Apparatus for applying pulse and pulse edge to resonant circuit

Abstract

To provide an apparatus for applying pulses and pulse edges to a resonant circuit, and a method for controlling such an apparatus.SOLUTION: There is provided an apparatus that includes a bridge circuit for applying one or more pulse edges to a resonant circuit. The bridge circuit has a first limb in which a first connection point is connected to ground, and a second limb which has a third transistor connected between a first power source and a second connection point and a fourth transistor connected between the second connection point and ground. The resonant circuit includes an inductive element and a capacitor connected in series between the first and second connection points, the inductive element is for inductively heating a susceptor, each applied pulse edge induces a pulse response between the capacitor and the inductive element of the resonant circuit, and the pulse response has a resonant frequency.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present specification relates to an apparatus for applying pulses and pulse edges to a resonant circuit (eg, as part of an aerosol generating device), and a method for controlling such an apparatus. [Background technology]

[0002] (background) Smoking articles, such as cigarettes and cigars, burn tobacco during use to produce tobacco smoke. Attempts have been made to provide alternatives to these articles by creating products that release compounds without combustion. For example, tobacco heating devices heat an aerosol-generating substrate, such as tobacco, to form an aerosol by heating but not burning the substrate. Summary of the Invention

[0003] (overview) In a first aspect, the present specification describes an apparatus comprising a bridge circuit for applying one or more pulse edges to a resonant circuit, the bridge circuit (e.g., an H-bridge circuit) having a first limb with a first node connected to ground and a second limb with a third transistor connected between a first power supply and a second node and a fourth transistor connected between the second node and ground, the resonant circuit comprising an inductive element and a capacitor connected in series between the first and second nodes, the inductive element for inductively heating a susceptor, each applied pulse edge induces a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency. The apparatus may further comprise the resonant circuit.

[0004] The first limb of the bridge circuit may comprise a first transistor connected between the first power supply and the first node.

[0005] The first limb of the bridge circuit includes a second transistor connected between the first node and ground.

[0006] The capacitor of the resonant circuit may be connected to the first node, and the inductive element of the resonant circuit may be connected to the second node.

[0007] Some exemplary embodiments further include an output node between the inductive element and the capacitor of the resonant circuit. An output circuit (e.g., a DC voltage regulation circuit, etc.) may be coupled (e.g., using an output capacitor) to the output node between the inductive element and the capacitor of the resonant circuit. The capacitor of the resonant circuit may be disposed between the first node and the output node, and the inductive element of the resonant circuit is disposed between the second node and the output node. The output circuit may include a comparator.

[0008] In a second aspect, the present specification describes an apparatus comprising: an H-bridge circuit for applying one or more pulse edges to a resonant circuit, the H-bridge circuit having a first limb with a first transistor connected between a first power supply and a first node and a second transistor connected between the first node and ground; a second limb with a third transistor connected between the first power supply and a second node and a fourth transistor connected between the second node and ground; the resonant circuit comprising an inductive element and a capacitor connected in series between the first and second nodes, the inductive element for inductively heating a susceptor; each applied pulse edge induces a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency; an output circuit for providing an output signal in response to one or more characteristics of the pulse response; and an output capacitor connected between an output node between the inductive element and the capacitor of the resonant circuit and an input of the output circuit. The apparatus may further comprise the resonant circuit. The capacitor of the resonant circuit may be disposed between the first node and the output node. The inductive element of the resonant circuit may be provided between the second node and the output node. The output circuit may include a DC voltage regulation circuit. The output circuit may include a comparator.

[0009] The apparatus of either the first or second aspect may be operable in a heating mode of operation in which one or more pulses are applied to the inductive element to inductively heat the susceptor.

[0010] In a third aspect, the specification describes a method comprising the steps of selecting between a measurement mode and a heating mode of operation of a resonant circuit, the resonant circuit comprising an inductive element and a capacitor connected in series between first and second nodes of a bridge circuit; configuring the bridge circuit in a half-bridge mode if the measurement mode is selected, and configuring the bridge circuit in a full-bridge mode if the heating mode of operation is selected, the bridge circuit comprising a first limb having a first node, a second limb having a second node, a third transistor connected between the first power supply and the second node, and a fourth transistor connected between the second node and ground.

[0011] Configuring the bridge circuit in a half-bridge mode may include configuring the bridge circuit such that the first node is connected to ground, and the half-bridge mode may be implemented by switching the third and fourth transistors that form the second limb.

[0012] The first limb may include a second transistor connected between the first node and ground, and configuring the bridge circuit in half-bridge mode may include switching the second transistor (connected between the first node and ground) into a conductive state.

[0013] The first limb may include a first transistor connected between the first power supply and the first node, and a second transistor connected between the first node and ground.

[0014] The method may further include applying one or more pulse edges to the resonant circuit in a measurement mode of operation, each applied pulse edge inducing a pulse response between a capacitor and an inductive element of the resonant circuit, the pulse response having a resonant frequency.

[0015] The method may further include applying one or more pulses to the inductive element to inductively heat the susceptor in a heating mode of operation.

[0016] In a fourth aspect, the present specification describes a non-combustion aerosol-generating device comprising the apparatus described above with reference to the first or 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.

[0017] In a fifth aspect, the present specification describes a kit of parts including an article for use in a non-combustion aerosol generating system, the non-combustion aerosol generating system comprising an apparatus as described above with reference to the first or second aspects or an aerosol generating device as described above with reference to the fourth aspect. The article may be a removable article comprising an aerosol-generating material. [Brief explanation of the drawings]

[0018] Exemplary embodiments will now be described, by way of example only, with reference to the following schematic drawings: [Figure 1] FIG. 1 is a block diagram of a system in accordance with an illustrative embodiment. [Figure 2] 1 illustrates a non-combustible aerosol delivery device according to an exemplary embodiment. [Figure 3] 1 is a diagram of a non-combustible aerosol delivery device according to an exemplary embodiment. [Figure 4]1 is a diagram of an article for use with a non-combustible aerosol delivery device according to an exemplary embodiment. [Figure 5] FIG. 2 is a block diagram of a circuit in accordance with an exemplary embodiment. [Figure 6] FIG. 1 illustrates a resonant circuit in accordance with an exemplary embodiment. [Figure 7] FIG. 2 is a block diagram of a circuit in accordance with an exemplary embodiment. [Figure 8] FIG. 1 is a block diagram of a system in accordance with an illustrative embodiment. [Figure 9] FIG. 2 is a block diagram of a circuit in accordance with an exemplary embodiment. [Figure 10] 1 is a flowchart illustrating an algorithm according to an exemplary embodiment. [Figure 11] 1 is a plot illustrating an example use case of an exemplary embodiment; [Figure 12] 1 is a plot illustrating an example use case of an exemplary embodiment; [Figure 13] FIG. 2 is a block diagram of a circuit in accordance with an exemplary embodiment. [Figure 14] FIG. 2 is a block diagram of a circuit in accordance with an exemplary embodiment. [Figure 15] 1 is a flowchart illustrating an algorithm according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] (Detailed explanation) As used herein, the term "aerosol delivery device" is intended to encompass systems that deliver a substance to a user, including: Non-combustion aerosol delivery systems that release compounds from aerosolizable materials without burning the aerosolizable material, such as electronic cigarettes, tobacco heating products, and hybrid systems that use a combination of aerosolizable materials to generate aerosols; and An article that includes an aerosolizable material and is configured for use in one of these non-combustible aerosol delivery systems.

[0020] According to this disclosure, a "combustible" aerosol delivery system is one in which the aerosolizable material comprising the aerosol delivery system (or its components) is combusted or burned to facilitate delivery to a user.

[0021] According to the present disclosure, a "non-combustion" aerosol delivery system is one in which the aerosolizable material comprising the aerosol delivery system (or its components) is not combusted or burned to facilitate delivery to a user. In embodiments described herein, the delivery system is a non-combustion aerosol delivery system, e.g., a powered non-combustion aerosol delivery system.

[0022] In one embodiment, the non-combustible aerosol delivery system is an e-cigarette, also known as a vaping device or electronic nicotine delivery system (END), although it should be noted that the presence of nicotine in the aerosolizable material is not a requirement.

[0023] In one embodiment, the non-combustion aerosol delivery system is a tobacco heating system, also known as a non-combustion heating system.

[0024] In one embodiment, the non-combustion aerosol delivery system is a hybrid system that generates an aerosol using a combination of aerosolizable materials, one or more of which may be heated. Each of the aerosolizable materials may be, for example, in solid, liquid, or gel form 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 a non-tobacco product.

[0025] Typically, a non-combustion aerosol delivery system may include a non-combustion aerosol delivery device and an article for use with the non-combustion aerosol delivery system, however, it is also contemplated that an article that itself includes a means for powering an aerosol generating component may itself form a non-combustion aerosol delivery system.

[0026] In one embodiment, the non-combustible aerosol delivery device may include a power source and a controller. The power source may be an electrical source or a heat-generating power source. In one embodiment, the heat-generating power source includes a carbon substrate that can be energized to provide power in the form of heat to an aerosolizable material or heat transfer material in proximity to the heat-generating power source. In one embodiment, a power source, such as a heat-generating power source, is provided within the article to form the non-combustible aerosol delivery.

[0027] In one embodiment, an article for use with a non-combustible aerosol delivery device may include an aerosolizable material, an aerosol-generating component, an aerosol-generating region, a mouthpiece, and / or a region for receiving the aerosolizable material.

[0028] In one embodiment, the aerosol-generating component is a heater capable of interacting with the aerosolizable material to release one or more volatile substances from the aerosolizable material to form an aerosol. In one embodiment, the aerosol-generating component is capable of generating an aerosol from the aerosolizable material without the application of heat. For example, the aerosol-generating component may be capable of generating an aerosol from the aerosolizable material without the application of heat, such as by one or more of vibrational, mechanical, pressurized, or electrostatic means.

[0029] In one embodiment, the aerosolizable material may include an active material, an aerosol-forming material, and optionally one or more functional materials. The active material may include nicotine (optionally contained in tobacco or a tobacco derivative) or one or more other non-olfactory bioactive materials. A non-olfactory bioactive material is a material included in the aerosolizable material to achieve a physiological response other than olfaction. As used herein, an active substance may be a bioactive material, which is a material intended to achieve or enhance a physiological response. The active substance may be selected from, for example, a dietary supplement, a nootropic, or a psychoactive substance. The active substance may be naturally occurring or synthetically derived. The active substance may include, for example, nicotine, caffeine, taurine, theine, vitamins such as B6, B12, or C, melatonin, cannabinoids, or components, derivatives, or combinations thereof. The active substance may include 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 agent comprises caffeine, melatonin, or vitamin B12.

[0030] The aerosol-forming material may include one or more of 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 mixtures, benzyl benzoate, benzyl phenylacetate, tributyrin, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

[0031] The one or more functional ingredients may include one or more of a fragrance, a carrier, a pH adjuster, a stabilizer, and / or an antioxidant.

[0032] In one embodiment, an article for use with a non-combustible aerosol delivery device may include an aerosolizable material or an area for receiving an aerosolizable material. In one embodiment, an article for use with a non-combustible aerosol delivery device may include a mouthpiece. The area for receiving an aerosolizable material may be a storage area for storing the aerosolizable material. For example, the storage area may be a reservoir. In one embodiment, the area for receiving an aerosolizable material may be separate from the aerosol-generation area or may be combined with the aerosol-generation area.

[0033] An aerosolizable material, sometimes referred to herein as an aerosol-generating material, is a material capable of generating an aerosol, for example, when heated, irradiated, or otherwise energized. The aerosolizable material may be in the form of a solid, liquid, or gel, which may or may not contain nicotine and / or flavorings, for example. In some embodiments, the aerosolizable material may comprise an "amorphous solid," which may alternatively be referred to as a "monolithic solid" (i.e., non-fibrous). In some embodiments, the amorphous solid may be a dry gel. An amorphous solid is a solid material that can hold some fluid, such as a liquid, within it.

[0034] The aerosolizable material may be present on a substrate, which may be or include, for example, paper, card, paperboard, cardboard, recycled aerosolizable material, plastic material, ceramic material, composite material, glass, metal, or metal alloy.

[0035] A consumable is an article containing or consisting of an aerosol-generating material, intended to be consumed in part or in whole by a user during use. A consumable may 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. A consumable may also include an aerosol generator, such as a heater, that emits heat to cause the aerosol-generating material to generate an aerosol upon use. The heater may include, for example, a combustible material, a material heatable by electrical conduction, or a susceptor.

[0036] 1 is a block diagram of a system according to an exemplary embodiment, generally designated by the reference numeral 10. System 10 includes a power source in the form of a direct current (DC) voltage source 11, a switching arrangement 13, a resonant circuit 14, a susceptor arrangement 16, and a control circuit 18. Switching arrangement 13 and resonant circuit 14 may be coupled together in an induction heating arrangement 12 that can be used to heat susceptor 16.

[0037] As discussed in more detail below, resonant circuit 14 may include a capacitor and one or more inductive elements for inductively heating susceptor structure 16 to heat the aerosol-forming material. Heating the aerosol-forming material may generate an aerosol.

[0038] The switching arrangement 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 and cause heating of the susceptor arrangement 16. The switching arrangement may include multiple transistors. Examples of DC-AC converters include an H-bridge circuit or an inverter circuit, examples of which are discussed below.

[0039] The susceptor is a material that can be heated by the penetration of a varying magnetic field, such as an alternating magnetic field. The heating material can be a conductive material, which causes induction heating of the heating material when the varying magnetic field penetrates it. The heating material can be a magnetic material, which causes magnetic hysteresis heating of the heating material when the varying magnetic field penetrates it. The heating material can be both conductive and magnetic, which allows the heating material to be heated by both heating mechanisms.

[0040] Induction heating is a process in which a conductive object is heated by penetrating a changing magnetic field into the object. This process is explained by Faraday's law of electromagnetic induction and Ohm's law. An induction heater may include an electromagnet and a device for passing a changing current, such as an alternating current, through the electromagnet. When the electromagnet and the object to be heated are appropriately positioned relative to one another, one or more eddy currents are generated within the object when the changing magnetic field generated by the electromagnet penetrates the object. The object has resistance to the flow of current. Therefore, when such eddy currents are generated within the object, they flow against the object's electrical resistance, causing the object to heat. This process is also known as Joule heating, ohmic heating, or resistive heating. An object that can be inductively heated is known as a susceptor.

[0041] 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 during use is enhanced, resulting in greater or improved Joule heating.

[0042] Magnetic hysteresis heating is a process in which an object made of a magnetic material is heated by subjecting the object to a varying magnetic field. Magnetic materials can be thought of as consisting of a large number of 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. Thus, when a varying 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 varying magnetic field. This change in orientation of the magnetic dipoles generates heat within the magnetic material.

[0043] If an object is both conductive and magnetic, then subjecting the object to a varying magnetic field can cause both Joule heating and magnetic hysteresis heating in the object. Furthermore, the use of magnetic materials can enhance the magnetic field, thereby increasing Joule heating.

[0044] Because the heat is generated within the object itself, rather than by an external heat source via thermal conduction, each of the above processes can achieve rapid temperature rise and more uniform heat distribution in the object, particularly by selecting the appropriate object material and shape and the appropriate magnitude and orientation of the varying magnetic field relative to the object. Furthermore, induction heating and magnetic hysteresis heating do not require a physical connection between the source of the varying magnetic field and the object, which may allow for greater design freedom and control of the heating profile, and may lower costs.

[0045] 2 and 3 illustrate a non-combustion aerosol delivery device according to an exemplary embodiment, generally designated by reference numeral 20. FIG. 2 is a perspective view of aerosol delivery device 20A with an outer cover attached. Aerosol delivery device 20A may include a replaceable item 21, which may be inserted into aerosol delivery device 20A to heat a susceptor (which may be included in item 21, as discussed further below). Aerosol delivery device 20A may further include an activation switch 22, which may be used to turn aerosol delivery device 20A on or off.

[0046] 3 shows aerosol delivery device 20B with the outer cover removed. Aerosol generation device 20B includes article 21, activation switch 22, multiple inductive elements 23a, 23b, and 23c, and one or more air tube extenders 24 and 25. One or more of air tube extenders 24 and 25 may be optional.

[0047] Each of the multiple inductive elements 23a, 23b, and 23c may form part of a resonant circuit, such as the resonant circuit 14. The inductive element 23a may include a helical inductor coil. In one example, the helical inductor coil is made from a Litz wire / cable wound in a spiral to provide the helical inductor coil. Many alternative inductor configurations are possible, for example, an inductor formed in a printed circuit board. The inductive elements 23b and 23c may be similar to the inductive element 23a. The use of three inductive elements 23a, 23b, and 23c is not required for all exemplary embodiments. Thus, the aerosol generation device 20 may include one or more inductive elements.

[0048] The susceptor may be provided as part of the article 21. In an exemplary embodiment, when the article 21 is inserted into the aerosol generation device 20, the insertion of the article 21 may cause the aerosol generation device 20 to be turned on. This may be, for example, by detecting the presence of the article 21 in the aerosol generation device using a suitable sensor (e.g., an optical sensor), or, if the susceptor forms part of the article 21, by detecting the presence of the susceptor using the resonant circuit 14. When the aerosol generation device 20 is turned on, the inductive element 23 may cause the article 21 to be inductively heated via the susceptor. In an alternative embodiment, the susceptor may be provided as part of the aerosol generation device 20 (e.g., as part of a holder for receiving the article 21).

[0049] 4 is a diagram of an article for use with a non-combustible aerosol delivery device according to an exemplary embodiment, generally designated by reference numeral 30. Item 30 is an example of replaceable item 21 described above with reference to FIGS.

[0050] Article 30 includes a mouthpiece 31 and a cylindrical rod of aerosol-forming material 33, in this case tobacco material, connected to mouthpiece 31. Aerosol-forming material 33 provides an aerosol when heated in a non-combustion aerosol-generating device, such as aerosol-generating device 20 described herein. Aerosol-generating material 33 is enclosed in wrapper 32. Wrapper 32 may be, for example, a paper or paper-lined foil wrapper. Wrapper 32 may be substantially impermeable to air.

[0051] In one embodiment, the wrapper 32 comprises aluminum foil. Aluminum foil has been found to be particularly effective at promoting aerosol formation within the aerosol-generating material 33. In one example, the aluminum foil has a metal layer having a thickness of approximately 6 μm. The aluminum foil may have a paper backing. However, in alternative configurations, the aluminum foil may have other thicknesses, for example, between 4 μm and 16 μm. The aluminum foil need not 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 have no backing material at all. Metal layers or foils other than aluminum may also be used. Furthermore, it is not necessary for such metal layers to be provided as part of the article 30; for example, such metal layers may be provided as part of the device 20.

[0052] The aerosol-forming 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 can be any other material described herein or a combination thereof. The aerosol-forming material has been found to improve the sensory performance of the article by aiding in the transfer of compounds, such as fragrance compounds, from the aerosol-generating material to the consumer.

[0053] As shown in Figure 4, the mouthpiece 31 of the article 30 includes an upstream end 31a adjacent the aerosol-forming substrate 33 and a downstream end 31b remote from the aerosol-forming substrate 33. The aerosol-forming substrate may comprise tobacco, although alternatives are possible.

[0054] The mouthpiece 31 includes a body of material 36 upstream of the hollow tubular element 34, which in this example is adjacent to and in abutting relationship with the hollow tubular element 34. The body of material 36 and the hollow tubular element 34 each define a substantially cylindrical overall outer shape and share a common longitudinal axis. The body of material 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 about 20 gsm and 40 gsm.

[0055] 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 referred to as a cooling element, upstream of the first hollow tubular element 34. In this example, the second hollow tubular element 38 is upstream of, adjacent to, and in abutting relationship with the body of material 36. The body of material 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 paper layers that are wound in parallel and joined at seams to form the tubular element 38. In this example, the first and second paper layers are arranged in a double tube, but in other embodiments, three, four, or more paper layers can be used to form a triple, quadruple, or more layer tube. Other constructions can also be used, such as spirally wound paper layers, cardboard tubes, tubes formed using a paper-mâché-type process, and molded or extruded plastic tubes. The second hollow tubular element 38 can also be formed using stiff plug wrap and / or tipping paper as the second plug wrap 39 and / or tipping paper 35 described herein, meaning that a separate tubular element is not required.

[0056] The second hollow tubular element 38 surrounds and defines a cavity within the mouthpiece 31 that functions as a cooling segment. The cavity 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 to provide a chamber for aerosol accumulation, yet 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 body of material 36. The physical displacement provided by the second hollow tubular element 38 provides a temperature gradient across the length of the second hollow tubular element 38.

[0057] Of course, item 30 is provided by way of example only, and those skilled in the art will recognize many alternative configurations of such items that may be used in the systems described herein.

[0058] 5 is a block diagram of a circuit according to an exemplary embodiment, generally designated by reference numeral 50. 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 through fourth switches 51 through 54 may be implemented using transistors, as discussed further below.

[0059] The first to fourth switches 51 to 54 form an H-bridge circuit that may be used to apply pulses to the resonant circuit 56. As such, the first to fourth switches 51 to 54 are an example implementation of the switching arrangement 13, and the resonant circuit 56 is an example of the resonant circuit 14.

[0060] The first and second switches 51 and 52 form a first limb of a bridge circuit, and the third and fourth switches 53 and 54 form a second limb. More specifically, the first switch 51 is connected to a first power supply (V DD A second switch 52 can selectively provide a connection between the first connection point and ground, 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.

[0061] 6 is an example implementation of the above-described resonant circuit 56. The resonant circuit 56 includes a series connection of a capacitor 61 and an inductor 62 that may be connected between the first and second connection points of the above-described system 50. As described further below, the inductor may be used to inductively heat a susceptor (e.g., susceptor 16 of system 10).

[0062] 7 is a block diagram of a circuit according to an exemplary embodiment, generally designated by reference numeral 70. Circuit 70 is an implementation of circuit 50 described above.

[0063] System 70 includes a positive terminal 77 and a negative (ground) terminal 78 (which are an implementation of DC voltage source 11 of system 10 described above). Circuit 70 includes a switching component 74 (implementing switching component 13 described above), which includes a bridge circuit (e.g., an H-bridge circuit, such as a FET H-bridge circuit). Switching component 74 includes a first limb 74a and a second limb 74b, which are coupled by a resonant circuit 79 (which implements resonant circuits 14 and 56 described above). First limb 74a includes switches 75a and 75b (implementing switches 51 and 52 described above), and second limb 74b includes switches 75c and 75d (implementing switches 53 and 54 described above). Switches 75 a , 75 b , 75 c , and 75 d may be transistors, such as field effect transistors (FETs), and may receive input from a controller, such as control circuit 18 of system 10 .

[0064] Resonant circuit 79 includes a capacitor 76 and an inductive element 73, such that resonant circuit 79 is an LC resonant circuit. Circuit 70 further illustrates a susceptor equivalent circuit 72 (which implements susceptor structure 16). Susceptor equivalent circuit 72 includes a resistive and an inductive element that represent the electrical effects of the exemplary susceptor structure 16. When a susceptor is present, susceptor structure 72 and inductive element 73 may function as a transformer 71. Transformer 71 may generate a varying magnetic field that heats the susceptor when circuit 70 receives power. During a heating operation, in which susceptor structure 16 is heated by the inductive structure, switching structure 74 is driven (e.g., by control circuit 18) such that each of the first and second branches is coupled in turn to cause an alternating current to flow through resonant circuit 79. The resonant circuit 79 may have a resonant frequency based in part on the susceptor structure 16, and the control circuit 18 may be configured to control the switching structure 74 to switch at or near the resonant frequency. Driving the switching structure at or near resonance helps improve efficiency, reducing energy lost to the switching elements (which can cause unnecessary heating of the switching elements). In one example in which an article 21 including aluminum foil is heated, the switching structure 84 may be driven at a frequency near 2.5 MHz. However, in other implementations, the frequency may be anywhere between 500 kHz and 4 MHz, for example.

[0065] FIG. 8 is a block diagram of a system, generally designated by the reference numeral 80, in accordance with an exemplary embodiment.

[0066] System 80 includes a pulse generating circuit 82, a resonant circuit 84 (such as, for example, resonant circuit 56), a susceptor 86 (such as, for example, susceptor 16), and a pulse response processor 88. Pulse generating circuit 82 and pulse response processor 84 may be implemented as part of control circuit 18 of system 10.

[0067] Pulse generating circuit 82 may be implemented using the switching components of systems 50 and 70 described above to generate pulses (eg, pulse edges) by switching between positive and negative voltage sources.

[0068] Based on the pulse response, the pulse response processor 88 may determine one or more performance metrics (or characteristics) of the resonant circuit 84 and the susceptor 86. Such performance metrics may include characteristics of the article (e.g., removable article 21), the presence or absence of such an article, the type of article, the operating temperature, etc.

[0069] The pulse response obtained by the pulse response processor 88 may contain noise. There are many possible sources of noise, but one source is differences in the switching timing of the pulse generating circuit 82. A low-pass filter function may be provided to try to reduce such noise.

[0070] In some exemplary embodiments, one of switches 52 and 54 (or one of transistors 75b and 75d) may be permanently on, connecting one side of resonant circuit 56 to ground, which provides a low-pass filter effect that can reduce noise in the pulse response.

[0071] 9 is a block diagram of a circuit, generally designated by the reference numeral 90, according to an exemplary embodiment. Circuit 90 includes capacitor 61 and inductive element 62 of resonant circuit 56 described above. An output node, generally designated by the reference numeral 64, is provided between the inductive element and the capacitor of the resonant circuit. An output capacitor 92 is used to couple output node 64 to output circuit 94.

[0072] 10 is a flow chart illustrating an algorithm according to an exemplary embodiment, generally designated by the reference numeral 100. The algorithm 100 illustrates an example use of the system 80.

[0073] Algorithm 100 begins with operation 102, where a pulse edge (generated by pulse generating circuit 82) is applied to resonant circuit 84. Figure 11 is a plot illustrating an exemplary pulse 110 (including a rising pulse edge 112) that may be applied in operation 102.

[0074] The pulse 110 may be applied to the resonant circuit 84. Alternatively, in a system having multiple inductive elements (such as the non-combustible aerosol construction 20 described above with reference to FIGS. 2 and 3), the pulse generating circuit 82 may select one of multiple resonant circuits, each including an inductive element and a capacitor for inductively heating a susceptor, and the applied pulse induces a pulse response between the capacitor and the inductive element of the selected resonant circuit.

[0075] In operation 104, an output is generated (by pulse response processor 88) based on the pulse response generated in response to the pulse applied in operation 102. The pulse response may be the output of output circuitry 94.

[0076] FIG. 12 is a plot generally designated by the reference numeral 120 illustrating an exemplary pulse response 122 that may be generated at junction 64 between capacitor 61 and inductor 62 of resonant circuit 64 in response to pulse 110. As shown in FIG. 12, pulse response 122 may take the form of a ringing resonance generated in response to the pulse edge. The pulse response is the result of charge bouncing between the inductor(s) and capacitor of resonant circuit 56. In one configuration, no heating of the susceptor results; 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).

[0077] Plot 120 shows a second pulse response 124 that may be produced by output circuitry 94. Second pulse response 124 may be a pulse that is provided to pulse response processor 88.

[0078] 13 is a block diagram of a circuit according to an exemplary embodiment, generally designated by reference numeral 130. Circuit 130 is an implementation of output circuit 94 described above.

[0079] The circuit 130 includes an output capacitor 92 that is used to couple the output node 64 to the output circuit 94 as described above. The circuit 130 also includes a signal conditioning circuit 132 and a comparator 134. The signal conditioning circuit 132 includes a first limb including a first resistor R1 and a second resistor R2 in parallel with a second limb including a first diode D1 and a second diode D2. The signal conditioning circuit may be used to implement a DC voltage regulation function.

[0080] The signal conditioning circuit 130 has at least three purposes. First, it provides protection from voltage spikes. This is achieved by stacking diodes and a resistor (not shown) between the midpoint of the diodes and the output. Second, it provides signal decoupling, which is the purpose of the output capacitor 92 mentioned above. Third, it sets the offset voltage of the pulse response at the output node 64.

[0081] The output of signal conditioning circuit 130 may be provided to comparator 134. The offset voltage set by the signal conditioning circuit may be configured to match that of the comparator's input, causing the comparator to trigger in the middle of the pulse response. This is achieved using resistors R1 and R2.

[0082] At least some of the characteristics of the pulse response (e.g., the frequency and / or decay rate of the pulse response, etc.) provide information about the system to which the pulse is applied. Thus, system 80 can be used to determine one or more characteristics of the system to which the pulse is applied. For example, one or more performance characteristics, such as a fault condition, characteristics of an inserted item 21, the presence or absence of such an item, whether the item 21 is authentic, operating temperature, etc., can be determined based on an output signal derived from the pulse response.

[0083] As mentioned above, the pulse response obtained by pulse response processor 88 may contain noise. One approach to reducing noise is to permanently turn on (i.e., conduct) one of switches 52 and 54 (or one of transistors 75b and 75d) so that one side of resonant circuit 56 is connected to ground. Another approach is to replace one of the switches with a permanent connection to ground, as shown in FIG. 14.

[0084] 14 is a block diagram of a circuit according to an exemplary embodiment, generally designated by reference numeral 140. Circuit 140 includes the third switch 53, the fourth switch 54, and the resonant circuit 56 of circuit 50 described above. Additionally, the first node (between the first switch 51 and the resonant circuit 56) is connected to ground. Thus, the second switch 52 of circuit 50 is replaced with a permanent connection to ground.

[0085] The circuit 50 described above provides a full-bridge circuit for driving the resonant circuit 56. The circuit 140 provides a half-bridge circuit for driving the resonant circuit 56. For example, the circuit 50 may be particularly suitable for providing pulses for driving the resonant circuit for inductively heating a susceptor, and the circuit 140 may be particularly suitable for providing pulse edges for generating a pulse response from the resonant circuit for analysis (e.g., measurement).

[0086] In some exemplary embodiments, the bridge circuit can be controlled to operate in either a measurement mode (in which pulse edges can be applied to the resonant circuit) or a heating mode (in which pulses can be applied to the resonant circuit to inductively heat the susceptor). As described further below, in the measurement mode, the bridge circuit can be configured in a half-bridge mode including the low-pass filtering arrangement described above (e.g., using circuit 140 or some similar configuration), and in the heating mode, the bridge circuit can be configured in a full-bridge mode (e.g., using circuit 50 or some similar configuration).

[0087] FIG. 15 is a flowchart illustrating an algorithm, generally designated by the reference numeral 150, according to an exemplary embodiment.

[0088] The algorithm 150 begins at operation 152, where a selection is made between a measurement mode and a heating mode of operation of a resonant circuit (such as, for example, resonant circuit 56 described above).

[0089] In operation 154, the bridge circuit is configured according to the mode of operation selected in operation 152. Specifically, the bridge circuit is configured in half-bridge mode if the measurement mode is selected, and in full-bridge mode if the heating mode of operation is selected.

[0090] As described above, the bridge circuit includes a first limb having a first connection point, a second limb having a second connection point, a third transistor connected between the first power supply and the second connection point, and a fourth transistor connected between the second connection point and ground.

[0091] In half-bridge mode, the bridge circuit is configured (as in circuit 140 described above) with the first node connected to ground so that the low-pass filtering arrangement described above is effective. As discussed above, the first limb may include a second transistor connected between the first node and ground. Thus, configuring the bridge circuit in half-bridge mode may include switching the second transistor (of the first limb) into a conductive state while alternately switching the third and fourth transistors (of the second limb).

[0092] More specifically, the first limb may have a first transistor connected between a first power supply and a first node (as in circuit 50 described above) and a second transistor connected between the first node and ground, with the first and second transistors of the first limb (and the third and fourth transistors of the second limb) switched to implement full-bridge mode, and only the transistors of the second limb switched during half-bridge mode.

[0093] In operation 156, one or more pulses or pulse edges are applied to the resonant circuit using the configured bridge circuit. In a measurement mode of operation, one or more pulse edges are applied to induce a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency (which may be the measured value). In a heating mode of operation, one or more pulses to the inductive element to inductively heat the susceptor in the heating mode of operation.

[0094] The various embodiments described herein are presented solely to aid in the understanding and teaching of the claimed features. These embodiments are provided only as a representative sample of embodiments and are not intended to be exhaustive and / or exclusive. The advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein should not be construed as limitations on the scope of the invention as defined by the claims or on the equivalents of the claims, and it should be understood that other embodiments may be utilized and changes may be made without departing from the scope of the claimed invention. The various embodiments of the present invention may suitably comprise, consist of, or consist essentially of any suitable combination of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. Furthermore, the present disclosure may include other inventions not currently claimed but that may be claimed in the future.

Claims

1. 1. A bridge circuit for applying one or more pulse edges to a resonant circuit, the bridge circuit having a first limb with a first node connected to ground and a second limb with a third transistor connected between a first power supply and a second node and a fourth transistor connected between the second node and ground, the resonant circuit comprising an inductive element and a capacitor connected in series between the first and second nodes, the inductive element for inductively heating a susceptor, each applied pulse edge causing a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency. An apparatus comprising:

2. 2. The apparatus of claim 1, wherein the bridge circuit is an H-bridge circuit.

3. 3. The apparatus of claim 1, wherein the first limb of the bridge circuit comprises a first transistor connected between the first power supply and the first node.

4. 4. Apparatus according to any one of claims 1 to 3, wherein the first limb of the bridge circuit comprises a second transistor connected between the first node and ground.

5. 5. The device according to claim 1, wherein the capacitor of the resonant circuit is connected to the first connection point and the inductive element of the resonant circuit is connected to the second connection point.

6. The apparatus of any one of claims 1 to 5, further comprising an output connection point between the inductive element and the capacitor of the resonant circuit.

7. 7. The apparatus of claim 6, further comprising an output circuit coupled to the output node between the inductive element and the capacitor of the resonant circuit.

8. 8. The apparatus of claim 7, wherein the output circuit and the output node are coupled using an output capacitor.

9. 9. The device according to claim 6, wherein the output circuit is a DC voltage regulation circuit.

10. Apparatus according to any one of claims 6 to 9, wherein the output circuit comprises a comparator.

11. 11. The device according to claim 6, wherein the capacitor of the resonant circuit is provided between the first connection point and the output connection point, and the inductive element of the resonant circuit is provided between the second connection point and the output connection point.

12. an H-bridge circuit for applying one or more pulse edges to a resonant circuit, the H-bridge circuit having a first limb having a first transistor connected between a first power supply and a first node and a second transistor connected between the first node and ground, and a second limb having a third transistor connected between the first power supply and a second node and a fourth transistor connected between the second node and ground, the resonant circuit comprising an inductive element and a capacitor connected in series between the first and second nodes, the inductive element for inductively heating a susceptor, each applied pulse edge causing a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency; an output circuit for providing an output signal in response to one or more characteristics of the pulse response; an output capacitor connected between an output connection point between the inductive element and the capacitor of the resonant circuit and an input of the output circuit; An apparatus comprising:

13. 13. The apparatus of claim 12, wherein the capacitor of the resonant circuit is disposed between the first connection point and the output connection point, and the inductive element of the resonant circuit is disposed between the second connection point and the output connection point.

14. 14. Apparatus according to claim 12 or 13, wherein the output circuit comprises a DC voltage regulation circuit.

15. Apparatus according to any one of claims 12 to 14, wherein the output circuit comprises a comparator.

16. Apparatus according to any one of the preceding claims, wherein the apparatus is operable in a heating mode of operation in which one or more pulses are applied to the inductive element to inductively heat the susceptor.

17. The apparatus of any one of claims 1 to 16, further comprising the resonant circuit.

18. selecting between a measurement mode and a heating mode of operation of a resonant circuit, the resonant circuit comprising an inductive element and a capacitor connected in series between first and second nodes of a bridge circuit; configuring the bridge circuit in a half-bridge mode when the measurement mode is selected, and configuring the bridge circuit in a full-bridge mode when the heating mode of operation is selected, the bridge circuit comprising a first limb having the first node, a second limb having the second node, a third transistor connected between a first power supply and the second node, and a fourth transistor connected between the second node and ground; A method comprising:

19. 20. The method of claim 18, wherein configuring the bridge circuit in the half-bridge mode includes configuring the bridge circuit such that the first node is connected to ground.

20. 20. The method of claim 18 or 19, wherein the first limb comprises a second transistor connected between the first node and ground, and wherein configuring the bridge circuit in the half-bridge mode comprises switching the second transistor into a conductive state.

21. 21. The method of any one of claims 18 to 20, wherein the first limb comprises a first transistor connected between the first power supply and the first node, and a second transistor connected between the first node and ground.

22. 22. The method of any one of claims 18 to 21, further comprising applying one or more pulse edges to the resonant circuit in the measurement mode of operation, each applied pulse edge inducing a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency.

23. The method of any one of claims 18 to 22, further comprising applying one or more pulses to the inductive element for inductively heating a susceptor in the heating mode of operation.

24. A non-combustion aerosol generating device comprising the apparatus according to any one of claims 1 to 17.

25. 25. The non-combustion aerosol generating device of claim 24, wherein the aerosol generating device is configured to receive a removable article containing an aerosol-generating material.

26. 26. The non-combustion aerosol-generating device according to claim 25, wherein the aerosol-generating material comprises an aerosol-generating substrate and an aerosol-forming material.

27. 27. The non-combustion aerosol generating device according to claim 25 or 26, wherein the removable article comprises a susceptor structure.

28. A kit of parts comprising articles for use in a non-combustion aerosol generating system, the non-combustion aerosol generating system comprising an apparatus according to any one of claims 1 to 17 or an aerosol generating device according to any one of claims 24 to 27.

29. 30. The kit of parts of claim 28, wherein the article is a removable article containing an aerosol-forming material.

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