A food delivery system comprising an induction heating apparatus, an induction-heatable apparatus, and a food delivery cart. The induction heating apparatus includes an induction heating element and an electronic system including a communication element configured to communicatively link to an ordering system. The induction-heatable apparatus is configured to be heated via the induction heating apparatus and includes an RFID tag configured to store information of food being heated and information of an intended recipient or intended destination of the food. The food delivery cart includes an induction heating element configured to warm the induction-heatable apparatus and hence the food and an electronic system including an RFID reader to determine information corresponding to the food, augment the information, and transmit the augmented information a central monitoring system.
A47J 39/00 - Heat-insulated warming chambersCupboards with heating arrangements for warming kitchen utensils
A47J 36/32 - Time-controlled igniting mechanisms or alarm devices
F28D 20/02 - Heat storage plants or apparatus in generalRegenerative heat-exchange apparatus not covered by groups or using latent heat
G06K 7/10 - Methods or arrangements for sensing record carriers by electromagnetic radiation, e.g. optical sensingMethods or arrangements for sensing record carriers by corpuscular radiation
G06K 19/07 - Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards with integrated circuit chips
IN-SITU MONITORING AND CONTROL OF INDUCTION WELDING OF THERMOPLASTIC COMPOSITES USING AMORPHOUS OR NANOCRYSTALLINE MICROWIRE TEMPERATURE SENSORS AND SELF-CENTERING ANTENNAE RAIL SYSTEM
A thermoplastic composite welding microwire temperature measurement system broadly comprises a plurality of moveable antennae configured to transmit interrogation signals, a rail system including a motorized linear stage configured to move the antennae along a weld line, and a reader or processor configured to determine a position of the microwire temperature sensor and determine a welding temperature based on response signals of the sensor. The interrogation signal corresponds to two different maximum ramp current amplitudes to create two re-magnetization pulses non-overlapping in the time domain.
B29C 65/00 - Joining of preformed partsApparatus therefor
H01Q 1/00 - Details of, or arrangements associated with, antennas
B29C 65/36 - Joining of preformed partsApparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction
In-situ monitoring and control of induction welding of thermoplastic composites using amorphous or nanocrystalline microwire temperature sensors and self-centering antennae rail system
A thermoplastic composite welding microwire temperature measurement system broadly comprises a plurality of moveable antennae configured to transmit interrogation signals, a rail system including a motorized linear stage configured to move the antennae along a weld line, and a reader or processor configured to determine a position of the microwire temperature sensor and determine a welding temperature based on response signals of the sensor. The interrogation signal corresponds to two different maximum ramp current amplitudes to create two re-magnetization pulses non-overlapping in the time domain.
A food delivery system comprising an induction heating apparatus, an induction-heatable apparatus, and a food delivery cart. The induction heating apparatus includes an induction heating element and an electronic system including a communication element configured to communicatively link to an ordering system. The induction-heatable apparatus is configured to be heated via the induction heating apparatus and includes an RFID tag configured to store information of food being heated and information of an intended recipient or intended destination of the food. The food delivery cart includes an induction heating element configured to warm the induction-heatable apparatus and hence the food and an electronic system including an RFID reader to determine information corresponding to the food, augment the information, and transmit the augmented information a central monitoring system.
A47J 36/32 - Time-controlled igniting mechanisms or alarm devices
G06K 7/10 - Methods or arrangements for sensing record carriers by electromagnetic radiation, e.g. optical sensingMethods or arrangements for sensing record carriers by corpuscular radiation
G06K 19/07 - Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards with integrated circuit chips
G06Q 10/08 - Logistics, e.g. warehousing, loading or distributionInventory or stock management
5.
Temperature measurement system employing an electromagnetic transponder and separate impedance-changing parasitic antenna
a), while the interrogator (24) has a transmitter (42) and antenna (40). The sensor (22) is designed to be placed in thermal contact with an object to be temperature-measured, with the interrogator (24) placed in proximity to the object. The systems (20) may be used with food servingware domes (88, 114), which can be preheated and placed over a food-bearing plate to maintain the temperature of the food.
H05B 6/06 - Control, e.g. of temperature, of power
G01K 1/024 - Means for indicating or recording specially adapted for thermometers for remote indication
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
Temperature measurement systems (20) include a temperature sensor (22) and an electronic signal interrogator (24). The temperature sensor (22) has a transponder (26) equipped with an antenna (28), and a separate parasitic antenna (32) with a temperatures sensitive transducer (34, 68-74, 78a-84a), while the interrogator (24) has a transmitter (42) and antenna (40). The sensor (22) is designed to be placed in thermal contact with an object to be temperature-measured, with the interrogator (24) placed in proximity to the object. The systems (20) may be used with food servingware domes (88, 114), which can be preheated and placed over a food-bearing plate to maintain the temperature of the food.
a), while the interrogator (24) has a transmitter (42) and antenna (40). The sensor (22) is designed to be placed in thermal contact with an object to be temperature-measured, with the interrogator (24) placed in proximity to the object. The systems (20) may be used with food servingware domes (88, 114), which can be preheated and placed over a food-bearing plate to maintain the temperature of the food.
H05B 6/06 - Control, e.g. of temperature, of power
G01K 1/02 - Means for indicating or recording specially adapted for thermometers
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
Temperature measurement systems (20) include a temperature sensor (22) and an electronic signal interrogator (24). The temperature sensor (22) has a transponder (26) equipped with an antenna (28), and a separate parasitic antenna (32) with a temperatures sensitive transducer (34, 68-74, 78a-84a), while the interrogator (24) has a transmitter (42) and antenna (40). The sensor (22) is designed to be placed in thermal contact with an object to be temperature-measured, with the interrogator (24) placed in proximity to the object. The systems (20) may be used with food servingware domes (88, 114), which can be preheated and placed over a food-bearing plate to maintain the temperature of the food.
A remote, noncontact temperature determination method and apparatus is provided, which is operable to determine the temperature of a conducting member in operative thermal communication with an object of interest. The method comprises the steps of first inducing a closed vortex eddy current in a conducting member by subjecting the member to a magnetic field, such that the corresponding eddy current magnitude changes exponentially over time. A characteristic time constant of the exponential current magnitude changes is then determined, and this is used to calculate the temperature of the object. The apparatus includes a field transmitting coil coupled with a waveform generator for inducing the eddy current, and a field receiving coil assembly which detects the corresponding induced magnetic. Temperature determinations can be made which are substantially independent of the relative distance and/or angular orientation between the conducting member and the field receiving coil assembly.
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
G01R 33/12 - Measuring magnetic properties of articles or specimens of solids or fluids
An induction heatable article such as a pan is provided having a synthetic resin body with at least one susceptor coil secured to the body and operable under the influence of an induction field to generate Joule heating within the coil to thereby heat the body. The coil has a plurality of zones, each adjacent a different portion of the body and capable of providing respective, different magnitudes of Joule heating-derived energy per unit time in the zones. A multiple-pan, modular food heating/warming table includes a table supporting an array of individually controllable induction heaters with a plurality of synthetic resin, food-holding pans positionable on the table, wherein each pan has a zoned susceptor coil for induction heating of the pans
An induction heatable article such as a pan is provided having a synthetic resin body with at least one susceptor coil secured to the body and operable under the influence of an induction field to generate Joule heating within the coil to thereby heat the body. The coil has a plurality of zones, each adjacent a different portion of the body and capable of providing respective, different magnitudes of Joule heating-derived energy per unit time in the zones. A multiple-pan, modular food heating/warming table includes a table supporting an array of individually controllable induction heaters with a plurality of synthetic resin, food-holding pans positionable on the table, wherein each pan has a zoned susceptor coil for induction heating of the pans.
An induction heatable article such as a pan is provided having a synthetic resin body with at least one susceptor coil secured to the body and operable under the influence of an induction field to generate Joule heating within the coil to thereby heat the body. The coil has a plurality of zones, each adjacent a different portion of the body and capable of providing respective, different magnitudes of Joule heating-derived energy per unit time in the zones. A multiple-pan, modular food heating/warming table includes a table supporting an array of individually controllable induction heaters with a plurality of synthetic resin, food-holding pans positionable on the table, wherein each pan has a zoned susceptor coil for induction heating of the pans
Improved, high-strength micro-thermocouples (10) are provided, which include first and second microwires (12, 14) each preferably in the form of an elongated metallic core (18, 22), with an outer glass coating (20, 24); at least one of the microwires (12, 14) is an amorphous microwire (12), and in preferred forms the other microwire is a crystalline microwire (14). The thermocouple junction (16) is formed by stripping the distal ends of the microwires (12, 14) to provide stripped ends (18a, 22a). The stripped crystalline microwire end (22a) is wrapped about the stripped amorphous microwire end (18a) to form a series of abutting convolutions (30). The micro-thermocouples (10) find particular utility in the fabrication and repair of carbon fiber composite materials, such as airplane components.
Improved, highly accurate microwire sensors (10) include a microwire assembly (14) including at least one primary, temperature-sensing microwire (16) encased within a closed-ended, stress-absorbing protective tube (12). Preferably, the sensor assembly (14) includes a plurality of microwires, e.g., a primary temperature-sensing microwire (16), a reference microwire (18), and a calibration microwire (20). The sensors (10) may be embedded within a heat-treatable or curable material (24) to monitor the temperature of the material (24) over a selected temperature range, e.g., during a pre- and/or post-curing temperature range. The tube (12) is formed of material which does not appreciably magnetically bias the microwire assembly (14), and substantially prevents forces exerted on the tube (12) from distorting the sensor assembly (14).
G01K 7/00 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
G01K 15/00 - Testing or calibrating of thermometers
Improved, highly accurate microwire sensors (10) include a microwire assembly (14) including at least one primary, temperature-sensing microwire (16) encased within a closed-ended, stress-absorbing protective tube (12). Preferably, the sensor assembly (14) includes a plurality of microwires, e.g., a primary temperature-sensing microwire (16), a reference microwire (18), and a calibration microwire (20). The sensors (10) may be embedded within a heat-treatable or curable material (24) to monitor the temperature of the material (24) over a selected temperature range, e.g., during a pre- and/or post-curing temperature range. The tube (12) is formed of material which does not appreciably magnetically bias the microwire assembly (14), and substantially prevents forces exerted on the tube (12) from distorting the sensor assembly (14).
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
G01K 7/38 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils the variations of temperature influencing the magnetic permeability
Improved treatment apparatus (120, 152) is provided for the treatment (e.g., molding, heating and/or curing) of objects such as parts or part precursors (148, 170) including wireless detection of a temperature parameter related to the objects during treatment thereof. The objects include associated microwire-type sensors (150, 174) which have characteristic re-magnetization responses under the influence of applied, alternating magnetic fields. The apparatus (120, 152) have treatment chambers (122, 153) sized to hold the objects to be treated, with one or more antennas (132, 124, 166) proximal to such objects and operable to generate interrogating alternating magnetic fields and to detect the responses of the sensors (150, 174). The detected temperature parameter information is used by an apparatus controller (146) to maintain desired ambient conditions within the treatment chamber (122, 153).
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
B29C 35/02 - Heating or curing, e.g. crosslinking or vulcanising
B29C 73/30 - Apparatus or accessories not otherwise provided for for local pressing or local heating
B29C 73/34 - Apparatus or accessories not otherwise provided for for local pressing or local heating for local heating
F27B 17/00 - Furnaces of a kind not covered by any of groups
G05D 23/26 - Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature the sensing element having a permeability varying with temperature
B29C 35/08 - Heating or curing, e.g. crosslinking or vulcanising by wave energy or particle radiation
A remote, noncontact temperature determination method and apparatus is provided, which is operable to determine the temperature of a conducting member forming a part of or in operative thermal communication with an object of interest. The method comprises the steps of first inducing a closed vortex eddy current (28) in a conducting member (16, 38, 44) by subjecting the member (16, 38, 44) to a magnetic field, such that the corresponding eddy current magnitude changes exponentially over time. A characteristic time constant of the exponential current magnitude changes is then determined, and this is used to calculate the temperature of the object. The apparatus (24) includes a field transmitting coil (14) coupled with a waveform generator (12) for inducing the eddy current (28), and a field receiving coil assembly (18) which detects the corresponding magnetic field induced by the eddy current (28). Using the invention, temperature determinations can be made which are substantially independent of the relative distance and/or angular orientation between the conducting member (16, 38, 44) and the field receiving coil assembly (18).
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
G01K 13/10 - Thermometers specially adapted for specific purposes for measuring temperature within piled or stacked materials
A remote, noncontact temperature determination method and apparatus is provided, which is operable to determine the temperature of a conducting member forming a part of or in operative thermal communication with an object of interest. The method comprises the steps of first inducing a closed vortex eddy current (28) in a conducting member (16, 38, 44) by subjecting the member (16, 38, 44) to a magnetic field, such that the corresponding eddy current magnitude changes exponentially over time. A characteristic time constant of the exponential current magnitude changes is then determined, and this is used to calculate the temperature of the object. The apparatus (24) includes a field transmitting coil (14) coupled with a waveform generator (12) for inducing the eddy current (28), and a field receiving coil assembly (18) which detects the corresponding magnetic field induced by the eddy current (28). Using the invention, temperature determinations can be made which are substantially independent of the relative distance and/or angular orientation between the conducting member (16, 38, 44) and the field receiving coil assembly (18).
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
G01K 13/10 - Thermometers specially adapted for specific purposes for measuring temperature within piled or stacked materials
A remote, noncontact temperature determination method and apparatus is provided, which is operable to determine the temperature of a conducting member forming a part of or in operative thermal communication with an object of interest. The method comprises the steps of first inducing a closed vortex eddy current (28) in a conducting member (16, 38, 44) by subjecting the member (16, 38, 44) to a magnetic field, such that the corresponding eddy current magnitude changes exponentially over time. A characteristic time constant of the exponential current magnitude changes is then determined, and this is used to calculate the temperature of the object. The apparatus (24) includes a field transmitting coil (14) coupled with a waveform generator (12) for inducing the eddy current (28), and a field receiving coil assembly (18) which detects the corresponding magnetic field induced by the eddy current (28). Using the invention, temperature determinations can be made which are substantially independent of the relative distance and/or angular orientation between the conducting member (16, 38, 44) and the field receiving coil assembly (18).
One-time, single-use sensor elements (22, 46) are provided for detecting the occurrence of predetermined conditions such as temperature and elapsed time- temperature. The sensor elements (22, 46) preferably comprise elongated, glass-coated, metal alloy, amorphous or nanocrystalline microwires (30, 48), which can be placed in a position to detect the predetermined condition of interest. An alternating magnetic field detector (28) may be used to continuously or periodically interrogate the sensor elements (22, 46) to determine if the predetermined condition has occurred. In one aspect of the invention, the microwires (30, 48) experience a change in configuration upon the occurrence of the predetermined condition, and have correspondingly different induced remagnetization responses. In another embodiment, a static microwire is provided having an initial bi-stable single domain; when a predetermined time-temperature condition is experienced, multiple domains are established in the microwire, and this can be detected by the detector (28).
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
G01K 1/14 - SupportsFastening devicesArrangements for mounting thermometers in particular locations
G01R 33/00 - Arrangements or instruments for measuring magnetic variables
H01F 1/153 - Amorphous metallic alloys, e.g. glassy metals
H01F 1/12 - Magnets or magnetic bodies characterised by the magnetic materials thereforSelection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
H01B 7/00 - Insulated conductors or cables characterised by their form
C22C 45/04 - Amorphous alloys with nickel or cobalt as the major constituent
One-time, single-use sensor elements (22, 46) are provided for detecting the occurrence of predetermined conditions such as temperature and elapsed time-temperature. The sensor elements (22, 46) preferably comprise elongated, glass-coated, metal alloy, amorphous or nanocrystalline microwires (30, 48), which can be placed in a position to detect the predetermined condition of interest. An alternating magnetic field detector (28) may be used to continuously or periodically interrogate the sensor elements (22, 46) to determine if the predetermined condition has occurred. In one aspect of the invention, the microwires (30, 48) experience a change in configuration upon the occurrence of the predetermined condition, and have correspondingly different induced remagnetization responses. In another embodiment, a static microwire is provided having an initial bi-stable single domain; when a predetermined time-temperature condition is experienced, multiple domains are established in the microwire, and this can be detected by the detector (28).
Improved microwire strain sensor elements (20, 40, 52, 62) and corresponding methods are provided, which permit accurate, wireless strain monitoring of a variety of structures, including composite structures, through use of a remote detector (28). The sensor elements (20, 40, 52, 62) have amorphous or nanocrystalline metallic alloy microwire cores (22, 48), which exhibit substantially reduced remagnetization responses when the sensor elements (20, 40, 52, 62) are coupled with a structure to be strain-monitored, and the structures are in an unstrained condition. When the monitored structure experiences a strain above a pre-selected threshold value, the microwire cores (22, 48) exhibit substantially different remagnetization responses as an indication that the monitored structure has experienced a strain above a strain threshold or over a range of strain. In use, the strain sensor elements (20, 40, 52, 62) are coupled with a structure to be monitored by application of the sensor elements (20, 40, 52, 62) to a surface of the structure, or by imbedding the sensor elements (20, 40, 52, 62) within the structure, and the coupled sensor elements are periodically interrogated by the detector (28). Preferably, the microwire cores (22, 48) are placed in compression in order to suppress the inherent remagnetization responses thereof by means of a surrounding body (26) or surrounding layers (44, 46) formed of synthetic resin material which shrinks upon curing. When the sensor elements (20, 40, 52, 62) are strained as a result of a strain experienced by the monitored structure, the remagnetization responses of the microwire cores (22, 48) are substantially increased.
G01B 7/16 - Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
Improved microwire strain sensor elements (20, 40, 52, 62) and corresponding methods are provided, which permit accurate, wireless strain monitoring of a variety of structures, including composite structures, through use of a remote detector (28). The sensor elements (20, 40, 52, 62) have amorphous or nanocrystalline metallic alloy microwire cores (22, 48), which exhibit substantially reduced remagnetization responses when the sensor elements (20, 40, 52, 62) are coupled with a structure to be strain-monitored, and the structures are in an unstrained condition. When the monitored structure experiences a strain above a pre-selected threshold value, the microwire cores (22, 48) exhibit substantially different remagnetization responses as an indication that the monitored structure has experienced a strain above a strain threshold or over a range of strain. In use, the strain sensor elements (20, 40, 52, 62) are coupled with a structure to be monitored by application of the sensor elements (20, 40, 52, 62) to a surface of the structure, or by imbedding the sensor elements (20, 40, 52, 62) within the structure, and the coupled sensor elements are periodically interrogated by the detector (28). Preferably, the microwire cores (22, 48) are placed in compression in order to suppress the inherent remagnetization responses thereof by means of a surrounding body (26) or surrounding layers (44, 46) formed of synthetic resin material which shrinks upon curing. When the sensor elements (20, 40, 52, 62) are strained as a result of a strain experienced by the monitored structure, the remagnetization responses of the microwire cores (22, 48) are substantially increased.
G01B 7/16 - Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
G01B 7/24 - Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in magnetic properties
The temperature sensors (26,64,96) preferably include a plurality of individual, magnetically susceptible temperature sensor elements (28-34,66,92), as well as optional magnetic field-responsive data elements (38,40,20) adapted for attachment to object (44) or to a substrate (82) in turn attached to object (44). The temperature sensor elements (28-34,66,92) preferably have magnetic bodies (22,70) exhibiting a re-magnetization response under the influence of an applied alternating magnetic field, which is different below and above a set point temperature, normally the Curie temperature of the magnetic body (22) or an adjacent sheath (74,94). The temperature sensors (26,64,96) are used in conjunction with a detector (46) operable to generate a magnetic field of magnitude sufficient to cause re-magnetization responses of the temperature sensor elements (28-34,66,92) and optional data elements (38,40,20), to detect such responses, and to use the detected responses to determine the temperature of object (44) by means of a decoding algorithm. The temperature sensors (26,64,96) can be used in closed-loop heating systems (98) capable of controlling the heating of an object (114).
G01K 7/00 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
Small, low-cost wireless temperature sensors (120) are provided for sensing the temperature of servingware (121). Each temperature sensor preferably includes a substrate (124); at least one sensor element (122) positioned on the substrate; and an adhesive (126) for securing the sensor element to the substrate and for securing the temperature sensor to the servingware so that the sensor element may sense a temperature of the servingware. The temperature sensors may be used in conjunction with a reader/detector (136) operable to generate a magnetic field of magnitude sufficient to cause re-magnetization responses of the temperature sensor element and optional data elements to detect such responses, and to use the detected responses to determine the temperature of the servingware by means of a decoding algorithm. The temperature sensors can be used in closed-loop heating systems capable of controlling the heating of the servingware.
An improved antenna assembly (66) designed to maintain RF communication between an object (22, 64, 148) to be heated, and a heating assembly (20, 60) such as an induction heater having a hob (34) equipped with an induction work coil (36). The antenna assembly (66) provides substantially continuous RF communication about the entirety of the hob (34), so that the object (22, 64, 148) can be rotated through substantially 360° , or displaced radially, without loss of RF communication. The preferred antenna assembly (66) includes an antenna (67) mounted upon a substrate (68) and presenting a plurality of continuous, conductive antenna loops (70, 72) oriented to cooperatively and substantially surround the hob (34).
Improved treatment apparatus (120, 152) is provided for the treatment (e.g., molding, heating and/or curing) of objects such as parts or part precursors (148, 170) including wireless detection of a temperature parameter related to the objects during treatment thereof. The objects include associated microwire-type sensors (150, 174) which have characteristic re-magnetization responses under the influence of applied, alternating magnetic fields. The apparatus (120, 152) have treatment chambers (122, 153) sized to hold the objects to be treated, with one or more antennas (132, 124, 166) proximal to such objects and operable to generate interrogating alternating magnetic fields and to detect the responses of the sensors (150, 174). The detected temperature parameter information is used by an apparatus controller (146) to maintain desired ambient conditions within the treatment chamber (122, 153).
G01K 7/36 - Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat using magnetic elements, e.g. magnets, coils
A wiper assembly having a wiper with an inductively heatable portion, and an induction heating device including an induction work coil which is configured to be placed near the wiper to inductively heat the inductively heatable portion. The inductively heatable portion may be in the wiper blade, the wiper arm which supports the blade, or both. The induction work coil may be placed on or near the windshield or other surface which is cleaned by the wiper and may heat the wiper regardless of its position or only when the wiper is at a specific location such as its retracted “rest” position. The wiper assembly may also include a temperature sensor for sensing a current temperature of the wiper and control circuitry associated with the induction heating device for controlling operation of the work coil.)
Small, low-cost wireless temperature sensors (26,64,96) are provided for sensing the temperature of an object (44). The temperature sensors (26,64,96) preferably include a plurality of individual, magnetically susceptible temperature sensor elements (28-34,66,92), as well as optional magnetic field-responsive data elements (38,40,20) adapted for attachment to object (44) or to a substrate (82) in turn attached to object (44). The temperature sensor elements (28-34,66,92) preferably have magnetic bodies (22,70) exhibiting a re-magnetization response under the influence of an applied alternating magnetic field, which is different below and above a set point temperature, normally the Curie temperature of the magnetic body (22) or an adjacent sheath (74,94). The temperature sensors (26,64,96) are used in conjunction with a detector (46) operable to generate a magnetic field of magnitude sufficient to cause re-magnetization responses of the temperature sensor elements (28-34,66,92) and optional data elements (38,40,20), to detect such responses, and to use the detected responses to determine the temperature of object (44) by means of a decoding algorithm. The temperature sensors (26,64,96) can be used in closed-loop heating systems (98) capable of controlling the heating of an object (114).
patents
