Temperature estimation

Abstract

Regarding the estimation of the temperature of aerosol generation devices. [Solution] The method includes applying a pulse edge to a resonant circuit comprising an inductive element and a capacitor (for inductively heating a susceptor), wherein the applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency; determining the period or frequency of the resonant frequency of the pulse response; and converting the period or frequency determined based on a temperature gradient and calibration measurements into a temperature estimate.

Description

Technical Field

[0001] This specification relates to the estimation of temperature, for example, to the estimation of the temperature of an aerosol generating device.

Background Art

[0002] (Background) Smoking articles such as cigarettes and cigars generate tobacco smoke by burning tobacco during use. Attempts have been made to provide substitutes for these articles by creating products that release compounds without combustion. For example, a tobacco heating device forms an aerosol by heating an aerosol generating substrate such as tobacco and heating the substrate without burning it.

Summary of the Invention

[0003] (Summary) In a first aspect, this specification describes a method including steps of applying a pulse edge to a resonant circuit comprising an inductor and a capacitor for inductively heating a susceptor, the applied pulse edge causing a pulse response between the capacitor and the inductor of the resonant circuit, the pulse response having a resonant frequency; determining a period or frequency of the resonant frequency of the pulse response; and converting the determined period or frequency based on a temperature gradient (for example, a rate of change of the resonant frequency of the pulse response with respect to temperature) and a calibration measurement into a temperature estimate. The pulse edge may form part of an off-resonance pulse.

[0004] In some exemplary embodiments, the step of converting the determined period or frequency into the temperature estimate may include subtracting a calibration measurement from the determined period or frequency of the resonant frequency of the pulse response and dividing the result of the subtraction by the temperature gradient.

[0005] The calibration measurement may define a first period or frequency of the resonant frequency of the pulse response at a first temperature (for example, room temperature).

[0006] The calibration measurement may be obtained, for example, by subtracting the product of the gradient and the calibration temperature from the period of the pulse response at the calibration temperature.

[0007] This method may include the step of determining the calibration measurement value. Alternatively, this method may further include the step of determining the gradient.

[0008] In a second embodiment, this specification describes an apparatus comprising: a resonant circuit comprising an inductive element and a capacitor, wherein the inductive element is for inductive heating of a susceptor; a drive circuit (e.g., an H-bridge circuit or a half-bridge circuit) for applying a pulse edge to the resonant circuit, wherein the applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency; and a processor for determining the period or frequency of the resonant frequency of the pulse response and converting the determined period or frequency based on a temperature gradient and calibration measurements into a temperature estimate. The inductive element and the capacitor may be connected in series.

[0009] The processor may convert the determined period or frequency into the temperature estimate by subtracting a calibration measurement from the determined period or frequency of the resonant frequency of the pulse response, and then dividing the result of the subtraction by the temperature gradient.

[0010] The processor may be for determining the calibration measurement value. Alternatively, the processor may also be for determining the gradient.

[0011] In a third aspect, this specification describes a non-combustible aerosol generating device comprising the apparatus described above with reference to the second aspect. The aerosol generating device may be configured to receive a removable article containing an aerosol generating material. The aerosol generating material may include, for example, an aerosol generating substrate and an aerosol forming material. The removable article may include a susceptor structure.

[0012] In a fourth aspect, this specification describes a kit of components comprising articles for use in a non-combustible aerosol generating system, wherein the non-combustible aerosol generating system comprises the apparatus described above with reference to the second aspect or the aerosol generating device described above with reference to the third aspect. The articles may be removable articles comprising aerosol generating material.

[0013] In a fifth embodiment, this specification describes a computer program including instructions, wherein the instructions cause the device to apply a pulse edge to a resonant circuit comprising an inductive element and a capacitor for inductively heating a susceptor, wherein the applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency; determine the period or frequency of the resonant frequency of the pulse response; and convert the determined period or frequency, based on a temperature gradient and calibration measurements, into a temperature estimate. The computer program may be further configured to perform any embodiment of the method described above with reference to the first embodiment. [Brief explanation of the drawing]

[0014] Here, an exemplary embodiment will be described as merely an example with reference to the following schematic diagram. [Figure 1] This is a block diagram of a system according to an exemplary embodiment. [Figure 2] This figure shows a non-combustible aerosol supply device according to an exemplary embodiment. [Figure 3]It is a diagram of a non-combustible aerosol supply device according to an exemplary embodiment. [Figure 4] It is a diagram of an article for use with a non-combustible aerosol supply device according to an exemplary embodiment. [Figure 5] It is a block diagram of a circuit according to an exemplary embodiment. [Figure 6] It is a block diagram of a circuit according to an exemplary embodiment. [Figure 7] It is a block diagram of a system according to an exemplary embodiment. [Figure 8] It is a flowchart showing an algorithm according to an exemplary embodiment. [Figure 9] It is a plot showing a pulse according to an exemplary embodiment. [[ID=第十九]] [Figure 10] It is a plot showing a pulse response according to an exemplary embodiment. [Figure 11] It is a plot showing a pulse response according to an exemplary embodiment. [Figure 12] It is a plot showing the relationship between the pulse response period and temperature according to an exemplary embodiment. [Figure 13] It is a flowchart showing an algorithm according to an exemplary embodiment. [Figure 14] It is a block diagram of a circuit according to an exemplary embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0015] (Detailed Description) As used herein, the term "aerosol delivery device" is intended to encompass a system for delivering a substance to a user and includes the following: A non-combustible aerosol supply system that releases a compound from an aerosolizable material without burning the aerosolizable material, such as an electronic cigarette, a tobacco heating product, and a hybrid system that generates an aerosol using a combination of aerosolizable materials, and An article containing an aerosolizable material and configured to be used in one of these non-combustible aerosol supply systems.

[0016] According to the present disclosure, a "combustible" aerosol supply system is one in which the aerosolizable material that constitutes the aerosol supply system (or a component thereof) is burned or ignited to facilitate delivery to the user.

[0017] According to the present disclosure, a "non-combustible" aerosol supply system is one in which the aerosolizable material that constitutes the aerosol supply system (or a component thereof) is not burned or ignited to facilitate delivery to the user. In the embodiments described herein, the delivery system is a non-combustible aerosol supply system, for example, a powered non-combustible aerosol supply system.

[0018] In one embodiment, the non-combustible aerosol supply system is an electronic cigarette, which is also known as a vaping device or an electronic nicotine delivery system, but it should be noted that the presence of nicotine in the aerosolizable material is not a requirement.

[0019] In one embodiment, the non-combustible aerosol supply system is a tobacco heating system, which is also known as a non-combustion heating system.

[0020] In one embodiment, the non-combustible aerosol supply system is a hybrid system that uses a combination of aerosolizable materials to generate an aerosol, and one or more of the aerosolizable materials may be heated. Each of the aerosolizable materials may be in the form of, for example, a solid, liquid, or gel, and may or may not contain nicotine. In one embodiment, the hybrid system includes a liquid or gel aerosolizable material and a solid aerosolizable material. The solid aerosolizable material may include, for example, tobacco or non-tobacco products.

[0021] Typically, a non-combustible aerosol supply system may include a non-combustible aerosol supply device and articles for use with the non-combustible aerosol supply system. However, it is also conceivable that an article itself, which includes means for supplying power to an aerosol generating component, may form a non-combustible aerosol supply system.

[0022] In one embodiment, the non-combustible aerosol supply device may include a power source and a controller. The power source may be an electrical power source or a heat-generating power source. In one embodiment, the heat-generating power source includes a carbon substrate that can provide energy to supply power in the form of heat to an aerosolizable material or heat transfer material adjacent to the heat-generating power source. In one embodiment, the power source, such as the heat-generating power source, is provided within the article to form a non-combustible aerosol supply.

[0023] In one embodiment, an article for use with a non-combustible aerosol supply device may include an aerosolizable material, an aerosol generating component, an aerosol generating area, a mouthpiece, and / or an area for receiving the aerosolizable material.

[0024] In one embodiment, the aerosol generating component is a heater capable of interacting with an aerosolizable material to form an aerosol by releasing one or more volatile substances from the aerosolizable material. In one embodiment, the aerosol generating component is capable of generating an aerosol from an aerosolizable material without heating. For example, the aerosol generating component may be capable of generating an aerosol from an aerosolizable material without applying heat, for example, by one or more of vibration, mechanical, pressurizing, or electrostatic means.

[0025] In one embodiment, the aerosolizable material may comprise an active material, an aerosol-forming material, and optionally one or more functional materials. The active material may comprise nicotine (optionally contained in tobacco or tobacco derivatives) or one or more other non-olfactory physiologically active materials. Non-olfactory physiologically active materials are materials included in the aerosolizable material to realize physiological reactions other than olfaction. The active substance used herein may be a physiologically active material that is intended to realize or enhance a physiological reaction. The active substance may be selected from, for example, nutritional supplements, nootropics, and psychotropic drugs. The active substance may be natural or synthetically obtained. The active substance may comprise, for example, nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or components, derivatives, or combinations thereof. The active substance may comprise one or more components, derivatives, or extracts of tobacco, cannabis, or other plants. In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance includes caffeine, melatonin, or vitamin B12.

[0026] The aerosol-forming material may contain one or more of the following: glycerin, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso-erythritol, ethyl vanillate, ethyl laurate, diethyl suberate, triethyl citrate, triacetin, diacetin mixture, benzyl benzoate, benzyl phenylacetate, tributyline, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

[0027] One or more functional materials may include one or more of the following: fragrances, carriers, pH adjusters, stabilizers, and / or antioxidants.

[0028] In one embodiment, an article for use with a non-combustible aerosol supply device may include an aerosolizable material or a region for receiving the aerosolizable material. In one embodiment, an article for use with a non-combustible aerosol supply device may include a mouthpiece. The region for receiving the aerosolizable material may be a storage region for storing the aerosolizable material. For example, the storage region may be a reservoir. In one embodiment, the region for receiving the aerosolizable material may be separate from the aerosol generation region or may be combined with the aerosol generation region.

[0029] Aerosolizable materials, sometimes referred to herein as aerosol-generating materials, are materials capable of generating aerosols when, for example, heated, irradiated, or otherwise energized. Aerosolizable materials may be in the form of solids, liquids, or gels, which may or may not contain nicotine and / or flavorings. In some embodiments, aerosolizable materials may include amorphous solids, which may alternatively be referred to as monolithic solids (i.e., non-fibrous). In some embodiments, amorphous solids may be dry gels. Amorphous solids are solid materials capable of holding some fluid, such as a liquid, internally.

[0030] The aerosolizable material may be present on a substrate. The substrate may be, for example, paper, cardboard, cardboard, recycled aerosolizable material, plastic material, ceramic material, composite material, glass, metal, or metal alloy, or may contain these materials.

[0031] Consumables are articles containing or consisting of aerosol-generating materials, some or all of which are intended to be consumed by the user during use. Consumables may also include one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol-generating area, a housing, a wrapper, a mouthpiece, a filter, and / or an aerosol modifier. Consumables may also include an aerosol generator, such as a heater, which releases heat to generate an aerosol in the aerosol-generating material during use. The heater may include, for example, a flammable material, an electrically conductive material, or a susceptor.

[0032] Figure 1 is a block diagram of a system according to an exemplary embodiment, shown as a whole by reference numeral 10. The system 10 includes a power supply in the form of a direct current (DC) voltage source 11, a switching component 13, a resonant circuit 14, a susceptor component 16, and a control circuit 18. The switching component 13 and the resonant circuit 14 may be coupled to each other within an induction heating component 12 that can be used to heat the susceptor 16.

[0033] As will be discussed in detail below, the resonant circuit 14 may include a capacitor and one or more inductive elements for inductively heating the susceptor structure 16 to heat the aerosol-generating material. By heating the aerosol-generating material, an aerosol can be generated.

[0034] The switching component 13 may be capable of generating an alternating current from the DC voltage source 11 (under the control of the control circuit 18). The alternating current may flow through one or more inductive elements, which may cause heating of the susceptor component 16. The switching component may include multiple transistors. Examples of DC-AC converters include H-bridge circuits or inverter circuits, which will be discussed below.

[0035] A susceptor is a material that can be heated by the intrusion of a fluctuating magnetic field, such as an alternating magnetic field. The heating material may be a conductive material, in which case inductive heating of the heating material is induced when a fluctuating magnetic field intrudes into it. The heating material may also be a magnetic material, in which case magnetic hysteresis heating of the heating material is induced when a fluctuating magnetic field intrudes into it. The heating material may have both conductivity and magnetism, in which case the heating material can be heated by both heating mechanisms.

[0036] Induction heating is the process by which a conductive object is heated by allowing a fluctuating magnetic field to penetrate it. This process is described by Faraday's law of electromagnetic induction and Ohm's law. An induction heater may include an electromagnet and a device for passing a fluctuating current, such as an alternating current, through the electromagnet. When the electromagnet and the object to be heated are appropriately positioned relative to each other, and as a result the fluctuating magnetic field generated by the electromagnet penetrates the object, one or more eddy currents are generated within the object. Objects have resistance to the flow of electric current. Therefore, when such eddy currents are generated within an object, the object is heated because the eddy currents flow against the electrical resistance of the object. This process is called Joule heating, Ohm heating, or resistance heating. An object that can be induced heated is known as a susceptor.

[0037] In one embodiment, the susceptor is in the form of a closed circuit. In some embodiments, it has been found that when the susceptor is in the form of a closed circuit, the magnetic coupling between the susceptor and the electromagnet in use is strengthened, resulting in greater or improved Joule heating.

[0038] Magnetic hysteresis heating is a process in which an object made of a magnetic material is heated by the penetration of a fluctuating magnetic field into that object. A magnetic material can be thought of as being composed of numerous atomic-scale magnets or magnetic dipoles. When a magnetic field penetrates such a material, the orientation of the magnetic dipoles aligns with the magnetic field. Therefore, when a fluctuating magnetic field, such as an alternating magnetic field generated by an electromagnet, penetrates a magnetic material, the orientation of the magnetic dipoles changes due to the applied fluctuating magnetic field. This change in the orientation of the magnetic dipoles generates heat within the magnetic material.

[0039] When an object possesses both conductivity and magnetism, introducing a fluctuating magnetic field into the object can induce both Joule heating and magnetic hysteresis heating. Furthermore, using magnetic materials can enhance the magnetic field, thereby increasing Joule heating.

[0040] In each of the above processes, heat is generated within the object itself rather than through an external heat source via heat conduction. Therefore, by selecting appropriate object materials and shapes, as well as the appropriate magnitude and direction of the fluctuating magnetic field relative to the object, it is possible to achieve a rapid temperature rise and a more uniform heat distribution. Furthermore, in induction heating and magnetic hysteresis heating, there is no need to provide a physical connection between the source of the fluctuating magnetic field and the object, which may improve design flexibility and control of the heating profile, and may also reduce costs.

[0041] Figures 2 and 3 show a non-combustible aerosol supply device according to an exemplary embodiment, shown in its entirety by reference numeral 20. Figure 2 is a perspective view of the aerosol supply device 20A with an outer cover attached. The aerosol supply device 20A may include a replaceable article 21, which may be inserted into the aerosol supply device 20A to heat a susceptor (the susceptor may be included in the article 21, as will be discussed further below). The aerosol supply device 20A may further include an actuation switch 22 which may be used to turn the aerosol supply device 20A on or off.

[0042] Figure 3 shows the aerosol supply device 20B with its outer cover removed. The aerosol generating device 20B includes an article 21, an operating switch 22, a plurality of inductive elements 23a, 23b, and 23c, and one or more air tube extenders 24 and 25. The one or more air tube extenders 24 and 25 may be optional.

[0043] Multiple inductors 23a, 23b, and 23c may each form part of a resonant circuit, such as the resonant circuit 14. Inductor 23a may include a helical inductor coil. In one example, the helical inductor coil is made from Litz wire / cable wound in a spiral to provide a helical inductor coil. Many alternative inductor formations are possible, for example, the inductor is formed within a printed circuit board. Inductors 23b and 23c may be similar to inductor 23a. The use of the three inductors 23a, 23b, and 23c is not essential for all exemplary embodiments. Therefore, the aerosol generating device 20 may include one or more inductors.

[0044] The susceptor may be provided as part of article 21. In an exemplary embodiment, the insertion of article 21 into the aerosol generating device 20 may turn on the aerosol generating device 20 when article 21 is inserted into the aerosol generating device 20. This may be done, for example, by detecting the presence of article 21 in the aerosol generating device using a suitable sensor (e.g., a light sensor), or by detecting the presence of the susceptor using a resonant circuit 14 if the susceptor forms part of article 21. When the aerosol generating device 20 is turned on, the inductive element 23 may induce heating of article 21 through the susceptor. In an alternative embodiment, the susceptor may be provided as part of the aerosol generating device 20 (e.g., as part of a holder for receiving article 21).

[0045] Figure 4 shows an article for use with a non-combustible aerosol supply device according to an exemplary embodiment, shown in its entirety by reference numeral 30. Article 30 is an example of the interchangeable article 21 described above with reference to Figures 2 and 3.

[0046] Article 30 includes a mouthpiece 31 and a cylindrical rod of aerosol-generating material 33, which in this case is tobacco material, connected to the mouthpiece 31. The aerosol-generating material 33 provides an aerosol when heated in a non-combustible aerosol-generating device, such as the aerosol-generating device 20 described herein. The aerosol-generating material 33 is wrapped in a wrapper 32. The wrapper 32 may be, for example, a paper or paper-backed foil wrapper. The wrapper 32 may be substantially impermeable to air.

[0047] In one embodiment, the wrapper 32 includes aluminum foil. The aluminum foil has been found to be particularly effective in promoting aerosol formation within the aerosol-generating material 33. In one example, the aluminum foil has a metal layer having a thickness of about 6 μm. The aluminum foil may have a paper backing. However, in alternative configurations, the aluminum foil can have other thicknesses, for example, between 4 μm and 16 μm. The aluminum foil does not have to have a paper backing, but may have a backing formed from another material, for example, to help provide the foil with adequate tensile strength, or may not have a backing material at all. Metal layers or foils other than aluminum can also be used. Furthermore, it is not essential that such a metal layer be provided as part of article 30; for example, such a metal layer may be provided as part of apparatus 20.

[0048] The aerosol-generating material 33, also referred to herein as the aerosol-generating substrate 33, comprises at least one aerosol-forming material. In this example, the aerosol-forming material is glycerol. In alternative examples, the aerosol-forming material may be any other material or combination thereof as described herein. Aerosol-forming materials have been found to improve the perceived performance of an article by helping to transfer compounds, such as fragrance compounds, from the aerosol-generating material to the consumer.

[0049] As shown in Figure 4, the mouthpiece 31 of article 30 includes an upstream end 31a adjacent to the aerosol-generating substrate 33 and a downstream end 31b away from the aerosol-generating substrate 33. The aerosol-generating substrate may include tobacco, but alternatives are also possible.

[0050] In this example, the mouthpiece 31 includes a material body 36 upstream of the hollow tubular element 34, which is adjacent to and in contact with the hollow tubular element 34. The material body 36 and the hollow tubular element 34 each define a substantially cylindrical overall outer shape and share a common longitudinal axis. The material body 36 is wrapped in a first plug wrap 37. The first plug wrap 37 may have a basis weight of less than 50 gsm, such as between approximately 20 gsm and 40 gsm.

[0051] In this example, the hollow tubular element 34 is the first hollow tubular element 34, and the mouthpiece includes a second hollow tubular element 38, also called a cooling element, upstream of the first hollow tubular element 34. In this example, the second hollow tubular element 38 is upstream of the material body 36, adjacent to it, and in contact with it. The material body 36 and the second hollow tubular element 38 each define a substantially cylindrical overall outer shape and share a common longitudinal axis. The second hollow tubular element 38 is formed from multiple layers of paper, which are wound in parallel and joined at the seams to form the tubular element 38. In this example, the first and second layers of paper are provided in a double tube, but in other embodiments, three, four or more layers of paper can be used to form a triple, quadruple, or more layered tube. Other structures can also be used, such as spirally wound layers of paper, cardboard tubes, tubes formed using a papier-mâché type process, or molded or extruded plastic tubes. The second hollow tubular element 38 may also be formed using rigid plug wrap and / or tip paper as the second plug wrap 39 and / or tip paper 35 described herein, which means that a separate tubular element is not required.

[0052] The second hollow tubular element 38 is located around and defines a void within the mouthpiece 31 that functions as a cooling segment. The void provides a chamber through which heated volatile components generated by the aerosol-generating material 33 can flow. The second hollow tubular element 38 is hollow and provides a chamber for aerosol accumulation, but is rigid enough to withstand axial compressive forces and bending moments that may occur during manufacturing and use of the article 21. The second hollow tubular element 38 provides physical displacement between the aerosol-generating material 33 and the material body 36. The physical displacement provided by the second hollow tubular element 38 provides a temperature gradient along the length of the second hollow tubular element 38.

[0053] Naturally, article 30 is provided for illustrative purposes only. Those skilled in the art will notice many alternative configurations of such articles that can be used in the systems described herein.

[0054] Figure 5 is a block diagram of a circuit according to an exemplary embodiment, shown in its entirety by reference numeral 50. The circuit 50 includes a first switch 51, a second switch 52, a third switch 53, a fourth switch 54, and a resonant circuit 56. The first to fourth switches 51 to 54 may be implemented using transistors, as will be discussed further below.

[0055] The first to fourth switches 51 to 54 form an H-bridge circuit which may be used to apply pulses to the resonant circuit 56. Thus, the first to fourth switches 51 to 54 are implementation examples of the switching component 13, and the resonant circuit 56 is an example of the resonant circuit 14.

[0056] The first and second switches 51 and 52 form the first rim of the bridge circuit, and the third and fourth switches 53 and 54 form the second rim. More specifically, the first switch 51 controls the first power supply (V in Figure 5). DD A second switch 52 can selectively provide a connection between the first connection point and ground (labeled as such), a third switch 53 can selectively provide a connection between the first power supply and the second connection point, and a fourth switch 54 can selectively provide a connection between the second connection point and ground. A resonant circuit 56 is provided between the first and second connection points.

[0057] Figure 6 is a block diagram of a circuit according to an exemplary embodiment, shown in its entirety by reference numeral 60. Circuit 60 is an implementation example of circuit 50 described above.

[0058] Circuit 60 includes a positive terminal 67 and a negative (ground) terminal 68 (these are examples of implementations of the DC voltage source 11 of the system 10 described above). Circuit 60 includes a switching component 64 (which implements the switching component 13 described above), and the switching component 64 includes a bridge circuit (for example, an H-bridge circuit such as an FET H-bridge circuit). The switching component 64 includes a first rim 64a and a second rim 64b, which are coupled by a resonant circuit 69 (which implements the resonant circuits 14 and 56 described above). The first rim 64a includes switches 65a and 65b (which implement switches 51 and 52 described above), and the second rim 64b includes switches 65c and 65d (which implement switches 53 and 54 described above). Switches 65a, 65b, 65c, and 65d may be transistors such as field-effect transistors (FETs), and may receive input from a controller such as the control circuit 18 of system 10.

[0059] The resonant circuit 69 includes a capacitor 66 and an inductor 63 such that the resonant circuit 69 can be an LC resonant circuit. Circuit 60 further shows a susceptor equivalent circuit 62 (which implements the susceptor component 16). The susceptor equivalent circuit 62 includes a resistor and an inductor that demonstrate the electrical effects of an exemplary susceptor component 16. If a susceptor is present, the susceptor component 62 and the inductor 63 may function as a transformer 61. The transformer 61 may generate a fluctuating magnetic field such that the susceptor is heated when the circuit 60 receives power. During the heating operation in which the susceptor component 16 is heated by the inductor component, the switching component 64 is driven (for example by the control circuit 18) so that an alternating current flows through the resonant circuit 69, with the first and second branches coupled in sequence. The resonant circuit 69 has a resonant frequency partially based on the susceptor component 16, and the control circuit 18 may be configured to control the switching component 64 to switch at or near the resonant frequency. Driving the switching circuit at or near the resonant point helps improve efficiency and reduces energy lost to the switching element (which causes unnecessary heating of the switching element). In one example where an article 21 containing aluminum foil is heated, the switching component 64 may be driven at a frequency of around 2.5 MHz. However, in other implementations, the frequency may be anywhere between, for example, 500 kHz and 4 MHz.

[0060] Figure 7 is a block diagram of an exemplary embodiment of the system, shown in its entirety by reference numeral 70.

[0061] System 70 includes a pulse generation circuit 72, resonant circuits 74 (e.g., resonant circuits 56 and 69), a susceptor 76 (e.g., susceptor 16), and a pulse response processor 78. The pulse generation circuit 72 and the pulse response processor 74 may be implemented as part of the control circuit 18 of System 10.

[0062] The pulse generation circuit 72 may be implemented using the switching configurations of circuits 50 and 60 described above to generate pulses (e.g., pulse edges) by switching between positive and negative voltage sources. This is not required for all exemplary embodiments; for example, the pulse generation circuit 72 may be implemented using a half-bridge circuit, as will be discussed further below.

[0063] The pulse response processor 78 may determine one or more performance metrics (or features) of the resonant circuit 74 and the susceptor 76 based on the pulse response. For example, the pulse response processor 78 may generate an estimate of the temperature of the susceptor 76.

[0064] Figure 8 is a flowchart of an exemplary embodiment of the algorithm, shown in its entirety by reference numeral 80. Algorithm 80 illustrates an example of using System 70.

[0065] Algorithm 80 starts from operation 82, where a pulse edge is applied to the resonant circuit 74. The pulse edge is a rising or falling edge generated by the pulse generation circuit 72.

[0066] Figure 9 is a plot showing a pulse 90 according to an exemplary embodiment. The pulse 90 includes a rising pulse edge 92, which is an example of a pulse edge that may be applied in operation 82. The pulse 90 may be generated by a pulse generation circuit 72 (for example, by an H-bridge or half-bridge circuit).

[0067] The pulse 90 may be applied to the resonant circuit 74. Alternatively, in a system having multiple inductive elements (for example, the non-combustible aerosol construct 20 described above with reference to Figures 2 and 3), the pulse generation circuit 72 may select one of the multiple resonant circuits, each resonant circuit including an inductive element and a capacitor for inductive heating of a susceptor, and the applied pulse causes a pulse response between the capacitor and the inductive element of the selected resonant circuit.

[0068] When the pulse edge 92 is applied to the resonant circuit, a pulse response is generated.

[0069] Figure 10 is a plot, shown whole by reference no. 100, illustrating an exemplary pulse response that may be generated at the connection point between the capacitor 66 and inductor 63 of the resonant circuit 69 in response to a pulse edge 92. As shown in Figure 10, the pulse response 100 may take the form of a ringing resonance. The pulse response is the result of the bounce of charge between the inductor(s) and capacitor of the resonant circuit. In one configuration, this does not result in heating of the susceptor; that is, the temperature of the susceptor remains substantially constant (e.g., within ±1°C or ±0.1°C of the temperature before the pulse was applied). As shown in Figure 10, the pulse response 100 has a resonant frequency with a period 102 (this period is the time between consecutive peaks of the ringing response).

[0070] Figure 11 is a plot showing another exemplary pulse response that may be generated in response to a pulse edge 92, shown in its entirety by reference numeral 110. The pulse response 110 has a resonant frequency with a period 112.

[0071] In operation 84 of algorithm 80, the period or frequency of the resonant frequency of the pulse response generated in response to the applied pulse edge is determined (for example, by the pulse response processor 78). For the exemplary pulse response 100, the period or frequency determined in operation 84 is period 102. Similarly, for the exemplary pulse response 110, the period or frequency determined in operation 84 is period 112.

[0072] In operation 86 of algorithm 80, the period or frequency determined in operation 84 is converted into a temperature estimate, as will be discussed in detail below.

[0073] The voltages (V0) of pulse responses 100 and 110 may be expressed mathematically as follows: V0=sin(ω d t)·e-αt Here, ω d This is the damping resonance frequency of the system (including the susceptor). The relationship between alpha damping and damped frequency oscillation can also be given by the following equation:

[0074]

number

[0075]

number

[0076]

number

[0077] The period measured in the above operation 84 is the decay frequency (ω d ) based on.

[0078] Figure 12 is a plot showing the relationship between pulse response period and temperature, according to an exemplary embodiment, shown in its entirety by reference no. 120.

[0079] As the induction heating system, such as circuit 50 or 60 or system 70, heats up, the resistance within the system changes. As a result, the resonant frequency changes (and consequently, the period of the pulse response determined in operation 84 above also changes). As shown in exemplary plot 120, the pulse response period may lengthen as the temperature rises. In some exemplary embodiments, this change is linear (or nearly linear) and can therefore be used to estimate the temperature measurement.

[0080] If the characteristics of plot 120 are known, the period or frequency determined in operation 84 (e.g., the decay frequency of the system) can be converted into a temperature estimate in operation 86.

[0081] In operation 86, the temperature (x) may also be given by the following equation.

[0082]

number

[0083] The gradient m can be determined from two data points (x1, y1) and (x2, y2) as follows:

[0084]

number

[0085] For example, suppose a pulse response period of 400 ns is measured at a calibration temperature of 20 degrees Celsius. If the slope of plot 120 is determined to be 250 picoseconds per degree Celsius, then the above values ​​are given as follows: m = 250 ps / ℃ = 0.25 ns / ℃ c = -0.250 * 20 + 400 = 395 Therefore, if a period of 420 ns is determined in operation 84, this can be converted into a temperature estimate in operation 86 using the following equation.

[0086]

number

number

[0087] Figure 13 is a flowchart of an exemplary embodiment of the algorithm, shown in its entirety by reference no. 130.

[0088] In operation 132, the system gradient is determined. The gradient is the rate of change of the resonant frequency of the pulse response with respect to temperature. The gradient may be generated once (as part of the initialization process), then stored and may not be modified (or may be modified only rarely). Alternatively, the gradient measurement may be updated from time to time (for example, periodically, or in response to a determination that the gradient measurement may be unreliable).

[0089] In operation 134, the calibration measurement is determined. The calibration measurement may be determined by determining the period or frequency of the resonant frequency at a known temperature (e.g., the measured temperature). For example, the system may be calibrated based on a known room temperature (e.g., during the calibration process). Thus, the room temperature may be measured (e.g., using a thermocouple), and the pulse duration may be measured at this known room temperature.

[0090] Calibration measurements may be one-time measurements that are stored. Alternatively, calibration measurements may be repeatedly acquired from time to time, for example, when the system configuration may have changed. Many possible calibration configurations exist. For example, in a system with removable articles, including a heating susceptor component, the system may be recalibrated each time the removable article is replaced.

[0091] In operation 136, a temperature estimate is generated. Operation 136 may be performed using the algorithm 100 described above.

[0092] As mentioned above, the pulse edge may be generated using a full-bridge circuit in operation 82. This is not mandatory, and a half-bridge circuit may be used, for example.

[0093] Figure 14 is a block diagram of a circuit according to an exemplary embodiment, shown in its entirety by reference numeral 140. Circuit 140 includes the third switch 53, the fourth switch 54, and the resonant circuit 56 of the circuit 50 described above. The first connection point (between the first switch 51 and the resonant circuit 56) is connected to ground. For this reason, the second switch 52 of circuit 50 may be replaced with a permanent connection to ground, and the first switch 51 may be omitted.

[0094] Circuit 50 described above provides a full-bridge circuit for driving the resonant circuit 56. Circuit 140 provides a half-bridge circuit for driving the resonant circuit 56. For example, circuit 50 may be particularly suitable for providing pulses to drive the resonant circuit to inductively heat a susceptor, and circuit 140 may be particularly suitable for providing pulse edges to generate a pulsed response from the resonant circuit for analysis (e.g., measurement).

[0095] The various embodiments described herein are presented solely to aid in understanding and teaching the claimed features. These embodiments are provided only as representative examples of embodiments and are not exhaustive and / or exclusive. The advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein should not be considered as limitations to the scope of the invention as defined by the claims, or to equivalents thereof, and it should be understood that other embodiments may be used and modified without departing from the scope of the claimed invention. Various embodiments of the invention may suitably include, consist of, or essentially consist of, other disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. Furthermore, this disclosure may also include other inventions that are not currently claimed but may be claimed in the future.

Claims

1. A step of applying a pulse edge to a resonant circuit comprising an inductive element and a capacitor for inductive heating of a susceptor, wherein the applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency; A step of determining the period or frequency of the resonant frequency of the pulse response, A step of converting the period or frequency determined based on the temperature gradient and calibration measurement values ​​into a temperature estimate, Methods that include...

2. The step of converting the determined period or frequency into the temperature estimate is: Subtracting the calibration measurement value from the determined period or frequency of the resonant frequency of the pulse response, The result of the subtraction is divided by the temperature gradient, The method according to claim 1, including the method described in claim 1.

3. The method according to claim 1 or 2, wherein the calibration measurement value determines a first period or frequency of the resonant frequency of the pulse response at a first temperature.

4. The method according to claim 3, wherein the first temperature is room temperature.

5. The method according to any one of claims 1 to 4, wherein the calibration measurement value is obtained by subtracting the product of the gradient and the calibration temperature from the period of the pulse response at the calibration temperature.

6. The method according to any one of claims 1 to 5, wherein the gradient includes the rate of change of the resonant frequency of the pulse response with respect to temperature.

7. The method according to any one of claims 1 to 6, further comprising the step of determining the calibration measurement value.

8. The method according to any one of claims 1 to 7, further comprising the step of determining the gradient.

9. The method according to any one of claims 1 to 8, wherein the pulse edge forms part of the off-resonance pulse.

10. A resonant circuit comprising an inductive element and a capacitor, wherein the inductive element is for inductive heating of a susceptor, A drive circuit for applying a pulse edge to the resonant circuit, wherein the applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency. A processor for determining the period or frequency of the resonant frequency of the pulse response and converting the determined period or frequency into a temperature estimate based on the temperature gradient and calibration measurements, A device equipped with the following features.

11. The processor converts the determined period or frequency into the temperature estimate. Subtracting the calibration measurement value from the determined period or frequency of the resonant frequency of the pulse response, The result of the subtraction is divided by the temperature gradient, The apparatus according to claim 10, which is performed by [method].

12. The apparatus according to claim 10 or 11, wherein the processor is for determining the calibration measurement value.

13. The apparatus according to any one of claims 10 to 12, wherein the processor is for determining the gradient.

14. The apparatus according to any one of claims 10 to 13, wherein the inductive element and the capacitor are connected in series.

15. The apparatus according to any one of claims 10 to 14, wherein the drive circuit is an H-bridge circuit.

16. The apparatus according to any one of claims 10 to 14, wherein the drive circuit is a half-bridge circuit.

17. A non-combustible aerosol generating device comprising the apparatus described in any one of claims 10 to 16.

18. The non-combustible aerosol generating device according to claim 17, wherein the aerosol generating device is configured to receive a removable article containing an aerosol generating material.

19. The non-combustible aerosol generating device according to claim 18, wherein the aerosol generating material includes an aerosol generating substrate and an aerosol forming material.

20. The non-combustible aerosol generating device according to claim 18 or 19, wherein the removable article includes a susceptor structure.

21. A kit of components comprising articles for use in a non-combustible aerosol generation system, wherein the non-combustible aerosol generation system comprises the apparatus described in any one of claims 10 to 16 or the aerosol generation device described in any one of claims 17 to 20.

22. The parts kit according to claim 21, wherein the article is a removable article containing an aerosol-generating material.

23. A computer program including instructions, wherein the instructions are provided to a device at least Applying a pulse edge to a resonant circuit comprising an inductive element and a capacitor for inductive heating of a susceptor, wherein the applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency. Determining the period or frequency of the resonant frequency of the pulse response, Converting the determined period or frequency based on the temperature gradient and calibration measurements into a temperature estimate, A computer program that executes something.

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