Thermistor Type Patents (Class 338/22R)
  • Patent number: 5644284
    Abstract: An oxide composition including (Al.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 25, 1995
    Date of Patent: July 1, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroki Moriwake, Tsuyoshi Tanaka, Masayuki Takahashi
  • Patent number: 5644461
    Abstract: A current limiter for protecting a circuit at a predetermined driving voltage in excess of 50 volts which includes a plurality of PTC resistors connected in series, with a zener diode connected in parallel with each of the PTC resistors, and wherein each of the PTC resistors has a predetermined voltage capacity limit such that the total of the predetermined capacity limits of the PTC resistors exceeds the predetermined driving voltage, and each of the zener diodes has a zener voltage rating less than the predetermined voltage capacity limit of the individual PTC resistor connected in parallel therewith, and the total of the zener voltage ratings of the zener diodes also exceed the predetermined driving voltage.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: July 1, 1997
    Assignee: Westinghouse Air Brake Company
    Inventors: Craig A. Miller, Joseph C. Fray
  • Patent number: 5637543
    Abstract: A ceramic composition for thermistor exhibiting stable resistance values over a wide temperature range and capable of being used for a prolonged time. The composition is represented by (M.sup.1 M.sup.2 O.sub.3).sub.1-x .multidot.(M.sup.1 AlO.sub.3).sub.x, wherein M.sup.1 is an element selected from the elements of the group 3A excluding La and M.sup.2 is an element of the groups 4A, 5A, 6A, 7A and 8, and wherein the mixing ratio between an electrically conductive substance stable at elevated temperatures and an insulating substance stable at elevated temperatures, may be adjusted. A thermistor formed of the composition is superior in high-temperature stability and can be used over a broad temperature range because its resistance value can be selected to an optimum value.
    Type: Grant
    Filed: December 18, 1995
    Date of Patent: June 10, 1997
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masaki Iwaya, Kyohei Hayashi, Hiroshi Matsuzaki, Yoshirou Suematsu
  • Patent number: 5619060
    Abstract: A thermal picture synthesis device (1) of multi-layer construction has a resistor element (3) spaced from a semi-conductor substrate layer (2). The resistor element (3) is made of titanium or Ni-chrome. A drive element layer (4) is provided either in or attached to the substrate layer (2) for the resistor element (3). By placing the drive element layer parallel to and spaced from the resistor element (3) it is possible to pack a plurality of resistor elements (3) into a side by side adjacent array with a high fill factor or packing density and this coupled with the use of titanium or Ni-chrome for the resistor elements (3) and the spacing of these elements from the semi-conductor substrate (2) allows the device to operate at a higher apparent temperature than is conventional.
    Type: Grant
    Filed: June 7, 1994
    Date of Patent: April 8, 1997
    Assignee: British Aerospace Public Limited Company
    Inventors: Alan P. Pritchard, Stephen P. Lake, Ian M. Sturland
  • Patent number: 5617281
    Abstract: A circuit controller for selectively connecting a power source to a load includes a switching mechanism, which selectively connects the power source to the load and switches a current which flows through the switching mechanism, and a substantially radiant energy dissipating positive temperature coefficient current limiter for limiting the current which flows through the switching mechanism. The switching mechanism includes a current sensor, which senses the current flowing through the switching mechanism and provides a sensed current value, and a switching controller for disconnecting the power source from the load whenever the sensed current value is above a predetermined current value. The switching mechanism may include a contactor having separable contacts which are responsive to the switching controller. The current limiter may have a first resistance which results from a first series current, and a higher second resistance which results from a second series current.
    Type: Grant
    Filed: June 1, 1994
    Date of Patent: April 1, 1997
    Assignee: Eaton Corporation
    Inventors: James A. Bauer, Nelson R. Palmer, Kathryn M. Palmer, Henry A. Wehrli, III
  • Patent number: 5614881
    Abstract: A current limiting device utilizing an electrically conductive composite material and an inhomogeneous distribution of resistance structure is disclosed. The inhomogeneous distribution is typically chosen so that at least one selected thin layer of the current limiting device has much higher resistance than the rest of the current limiting device. In the actual device, pressure is typically exerted on the composite material in a direction normal to the selected thin layer. During a short-circuit, it is believed that adiabatic resistive heating of this selected thin layer is followed by rapid thermal expansion which leads to either a partial or complete physical separation of the current limiting device at the selected thin layer which produces a higher over-all device resistance to electric current flow. Thus the current limiting device limits the flow of current through the short-circuited current path.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: March 25, 1997
    Assignee: General Electric Company
    Inventors: Anil R. Duggal, Lionel M. Levinson, Harold J. Patchen, Larry N. Lewis
  • Patent number: 5610111
    Abstract: Ceramic composition for thermistor for detecting elevated temperatures which exhibits stable properties at elevated temperatures for permitting use in both oxidizing and reducing atmospheres. In a YCrO.sub.3 based material, Sr or Sm is partly or completely substituted for Y, and Fe and Ti are substituted for part of Cr. Such material enables the production of a thermistor element exhibiting practical, low resistance values at 300.degree. to 1100.degree. C. and also exhibiting stability against changes in the environmental conditions or thermal hysteresis. Generally AMO.sub.3 perovskite structure (A=2A,3A,3B subgroup elements, M=4A,5A,6A,8 subgroup elements) having a combination of n-type and p-type components provides the same property, the subgroup being of IUPAC international periodic table. La-free is preferred and sintering aid may be used.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: March 11, 1997
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masaki Iwaya, Kyohei Hayashi
  • Patent number: 5610571
    Abstract: A thermistor type temperature sensor includes a mounting sheet made of insulating ceramic; a plurality of thermistor elements disposed on the mounting sheet; a detecting device, disposed on the mounting sheet, for electrically conducting with the thermistor elements and detecting changes in the resistance value of the thermistor elements; and a cover sheet for hermetically sealing the thermistor elements and the detecting device by thermocompression-bonding with the mounting sheet.
    Type: Grant
    Filed: February 22, 1995
    Date of Patent: March 11, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventor: Kaoru Kuzuoka
  • Patent number: 5610572
    Abstract: A resistor element has a ceramic substrate and a metallic resistor coated onto the substrate. The metallic resistor has varied electrical resistance depending on temperature. A pair of leads are electrically connected to the metallic resistor. A plurality of glass layers having different compositions are coated onto the metallic resistor. The second glass layer fills a hole formed in the first glass layer, thereby improving response of the resistor element. The second glass layer has a softening point lower than the first glass layer, thereby small bubbles remain dispersed in each glass layer without aggregation. An outermost glass layer is composed of a glass resisting chemicals or a glass resisting abrasion. An innermost glass layer is composed of a glass containing up to 3 percent by mole of a sum of Na.sub.2 O and K.sub.2 O.
    Type: Grant
    Filed: February 23, 1995
    Date of Patent: March 11, 1997
    Assignee: NGK Insulators, Ltd.
    Inventor: Yasuhito Yajima
  • Patent number: 5606302
    Abstract: An electronic component device includes an electronic component element 13 that is interposed between a pair of spring terminals 14 and 15. The electronic component element 13 is resiliently held by the spring terminals 14 and 15, and contact portions 17 and 18 of the spring terminals 14 and 15, which are respectively brought into contact with electrodes 13b and 13c of the electronic component element 13, are positioned on both major surfaces of the electronic component element 13 so as not to be opposed to each other. At least one groove of a set of grooves 16a to 16c is formed on at least one of the major surfaces of the electronic component element 13 for guiding the direction in which the electronic component element 13 is divided when the electronic component element 13 is destroyed by, for example, an abnormal voltage.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: February 25, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Shigehiro Ichida
  • Patent number: 5603572
    Abstract: A temperature sensor for use in a microwave oven includes a metallic housing including a sleeve with a central passage, a metallic top plate coupled to the metallic housing to close off a first end of the central passage, and a temperature dependent resistor sensor element thermally coupled with the metallic plate. The sensor element is coupled to a signal transmission cable that passes through a bottom cap which closes off the other end of the central passage. The transmission cable is preferably connected to the bottom cap by soldering around the entire interface of the cable with the bottom cap. The cable includes at least 90% shielding and plastic insulation sufficient to resist temperatures up to 200 degrees centigrade. The sleeve is preferably filled with an epoxy cement that surrounds the sensor element.
    Type: Grant
    Filed: December 15, 1994
    Date of Patent: February 18, 1997
    Assignee: Eastman Kodak Company
    Inventors: Jacob M. Shmois, Fugui He, Francisco Chiarilli, David E. Foeller, Kenneth D. Corby
  • Patent number: 5602520
    Abstract: The electrical resistance element (10) includes a resistance body (3), which is arranged between two plane-parallel, pressurized electrodes (1, 2), has PTC behavior and comprises a polymer matrix and two filler components of electrically conducting particles embedded into the polymer matrix (4).When a short-circuit current occurs, the resistivity of the resistance body (3) changes abruptly above a temperature limit value in a surface layer resting on the electrodes and containing at least a first of the two filler components. A second of the two filler components is selected such that a composite material containing at least the polymer matrix and the second filler component has PTC behavior, with an abruptly changing behavior greater by at least one order of magnitude in comparison with the surface layer. At the same time, this composite material has a resistivity which is lower by at least one order of magnitude than a composite material formed by the polymer matrix and the first filler component.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: February 11, 1997
    Assignee: ABB Research Ltd.
    Inventors: Tudor Baiatu, Felix Greuter, Ralf Strumpler
  • Patent number: 5600296
    Abstract: A thermistor type temperature sensor having a substrate made from an electrically insulating ceramic plate. A thin or thick film detecting resistor is printed on the substratum. A thick or thin film pull-up resistor may also be printed on the substratum, and trimming of the resistors is possible. The ratio of B-constant values for the detecting resistor and the pull-up resistor may be selected so that it is locate between 0.4 to 0.9 or 1.1 to 1.5. The detecting resistor may be constructed from thermistor sections of the same composition and the sections may be connected in parallel or in series. The thermistor sensor can be connected to the pipe through which a gas passes. When the sensor is connected to the pipe, the angle of the measuring plane may be adjusted, so that a precise measurement can be obtained.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: February 4, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Kaoru Kuzuoka, Sotoo Takahashi, Masamichi Shibata, Susumu Shibayama
  • Patent number: 5592647
    Abstract: A panel heater comprising, on an upper surface of a metallic sheet (2) provided with PTC ceramics (1) on the back side thereof, a highly insulating material or an open space (4) at the portion corresponding to the back side portion to which the PTC ceramics are provided, with a material (3) for conducting heat from the metallic sheet being thus provided to the rest of the surface side of said metallic sheet, and a finishing sheet (5) being established on the upper surface of the whole structure. More preferably, the metallic sheet (2) is provided with equally spaced concave grooves with PTC ceramics (1) on the back plane of said grooves and a highly insulating material or an open space (4) inside said grooves, and a finishing sheet (5) established thereon. Accordingly, a simply structured panel heater resistant to heavy loads yet free from local overheating is provided.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: January 7, 1997
    Assignees: Nippon Tungsten Co., Ltd., Kyushu Electric Power Co., Inc.
    Inventors: Masahiro Yamauchi, Takashi Kaimoto, Mitsuhiko Furukawa, Katsutoshi Rikihisa, Hironori Yoshida, Kenji Watanabe
  • Patent number: 5582757
    Abstract: A sheet-like thermal sensing element includes a carbon fiber mixed paper and resin layers laminated on both surfaces of the carbon fiber mixed paper. Electrodes are provided along opposite two sides of the carbon fiber mixed paper. A temperature change can be detected by detecting the change of resistance value of the carbon fiber mixed paper. A sheet-like heater is also disclosed, the heater including a pair of carbon fiber mixed papers separated by an insulating sheet and surrounded by resin. Each of the carbon fiber mixed papers include electrodes thereon. The sheet like heater can both generate heat and detect temperature change for precise heating control. Also disclosed is a method of making both the sheet-like heater and sheet-like thermal sensing element involving producing the carbon fiber mixed paper, electrode formation, laminating the mixed papers together and resin encapsulation.
    Type: Grant
    Filed: March 18, 1994
    Date of Patent: December 10, 1996
    Assignee: Kabushiki Kaisha Dairin Shoji
    Inventors: Koichiro Kio, Yukiko Hayashi
  • Patent number: 5580493
    Abstract: A conductive polymer composition containing a particulate conductive filler dispersed in a polymeric component. The polymeric component comprises a first polymer which (i) is present in an amount 25 to 75% by weight of the total polymeric component, and (ii) is polyethylene, and a second polymer which (i) is present in an amount 25 to 75% by weight of the total polymeric component, and (ii) comprises units derived from a first monomer which is ethylene and a second monomer which is an alkyl acrylate having the formula --CH.sub.2 .dbd.CHCOOC.sub.m H.sub.2m+1, where m is at least 4. The resulting composition is useful in preparing electrical devices, e.g. circuit protection devices, which have lower resistivities, higher PTC anomalies, and better thermal and electrical stability than devices comprising conventional conductive polymer compositions.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 3, 1996
    Assignee: Raychem Corporation
    Inventors: Edward F. Chu, Nelson H. Thein, Vijay Reddy, Daniel A. Chandler
  • Patent number: 5573004
    Abstract: An apparatus and method for electrically stable electrodes and sensors having a flexible base or substrate. One or more flexible and pressure sensitive resistors having a high resistance and a high temperature coefficient of resistivity are printed on a first surface of the flexible base, and a second set of one or more substantially identical resistors are printed on a second surface such that each resistor on the second surface is directly opposite a resistor on the first surface. The opposing resistors are then electrically interconnected in mating pairs, so that when the substrate is flexed, one resistor of each pair is compressed and the other is tensed with the result that the changes in resistance cancel one another.
    Type: Grant
    Filed: October 6, 1994
    Date of Patent: November 12, 1996
    Assignee: EdenTec Corporation
    Inventor: Allen W. Groenke
  • Patent number: 5568116
    Abstract: A ceramic composition for a thermistor of the formula (M.sup.1.sub.1-x.N.sup.1.sub.x)(P.sup.2.sub.1-y-z.N.sup.2.sub.y.Al.sub.z)O .sub.3 where M.sup.1 is one or more elements selected from the group 3A elements of the Periodic Table excluding La, N.sup.1 is one or more selected from the group 2A elements of the Periodic Table, P.sup.2 is one or more selected from the elements of the groups 4A, 5A, 6A, 7A and 8 of the Periodic Table whose oxides exhibit p-type characteristics, and N.sup.2 is one or more selected from the elements of the groups 4A, 5A, 6A, 7A and 8 whose oxides exhibit n-type characteristics,wherein x, y and z are larger than 0 and smaller than 1 and 0.001.ltoreq.x/(1-y-z)<0.20, 0.05.ltoreq.y/(1-y-z).ltoreq.0.80 and 0<z/(1-y-z).ltoreq.0.90. Thermistor elements are usable within a broad temperature range of 300.degree.-1100.degree. C., have a stable resistance in oxidizing and reducing atmospheres, can prevent deterioration of lead wires, and have superior stability at high temperatures.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: October 22, 1996
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masaki Iwaya, Kyohei Hayashi, Hiroshi Matsuzaki, Yoshirou Suematsu
  • Patent number: 5557251
    Abstract: A thermistor includes a plate-like thermistor body and a first and a second electrode formed on each of the main surfaces of said plate-like thermistor body. The first electrode is formed so that its outer periphery reaches the outer peripheral edge of the thermistor and the second electrode is formed to extend from the area encircled by said first electrode onto the first electrode but not reach the outer periphery of the first electrode. The first and second electrodes are made of material which can make an ohmic-contact with the main surface of said thermistor body. The first electrode is made of the material which is hard to generate inter-electrode migration and said second electrode is made of the material which is easy to generate the inter-migration compared with the first electrode. Thus, the thermistor can prevent short-circuiting due to inter-electrode migration without deteriorating the characteristic such as a current capacity.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: September 17, 1996
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Yuichi Takaoka
  • Patent number: 5555246
    Abstract: A balanced wire resistor has two interconnected windings with different temperature coefficients. The electrical resistance of the wire resistor is determined only by the resistance values of the two windings. In a process for the production of the wire resistor, the wire length of a first winding of the newly to be wound wire resistance is calculated by using the measured wire length, as well as measured resistance values of the previously wound wire resistor. The wire length of a second winding of the newly to be wound wire resistance is determined by using the two measured wire lengths of the two windings, as well as measured resistance values of the previously wound wire resistor.
    Type: Grant
    Filed: February 9, 1994
    Date of Patent: September 10, 1996
    Assignee: Landis & Gyr Business Support AG
    Inventors: David Weber, Willi Wild
  • Patent number: 5550526
    Abstract: The present invention provides thermal detection elements having a controlled relationship between a thermal radiating and thermal sensing element. The thermal detection element includes an insulating substrate having a plurality of conductive interconnection elements formed on the substrate to permit electrical connection of the substrate with other electrical components. A thermal radiating element is at least partially embedded within the substrate and mounted such it electrically communicates with at least one of the conductive interconnection elements. A thermal sensing element is mounted adjacent the thermal radiating element such that a substantial portion of the thermal energy radiated by the thermal radiating element is channeled to the thermal sensing element. The thermal sensing element is also mounted such that it electrically communicates with at least one of the conductive interconnection elements.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: August 27, 1996
    Assignee: Lucent Technologies Inc.
    Inventor: Behzad D. Mottahed
  • Patent number: 5541389
    Abstract: Positive temperature coefficient thermistor is prepared from a sintered body of a ceramic material composition which has as a substrate BaTiO.sub.3 with metallic oxide. There is almost no difference of exothermic temperature even if different voltage is applied to the positive temperature coefficient thermistors. Thus, when the present invention is used in countries or areas in which both 110 V and 220 V of commercial voltages are used, almost certain temperature can be obtained without changing voltage by a transformer.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: July 30, 1996
    Assignee: Ohizumi MFG. Co., Ltd.
    Inventor: Hitoshi Kaneko
  • Patent number: 5535614
    Abstract: A gas sensor of the thermal conductivity type suitable for the quantitative analysis of the fuel vapor content of a fuel-air mixture. The gas sensor (10) comprises a sensing element (28) and a compensating element (30), each of which includes an electrically-heated hot member (38) incorporated into a Wheatstone bridge circuit powered by a constant current supply circuit (70). The constant current supply circuit (70) is adjusted and regulated such that the hot member (38) of the sensing element (28) is heated with an electric current of such an intensity that corresponds to a point of transition (Y) at which, at the interface of the hot member (38) and the mixture, the predominant mode of heat transfer changes from thermal conduction to natural convection.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: July 16, 1996
    Assignee: NOK Corporation
    Inventors: Eiji Okamoto, Kuniaki Miyake
  • Patent number: 5536449
    Abstract: A sintering ceramic for stable high-temperature thermistors includes a system of matter containing manganese (IV) and a content of a basic oxide. A method for producing a sintering ceramic for stable high-temperature thermistors includes calcining a mixture of SrCO.sub.3 and Mn.sub.2 O.sub.3 or Mn.sub.3 O.sub.4 ; adding an oxide hydroxide of a dopant in a molar quantity x to an aqueous suspension of the calcined oxide mixture; and then carrying out a compacting densification of the system of matter.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: July 16, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventors: Adalbert Feltz, Ralph Kriegel, Franz Schrank
  • Patent number: 5534843
    Abstract: An insulating glass layer covers the surface of a thermistor element except at the two end surfaces. The insulating glass layer is partially or fully composed of crystallized glass. A terminal electrode is integrally formed on both end surfaces. The terminal electrodes include a baked-on electrode layer formed from a conductive paste. Layers of nickel and tin or lead/tin are plated onto the baked-on electrode. The insulating glass layer enhances shape-maintainability of the insulating glass layer and the baked-on electrodes, provides a smoother glass surface, resulting in a more aesthetically pleasing thermistor, prevents resistance variance due to plating of the baked-on electrodes and provides a strong anti-breaking strength thermistor. The coefficient of thermal expansion of the glass layer is less than the coefficient of thermal expansion of the thermistor element. This difference in coefficients of thermal expansion tends to help the thermistor element resist stress breakage.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: July 9, 1996
    Assignee: Mitsubishi Materials Corporation
    Inventors: Masakiyo Tsunoda, Hiroaki Nakajima, Masami Koshimura
  • Patent number: 5519374
    Abstract: A hybrid thermistor temperature sensor includes a two-pole network of temperature-dependent resistors being in thermal and electrical contact with each other. The two-pole network has at least one temperature-dependent resistor with a positive temperature coefficient as a cold conductor, at least one temperature-dependent resistor with a negative temperature coefficient as a hot conductor, a temperature/resistance curve with a constant behavior or plateau in a predetermined temperature region, and at least one electrode electrically coupling at least two of the temperature-dependent resistors to each other. The at least one electrode is produced from a material ensuring a contact between the temperature-dependent resistors that breaks down a barrier layer and forms a diffusion barrier to a mutual diffusion of ingredients of each respective one of the contacting temperature-dependent resistors into the other of the temperature-dependent resistors.
    Type: Grant
    Filed: August 26, 1994
    Date of Patent: May 21, 1996
    Assignee: Siemens Matsushita Components GmbH & Co., KG
    Inventors: Franz Schrank, Gerald Kloiber
  • Patent number: 5500996
    Abstract: In a method for manufacturing a thermistor having a negative temperature coefficient in multi-layer technology, a plurality of layers are produced of ceramic material by producing a suspension and then drawing out with a stripping technique to form an extremely thin film from which the individual ceramic material layers are formed. By a silk screening technique, metal coats are applied onto the ceramic metal layers, the metal coats containing at least one precious metal as a critical constituent selected from the group consisting of Hg, Au, Pd, and Pt. The metal layers extend from one side edge of the ceramic layer over the ceramic layer and stop short of and are spaced from the opposite side edge. The ceramic layers are stacked on top of one another, but with an alternating offset of the metal coats. A solderable metallization is applied at sides of the stack and is connected to every other coat at the respective sides.
    Type: Grant
    Filed: February 22, 1993
    Date of Patent: March 26, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventors: Georg Fritsch, Hans G. Schuster
  • Patent number: 5493266
    Abstract: A plurality of semiconductor substrates having positive resistance-temperature coefficients are bonded to each other through a glass layer to be stacked. First and second terminal electrodes are formed on end surfaces of such a stacked structure respectively. First and second ohmic electrodes are formed on respective major surfaces of each semiconductor substrate, and the first and second ohmic electrodes are connected to the first and second terminal electrodes respectively. The ohmic electrodes contain a metal, other than silver, exhibiting an ohmic property, such as zinc, aluminum, nickel or chromium, for example. The terminal electrodes also contain a metal, other than silver, exhibiting an ohmic property. The terminal electrodes may be provided on surfaces thereof with layers which are made of a metal having excellent solderability.
    Type: Grant
    Filed: April 18, 1994
    Date of Patent: February 20, 1996
    Inventors: Kiyomi Sasaki, Hideaki Niimi
  • Patent number: 5488348
    Abstract: A PTC thermistor including ceramic body having a positive temperature coefficient of 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 ceramic reinforcing plate provided on at least one of the major surfaces of the ceramic body, and an output electrode having a connecting portion for making electrical connection with the electrode layer on an inner major surface of the ceramic reinforcing plate and extending to an outer major surface of the reinforcing plate from the connecting portion.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: January 30, 1996
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Shyoji Asida, Haruo Takahata, Takayo Katsuki
  • Patent number: 5481240
    Abstract: A low-cost and compact thermistor-type temperature sensor which has a thermo unit and a metal tube solidly fixed by cement. The sensor has an enlarged reserve space between the thermo unit and the metal tube to accommodate an excess amount of the cement therein, so that intrusion of the cement into electrical connection portions of lead wires is prevented. This enlarged space assures good electrical insulation between the electrical connection portions and stable measurement characteristics.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: January 2, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventors: Matuo Fukaya, Junichi Nagai, Kaoru Kuzuoka
  • Patent number: 5477076
    Abstract: An integrated circuit implements an on chip thermal circuit (12) for measuring temperature of an operating integrated circuit die (10) by requiring only one dedicated integrated circuit pin (16). A second integrated circuit pin (18) is utilized but is also connected directly connected to other circuitry (14) on the integrated circuit and is used by the other circuitry at the same time that the integrated circuit die temperature is being measured. In one form, the second integrated circuit pin is a ground terminal. Error voltages coupled to the ground terminal may be removed from the temperature calculation by an external differential amplifier (24).
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: December 19, 1995
    Assignee: Motorola, Inc.
    Inventors: James G. Gay, William B. Ledbetter, Jr.
  • Patent number: 5476822
    Abstract: A ceramic composition for thermistor exhibiting stable resistance values over a wide temperature range and capable of being used for a prolonged time. The composition is represented by (M.sup.1 M.sup.2 O.sub.3).sub.1-x .multidot.(M.sup.1 AlO.sub.3).sub.x, wherein M.sup.1 is an element selected from the elements of the group 3A of the International Periodic Table excluding La and M.sup.2 is an element of the groups 4A, 5A, 6A, 7A and 8 of the International Periodic Table, and wherein the mixing ratio between an electrically conductive substance stable at elevated temperatures and an insulating substance stable at elevated temperatures, may be adjusted. A thermistor formed of the composition is superior in high-temperature stability and can be used over a broad temperature range because its resistance value can be selected to an optimum value.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: December 19, 1995
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Masaki Iwaya, Kyohei Hayashi, Hiroshi Matsuzaki, Yoshirou Suematsu
  • Patent number: 5462359
    Abstract: A temperature probe in which mechanical oscillatory excitation that can lead to fracture of the connecting lines is prevented and the response time of the temperature probe to temperature changes is shortened. According to the invention, a resistance element is disposed in a flow window of the temperature probe which is formed by a protective bracket and which projects into a flow line. At least one of the connecting lines that is connected with the resistance element exhibits at least one bent point, which is held in at least one retaining opening formed in the protective bracket, whereby the connecting lines are stabilized. The temperature probe may be used for measuring the temperature of intake air in an intake pipe of a mixture-compressing, external-ignition internal combustion engine.
    Type: Grant
    Filed: June 30, 1994
    Date of Patent: October 31, 1995
    Assignee: Robert Bosch GmbH
    Inventors: Asta Reichl, Martin Jenner, Armin Witzig, Anita Rose, Bernd Kuenzl
  • Patent number: 5451921
    Abstract: An electrical assembly in which electrical connection is made to a device having two laminar electrodes and a laminar element between the electrodes, preferably a circuit protection device in which a PTC conductive polymer element is sandwiched between two metal foil electrodes. Connection is made to at least one of the electrodes by a resiliently deformed clip having an active arm which contacts one of the electrodes, and a passive arm which is not in conductive contact with the other electrode. Preferably there is an auxiliary member between the active and passive arms of the clip. The auxiliary member can be an insulator, or a conductive member which is spaced apart from the other electrode but secured to the same face of the PTC element as the other electrode.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: September 19, 1995
    Assignee: Raychem Corporation
    Inventors: Tracy Crawford, Jim D. Beckham, Andrew D. White
  • Patent number: 5451919
    Abstract: A conductive polymer composition which has a resistivity of less than 10 ohm-cm and which exhibits PTC behavior comprises a polymeric component and a particulate conductive filler. The polymeric component comprises a first crystalline fluorinated polymer having a first melting point T.sub.m1 and a second crystalline fluorinated polymer having a second melting point T.sub.m2 which is from (T.sub.m1 +25).degree. C. to (T.sub.m1 +100).degree. C. The composition exhibits one of a number of characteristics, including a relatively high PTC anomaly. The composition is useful in circuit protection devices to be used at high ambient conditions.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: September 19, 1995
    Assignee: Raychem Corporation
    Inventors: Edward F. Chu, Ann Banich, Robert Ives, Steven Sunshine, Chi-Ming Chan
  • Patent number: 5449234
    Abstract: The present invention provides an apparatus for sensing the temperature of surrounding air. The apparatus is thermally isolated from the external environment and more accurately provides an indication of the medium temperature while providing fast response. The apparatus includes a temperature sensing device whose resistance varies with temperature and a conditioning circuit for measuring the resistance and producing an electrical signal which is insensitive to external resistive loading and which has a magnitude responsive to the sensed resistance. The apparatus includes a non-metallic housing which encapsulates the temperature sensitive device and the conditioning circuit. The housing forms a cage portion which surrounds the temperature sensing device and is adapted to protect and to provide air flow to the temperature sensing device.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: September 12, 1995
    Assignee: Caterpillar Inc.
    Inventors: Gregory H. Gipp, Ronald R. Gustin
  • Patent number: 5450053
    Abstract: In a microbolometer infrared radiation sensor, a detector material (VO.sub.2) having a high thermal coefficient of resistance to increase the sensitivity of the apparatus.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: September 12, 1995
    Assignee: Honeywell Inc.
    Inventor: R. Andrew Wood
  • Patent number: 5436609
    Abstract: An electrical device in which a conductive terminal is physically and electrically attached directly or indirectly to a face of a laminar PTC resistive element. The terminal comprises a laminar portion and a non-laminar shaped portion which lies within a projection of the periphery of the PTC resistive element. The shaped portion serves to improve thermal transfer between the PTC element and the atmosphere surrounding the device. Devices of the invention are useful as circuit protection devices.
    Type: Grant
    Filed: July 6, 1993
    Date of Patent: July 25, 1995
    Assignee: Raychem Corporation
    Inventors: Chi-Ming Chan, Shou-Mean Fang
  • Patent number: 5432357
    Abstract: A pair of electrodes 3 are first formed on a substrate. Subsequently, an undoped diamond film is selectively deposited between the above electrodes. A B-doped diamond film is then selectively formed on both the insulating diamond film and part of each electrode. The substrate may be contained in a container provided with an opening portion from which only the B-doped diamond film is exposed.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: July 11, 1995
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventors: Rie Kato, Koji Kobashi
  • Patent number: 5430427
    Abstract: The temperature of a glass cooktop is sensed by an elongated thermistor rod positioned below the cooktop. The thermistor rod has a negative temperature coefficient of electrical resistance and is connected in a control circuit for the cooktop heater. The opposite end portions of the thermistor rod are located outside of the housing for the cooktop heater so that electrical connections to such end portions are not exposed to extremely high temperatures.
    Type: Grant
    Filed: October 20, 1993
    Date of Patent: July 4, 1995
    Assignee: Therm-O-Disc, Incorporated
    Inventors: Robert L. Newman, James A. Tennant
  • Patent number: 5426279
    Abstract: A ceramic heating rate regulator for electrically powered thermal treatment operations is described. The regulator is made of a ceramic mixture containing molybdenum disilicide, which is an electrically conductive substance undergoing crystal structure transformation above 700.degree. C. The regulator comprises an elongated ceramic rod containing high concentration of molybdenum disilicide, the rod is subsequently insulated by a ceramic cylinder which contains silicon nitride and low concentrations of molybdenum disilicide. The regulator when incorporated in the heating circuit of the thermal treatment furnace will itself heat up and thus reduce the size of the heating current flowing in the circuit, as soon as the temperature of the regulator has reached the transformation temperature of molybdenum disilicide. The heating rate regulator is designed to be used in conjunction with conventional temperature controlling devices.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: June 20, 1995
    Inventor: Sankar Dasgupta
  • Patent number: 5425099
    Abstract: A positive temperature coefficient thermistor element comprising a plate-shaped ceramic body made of a ceramic material whose Curie temperature is in the range of 60.degree. to 120.degree. C., and having a thickness of 2.5 to 5.0 mm, and electrodes formed on both major surfaces of the ceramic body.
    Type: Grant
    Filed: April 6, 1994
    Date of Patent: June 13, 1995
    Assignee: Murata Mfg. Co., Ltd.
    Inventors: Kenji Takakura, Katsuyuki Uchida
  • Patent number: 5416462
    Abstract: An electrical resistance element having a resistance body between two contact terminals. The resistance body has PTC behavior and is composed of a polymer matrix and a filler component embedded in the polymer matrix. The filler component is composed of electrically conducting particles. Although the element is of simple and inexpensive construction, the resistance element is notable for good electrical conductivity in the low-resistance state and for a low response time for the PTC transition from the low-resistance to the high-resistance state. This is achieved as a result of the fact that at least some of the electrically conducting particles are formed as composite bodies having electrically conducting surfaces and/or as hollow or porous bodies composed of electrically conducting material. These particles have a lower specific density and/or lower specific heat capacity than solidly formed particles composed of conductive material.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: May 16, 1995
    Assignee: ABB Research Ltd.
    Inventors: Anton Demarmels, Felix Greuter, Ralf Strumpler
  • Patent number: 5414403
    Abstract: A current-limiting component having an electrical resistance body arranged between two contact terminals. The resistance body contains a first resistance material having PTC behavior. Below a limit temperature, the first resistance material has a low cold resistivity and at least one current-carrying path extending between the two contact terminals. Above the limit temperature, the first resistance material has a high hot resistivity compared with its cold resistivity. The current-limiting component has uniform switching capability and high rated current-carrying capacity despite simple and inexpensive construction. The resistance body additionally contains second resistance material having a resistivity which is between the cold resistivity and the hot resistivity of the first resistance material. The second resistance material is in intimate electrical contact with the first resistance material and forms at least one resistance path connected in parallel with the current-carrying path.
    Type: Grant
    Filed: June 4, 1993
    Date of Patent: May 9, 1995
    Assignee: ABB Research Ltd.
    Inventors: Felix Greuter, Claus Schuler, Ralf Strumpler
  • Patent number: 5410291
    Abstract: A thermistor-type temperature sensor having multiple temperature-sensitive elements can detect a wide range of temperatures. In a preferred embodiment, the sensor uses multiple thin thermo-resistive elements having different electrical characteristics, where the elements are disposed on insulating ceramic substrates and covered by insulating sheets. This arrangement provides a low-profile thermistor-type sensor operable over a wide range of temperatures.
    Type: Grant
    Filed: August 26, 1993
    Date of Patent: April 25, 1995
    Assignee: Nippondenso Co., Ltd.
    Inventor: Kaoru Kuzuoka
  • Patent number: 5406246
    Abstract: A positive temperature coefficient temperature sensor for use in exhaust-gas systems of internal-combustion engines includes a sensor element having a multilayer laminate composite structure with a positive temperature coefficient thermistor, formed by at least two resistor tracks arranged one above another and electrically insulated from one another. One of the layers of the multilayer structure is an insulating ceramic base film, and a first one of the at least two resistor tracks, with a supply lead, is printed onto the insulating ceramic base film. A second one of the at least two resistor tracks is disposed separately on the insulating ceramic base film by means of at least one insulating layer printed above the first one of the at least two resistor tracks. The at least two resistor tracks disposed one above another are connected by a land guided through the at least one insulating layer.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: April 11, 1995
    Assignee: Robert Bosch GmbH
    Inventors: Karl-Hermann Friese, Harald Neumann
  • Patent number: 5404126
    Abstract: A fuse resistor protects a circuit from a surge, an overcurrent from an unexpected connection, or the like. When a continuous overvoltage higher than a predetermined value is applied to the circuit, the heat from a heat-generating resistant film fractures an insulating substrate of the fuse resistor to open the circuit. Changing the minimum current to which the fuse resistor responds, by modifying a cutout or notch on the substrate, makes it possible to use the fuse resistor anywhere in the circuit. A discharging-type surge absorbing element with a security mechanism that includes the fuse resistor can thus provide protection against a surge or a continuous overcurrent that is more than the rated value of the fuse resistor.
    Type: Grant
    Filed: June 1, 1993
    Date of Patent: April 4, 1995
    Assignee: Okaya Electric Industries Co., Ltd.
    Inventors: Yoshito Kasai, Yoshiro Suzuki, Akihiko Ikazaki
  • Patent number: 5382938
    Abstract: A PTC element has at least one body and two electrodes. The body or bodies has/have and is/are two parallel surfaces, of an electrically conductive polymer composition with a positive temperature coefficient. At least one of the parallel surfaces on the body, or on one of the bodies, of polymer composition is in free contact with an electrode or with a parallel surface on another body of electrically conductive polymer composition. A pressure device exerts a pressure directed perpendicularly to the parallel surfaces on the body, or the bodies, on the electrodes. The pressure device is preferably provided with pressure-exerting devices with the ability to be resilient. After changing from a low resistance to a high resistance state, the PTC element returns to the initial resistance and is reusable after having been subjected to short-circuit currents. The parallel surfaces on the body, or the bodies, of polymer composition may be concentric.
    Type: Grant
    Filed: October 25, 1991
    Date of Patent: January 17, 1995
    Assignee: Asea Brown Boveri AB
    Inventors: Tomas Hansson, Per-Olof Karlstrom
  • Patent number: 5379022
    Abstract: A thermistor device includes plural thermistor elements in series, one or more of which is shunted with a varistor so that if such thermistor heats up and drops excessive voltage, the current therethrough is diverted to the varistor until other thermistors in series also heat to a high resistance state. The thermistor and varistor elements are thermally joined so that the various thermistor elements are rapidly brought up to temperature and prevent prolonged voltage drop across a protective varistor.
    Type: Grant
    Filed: May 3, 1993
    Date of Patent: January 3, 1995
    Assignee: Fluke Corporation
    Inventors: Glade B. Bacon, Heber P. Farnsworth
  • Patent number: 5376819
    Abstract: An integrated circuit implements an on chip thermal circuit (12) for measuring temperature of an operating integrated circuit die (10) by requiring only one dedicated integrated circuit pin (16). A second integrated circuit pin (18) is utilized but is also connected directly connected to other circuitry (14) on the integrated circuit and is used by the other circuitry at the same time that the integrated circuit die temperature is being measured. In one form, the second integrated circuit pin is a ground terminal. Error voltages coupled to the ground terminal may be removed from the temperature calculation by an external differential amplifier (24).
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: December 27, 1994
    Assignee: Motorola, Inc.
    Inventors: James G. Gay, William B. Ledbetter, Jr.