferably positioned in forced air cooled resistor banks face-to-face with conventional narrow span grids, and improves the cooling of such conventional banks.

Abstract: The disclosure relates to integrated circuit resistors and matched resistor pairs wherein each resistor is split into plural segments, each segment having a separate field plate thereover, each segment having the field plate associated therewith connected to the non-common node thereof. In the case of the matched resistor pair, the interconnections between the segment of each resistor overlap. The segments are preferably substantially rectangular in shape with the major axes of all segments parallel to each other.

Abstract: A resistor network coupling two terminal leads and adapted to be fabricated on an integrated circuit. A plurality of N-sided meshes are each formed by N resistor elements linked at network nodes. Some of the resistor elements can be cut by a laser under computer control to select a desired resistance value of the network.

Abstract: An electrical cartridge heater includes a flat rectangular core of mica. A resistance wire is helically wound around the mica core. A cover sheet of mica is placed on one face of the wound core so that a return wire extends back without shorting against the other wires. The mica core is received in recesses in head and slug end bushings to position the element centrally within a cylindrical shell. A granular fill surrounds the core and heating element within the shell.

Abstract: An electrically heatable hair wrapper capable of being cut to any predetermined length from a flat, elongated, flexible base carrying a plurality of parallel resistance heating circuits. The circuits extend along the length of the base in a periodic serpentine pattern with the opposite ends of each pattern being electrically connected to continuous parallel buses extending along the longitudinal edges of the base. The flexible base is provided with indicia for indicating where the base and buses may be cut intermediate each adjacent pair of serpentine patterns so as not to destroy the continuity of the selected resistance heating circuits. A bendable, shape-retaining, cuttable wire along each longitudinal edge of the base outwardly of the parallel buses holds the wrapper in any desired shape. A longitudinally flexible flap integrally formed with at least one longitudinal edge of the base is foldable over the base to retain a hair tress between the base and flap during use of the wrapper.

Abstract: A grid assembly for converting electrical energy to heat and then dissipating same. A plurality of parallel grid members include outwardly extending legs received in holes provided on mutually facing surfaces on polyester glass insulator members. The grid members are arranged in a continuous serpentine path from an input to an output terminal. The grid members are of sheet metal construction with the cylindrical legs formed by a radiused sheet metal configured leg portion of one grid member positioned adjacent an identical configured and mutually opposed leg portion of an adjacent grid member. The main body of each grid member extends from the legs through a flat portion and then through a diverging end portion spacing the main bodies of the grid members apart. In an alternate embodiment, the grid members are arranged with different lengths to provide a particular sized and configured grid assembly.

Abstract: A band-form, electrically heat-generating apparatus having two parallel electrodes and resistance elements intervened therebetween over the entire length of the electrodes, and connected to both the electrodes in parallel and individual feeding points on each of the respective electrodes, which apparatus is characterized in that the feeding point to one of the electrodes and that to another of the electrodes are located at diagonal positions relative to the parallelogram formed by the two electrodes and the outermost two of the resistance elements to form a heat-generating unit. A plurality of such a heat-generating apparatus may be formed by connecting such a heat-generating unit in series to form a heat-generating apparatus; and the electrically heat-generating apparatus may further be provided with a circuit for detecting or protecting voltage abnormalities. With the above apparatus, a more uniform heat generation is possible as compared with conventional apparatus.

Abstract: A coated layer type resistor device having a first resistor element and a second resistor element. The ratio between the resistances of the first and second resistor elements is selected to be greater than a predetermined ratio. The first resistor element is formed on an insulator substrate and consists of a resistor layer and end conductor electrodes at the ends of the resistor layer, while the second resistor element is formed on the substrate and consists of a resistor layer, end conductor electrodes, and a plurality of intermediate conductors. The distance between adjacent ones of the intermediate conductors and the distance between one of the end conductor electrodes and the adjacent intermediate conductor in the second resistor element is equal to the distance between the end conductor electrodes in the first resistor element, so that the temperature coefficient property of the resistance is equal in both the first and second resistor elements.

Abstract: Elongate electrical devices, comprising two conductors with electrical elements connected in parallel between them, have improved performance if the power supply is connected to one conductor at the near end and to the other conductor at the far end. Particularly useful devices are heaters, e.g. PTC conductive polymer heaters. The power supply is connected to the far end of the device through a connection means whose electrical properties can be correlated with those of the device in order to obtain a wide range of useful results. For example the connection means can have PTC, NTC or ZTC character and can be a simple conductor or another elongate device. The power supply can be DC or single-phase, two-phase or three-phase AC.

Abstract: The resistor assembly includes a plurality of resistor sections each in the form of resistive plates in which slots have been cut to provide a continuous resistive element of low inductance. The resistor sections are stacked together with thin insulating sheets separating adjacent resistor sections. The resistor sections are serially interconnected. Taps are provided on selected resistor sections to form a plurality of serially connected resistors in which each resistor is electrically isolated from an adjacent resistor but closely thermally coupled thereto. The resistive plates are bound together by discrete bands of an insulating material such as glass cloth tape. Epoxy impregnation allows the resistor assembly when connected in shunt with series connected superconductive coils to be immersed in the liquid helium of a magnet cryostat without causing excessive pressure rise during a quench event.

Abstract: A heat treating furnace having a work chamber of circular cross-section and having banks of electric resistance heating elements formed by rigid and elongated graphite bars. The graphite bars of each bank are interconnected so as to form an octagon located closely adjacent the circular wall of the work chamber and closely approximating the circular shape of the chamber. As a result of the octagonal arrangement, ring-like banks of rigid graphite elements may be space longitudinally along the circular work chamber to enable front-to-rear temperature trim zones to be established in the chamber.

Abstract: An input device for use in a display unit serving as a terminal of a computer has first and second insulating sheets and an insulating spacer sandwiched between the first and second sheets. The first sheet has first terminal leads on its both ends, while the second sheet has second terminal leads which extend in perpendicular relation to the first terminal leads. The upper surface is covered with a flexible, insulating, protective sheet. The spacer includes lattice-like conductors and consists of a material having cells of gas and elasticity and flexibility such as silicone foam. A fixed voltage is alternately applied across both ends of the first sheet and across both ends of the second sheet. When the protective sheet is depressed at a point P as by a depression pen, the position of the point is measured and represented by means of X- and Y-coordinates.

Abstract: Small portable electrical resistance heated radiant heating unit useful for insertion in tube bores to effect localized high temperature heating. Useful for the internal heating of tubes and tube/sleeve assemblies in steam generators, having bores as small as 0.75 cm. or less, for brazing, stress relieving, and other applications.

Abstract: A high temperature electric furnace has along its side walls vertical hollow electric resistance heating tubes (57) interconnected in serpentine fashion by conductive bridge plates (55). The tube ends and bridge plates are so contoured as to provide substantially uniform resistance along all possible current paths, thereby to avoid preferential current conduction with localized overheating. The bridge plates (55) and/or the tube ends are supported by air-cooled hollow hangers (28,45).

Abstract: An apparatus relating to a voltage divider having one or more Kelvin connection taps, including first and second spaced terminals and a current carrying resistor between the first and second terminals. A third terminal is spaced from the resistor and the resistor has at least one conductive but non-current-carrying peninsula extending from a junction on the side of the resistor and connecting with the third terminal to produce a Kelvin connection tap. A cut is made only in the non-current-carrying peninsula along the path having a component parallel to the side of the resistor from which the peninsula extends and shading the junction of said peninsula and the side from the third terminal, to adjust the interconnection of the third terminal with the resistor and vary the voltage output without varying the resistance of the resistor. An extension of this cut may be made parallel to the edge of the peninsula to further increase the adjustment.

Abstract: A cooled resistor pack for a dynamoelectric machine wherein cooling water is passed through ducts in a conductive block and plurality of connectors are mechanically attached to the conductive block but electrically insulated therefrom and nichrome wires of varying length and varying in number electrically join the connectors to the conductive block and individually insulated brush segments, which have individual strands and the brush segments are connected to separate connectors in such a manner that the resistance between the brush segments and the block decreases from the trailing end segments to the leading end segments of the brush.

Abstract: The heater of the present invention includes a paper or plastic substrate on which is printed a semi-conductor pattern (typically a colloidal graphite ink) having (a) a pair of longitudinal stripes extending parallel to and spaced apart from each other and (b) a plurality of identical bars spaced apart from each other and extending between and electrically connected to the stripes. A metallic conductor (typically copper stripping) overlies each of the longitudinal stripes in face-to-face engagement therewith, and the conductors are held in tight engagement with the stripes by a sealing layer that overlies the metallic conductors and is sealed, at opposite sides of the semi-conductor stripe associated with the particular metallic conductor, to portions of the substrate that are free from the printed semi-conductor pattern.

Abstract: An apparatus relating to a voltage divider having one or more Kelvin connection taps, including first and second spaced terminals and a current carrying resistor between the first and second terminals. A third terminal is spaced from the resistor and the resistor has at least one conductive but non-current-carrying peninsula extending from a junction on the side of the resistor and connecting with the third terminal to produce a Kelvin connection tap. A cut is made only in the non-current-carrying peninsula along the path having a component parallel to the side of the resistor from which the peninsula extends and shading the junction of said peninsula and the side from the third terminal, to adjust the interconnection of the third terminal with the resistor and vary the voltage output without varying the resistance of the resistor. An extension of this cut may be made parallel to the edge of the peninsula to further increase the adjustment.

Abstract: An electrical network containing at least one electric resistor, includes a support foil and at least one resistance layer coating the support foil forming the at least one electric resistor. The support foil and resistance layer are folded along a zig-zag line forming two outer surfaces of the resistance layer. Contact layers are each disposed on a different one of the outer surfaces of the resistance layer, a plastic layer is applied on the contact layers, and outer contact layers each make contact with a different one of the contact layers. A method is also provided for producing the same.

Abstract: A flexible barium titanate ceramic PTC heater for use in, for example, an intake pipe of an internal combustion engine to heat the air-fuel gas mixture is formed as a thin disc-shaped ceramic sheet constituted by a plurality of individual coplanar ceramic segments having interior edges positioned in spaced side-by-side relationship. The juxtaposed edges of the ceramic segments are united to each other by a flexible, heat-resistant, electrically non-conductive rubber band disposed in the space between the segments and bonded thereto by an electrically non-conductive adhesive to form the segments into a thin disc-shaped sheet which can be flexed without causing flexing of any of the individual segments. The ceramic heater is positioned in a metallic casing with one planar face thereof bonded to the inner surface of the casing by an electrically conductive adhesive. A stainless steel wool cushioning member engages the other planar face of the ceramic heater to support the heater in the metallic casing.

Abstract: A Hybrid Integrated Circuit package (11) typically includes a circuit substrate or article (12) on which are formed thin film components (17, 18, 19) of a circuit (22) and to which is bonded at least one semiconductor chip (21). Prior to bonding the chip (21) to the article (12) the circuit (22) undergoes various tests and adjustment operations. An electric element, preferably a resistance element (36), is formed on the article (12). The element (36) is functionally independent of the circuit (22) on the article (12). A first, initial value of the element (36) marks the article (12) as belonging to a first group of articles having first circuit characteristics. The initial value of the element (36) is selectively altered to a second value upon a determination that the article (12) has circuit characteristics other than those of the first group. In the described preferred embodiment the first group is a group of electrically acceptable articles (12), while other characteristics are those of defective articles.

Abstract: An improved electrical heating element is constructed to increase the amount of electrical wire per unit space available for plug-type convection heating units. The heating element includes a metal frame structure with a plurality of spaced support elements and a plurality of spaced removable cross bars connected thereto. A plurality of ceramic heater support blocks, each of T-shape in plan, with spaced end faces are arranged end to end and have undercut grooves which receive a cross bar and are interposed between the support elements. A continuous electric resistance heating wire has a series of parallel spaced inverted U-shaped wire sections. The wire sections are arranged in groups. Each block has a support boss of reduced width adjacent one end face adapted to extend between the strands of a section of the heating wire. Each block has a pair of spaced bosses adjacent to its other end face which extend laterally outward of the support boss.

Abstract: A dynamic braking resistor as shown and claimed in U.S. Pat. No. 2,680,178 in which the insulator blocks (226) in this new disclosure are formed of a hot-molded organic compound instead of steatite or asbestos. This allows the insulator blocks to be securely mounted to the frame (210, 212), and allows the elimination of the springs, spring cups and pressure plate. In addition, the extra insulative mica sheet required by the above patent is eliminated without loss of protection from short circuits. However, in order to protect the insulator blocks from the heat generated by the resistor ribbons (218, 220), the support clips (232) are made longer to allow more expansion of the ribbons and to hold the ribbons further away from the insulator blocks. In an alternative embodiment, three resistor ribbons (234, 236, 238) are employed, and each support clip (240) supports one reflex bend of all three ribbons.

Abstract: An electric resistance heating element is formed by a molybdenum disilicide wire loop formed by separate lengths of the wire having ends positioned together and butt welded to the end of a molybdenum disilicide connecting wire of larger diameter than that of the lengths. The lengths diverge from each other so they are electrically separated. Electrical connections with the free ends of the separate lengths of wire can provide for electrically powering the loop.

Abstract: A press platen has a press plate and a cover plate between which is sandwiched a heater plate formed with a generally uniform array of cylindrical recesses in each of which is received an electrically energizable heater capsule. The heater plate is electrically but not thermally insulated and conductor foils applied to opposite faces of this plate but insulated from the press and cover plates are connectable to a source of electricity for energizing the heater capsules.

Abstract: An improved electrical heating element is constructed in such a manner as to increase the amount of electrical wire per unit space available for plug-type convection heating units. The plug uses a rectangular-shaped frame which has a plurality of spool covered rods evenly spaced along the length of the frames and extending across the width. The spools are slidably attached over the rods and have an insulated spacer on each side of the spool. The heating wire has alternate coiled and straight sections and is wound over and held to each spool by a retention wire and a groove in the spool. The rods are spaced at such a distance from each other that there is a straight section of heating wire at each spool with the coiled sections located between adjacent rods.

Abstract: A heated hair straightener has a handle connecting to an electric source and a pair of scissor-like clamp housings pivoted on the handle and having facing coverplate surfaces for clamping and straightening the hair. This combination has an improvement in the heater sub-assembly fitting in one of the housings and formed as a sandwich arrangement including an aluminum coverplate, a copper elongated heater plate forming a first electrode connected to one side of the line and electrically insulated from the coverplate by a thin dielectric film. Plural PTC heater pellets are aligned on the heater plate and held by an insulating locator panel having cut-outs fixing the pellets on the heater plate. A second electrode, formed as a corrugated stainless steel spring plate covers and abuts the PTC pellets and is connected to the other side of the line. Next is a phenolic or ceramic insulator member with a recess for the corrugated spring plate to fit and abut therein.

Abstract: A terminal block for simplified wiring of an electrical immersion heater assembly by providing for either single phase or three phase wire-up in opposite faces of the block. The terminal block has an electrically insulating body of disc-like configuration with three recesses defined in a first face of the block, each recess adapted to receive a lead connecting strap having a pair of apertures. Each of the three recesses has two bores extending into the body, the apertures of the straps alignable with the bores, for receiving leads of three separate heating elements through the apertures and into the bores for three phase wiring in the first face. The opposite face has an X-shaped recess which encompasses only four of the six bores for single phase wiring of four leads of the heating elements with a pair of curved straps. The body is of conical frustrum shape for better sealing characteristics and includes two additional bores adapted for receiving thermowells.

Abstract: An electrical infrared radiant heater in which a heater assembly includes an extruded ceramic holder having parallel holes, certain of which receive heating element wires through such holes. The ends of the heating element wires extend outwardly of the holder on both sides and are joined to each other so as to form a resistance element connected to a source of current. A casing carries the heater assembly.

Abstract: In the present device, a base member is included which has channels formed therein to hold lead wires. In the preferred embodiment a metal foil resistor member, having termination land sections, is secured to the base member to form a fourth side for each channel, thereby securely locating the lead wires in the channels and the lead wires are firmly connected to the termination land sections of the foil resistor. Accordingly with respect to the foil resistor assembly: there is good physical strength to withstand external forces; the resistor reliability is enhanced; the fabrication is simplified; and the resistance range capability is increased.

Abstract: An electric heating element for electric resistance furnace comprises a plurality of heater frames which consist of conductive strip material having a sectional shape selected from leg angle-section, channel-section, lip-section, T-section, U-section, V-section, I-section, H-section, Z-section, and W-section and having electric resistance. The heater frames have a configuration coinciding with a sectional shape of an inner wall of a heating chamber of the furnace, and are made and arranged to have an opening portion. Conductive connecting rods are adapted to connect both ends of each of said heater frames to alternatively adjacent ends of adjacent heater frames so as to constitute a single wire resistance body of said heater frames, and a conductive rod connected with one end of said wire resistance body is arranged to pass through said opening portion of said heater frames and facing a power source terminal together with the other end of said wire resistance body.

Abstract: The unit comprises a fan-folded ribbon of resistance material supported by parallel insulating members at the ends of the loops. Each length or fold is formed with a transverse reverse bend or offset dividing the fold into major and minor lengths, which are not coplanar.

Abstract: A positive temperature coefficient (PTC) resistance heater assembly is used in combination with an angle of attack vane to provide automatic means for maintaining the temperature of the vane at a level which will de-ice the vane. The heater assembly is embedded in a recess in the vane and is made up of a plurality of individual PTC resistors connected electrically and mechanically in parallel by flexible electrically conductive perforated strips which permit the individual resistors to move relative to each the other under thermal stress and which also permit the encapsulation of the resistors in a suitable thermally conductive, electrically oinsulative material that is sufficiently resilient to permit the individual resistors to expand and contract relative to the vane during use.

Abstract: Self-regulating heating element comprising one or more PTC resistors enveloped by a synthetic-material/filler mixture which has a good heat conductivity such as an MgO-SiO.sub.2 -silicon rubber mixture.

Abstract: A frame supported grid resistor having a plurality of resistors of the ribbon type has located between adjacent ribbon resistors, strips of conductive material containing nonconductive bushings which engage and separate the adjacent ribbon resistors.

Abstract: A continuous composite web from which electrical low temperature heating mats can be produced by transverse cutting at certain positions and possibly by effecting an edge insulation and attaching electrical connections. A method for the production of such webs is also disclosed. The web consists of resistance foil material between two insulating foil layers which are joined in the areas of direct contact to secure the resistance foil. The resistance foil material is in the form of parallel, continuous, longitudinal strips and transverse strips extending transversely to said longitudinal strips at desired intervals and connected thereto to form electrical connections between adjacent foil strips. The transverse strips extend substantially across the total width of the web and can be in the form of an insulation strip having flat foil conductive pieces on the insulation strip.

Abstract: A high voltage gas insulated circuit breaker in which a resistance shunts the main interrupter contacts to control the magnitude of the surge voltage experienced when the interrupter is closing. The resistance includes a resistor switch comprising a plurality of stacks of resistor segments connected in parallel. The smaller surface area of the segments tends to resist cracking due to mechanical thermal stresses and provides a higher resistivity thereby being capable of withstanding more voltage. The parallel stacks of resistor segments provides for a more compact resistor switch without sacrificing the basic operational requirement.

Abstract: An electric resistance heating element, comprising at least two elongated dielectric bodies, each having a plurality of openings extending longitudinally thereon in radially displaced, parallel relation. Three metal pins fit into openings in the dielectric bodies and at least certain maintain the latter in longitudinally aligned relation. A resistance wire is wound on each of the bodies, each wire having longitudinally spaced terminals. One of the terminals of each resistance wire is electrically connected to one pin; the opposite terminal of one resistance wire is electrically connected to a second pin; and the opposite terminal of the other resistance wire is electrically connected to the third pin, whereby the one pin serves as a common electrical connection for both resistance wires, and the second and third pins serve as separate electrical connections to the respective resistance wires, whereby separate electrical circuits may be established within the heating element.

Abstract: A plurality of resistance elements arranged in an n-row by n-column matrix are of substantially equal lengths and widths. The sides of the resistance elements which are in common rows and columns are colinear and first and second electrodes are provided at substantially the same location on each resistance element. The electrodes of the resistance elements are connected in a manner such that a series connection is formed between resistance elements belonging to different adjacent columns in the matrix between two sets of n external terminals.