Induced heating

Abstract

A device comprising a plurality of heater modules, each heater module comprising a resonant circuit having an inductive element for inductively heating a susceptor device and one or more capacitors. Each of the plurality of heater modules further comprises a bridge circuit for selectively coupling a first side and a second side of each of the plurality of heater modules to positive and negative supply voltages. The device further comprises a demultiplexer device for providing a clock signal to one of the plurality of heater modules in response to a control signal received from a control module, and a multiplexer device for providing a feedback signal from the one of the plurality of heater modules.

Description

Technical Field

[0001] This specification relates to the induction heating of susceptors.

Background Art

[0002] Many induction heating systems for heating susceptors are known. Further developments are still sought in this field.

Summary of the Invention

[0003] In a first aspect, this specification describes an apparatus. The apparatus comprises a plurality of heater modules, each heater module comprising a resonant circuit having an induction element for inductively heating a susceptor device and one or more capacitors. Each of the plurality of heater modules further comprises a bridge circuit for selectively coupling the first and second sides of the respective resonant circuit to positive and negative supply voltages. The apparatus comprises a demultiplexer device for providing a clock signal to a selected one of the plurality of heater modules in response to a control signal received from a control module, and a multiplexer device for providing a feedback signal from the selected one of the plurality of heater modules. The apparatus may further comprise the control module. The apparatus may be an aerosol generating device (or may form part of an aerosol generating device).

[0004] The demultiplexer device may comprise an input for receiving the clock signal, a control input for receiving the control signal, and a plurality of outputs for selectively providing the clock signal to the plurality of heater modules.

[0005] The multiplexer device may comprise a plurality of inputs coupled to the feedback outputs of each of the plurality of heater modules, a control input for receiving the control signal, and an output for providing a feedback signal from the selected one of the plurality of heater modules.

[0006] The multiplexer device may provide the feedback signal to the control module.

[0007] Some embodiments further include a clock signal generator for generating the clock signal.

[0008] The bridge circuit of each heater module may provide alternating current to its respective resonant circuit under the control of the control circuit. The bridge circuit of each heater module may comprise, for example, two half-bridge circuits.

[0009] The one or more capacitors in each heater module may include tuning capacitors. Each tuning capacitor may have a capacitance set at least partially depending on the position of each heater module within the device. Each tuning capacitor may have a capacitance set at least partially depending on one or more parameters that affect the resonant frequency of each heater module.

[0010] In other aspects, this specification describes an aerosol supply device comprising the apparatus described above with respect to the first aspect. The aerosol generating device may be configured to receive a detachable article containing an aerosol generating material. The aerosol generating material may include an aerosol generating substrate and an aerosol forming material. The detachable article may include a susceptor device. The device may also include a tobacco heating system.

[0011] In a further aspect, an aerosol supply system is provided. This system comprises an aerosol supply device having the apparatus described above in relation to a third aspect, and an article containing an aerosol generating material.

[0012] The aforementioned article may be equipped with a susceptor.

[0013] In a further aspect, a method for generating an aerosol is provided. This method comprises the steps of providing the aerosol supply system described above and inserting the aerosol product at least partially into a chamber.

[0014] In further aspects, this specification describes a method. This method comprises the steps of providing a clock signal to one selected of a plurality of heater modules in response to a control signal received from a control module, and providing a feedback signal from the selected of the plurality of heater modules. Here, each of the heater modules comprises a resonant circuit having an inductive element for inductively heating a susceptor device and one or more capacitors. Each of the plurality of heater modules further comprises a bridge circuit for selectively coupling a first and a second side of its respective resonant circuit to positive and negative supply voltages. The feedback signal may be provided to the control module. This method may further comprise the step of generating the clock signal.

[0015] This method may further comprise the step of setting the capacitance of one or more of the capacitors in a manner that depends at least partially on the location of each heater module and / or at least partially on one or more parameters that affect the resonant frequency of each heater module.

[0016] In further aspects, this specification describes a method. This method comprises the step of providing a control signal to a demultiplexer device, which is configured to provide a clock signal to one selected of a plurality of heater modules in response to the control signal. Each heater module comprises a resonant circuit, which has an inductive element for inductively heating a susceptor device and one or more capacitors. Each of the plurality of heater modules further comprises a bridge circuit for selectively coupling a first and a second side of its respective resonant circuit to positive and negative supply voltages. This method further comprises the step of receiving a feedback signal from the multiplexer device, which is provided by the selected one of the plurality of heater modules. This method may also comprise the step of providing the control signal to the multiplexer device.

[0017] This method may further comprise the step of setting the capacitance of one or more of the capacitors in a manner that depends at least partially on the location of each heater module and / or at least partially on one or more parameters that affect the resonant frequency of each heater module.

[0018] In further detail, this specification describes computer programs that include instructions causing an apparatus to perform (at least) one of the methods described herein (including the methods described above).

[0019] In further detail, this specification describes computer-readable media (e.g., non-temporary computer-readable media) on which program instructions for performing (at least) any of the methods described herein (including the methods described above) are stored.

[0020] In further detail, this specification describes computer-readable instructions. When these instructions are executed by a computing device, they cause that computing device to perform (at least) one of the methods described herein (including the methods described above).

[0021] In a further aspect, the present specification describes an apparatus comprising at least one processor and at least one memory. The memory includes computer program code which, when executed by the at least one processor, causes the apparatus to perform (at least) any of the methods described herein (including the methods described above).

Brief Description of the Drawings

[0022] By way of illustration only, exemplary embodiments will be described with reference to the following schematic diagrams.

[0023] [Figure 1] It is a block diagram of a system according to an embodiment. [Figure 2] It is a block diagram of a heating device according to an embodiment. [Figure 3] It is a diagram of a non-combustion aerosol supply system according to an embodiment. [Figure 4] It is a diagram of an article used in a non-combustion aerosol supply device according to an embodiment. [Figure 5] It is a block diagram of a circuit according to an embodiment. [Figure 6] It is a block diagram of a circuit according to an embodiment. [Figure 7] It is a flowchart showing an algorithm according to an embodiment. [Figure 8] It is a block diagram of a system according to an embodiment. [Figure 9] It is a plot diagram showing a pulse according to an embodiment. [Figure 10] It is a plot diagram showing a pulse response according to an embodiment. [Figure 11] It is a block diagram of a system according to an embodiment. [Figure 12] It is a flowchart showing an algorithm according to an embodiment. [Figure 13] It is a block diagram of a circuit according to an embodiment. [Figure 14]This is a block diagram of a circuit according to one embodiment. [Figure 15] This is a flowchart of the algorithm according to one embodiment. [Figure 16] This is a block diagram of a system according to one embodiment. [Figure 17] This is a flowchart of the algorithm according to one embodiment. [Figure 18] This is a block diagram of a circuit according to one embodiment. [Figure 19] This figure shows a circuit used in several embodiments. [Figure 20] This is a flowchart of the algorithm according to one embodiment. [Figure 21] This is a block diagram of a system according to one embodiment. [Modes for carrying out the invention]

[0024] As used in this book, the term "aerosol delivery device" is intended to encompass systems that deliver substances to users. A non-combustion aerosol supply system that releases compounds from an aerosolizable material without burning the material (for example, an e-cigarette, a heated tobacco product, and a hybrid system that generates aerosols using a combination of multiple aerosolizable materials), Includes an article comprising an aerosolizable material and configured for use in one of these non-combustible aerosol supply systems.

[0025] According to this disclosure, a “combustion-type” aerosol supply system is a system in which an aerosolizable material that is a component of the aerosol supply system (or a component thereof) is burned or incinerated in order to facilitate delivery to the user.

[0026] According to this disclosure, a “non-combustible” aerosol supply system is a system in which the aerosolizable material that constitutes the aerosol supply system (or its components) is not burned or incinerated in order 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.

[0027] In one embodiment, the non-combustible aerosol supply system is an electronic cigarette (also called a vaping device or electronic nicotine delivery system (END)), but it should be noted that the presence of nicotine in the aerosolizable material is not essential.

[0028] In one embodiment, the non-combustion aerosol supply system is a tobacco heating system (also called a non-combustion heating system).

[0029] In one embodiment, the non-combustible aerosol supply system is a hybrid system that generates an aerosol using a combination of multiple aerosolizable materials, one or more of which may be heated. Each of the aerosolizable materials may be, for example, in the form of a solid, liquid, or gel, and may or may not contain nicotine. In one embodiment, the hybrid system comprises a liquid or gel aerosolizable material and a solid aerosolizable material. The solid aerosolizable material may contain, for example, tobacco or a non-tobacco product.

[0030] Typically, a non-combustible aerosol supply system may comprise a non-combustible aerosol supply device and articles used in the non-combustible aerosol supply system. However, it is also conceivable that an article itself, which includes means for supplying power to the aerosol generating component, may constitute a non-combustible aerosol supply system.

[0031] 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 an exothermic power source. In one embodiment, the exothermic power source includes a carbon substrate capable of acting to distribute power in the form of heat to an aerosolizable material or heat transfer material located near the exothermic power source. In one embodiment, a power source such as an exothermic power source is provided within an article to constitute a non-combustible aerosol supply.

[0032] In one embodiment, the article used in a non-combustible aerosol supply device may comprise an aerosolizable material, an aerosol generating component, an aerosol generating region, a mouthpiece, and / or an aerosolizable material receiving region.

[0033] 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.

[0034] 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 found in tobacco or tobacco derivatives) or one or more other non-olfactory physiologically active materials. Non-olfactory physiologically active materials are substances included in the aerosolizable material to achieve physiological reactions other than olfaction. The active substances used herein may also be physiologically active materials. Physiologically active materials are substances intended to achieve or enhance physiological reactions. The active material may be selected from, for example, nutraceuticals, nootropics, or psychotropic drugs. The active material may be naturally derived or synthetically obtained. The active material may comprise, for example, nicotine, caffeine, taurine, theine, vitamins (e.g., vitamin B6 or B12 or C), melatonin, cannabinoids, or components, derivatives, or combinations thereof. The active material may comprise, for example, one or more components, derivatives, or extracts of tobacco, cannabis, or other plants. In some embodiments, the active substance includes nicotine. In some embodiments, the active material includes caffeine, melatonin, or vitamin B12. In one embodiment, the active substance is a legally permissible recreational drug.

[0035] 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 sverate, triethyl citrate, triacetin, diacetin mixture, benzyl benzoate, benzyl phenyl acetate, tributyline, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

[0036] One or more functional ingredients may include one or more of the following: fragrances, carriers, pH adjusters, stabilizers, and / or antioxidants.

[0037] In one embodiment, an article used in a non-combustible aerosol supply device may comprise an aerosolizable material or a region for receiving an aerosolizable material. In one embodiment, an article for use in a non-combustible aerosol supply device may comprise a mouthpiece. The region for receiving an 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 an aerosolizable material may be separated from or combined with an aerosol generating region.

[0038] Aerosolizable materials (also referred to as aerosol-generating materials in this document) are materials that can generate aerosols when energy is applied to them, for example, by heating, irradiation, or any other method. Aerosolizable materials may be in the form of solids, liquids, or gels, and may or may not contain nicotine and / or flavorings.

[0039] The aerosol-generating material may be an "amorphous solid." In some embodiments, the amorphous solid is a "monolithic solid." The aerosol-generating material may be non-fibrous or fibrous. In some embodiments, the aerosol-generating material may be a dry gel. The aerosol-generating material may be a solid material capable of holding a fluid, such as a liquid, internally. In some embodiments, the held fluid may be water (e.g., water absorbed from the surroundings of the aerosol-generating material), or the held fluid may be a solvent (e.g., a solvent when the aerosol-generating material is formed from a slurry). In some embodiments, the solvent may be water.

[0040] The aerosolizable material may be present on a substrate. The substrate may be, for example, paper, cardboard, cardboard, reconstituted aerosolizable material, plastic material, ceramic material, composite material, glass, metal, or metal alloy.

[0041] Consumables are articles comprising or consisting of aerosol-generating material, which are intended to be consumed by the user, in whole or in part, during use. Consumables may comprise 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 comprise an aerosol generator, such as a heater, which generates heat to cause the aerosol-generating material to produce an aerosol during use. The heater may comprise, for example, a flammable material or a material that can be heated by electrical conductivity.

[0042] Figure 1 is a block diagram of a system according to one embodiment (indicated by reference numeral 10). The system 10 comprises a power source in the form of a direct current (DC) voltage source 11, a switching device 13, a resonant circuit 14, a susceptor device 16, and a control circuit 18. The switching device 13 and the resonant circuit 14 can be coupled to form an induction heating device 12 that can be used to heat the susceptor 16.

[0043] As will be described later, the resonant circuit 14 may include one or more capacitors and one or more inductive elements for inductively heating the susceptor device 16 to heat the aerosol-generating material. Aerosols may be generated by heating the aerosol-generating material.

[0044] The switching device 13 may enable the generation of an alternating current from the DC voltage source 11 (under the control of the control circuit 18). This alternating current may flow through one or more inductive elements and may cause heating of the susceptor device 16. The switching device may include multiple transistors. The exemplary DC-AC converters include an H-bridge or inverter circuit. These examples will be described later.

[0045] The susceptor is a material that can be heated by the intrusion of a fluctuating magnetic field (e.g., an alternating magnetic field). This heating material may be a conductive material or a thermally conductive material so that induction heating occurs when a fluctuating magnetic field is intruded into the heating material. The heating material may be a magnetic material so that magnetic hysteresis heating occurs when a fluctuating magnetic field is intruded into the heating material. The heating material may have both conductivity and magnetism so that it can be heated by both heating mechanisms.

[0046] 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 induction and Ohm's law. An induction heater may consist of an electromagnet and a device for passing a fluctuating current, such as alternating current, through the electromagnet. When the electromagnet and the object to be heated are positioned in the appropriate relative positions so that the fluctuating magnetic field created by the electromagnet penetrates the object, one or more eddy currents are generated within the object. The object has resistance to this current flow. Therefore, once these eddy currents are generated within the object, the object is heated as the eddy currents flow against the object's electrical resistance. This process is called Joule heating, Ohmian heating, or resistance heating. An object that can be induction heated is known as a susceptor.

[0047] 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 the object. A magnetic material can be thought of as containing numerous atomic-scale magnets, or magnetic dipoles. When a magnetic field penetrates such a material, the magnetic dipoles align with the field. Therefore, when a fluctuating magnetic field, such as an alternating magnetic field created by an electromagnet, penetrates a magnetic material, the orientation of the magnetic dipoles changes in accordance with the fluctuating applied magnetic field. This reorientation of magnetic dipoles generates heat within the magnetic material.

[0048] When an object possesses both conductivity and magnetism, both Joule heating and magnetic hysteresis heating can be induced within the object by introducing a fluctuating magnetic field. Furthermore, the magnetic field can be strengthened by using magnetic materials, thereby enhancing Joule heating.

[0049] In each of the processes described above, heat is generated within the object itself, rather than being heated by heat conduction from an external heat source. Therefore, by selecting the appropriate material and shape of the object, as well as the appropriate magnitude and orientation of the fluctuating magnetic field relative to the object, it is possible to achieve a rapid temperature rise within the object and a more uniform heat distribution. Furthermore, since induction heating and magnetic hysteresis heating do not require a physical connection between the fluctuating magnetic field source and the object, it is possible to greatly increase the design flexibility and controllability of the heating profile, and reduce costs.

[0050] Figure 2 is a block diagram of a heating device (indicated by reference numeral 12a) according to one embodiment. The heating device 12a is similar to the heating device 12 described above. In the heating device 12a, instead of the single resonant circuit 14 of the heating device 12, multiple resonant circuits (shown as a first resonant circuit 14a, a second resonant circuit 14b, and an nth resonant circuit 14n) are provided. The switching module 13 of the heating device 11 is replaced by a switching device 13a that can independently control the multiple resonant circuits 14a to 14n.

[0051] Each of the resonant circuits 14a to 14n may include a capacitor and one or more inductive elements for inductively heating a susceptor device (e.g., susceptor device 16). This heating may be used, for example, to heat an aerosol-generating material to produce an aerosol. In one example of the use of the heating device 12a, the resonant circuits 14a to 14n can be used to heat different parts of the susceptor (e.g., susceptor 16).

[0052] Figure 3 shows a non-combustible aerosol supply system according to one embodiment (indicated overall by reference numeral 20). The aerosol supply system 20 comprises an aerosol supply device 20A, shown with the external cover removed. The aerosol supply device 20A is an example of an induction heating device that can be controlled according to the principles described herein.

[0053] The aerosol supply system 20 includes a replaceable article 21 that can be inserted into the aerosol supply device 20A to enable heating of the susceptor (the susceptor may be contained within the article 21, as described later). The aerosol supply device 20A may further include an actuation switch 22 that can be used to switch the aerosol supply device 20A on or off.

[0054] The aerosol generating device 20A comprises a plurality of induction elements 23a, 23b, and 23c, and one or more air tube extenders 24 and 25. These one or more air tube extenders 24 and 25 may be optional. The operating switch 22 may also be optional, and may be provided with, for example, a pressure trigger or other on-demand operating device.

[0055] Multiple inductive elements 23a, 23b, and 23c may each constitute part of a resonant circuit (for example, the resonant circuits 14a, 14b, and 14n described above). Inductive element 23a may include a helical inductor coil. In one example, the helical inductor coil is made from Litz wire / cable, which is wound spirally to produce the helical inductor coil. Many other inductor configurations are also possible, such as inductors formed within a printed circuit board. Inductive elements 23b and 23c may be similar to inductive element 23a. Of course, the use of three inductive elements 23a, 23b, and 23c is just one example, and the aerosol generating device 20 may have more or fewer inductive elements than three.

[0056] The susceptor may be provided as part of the article 21. In one embodiment, the aerosol generating device 20A may be activated by the insertion of the article 21 when the article 21 is inserted into the aerosol generating device 20A. This may be done by detecting the presence of the article 21 in the aerosol generating device using a suitable sensor (e.g., an optical sensor), or, if the susceptor is part of the article 21, by detecting the presence of the susceptor using, for example, a resonant circuit 14. When the aerosol generating device 20A is activated, the inductive elements 23a to 23c may cause inductive heating of the article 21 via the susceptor. In other embodiments, the susceptor may be provided as part of the aerosol generating device 20A (e.g., as part of a holder that receives the article 21).

[0057] Figure 4 shows an article (indicated overall by reference numeral 30) used in a non-combustible aerosol supply device according to one embodiment. Article 30 is an example of the replaceable article 21 described above with reference to Figure 3.

[0058] Article 30 comprises a mouthpiece 31 and a cylindrical rod made of an aerosol-generating material 33 (in this example, tobacco material) connected to the mouthpiece 31. The aerosol-generating material 33 produces an aerosol when heated, for example, when heated in a non-combustible aerosol-generating device (such as the aerosol-generating device 20 described above). The aerosol-generating material 33 is wrapped in a wrapper 32. The wrapper 32 may be, for example, a paper wrapper or a foil wrapper backed with paper. The wrapper 32 may be substantially air-impermeable.

[0059] In one embodiment, the wrapper 32 comprises aluminum foil. Aluminum foil has been found to particularly effectively promote aerosol formation within the aerosol-generating material 33. In one example, the aluminum foil has a metal layer approximately 6 μm thick. This aluminum foil may have a paper backing. However, in other configurations, the aluminum foil can have other thicknesses, for example, 4 μm to 16 μm. The aluminum foil does not need to have a paper backing, but may have a backing made of another material, for example, to help provide the foil with appropriate tensile strength, or it 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 the article 30; for example, such a metal layer can be provided as part of the apparatus 20.

[0060] The aerosol-generating material 33 (also referred to as the aerosol-generating substrate 33 in this document) comprises at least one aerosol-forming material. In this example, the aerosol-forming material is glycerol. In other examples, the aerosol-forming material may be other materials described in this document or combinations thereof. Aerosol-forming materials are known to improve the sensory performance of an article by assisting in the transfer of compounds (e.g., flavor components) from the aerosol-generating material to the consumer.

[0061] As shown in Figure 4, the mouthpiece 31 of article 30 has 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 contain tobacco, but other configurations are also possible.

[0062] In this example, the mouthpiece 31 includes a material body 36 upstream of the hollow tubular element 34, where the material body 36 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 shape and share a common longitudinal axis. The material body 36 is encased in a first plug wrap 37. The first plug wrap 37 may have a basis weight less than 50 gsm, for example, about 20 gsm to 40 gsm.

[0063] In this example, the hollow tubular element 34 is a 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 the material body 36, and in contact with the material body 36. The material body 36 and the second hollow tubular element 38 each define a substantially cylindrical overall shape and have a common longitudinal axis. The second hollow tubular element 38 is formed from multiple paper layers, which are wound in parallel with their seams facing each other to form the tubular element 38. In this example, the first and second paper layers are provided to form a two-layer tube, but in other examples, three, four or more paper layers may be used to form a three-, four or more-layer tube. Other possible configurations include spiral-wrapped paper layers, cardboard tubes, tubes formed using a paper mache process, and molded or extruded plastic tubes. The second hollow tubular element 38 may also be formed using rigid plug wrap and / or chipping paper as the second plug wrap 39 and / or chipping paper 35 described herein, which means that a separate tubular element is not required.

[0064] The second hollow tubular element 38 is positioned within the mouthpiece 31 and defines a void that functions as a cooling segment. This void provides a chamber through which heated volatile components generated by the aerosol-generating material 33 can pass. The second hollow tubular element 38 is hollow to provide 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 a physical displacement between the aerosol-generating material 33 and the material body 36. The physical displacement provided by the second hollow tubular element 38 results in a thermal gradient along the length of the second hollow tubular element 38.

[0065] Of course, article 30 is merely an example. Those skilled in the art will recognize many alternative configurations of such articles that can be used in the systems described herein. Similarly, those skilled in the art will recognize other articles that can be heated using the principles described herein.

[0066] Figure 5 is a block diagram of a circuit according to one embodiment (indicated by reference numeral 50). The circuit 50 comprises 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 described later.

[0067] The first to fourth H-bridge circuit switches 51 to 54 form an H-bridge circuit used to apply pulses to the resonant circuit 56, with the first and second switches 51 and 52 forming the first half-bridge, and the third and fourth switches 53 and 54 forming the second half-bridge. Therefore, the first to fourth switches 51 to 54 are one implementation example of the switching devices 13 and 13a, and the resonant circuit 56 is an example of the resonant circuits 14, 14a, 14b, and 14n described above.

[0068] The first and second switches 51 and 52 form the first limb of the full H-bridge circuit, and the third and fourth switches 53 and 54 form the second limb. More specifically, the first switch 51 is connected to the first power supply (V in Figure 5).DD The first connection point is selectively provided by the second switch 52, the first connection point is selectively provided by the third switch 53, the first connection point is selectively provided by the fourth switch 54, and the second connection point is selectively provided by the fourth switch 54. The resonant circuit 56 is provided between the first and second connection points.

[0069] Figure 6 is a block diagram of a circuit according to one embodiment (indicated overall by reference numeral 60). Circuit 60 is an example of implementation of the circuit 50 described above.

[0070] Circuit 60 includes a positive terminal 67 and a negative (ground) terminal 68 (these are one implementation example of the DC voltage source 11 of the system 10 described above). Circuit 60 includes a switching device 64 (implementing the switching devices 13 and 13a described above), where the switching device 64 includes a bridge circuit (for example, an H-bridge circuit such as a FETH bridge circuit). The switching device 64 includes a first limb 64a and a second limb 64b, where the first limb 64a and the second limb 64b are coupled by a resonant circuit 69 (this resonant circuit implements the resonant circuits 14, 14a, 14b, 14n and 56 described above). The first limb 64a includes switches 65a and 65b (implementing the switches 51 and 52 described above), and the second limb 64b includes switches 65c and 65d (implementing the switches 53 and 54 described above). Switches 65a, 65b, 65c, and 65d may be transistors (e.g., field-effect transistors (FETs)) and may receive input from a controller (e.g., the control circuit 18 of system 10).

[0071] The resonant circuit 69 comprises a capacitor 66 and an inductive element 63 so that the resonant circuit 69 can be an LC resonant circuit. Circuit 60 further shows a susceptor equivalent circuit 62 (representing, for example, the susceptor device 16 of the system 10 described above). The susceptor equivalent circuit 62 comprises a resistor and an inductive element, which represent the electrical effects of an example of a susceptor device (e.g., susceptor 16). If a susceptor is present, the susceptor device 62 and the inductive element 63 can function as a transformer 61. The transformer 61 can generate a fluctuating magnetic field so that the susceptor is heated when circuit 60 receives power. During the heating operation mode in which the susceptor device 16 is heated by the inductive device, the switching device 64 is driven (e.g., by the control circuit 18) so that each of the first and second branches is alternately coupled so that an alternating current flows through the resonant circuit 69. The resonant circuit 69 will have a resonant frequency, which is partially based on the susceptor device 16. The control circuit 18 may be configured to control the switching device 64 to switch at the resonant frequency or a frequency near the resonant frequency. Driving the switching circuit at or near the resonant frequency improves efficiency and reduces energy loss to the switching elements (which causes unwanted heating of the switching elements). In an example where an article comprising aluminum foil is heated, the switching device 64 may be driven at a frequency of approximately 2.5 MHz. However, in other implementations, the frequency may be any value between, for example, 500 kHz and 4 MHz.

[0072] Figure 7 is a flowchart of an algorithm according to one embodiment (indicated overall by reference numeral 70). Algorithm 70 may be implemented using the system 10 described above.

[0073] Algorithm 70 begins in process 72, where a resonant circuit (e.g., resonant circuit 14, or one of resonant circuits 14a, 14b, and 14n) is driven at its resonant frequency in the heating operation mode. For example, a switching device 13 or 13a may be switched at the measured resonant frequencies of each resonant circuit 14, 14a, 14b, and 14n (e.g., under the control of control circuit 18). The effectiveness of heating mode 72 may depend on the accuracy of the measurement of the resonant frequency. The effectiveness of heating mode 72 may depend on the resolution of the output frequency used to drive the resonant circuit.

[0074] Process 74 enters sampling operation mode. The sampling mode may attempt to measure the resonant frequency used in the heating mode (for example, during the next iteration of algorithm 70). As will be described in more detail later, the sampling mode may include applying pulses to the resonant circuit at specified time intervals and processing the resonant response to measure / estimate the resonant frequency.

[0075] In process 76, the drive frequency of the resonant circuit is set based on the measured resonant frequency.

[0076] Thus, the heating mode parameters (including the drive frequency and sampling interval) are set in process 76. Heating of the susceptor is performed in the next iteration of heating mode 72 until the time interval indicated by the sampling mode occurs. The algorithm 70 then enters sampling mode 74 again, the resonant frequency of the resonant circuit is measured again, and the heating and sampling mode parameters are updated (in process 76).

[0077] Figure 8 is a block diagram of a system according to one embodiment (indicated overall by reference numeral 80).

[0078] System 80 comprises a pulse generation circuit 82, resonant circuits 84 (e.g., resonant circuits 14, 14a, 14b, 14n, 56, and 69), a susceptor 86 (e.g., susceptor 16), and a pulse response processor 88. The pulse generation circuit 82 and the pulse response processor 84 may be implemented as part of the control circuit 18 of system 10, or they may be used in the sampling mode 76 of algorithm 70.

[0079] The pulse generation circuit 82 may be implemented using the switching devices 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 in all embodiments; for example, the pulse generation circuit 82 may be implemented using a half-bridge circuit.

[0080] The pulse response processor 88 may determine one or more performance indicators (or characteristics) of the resonant circuit 84 and the susceptor 86 based on the pulse response. For example, the pulse response processor 88 may generate estimates of the temperature of the susceptor 86 and / or the resonant frequency of the resonant circuit.

[0081] Figure 9 is a plot showing a pulse 90 according to one embodiment. The pulse 90 includes a rising pulse edge 92, which is an example of a pulse edge that can be applied to the resonant circuit 84. The pulse 90 may be generated by the pulse generation circuit 82 (for example, by an H-bridge or half-bridge circuit). The pulse 90 may be applied, for example, during the sampling mode 74 of algorithm 70 (for example, to generate a pulse response used for estimating temperature and / or resonant frequency).

[0082] The pulse 90 may be applied to the resonant circuit 84. In another example, in a system having multiple inductive elements, the pulse generation circuit 82 may select one of multiple resonant circuits (each resonant circuit comprising an inductive element for inductive heating of a susceptor and a capacitor), and the applied pulse may induce a pulse response between the capacitor and the inductive element of the selected resonant circuit.

[0083] By applying the pulse edge 92 to the resonant circuit 84, a pulse response is generated.

[0084] Figure 10 is a plot (indicated overall by reference numeral 100) showing an exemplary pulse response that can be generated in response to a pulse edge 92 at the connection point between the capacitor 66 and the inductor 63 of the resonant circuit 69 described above. As shown in Figure 10, the pulse response 100 can take the form of a ringing resonance. The pulse response is the result of charge bounce between the inductor and capacitor of the resonant circuit. In some configurations, this does not result in heating of the susceptor; that is, the temperature of the susceptor is kept substantially constant (e.g., within ±1°C or ±0.1°C from the temperature before pulse application). As shown in Figure 10, the resonant frequency of the pulse response can be measured using the period 102 between zero crossings. In some embodiments, other measured values, such as the period between consecutive peaks of the ringing response, may be used.

[0085] Figure 11 is a block diagram of a system according to one embodiment (indicated by reference numeral 110). System 110 may constitute part of an aerosol generating device (for example, the aerosol supply device 20 described above).

[0086] System 110 comprises a demultiplexer unit 112, a plurality of heater modules 114a, 114b, 114n, a multiplexer unit 116, a control module 117, and a clock generator 118. Each heater module includes a resonant circuit, which will be described in detail later. Although three heater modules are shown in Figure 11, some system examples may include more or fewer heater modules.

[0087] The demultiplexer device 112 has an input for receiving a clock signal from the clock generator 118, a control input for receiving a control signal from the control module 117, and a plurality of outputs. These plurality of outputs selectively provide the clock signal (or a signal derived from the clock signal) to the plurality of heater modules 114a to 114n. In this way, the demultiplexer device 112 provides the clock signal to one of the heater modules 114a, 114b, and 114n selected according to the control signal.

[0088] Each of the heater modules 114a, 114b, and 114n has a resonant circuit (further discussed below) comprising an inductive element and one or more capacitors for inductively heating the susceptor device, similar to the resonant circuits 14a, 14b, and 14n described above. Each of these heater modules provides a feedback signal (e.g., current measurement) to the multiplexer device 116.

[0089] The multiplexer device 116 receives a control input from the control module 117. A feedback signal from the selected heater module is provided to the control module 117 based on this control input. The control signal received by the multiplexer 116 may be the same as the control signal provided to the demultiplexer device 112. In this way, the feedback signal output by the multiplexer device 116 is associated with the heater module driven by the clock signal output by the demultiplexer device 112.

[0090] Figure 12 is a flowchart of an algorithm according to one embodiment (indicated overall by reference numeral 120). Algorithm 120 may be implemented using the system 110 described above.

[0091] Algorithm 120 begins in process 122, where signals for driving the heater modules are generated. For example, a clock signal may be provided to one of several selected heater modules (e.g., one of modules 114a, 114b, and 114n) in response to a control signal received from the control module. For example, the clock signal may be provided to one of the aforementioned heater modules 114a, 114b, and 114n based on a control signal received from the control module 117.

[0092] In process 124, a feedback signal is obtained from the heater module selected in process 122. For example, the selected feedback signal may be provided to the control module 117. As described above, the feedback signal may be output by the multiplexer device 116 in response to the control signal received from the control module 117.

[0093] In process 126, the control of the heating system is updated based on the feedback signal. For example, the feedback signal may provide temperature information related to the heating operation, and the control of the heating operation may be updated based on the feedback signal. Those skilled in the art will also recognize other feedback signals that can be used to control the system.

[0094] Figure 13 is a block diagram of a circuit according to one embodiment (indicated overall by reference numeral 130). Circuit 130 may be used to implement heater modules 114a, 114b, and 114n, respectively.

[0095] The circuit 130 comprises a first half-bridge circuit 132, a second half-bridge circuit 133, and an RLC resonant circuit 134 (which includes an inductive element for inductively heating the susceptor device and one or more capacitors).

[0096] Half-bridge circuits 132 and 133 receive control signals from the demultiplexer device 112 and are used to selectively couple the first and second sides of the resonant circuit 134 to positive and negative supply voltages. These half-bridge circuits, as a whole, provide alternating current to the resonant circuit under the control input received from the demultiplexer device 112. In this way, the selected heater module can be driven.

[0097] Figure 14 is a block diagram of a circuit according to one embodiment (indicated overall by reference numeral 140). Circuit 140 is an implementation example of circuit 130 described above and is similar to circuit 50 described above.

[0098] Circuit 50 comprises a first switch 141, a second switch 142, a third switch 143, a fourth switch 144, and a resonant circuit 146 (e.g., an RLC resonant circuit). The first to fourth switches 141 to 144 may be implemented using transistors, as will be further described below.

[0099] The first and second switches 141 and 142 form a half-bridge circuit (e.g., the first half-bridge circuit 132), and the third and fourth switches 143 and 144 form a second half-bridge circuit (e.g., the second half-bridge circuit 133). These switches receive clock signals (CLKn and its invertor / CLKn) that can be used to apply pulses to the resonant circuit 146.

[0100] These clock signals may be received from the demultiplexer device 112. If the resonant circuit 140 is not selected for heating, the clock signals can be disabled (for example, by closing the second switch 142 and the fourth switch 144, and connecting both sides of the resonant circuit 146 to ground with the first and third switches 141 and 143 open). If the resonant circuit is selected for heating, the demultiplexer device 112 provides switching signals to the first to fourth switches so that the resonant circuit 146 is driven, ideally, at (or near) the resonant frequency of the resonant circuit.

[0101] Each of the multiple heater modules (e.g., heater modules 114a, 114b, and 114n) is physically positioned at different locations within the circuit and at different distances from other circuit elements (e.g., demultiplexer 112). This can affect the capacitance within the circuit and therefore the resonant frequency of the resonant heater circuit. Some embodiments attempt to compensate for this variation in resonant frequency. For example, one or more capacitors in each heater module may include tuning capacitors.

[0102] Figure 15 is a flowchart of an algorithm according to one embodiment (indicated overall by reference numeral 150).

[0103] Algorithm 150 begins in process 152, where parameters that may affect the resonant frequency of each heater module (e.g., one of heater modules 114a, 114b, and 114n) are determined. These parameters may include the location of the heater module in the circuit (which particularly affects the resistance of RLC heater modules, but may also affect the inductance and / or capacitance). Based on this location, the relevant distances are determined. In addition to or in addition to these, these parameters may include the manufacturing tolerances of the resistors, inductors, and / or capacitors of the heater module.

[0104] In process 154, the capacitance of the tuning capacitor of the heater module is set, at least partially depending on the parameters determined in process 152.

[0105] Figure 16 is a block diagram of a system according to one embodiment. System 160 may constitute a part of an aerosol generation device (for example, the aerosol supply device 20 described above).

[0106] System 160 comprises a clock signal generator 161, a first switching circuit 162, a second switching circuit 163, a plurality of heater modules 164a, 164b, 164n, and a control circuit 166. The clock signal generator 161 provides clock signals to the first and second switching circuits 162 and 163. Each heater module has a resonant circuit comprising an inductive element and one or more capacitors for inductively heating the susceptor device. Although three heater modules are shown in Figure 16, some examples of systems may include more or fewer heater modules.

[0107] The first switching circuit 162 has an output for providing a first positive or negative supply voltage to the heater module. Similarly, the second switching circuit 163 has an output for providing a second positive or negative supply voltage to the heater module.

[0108] As will be further described below, each of the multiple heater modules 164a to 164n has a first switch for selectively coupling the first side of the resonant circuit to the output of the first switching circuit 162, and a second switch for selectively coupling the second side of the resonant circuit to the output of the second switching circuit 163. The control module 166 functions as a heater selection module, selecting one of the multiple heater modules 164a, 164b, and 164n as the selected heater module and controlling the first and second switches. All heater modules other than the active module may be non-selected heater modules. Similarly, a single feedback signal may be provided to the control module 166 by the selected heater module. This feedback signal may, for example, indicate the current flowing through the selected resonant circuit.

[0109] The first and second switching circuits 162 and 163 can be used to provide alternating current to the select heater module (selected by the control module 166). The first and second switching circuits may also be half-bridge circuits (for example, the half-bridge circuits described above with reference to Figure 14).

[0110] It should be noted that providing switches within heater modules 164a to 164n means that the multiplexer configuration of system 110 described above becomes unnecessary.

[0111] As described above with reference to Algorithm 150, each of the multiple heater modules (e.g., heater modules 164a, 164b, and 164n) is physically positioned at different locations within the circuit and at different distances from other circuit elements (e.g., switching circuits 162 and 163 and control circuit 166). This can affect the capacitance in the circuit and therefore the resonant frequency of the resonant heater circuit. Some embodiments attempt to compensate for this variation in resonant frequency. For example, one or more capacitors in each heater module may include a tuning capacitor. As stated with reference to Algorithm 150, the capacitance of the tuning capacitor of a heater module may be set at least partially depending on the location of that heater module. In addition to (or instead of) this, the capacitance of the tuning capacitor of a heater module may be set depending on other parameters that can affect the resonant frequency of that heater module (e.g., manufacturing tolerances of the resistors, inductors, and / or capacitors of that heater module).

[0112] Figure 17 is a flowchart of an algorithm according to one embodiment (indicated overall by reference numeral 170). Algorithm 170 may be implemented using the system 160 described above.

[0113] Algorithm 170 begins in process 172, where the first switching circuit 162 and the second switching circuit 163 are driven to provide a first positive or negative supply voltage and a second positive or negative supply voltage, respectively (therefore providing alternating current).

[0114] In process 174 of algorithm 174, the first and second switches of each of the multiple heater modules are controlled so that the selected heater module is coupled to the first positive or negative supply voltage, and the selected heater module is coupled to the second positive or negative supply voltage. The switches of the unselected heater modules can be opened so that those heater modules are disconnected from the drive voltage generated in process 172.

[0115] Figure 18 is a block diagram of a circuit according to one embodiment (indicated by reference numeral 180). Circuit 180 may be used to implement heater modules 164a, 164b, and 164n, respectively.

[0116] The circuit 180 includes a first switch 182, a second switch 183, and an RLC resonant circuit 184 (which includes an inductive element for inductively heating the susceptor device and one or more capacitors).

[0117] The first and second switches 182 and 183 are turned on (for example, in response to a control signal from the control module 166 described above) if the heater module is a selector heater module, and turned off if the heater module is not a selector heater module. The first and second switches may be bidirectional current switches.

[0118] Figure 19 shows a circuit (indicated collectively by reference numeral 190) used in several embodiments. Circuit 190 comprises a MOSFET and a freewheeling diode. Circuit 190 may also be used as the bidirectional current switch described above (e.g., first and second switches 182 and 183).

[0119] Figure 20 is a flowchart of an algorithm according to one embodiment (indicated overall by reference numeral 200). The algorithm 200 may be executed by a control module (e.g., a processor). For example, the algorithm 200 may be executed by the control module 117 of the system 110 described above or the control module 166 of the system 160 described above.

[0120] Algorithm 200 starts in process 202, where a control signal is provided. For example, the control signal may be provided from control module 117 to demultiplexer 112, or from control module 166 to first and second switching circuits 162 and 163.

[0121] In process 204, a feedback signal is received. For example, the feedback signal may be received by the control module 117 from the multiplexer 116, or by the control module 166 from the heater module 164.

[0122] Figure 21 is a block diagram of a system according to one embodiment (indicated by reference numeral 210). System 210 may be used to execute the algorithm 200 described above. System 210 may be used to implement control module 117 or control module 166.

[0123] The system 210 includes a processor 212, memory 214 (e.g., RAM or ROM), and may also include inputs or outputs 216. The processor 212 may be used to execute algorithm 200 based on computer program code stored in memory 214, for example.

[0124] The various embodiments described herein are presented solely to aid in the understanding and teaching of the features described in the claims. These embodiments are provided only as representative examples of the embodiments and are neither exhaustive nor 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 other embodiments may be used or modified without departing from the scope of the invention as described in the claims. Various embodiments of the present invention may appropriately comprise, have, or essentially comprise appropriate combinations of disclosed elements, parts, features, parts, processes, means, etc., other than those specifically described herein. Furthermore, this disclosure may include other inventions that are not currently described in the claims but may be described in the claims in the future.

Claims

1. A plurality of heater modules, each of which comprises a resonant circuit, the resonant circuit having an inductive element for inductively heating a susceptor device and one or more capacitors, and each of the plurality of heater modules further comprises a bridge circuit for selectively coupling a first side and a second side of each of the resonant circuits to positive and negative supply voltages, A demultiplexer device for providing a clock signal to one of the plurality of heater modules selected in response to a control signal received from a control module, A multiplexer device for providing a feedback signal from one of the selected heater modules, A device equipped with the following features.

2. The aforementioned demultiplexer device, An input for receiving the aforementioned clock signal, A control input for receiving the aforementioned control signal, Multiple outputs for selectively providing the clock signal to the multiple heater modules, The apparatus according to claim 1, comprising:

3. The aforementioned multiplexer device, Multiple inputs coupled to the feedback output of each of the multiple heater modules, A control input for receiving the aforementioned control signal, An output for providing the feedback signal from one of the selected heater modules, The apparatus according to claim 1 or 2, comprising:

4. The apparatus according to any one of claims 1 to 3, wherein the multiplexer device provides the feedback signal to the control module.

5. The apparatus according to any one of claims 1 to 4, further comprising the control module.

6. The apparatus according to any one of claims 1 to 5, further comprising a clock signal generator for generating the aforementioned clock signal.

7. The apparatus according to any one of claims 1 to 6, wherein the bridge circuit of each heater module provides alternating current to each of the resonant circuits under the control of the control circuit.

8. The apparatus according to any one of claims 1 to 7, wherein the bridge circuit of each heater module comprises two half-bridge circuits.

9. The apparatus according to any one of claims 1 to 8, wherein one or more capacitors in each of the heater modules include a tuning capacitor.

10. The apparatus according to claim 9, wherein each of the tuning capacitors has a capacitance set at least partially depending on the position of each of the heater modules within the apparatus.

11. The apparatus according to claim 9 or 10, wherein each tuning capacitor has a capacitance set in part with respect to one or more parameters that affect the resonant frequency of each heater module.

12. The apparatus according to any one of claims 1 to 11, which is an aerosol generating device or constitutes a part of an aerosol generating device.

13. An aerosol supply device comprising the apparatus described in any one of claims 1 to 12.

14. An aerosol supply system comprising the aerosol supply device according to claim 13 and an article containing an aerosol generating material.

15. The aerosol supply system according to claim 14, wherein the article comprises a susceptor.

16. A method for generating an aerosol, The steps of providing an aerosol supply system according to claim 14 or 15, The steps include: inserting the aerosol product at least partially into the chamber; A method for providing this.

17. The steps include providing a clock signal to one of several selected heater modules in response to a control signal received from the control module, The steps include providing a feedback signal from one of the selected heater modules, A method comprising: each heater module comprising a resonant circuit, the resonant circuit comprising an inductive element for inductively heating a susceptor device and one or more capacitors, and each of the plurality of heater modules further comprising a bridge circuit for selectively coupling a first side and a second side of each of the resonant circuits to positive and negative supply voltages.

18. The method according to claim 17, wherein the feedback signal is provided to the control module.

19. The method according to claim 17 or 18, further comprising the step of generating the clock signal.

20. The method according to any one of claims 17 to 19, further comprising the step of setting the capacitance of one or more capacitors in a manner that is at least partially dependent on the position of each of the heater modules.

21. A step of providing a control signal to a demultiplexer device, wherein the demultiplexer device is configured to provide a clock signal to one selected of a plurality of heater modules in response to the control signal, each of the heater modules comprising a resonant circuit, the resonant circuit comprising an inductive element for inductively heating a susceptor device and one or more capacitors, and each of the plurality of heater modules further comprising a bridge circuit for selectively coupling a first side and a second side of each of the resonant circuits to positive and negative supply voltages, A step of receiving a feedback signal from a multiplexer device, wherein the feedback signal is provided by one of the selected heater modules, A method for providing this.

22. The device includes at least, A step of providing a control signal to a demultiplexer device, wherein the demultiplexer device is configured to provide a clock signal to one selected of a plurality of heater modules in response to the control signal, each of the heater modules comprising a resonant circuit, the resonant circuit comprising an inductive element for inductively heating a susceptor device and one or more capacitors, and each of the plurality of heater modules further comprising a bridge circuit for selectively coupling a first side and a second side of each of the resonant circuits to positive and negative supply voltages, A step of receiving a feedback signal from a multiplexer device, wherein the feedback signal is provided by one of the selected heater modules, A computer program that contains instructions to execute something.

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