Abstract: Functional elements, particularly PTC heating elements, are braced in a hollow reception means, such as a profile tube. The reception means have two at least partly concave top wall areas facing one anther and flat sides of the functional elements and in this way permits a bracing of the functional elements, in that side walls of the reception means, extending substantially perpendicular to the concave top wall areas, are subject to the action of a pressing pressure. In the free space areas defined by the concave top walls can be fitted ends of attachment parts, such as metal lamellas, which are clamped in the same operation, according to the invention, during the bracing of the functional elements. This makes it possible in a simple manner to manufacture assembled devices, particularly electric heating devices.

Abstract: A self-hold motor protector (10) has an open metallic housing (12) in which a thermostatic disc (14) carrying a movable electrical contact (18) is cantilever mounted. A heater seat plate (20) is mounted in the housing in electrical and thermal relationship therewith. The heater seat plate has a seating recess (20a) in which a positive temperature coefficient resistor heating element (22) is received with one contact surface in electrical and thermal engagement with the heater seat plate. A terminal plate (26) mounts a stationary electrical contact (28) and is received over the opening of the housing but electrically isolated therefrom by a gasket (24). An electrically conductive spring (30) extends between the terminal plate and a second contact surface of the heating element.

Abstract: An electric heating module includes an electric heater (10), a heat pipe (20) having an evaporating section (22) thermally attached to the electric heater and a condensing section (24), and at least one heat radiator (30, 40) thermally attached to the condensing section. The electric heater includes a pair of electrode plates (12, 14) and a heating element (16) sandwiched between and electrically connecting the electrode plates. An insulation frame (19) encloses the electrode plates therein for electrically insulating the electric heater from the heat radiator. For the non-linear PTC heating element, the electric heater can rapidly heat up to and stay at a desired stable temperature. The heat pipe can transfer heat from the electric heater to the heat radiator rapidly and timely by phase change.

Abstract: A controller adapted to control the temperature of a heating elements with a wide range of positive temperature coefficient of resistance, including very low values, using a sensor in line with the heating element. The controller is able to take account of non-constant mains power supplies and variation in the element resistance over time.

Abstract: An electric heating element is provided with a durable PTC resistance made at least partially of an iron-based alloy, exhibiting stable characteristics to a temperature of 1500 DEG C. and having a resistance/temperature characteristic curve which substantially increases in a linear manner within a temperature range between an ambient temperature and 1500 DEG C. and can be used for a temperature control. The PCT resistance is provided with an oxidation resistant metallization or is gas-tightly enveloped by a jacket (2, 3, 12), a space between the jacket (2, 3, 12) and the PCT resistance (1,13) being filled with a powder or granules (14) which remove an important gas amount from the space.

Abstract: An apparatus for the independent control of the amount of heat produced by a right and a left side heated hand grip includes a control panel with various input buttons and a pair of LEDS that each indicates a relative power setting of one of the heated hand grips. A microprocessor receives input instructions from the input buttons and provides a first pulsed DC output having a desired duty cycle to one of the heated hand grips and a second pulsed DC output having either the same or a different duty cycle to a remaining one of the heated hand grips, thereby controlling the amount of heat produced by each respective heated hand grip. This improves comfort. Reverse polarity protection, a return to previous power settings, including a remembrance of a differential between the two heated hand grips, and automatic shutoff when battery voltage reaches a predetermined value are described.

Abstract: A heating structure and its temperature control method having therein a heat generating line and a controller. The heat generating line includes a PTC element and a short circuit line serially connected having an insulating fusible layer separating them. When a user sets a heating temperature, electric current is conducted to heat the PTC element, alternative string wave signals input into an AC phase shaping circuit and an AC phase delay shaping circuit are converted into square wave signals; and by measuring with a microprocessor at a given time the phase shift between the two phase shaping circuits to control the switch of a trigger circuit, the PTC element can keep on heating or reduce its temperature to therefore keep the heat generating line at a predetermined working temperature. The structure is applicable to heat generating devices such as electric ovens and heating blankets etc.

Abstract: A device and method for diagnosing shorts and fault conditions in electrical circuits such as heating, ventilation, and air conditioning (HVAC) control circuits. The device includes a positive temperature coefficient (PTC) member to protect the electrical circuit from overcurrent conditions during diagnosis. The device also includes a light emitting diode (LED) and resistor electrically connected in parallel across the PTC member. An overcurrent condition causes the resistance of the PTC member to rise dramatically, creating a potential difference across the PTC member and lighting the LED. The invention also includes a method for locating a short in an HVAC control circuit using the short locating device.

Abstract: An improved variable resistor at least partially compensates for non-linearities in an electrical circuit containing a heating element, for example, a thin-film heating element. A controllable heater includes a heating element, a voltage source (for example, a standard AC electrical outlet) coupled to the heating element, and a variable resistor coupled to the heating element and voltage source. The variable resistor includes a fixed resistive element (for example, one or more thin-film resistors) and a moveable element such as a slider control. The moveable element adjustably contacts the fixed resistive element at a contact point associated with the position such that the variable resistor has a resistance that is at least partially non-linearly related to the position, but wherein the heating element has a dissipated power that is at least partially linearly related to the position of the variable resistor.

Abstract: The present invention relates to an electric warmer for heating a container by means of a heat transfer medium. The warmer comprises a jar into which the container can be inserted for heating, and an electric heating device comprising at least one resistance heating element for heating the heat transfer medium.

Abstract: A radiant electric heater (2) is arranged for location underneath and against a cooking plate (12) and incorporates a heating element (14) spaced from the cooking plate and a temperature sensor assembly (26). The temperature sensor assembly (26) comprises a beam (28) of ceramic material provided within the heater and extending at least partially across the heater over the at least one heating element (14). The beam (28) has a substantially planar upper surface (32) arranged to face the cooking plate (12), in contact with the cooking plate or in close proximity to it, and an under surface (34) arranged for exposure to direct radiation from the heating element (14). Provided on the planar upper surface (32) is an electrical component (36), such as of film or foil form, having an electrical parameter which changes as a function of temperature of the cooking plate.

Abstract: A power control system for an electric cooktop. The power level is set by a knob connected to a potentiometer. Potentiometer information is digitally communicated by a controller over a serial communication bus to a power unit. The power unit communicates power level display information back to the controller over the same serial communication bus. The display information is displayed as numbers on a digital display by the controller. The power unit controls a heating element of the cooktop according to the potentiometer information. A second potentiometer can be added to control a second heating element by operating as a slave to the first controller. Further, multiple heating elements can be controlled by a single potentiometer by dividing the angular rotation into multiple segments or ranges.

Abstract: Heating of a functional unit is started by a control device. An actual temperature or a parameter dependent on the actual temperature is monitored during, and optionally before and after the actual heating of the functional unit. A characteristic feature of the time course of the actual temperature or of the parameters dependent on the heating temperature, which determines the phase transition of water, serves for the evaluation and control of the heating. Analysis of the characteristic features is used to control the heating power of the heating elements. Threshold values and further factors such as proportionality factors for the controller, for example, are determined depending upon significant characteristics. The threshold values and factors are also particularly used for a subsequent starting of the heating using the corresponding analysis and control.

Abstract: A negative temperature coefficient thermistor includes a thermistor element containing a transition metal oxide as a main component; internal electrodes disposed in the thermistor element; and external electrodes, electrically connected to the internal electrodes. A method for manufacturing such a thermistor includes providing green ceramic sheets for forming the thermistor element; applying a conductive paste for forming the internal electrodes onto some of the green ceramic sheets to form internal electrode layers; stacking the green ceramic sheets and the green ceramic sheets with the paste to form a green compact; firing the green compact to obtain a fired compact; and forming the external electrodes.

Abstract: The invention relates to an electrically and thermally conductive adhesive composition for cementing together at least one metallized (e.g. aluminized or silvered) surface of a positive temperature coefficient (PTC) element to at least one metallic (e.g. aluminum) electrode, in the manufacture of PTC thermistor devices which are potentially capable of operating in a working temperature range not less than ?55° C. to +300° C. and for at least 30,000 hours. The composition comprises, as the adhesive component, a curable silicone (e.g. silicone rubber) prepolymer, as well as finely divided silicon carbide and finely-divided silicon, and preferably also a finely-divided metallic powder.

Abstract: An electrically powered resistance heating handgrip includes a control circuit located within a hollow core that fits coaxially within the open end of a handlebar of a motorcycle or snowmobile. The control circuit is mounted on a thin, narrow, elongated printed circuit board and includes a microprocessor that is programmed to contain a lookup table of temperatures. A thermistor provides feedback signals to the microprocessor which compares temperature sensor feedback signals to a target temperature. The target temperature is established by a dial. The dial operates the wiper of a variable potentiometer to establish the target temperature. Heat is uniformly distributed by wrapping the heating element wire thereof about a thermally conductive sheet of aluminum, and encasing the wire within a temperature resistant dielectric sheathing.

Abstract: An electric heating device is adapted to be used in particular as an auxiliary electric heating for motor vehicles. The heating device comprises a plurality of PTC heating elements arranged in a plane of said heating device. The PTC heating elements are in electric contact with contact sheets for supplying current thereto and in thermal contact with radiator elements for transferring the heat produced to an air current to be heated. According to the present invention, the PTC heating elements arranged in this plane are adapted to be controlled separately in at least two groups.

Abstract: An improved variable resistor at least partially compensates for non-linearities in an electrical circuit containing a heating element, for example, a thin-film heating element. A controllable heater includes a heating element, a voltage source (for example, a standard AC electrical outlet) coupled to the heating element, and a variable resistor coupled to the heating element and voltage source. The variable resistor includes a fixed resistive element (for example, one or more thin-film resistors) and a moveable element such as a slider control. The moveable element adjustably contacts the fixed resistive element at a contact point associated with the position such that the variable resistor has a resistance that is at least partially non-linearly related to the position, but wherein the heating element has a dissipated power that is at least partially linearly related to the position of the variable resistor.

Abstract: A heating apparatus includes a central hot plate for heating the center portion of a substrate, a plurality of segment hot plates for heating the peripheral portion of the substrate, a hot plate support member supporting the central hot plate and the segment hot plates, support pins for supporting the substrate so as to face the central hot plate and the segment hot plates in a close proximity without being in contact with the central hot plate and the segment hot plates, and a power supply for supplying electricity to the central hot plate and the segment hot plates.

Abstract: An electric heating device including PTC heating elements which have electrode sheets arranged on both sides thereof. These electrode sheets supply power to the PTC heating elements and each having connected thereto radiator elements for emitting the heat generated by the PTC heating elements. An electrically insulating layer is arranged between at least one of the electrode sheets and the respective radiator element.

Abstract: An electrical device includes a package having an array of connections, a thermally conductive, electrically insulative substrate in the package, a plurality of polymeric positive temperature coefficient (PPTC) resistors in the package in thermal contact with the substrate, and, at least one heating element such as a power field effect transistor in thermal contact with the substrate, for indirectly heating the PPTC resistors in response to a control current, thereby to trip the PPTC resistors from a low resistance state to a very high resistance state. A method for controlling a plurality of electrical loads is also disclosed.

Abstract: An electrical device includes a package having an array of connections, a thermally conductive, electrically insulative substrate in the package, a plurality of polymeric positive temperature coefficient (PPTC) resistors in the package in thermal contact with the substrate, and, at least one heating element such as a power field effect transistor in thermal contact with the substrate, for indirectly heating the PPTC resistors in response to a control current, thereby to trip the PPTC resistors from a low resistance state to a very high resistance state. A method for controlling a plurality of electrical loads is also disclosed.

Abstract: An electric heating device including PTC heating elements which have electrode sheets arranged on both sides thereof. These electrode sheets supply power to the PTC heating elements and each having connected thereto radiator elements for emitting the heat generated by the PTC heating elements. An electrically insulating layer is arranged between at least one of the electrode sheets and the respective radiator element.

Abstract: A method and apparatus for providing an indication of the composition of an examined fluid by using an electrical resistor, particularly a positive temperature coefficient thermistor, for measuring the thermal conductivity of the examined fluid with the known thermal conductivity of different fluid compositions. The method and apparatus are particularly described for indicating the relative proportions of a working fluid in the liquid and vapor phases in one or more stages of a heat pump. Another described application is for indicating the liquid level in a liquid vaporizer.

Abstract: An electrical heater having a plurality electrodes disposed adjacently on a substrate in spaced apart relation and interconnected by a thermistor material, for example a positive temperature coefficient material. The electrodes each have at least one end portion and preferably two opposite end portions coupled to corresponding electrical terminal located at a common termination zone on the substrate. A spacing between adjacent electrodes may vary and adjacent electrodes may include interdigitated portions to vary the heat produced on select portions of the substrate.

Abstract: There is disclosed a heat sink for a PTC heating element, which heat sink including a first end, a second end, and a pair of webs extending from the second end towards the first end, in which each of the webs is connected to the cover face via a respective curved section, and the curved section is inward of the respective web.

Abstract: On the one hand is provided an electric heating element (15, 31) consisting of a semiconducting ceramic (28, 32) as well as a method for its production. The semiconducting ceramic material may be porous or foamed to thus contain pores (29, 34) open outwardly. The pores are attainable by admixing filler bodies, which dissolve during sintering, to the starting material or by impreganting a textile substrate material (36) with a ceramic material. Due to the porosity of the heating element (15, 31) an increased radiant surface area is attained. On the other hand is provided an electric heating element (115, 132, 145, 150, 158, 160, 162) as well as a method for its production which consists of semiconducting ceramic and comprises a negative temperature coefficient of the electrical resistance. The temperature coefficient is negative throughout over the full operating temperature range. The material suitable for the heating element (115, 132, 145, 150, 158, 160, 162) is doped silicon carbide or TiN.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with a high voltage capability and improved electrical stability. The polymeric PTC compositions are readily blended and generally do not require cross-linking, particularly radiation induced cross-linking in order to manufacture useful products.

Abstract: An adaptive temperature control circuit includes a first circuit for producing an error signal representing the difference between a preset temperature and an actual temperature and a second circuit coupled to the first circuit for producing a pulse width modulated output signal having a frequency greater than one hertz, wherein the width of the pulses is proportional to the error signal.

Abstract: Use of PTC circuit protection devices in motor vehicle wiring systems. The devices can replace some or all of the fuses conventionally used. Preferred devices contain PTC conductive polymers. Because the PTC devices can be reset without physical access to them, the wiring system can be arranged more efficiently and more economically. For example, the size of at least some of the wires of the harness can in many case be reduced.

Abstract: An electrical resistance or heater includes an electrical resistive track provided on an insulating substrate. Two predetermined sections of the track have a predetermined current carrying capacity and are bridged by a glass, ceramic, or glass ceramic material. The configuration of the track and the glass material are such that at a predetermined temperature, the leakage current between the track sections rises to the extent that it causes a current to flow through one or both of the sections which is substantially above its current carrying capability, whereby one section fails.

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.

Abstract: A heat-exchanging core portion includes a plurality of tubes arranged in parallel and a plurality of fin members disposed between a pair of adjacent tubes. While an electric heat emitting unit is constructed by supporting a heat emitting body including a heat emitting element inside a frame through a fin member. The electric heat emitting unit is installed into a space, which is defined in the heat-exchanging core portion, having a predetermined distance after the heat-exchanging core portion is assembled and integrally brazed while defining the space.

Abstract: A novel multi-layer current limiting PTC polymer device comprising at least two layers of a conductive polymer composition with electrodes attached thereto characterized by having a low contact resistance and a method of producing the same. The invention provides for the selective treatment of portions of the surface of each layer of the conductive polymer composition by at least one of plasma/corona etching and plasma sputtering/plasma spray to create a site for attachment of the electrodes resulting in a low contact resistance. The electrical devices of the invention are particularly useful in circuit protection applications.

Abstract: The invention is directed to a positive temperature coefficient heater. A pair of electrical conductors are connected to a positive temperature coefficient body at respective locations. A dielectric material is attached to the body between the conductors and prevents electrical arcing around the body between the conductors.

Abstract: The present invention generally relates to use of constant current power supply to control temperatures of a device to plural Curie temperatures, without sacrificing the precision and uniformity of temperature achieved in the known devices. In accordance with exemplary embodiments, multiple layers of alloy having different Curie temperatures are separately accessed as an outer most layer is heated through its Curie point. Power to the device can be controlled by varying a frequency of circulating current and by searching to identify a layer of Curie point material which provides heating at a temperature accurately controlled to a fixed value, where any one of a number of different such temperatures may be selected.

Abstract: An electrical heating device employing positive temperature coefficient (PTC) thermistors as heating elements, which provides direct contact between the thermistor heating elements and the radiation units on both sides with no intervening members and which also provides the electrical current to the heating elements via the radiation units.

Abstract: A novel current limiting PTC polymer device comprising a conductive polymer composition with electrodes attached thereto characterized by having a low contact resistance and a method of producing the same. The invention provides for the selective treatment of portions of the surface of the conductive polymer composition by at least one of plasma/corona etching and plasma sputtering/plasma spray to create a site for attachment of the electrodes resulting in a low contact resistance. The electrical devices of the invention are particularly useful in circuit protection applications.

Abstract: A heater unit 1 has a plurality of flat heaters 11 adjacently arranged side by side and having common upper and lower surfaces. The thickness T of the heaters 11 is substantially uniform. Each heater 11 has an adjacent end surface 111 which faces toward an adjacent end surface 111 of the adjacent heater 11. The heater unit 1 also has upper and lower electrodes 21 holding the heaters 11 and respectively attached to the upper and lower surfaces of the heaters 11. The adjacent end surfaces 111 of the heaters 11 adjoining each other, and the upper and lower electrodes 21 form an air gap 12 therebetween. The creepage distance L along each adjacent end surface 111 is larger than the thickness T of the heaters 11. The dielectric strength of the heater unit 1 depends on the creepage distance L. The thickness T of the heaters 11 can be decreased without decreasing the dielectric strength of the heater unit 1. The output of the heater unit 1 increases when the thickness T is decreased.

Abstract: An electrical assembly (10) comprising a first electrical device (12) comprised of a non-linear resistant, temperature responsive element (14) and first and second electrodes (16,18), the device (12) being connectable to a first power supply (20) such that a first electrical current (i.sub.1) travels through the resistive element (14) from the first electrode (16) to the second electrode (18). A second electrical circuit (24) is in electrical contact with the electrical device (12) such that the second circuit (24) may introduce a secondary electrical current (i.sub.2) into a localized portion of the non-linear resistant element (14), the second current (i.sub.2), when applied to the non-linear resistant element (14), causes the element (14) to change from a first resistant state to a second resistant state.

Abstract: An electronic selector knob circuit (10) which uses a tapped potentiometer (POT1) to provide accurate operation without requiring factory calibration. The potentiometer (POT1) is calibrated through on-board circuitry which includes a tap voltage biasing device and which monitors operation on a continual basis through both a current monitor (16) and a voltage monitor (18). A redundant disable circuit (14) provides a redundant hardware means for shutting off all oven heating elements.

Abstract: An internal heater for a fuel injector includes an array of plates of a positive temperature coefficient (PTC) material arranged about the valve element in a square tube shape, and surrounded by a heat insulating polytetrafluorethylene sleeve. The plates are preferably coated with polyimide to be protected from the fuel which flows over both surfaces of the plates. Electrical connections are established by inner and outer bands attached to the plates, with a conductive disc having tabs extending to the bands. Spring-loaded contact pins located radially outward from a seal on the disc have wires extending to the connector body contacts of the injector.

Abstract: A solenoid trip unit is electrically connected in parallel with a current limiting polymer element in series with circuit breaker contacts to function as a shunt resistance for the polymer element, becoming energized by transition of the polymer element to its high resistive state, for tripping the breaker contacts open upon such transition. The solenoid may be particularly wound with a resistive wire.

Abstract: An electric heating device includes a plurality of heating elements which are assembled to form a block. Such a heating element is formed from two metal plates, with the interposition of PTC elements. In order to increase the heat transfer, the metal plates are provided with corrugation ribs. Each heating element includes a pair of metal plates which are angled off essentially in the form of an L such that the angled-off sections are connected in a frictionally locking manner to each other. The angled-off sections are arranged at opposite ends of the heating elements and angled in opposite directions, the length of the angled-off sections of the metal plates being dimensioned such that angled-off sections of one pair of metal plates are in mutual abutment with angled-off sections of respectively adjacent pairs of metal plates.

Abstract: A heating device for heating an item such as a carburetor uses a first PTC heating element 12 positioned compactly within a housing 10 which is directly adjacent the item to be heated. A Second PTC element 14 having a great electrical resistance increase at a prescribed temperature level is also compactly contained in the housing and is electrically connected in series to the first PTC element 12. This second PTC element 14 restricts the electric current flow through the device when the ambient temperature exceeds the prescribed temperature level.

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.

Abstract: A heating and ventilating apparatus for a motor vehicle having either an internal combustion engine or an electric propulsion motor, where the heat given off by the engine or motor is insufficient to provide heating requirements for the cabin of the vehicle under all conditions, comprises an air inlet chamber associated with a blower, and an air outlet chamber which feeds at least one outlet duct, leading to the cabin. A heating branch is interposed between the inlet chamber and the outlet chamber, with heating means arranged in the air heating branch. The heating means comprise a radiant heater having pure or passive resistance, together with a radiant electric heater having a positive temperature co-efficient resistance, the two heaters being connected electrically in series in a circuit which is supplied by a voltage source.

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.

Abstract: A parallel, zone-type heating cable wherein thermally-controlled ferrite reed switches in each zone regulate current flow to heating elements aligned in parallel with each other. Two parallel conductors deliver current to the switches and the heating elements. A dielectric insulation material separates the conductors from each other and the heating elements. The heating cable may further include a component having a particular temperature coefficient of resistance aligned in parallel with the switch to further regulate current flow to a positive but lesser level when the switch is open.

Abstract: The invention provides polymeric PTC compositions and electrical PTC devices with a high voltage capability and improved electrical stability. The polymeric PTC compositions are readily blended and generally do not require cross-linking, particularly radiation induced cross-linking in order to manufacture useful products.