Apparatus for applying pulses and pulse edges to a resonant circuit

Abstract

1. An apparatus comprising: a bridge circuit for applying one or more pulse edges to a resonant circuit, the bridge circuit having a first limb having a first node connected to ground and a second limb having 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.

Description

Technical Field

[0001] This specification relates to an apparatus for applying pulses and pulse edges to a resonant circuit (e.g., as part of an aerosol generating device), and a method for controlling such an apparatus.

Background Art

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

Summary of the Invention

[0003] (Summary) In a first aspect, this specification describes a 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 connection point connected to ground, and a second limb having a third transistor connected between a first power supply and a second connection point and a fourth transistor connected between the second connection point and ground, the resonant circuit comprising an inductor and a capacitor connected in series between the first and second connection points, the inductor being for inductively heating a susceptor, each applied pulse edge causing a pulse response between the capacitor and the inductor of the resonant circuit, the pulse response having a resonant frequency, and the apparatus comprising the bridge circuit. This apparatus may further comprise the resonant circuit.

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

[0005] The first rim of the bridge circuit comprises a second transistor connected between the first connection point and ground.

[0006] The capacitor of the resonant circuit may be connected to the first connection point. The inductive element of the resonant circuit may be connected to the second connection point.

[0007] Some exemplary embodiments further include an output connection point between the inductor and capacitor of the resonant circuit. The output circuit (e.g., a DC voltage regulating circuit) may be coupled to the output connection point between the inductor and capacitor of the resonant circuit (e.g., using an output capacitor). The capacitor of the resonant circuit may be located between the first connection point and the output connection point, and the inductor of the resonant circuit may be located between the second connection point and the output connection point. The output circuit may include a comparator.

[0008] In a second embodiment, this specification describes an H-bridge circuit for applying one or more pulse edges to a resonant circuit, wherein the H-bridge circuit has a first rim having a first transistor connected between a first power supply and a first connection point and a second transistor connected between the first connection point and ground, and a second rim having a third transistor connected between a first power supply and a second connection point and a fourth transistor connected between the second connection point and ground, the resonant circuit comprises an inductive element and a capacitor connected in series between the first and second connection points, the inductive element for inductive heating of a susceptor, and each applied pulse edge causes a pulse response between the capacitor and the inductive element of the resonant circuit, the pulse response having a resonant frequency, the H-bridge circuit, the output circuit for providing an output signal according to one or more characteristics of the pulse response, and an output capacitor connected between the output connection point between the inductive element and the capacitor of the resonant circuit and the input of the output circuit. The device may further include the resonant circuit. The capacitor of the resonant circuit may be provided between the first connection point and the output connection point. The inductive element of the resonant circuit may be provided between the second connection point and the output connection point. The output circuit may include a DC voltage regulating circuit. The output circuit may also include a comparator.

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

[0010] In a third embodiment, this specification describes a method comprising the steps of: selecting a measurement mode and a heating mode in the operation of a resonant circuit, wherein the resonant circuit comprises an inductor and a capacitor connected in series between a first and a second connection point of a bridge circuit; configuring the bridge circuit in half-bridge mode when the measurement mode is selected; and configuring the bridge circuit in full-bridge mode when the heating mode in operation is selected, wherein the bridge circuit comprises a first rim having a first connection point, a second rim having a second connection point, a third transistor connected between a first power supply and the second connection point, and a fourth transistor connected between the second connection point and ground.

[0011] The step of configuring the bridge circuit in half-bridge mode may include configuring the bridge circuit such that the first connection point is connected to ground. Half-bridge mode may be achieved by switching the third and fourth transistors that form the second rim.

[0012] The first rim may include a second transistor connected between the first connection point and ground. The step of configuring the bridge circuit in half-bridge mode may include switching the second transistor (connected between the first connection point and ground) to a conducting state.

[0013] The first rim may include a first transistor connected between a first power supply and a first connection point, and a second transistor connected between the first connection point and ground.

[0014] This method may further include the step of applying one or more pulse edges to a resonant circuit in a measurement operation mode, each applied pulse edge causing a pulse response between the capacitor and inductor of the resonant circuit, the pulse response having a resonant frequency.

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

[0016] In a fourth embodiment, this specification describes a non-combustible aerosol generating device comprising the apparatus described above with reference to the first or second embodiment. 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, this specification describes a kit of components comprising articles for use in a non-combustible aerosol generating system, wherein the non-combustible aerosol generating system comprises the apparatus described above with reference to the first or second aspect, or the aerosol generating device described above with reference to the fourth aspect. The articles may be removable articles comprising aerosol generating material. [Brief explanation of the drawing]

[0018] Here, an exemplary embodiment will be described as merely an example with reference to the following schematic diagram. [Figure 1] This is a block diagram of a system according to an exemplary embodiment. [Figure 2] This figure shows a non-combustible aerosol supply device according to an exemplary embodiment. [Figure 3] This is a diagram of a non-combustible aerosol supply device according to an exemplary embodiment. [Figure 4]A diagram of an article for use with a non-combustible aerosol supply device according to an exemplary embodiment. [Figure 5] A block diagram of a circuit according to an exemplary embodiment. [Figure 6] A diagram showing a resonant circuit according to an exemplary embodiment. [Figure 7] A block diagram of a circuit according to an exemplary embodiment. [Figure 8] A block diagram of a system according to an exemplary embodiment. [Figure 9] A block diagram of a circuit according to an exemplary embodiment. [ [Figure 10] A flowchart showing an algorithm according to an exemplary embodiment. [Figure 11] A plot showing an example of use of an exemplary embodiment. [Figure 12] A plot showing an example of use of an exemplary embodiment. [Figure 13] A block diagram of a circuit according to an exemplary embodiment. [Figure 14] A block diagram of a circuit according to an exemplary embodiment. [Figure 15] A flowchart showing an algorithm according to an exemplary embodiment.

Best Mode for Carrying Out the Invention

[0019] (Detailed Description)[[ID= forty-two]] As used herein, the term "aerosol delivery device" is intended to encompass a system for delivering a substance to a user and includes the following: A non-combustible aerosol supply system that releases a compound from an aerosolizable material without burning the aerosolizable material, such as an electronic cigarette, a tobacco heating product, and a hybrid system that generates an aerosol using a combination of aerosolizable materials, and An article comprising an aerosolizable material and configured for use in one of these non-combustible aerosol supply systems.

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

[0021] According to this disclosure, a “non-combustible” aerosol delivery system is one in which the aerosolizable material constituting the aerosol delivery 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 delivery system, for example, a powered non-combustible aerosol delivery system.

[0022] In one embodiment, the non-combustible aerosol supply system is an e-cigarette, also known as 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 a requirement.

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

[0024] In one embodiment, the non-combustible aerosol supply 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 the form of a solid, liquid, or gel, and may or may not contain nicotine. In one embodiment, the hybrid system includes a liquid or gel aerosolizable material and a solid aerosolizable material. The solid aerosolizable material may include, for example, tobacco or a non-tobacco product.

[0025] Typically, a non-combustible aerosol supply system may include a non-combustible aerosol supply device and articles for use with the non-combustible aerosol supply system. However, it is also conceivable that an article itself, which includes means for supplying power to an aerosol generating component, may form a non-combustible aerosol supply system.

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

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

[0028] In one embodiment, the aerosol generating component is a heater capable of interacting with an aerosolizable material to form an aerosol by releasing one or more volatile substances from the aerosolizable material. In one embodiment, the aerosol generating component is capable of generating an aerosol from an aerosolizable material without heating. For example, the aerosol generating component may be capable of generating an aerosol from an aerosolizable material without applying heat, for example, by one or more of vibration, mechanical, pressurizing, or electrostatic means.

[0029] In one embodiment, the aerosolizable material may comprise an active material, an aerosol-forming material, and optionally one or more functional materials. The active material may comprise nicotine (optionally contained in tobacco or tobacco derivatives) or one or more other non-olfactory physiologically active materials. Non-olfactory physiologically active materials are materials included in the aerosolizable material to realize physiological reactions other than olfaction. The active substance used herein may be a physiologically active material that is intended to realize or enhance a physiological reaction. The active substance may be selected from, for example, nutritional supplements, nootropics, and psychotropic drugs. The active substance may be natural or synthetically obtained. The active substance may comprise, for example, nicotine, caffeine, taurine, theine, vitamins such as B6 or B12 or C, melatonin, cannabinoids, or components, derivatives, or combinations thereof. The active substance may comprise one or more components, derivatives, or extracts of tobacco, cannabis, or other plants. In some embodiments, the active substance comprises nicotine. In some embodiments, the active substance includes caffeine, melatonin, or vitamin B12.

[0030] The aerosol-forming material may contain one or more of the following: glycerin, glycerol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,3-butylene glycol, erythritol, meso-erythritol, ethyl vanillate, ethyl laurate, diethyl suberate, triethyl citrate, triacetin, diacetin mixture, benzyl benzoate, benzyl phenylacetate, tributyline, lauryl acetate, lauric acid, myristic acid, and propylene carbonate.

[0031] One or more functional materials may include one or more of the following: fragrances, carriers, pH adjusters, stabilizers, and / or antioxidants.

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

[0033] Aerosolizable materials, sometimes referred to herein as aerosol-generating materials, are materials capable of generating aerosols when, for example, heated, irradiated, or otherwise energized. Aerosolizable materials may be in the form of solids, liquids, or gels, which may or may not contain nicotine and / or flavorings. In some embodiments, aerosolizable materials may include amorphous solids, which may alternatively be referred to as monolithic solids (i.e., non-fibrous). In some embodiments, amorphous solids may be dry gels. Amorphous solids are solid materials capable of holding some fluid, such as a liquid, internally.

[0034] The aerosolizable material may be present on a substrate. The substrate may be, for example, paper, cardboard, cardboard, recycled aerosolizable material, plastic material, ceramic material, composite material, glass, metal, or metal alloy, or may contain these materials.

[0035] Consumables are articles containing or consisting of aerosol-generating materials, some or all of which are intended to be consumed by the user during use. Consumables may also include one or more other components, such as an aerosol-generating material storage area, an aerosol-generating material transfer component, an aerosol-generating area, a housing, a wrapper, a mouthpiece, a filter, and / or an aerosol modifier. Consumables may also include an aerosol generator, such as a heater, which releases heat to generate an aerosol in the aerosol-generating material during use. The heater may include, for example, a flammable material, an electrically conductive material, or a susceptor.

[0036] Figure 1 is a block diagram of a system according to an exemplary embodiment, shown as a whole by reference numeral 10. The system 10 includes a power supply in the form of a direct current (DC) voltage source 11, a switching component 13, a resonant circuit 14, a susceptor component 16, and a control circuit 18. The switching component 13 and the resonant circuit 14 may be coupled to each other within an induction heating component 12 that can be used to heat the susceptor 16.

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

[0038] The switching component 13 may be capable of generating an alternating current from the DC voltage source 11 (under the control of the control circuit 18). The alternating current may flow through one or more inductive elements, which may cause heating of the susceptor component 16. The switching component may include multiple transistors. Examples of DC-AC converters include H-bridge circuits or inverter circuits, which will be discussed below.

[0039] A susceptor is a material that can be heated by the intrusion of a fluctuating magnetic field, such as an alternating magnetic field. The heating material may be a conductive material, in which case inductive heating of the heating material is induced when a fluctuating magnetic field intrudes into it. The heating material may also be a magnetic material, in which case magnetic hysteresis heating of the heating material is induced when a fluctuating magnetic field intrudes into it. The heating material may have both conductivity and magnetism, in which case the heating material can be heated by both heating mechanisms.

[0040] Induction heating is the process by which a conductive object is heated by allowing a fluctuating magnetic field to penetrate it. This process is described by Faraday's law of electromagnetic induction and Ohm's law. An induction heater may include an electromagnet and a device for passing a fluctuating current, such as an alternating current, through the electromagnet. When the electromagnet and the object to be heated are appropriately positioned relative to each other, and as a result the fluctuating magnetic field generated by the electromagnet penetrates the object, one or more eddy currents are generated within the object. Objects have resistance to the flow of electric current. Therefore, when such eddy currents are generated within an object, the object is heated because the eddy currents flow against the electrical resistance of the object. This process is called Joule heating, Ohm heating, or resistance heating. An object that can be induced heated is known as a susceptor.

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

[0043] When an object possesses both conductivity and magnetism, introducing a fluctuating magnetic field into the object can induce both Joule heating and magnetic hysteresis heating. Furthermore, using magnetic materials can enhance the magnetic field, thereby increasing Joule heating.

[0044] In each of the above processes, heat is generated within the object itself rather than through an external heat source via heat conduction. Therefore, by selecting appropriate object materials and shapes, as well as the appropriate magnitude and direction of the fluctuating magnetic field relative to the object, it is possible to achieve a rapid temperature rise and a more uniform heat distribution. Furthermore, in induction heating and magnetic hysteresis heating, there is no need to provide a physical connection between the source of the fluctuating magnetic field and the object, which may improve design flexibility and control of the heating profile, and may also reduce costs.

[0045] Figures 2 and 3 show a non-combustible aerosol supply device according to an exemplary embodiment, shown in its entirety by reference numeral 20. Figure 2 is a perspective view of the aerosol supply device 20A with an outer cover attached. The aerosol supply device 20A may include a replaceable article 21, which may be inserted into the aerosol supply device 20A to heat a susceptor (the susceptor may be included in the article 21, as will be discussed further below). The aerosol supply device 20A may further include an actuation switch 22 which may be used to turn the aerosol supply device 20A on or off.

[0046] Figure 3 shows the aerosol supply device 20B with its outer cover removed. The aerosol generating device 20B includes an article 21, an operating switch 22, a plurality of inductive elements 23a, 23b, and 23c, and one or more air tube extenders 24 and 25. The one or more air tube extenders 24 and 25 may be optional.

[0047] Multiple inductors 23a, 23b, and 23c may each form part of a resonant circuit, such as the resonant circuit 14. Inductor 23a may include a helical inductor coil. In one example, the helical inductor coil is made from Litz wire / cable wound in a spiral to provide a helical inductor coil. Many alternative inductor formations are possible, for example, the inductor is formed within a printed circuit board. Inductors 23b and 23c may be similar to inductor 23a. The use of the three inductors 23a, 23b, and 23c is not essential for all exemplary embodiments. Therefore, the aerosol generating device 20 may include one or more inductors.

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

[0049] Figure 4 shows an article for use with a non-combustible aerosol supply device according to an exemplary embodiment, shown in its entirety by reference numeral 30. Article 30 is an example of the interchangeable article 21 described above with reference to Figures 2 and 3.

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

[0051] In one embodiment, the wrapper 32 includes aluminum foil. The aluminum foil has been found to be particularly effective in promoting aerosol formation within the aerosol-generating material 33. In one example, the aluminum foil has a metal layer having a thickness of about 6 μm. The aluminum foil may have a paper backing. However, in alternative configurations, the aluminum foil can have other thicknesses, for example, between 4 μm and 16 μm. The aluminum foil does not have to have a paper backing, but may have a backing formed from another material, for example, to help provide the foil with adequate tensile strength, or may not have a backing material at all. Metal layers or foils other than aluminum can also be used. Furthermore, it is not essential that such a metal layer be provided as part of article 30; for example, such a metal layer may be provided as part of apparatus 20.

[0052] The aerosol-generating material 33, also referred to herein as the aerosol-generating substrate 33, comprises at least one aerosol-forming material. In this example, the aerosol-forming material is glycerol. In alternative examples, the aerosol-forming material may be any other material or combination thereof as described herein. Aerosol-forming materials have been found to improve the perceived performance of an article by helping to transfer compounds, such as fragrance compounds, from the aerosol-generating material to the consumer.

[0053] As shown in Figure 4, the mouthpiece 31 of article 30 includes an upstream end 31a adjacent to the aerosol-generating substrate 33 and a downstream end 31b away from the aerosol-generating substrate 33. The aerosol-generating substrate may include tobacco, but alternatives are also possible.

[0054] In this example, the mouthpiece 31 includes a material body 36 upstream of the hollow tubular element 34, which is adjacent to and in contact with the hollow tubular element 34. The material body 36 and the hollow tubular element 34 each define a substantially cylindrical overall outer shape and share a common longitudinal axis. The material body 36 is wrapped in a first plug wrap 37. The first plug wrap 37 may have a basis weight of less than 50 gsm, such as between approximately 20 gsm and 40 gsm.

[0055] In this example, the hollow tubular element 34 is the first hollow tubular element 34, and the mouthpiece includes a second hollow tubular element 38, also called a cooling element, upstream of the first hollow tubular element 34. In this example, the second hollow tubular element 38 is upstream of the material body 36, adjacent to it, and in contact with it. The material body 36 and the second hollow tubular element 38 each define a substantially cylindrical overall outer shape and share a common longitudinal axis. The second hollow tubular element 38 is formed from multiple layers of paper, which are wound in parallel and joined at the seams to form the tubular element 38. In this example, the first and second layers of paper are provided in a double tube, but in other embodiments, three, four or more layers of paper can be used to form a triple, quadruple, or more layered tube. Other structures can also be used, such as spirally wound layers of paper, cardboard tubes, tubes formed using a papier-mâché type process, or molded or extruded plastic tubes. The second hollow tubular element 38 may also be formed using rigid plug wrap and / or tip paper as the second plug wrap 39 and / or tip paper 35 described herein, which means that a separate tubular element is not required.

[0056] The second hollow tubular element 38 is located around and defines a void within the mouthpiece 31 that functions as a cooling segment. The void provides a chamber through which heated volatile components generated by the aerosol-generating material 33 can flow. The second hollow tubular element 38 is hollow and provides a chamber for aerosol accumulation, but is rigid enough to withstand axial compressive forces and bending moments that may occur during manufacturing and use of the article 21. The second hollow tubular element 38 provides physical displacement between the aerosol-generating material 33 and the material body 36. The physical displacement provided by the second hollow tubular element 38 provides a temperature gradient along the length of the second hollow tubular element 38.

[0057] Naturally, article 30 is provided for illustrative purposes only. Those skilled in the art will notice many alternative configurations of such articles that can be used in the systems described herein.

[0058] Figure 5 is a block diagram of a circuit according to an exemplary embodiment, shown in its entirety by reference numeral 50. The circuit 50 includes a first switch 51, a second switch 52, a third switch 53, a fourth switch 54, and a resonant circuit 56. The first to fourth switches 51 to 54 may be implemented using transistors, as will be discussed further below.

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

[0060] The first and second switches 51 and 52 form the first rim of the bridge circuit, and the third and fourth switches 53 and 54 form the second rim. More specifically, the first switch 51 controls the first power supply (V in Figure 5). DD A second switch 52 can selectively provide a connection between the first connection point and ground (labeled as such), a third switch 53 can selectively provide a connection between the first power supply and the second connection point, and a fourth switch 54 can selectively provide a connection between the second connection point and ground. A resonant circuit 56 is provided between the first and second connection points.

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

[0062] Figure 7 is a block diagram of a circuit according to an exemplary embodiment, shown as a whole by reference numeral 70. Circuit 70 is an implementation example of circuit 50 described above.

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

[0064] The resonant circuit 79 includes a capacitor 76 and an inductor 73 such that the resonant circuit 79 can be an LC resonant circuit. Circuit 70 further shows a susceptor equivalent circuit 72 (which implements the susceptor component 16). The susceptor equivalent circuit 72 includes resistors and inductors that demonstrate the electrical effects of an exemplary susceptor component 16. If a susceptor is present, the susceptor component 72 and the inductor 73 may function as a transformer 71. The transformer 71 may generate a fluctuating magnetic field such that the susceptor is heated when the circuit 70 receives power. During the heating operation in which the susceptor component 16 is heated by the inductor component, the switching component 74 is driven (for example by the control circuit 18) so that an alternating current flows through the resonant circuit 79, with the first and second branches coupled in sequence. The resonant circuit 79 has a resonant frequency partially based on the susceptor component 16, and the control circuit 18 may be configured to control the switching component 74 to switch at or near the resonant frequency. Driving the switching circuit at or near the resonant point helps to improve efficiency and reduces energy lost to the switching element (which causes unnecessary heating of the switching element). In one example where an article 21 containing aluminum foil is heated, the switching component 84 may be driven at a frequency of around 2.5 MHz. However, in other implementations, the frequency may be anywhere between, for example, 500 kHz and 4 MHz.

[0065] Figure 8 is a block diagram of an exemplary embodiment of the system, shown in its entirety by reference numeral 80.

[0066] System 80 includes a pulse generation circuit 82, a resonant circuit 84 (e.g., resonant circuit 56), 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.

[0067] The pulse generation circuit 82 may be implemented using the switching configurations of systems 50 and 70 described above to generate pulses (e.g., pulse edges) by switching between positive and negative voltage sources.

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

[0069] The pulse response obtained by the pulse response processor 88 may contain noise. While numerous noise sources are possible, one source is the difference in switching timing of the pulse generation circuit 82. To reduce such noise, a low-pass filter function may be provided.

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

[0071] Figure 9 is a block diagram of a circuit according to an exemplary embodiment, shown as a whole by reference numeral 90. Circuit 90 includes the capacitor 61 and inductor 62 of the resonant circuit 56 described above. An output connection point, roughly indicated by reference numeral 64, is provided between the inductor and capacitor of the resonant circuit. The output capacitor 92 is used to couple the output connection point 64 to the output circuit 94.

[0072] Figure 10 is a flowchart of an algorithm according to an exemplary embodiment, shown in its entirety by reference numeral 100. Algorithm 100 illustrates an example of the use of system 80.

[0073] Algorithm 100 begins with operation 102, in which a pulse edge (generated by the pulse generation circuit 82) is applied to the resonant circuit 84. Figure 11 is a plot showing an exemplary pulse 110 (including the 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 (for example, the non-combustible aerosol construct 20 described above with reference to Figures 2 and 3), the pulse generation circuit 82 may select one of the multiple resonant circuits, each resonant circuit including an inductive element and a capacitor for inductive heating of a susceptor, and the applied pulse causes a pulse response between the capacitor and the inductive element of the selected resonant circuit.

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

[0076] Figure 12 is a plot, shown whole by reference no. 120, illustrating an exemplary pulse response 122 that may be generated at the connection point 64 between the capacitor 61 and the inductor 62 of the resonant circuit 64 in response to a pulse 110. As shown in Figure 12, the 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 the resonant circuit 56. In one configuration, no heating of the susceptor is consequently caused; 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 generated by the output circuit 94. The second pulse response 124 may be a pulse provided to the pulse response processor 88.

[0078] Figure 13 is a block diagram of a circuit according to an exemplary embodiment, shown in its entirety by reference numeral 130. Circuit 130 is an example of implementation of the output circuit 94 described above.

[0079] This circuit includes an output capacitor 92 used to couple the output connection point 64 to the output circuit 94, as described above. Circuit 130 also includes a signal conditioning circuit 132 and a comparator 134. The signal conditioning circuit 132 includes a first rim containing a first resistor R1 and a second resistor R2, and a second rim containing a first diode D1 and a second diode D2 in parallel. The signal conditioning circuit may be used to implement a DC voltage regulation function.

[0080] The signal conditioning circuit 130 serves at least three purposes. The first is to provide protection from voltage spikes, which is achieved by stacked diodes and a resistor (not shown) between the midpoint of the diodes and the output. The second is to provide signal decoupling, which is the purpose of the output capacitor 92 mentioned above. The third is to set the offset voltage of the pulse response at the output connection point 64.

[0081] The output of the signal conditioning circuit 130 may be supplied to the comparator 134. The offset voltage set by the signal conditioning circuit may be configured to match that of the input to the comparator so that the comparator is triggered at the center 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 attenuation rate of the pulse response) provide information about the system to which the pulse is applied. Therefore, one or more characteristics of the system to which the pulse is applied can be determined using system 80. For example, one or more performance characteristics such as a fault condition, the characteristics of an inserted article 21, the presence or absence of such an article, whether the article 21 is genuine or not, and the operating temperature can be determined based on the output signal derived from the pulse response.

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

[0084] Figure 14 is a block diagram of a circuit according to an exemplary embodiment, shown in its entirety by reference numeral 140. Circuit 140 includes the third switch 53, the fourth switch 54, and the resonant circuit 56 of the circuit 50 described above. The first connection point (between the first switch 51 and the resonant circuit 56) is connected to ground. Therefore, the second switch 52 of circuit 50 is replaced by a permanent connection to ground.

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

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

[0087] Figure 15 is a flowchart of an algorithm according to an exemplary embodiment, shown in its entirety by reference no. 150.

[0088] Algorithm 150 begins with operation 152, where a selection is made between the measurement mode and the heating mode in the operation of the resonant circuit (e.g., the 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 when the measurement mode is selected, and in full-bridge mode when the heating mode is selected in operation.

[0090] As described above, the bridge circuit includes a first rim having a first connection point, a second rim 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 such that the first connection point is connected to ground so that the low-pass filtering configuration described above is effective (as in circuit 140 above). As discussed above, the first rim may include a second transistor connected between the first connection point and ground. Therefore, configuring the bridge circuit in half-bridge mode may include switching the second transistor (of the first rim) to conduct while alternately switching the third and fourth transistors (of the second rim).

[0092] More specifically, the first rim may have a first transistor connected between a first power supply and a first connection point (as in the circuit 50 described above) and a second transistor connected between the first connection point and ground, and the first and second transistors of the first rim (as well as the third and fourth transistors of the second rim) are switched to perform full-bridge mode, while in half-bridge mode only the transistors of the second rim are switched.

[0093] In operation 156, one or more pulses or pulse edges are applied to the resonant circuit using the configured bridge circuit. In the measurement mode of operation, one or more pulse edges are applied to induce a pulse response between the capacitor and inductive element of the resonant circuit, the pulse response having a resonant frequency (this resonant frequency may be the measured value). In the heating mode of operation, one or more pulses are applied 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 understanding and teaching the claimed features. These embodiments are provided only as representative examples of embodiments and are not exhaustive and / or exclusive. The advantages, embodiments, examples, functions, features, structures, and / or other aspects described herein should not be considered as limitations to the scope of the invention as defined by the claims, or to equivalents thereof, and it should be understood that other embodiments may be used and modified without departing from the scope of the claimed invention. Various embodiments of the invention may suitably include, consist of, or essentially consist of, other disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. Furthermore, this disclosure may also include other inventions that are not currently claimed but may be claimed in the future.

Claims

1. A step of selecting between a measurement mode and a heating mode in the operation of a resonant circuit, wherein the resonant circuit comprises an inductor and a capacitor connected in series between the first and second connection points of a bridge circuit, The steps include configuring the bridge circuit in half-bridge mode when the measurement mode is selected, and configuring the bridge circuit in full-bridge mode when the heating mode in operation is selected, The steps include applying one or more pulse edges to the resonant circuit in the measurement mode of the operation described above, The operation includes the step of applying one or more pulses to the inductive element for inductive heating of the susceptor in the heating mode of the operation, The bridge circuit comprises a first rim having the first connection point, a second rim having the 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. Each applied pulse edge induces a pulse response between the capacitor and the inductor of the resonant circuit, and the pulse response has a resonant frequency. method.

2. The method according to claim 1, wherein the step of configuring the bridge circuit in the half-bridge mode includes configuring the bridge circuit such that the first connection point is connected to ground.

3. The method according to claim 1 or 2, wherein the first rim comprises a second transistor connected between the first connection point and ground, and the step of configuring the bridge circuit in the half-bridge mode includes switching the second transistor to a conductive state.

4. The method according to any one of claims 1 to 3, wherein the first rim comprises a first transistor connected between the first power supply and the first connection point, and a second transistor connected between the first connection point and ground.

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