Thermistor Type Patents (Class 338/22R)
  • Patent number: 5856773
    Abstract: A PTC device suitable for attachment to a terminal of a battery. The device contains a PTC component which has a shape with an outer periphery and an inner periphery which defines a first opening in the center of the PTC component. The PTC component is made from a laminar PTC resistive element which is composed of a PTC conductive polymer composition, a first laminar electrode which is attached to a first face of the resistive element, and a second laminar electrode which is attached to a second opposite face of the resistive element. Also part of the device are a first conductive lead which has a first part which is attached to the first electrode, and a second part which extends into the first opening, and a second conductive lead.
    Type: Grant
    Filed: November 4, 1996
    Date of Patent: January 5, 1999
    Assignee: Raychem Corporation
    Inventors: Daniel A. Chandler, Johnny Lam
  • Patent number: 5854471
    Abstract: A PTC (positive temperature coefficient) thermistor heating apparatus includes two or more heating blocks, each heating block including a PTC thermistor and radiating elements disposed in contact with at least two surfaces of the PTC thermistor; an elastic element disposed between the heating blocks; and insulating elements for holding portions of the radiating elements at the ends of the heating blocks; wherein the heating blocks are biased from each other by an elastic force of the elastic element.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: December 29, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tomoaki Tadokoro, Akira Mizoi, Shinji Omura, Tomomi Okada, Osamu Watanabe
  • Patent number: 5852397
    Abstract: A circuit protection device which comprises first and second laminar electrodes; a laminar PTC conductive polymer resistive element sandwiched between the electrodes; a third laminar conductive member which is secured to the same face of the PTC element as the second electrode but is separated therefrom; and an electrical connector which connects the third conductive member and the first electrode. This permits connection to both electrodes from the same side of the device, so that the device can be connected flat on a printed circuit board, with the first electrode on top, without any need for leads. The connector is preferably a cross-conductor which passes through an aperture in the PTC element, because this makes it possible to carry out the steps for preparing the devices on an assembly which corresponds to a number of individual devices, with division of the assembly as the final step.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: December 22, 1998
    Assignee: Raychem Corporation
    Inventors: Chi-Ming Chan, Michael Zhang, Daniel Chandler, Shou-Mean Fang, Dennis Siden, Mark Thompson
  • Patent number: 5841341
    Abstract: A dielectric clip for holding a PTC device is dimensioned and shaped to occupy a three-dimensional space envelope that provides a close fit in a fuse socket.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: November 24, 1998
    Assignee: Therm-O-Disc, Incorporated
    Inventor: Jeffrey A. West
  • Patent number: 5832592
    Abstract: A plurality of flow sensors are fabricated on a single substrate. The substrate is laid out to provide the proper physical relationship of the individual sensors. The resulting multiple sensor structure may be effectively used as a respiration detector by positioning a different sensor element at each of the airflow orifices (i.e., two nostrils and mouth) of a patient. In the preferred embodiment, the sensors are thermoresistive elements, which are screened on the substrate using conductive ink. The change in temperature of the air flow in relation to the ambient at each orifice provides an indication of the flow and may be used to determine the extent of the flow. The substrate is packaged in a single piece adhesive strip which provides ease of proper attachment by the patient.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: November 10, 1998
    Assignee: Edentec, Inc.
    Inventors: Bruce Bowman, Peter Stasz
  • Patent number: 5835004
    Abstract: Improved tape assemblies for delivering electrical devices to work stations at which the devices are installed. Each of the devices comprises a laminar electrical component sandwiched between two laminar metal members, and is preferably a PTC circuit protection device. In the assemblies, the electrical components are discrete components, but they are contacted by, and linked together through, laminar metal members which, after the assembly has been divided into separate devices, provide leads which contact and extend away from the electrical component. Preferably the metal members are prepared by cutting and forming a single strip of metal. Preferably the assembly is free from any longitudinally continuous carrier strip which much be discarded after the devices have been separated from each other. Preferably, the assemblies are sufficiently flexible to be wrapped around a reel and unwrapped at the work station.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: November 10, 1998
    Assignee: Raychem Corporation
    Inventors: James P. Gemperle, Richard A. Herms, Bengt Nyman, Irwin Zahn
  • Patent number: 5831251
    Abstract: A heater unit 1 has a plurality of flat heaters 11 adjacently arranged side by side and having common upper and lower surfaces. The thickness T of the heaters 11 is substantially uniform. Each heater 11 has an adjacent end surface 111 which faces toward an adjacent end surface 111 of the adjacent heater 11. The heater unit 1 also has upper and lower electrodes 21 holding the heaters 11 and respectively attached to the upper and lower surfaces of the heaters 11. The adjacent end surfaces 111 of the heaters 11 adjoining each other, and the upper and lower electrodes 21 form an air gap 12 therebetween. The creepage distance L along each adjacent end surface 111 is larger than the thickness T of the heaters 11. The dielectric strength of the heater unit 1 depends on the creepage distance L. The thickness T of the heaters 11 can be decreased without decreasing the dielectric strength of the heater unit 1. The output of the heater unit 1 increases when the thickness T is decreased.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: November 3, 1998
    Assignee: Denso Corporation
    Inventors: Yasuhiro Oya, Keiichi Yamada, Yosinori Akiyama, Yasuaki Tsujimura
  • Patent number: 5831510
    Abstract: Laminar electrical devices, in particular circuit protection devices, contain two laminar electrodes, with a PTC element between them, and a cross-conductor which passes through the thickness of the device and contacts one only of the two electrodes. This permits connection to both electrodes from the same side of the device. The device also includes layers of solder on the areas of the device through which connection is made, and separation and/or masking members which (a) reduce the danger of short circuits formed by solder flow during installation of the device and/or (b) provide a site for permanent marking of the device.
    Type: Grant
    Filed: September 24, 1996
    Date of Patent: November 3, 1998
    Inventors: Michael Zhang, Shou-Mean Fang
  • Patent number: 5831512
    Abstract: A resistance thermometer has a measuring resistor in the form of a resistance layer essentially made of a metal of the platinum group, preferably of platinum, laid on an electrically insulating surface of a carrier having a thermal expansion coefficient in the range 8.5 to 10.5 ppm/K range, and is provided with an electrically insulating cover layer. The carrier for the resistance layer can be constructed in the following manner: (a) as a substrate of a material containing a magnesium compound, preferably magnesium titanate; (b) as an intermediate layer mounted on a substrate, wherein the material of the substrate contains at least one magnesium compound; or (c) as an intermediate layer mounted on a substrate, wherein the substrate comprises aluminum oxide. With the resistance thermometer it is possible to attain a high long-term stability in the upper temperature range (above 500.degree. C.).
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: November 3, 1998
    Assignee: Heraeus Sensor-Nite GmbH
    Inventors: Karlheinz Wienand, Stefan Dietmann, Eva Soll
  • Patent number: 5820995
    Abstract: A laminated composite ceramic is formed with a positive temperature coefficient (PTC) ceramic element and either a negative temperature coefficient (NTC) ceramic element or a fixed resistance ceramic element, laminated and integrated with each other as a laminated ceramic body. An inner electrode is at least on the boundary between these ceramic elements. These elements have barium titanate as main constituents. A laminated composite ceramic element has similar ceramic elements with inner electrodes buried in parts and connected to outer electrodes formed on different side surfaces of the ceramic body. The molar % of barium and titanate Ba/Ti is preferably 0.99-1.05 for the PTC ceramic element and 0.95-1.01 for the NTC and fixed resistance ceramic elements.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: October 13, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Hideaki Niimi
  • Patent number: 5818676
    Abstract: A self-resetting circuit overcurrent protection device comprises two or more flat positive temperature coefficient (PTC) elements, each comprising a layer of PTC material sandwiched between two metal plates, disposed in a parallel, overlapping configuration and connected in electrical parallel. The resulting circuit protection device has a hold current equal to the sum of the hold currents of the component PTC elements, while having a surface area no greater than that of a PTC device comprising only one of the component PTC elements. In the preferred embodiment of the invention, two PTC elements are used and one of the metal plates belonging to each of the PTC elements has a blade terminal integrally formed therewith, the terminals being substantially identical in configuration to the terminals of a standard automotive fuse which the device is intended to replace.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: October 6, 1998
    Assignee: Yazaki Corporation
    Inventor: William Gronowicz, Jr.
  • Patent number: 5815063
    Abstract: A positive temperature coefficient thermistor formed of a principal ingredient comprising barium titanate, lead titanate and calcium titanate, and rare earth elements, being particularly characterized by using calcium titanate as a raw material and having the particle diameter of said calcium titanate among raw material powders made smaller than that of other raw materials. The positive temperature coefficient thermistor formed by the present invention has improved durability in a reducing atmosphere due an increased density of the crystal structure.
    Type: Grant
    Filed: October 10, 1996
    Date of Patent: September 29, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasushi Goto, Eiichi Koga, Takuoki Hata
  • Patent number: 5814791
    Abstract: An electrical assembly (10) comprising a first electrical device (12) comprised of a non-linear resistant, temperature responsive element (14) and first and second electrodes (16,18), the device (12) being connectable to a first power supply (20) such that a first electrical current (i.sub.1) travels through the resistive element (14) from the first electrode (16) to the second electrode (18). A second electrical circuit (24) is in electrical contact with the electrical device (12) such that the second circuit (24) may introduce a secondary electrical current (i.sub.2) into a localized portion of the non-linear resistant element (14), the second current (i.sub.2), when applied to the non-linear resistant element (14), causes the element (14) to change from a first resistant state to a second resistant state.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: September 29, 1998
    Assignee: Littelfuse, Inc.
    Inventor: Wallace C. Rudd
  • Patent number: 5808538
    Abstract: An electrical apparatus comprising first and second PTC elements composed of a polymer composition with conductive particles dispersed therein, an insulating body, and first and second conductive terminals. Flexible conductive members having a first end that can be electrically connected to a source of electrical power and a second end that is adapted to receive and make electrical contact with the apparatus are provided. The PTC element and the insulating body are positioned between the first and second conductive terminals so that when the apparatus is inserted between the flexible conductive members, the members exert a pressure on the insulating body.
    Type: Grant
    Filed: June 19, 1996
    Date of Patent: September 15, 1998
    Assignee: Littelfuse, Inc.
    Inventor: Thinh Nguyen
  • Patent number: 5805049
    Abstract: The invention relates to a temperature-measuring-resistor which comprises vanadium oxide as a matrix material. The matrix material further contains at least one member selected from a metal, a metal oxide and a metal nitride, and the member has an electric conductivity higher than that of the vanadium oxide. The temperature-measuring-resistor has a low room temperature resistivity, and a volume resisivity that varies greatly with temperature.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: September 8, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akira Yamada, Takehiko Sato, Toshihisa Honda, Toshio Umemura, Fusaoki Uchikawa
  • Patent number: 5804797
    Abstract: A PTC planar heater according to the present invention is produced by bonding one or a plurality of PTC ceramic sheets, each having a pair of electrodes formed on the surface thereof, to an insulator. The electrode pairs are electrically connected in parallel by lead wires. An insulating elastic layer covers the electrodes to prevent warpage, electrical leaks, and shorting. A thickness of the PTC ceramic sheets equal to or greater than 0.5 mm prevents warpage. Resistance is adjusted by cutting conductive paths in the electrodes or by connecting predetermined portions of the electrodes. Further, in a PTC planar unit according to the present invention, a PTC thermistor element having a pair of electrodes formed thereon is in direct contact with one side of an insulation substrate, and a insulation substrate is mounted to the other side thereof.
    Type: Grant
    Filed: September 18, 1995
    Date of Patent: September 8, 1998
    Assignee: Nippon Tungsten Co., Ltd.
    Inventors: Takashi Kaimoto, Osamu Nakano, Masanori Saito, Koichi Inenaga
  • Patent number: 5801612
    Abstract: A circuit protection device for protecting batteries is formed from a resistive element composed of a PTC conductive polymer composition and two electrodes. The device has a resistive element thickness of 0.025 to 0.20 mm; a crosslinking level equivalent to 1 to 20 Mrads; a surface area of at most 120 mm.sup.2 ; a resistance at 20.degree. C., R.sub.20, of at most 0.030 ohm; and a resistivity at 20.degree. C., .rho..sub.20, of at most 2.0 ohm-cm. Devices of the invention are sufficiently small to be easily inserted into an assembly comprising a battery, particularly a rechargeable battery, and the device. Such assemblies are used for powering portable electronic equipment such as cellular telephones.
    Type: Grant
    Filed: August 13, 1997
    Date of Patent: September 1, 1998
    Assignee: Raychem Corporation
    Inventors: Daniel A. Chandler, Luis A. Navarro, Edward F. Chu
  • Patent number: 5798685
    Abstract: A positive-characteristics thermistor apparatus has an insulating case, positive-characteristics thermistor devices, planar terminals, and spring terminals. Whichever thermistor device has a lower resistance of the two thermistor devices is trimmed to have a higher resistance which is near the resistance of the other thermistor device such that the two thermistor devices have substantially the same resistance (for example, within a difference of .+-.1.OMEGA.). In other words, a part of an electrode of the thermistor device having a lower resistance is removed with a laser beam.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: August 25, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takayo Katsuki, Takashi Shikama
  • Patent number: 5798684
    Abstract: A thin-film temperature sensor with a robust bridge structure and a stable electric characteristic, as well as a method of manufacture thereof, is provided. Over the substrate 1 with the cavity 13 are formed electrode layers 6 in a bridge shape, whose electrodes 6A, 6B are bonded with thermal sensitive resistor films 7, 8, which are then covered with a protective insulating film 9, a buffer film 10 and a glass layer 11 in that order. The protective insulating film 9 and the glass layer 11 extend over the substrate 1 to increase the mechanical strength of the infrared sensitive element A. The sandwich structure of the insulating films 5, 9 holding the thermal sensitive resistor films 7, 8 in between and the use of the buffer film 10 combine to prevent electrical characteristic variations, which would otherwise be caused by changes in composition of the thermal sensitive resistor films 7, 8 during the heat treatment process.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: August 25, 1998
    Assignee: Ishizuka Electronics Corporation
    Inventors: Haruyuki Endo, Takeshi Fuse, Hiroyuki Ishida
  • Patent number: 5796568
    Abstract: A reversible short circuit current limiter which has at least one PTC thermistor connected in parallel with a shunt impedance branch, and is connected in series with at least one capacitor or a capacitor bank of the DC intermediate circuit. The short circuit current limiter may be arranged in the DC intermediate circuit or in the current convertor. A diode may be connected in the reverse-bias direction of a short circuit path in parallel with the PTC thermistor. The shunt impedance branch has a varistor connected in series with an ohmic resistor or a PTC thermistor and, if appropriate, an inductor. Structures of metal-based nonblocking PTC thermistors are specified.
    Type: Grant
    Filed: March 20, 1997
    Date of Patent: August 18, 1998
    Assignee: Asea Brown Boveri AG
    Inventor: Tudor Baiatu
  • Patent number: 5796569
    Abstract: A self-resetting circuit overcurrent protection device suitable for use as a replacement for a conventional cylindrical fuse has at least one semi-tubular positive temperature coefficient (PTC) element surrounded by a tubular, electrically insulating body and connected to terminal caps disposed at either end of the cylinder. In a first embodiment of the invention, first and second PTC elements are disposed such that the concave surfaces thereof are oriented toward one another and are connected in electrical parallel so that the hold current of the PTC device is equal to the sum of the hold current values of each of the two elements. In a second embodiment, a first pair of semi-tubular PTC elements are disposed in nested, concentric relationship to one another and a second pair of semi-tubular PTC elements are disposed in nested, concentric relationship to one another, the two pairs of PTC elements being disposed with concave surfaces thereof facing one another.
    Type: Grant
    Filed: June 19, 1997
    Date of Patent: August 18, 1998
    Assignee: Yazaki Corporation
    Inventor: William Gronowicz, Jr.
  • Patent number: 5793277
    Abstract: A plurality of supporting columns extend downwardly from a top wall of a cover attached to the electrical junction box body. A case surrounding the PTC element has projecting bars extending in the cover attaching direction. Each of the supporting columns has a guide groove receives the associated projecting bar so as to hold the case. The PTC element joints to connecting terminal strips having a heat radiation face. Further, the connecting terminal strip has a saw-tooth face at each side end thereof.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: August 11, 1998
    Assignee: Yazaki Corporation
    Inventors: Yuichiro Ichikawa, Hidenori Yamanashi
  • Patent number: 5793276
    Abstract: An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein the conductive substance is tungsten carbide powder; or the electrodes each comprise a metal mesh and a metal layer.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: August 11, 1998
    Assignee: TDK Corporation
    Inventors: Hisanao Tosaka, Minoru Takaya, Shigeru Moriya, Hisashi Kobuke, Munemitsu Hamada
  • Patent number: 5790011
    Abstract: There is provided a positive characteristics thermistor device having excellent thermal breakdown characteristics. According to the present invention, a positive characteristics thermistor device has a positive characteristics thermistor element 1 and electrodes 2 and 3 formed on principal surfaces of the positive characteristics thermistor element 1. The positive characteristics thermistor element 1 includes an inner region 4 and outer regions 5 and 6 and a porosity occupying rate of the outer regions 5 and 6 is set higher than that of the inner region 4.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: August 4, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Atsushi Hirano, Shigeyuki Kuroda, Kenji Tanaka
  • Patent number: 5781098
    Abstract: A temperature sensor includes a temperature sensing section having a thermistor element 11 and connecting ends 121 and 122, an outside connection circuit having detecting resistors 211 to 213 and connecting ends 221 to 225, and a switching element 30 for obtaining a selective connection between the first ends 121 and 122 and the second ends 221 to 225. The switching element 30 is for example constructed by a connector 31 and a shunt wire 32. The second switching element 30 can, as an alternative, be constructed by a pair of connectors, which provide different mutual positions, one of which is selected to obtain a connection. As a second feature, a connector, which is separate from the thermistor element, is provided with adjusting resistors which are in series and in parallel connected to the thermistor element.
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: July 14, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventor: Masamichi Shibata
  • Patent number: 5777541
    Abstract: A two-terminal resistor (2) having a positive temperature coefficient of resistivity, comprised of a plurality of disc-shaped resistive elements (1) which are arranged and held together in a stack, whereby: each resistive element (1) has two oppositely-situated principal surfaces (3), each of which is metallised substantially in its entirety; a metallic arm (7) is situated between each pair of adjacent resistive elements (1), and is soldered to a principal surface (3) of each element (1) in the pair; a metallic arm (7') is soldered to the terminating principal surface (3') at each end of the stack; part of each metallic arm (7, 7') protrudes outward beyond the boundary of the stack; the protruding parts of the metallic arms (7, 7') with an even ordinal (n=2,4,6) are rigidly connected to a first terminal (9a), and the protruding parts of the metallic arms (7, 7') with an odd ordinal (n=1,2,3) are rigidly connected to the second terminal (9b).
    Type: Grant
    Filed: August 5, 1996
    Date of Patent: July 7, 1998
    Assignee: U.S. Philips Corporation
    Inventor: Guy O. A. Vekeman
  • Patent number: 5767485
    Abstract: A sheathed heater comprises a heater disposed in a sheath tube by way of an insulation powder and is connected in series with a heat resistor and a current regulation resistor. The current regulation resistor is made from a cobalt-copper alloy which contains a copper component in the range from 1.0% to 14% by weight.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: June 16, 1998
    Assignee: NGK Spark Plug Co., Ltd.
    Inventor: Chiaki Kumada
  • Patent number: 5764129
    Abstract: A ceramic resistor includes zinc oxide as a main component, and as essential components, aluminum oxide 3.0-40 mol %, magnesium oxide 2.0-40 mol %, silicon oxide 0.1-10 mol %, and at least one kind of compound 0.005-0.5 mol %, selected from a group consisting of calcium oxide, strontium oxide and barium oxide, and has a positive temperature coefficient of resistance. A neutral grounding resistor and a gas circuit breaker, each using the above-mentioned ceramic resistors, are disclosed.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: June 9, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Moritaka Syouji, Tadashi Kitami, Seiichi Yamada, Ken Takahashi, Shingo Shirakawa, Takeo Yamazaki, Shigeru Tanaka, Shigehisa Motowaki
  • Patent number: 5764130
    Abstract: A temperature sensing element packaged in a protected basket by a single insert molding operation. This design does not obstruct the air flow perpendicular to the thermistor thickness, and thus provides enhanced response time.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: June 9, 1998
    Assignee: General Motors Corporation
    Inventors: Peter John Straub, Richard Darrell Kirkwood
  • Patent number: 5764470
    Abstract: A rush current suppression circuit suppresses a peak value of a rush current flowing into a heater. The rush current suppression circuit includes a parallel circuit formed by a positive-characteristic thermistor and a negative-characteristic thermistor. The negative-characteristic thermistor has a resistance at a normal temperature higher than that of the positive-characteristics thermistor. The parallel circuit is connected in series to the heater.
    Type: Grant
    Filed: December 4, 1996
    Date of Patent: June 9, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Kenjiro Mihara, Hideaki Niimi, Yuichi Takaoka
  • Patent number: 5763929
    Abstract: A transistor package includes a power bipolar transistor chip having a thermistor on and electrically connected to a bipolar transistor collector electrode. The thermistor exhibits a positive thermal coefficient (PTC) resistance characteristic and is series connected to the transistor collector. Collector current is interrupted by thermistor response to heat generated during excess transistor collector current events to thereby avoid thermal destruction of the device.
    Type: Grant
    Filed: June 16, 1997
    Date of Patent: June 9, 1998
    Assignee: Kabushiki Kaisha Tokai Rika Denki Seisakusho
    Inventor: Hitoshi Iwata
  • Patent number: 5760676
    Abstract: In a positive temperature coefficient thermistor, a terminal holding member is provided between an outer casing and an elastic terminal electrically connected to the semiconductor ceramic element. The terminal holding member is formed of a thermoplastic resin having a low softening point. Consequently, when an abnormally large amount of heat is generated in the semiconductor ceramic element, the terminal holding member melts and deforms, causing the semiconductor ceramic element to be separated and thereby electrically disconnected from the terminal.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: June 2, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Yoshihiro Yamada
  • Patent number: 5760336
    Abstract: A circuit package for a varistor chip includes a housing made of an electrical insulating and burn-resistant composition. The housing includes a surrounding wall with upright front and rear wall portions and opposite side wall portions which interconnect the front and rear wall portions and which have lower sections that are formed with aligned pairs of wire holes, and a bottom wall connected to a bottom end of the surrounding wall. Each of two electrical contact pieces is disposed inside the housing and is located adjacent to a respective one of the front and rear wall portions of the surrounding wall. The contact pieces receive the varistor chip therebetween and are provided with contact portions that abut against the varistor chip. Each of the contact pieces has opposite sides formed with a pair of contact tabs. Each of the contact tabs is juxtaposed with a respective one of the wire holes and is used to establish external electrical connection with the varistor chip.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: June 2, 1998
    Inventor: Jack Wang
  • Patent number: 5742223
    Abstract: An electrical device in which a first resistive element which is composed of a first electrically non-linear composition is in electrical contact, and preferably in physical and electrical contact, with a second resistive element which is composed of a second composition which has a resistivity of less than 100 ohm-cm. The first composition has a resistivity of more than 10.sup.9 ohm-cm and contains a first particulate filler. The second composition contains a second particulate filler which (a) is magnetic and electrically conductive, and (b) is aligned in discrete regions in the second polymeric component. The device also contains first and second electrodes which are positioned so that current can flow between the electrodes through the first and second resistive elements. Devices of the invention have relatively low breakdown voltages and can survive high energy fault conditions.
    Type: Grant
    Filed: December 7, 1995
    Date of Patent: April 21, 1998
    Assignee: Raychem Corporation
    Inventors: William H. Simendinger, III, Charles A. Boyer, Rudolf R. Bukovnik
  • Patent number: 5734314
    Abstract: A surge resistor has a thick film resistance element containing alloyed nickel-chromium mixed with alloyed copper-nickel and less than twenty percent by weight glass. The surge resistor overcomes the limitations of the prior art by offering the unexpected advantage of improved power surge handling capacity. A thick film composition used to form the surge resistor, which also includes screening agent, is fired at temperatures generally below 1,000.degree. C., yielding a highly stable and well adhered electrical resistor. In addition to improved surge capability, the composition offers lower cost and less migration than the precious metal alternatives that the composition replaces. Additional inventive surge resistors include copper-manganese and nickel-chromium in combination with less than twenty percent by weight glass.
    Type: Grant
    Filed: August 8, 1996
    Date of Patent: March 31, 1998
    Assignee: CTS Corporation
    Inventor: Charles C. Y. Kuo
  • Patent number: 5726623
    Abstract: A temperature dependent resistive component (10) has two supports (12, 14) attached to its respective opposite faces, each support having at least one projecting leg which terminates in a contact pad (13 or 14), the contact pads of the two supports (12, 14) lying in a common plane spaced from the component (10), for mounting the component to a substrate. Each support may comprise a wire bonded to the respective face of the component, or a piece of sheet material bent to channel-section and bonded via its edges to the face of the component. The common plane, in which the contact pads lie, may be parallel to but spaced from one face of the component, or perpendicular to the opposite faces of the component and spaced from its edge.
    Type: Grant
    Filed: August 26, 1996
    Date of Patent: March 10, 1998
    Assignee: Bowthorpe Components Limited
    Inventor: Philip George Camp
  • Patent number: 5721043
    Abstract: The invention described is an improved dielectric material formed as a film on the surface of a substrate by adding lead to an original perovskite material having an original critical grain size to form a lead enhanced perovskite material, then forming a layer of the lead enhanced perovskite material having an average grain size less than the original critical grain size whereby the dielectric constant of the layer is substantially greater than the dielectric constant of the original perovskite material with an average grain size similar to the average grain size of the layer. The critical grain size, as used herein, means the largest grain size such that the dielectric constant starts to rapidly decrease with decreasing grain sizes. Preferably, the lead enhanced perovskite material is further doped with one or more acceptor dopants whereby the resistivity is substantially increased and/or the loss tangent is substantially decreased. Preferably, the original perovskite material has a chemical composition ABO.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 24, 1998
    Assignee: Texas Instruments Incorporated
    Inventors: Scott R. Summerfelt, Howard R. Beratan, Bernard M. Kulwicki
  • Patent number: 5721525
    Abstract: A temperature controller (10) having bimetallic switching device (15) which switches at an excess temperature and a heating resistor (23) in the same circuit as this which has the effect of a self-locking function. The heating resistor (23) is designed on a film (22) which is provided for thermal and/or electrical insulation.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: February 24, 1998
    Inventor: Marcel Hofsass
  • Patent number: 5714924
    Abstract: The internal space of the case is divided into first housing portions and a second housing portion separated from the first housing portions by a partitioning wall. A positive characteristic thermistor element is housed in the second housing portion. At least two terminal members are provided, each with a contact terminal portion, a conductive portion and a lead-out terminal portion. The contact terminal portions are positioned in the second housing portion each in contact with one of the electrodes of the positive characteristic thermistor element. The conductive portions are electrically continuous to the contact terminal portions and are led to the first housing portions through the partitioning wall. The lead-out terminal portions positioned in the first housing portions, are electrically connected to the conductive portions and led out to the outside at the first housing portions.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: February 3, 1998
    Assignee: TDK Corporation
    Inventors: Michikazu Takeuchi, Kazuo Saito
  • Patent number: 5699607
    Abstract: An electrical device comprising a resistive element having a first electrode in electrical contact with the top surface of the resistive element and a second electrode in electrical contact with the bottom surface of the resistive element. An insulating layer is formed on the first and second electrodes. A portion of the insulating layer is removed from the first and second electrodes to form first and second contact points. A conductive layer is formed on the insulating layer and makes electrical contact with the first and second electrodes at the contact points. The conductive layer has portions removed to form first and second end terminations separated by electrically non-conductive gaps. The wrap-around configuration of the device allows for an electrical connection to be made to both electrodes from the same side of the electrical device.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: December 23, 1997
    Assignee: Littelfuse, Inc.
    Inventors: Katherine M. McGuire, Mike A. Ward
  • Patent number: 5694107
    Abstract: An oxide composition including (A1.sub.1-x-y Cr.sub.x Fe.sub.y).sub.2 O.sub.3 and prescribed amounts of Mn or Mg, is provided. A temperature sensor including a heat-resistant cap, a thermistor element accommodated in the heat-resistant cap, and a pair of lead wires electrically connected to each other via the thermistor element and extending outside the heat-resistant cap is also provided, the thermistor element including the above-mentioned oxide composition.
    Type: Grant
    Filed: April 22, 1996
    Date of Patent: December 2, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroki Moriwake, Tsuyoshi Tanaka, Masayuki Takahashi
  • Patent number: 5691688
    Abstract: A PTC device having a PTC material sandwiched between a pair of metal plates includes a plurality of spaced-apart legs extending outwardly from the plates for reception in circuit board slots. Certain legs terminate in transverse hook portions for retaining same in a circuit board slot.
    Type: Grant
    Filed: July 20, 1994
    Date of Patent: November 25, 1997
    Assignee: Therm-O-Disc, Incorporated
    Inventors: Jeffrey A. West, Robert L. Newman
  • Patent number: 5691689
    Abstract: Electrical circuit protection devices containing PTC elements comprised of conductive polymers which exhibit PTC behavior and are used to protect a load in an electrical circuit, in which the PTC conductive polymers are based on highly crystalline and highly ordered liquid crystal polymers and particulate conductive fillers dispersed therein, which are cross-linked by radiation. These circuit protection devices operate as automatically resettable current limiters and are particularly useful for protecting motors, solenoids, telephone lines and batteries, and for enhancing circuit interruption capability when used in conjunction with breakers and contactors. The liquid crystal polymers include aromatic polyesters, e.g., poly(p-phenylene terephthalate) and poly(p-hydroxybenzoate); aromatic copolyesters, e.g., poly(p-hydroxybenzoate-co-2,6-hydroxynaphthoate), poly(deca-methyleneterephthaloyl di-p-hydroxybenzoate, and poly(ethylene terephthalate-co-oxybenzoate); aromatic copolyester amides, e.g.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: November 25, 1997
    Assignee: Eaton Corporation
    Inventors: James D. B. Smith, Karl F. Schoch, Jr., Selami Y. Pusatcioglu, Xiaoyun Shirley Lai
  • Patent number: 5688424
    Abstract: A PTC thermistor comprising a ceramic body having positive temperature coefficient resistivity, a pair of electrode layers provided on both major surfaces of the ceramic body so as to be opposed to each other with the ceramic body interposed therebetween, a pair of metal terminals electrically connected to the electrode layers, and a resin molded portion provided so as to cover side surfaces of the ceramic body and side surfaces of the electrode layers, the metal terminal having a connecting plate electrically connected to the electrode layer and a terminal plate opposed to the connecting plate so that a space is formed between the terminal plate and the connecting plate and connected to the connecting plate by a linking portion, and the resin molded portion being so formed as to expose an outer side surface of the terminal plate of the metal terminal and fill the space between the connecting plate and the terminal plate of the metal terminal.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: November 18, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Shyoji Asida
  • Patent number: 5681111
    Abstract: A method and apparatus for determining the temperature of an environment at an elevated temperature (i.e., one exceeding about 300.degree. C.) wherein oxides that do not melt at such temperatures, do not age significantly at such temperatures and which have a sensitivity for such measurements are employed as thermistor resistors. Such oxides are calcium zirconate, yttria, alumina, dysprosia, magnesia, the oxide combinations alumina-silica, zirconia-silica and titania-silica. Measurements in electric current change is preferably the measurement of alternating current rather than the conventional dc current. A particularly useful instrument for such measurements consists of such a resistor with a laminate of connector metal such as diffusion bonded precious metal sheets or foils on separated surface areas as electrode connectors.
    Type: Grant
    Filed: June 17, 1994
    Date of Patent: October 28, 1997
    Assignee: The Ohio State University Research Foundation
    Inventors: Sheikh A. Akbar, Weihua Chen, Virginia D. Patton, Ching C. Wang
  • Patent number: 5682130
    Abstract: The invention is a circuit protection device comprising a first and a second female terminal. The device further comprises a first fuse clip in electrical contact with the first fuse terminal and a second fuse clip in electrical contact with the second fuse terminal. A positive temperature coefficient element, preferably planar, is positioned between and makes electrical contact with both the first fuse clip and the second fuse clip. In a first embodiment, at least one of the first and second fuse clips is spring-loaded, i.e., has an inherent resiliency. In this same embodiment, portions of the first and second fuse clips overlap, and the positive temperature coefficient element is secured between the overlapping portions of the first and second fuse clips. In the second of the two preferred embodiments, the first fuse clip, the second fuse clip, and the positive temperature coefficient element are generally coplanar.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 28, 1997
    Inventors: Michael Styrna, Andrew Tomlinson
  • Patent number: 5677662
    Abstract: A heat-sensitive resistive compound is formed by a mixture of particles of at least one electrically conducting material (A) in the solid state and of at least one resin (B) in the solid state; the mixture is dispersed in at least one liquid solvent (C); the percentage by weight of the electrically conducting material (A) with respect to the total weight of the anhydrous compound is 5% to 70%. The resistance of the compound after a furnace process increases, as the temperatures rises, in a substantially linear manner for temperatures that are approximately lower than or equal to 70.degree. C. and in a substantially exponential manner for temperatures that are approximately higher than 70.degree. C. The relative increase in the resistance of the compound with respect to its resistance at ambient temperature is at least 3 for temperatures higher than 100.degree. C. and at least 5 for temperatures above 115.degree. C.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: October 14, 1997
    Assignee: Hydor S.R.L.
    Inventors: Valerio Bresolin, Daniele Ragazzon
  • Patent number: 5663702
    Abstract: Electrical devices with a PTC element including a polymer having conductive particles dispersed therein and at least one metallized ceramic electrode. The devices are made by dispersing conductive particles into a polymer to form a polymer PTC composition. The metallized ceramic electrodes include a ceramic substrate having a conductive layer deposited on its surface. The metallized ceramic electrodes are brought into contact with the PTC element, and heated while applying pressure to form a laminate. The laminate is then diced into a plurality of PTC electrical circuit protection devices.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: September 2, 1997
    Assignee: Littelfuse, Inc.
    Inventors: Philip C. Shaw, Jr., Paul Charles Stein
  • Patent number: 5658479
    Abstract: The positive temperature coefficient thermistor heater is composed of a positive temperature coefficient thermistor element, and electrodes formed on the both principal faces of the thermistor element. At least one of the electrodes consists of split electrodes. The positive temperature coefficient thermistor heater device has a positive temperature coefficient thermistor heater in which at least one of the electrodes consists of split electrodes, and radiator plates disposed on the both principal faces of the thermistor element. The split electrodes of the positive temperature coefficient thermistor heater are equal in area to each other, or different from each other.
    Type: Grant
    Filed: November 30, 1994
    Date of Patent: August 19, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Tomoaki Tadokoro
  • Patent number: 5656987
    Abstract: In order to improve uniformity of temperature distribution, despite heat which is generated in a resistance circuit and flows into a support part thereby causing a high output, a resistance circuit is provided with first, second and third regions having different resistance values so that the third region which is in proximity to the support part has the highest resistance value.
    Type: Grant
    Filed: February 15, 1994
    Date of Patent: August 12, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Teppei Kubota, Kazuto Miyagawa, Hiroji Tani, Tohru Kasanami