Thermistor Type Patents (Class 338/22R)
  • Patent number: 6166619
    Abstract: Current limiters, preferably PTC resistors, are used for limiting short-circuit current when connected in series to capacitors and converter valves. Protective devices operating with these PTC resistors are able to work reversibly and respond without arcing. They have a low inductance and can be used in space-saving designs. Protective circuits with such PTC resistors have a low loss, are shake-proof, and can be integrated into an existing cooling circuit. They respond autonomously and enable a flexible application. The PTC resistors preferably are constructed in a meander shape of porous metal foam or a metal braid or fabric and have electrical contact bridges between their resistor tracks. At least 2 resistor tracks that are electrically connected in parallel are arranged at a small distance on top of each other in such a way that partial currents (I1, I2) flow in opposite directions through resistor branches in superposed track areas formed in this manner.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: December 26, 2000
    Assignee: DaimlerChrysler AG
    Inventors: Tudor Baiatu, Peter Etter, Reinhard Fried, Hans-Jurg Wiesmann
  • Patent number: 6163246
    Abstract: A chip-type electronic device has a sintered ceramic body formed by integrally sintering a plurality of ceramic layers, inner electrodes including first electrodes, second electrodes and a third electrode formed inside this sintered ceramic body and outer electrodes formed on both end surfaces of this sintered ceramic body. One end of each of the first electrodes is electrically connected to one of the outer electrodes. Each of the second electrodes is electrically connected to a corresponding one of the first electrodes through an associated one of throughholes through one of the ceramic sheets. The third electrode is electrically connected to the other of the outer electrodes and overlaps with the second electrodes as seen perpendicularly to the planar inner electrodes.
    Type: Grant
    Filed: May 31, 2000
    Date of Patent: December 19, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yukiko Ueda, Masahiko Kawase
  • Patent number: 6160473
    Abstract: In a contact assembly for semiconductor resistors, contact elements (5a, 5b) are designed asymmetrically in such a way that, on mutually opposite side faces of an electrical component (3), they bear on it while being mutually offset.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: December 12, 2000
    Assignee: Siemens Matsushita Components GmbH & Co. KG
    Inventor: Bernd Gruhn
  • Patent number: 6157286
    Abstract: A high voltage, current limiting device is connected in series with a high voltage power source and a protected load to interrupt current for an over-current condition [Typically 50 kA]. The current limiting device includes a current sensor/isolator and a switch connected in series. A current limiter, which may include a fuse or polymer current limiting material, is connected in parallel to the current sensor/isolator. The current sensor/isolator includes a pair of electrically insulated supports secured to a plurality of support rods to maintain the insulated supports at a predetermined fixed spacing to support an expulsion fuse. The expulsion fuse link includes a pair of copper conductors of adequate current carrying capability that are attached to ends of a main weak link fuse. A pair of coil springs hold the weak link fuse under tension to repel the conductors apart when the weak link fuse melts open during an over-current condition.
    Type: Grant
    Filed: April 5, 1999
    Date of Patent: December 5, 2000
    Assignee: General Electric Company
    Inventors: Radhakrishnan Ranjan, Donald Kenneth Ferguson, Anil Raj Duggal, Minyoung Lee
  • Patent number: 6157289
    Abstract: The invention presents a PTC thermistor which is high in adhesive strengths of inner- and outer-layer electrodes composed of metallic foil respectively stuck to conductive sheets, and has a larger current breaking characteristic. It contains a laminated body (13) which is formed by alternately laminating a plurality of conductive sheets (14) and an inner-layer electrode (11) composed of metallic foil having first plated layers (12) so that the conductive sheets (14) can become the outermost layers, an outer-layer electrode (18) positioned at the outermost layer of the laminated body (13), and having a second plated layer (16) on a side facing the inner-layer electrode (11), and side-face electrode layers 20) disposed at facing sides of the laminated body 913) for connecting electrically the inner-layer electrode (11) and outer-layer electrode (18).
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: December 5, 2000
    Assignee: Mitsushita Electric Industrial Co., Ltd.
    Inventors: Junji Kojima, Kohichi Morimoto, Takashi Ikeda, Naohiro Mikamoto
  • Patent number: 6155711
    Abstract: The method of calibrating temperature-measuring resistors on substrates made of glass, glass-ceramics or similar materials, especially conductor strip resistors on glass-ceramic cooking surfaces, includes measuring a temperature associated with a measured resistance value obtained using the temperature-measuring resistor by determining a temperature-dependent electrical resistance of the substrate material, in order to obtain a temperature-resistance characteristic curve for the temperature-measuring resistor.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: December 5, 2000
    Assignee: Schott Glas
    Inventors: Kurt Schaupert, Harry Engelmann
  • Patent number: 6157290
    Abstract: The resistor body of a nonlinear resistor element having PTC characteristics includes a pulverulent first filler, whose material, e.g. TiB.sub.2, TiC, VC, WC, ZrBr.sub.2, MoSi.sub.2, has a specific conductivity of at most 10.sup.-3 .OMEGA.cm and in which the particle sizes are between 10 and 40.mu., and also, in order to improve the voltage sustaining capability by extending the switching zone and to achieve uniform energy absorption, includes a likewise pulverulent second filler having varistor characteristics and particle sizes between 50 and 200.mu., whose specific resistance at field strengths .gtoreq.2000 V/cm such as occur in the switching region of the resistor element and above, is at most 50 .OMEGA.cm, preferably at most 15 .OMEGA.cm, the fillers being embedded in a matrix made of a thermoplastic, in particular HD polyethylene or a thermoset. The average particle size of the second filler should exceed that of the first filler by a factor of from 2 to 5.
    Type: Grant
    Filed: January 7, 1999
    Date of Patent: December 5, 2000
    Assignee: ABB Research Ltd.
    Inventors: Joachim Glatz-Reichenbach, Ralf Strumpler, Jorgen Skindhoj, Felix Greuter
  • Patent number: 6154118
    Abstract: A circuit protective device with a positive temperature coefficient element is provided, which includes: a positive temperature coefficient (hereinafter "PTC") element, made of a conductive composition having a PTC characteristics, provided for shutting off an electric circuit; a circuit board having the PTC element and electrodes to be connected with the PTC element; and a slot formed on the circuit board so as to prevent a low resistance conductive passage from being formed between the electrodes, the low resistance conductive passage being made of powder of the conductive composition released from the PTC element. And also an electric junction box with the above circuit protective device is provided. Thus, the circuit protective device or the electric junction box with the circuit protective device wherein a low resistance conductive passage made of a carbonaceous powder to be released from the PTC element is not formed between the electrodes of the PTC element can be realized.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: November 28, 2000
    Assignee: Yazaki Corporation
    Inventors: Satoshi Ishikawa, Osamu Soda
  • Patent number: 6153861
    Abstract: A heating element, preferably for oblong plate-shaped sensors for measuring oxygen concentration in internal combustion engine exhaust gas, has a conductive heating strip at one end of the heating element and electrical conductors which are connected electrically to the conductive heating strip and which supply the heating current and provide connection to the other end of the heating element. The positive temperature coefficient of the resistor material of the conductive heating strip is lower than the positive temperature coefficient of the material of at least one section of the conductors.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: November 28, 2000
    Assignee: Robert Bosch GmbH
    Inventor: Helmut Weyl
  • Patent number: 6150918
    Abstract: Degaussing units in the form of mono and duo-PTCs are disclosed which can be exposed to high inrush currents without the same leading to fracture at the edges of the ceramic thermistors. The electrode layers of the thermistor(s) completely cover the main surfaces and are composed of a material which comprises a silver alloy containing minimally 4 wt. % and maximally 12 wt. % zinc, and which is applied directly on to the thermistor by means of screen printing. In a preferred embodiment, an alloy containing approximately 6 wt. % zinc is used.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: November 21, 2000
    Assignee: BC Components Holdings B.V.
    Inventor: Reinhilde P. M. Berger
  • Patent number: 6147330
    Abstract: A PTC thermistor element for a heating device has a main body of a layered structure having a thinner layer and a thicker layer, sandwiched between electrodes formed on the main outer surfaces facing away from each other. The thinner layer has a thickness 0.05-0.43 times that of the thicker layer and is made of a PTC thermistor material with a Curie temperature which is lower than that of the thicker layer by 20.degree. C. or more. The center of heat generation is thus shifted towards the electrode formed on the thinner layer, and a heating plate contacting it can be effectively heated.
    Type: Grant
    Filed: March 1, 1999
    Date of Patent: November 14, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yutaka Ikeda, Takashi Shikama, Yuichi Takaoka, Kenjiro Mihara
  • Patent number: 6147589
    Abstract: It is an object of the present invention to provide an improved negative temperature coefficient thermistor capable of increasing an adhesion strength between a negative temperature coefficient thermistor element consisting of LaCoO.sub.3 rare earth transition element oxide on one hand and electrodes on the other, thereby improving a reliability of the thermistor product. The negative temperature coefficient thermistor of the present invention is obtained by forming electrodes on the surface of a negative temperature coefficient thermistor element consisting of LaCoO.sub.3 rear earth transition element oxide. Such electrodes are formed by adding one or more kinds of oxide powders of Ni, Cr, Mn and Fe in a metal powder, with the content of the oxide powders in the metal powder being 1.0 wt % or less (however, not including 0 wt %).
    Type: Grant
    Filed: February 23, 2000
    Date of Patent: November 14, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Kingo Ohmura
  • Patent number: 6144540
    Abstract: A molded case circuit breaker and current suppressing unit protects an electric motor without tripping during motor current reversal. The circuit breaker trip unit provides long time, short time and instantaneous over current protection against abnormal overload and low-current short circuit currents within the protected circuit. The current suppressing unit rapidly suppresses high-current short circuit currents until the circuit breaker responds to isolate the protected equipment.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: November 7, 2000
    Assignee: General Electric Company
    Inventors: David Arnold, Anil R. Duggal, Lionel M. Levinson
  • Patent number: 6143207
    Abstract: Provided are wide-range thermistor materials with high responsibility, which have linear resistance temperature characteristics and a large rate of temperature-dependent resistance change in wide temperature range of from lower than room temperature to higher than 1000.degree. C. The thermistor material comprises an electrically-insulating ceramic matrix and second phase grains as discontinuously dispersed in the matrix, in which the second phase grains are of a semiconductive or conductive substance having a large rate of temperature-dependent resistance chance. The material may optionally contain a resistance-controlling additive of one or more of nitrides, borides, silicides, sulfides, oxides and carbide of elements, third phase grains with internal stress-relaxing ability having a lower modulus of elasticity than the matrix and the second phase grains, and a resistance stabilizer of TiO.sub.2 and/or Ti.sub.n O.sub.2n-1 (n=4 to 9).
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: November 7, 2000
    Assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
    Inventors: Katsunori Yamada, Mitsuru Asai, Nobuo Kamiya, Yuko Matsubara
  • Patent number: 6143206
    Abstract: An organic positive temperature coefficient thermistor comprising a thermoplastic polymer matrix, a low-molecular organic compound having a melting point that is equal to or greater than 40.degree. C. and less than 100.degree. C. and conductive particles, each having spiky protuberances, is obtained by crosslinking a milled mixture of these components with a silane coupling agent comprising a vinyl group or a (meth)acryloyl group and an alkoxy group. This organic positive temperature coefficient thermistor has sufficiently low resistance at room temperature and a large rate of resistance change between an operating state and a non-operating state, and can be operated at less than 100.degree. C. with a reduced temperature vs. resistance curve hysteresis, ease of control of operating temperature, and high performance stability.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: November 7, 2000
    Assignee: TDK Corporation
    Inventors: Tokuhiko Handa, Yukie Yoshinari
  • Patent number: 6144286
    Abstract: A Positive Temperature Coefficient of Resistance resistor includes a ceramic material of the composition [(Ba.sub.1-e-x Sr.sub.x R.sub.e).sub.1-a M.sub.a ][(Ti.sub.1-b-d N.sub.b Q.sub.d)].sub.c O.sub.3, wherein M is a trivalent or quadrivalent element or a mixture of two or several of these elements; N is a quinquevalent or hexavalent element or a mixture of two or several of these elements; Q is a quadrivalent element or a mixture of two or several of these elements; R is a bivalent element or a mixture of two or several of these elements; and 0.5.ltoreq.x.ltoreq.1, a is 0 or 0.0003.ltoreq.a.ltoreq.0.3, and b is 0 or 0.0003.ltoreq.b.ltoreq.0.3, 0.8.ltoreq.c.ltoreq.1.2, 0.ltoreq.d.ltoreq.0.2, and 0.ltoreq.e.ltoreq.0.2.
    Type: Grant
    Filed: April 21, 1999
    Date of Patent: November 7, 2000
    Assignee: Dornier GmbH
    Inventors: Ralf Moos, Marco Fandel, Wolfgang Schaefer
  • Patent number: 6140906
    Abstract: A resistive temperature sensor is constituted by an insulating body mainly composed of alumina; and a temperature sensing resistor mainly composed of a conductive material containing a metal silicide. The insulating body and the temperature sensing resistor are laminated and sintered to form a lamination sintered body in which a resistance circuit is formed.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: October 31, 2000
    Assignee: TDK Corporation
    Inventors: Nobuo Kaihara, Minoru Ogasawara, Masatada Yodogawa
  • Patent number: 6134771
    Abstract: An electronic part in which insulating tape is adhered to lead terminals which extend from an electronic part unit so that a pitch between the terminals can remain stable and constant. The insulating tape is adhered to portions of the lead terminals in a vicinity of the unit from both sides such that the tape is placed with the terminals therebetween.
    Type: Grant
    Filed: December 31, 1996
    Date of Patent: October 24, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Toshikazu Nakamura, Takashi Shikama
  • Patent number: 6136231
    Abstract: The present invention relates to rare earth elemental thermistors and compositions useful for making such thermistors. In particular, it relates to yttrium and chromium oxide based thermistor systems having at least two phases: YCrO.sub.3 and Cr.sub.2 O.sub.3 and their use for measuring temperature.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: October 24, 2000
    Assignee: Keystone Thermometrics, Inc.
    Inventor: David J. Sorg
  • Patent number: 6133819
    Abstract: A load-dependent, preventive fuse with an electronic ceramic (12) in a housing (11) from which connection leads (14) are led outwards to detect at least a first type of load to which a device to be monitored is subjected, in which fuse use is made of a ceramic material, hereinafter referred to as TDR ceramic (12), whose electrically insulating state changes as a function of time, being the first type of load, and as a function of a second type of load, to a semiconducting state, and as a result thereof, when a dc voltage U is applied to the TDR ceramic (12) via connection leads (14) an increase in current forms the activation criterion for the fuse, which criterion is fulfilled under predeterminable conditions and determines a desired operating time .tau..
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: October 17, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Albert Comberg, Rainer Waser
  • Patent number: 6133820
    Abstract: An exemplary current limiting device comprises first and second electrodes; a composite material between the first and second electrodes, the composite material comprising: (a) a binder, and (b) an electrically conductive filler; a thin layer which provides an inhomogeneous distribution of resistance to the device; a web which reinforces the composite material; and a pressurizer for pressing the electrodes against the composite material; wherein the web is disposed in a volume of the composite material which does not include the thin layer. The current limiting device is simple and reusable, and can be tailored to a plurality of applications, including high voltage/current distribution systems, to protect sensitive components from high fault currents. The device has a robust structure which allows it to repeatedly withstand the high mechanical and thermal stresses which typically accompany switching events in high voltage/current circuits.
    Type: Grant
    Filed: August 12, 1998
    Date of Patent: October 17, 2000
    Assignee: General Electric Company
    Inventors: Anil Raj Duggal, Minyoung Lee, Siegfried Aftergut
  • Patent number: 6133821
    Abstract: A PTC thermistor has a disk-shaped main body with electrodes on its main surfaces which are facing mutually away from each other such that, during an initial period after a potential difference is applied between these electrodes, the side surface of the main body has an asymmetric temperature distribution between the electrodes in the direction normal to its main surfaces. The heat emission does not have a peak half-way between the electrodes in the direction of the thickness such that the thermistor has an improved resistance against flash pressure. This may be done by forming the electrodes in different sizes or by providing a non-uniform distribution in specific resistance to the main body such that the heat-emission peak is displaced from the center region between the two main surfaces of the main body.
    Type: Grant
    Filed: October 13, 1998
    Date of Patent: October 17, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yasuhiro Nabika, Takeo Haga
  • Patent number: 6130597
    Abstract: An electrical device in which a resistive element composed of a conductive polymer composition and two electrodes is made by a method in which the device is cut from a laminate of the conductive polymer composition and the electrodes, is exposed to a thermal treatment at a temperature above the melting temperature of the conductive polymer composition, and is then crosslinked.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: October 10, 2000
    Inventors: James Toth, Mark F. Wartenberg, Mark Bannick
  • Patent number: 6128168
    Abstract: A fault current interrupter is provided by the parallel combination of a polymer current limiter and a voltage dependent resistor connected across a pair of separable contacts to permit the interruption of current without the occurrence of arcing between the contacts when the contacts first become separated. The polymer current limiter is selected to have a relatively low resistance at quiescent operating currents and a substantially higher resistance at short circuit overcurrents. This allows the current to transfer away from the contacts through the polymer current limiter until the voltage across the voltage dependent resistor causes the voltage dependent resistor to become conductive and thereby transfer the current away from the polymer current limiter.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: October 3, 2000
    Assignee: General Electric Company
    Inventors: David Arnold, Anil R. Duggal, Lionel M. Levinson, Harold Jay Patchen, Larry Neil Lewis
  • Patent number: 6127914
    Abstract: Described are a thin-film temperature-sensitive resistor material which comprises, at a temperature-sensitive resistor portion, a mixed crystal of a nitride and oxide of a transition metal such as vanadium preferably, that represented by the formula: MN.sub.x O.sub.y wherein 0<x<1, and 2.ltoreq.y.ltoreq.13/6, simultaneously exhibits a high temperature coefficient of resistance and a low specific resistance at about room temperature, and has excellent sensitivity at about room temperature; and a process for the production of a thin-film temperature-sensitive resistor material, which comprises forming its temperature-sensitive resistor portion by using a gas-atmosphere composed mainly of a nitrogen gas preferably, a mixed gas composed of nitrogen, argon and oxygen, and has a flow rate ratio of nitrogen to oxygen (nitrogen/oxygen) of 14/1 to 23/1.
    Type: Grant
    Filed: May 19, 1998
    Date of Patent: October 3, 2000
    Assignee: NEC Corporation
    Inventor: Tokuhito Sasaki
  • Patent number: 6125529
    Abstract: The present invention relates to making sensors by cutting pieces from a boule or ingot of a metal oxide single crystal. The sensors produced are also described.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: October 3, 2000
    Assignee: Thermometrics, Inc.
    Inventors: Carol Zwick Rosen, Donald G. Wickham, John Carter, Jr., David Sorg
  • Patent number: 6124780
    Abstract: A current limiting device comprises at least two electrodes; an electrically conductive composite material between the electrodes; interfaces between the electrodes the said composite material; and an inhomogeneous resistance distribution structure at the interfaces. During a high current event, adiabatic resistive heating at the interfaces causes rapid thermal expansion and vaporization and at least a partial physical separation at the interfaces; so the resistance of the current limiting device increases. The composite material comprises at least one polymeric matrix material and at least one electrically conductive material, and the polymeric matrix material comprises at least one epoxy and at least one silicone.
    Type: Grant
    Filed: May 20, 1998
    Date of Patent: September 26, 2000
    Assignee: General Electric Company
    Inventors: Anil Raj Duggal, Siegfried Aftergut, Larry Neil Lewis, David Alan Nye
  • Patent number: 6124781
    Abstract: A battery protection device includes an upper foil electrode laminated to the upper surface of a conductive polymer PTC layer, and a lower foil electrode laminated to the lower surface of the PTC layer. An isolated portion of the lower electrode is formed by creating an annular isolation gap in the lower electrode. A first via is formed through the upper electrode, the PTC layer, and the isolated portion of the lower electrode. The diameter of the first via is smaller than the diameter of the isolated electrode portion, so that an annular area of the isolated electrode portion is left between the opening and the isolation gap. The internal wall surface of the first via and the annular electrode area are plated with a conductive metallization layer, which forms a first contact seat that is conductively connected by the metallized surface of the first via with the upper electrode. A first contact element is fixed to the first contact seat.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: September 26, 2000
    Assignee: Bourns, Inc.
    Inventors: Steven D. Hogge, Andrew Brian Barrett
  • Patent number: 6114942
    Abstract: A PTC device which surely achieve effective space utilization while easily excluding the possibility of the formation of a short circuit. The PTC device includes a PTC component 3 comprising a first electrode 11, a second electrode 13, and a PTC element 9 disposed between these electrodes, a first electrically conductive lead 15 which is connected to the first electrode and able to connect with a button terminal of a battery, a second electrically conductive lead 18 which is connected to the second electrode, and an insulating element 23. The insulating element covers the inner periphery 7 of the PTC component, the second electrode and a portion of the second electrode and the second electrically conductive lead on the second electrode.
    Type: Grant
    Filed: April 9, 1998
    Date of Patent: September 5, 2000
    Assignee: KK Raychem
    Inventors: Yoshitaka Kitamoto, Takashi Hasunuma, Shozo Fukuyama, Naofumi Miyasaka
  • Patent number: 6107909
    Abstract: An electrical resistor having a resistance value and capable of withstanding high power surges, utilizing a thick film deposited on a substrate and trimmed with one or more cuts configured to maintain a level of current crowding while increasing the resistance value of the resistor. A surge resistor can be modified in a similar fashion.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: August 22, 2000
    Assignee: Microlectronic Modules Corporation
    Inventor: John P. Kosinski
  • Patent number: 6104274
    Abstract: A composite PTC material made of cristobalite as a matrix and a conductive filler, having a room temperature resistivity of 10.sup.-1 .OMEGA.cm or less. The conductive filler is at least one substance selected from the group consisting of single metals, metal silicides, metal carbides and metal borides; has a room temperature resistivity of 10.sup.-3 .OMEGA.cm or less when per se made into a sintered material; has particle diameters of 2-50 .mu.m; and is contained in a proportion of 20-35% by volume of the composite PTC material. The composite PTC material has a relative density of 90% or more after firing.
    Type: Grant
    Filed: March 5, 1998
    Date of Patent: August 15, 2000
    Assignee: NGK Insulators, Ltd.
    Inventors: Kazuyuki Matsuda, Junko Shibata, Kiyoshi Araki
  • Patent number: 6104587
    Abstract: An electrical device which includes a resistive element which exhibits PTC behavior, is composed of a conductive polymer composition, has a planar shape with first and second major surfaces, and has a thickness of at most 0.64 mm . The resistive element is sandwiched between first and second metal foil electrodes, at least one of which has a thickness of at least 0.055 mm, so that the ratio of the resistive element thickness to electrode thickness is 1:1 to 16:1. The device can be used as a circuit protection device in an electrical circuit.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: August 15, 2000
    Inventors: Ann Banich, Edward F. Chu
  • Patent number: 6099164
    Abstract: The invention is directed to a thermistor created using a monocrystalline form of a nickel-manganese-oxide cubic spinel and methods of using same as a sensor in an electrical circuit.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: August 8, 2000
    Assignee: Thermometrics, Inc.
    Inventors: Carol Zwick Rosen, John Carter, Jr.
  • Patent number: 6097276
    Abstract: A description is given of a precision resistor. The resistor comprises a substrate having two connections which are electrically interconnected via a resistance path, said resistance path comprising a first path portion having a positive TCR and a second path portion having a negative TCR. The resistor is characterized in that the resistance material of both path portions is selected so that the resistance values and the absolute TCRs of both path portions are comparable and in that both path portions are trimmed so that the resistor has desired resistance and TCR values. Preferably, the resistance materials used for the path portions consist of an alloy of substantially the same composition on the basis of CuNi or NiCrAl. The invention makes it possible to very accurately and reproducibly mass-produce precision resistors.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: August 1, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Jan J. Van Den Broek, Anton Heger
  • Patent number: 6094129
    Abstract: PTC thermistors are used in reversible short circuit current limiters, in particular in series connection with electrical valves and/or capacitors. An electrically insulated, thermally conductive insulation or ceramic layer (20) is in contact electrically and with good thermal conduction via a first main surface with a metallic cooling element (25). A second main surface of the ceramic layer (20), opposite the first main surface, is covered with an electrically insulating thermal-conduction layer (21) having a thickness in the range from 10 .mu.m-100 .mu.m. Meandering tracks (16) of the resistive body of the PTC thermistor (5) are pressed between this thermal conduction layer (21) and an electrically insulating, preferably thermally conductive, flexible high-temperature stable polymer film (22). In order to provide pressure, a pressure compensation cushion (23) on which a force (F) orthogonal to the second main surface of the ceramic layer (20) acts, may be provided.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: July 25, 2000
    Assignee: DaimlerChrysler AG
    Inventor: Tudor Baiatu
  • Patent number: 6090314
    Abstract: The organic positive temperature coefficient thermistor of the invention comprises a polyalkylene oxide, a water-insoluble organic compound and conductive particles having spiky protuberances, and so can operate at less than 100.degree. C. that is harmless to the human body, with low initial resistance in a non-operating state (at room temperature), and a large rate of resistance change upon transition from the non-operating state to an operating state, and improved humidity resistance.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: July 18, 2000
    Assignee: TDK Corporation
    Inventors: Tokuhiko Handa, Yukie Yoshinari
  • Patent number: 6090313
    Abstract: A high temperature PTC device comprising a polymeric conductive composition that includes nylon-11 and a carbon-based particulate conductive filler has a switching temperature greater than 150.degree. C., preferably between about 160.degree. C. and 200.degree. C. The composition demonstrates a high PTC effect (at least 10.sup.3, and more typically 10.sup.4 to 10.sup.5 or greater) and a resistivity at 25.degree. C. of 100 .OMEGA.cm or less, preferably 10 .OMEGA.cm or less. High temperature PTC devices that comprise nylon-11 or nylon-12 compositions and that are manufactured by extrusion/lamination demonstrate good thermal and electrical stability compared with those manufactured by compression molding and do not require composition crosslinking for stability, although crosslinking may be used to further improve stability. The use of a high temperature solder for attaching electrical terminals to the device improves the PTC properties of the device.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: July 18, 2000
    Assignee: Therm-O-Disc Inc.
    Inventor: Liren Zhao
  • Patent number: 6083426
    Abstract: A conductive paste having excellent printing properties, which can be used for manufacturing heat-resistant conductors and resistive elements, is described. Such a conductive paste can be obtained by preparing as a binder a polyimide precursor whose weight average degree of polymerization (n) ranges from 5 to 20, and mixing it with a solvent and a conductive powder. The polyimide precursor preferably is included in the range from 50 to 80 weight parts to 100 weight parts of the solvent. A polar solvent, or a mixed solvent including a polar solvent and a nonpolar solvent can be used. A preferable mixed solvent is a mixture of N-methyl-2-pyrrolidone and diethylene glycol dimethyl ether, in which the mixing volume ratio is preferably ranging from 2:8 to 9:1, more preferably, 2:8 to 3:7.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: July 4, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yukihiro Shimasaki, Yusuke Ozaki, Masanaru Hasegawa, Toshiyuki Kitagawa
  • Patent number: 6081181
    Abstract: Electrodes on both ends of a thermistor chip element each have a first metal layer formed on the thermistor chip element and a second metal layer which has a smaller area than the first metal layer and is formed on the first metal layer such that the mutually opposite edge parts of the first metal layers are exposed. Third metal layers are formed over the second metal layers. A fourth metal layer may be formed between the first and second metal layers.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: June 27, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Masahiko Kawase, Hidenobu Kimoto, Norimitsu Kito, Ikuya Taniguchi
  • Patent number: 6078250
    Abstract: A resistor element has a ceramic body with a first outer electrode and a second outer electrode formed on its mutually opposite externally facing end surfaces and a plurality of mutually oppositely facing pairs of inner electrodes inside the ceramic body. Each of these pairs has a first inner electrode extending horizontally from the first outer electrode and a second inner electrode extending horizontally from the second outer electrode towards the first outer electrode and having a front end opposite and separated from the first inner electrode by a gap of a specified width, these plurality of pairs forming layers in a vertical direction. The gap of at least one of these plurality of pairs of inner electrodes is horizontally displaced from but overlapping with the gaps between the other pairs of inner electrodes. For producing such a resistor element, the distance of displacement is set according to a given target resistance value intended to be had by the resistor element.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: June 20, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yukiko Ueda, Masahiko Kawase, Norimitsu Kitoh
  • Patent number: 6076965
    Abstract: A nickel-cobalt-manganese oxide monocrystal having a cubic spinel structure over a broad concentration range of manganese/cobalt/nickel, including the entire possible range of manganese to nickel ratios, provided that the resulting monocrystal has a cubic spinel structure. A flux method is described for producing the monocrystals. Also disclosed are sensors, based on the monocrystals, having desirable electrical properties In particular, the sensors of the present invention are highly accurate temperature sensors or thermistors having high sensitivity, good reproducibility and improved aging characteristics. Performance of a sensor based on the monocrystal permits the preparation of a thermistor standard which can be used to evaluate the performance of ceramic devices.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: June 20, 2000
    Assignee: Therometrics, Inc.
    Inventors: Carol Zwick Rosen, Donald G. Wickham
  • Patent number: 6074576
    Abstract: The invention provides polymeric PTC compositions and electrical PTC devices that have a high voltage capability and are capable of operating at alternating current (AC) voltages of 110 to 130 volts or greater, such as those present in household AC electrical lines. The polymeric compositions demonstrate a high PTC effect of at least 10.sup.4 to 10.sup.5 and a low initial resistivity at 25.degree. C. of 100 .OMEGA.cm or less, preferably 10 .OMEGA.cm or less, resulting in electrical PTC devices having a resistance at 25.degree. C. of 500 m.OMEGA. or less, preferably about 7.5 m.OMEGA. to about 200 m.OMEGA., typically about 10 m.OMEGA. to 100 m.OMEGA.. The devices of the invention can withstand a voltage of 110 to 130 VAC or greater without failure for at least 4 hours, preferably up to 24 hours or more, after reaching the switching temperature.
    Type: Grant
    Filed: November 16, 1998
    Date of Patent: June 13, 2000
    Assignee: Therm-O-Disc, Incorporated
    Inventors: Liren Zhao, Prasad S. Khadkikar
  • Patent number: 6040755
    Abstract: A chip thermistor is produced by providing a planar rectangular thermistor block with a pair of electrodes formed on its surfaces, each of the electrode being formed so as to be in part on a different one of the main surfaces and extending continuously at least onto one of the side surfaces. The thermistor block thus prepared is cut transversely to obtain a plurality of thermistor elements. A specified number of these thermistor elements are then aligned and stacked one on top of another with their main surfaces facing each other. A layer of an insulating material such as glass with thickness greater than 10 .mu.m is inserted between each mutually adjacently stacked pair of these thermistor elements. Outer electrodes are formed on the outer surfaces of the stacked structure so as to electrically connect to the electrodes on the stacked thermistor elements on their aligned end surfaces.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: March 21, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yoshiaki Abe, Toshiharu Hirota
  • Patent number: 6028295
    Abstract: An improved mounting apparatus for the attachment of a filament heater between electric conduction plates of a space heater device comprises a first electric conduction plate, a second electric conduction plate, a plurality of filament heaters positioned between the electric conduction plates, a plurality of electric conduction rings positioned on opposite sides of each of the filament heaters, and a seat having a receiving trough for receiving the electric conduction plates and the filament heaters therein. Each of the electric conduction plates includes a suitable mounting hole therein. An elastic pressing piece extends around the mounting holes so as to exert a compressing force upon the respective electric conduction rings on the filament heaters. The seat includes suitable pillars that can receive screws so as to secure the electric conduction plates and the filament heaters within the seat.
    Type: Grant
    Filed: December 14, 1998
    Date of Patent: February 22, 2000
    Inventor: Chern-Bao Rong
  • Patent number: 6027246
    Abstract: Monocrystalline nickel-cobalt-manganese-copper oxide having a cubic spinel structure over a broad range of concentration ratios of manganese/cobalt/nickel/copper, including methods of producing such monocrystals, particularly those having a quaternary cubic spinel structure. Sensors having desirable electrical properties are disclosed, which sensors comprise at least a portion of such monocrystals. In particular, such sensors are highly accurate temperature sensors or thermistors having high sensitivity, good reproducibility and improved aging characteristics.
    Type: Grant
    Filed: December 16, 1997
    Date of Patent: February 22, 2000
    Assignee: Thermometrics, Inc.
    Inventors: Carol Zwick Rosen, Donald G. Wickham
  • Patent number: 6025556
    Abstract: An electronic component includes a main element such as a thermistor having electrodes formed on its surfaces, and lead terminals are electrically connected to these electrodes. A resin coating covers the main element, and both the main element and the lead terminals, except their tip parts away from the main element, are covered with another resin coating of an electrically insulating and flexible resin material.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: February 15, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tatsuya Yoshimura, Yoshiyuki Yamashita, Minoru Shimada
  • Patent number: 6025771
    Abstract: A positive temperature coefficient (PTC) thermistor device for improving workability during assembly of a PTC thermistor element in a casing while eliminating risk of damaging electrode surfaces with enhanced element position stability. To this end, the casing is provided with an insulating guide section for guiding the PTC thermistor element at or near one end, causing the PTC thermistor element to be elastically held by first and second terminals both at a position on one electrode surface which position is near the other edge of the PTC thermistor element and at a position centrally placed on the remaining electrode surface. The guide section essentially consists of first and second guide sections which oppose each other with the PTC thermistor element being sandwiched between, allowing PTC thermistor element to be held by either one of the first and second guide sections and by the first and second terminals.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: February 15, 2000
    Assignee: TDK Corporation
    Inventors: Kazumi Kobayashi, Tsutomu Kotani, Kazuo Saitoh
  • Patent number: 6023403
    Abstract: The present invention is a device for protecting an electrical circuit. The device includes a resistive element having a first and a second surface. A first electrode is in electrical contact with the first surface of the resistive element and a second electrode is in electrical contact with the second surface of the resistive element. A first end termination electrically connects the circuit and the first electrode. A second end termination electrically connects the second electrode and the circuit. An electrically insulating layer is interposed between the first and second end terminations and is in contact with the first and second electrodes. The end terminations allow for an electrical connection to be made to both electrodes from the same side of the electrical device.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: February 8, 2000
    Assignee: Littlefuse, Inc.
    Inventors: Katherine M. McGuire, Honorio Luciano
  • Patent number: 6020809
    Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.
    Type: Grant
    Filed: February 9, 1999
    Date of Patent: February 1, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Michio Miyazaki, Haruyuki Takeuchi, Tadao Bekku
  • Patent number: RE36615
    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: August 29, 1997
    Date of Patent: March 14, 2000
    Assignee: Honeywell Inc.
    Inventor: R. Andrew Wood