US3898422A - PTC heater assembly bonding - Google Patents

PTC heater assembly bonding Download PDF

Info

Publication number
US3898422A
US3898422A US428180A US42818073A US3898422A US 3898422 A US3898422 A US 3898422A US 428180 A US428180 A US 428180A US 42818073 A US42818073 A US 42818073A US 3898422 A US3898422 A US 3898422A
Authority
US
United States
Prior art keywords
heater
ptc
heat
surface portion
resins
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US428180A
Other languages
English (en)
Inventor
Peter G Fuller
Hans A Stoeckler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Texas Instruments Inc
Original Assignee
Texas Instruments Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Texas Instruments Inc filed Critical Texas Instruments Inc
Priority to US428180A priority Critical patent/US3898422A/en
Priority to GB5334374A priority patent/GB1468720A/en
Priority to IT54486/74A priority patent/IT1024412B/it
Priority to CA215,925A priority patent/CA1024202A/en
Priority to DE19742459664 priority patent/DE2459664B2/de
Priority to JP49146262A priority patent/JPS5096944A/ja
Priority to FR7442280A priority patent/FR2256621B1/fr
Application granted granted Critical
Publication of US3898422A publication Critical patent/US3898422A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/02—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient
    • H01C7/022—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having positive temperature coefficient mainly consisting of non-metallic substances
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/02—Details
    • H05B3/06—Heater elements structurally combined with coupling elements or holders
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
    • H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
    • H05B3/146—Conductive polymers, e.g. polyethylene, thermoplastics

Definitions

  • ABSTRACT An assembly comprising a PTC heater, a body to be heated thereby, and a bonding layer interposed therebetween.
  • the heater is formed from a ceramic type PTC electrical resistance material which will generate heat in response to the flow of electric current therethrough. It has a surface portion through which heat is to be transferred and through which electrical current will flow.
  • the body to be heated has a thermally and electrically conductive surface portion of a shape which substantially matches that of the heater surface portion.
  • the body has a thermal coefficient of expansion differing from that of the heater resistance material.
  • the layer of bonding material is electrically and thermally conductive and is interposed between these surface portions for the transfer of heat and conduction of electric current therethrough. It comprises a mixture of small electrically and thermally conductive particles dispersed throughout a flexible, elastic and creep-resistant high temperature resin material stable at temperatures on the order of at least 150C. and free of components which tend to degrade the PTC material.
  • This invention relates to PTC heater assembly bonding and more particularly to such assemblies in which ceramic-type PTC heaters are bonded to bodies to be heated to elevated temperatures.
  • Positive temperature coefficient (PTC) resistance materials are widely utilized as heaters in thermal relays, time-delay relays and other thermally responsive devices and apparatus.
  • Ceramic-type PTC material is commonly used for fabrication of such heaters. Typical of these are barium titanate and related divalent titanates and zirconates which undergo solid phase changes at particular temperatures. Associated with these phase changes are abrupt and large changes in the resistivity of the materials.
  • These ceramic PTC materials generally include dopants such as rare earth metal, antimony or bismuth, or other elements to provide desired characteristics. For example, lead and strontium may be employed to increase or decrease the anomaly temperature range of these materials.
  • Such heaters are fixed to a body to be heated so as to be in close heat-exchange relationship therewith and usually also to provide an electrically conductive path because the electrical circuit supplying power to the heater desirably includes or utilizes the usually electrically conductive body in the circuit.
  • epoxybased resin materials carrying conductive particles interspersed therethrough have generally been used.
  • This interposed layer of epoxy-conductive particle material forms a good thermal and electrical bond between the PTC heater face and the face of the body to be heated.
  • the bond is a relatively rigid bond and has certain disadvantages. There is a substantial difference in the thermal expansions of this epoxy-based bonding material and the PTC.
  • the epoxy and its curing agent tend to degrade the PTC anomaly by causing a chemical reaction within the bulk of the PTC ceramic.
  • a decrease in PTC resistance at the operating temperature may cause electrical run-away and lead to catastrophic breakdown.
  • Epoxies and related organic synthetic resins belong to a family of materials that have a rated prolonged lifetime at temperatures around 150C. At higher temperatures, these organic materials undergo kinetically controlled thermal degradation. Since these resin materials are used as host matrices for the conducting particles, such thermal degradation will cause destructive effects on the electrical and thermal properties of the interface per se.
  • an assembly of the present invention comprises a heater formed from a ceramic-type PTC electrical resistance maerial which will generate heat in response to the flow of electric current therethrough.
  • the heater has a surface portion through which heat is to be transferred and through which electrical current will flow.
  • the assembly includes a body which is to be heated and which has a thermally and electrically conductive surface portion of a shape which substantially matches that of the heater surface portion and to which heat is to be transferred from the heater.
  • the body has a thermal coefficient of expansion differing from that of the heater resistance material.
  • the assembly also has a layer of electrically and thermally conductive bonding material interposed between the surface portions for the transfer of heat and conduction of electric current therethrough. This layer comprises a mixture of small electrically and thermally conductive particles dispersed throughout a flexible, elastic and creepresistant high temperature resin material stable at temperatures on the order of at least C. and free of components which tend to degrade the PTC material.
  • FIG. 1 is an elevation of a heater assembly of the present invention on an enlarged scale
  • FIGS. 2 and 3 are similar elevations of alternate embodiments of the present invention.
  • a thermal relay is generally indicated at 1.
  • This relay has a conductive metal, e.g., copper or aluminum, housing or body 3 having a thermally and electrically conductive substantially flat surface portion 5 to which heat is to be transferred and which serves as an electrode or terminal to carry electrical current to a generally flat cylindrical or pill-shaped PTC heater 7.
  • a layer of electrically and thermally conductive bonding material 9 is interposed between body surface portion 5 and inner surface 11 of heater 7.
  • the bottom is substantially flat or otherwise substantially matches the shape of body portion 5.
  • a resilient electrically conductive spring 13 (secured to a conventional case not shown) for relay 1 bears against the outer surface of pill 7 thereby providing an electrical connection thereto and applying a mechanical force to bias heater 7 against body 3.
  • the top portion of relay 1 is shown in phantom to include at least one relay terminal 15 and an electrical terminal 17 contacting body 3 for connection to an electrical circuit to supply power to heater 7.
  • Layer 9 is relatively thin (e.g., 34 mils thick) and formed of a flexible, elastic and creep-resistant high temperature resin material stable at temperatures on the order of at least 150C. and free of components which tend to degrade the ceramic PTC material.
  • This resin has a major portion by weight of conductive particles, such as silver, silver-copper alloys, graphite, etc., interspersed therethrough.
  • conductive particles such as silver, silver-copper alloys, graphite, etc.
  • about 60-85 percent or more by weight of conductive metal particles of an average size of about 1 micron is employed in a silicone or polyimide resin.
  • Typical silicone resins are those obtainable under the trade designations 525, SR-l55, SR-520, SR-527 and SR-585 from General Electric.
  • Another high temperature resin for this purpose is that obtainable under the trade designation AI-lO from Amoco Chemicals Corp.
  • Other high temperature resin materials, i.e., those useful at temperatures in the order of about 500F. include benzophenone, polyarnide-imide, polybenzimidazoles, polybenzothiazoles, polyethyleneimines, phosphonitrilic and polyester resins.
  • Bonding layer 9 thus permits relative movement and differential expansion of the heater and the body during heat cycling without loss of thermal and electrical contact therebetween.
  • the relatively loose or weak mechanical coupling between the substrate or body and the heater assures that the equilibrium positions of the conducting particles are minimally disturbed and this avoids particle-particle separation which leads to areing and degradation of the layer.
  • the electrical switching characteristics of layer 9 are as good as those of epoxy resin materials. Chemical additives that avoid making the layer rigid and do not effect degradation of the PTC anomaly (amine curing agents are undesirable because of this) may be used, if desired, but are not essential.
  • FIG. 2 a heater assembly bonding, similar to that of FIG. 1, is illustrated at 1A except the body surface portion 5 is defined by a projecting ridge and a preformed layer 9A in sheet form is employed.
  • a sheet of silver-particle loaded silicone resin is available under the trade designation 850-Consil from Technical Wire Products Inc.
  • the assembly of FIG. 2 allows the PTC pill to expand axially, limited only by the spring force of 13, while the ridge somewhat limits movement laterally.
  • FIG. 3 illustrates still another embodiment 18 of the present invention, quite similar to that of FIG. 2, wherein the body surface portion 5 is recessed and a layer is a sheet of high temperature resinconductive particles formed to fit within the recess, thus improving heat transfer between the PTC pill and body 3 due to larger surface area in contact with the PTC ceramic.
  • the spring 13 may be utilized to provide sufficient force to maintain the heater in its equilibrium position.
  • Typical applications of the assemblies of this invention are in time-delay relays where the PTC heater actuates a bimetal plate, and an automatic choke control where the PTC ceramic heater is used to actuate a bimetal spring that adjusts the fuel/air ratio.
  • An assembly comprising:
  • a heater formed from a ceramic titanate PTC electrical resistance material which will generate heat in response to the flow of electric current therethrough, said heater having a surface portion through which heat is to be transferred and through which electrical current will flow;
  • a metal body which is to be heated and which has a thermally and electrically conductive surface portion substantially matching in shape with that of the heater surface portion and to which heat is to be transferred from said heater, said body having a thermal coefficient of expansion differing from that of the heater resistance material;
  • said layer comprising a mixture of small electrically and thermally conductive particles selected from the group of silver, silver-copper alloys and graphite materials dispersed throughout a material selected from the group consisting of silicone resin, polyimide resin, benzophenone resin, polyamideimide resins, polybenzimidazole resins, polybenzothiazole resins, polyethyleneimine resins, phosphonitrilic resins and polyester resins so that said layer is flexible, elastic and creep-resistant and stable at temperatures on the order of at least C. and free of components which tend to degrade the PTC heater material.
  • said resin material is selected from the group consisting of silicone resin and polyimide resin and wherein said conductive particles comprise from 60 to 85 percent of the weight of said bonding layer and have an average particle size of about 1 micron.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Ceramic Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Resistance Heating (AREA)
  • Means For Warming Up And Starting Carburetors (AREA)
  • Thermistors And Varistors (AREA)
US428180A 1973-12-26 1973-12-26 PTC heater assembly bonding Expired - Lifetime US3898422A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US428180A US3898422A (en) 1973-12-26 1973-12-26 PTC heater assembly bonding
GB5334374A GB1468720A (en) 1973-12-26 1974-12-10 Ptc heater assemblies
IT54486/74A IT1024412B (it) 1973-12-26 1974-12-11 Perfezionamento nei sistemi di fissaggio di elementi riscaldatori elettrici a coefficiente positivo di temperatura
CA215,925A CA1024202A (en) 1973-12-26 1974-12-13 Ptc heater assembly bonding
DE19742459664 DE2459664B2 (de) 1973-12-26 1974-12-17 Heizvorrichtung
JP49146262A JPS5096944A (enrdf_load_stackoverflow) 1973-12-26 1974-12-19
FR7442280A FR2256621B1 (enrdf_load_stackoverflow) 1973-12-26 1974-12-20

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US428180A US3898422A (en) 1973-12-26 1973-12-26 PTC heater assembly bonding

Publications (1)

Publication Number Publication Date
US3898422A true US3898422A (en) 1975-08-05

Family

ID=23697868

Family Applications (1)

Application Number Title Priority Date Filing Date
US428180A Expired - Lifetime US3898422A (en) 1973-12-26 1973-12-26 PTC heater assembly bonding

Country Status (7)

Country Link
US (1) US3898422A (enrdf_load_stackoverflow)
JP (1) JPS5096944A (enrdf_load_stackoverflow)
CA (1) CA1024202A (enrdf_load_stackoverflow)
DE (1) DE2459664B2 (enrdf_load_stackoverflow)
FR (1) FR2256621B1 (enrdf_load_stackoverflow)
GB (1) GB1468720A (enrdf_load_stackoverflow)
IT (1) IT1024412B (enrdf_load_stackoverflow)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4007720A (en) * 1974-07-30 1977-02-15 Robert Bosch G.M.B.H. Fuel metering system for internal combustion engines
US4096837A (en) * 1975-12-16 1978-06-27 Honda Giken Kogyo Kabushiki Kaisha Automatic choking device of electric heating type
US4204273A (en) * 1977-01-31 1980-05-20 Goldberg Gerald M Construction of illuminating ribbon of light bulbs
US4246880A (en) * 1978-08-23 1981-01-27 Pierburg Gmbh & Co. Kg Arrangement for heating the intake pipe of a spark-ignited internal combustion engine
US4347826A (en) * 1979-10-31 1982-09-07 Nippon Soken, Inc. Fuel evaporator for internal combustion engine
US4356804A (en) * 1979-08-17 1982-11-02 Nippon Soken, Inc. Fuel evaporator
US4357590A (en) * 1979-08-28 1982-11-02 U.S. Philips Corporation Composite thermistor component
US4368380A (en) * 1979-10-26 1983-01-11 Nippon Soken, Inc. Flexible ceramic PTC electric heater assembly
US4709134A (en) * 1984-11-02 1987-11-24 Dr. Ing. H.C.F. Porsche Aktiengesellschaft Antifogging device for a display glass of an indicating instrument
US4899032A (en) * 1987-03-12 1990-02-06 Siemens Aktiengesellschaft Electric heating element utilizing ceramic PTC resistors for heating flooring media
US4960634A (en) * 1990-03-14 1990-10-02 International Business Machines Corporation Epoxy composition of increased thermal conductivity and use thereof
US5028984A (en) * 1988-11-04 1991-07-02 International Business Machines Corporation Epoxy composition and use thereof
US5095413A (en) * 1988-09-22 1992-03-10 Goldberg Gerald M Electric lamp assembly and method
US6285005B1 (en) * 1998-04-09 2001-09-04 Lucent Technologies Inc. Device for housing communication and electronic equipment using positive temperature coefficient material
US20030087448A1 (en) * 2001-11-07 2003-05-08 Hitachi, Ltd Electronic device and thermal type flow meter on vehicle
US20040256491A1 (en) * 2003-05-21 2004-12-23 Rehau Ag & Co. Nozzle body for a cleaning system on a motor vehicle
US20050027055A1 (en) * 2003-07-29 2005-02-03 Intel Corporation Reworkable thermal interface material
JP2011189190A (ja) * 2011-06-20 2011-09-29 Jms Co Ltd 接触型加熱装置
US20180094434A1 (en) * 2015-06-16 2018-04-05 Henkel Ag & Co. Kgaa Printed heater elements integrated in construction materials

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2625561B2 (de) * 1976-06-05 1980-02-21 Behr-Thomson Dehnstoffregler Gmbh, 7014 Kornwestheim Regelkreis zur Durchflußregelung eines flüssigen oder gasförmigen Mediums
JPS5823082B2 (ja) * 1976-11-30 1983-05-13 松下電工株式会社 ヒ−タ
US4177443A (en) * 1978-03-31 1979-12-04 Essex Group, Inc. Thermal relay and electric range control utilizing the same
DE2943922A1 (de) * 1979-10-31 1981-05-14 Ego Elektro Blanc & Fischer Temperaturmelder zur anzeige des temperaturzustandes einer glaskeramik-kochflaeche
DE3023644C2 (de) * 1980-06-24 1983-06-30 Siemens AG, 1000 Berlin und 8000 München Gehäuse für einen elektrischen keramischen Kaltleiter zum Verdampfen von chemischen Desinfektions- und/oder Insektizidsubstanzen
DE3121025A1 (de) * 1981-05-27 1982-12-23 Gustav Wahler Gmbh U. Co, 7300 Esslingen Elektrische heizvorrichtung fuer saugrohre von brennkraftmaschinen
NL8601460A (nl) * 1986-06-05 1988-01-04 Texas Instruments Holland Inlaatspruitstuk van een verbrandingsmotor en voor dat spruitstuk bedoelde verwarmingsinrichting.
KR100191838B1 (ko) * 1994-12-21 1999-06-15 추 내연 기관의 냉매 순환계용 서모스탯 밸브
FR2913255B1 (fr) * 2007-03-02 2009-05-15 Dauphinoise Thomson Sas Soc Pa Procede de fabrication d'un actionneur a verin thermique et actionneur a verin thermique.
DE202017001454U1 (de) 2017-03-19 2017-06-22 Dynamic Solar Systems Ag Geregelte, gedruckte Heizung

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3056750A (en) * 1961-01-23 1962-10-02 Air Reduction Resin bonded electrical resistors and methods of producing the same
US3576387A (en) * 1970-03-19 1971-04-27 Chomerics Inc Heat shrinkable electromagnetic shield for electrical conductors
US3636311A (en) * 1969-11-21 1972-01-18 Robert Hugo Steger Heating devices for vehicle windows
US3645509A (en) * 1970-05-25 1972-02-29 Gen Motors Corp Idle air control
US3673121A (en) * 1970-01-27 1972-06-27 Texas Instruments Inc Process for making conductive polymers and resulting compositions
US3699937A (en) * 1971-08-04 1972-10-24 Peter S De Petris Solid state controlled automatic choke
US3740040A (en) * 1971-10-07 1973-06-19 Gen Motors Corp Carburetor with power choke
US3752133A (en) * 1972-11-15 1973-08-14 Ford Motor Co Multiple heat automatic choke

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4317207Y1 (enrdf_load_stackoverflow) * 1965-03-05 1968-07-17
JPS4317710Y1 (enrdf_load_stackoverflow) * 1965-09-07 1968-07-23

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3056750A (en) * 1961-01-23 1962-10-02 Air Reduction Resin bonded electrical resistors and methods of producing the same
US3636311A (en) * 1969-11-21 1972-01-18 Robert Hugo Steger Heating devices for vehicle windows
US3673121A (en) * 1970-01-27 1972-06-27 Texas Instruments Inc Process for making conductive polymers and resulting compositions
US3576387A (en) * 1970-03-19 1971-04-27 Chomerics Inc Heat shrinkable electromagnetic shield for electrical conductors
US3645509A (en) * 1970-05-25 1972-02-29 Gen Motors Corp Idle air control
US3699937A (en) * 1971-08-04 1972-10-24 Peter S De Petris Solid state controlled automatic choke
US3740040A (en) * 1971-10-07 1973-06-19 Gen Motors Corp Carburetor with power choke
US3752133A (en) * 1972-11-15 1973-08-14 Ford Motor Co Multiple heat automatic choke

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4007720A (en) * 1974-07-30 1977-02-15 Robert Bosch G.M.B.H. Fuel metering system for internal combustion engines
US4096837A (en) * 1975-12-16 1978-06-27 Honda Giken Kogyo Kabushiki Kaisha Automatic choking device of electric heating type
US4204273A (en) * 1977-01-31 1980-05-20 Goldberg Gerald M Construction of illuminating ribbon of light bulbs
US4246880A (en) * 1978-08-23 1981-01-27 Pierburg Gmbh & Co. Kg Arrangement for heating the intake pipe of a spark-ignited internal combustion engine
US4356804A (en) * 1979-08-17 1982-11-02 Nippon Soken, Inc. Fuel evaporator
US4357590A (en) * 1979-08-28 1982-11-02 U.S. Philips Corporation Composite thermistor component
US4368380A (en) * 1979-10-26 1983-01-11 Nippon Soken, Inc. Flexible ceramic PTC electric heater assembly
US4347826A (en) * 1979-10-31 1982-09-07 Nippon Soken, Inc. Fuel evaporator for internal combustion engine
US4709134A (en) * 1984-11-02 1987-11-24 Dr. Ing. H.C.F. Porsche Aktiengesellschaft Antifogging device for a display glass of an indicating instrument
US4899032A (en) * 1987-03-12 1990-02-06 Siemens Aktiengesellschaft Electric heating element utilizing ceramic PTC resistors for heating flooring media
US5095413A (en) * 1988-09-22 1992-03-10 Goldberg Gerald M Electric lamp assembly and method
US5028984A (en) * 1988-11-04 1991-07-02 International Business Machines Corporation Epoxy composition and use thereof
US4960634A (en) * 1990-03-14 1990-10-02 International Business Machines Corporation Epoxy composition of increased thermal conductivity and use thereof
US6285005B1 (en) * 1998-04-09 2001-09-04 Lucent Technologies Inc. Device for housing communication and electronic equipment using positive temperature coefficient material
US20030087448A1 (en) * 2001-11-07 2003-05-08 Hitachi, Ltd Electronic device and thermal type flow meter on vehicle
US7255837B2 (en) * 2001-11-07 2007-08-14 Hitachi, Ltd. Electronic device and thermal type flow meter on vehicle
US20040256491A1 (en) * 2003-05-21 2004-12-23 Rehau Ag & Co. Nozzle body for a cleaning system on a motor vehicle
US7311268B2 (en) * 2003-05-21 2007-12-25 Rehau Ag & Co. Nozzle body for a cleaning system on a motor vehicle
US20050027055A1 (en) * 2003-07-29 2005-02-03 Intel Corporation Reworkable thermal interface material
JP2011189190A (ja) * 2011-06-20 2011-09-29 Jms Co Ltd 接触型加熱装置
US20180094434A1 (en) * 2015-06-16 2018-04-05 Henkel Ag & Co. Kgaa Printed heater elements integrated in construction materials
US12371904B2 (en) * 2015-06-16 2025-07-29 E2Ip Technologies Inc. Printed heater elements integrated in construction materials

Also Published As

Publication number Publication date
FR2256621A1 (enrdf_load_stackoverflow) 1975-07-25
JPS5096944A (enrdf_load_stackoverflow) 1975-08-01
IT1024412B (it) 1978-06-20
FR2256621B1 (enrdf_load_stackoverflow) 1976-10-22
DE2459664B2 (de) 1978-02-09
GB1468720A (en) 1977-03-30
CA1024202A (en) 1978-01-10
DE2459664A1 (de) 1975-07-03

Similar Documents

Publication Publication Date Title
US3898422A (en) PTC heater assembly bonding
US3835434A (en) Ptc resistor package
US6300859B1 (en) Circuit protection devices
EP1911047B1 (en) Circuit protection device having thermally coupled mov overvoltage element and pptc overcurrent element
US3885129A (en) Positive temperature coefficient resistor heater
US4635026A (en) PTC resistor device
US3584190A (en) Self-regulating heat applicator
US5233325A (en) Thermostat with filmy heater
US3958208A (en) Ceramic impedance device
CN113381086B (zh) 一种锂电池过热保护系统及方法
JPS6166391A (ja) 自己温度制御型発熱装置
US6946789B2 (en) EL sheet with bent leg connectors
KR100840796B1 (ko) 세라믹 발열체용 단자
US2686244A (en) Electrical attachnent of temperature sensing devices and the like
TWI689962B (zh) 保護元件
JP2663935B2 (ja) 板状セラミックヒータ及びその製造方法
US3295090A (en) Electrical resistor having a core element with high heat dissipating properties
JPH04112048A (ja) サーマルヘッド
JP2511538B2 (ja) 半導体感温素子
JPH06302405A (ja) 正特性サーミスタ装置
JPH0529069A (ja) 板状ヒーターおよびその製造方法
JPH0945504A (ja) Ｐｔｃサーミスタおよびこれを用いたヒーター構造
JP3278070B2 (ja) 正特性サーミスタ装置
JPH019069Y2 (enrdf_load_stackoverflow)
KR20160014443A (ko) Ｐｔｃ 구조체