Electronic circuit for an aerosol generator of an aerosol delivery device

Abstract

The present invention provides an electronic circuit for an aerosol generator of an aerosol delivery device, the electronic circuit comprising: a driver device having an H-bridge configuration for supplying alternating current to an aerosol generator comprising one or more first inductive elements and one or more second inductive elements; and a switch element configured to switch the alternating current supplied by the driver device to either the one or more first inductive elements or the one or more second inductive elements.

Description

[Technical Field]

[0001] The present invention relates to an electronic circuit for an aerosol generator of an aerosol delivery device, an aerosol delivery device, an aerosol generation system, and a method for generating an aerosol. [Background technology]

[0002] Smoking articles, such as cigarettes and cigars, burn tobacco during use to produce tobacco smoke. As an alternative to these articles, attempts have been made to provide products that release compounds without combustion. Examples of such products include so-called "heat-and-burn" products or tobacco heating devices or products, which release compounds by heating a material without burning it. This material may be, for example, a tobacco product or other non-tobacco product, and may or may not contain nicotine.

[0003] An aerosol delivery device is known that comprises an aerosol generator, the aerosol generator comprising two induction coils.

[0004] It would be desirable to provide improved electronic circuitry for aerosol generators. Summary of the Invention

[0005] According to one aspect, there is provided an electronic circuit for an aerosol generator of an aerosol delivery device, the electronic circuit comprising: a driver device having an H-bridge configuration for supplying an alternating current to an aerosol generator comprising one or more first inductive elements and one or more second inductive elements; a switch element configured to switch the alternating current supplied by the driver device to either the one or more first inductive elements or the one or more second inductive elements; Equipped with.

[0006] According to various embodiments, an electronic circuit for an aerosol generator or aerosol delivery device is provided. The electronic circuit includes a driver device having an H-bridge configuration to supply alternating current to an aerosol generator including one or more first inductive elements and one or more second inductive elements. These inductive elements may include, for example, coils or induction coils. The H-bridge configuration is a specific configuration designed to switch the polarity of a voltage applied to a load. In the context of an aerosol delivery device, the H-bridge configuration is a configuration in which a DC voltage from a DC battery is applied to the terminals of the inductive elements such that the direction of DC current flow is repeatedly reversed. As a result, an AC current is applied to the terminals of the inductive elements. The electronic circuit further includes a switch element, such as a MOSFET, configured to switch the AC current supplied by the driver device to either one or more first inductive elements or one or more second inductive elements. Such an electronic circuit allows two or more inductive elements located in different sections or zones of the aerosol generator to be driven by a single driver device. It will be appreciated that conventionally, an aerosol generator with two inductive elements would require two separate driver devices, one for each inductive element.

[0007] According to various embodiments, using a single H-bridge driver device to drive multiple inductive elements results in a simpler electronic circuit. It will be appreciated that a driver device with a full H-bridge configuration requires many separate electronic components (e.g., MOSFETs), which require a relatively large surface area on a printed circuit board (PCB). As a result, a conventional electronic circuit including two full H-bridge drivers to supply AC current to two inductive elements requires a relatively large PCB. However, it will also be appreciated that it is desirable to provide a compact aerosol delivery device. Therefore, an electronic circuit including a single full H-bridge driver device to drive two or more inductive elements saves space and allows the use of a PCB with a smaller footprint. As a result, a more compact aerosol delivery device can be provided. Furthermore, an additional advantage of using a single driver according to various embodiments to supply AC current to multiple inductive elements is that the energy requirements of the electronic circuit can be lower, thereby extending the battery life of the aerosol delivery device.

[0008] It will therefore be appreciated that an electronic circuit comprising, for example, a single full H-bridge driver to supply alternating current to multiple inductive elements, in combination with a switching element, is particularly beneficial in that it allows for a smaller footprint PCB to be used with lower energy requirements, thereby providing a more compact aerosol delivery device, and also allows for more sessions to be performed before the battery of the aerosol delivery device needs to be recharged.

[0009] Optionally, the switch element comprises a MOSFET.

[0010] According to another aspect, there is provided an aerosol delivery device comprising the electronic circuit described above.

[0011] Optionally, the aerosol delivery device further comprises an aerosol generator.

[0012] Optionally, the aerosol generator comprises one or more first directing elements and one or more second directing elements.

[0013] Optionally, the one or more first inductive elements comprise one or more inductive coils.

[0014] Optionally, the one or more second inductive elements comprise one or more inductive coils.

[0015] According to another aspect, the aerosol delivery device described above; an aerosol-producing article comprising an aerosol-forming material; An aerosol generating system is provided, comprising:

[0016] According to another aspect, providing an aerosol delivery device as described above; inserting an aerosol product article comprising an aerosol-forming material into an aerosol delivery device; energizing the aerosol-producing article; An aerosol generating method is provided, comprising: [Brief explanation of the drawings]

[0017] Various embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0018] [Figure 1] FIG. 1 shows the electronic circuitry of an aerosol delivery device having two induction coils for illustrative purposes, and shows an aerosol product placed within the heating chamber of the aerosol delivery device, where each induction coil is driven by a separate driver device. [Figure 2]FIG. 1 illustrates, for illustrative purposes, a portion of the electronic circuitry of an aerosol delivery device in which two induction coils are each driven by a separate H-bridge drive circuit. [Figure 3] 1 illustrates a driver device according to various embodiments, wherein the driver device is configured to provide alternating current to an aerosol generator comprising one or more first inductive elements and one or more second inductive elements, and a switch element switches the alternating current provided by the driver device to either one or more of the first inductive elements or one or more of the second inductive elements, such that a single driver device is configured to provide alternating current to multiple inductive elements. DETAILED DESCRIPTION OF THE INVENTION

[0019] Induction heating is a process of heating an electrically conductive object (or susceptor) by electromagnetic induction. An induction heater can include an inductive element, such as one or more coils or an electromagnet (the coil may be part of the electromagnet), and a circuit for passing a varying current, e.g., an alternating current, through the one or more coils. The varying current in the coil generates a varying magnetic field. This magnetic field penetrates a susceptor appropriately positioned relative to the one or more coils, generating eddy currents within the susceptor. Because the susceptor has an electrical resistance to eddy currents, the flow of eddy currents across this resistance causes the susceptor to heat by Joule heating. If the susceptor contains a ferromagnetic material, such as iron, nickel, or cobalt, heat can also be generated by magnetic hysteresis losses in the susceptor. That is, heat can also be generated by magnetic dipoles in the magnetic material changing their orientation as a result of aligning with the varying magnetic field. Compared to heating by conduction, induction heating allows for rapid heating because heat is generated within the susceptor. Furthermore, since no physical contact is required between the induction heater and the susceptor, there is a high degree of freedom in construction and application.

[0020] An induction heater can be considered to comprise an RLC circuit in which resistance (R) provided by a resistor, inductance (L) provided by an inductive element (e.g., one or more coils or an electromagnet configured to inductively heat a susceptor), and capacitance (C) provided by a capacitor are connected in series. In some cases, the resistance is provided by ohmic resistance in the portion of the circuit connecting the inductor and capacitor, so the RLC circuit does not necessarily include a resistor itself. Such a circuit can be referred to, for example, as an LC circuit. Such a circuit can exhibit electrical resonance. Electrical resonance occurs at a particular resonant frequency when the imaginary parts of the impedances or admittances of two or more circuit elements have the same absolute value and opposite signs and therefore cancel each other out.

[0021] In an RLC or LC circuit, resonance occurs when the collapsing magnetic field of an inductor generates a current that charges a capacitor in its winding. The capacitor then discharges, providing the current that creates the magnetic field in the inductor. While the capacitor is charging, energy is stored in the electric field, and while current flows through the inductor, energy is stored in the magnetic field. Energy can be transferred from one side of the circuit to the other, which can be oscillatory in nature. When the circuit is driven at the resonant frequency, the series impedance of the inductor and capacitor is minimized and the circuit current is maximized. Therefore, driving an RLC or LC circuit at or near the resonant frequency can provide effective and / or efficient induction heating.

[0022] As will be appreciated by those skilled in the art, a transistor is a semiconductor device for switching electronic signals. A transistor typically has at least three terminals for connecting to an electronic circuit. A field effect transistor (FET) is a specific type of transistor that can vary the effective conductance of the transistor using the effect of an applied electric field.

[0023] A field effect transistor may comprise a body B, a source terminal S, a drain terminal D, and a gate terminal G. A field effect transistor comprises an active channel comprising a semiconductor through which charge carriers (e.g., electrons or holes) flow between the source S and the drain D. The conductivity of the channel, i.e., the conductivity between the drain D and source S terminals, is a function of the potential difference between the gate G and source S terminals (which may be generated, for example, by a potential applied to the gate terminal G).

[0024] One type of field effect transistor is the enhancement-mode FET, and it will be appreciated that in an enhancement-mode FET, when the voltage between the gate G and the source S is substantially zero, the FET is in an off state (i.e., a state that substantially prevents current from passing through), and when the voltage between the gate G and the source S is not substantially zero, the enhancement-mode FET switches to an on state (i.e., a state that substantially allows current to pass through).

[0025] An n-channel (or n-type) field-effect transistor (n-FET) is a field-effect transistor whose channel comprises an n-type semiconductor, where electrons are the majority carriers and holes are the minority carriers. For example, an n-type semiconductor can comprise an intrinsic semiconductor (e.g., silicon) doped with a donor impurity (e.g., phosphorus). In an n-channel FET, the drain terminal D is placed at a higher potential than the source terminal S (i.e., there is a positive drain-to-source voltage, or, in other words, there is a negative source-to-drain voltage). To turn on the n-channel FET (i.e., to allow current to flow), a switching potential higher than the potential of the source terminal S is applied to the gate terminal G.

[0026] A p-channel (or p-type) field-effect transistor (p-FET) is a field-effect transistor whose channel comprises a p-type semiconductor, where holes are the majority carriers and electrons are the minority carriers. For example, a p-type semiconductor can comprise an intrinsic semiconductor (e.g., silicon) doped with an acceptor impurity (e.g., boron). In a p-channel FET, the source terminal S is placed at a higher potential than the drain terminal D (i.e., there is a negative drain-to-source voltage, or in other words, there is a positive source-to-drain voltage). To turn on the p-channel FET (i.e., to allow current to flow), a switching potential lower than the potential of the source terminal S (and which may, for example, be higher than the potential of the drain terminal D) is applied to the gate terminal G.

[0027] A metal-oxide-semiconductor field-effect transistor (MOSFET) is a field-effect transistor in which the gate terminal G is electrically isolated from the semiconductor channel by an insulating layer. In some examples, the gate terminal G is a metal and the insulating layer is an oxide (e.g., silicon dioxide), hence the "metal-oxide-semiconductor." However, in other examples, the gate may be made of a material other than a metal (e.g., polysilicon) and the insulating layer may be made of a material other than an oxide (e.g., other dielectric materials). Nevertheless, such devices are typically referred to as metal-oxide-semiconductor field-effect transistors (MOSFETs), and the terms metal-oxide-semiconductor field-effect transistor or MOSFET as used herein should be understood to include such devices.

[0028] One type of MOSFET is the n-channel (or n-type) MOSFET, where the semiconductor is n-type. N-channel MOSFETs (n-MOSFETs) can be operated in the same manner as described above in connection with the n-channel FET. Another type of MOSFET is the p-channel (or p-type) MOSFET, where the semiconductor is p-type. P-channel MOSFETs (p-MOSFETs) can be operated in the same manner as described above in connection with the p-channel FET.

[0029] An n-MOSFET typically has a lower source-drain resistance than a p-MOSFET. It will be appreciated that an n-MOSFET generates less heat when it is in the on state (i.e., a state in which current flows) compared to a p-MOSFET. Therefore, an n-MOSFET wastes less energy during operation compared to a p-MOSFET. Furthermore, an n-MOSFET typically has a shorter switching time (i.e., the characteristic response time between changing the switching potential applied to the gate terminal G and the MOSFET changing whether or not current flows) compared to a p-MOSFET. This allows for higher switching speeds and improved switching control.

[0030] As described in detail below, an H-bridge is an electronic circuit that switches the polarity of a voltage applied to a load. In the context of an aerosol delivery device, an H-bridge circuit can be used to rapidly switch the direction of current flow through an inductor coil. It will be appreciated that the use of MOSFETs as high-speed switches allows the direction of current through the induction coil to be rapidly switched. As a result, applying a DC voltage to an H-bridge circuit including multiple MOSFETs can provide an electronic circuit that allows AC current to flow through the induction coil. According to various embodiments, the frequency of the AC current can be approximately 2 MHz.

[0031] As will be described in more detail below, the MOSFETs used in the H-bridge to supply AC current to the induction coil may, according to various embodiments, include enhancement-mode n-channel MOSFETs.

[0032] FIG. 1 is a schematic diagram of the electronic circuitry 106 of the aerosol delivery device 100. The aerosol delivery device 100 includes an aerosol generator that includes two induction heating elements 108, 109 and control electronics for energizing the heating elements 108, 109. The aerosol delivery device 100 may include a single induction heating element, or, as shown in FIG. 1, the aerosol delivery device 100 may include a first induction heating element 108 and a second induction heating element 109. The first induction heating element 108 may be configured to heat the first susceptor 110a during use, and the second induction heating element may be configured to heat the second susceptor 110b during use. Alternatively, the first and second induction heating elements may be configured to heat different portions of the same susceptor during use.

[0033] An aerosol product article 116 is shown inserted into the aerosol delivery device 100, and it is understood that the aerosol product article 116 includes an aerosol-forming material that, in use, is heated by the first and second susceptors 110 a, 110 b. It is understood that the first and second susceptors 110 a, 110 b are heated by inducing an electric current therein. The first and second susceptors 110 a, 110 b may include ferromagnetic portions, which may include metals such as iron, nickel, or cobalt. When an alternating current is applied to either or both of the first and second inductive elements 108, 109, the alternating current heats the corresponding first and / or second susceptors 110 a, 110 b by Joule heating and / or magnetic hysteresis heating. It is therefore understood that the electronic circuit 106 is configured to pass an alternating current through the first and second inductive elements 108, 109 and induce a corresponding current in the first and second susceptors 110a, 110b, causing the susceptors 110a, 110b to heat up, thereby heating the aerosol-generating material (provided as part of the aerosol product item 116).

[0034] A DC power supply 104 is provided, forming part of an electronic circuit 106. The DC power supply 104 may comprise a battery or a battery pack. The DC power supply 104 is configured to supply DC power to the electronic circuit 106. The electronic circuit 106 is electrically connected to first and second inductive elements 108, 109. Each inductive element 108, 109 may comprise, for example, an electromagnet including one or more coils or solenoids. The first and second inductive elements 108, 109 may be formed from copper wire. The electronic circuit 106 is configured to convert the DC current provided by the DC power supply 104 into AC current and supply it to the first and second inductive elements 108, 109. The electronic circuit 106 is configured to drive the first and second inductive elements 108, 109 at a relatively high frequency, for example, approximately 2 MHz.

[0035] The first and second susceptors 110 a, 110 b are positioned relative to the first and second induction heating elements 108, 109 to transfer inductive energy from the first and second induction heating elements 108, 109 to the first and second susceptors 110 a, 110 b. When an alternating current is applied to either or both of the first and second induction elements 108, 109, the alternating current heats the corresponding first and / or second susceptor 110 a, 110 b by Joule heating and / or magnetic hysteresis heating. The first and / or second susceptors 110 a, 110 b are positioned to heat an aerosol-forming material provided as part of the aerosol product article 116, for example, by conduction, convection, and / or radiation heating, to generate an aerosol during use.

[0036] The first and / or second susceptors 110a, 110b may form part of the aerosol delivery device 100. Alternatively, the first and / or second susceptors 110a, 110b and the aerosol-generating material may be configured to form an integrated unit or consumable that may be inserted into and / or removed from the aerosol delivery device 100, and the integrated unit or consumable may be disposable. In some examples, the first and second inductive elements 108, 109 may be removable from the aerosol delivery device 100, for example, for replacement. The aerosol delivery device 100 may be handheld. The aerosol delivery device 100 may be configured to heat the aerosol-generating material to generate an aerosol for a user to inhale.

[0037] It should be noted that the term "aerosol-forming material" as used herein includes materials that provide volatile components upon heating. These volatile components are typically provided in the form of a vapor or aerosol. The aerosol-forming material may be a non-tobacco-containing material or a tobacco-containing material. For example, the aerosol-forming material may be or contain tobacco. The aerosol-forming material may include, for example, one or more of whole tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco, tobacco extract, homogenized tobacco, or tobacco substitutes. The aerosol-forming material may be in the form of shredded tobacco, cut rag tobacco, extruded tobacco, reconstituted tobacco, reconstituted material, liquid, gel, gelled sheet, powder, or aggregate. The aerosol-forming material may also include other non-tobacco products. These non-tobacco products may or may not contain nicotine, depending on the product. The aerosol-forming material may also include one or more humectants, such as glycerol or propylene glycol.

[0038] Aerosol delivery device 100 may include a housing (not shown) configured to house DC battery 104, electronic circuitry 106, and first and second inductive elements 108, 109, and optionally first and second susceptors 110 a, 110 b. The housing may include a mouthpiece to allow generated aerosol to exit aerosol delivery device 100 during use.

[0039] In use, a user may activate the electronic circuitry 106, for example, by activating a button or via a puff detector (not shown), to apply alternating current to the first and second inductive elements 108, 109, thereby inductively heating the first and second susceptors 110a, 110b, which in turn heats the aerosol-generating material and generates an aerosol. The aerosol may be generated and mixed with air drawn in through an air inlet (not shown) of the aerosol delivery device 100. The aerosol and air mixture may then be directed toward the mouthpiece, from which the aerosol exits the aerosol delivery device 100 and may be inhaled by the user.

[0040] The aerosol-delivery device 100, which includes the electronic circuitry 106 and further includes first and second inductor elements 108, 109 coupled to the first and second susceptors 110a, 110b, may be configured to heat the aerosol-generating material to a temperature range to volatilize at least one component of the aerosol-generating material without burning the aerosol-generating material. For example, according to various embodiments, the aerosol-generating material may be heated to a temperature in the range of 50-100°C, 100-150°C, 150-200°C, 200-250°C, 250-300°C, or greater than 300°C.

[0041] The DC power supply 104 (which may include a battery pack) may be connected to a driver device 124 for supplying electrical energy to the first and second inductive elements 108, 109 (which may include two coils). The driver device 124 may be connected to a positive terminal 126 of the battery pack 104, which provides a relatively high potential, and a negative terminal 128 of the battery pack 104, which provides a relatively low, zero, or negative potential, or ground GND. Thus, a voltage is developed across the driver device 124.

[0042] For illustrative purposes, the driver device 124 includes a first full H-bridge driver circuit 142, 144 coupled to two dual MOSFETs 130, 132 for supplying alternating current to the first inductive element 108. The two dual MOSFETs 130, 132 may each include an enhancement mode n-channel MOSFET.

[0043] The driver device 124 further includes a second full H-bridge driver circuit 146, 148 coupled to two additional dual MOSFETs 134, 136 for supplying AC current to the second inductive element 109. The two additional dual MOSFETs 134, 136 may each comprise an enhancement mode n-channel MOSFET. Thus, the entire driver device may include eight MOSFETs 130, 132, 134, 136, which may comprise enhancement mode n-channel MOSFETs.

[0044] It will therefore be understood that the configuration shown in FIG. 1 is provided solely to illustrate how two inductive elements may be driven by separate full H-bridge driver circuits 130, 132, 134, 136, respectively.

[0045] However, as explained in more detail below with reference to Figure 3, various embodiments described herein provide an electronic circuit that modifies the configuration shown in Figure 1 to provide a single full H-bridge driver circuit in combination with one switching element. As a result, according to various embodiments, one of the two full H-bridge driver circuits 130, 132, 134, 136 shown in Figure 1 is redundant; instead, only one of the two full H-bridges 130, 132, 134, 136 shown in Figure 1 may be provided in combination with one switching element (not shown in Figure 1).

[0046] 2, for purposes of illustration, the disclosed electronic circuit 106 is shown to include a first full H-bridge including a pair of MOSFETs 130 connected to a first terminal of a first inductive element 108 (which is driven by a first H-bridge driver circuit 142) and a pair of MOSFETs 132 connected to a second terminal of the first inductive element 108 (which is driven by a second H-bridge driver circuit 144). The first inductive element 108 may include a first inductive coil 120.

[0047] A second full H-bridge is provided, which includes two MOSFETs 134 connected to a first terminal of the second inductive element 109 (which are driven by a third H-bridge driver circuit 146) and two MOSFETs 136 connected to a second terminal of the second inductive element 109 (which are driven by a fourth H-bridge driver circuit 148). The second inductive element 109 may include a second inductive coil 122.

[0048] In view of the above with respect to FIG. 1, it should be understood that FIG. 2 is disclosed by way of example to illustrate how a full H-bridge driver circuit can be connected to the terminals of an inductive element to supply alternating current to the element.

[0049] As will be appreciated, according to various embodiments, a single H-bridge driver circuit is provided in combination with the switching elements. It will be apparent that this approach of using a single H-bridge driver element in combination with the switching elements, according to various embodiments, reduces the PCB footprint compared to a PCB that may be used to implement the electronic circuit shown in FIG.

[0050] For illustrative purposes, it will be understood that each pair of MOSFETs 130, 132, 134, 136 shown in Figure 2 may be connected to a high potential VBAT or VBAT POWER+ and a negative potential POWER- or GND (shown in Figure 1 but omitted in Figure 2) of the battery pack 104. Referring to Figure 1, a resistor 140 (e.g., 2 mΩ) may be provided in the connection line between the battery pack 104 and the pair of MOSFETs 130, 132, 134, 136.

[0051] 1 may include a first H-bridge driver circuit 142, a second H-bridge driver circuit 144, a third H-bridge driver circuit 146, and a fourth H-bridge driver circuit 148. The driver circuits 142, 144, 146, 148 are configured to drive each of the pairs of switching elements or MOSFETs 130, 132, 134, 136, i.e., to control each pair of MOSFETs 130, 132, 134, 136 to either a conducting or non-conducting state in order to redirect current between the terminals of the inductive elements 108, 109.

[0052] As shown in detail in Figure 2, the four driver circuits 142, 144, 146, 148 may be provided with a bias or supply voltage of, for example, 5V. The required value may vary depending on the particular driver. This supply voltage may be derived from a high potential VBAT POWER+ (Figure 1) or VBAT (Figure 2) from the battery pack 104, or may be derived via a buck-boost regulator or DC-DC converter 150 or other suitable regulator.

[0053] Aerosol delivery device 100 may be operated in a first, normal or standard mode of operation, and a second, or boost mode of operation. When aerosol delivery device 100 is operated in the second, or boost mode of operation, it may be desirable to increase the temperature of one or both of susceptors 110a, 110b, for example, to increase the temperature profile. In the second, or boost mode of operation, a DC voltage of 5 V may be supplied to driver circuits 142, 144, 146, 148.

[0054] In a first mode of operation, drivers 142, 144, 146, 148 may be supplied with a low voltage, for example 3.3V. This supply voltage may be derived from a buck-boost regulator or 5V from a DC-DC converter 150 via a voltage regulator 152. Voltage regulator 152 may comprise a low dropout (LDO) regulator.

[0055] The driver device 124 is thus configured to supply AC current from input DC current from the battery pack 104 to the coils 120, 122 or their corresponding LC circuits for driving the first and second inductive elements 108, 109 or the coils 120, 122 in use.

[0056] 1 , a central controller 154, such as a microcontroller unit (MCU), may be provided. The central controller 154 acts as a controller for the driver circuits 142, 144, 146, and 148. That is, the central controller 154 may be configured to control the circuits 142, 144, 146, and 148, for example, by providing pulse width modulated (PWM) signals to the driver circuits 142, 144, 146, and 148, which in turn control the dual MOSFETs 130, 132, 134, and 136.

[0057] The central controller 154 may be configured to set the frequency at which the dual MOSFETs 130, 132, 134, 136 are switched between conductive and non-conductive states, such that the central controller 154 is effectively configured to set the frequency of the alternating current applied to the inductive elements 108, 109.

[0058] According to various embodiments, the central controller 154 may be configured to determine a resonant frequency f of the inductive elements 108, 109. Additionally, the central controller 154 may be configured to supply an alternating current to the inductive elements 108, 109 at a first frequency f, for example, within 10% of the resonant frequency f. The central controller 154 may also be configured to supply an alternating current to the inductive elements 108, 109 at a second frequency f, for example, at least 10% below the resonant frequency f or at least 10% above the resonant frequency f.

[0059] The central controller 154 may also control various other functions and elements of the electronic circuit 106. For example, the central controller 154 may control the buck-boost regulator or DC-DC converter 150 and the voltage regulator 152 to supply either 5V (boost mode) or 3.3V (normal mode) to the driver circuits 142, 144, 146, 148.

[0060] 1, electronic circuit 106 may include battery charging circuit 156, which is connected to battery pack 104 at positive terminal 126 and may also be connected to ground GND. Battery charging circuit 156 may be connected to an interface 158, such as a USB interface, via, for example, positive connection line 160 for a high potential and a corresponding negative connection line 161. This allows, for example, a power plug to be connected to aerosol delivery device 100 to charge or recharge battery pack 104.

[0061] A USB temperature sensor 162, such as a negative temperature coefficient (NTC) temperature sensor, may be located on interface 158 and connected to central controller 154. USB temperature sensor 162 monitors the temperature of interface 158 and allows for controlled charging of battery 104. For example, charging may be interrupted if the temperature of interface 158 is determined to be above a maximum desired temperature threshold.

[0062] A data connection line 164 (e.g., a universal synchronous / asynchronous receiver-transmitter (USART) or other type of connection) may be provided between interface 158 and central controller 154, allowing data exchange between central controller 154 and an external device connected to aerosol delivery device 100 via interface 158, e.g., for controlling charging. Both data transfer directions are indicated in FIG. 1 by two arrowed lines: one from central controller 154 to interface 158 and one from interface 158 to central controller 154.

[0063] A debug connection line 166 (e.g., a serial wire debug (SWD) or other type of connection line) may be provided between interface 158 and central controller 154. Debug connection line 166 allows debugging of central controller 154 via an external device connected to aerosol delivery device 100 via interface 158. Both data transfer directions are indicated by two arrowed lines: one from central controller 154 to interface 158 and one from interface 158 to central controller 154.

[0064] The battery charging circuit 156 may be configured to supply power to the central controller 154 via power line 168. For example, the central controller 154 may be supplied with a voltage of 2.5 V. Any suitable type of voltage regulator 170 may be used to generate the required supply voltage for the central controller 154.

[0065] According to various embodiments, a battery temperature sensor 172 (e.g., an NTC temperature sensor) may be provided in the battery pack 104 and connected to the central controller 154. The battery temperature sensor 172 allows the temperature of the battery pack 104 to be monitored and charging of the battery pack 104 to be controlled. For example, charging may be interrupted if the battery pack 104 is determined to be excessively hot. Furthermore, normal operation of the aerosol delivery device 100 may be controlled based on the temperature of the battery pack 104.

[0066] Temperature sensors 174 (e.g., NTC temperature sensors) may be provided proximate the first and second inductive elements 108, 109 or the corresponding coils 120, 122 and connected to the central controller 154. According to various embodiments, thermocouple temperature sensors 176 may also be provided. In particular, each coil 120, 122 may be monitored by a separate thermocouple 176, and one or both thermocouples 176 may be connected to the central controller 154. A reference voltage Ref may be supplied to a first comparator 178 coupled to the temperature sensor 174. Similarly, the reference voltage Ref may be supplied to a second comparator 180 coupled to the thermocouple 180. These comparators 178, 180 may be provided to achieve a measurable voltage, thereby enabling monitoring of the temperature of the coils 120, 122 or the corresponding inductive elements 108, 109 and controlling their operation. For example, the operating frequency of the alternating current applied to the inductive elements 108, 109 can be altered, varied, increased, or decreased in response to the measured temperature of the inductive elements 108, 109 or coils 120, 122. For example, as will be appreciated by those skilled in the art, the resonant frequency f of the coils 120, 122 or inductive elements 108, 109 can change with temperature. For example, as the temperature of the inductive elements 108, 109 increases over time, the resonant frequency f of the inductive elements 108, 109 or coils 120, 122 can decrease over time.

[0067] The central controller 154 may be configured to measure the current supplied to the inductive elements 108, 109 or the coils 120, 122 by dual MOSFETs (switches) 130, 132, 134, 136. For example, a current sensing unit I_SENSE may be provided in a line connected between the MOSFETs 130, 132, 134, 136 and / or the H-bridge driver circuits 142, 144, 146, 148 and the negative terminal 128 of the resistor 140. An analog-to-digital converter (ADC) 182 may be used to convert the measured current into a digital voltage level and provide it to the central controller 154.

[0068] Indicator lights 184 (e.g., LEDs) may be provided to indicate one of several operational states of aerosol delivery device 100. LEDs 184 may comprise RGB LEDs, i.e., LEDs capable of providing illumination across the entire visible light spectrum or only a portion thereof. For example, LEDs 184 may be illuminated to display red, green, blue, white, and a variety of different shades. Indicator lights 184 may be powered via voltage regulator 152 and may be controlled by central controller 154. Indicator lights 184 may be provided as part of a user interface located on an exterior portion of aerosol delivery device 100.

[0069] Button or key 186 may be provided, for example, on the exterior housing of aerosol delivery device 100. Button or key 186 may be used to change the operating mode of aerosol delivery device 100, to turn power on or off, etc. Button or key 186 may be connected to central controller 154, which may receive a signal provided by operating button or key 186 and may, for example, perform a required operational change.

[0070] A haptic motor 188 or any other haptic feedback element may be provided. The haptic motor 188 may be powered by the battery pack 104 and controlled by the central controller 154, thereby allowing a user of the aerosol delivery device 100 to receive haptic feedback during use.

[0071] The central control unit 154 or its driver controller portion may be configured to control, via the driver unit 124, the frequency of the alternating current supplied to the coils 120, 122 or the LC circuits comprising these coils, and thus control the frequency of the alternating current flowing through the inductive elements 108, 109 or the coils 120, 122. The inductive elements 108, 109 or the corresponding coils 120, 122 may be operated in various modes of operation in which only one or both of the inductive elements 108, 109 are energized at any particular time.

[0072] As discussed above, the LC circuit may exhibit resonance. The central controller 154 or its driver controller portion may control the frequency of the AC current (i.e., the drive frequency) flowing through the coils or LC circuit to be at or near the resonant frequency of one or both of the coils 120, 122 or the LC circuit. For example, the drive frequency may be in the MHz range, e.g., 0.5 to 1.5 MHz (e.g., 1 MHz). In other embodiments, the drive frequency may be in the 1 to 2 MHz range. It will be understood that other frequencies may be used depending on the particular coils or LC circuits (and / or their components) and / or susceptors 110a, 110b used. For example, it will be understood that the resonant frequency f0 of the LC circuit depends on the inductance L of the coils 120, 122 and the capacitance C of the circuit, and thus may depend on the inductive elements 108, 109, the capacitor, and the susceptors 110a, 110b.

[0073] In use, when the central control unit 154 or its driver controller portion is activated, for example by a user, the central control unit 154 or its driver controller portion may control the driver unit 124 to pass an alternating current through one or more of the coils 120, 122 or the LC circuit, and thus through the inductive elements 108, 109, thereby causing inductive heating of the susceptors 110a, 110b. As the susceptors 110a, 110b heat, they may heat the aerosol-generating material that forms part of the aerosol product article 116, so that an aerosol may be generated for inhalation by the user.

[0074] Referring to FIG. 2, a portion of the electronic circuit 106 of the aerosol delivery device 100 of FIG. 1 is shown in more detail. As described with reference to FIG. 1, the driver apparatus may include an H-bridge configuration with two full H-bridges, one for each of the coils 120 and 122. Each full H-bridge includes four switching elements, which may include multiple transistors or pairs of MOSFETs 130, 132, 134, and 136. The four pairs of MOSFETs 130, 132, 134, and 136 may be implemented as two dual MOSFETs per full H-bridge. The dual MOSFETs 130, 132, 134, and 136 are shown in FIG. 2, with two pairs of MOSFETs 130, 132, 134, and 136 provided for each of the coils 120 and 122. Each pair of MOSFETs 130, 132, 134, 136 is connected to a high potential VBAT POWER+ or VBAT of the battery pack and a negative potential POWER- or GND (not shown here).

[0075] Thus, two half H-bridge drivers 142, 144; 146, 148 are provided for each full H-bridge or pair of dual MOSFETs 130, 132, 134, 136. The H-bridge drivers 142, 144; 146, 148 may be provided with a bias or supply voltage of, for example, 5V (e.g., in boost mode of operation) and a bias or supply voltage of, for example, 3.3V (e.g., in standard mode of operation), as described above.

[0076] 1, a central control unit such as the MCU 154 may function as a controller for the drivers 142, 144, 146, and 148; i.e., the MCU 154 may be configured to control the drivers 142, 144, 146, and 148 and provide clock signals to the drivers 142, 144, 146, and 148. For example, a first clock signal CLK1 may be provided to the first driver 142, and a second clock signal CLK2 may be provided to the second driver 144, where these drivers 142, 144 are configured to drive the pair of MOSFETs 130, 132 connected to the first coil 120. A third clock signal CLK3 may be provided to the third driver 146, and a fourth clock signal CLK4 may be provided to the fourth driver 148, where these drivers 146, 148 are configured to drive the pair of MOSFETs 134, 136 connected to the second coil 122.

[0077] 3 illustrates an electronic circuit 300 according to various embodiments. The electronic circuit 300 includes a driver device configured to supply alternating current to an aerosol generator including one or more first inductive elements 108 and one or more second inductive elements 109. The driver device includes a full H-bridge driver circuit. The full H-bridge driver circuit may include four MOSFETs. The MOSFETs used in the full H-bridge driver circuit may include enhancement-mode n-channel MOSFETs.

[0078] According to various embodiments, the output from the full H-bridge driver circuit is connected to a switch element that forms part of the electronic circuit 300. The switch element may be configured to switch the alternating current provided by the driver device to either one or more first inductive elements 108 or one or more second inductive elements 109. The switch element may comprise a MOSFET. For example, the switch element may comprise an enhancement mode n-channel MOSFET.

[0079] According to one mode of operation, during a use session, the switch element may be configured to initially energize one or more first inductive elements 108, and then, during that session, the switch element may be configured to energize one or more second inductive elements 109. As another example, according to another mode of operation, during a use session, the switch element may be configured to initially energize one or more second inductive elements 109, and then, during that session, the switch element may be configured to energize one or more first inductive elements 108.

[0080] According to other embodiments, during a use session, the switch element may be configured to repeatedly switch between applying alternating current to one or more first inductive elements 108 and applying alternating current to one or more second inductive elements 109. During a use session, the ratio of time spent energizing one or more first inductive elements 108 to time spent energizing one or more second inductive elements 109 may be equal, for example 50% / 50%. However, in other embodiments, the time spent energizing one or more first inductive elements 108 may be greater than the time spent energizing one or more second inductive elements 109, for example 60% / 50%, 70% / 30%, 80% / 20%, or 90% / 10%. Alternatively, in other embodiments, the time spent energizing one or more first inductive elements 108 may be less than the time spent energizing one or more second inductive elements 109, for example, 40% / 60%, 30% / 70%, 20% / 80%, or 10% / 90%.

[0081] It will be appreciated that, according to various embodiments, only a single full H-bridge driver circuit is required to supply AC current to both the one or more first inductive elements 108 and the one or more second inductive elements 109. The one or more first inductive elements 108 and the one or more second inductive elements 109 may comprise one or more inductive coils.

[0082] To address various problems and advance the art, this disclosure presents various embodiments by way of example. The advantages and features of this disclosure are merely those of representative embodiments and are not exhaustive and / or exclusive. They are presented solely for the purpose of understanding and teaching the claimed invention. The advantages, embodiments, examples, functions, features, structures, and / or other aspects of this disclosure should not be construed as limiting the disclosure as defined by the claims or to the equivalents of the claims; other embodiments may be utilized, and changes may be made without departing from the spirit of the claims. Various embodiments may suitably comprise, have, or essentially comprise various combinations of elements, components, features, portions, steps, means, etc., not specifically described herein, and thus it is understood that features of the dependent claims may be combined with features of the independent claims in combinations other than those explicitly recited in the claims. This disclosure may include other inventions not currently claimed but that may be claimed in the future.

Claims

1. 1. An electronic circuit for an aerosol generator of an aerosol delivery device, comprising: a driver device having an H-bridge configuration for supplying an alternating current to an aerosol generator comprising one or more first inductive elements and one or more second inductive elements; a switch element configured to switch an alternating current supplied by the driver device to either the one or more first inductive elements or the one or more second inductive elements; An electronic circuit comprising:

2. The electronic circuit of claim 1 , wherein the switch element comprises a MOSFET.

3. An aerosol delivery device comprising the electronic circuit of claim 1 or 2.

4. The aerosol delivery device of claim 3 , further comprising an aerosol generator.

5. 5. The aerosol delivery device of claim 4, wherein the aerosol generator comprises one or more first inductive elements and one or more second inductive elements.

6. The aerosol delivery device of claim 5 , wherein the one or more first inductive elements comprise one or more inductive coils.

7. 7. The aerosol delivery device of claim 5 or 6, wherein the one or more second inductive elements comprise one or more inductive coils.

8. An aerosol delivery device according to any one of claims 3 to 7; an aerosol-producing article comprising an aerosol-forming material; An aerosol generating system comprising:

9. 1. A method for generating an aerosol, comprising: Providing an aerosol delivery device according to any one of claims 3 to 7; inserting an aerosol product article comprising an aerosol-forming material into the aerosol delivery device; energizing the aerosol-producing article; A method for providing the above.

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