aerosol generator

Abstract

The present application provides an aerosol generating device including a cavity for receiving an aerosol-generating product, a battery cell including a first electrode and a second electrode, a first switch transistor and a second switch transistor, an LCC oscillator including an induction coil, a first capacitor and a second capacitor, wherein a first end of the first capacitor is connected to the first electrode, a second end of the first capacitor is connected to the first end of the second capacitor, a second end of the second capacitor is connected to the second electrode, and a first end of the induction coil is connected to the second end of the first capacitor, and a second end of the first switch transistor is connected to the first electrode via the first switch transistor and to the second electrode via the second switch transistor, and the first switch transistor and the second switch transistor are alternately turned on and off to cause an alternating current to flow through the induction coil to generate a varying magnetic field, and a susceptor configured to be penetrated by the varying magnetic field, generate heat, and heat the aerosol-generating product received in the cavity. The above aerosol generating device forms an inverse transformation using the LCC oscillator, resulting in a lower resonant frequency and higher efficiency than an LC oscillator.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from a Chinese patent for an invention entitled "Aerosol Generating Device" filed with the China Patent Office on December 8, 2020, application number 202022975947.8, the entire contents of which are incorporated herein by reference.

[0002] The embodiments of the present application relate to the field of electromagnetic induction heated non-combustion smoking devices, and in particular to aerosol generating devices. [Background technology]

[0003] Tobacco products (e.g., cigarettes, cigars, etc.) burn tobacco to produce tobacco smoke during use. As an alternative to these combustible tobacco products, efforts have been made to produce products that release compounds without combustion.

[0004] One example of such a product is a heating device, which releases compounds by heating a material rather than burning it. For example, the material can be tobacco or other non-tobacco products, which may or may not contain nicotine. In known devices, a heater that generates heat through electromagnetic induction heats the tobacco product to generate a smoking aerosol. In one prior art example of the heating device, Patent No. 201580007754.2 proposes an induction heating device that heats specialty cigarette products through electromagnetic induction. Specifically, an induction coil and a capacitor are connected in series or parallel to form an LC oscillation to generate an alternating current, which generates an alternating magnetic field in the coil, inducing heat in a susceptor and heating the cigarette product. Summary of the Invention

[0005] One embodiment of the present application is an aerosol generating device configured to heat an aerosol-generating product to generate a smoking aerosol, comprising: a cavity for receiving an aerosol-generating product; a battery cell including a first electrode and a second electrode; a first switch transistor and a second switch transistor; an LCC oscillator including an induction coil, a first capacitor, and a second capacitor, wherein a first end of the first capacitor is connected to the first electrode, a second end of the first capacitor is connected to the first end of the second capacitor, a second end of the second capacitor is connected to the second electrode, a first end of the induction coil is connected to the second end of the first capacitor, and a second end of the induction coil is connected to the first electrode via the first switch transistor and to the second electrode via the second switch transistor; the LCC oscillator configured such that the first switch transistor and the second switch transistor are alternately turned on and off to direct an alternating current through the induction coil, thereby driving the induction coil to generate a varying magnetic field; a susceptor configured to be penetrated by a varying magnetic field and to generate heat to heat an aerosol-generating product received within the cavity.

[0006] The aerosol generator described above uses an LCC oscillator to form an inverse conversion, which has a lower resonant frequency and higher efficiency than an LC oscillator.

[0007] In a preferred embodiment, the first switch transistor and the second switch transistor are configured to conduct the alternating current in a cyclical manner, each of the cyclical manners comprising: a positive half of the induction coil that charges the first capacitor and conducts current in a positive direction by turning on the first switch transistor and turning off the second switch transistor, thereby discharging the first capacitor and charging the second capacitor simultaneously; and a negative half that charges the second capacitor and conducts current in a negative direction of the induction coil after simultaneously charging the first capacitor and discharging the second capacitor by turning off the first switch transistor and turning on the second switch transistor.

[0008] In a preferred embodiment, the first switch transistor and the second switch transistor are turned on and off based on a zero-current switching inverter topology to direct an alternating current through the induction coil.

[0009] In a preferred embodiment, the LCC oscillator is maintained to be weakly inductive at all times.

[0010] In a preferred embodiment, the first switch transistor and the second switch transistor are switched non-simultaneously.

[0011] In a preferred embodiment, one of the first switch transistor and the second switch transistor is turned off earlier than the other is turned on.

[0012] In a preferred embodiment, the first and second capacitors have equal capacitance values.

[0013] In a preferred embodiment, the maximum voltage of the first capacitor and / or the second capacitor is higher than the output voltage of the battery cell.

[0014] In a preferred embodiment, the first capacitor comprises at least two parallel-connected capacitors; and / or the second capacitor comprises at least two capacitors connected in parallel.

[0015] In a preferred embodiment, The power supply further includes a controller configured to control the on / off of the first switch transistor and the second switch transistor in a PWM manner.

[0016] In a preferred embodiment, a resistor, through which a second terminal of the second capacitor and a second terminal of the second switch transistor are connected to a second electrode of the battery cell; an overcurrent monitoring unit for monitoring a current flowing through the resistor; and a controller configured to control the first switch transistor and the second switch transistor to be off when the current through the resistor is greater than a threshold value.

[0017] A further embodiment of the present application is an aerosol generating device configured to heat an aerosol-generating product to generate a smoking aerosol, comprising: a cavity for receiving an aerosol-generating product; an induction coil, a first capacitor, and a second capacitor, the first capacitor and the induction coil being connected in series to form a first LC oscillator, and the second capacitor and the induction coil being connected in series to form a second LC oscillator; a transistor switch configured to induce the first and second LC oscillators to oscillate using a zero-current switching inverter topology to form an alternating current through the induction coil to drive the induction coil to generate a varying magnetic field; a susceptor configured to be penetrated by a varying magnetic field and to generate heat to heat an aerosol-generating product received within said cavity. [Brief explanation of the drawings]

[0018] One or more embodiments are illustratively described by corresponding figures in the drawings, but these illustrative descriptions are not intended to be limiting of the embodiments, and elements / modules and steps in the drawings with the same reference numerals are intended to represent similar elements / modules and steps, and unless otherwise specified, the figures in the drawings are not meant to be drawn to scale. [Figure 1] 1 is a structural schematic diagram of an aerosol generating device provided in one embodiment of the present application. [Figure 2] FIG. 2 is a structural block diagram of one embodiment of the circuit in FIG. 1. [Figure 3]FIG. 3 is a schematic diagram of the basic components of one embodiment of the circuit in FIG. 2. [Figure 4] FIG. 4 is a schematic diagram of the forward current in one stage of the LCC oscillator in FIG. 3. [Figure 5] 4 is a schematic diagram of reverse current in one stage of the LCC oscillator in FIG. 3. FIG. [Figure 6] 4 is a schematic diagram of the current flowing through the induction coil in the oscillation process of the LCC oscillator in FIG. 3. [Figure 7] 4 is a schematic diagram of current and voltage fluctuations measured during the oscillation process of the LCC oscillator in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0019] In order to facilitate understanding of the present application, the present application will now be described in more detail with reference to the drawings and specific embodiments.

[0020] One embodiment of the present application proposes an aerosol generating device, the structure of which is shown in FIG. a cavity in which an aerosol-generating product A is removably received; an induction coil L for generating a varying magnetic field under an alternating current; a susceptor (30) extending at least partially within the cavity, the susceptor (30) being inductively coupled to an induction coil (L) and configured to be penetrated by a varying magnetic field to generate heat and heat an aerosol-generating product (A), such as a cigarette, and volatilize at least one component of the aerosol-generating product (A) to form a smoking aerosol; a battery cell 10 that is a rechargeable DC battery cell and is capable of outputting DC current; and a circuit 20 that is appropriately electrically connected to the rechargeable battery cell 10 to convert the direct current output from the battery cell 10 into an alternating current having an appropriate frequency and then supply it to the induction coil L.

[0021] Depending on the use configuration of the product, the induction coil L may comprise a helically wound cylindrical induction coil, as shown in FIG. 1. The helically wound cylindrical induction coil L may have a radius r in the range of about 5 mm to about 10 mm, and in particular, the radius r may be about 7 mm. The length of the helically wound cylindrical induction coil L may be in the range of about 8 mm to about 14 mm, and the number of turns of the induction coil L is in the range of about 8 turns to 15 turns. Accordingly, the internal volume is about 0.15 cm. 3 Approximately 1.10 cm 3 The range may be:

[0022] In a more preferred embodiment, the frequency of the alternating current supplied from the circuit 20 to the induction coil L is between 80 KHz and 400 KHz, and more specifically, the frequency may be in the range of about 200 KHz to 300 KHz.

[0023] In a preferred embodiment, the DC power supply voltage provided by the battery cell 10 is in the range of about 2.5V to about 9.0V, and the DC current amperage provided by the battery cell 10 is in the range of about 2.5A to about 20A.

[0024] In a preferred embodiment, the susceptor 30 is generally pin- or blade-shaped, which facilitates insertion into the aerosol-generating product A. The susceptor 30 may have a length of approximately 12 millimeters, a width of approximately 4 millimeters, and a thickness of approximately 0.5 millimeters, and may be made of grade 430 stainless steel (SS430). Alternatively, the susceptor 30 may have a length of approximately 12 millimeters, a width of approximately 5 millimeters, and a thickness of approximately 0.5 millimeters, and may be made of grade 430 stainless steel (SS430). In another variant, the susceptor 30 may be cylindrical or tubular. In use, its interior space forms a cavity for receiving the aerosol-generating product A, and generates a smoking aerosol by heating the outer periphery of the aerosol-generating product A. These susceptors may also be made of grade 420 stainless steel (SS420) and iron-nickel-containing alloy materials (e.g., Permalloy).

[0025] 1, the aerosol generating device further includes a holder 40 for arranging the induction coil L and the susceptor 30, and the material of the holder 40 may include a non-metallic material that can withstand high temperatures, such as PEEK or ceramic. In practice, the induction coil L is wound around and fixed to the outer wall of the holder 40. As shown in FIG. 1, the holder 40 has a hollow tubular shape, and the space in the hollow tubular portion forms the cavity for receiving the aerosol-generating product A.

[0026] In an alternative embodiment, the susceptor 30 is fabricated from the susceptible material described above, or is comprised of a heat-resistant substrate, such as a ceramic, having a susceptible material coating formed on its exterior surface by electroplating, deposition, or the like.

[0027] The structure and basic components of a preferred embodiment of the above circuit 20 may include the following: an LCC oscillator 24, a half-bridge 23, and a half-bridge driver 22, as shown in FIGS. The LCC oscillator 24 is composed of the induction coil L, the first capacitor C1, and the second capacitor C2. The LCC oscillator 24 generates an alternating current flowing through the induction coil L during the oscillation process, thereby generating an alternating magnetic field in the induction coil L and inducing heat in the susceptor 30. The half bridge 23 is a half bridge circuit made up of transistor switches, and includes a switch transistor Q1 and a switch transistor Q2 that are alternately switched on and off to cause the LCC oscillator 24 to oscillate. The half-bridge driver 22 is used to control the switch transistor Q1 and the switch transistor Q2 of the half-bridge 23 to alternately turn on and off based on a control signal from the MCU controller 21.

[0028] The complete connection scheme and detailed oscillation process of the LCC oscillator 24 in the above embodiment are shown in FIG. 3, specifically: Regarding connections, the first capacitor C1 has a first terminal connected to the positive electrode of the battery cell 10 and a second terminal connected to the first terminal of the second capacitor C2. The second terminal of the second capacitor C2 is grounded via a resistor R1. The first terminal of the switch transistor Q1 of the half bridge 23 is connected to the positive electrode of the battery cell 10, and the second terminal is connected to the first terminal of the switch transistor Q2, and the second terminal of the switch transistor Q2 is grounded via the resistor R1. Naturally, the controlled terminals of the switch transistor Q1 and the switch transistor Q2 are both connected to the half bridge driver 22 and are turned on and off by the driving of the half bridge driver 22. A first end of the induction coil L is connected to the second end of the switch transistor Q1, and a second end of the induction coil L is connected to the second end of the first capacitor C1. Furthermore, regarding the selection of hardware for the LCC oscillator 24, it is assumed that the maximum voltage values of the first capacitor C1 and the second capacitor C2 are significantly higher than the output voltage value of the battery cell 10. For example, in a typical implementation, the output voltage of the battery cell 10 used is usually about 4V, but the maximum voltage of the first capacitor C1 and the second capacitor C2 used is 30-80V.

[0029] In the LCC oscillator 24 with the above structure, the connection states of the first capacitor C1, the second capacitor C2, and the induction coil L change depending on the switching states of the switch transistor Q1 and the switch transistor Q2. Specifically, in FIG. 3, when the switch transistor Q1 is turned on and the switch transistor Q2 is turned off, the first capacitor C1 and the induction coil L together form a closed series LC circuit, while the second capacitor C2 and the induction coil L form a series LC circuit with both ends connected to the positive and negative electrodes of the battery cell 10. On the other hand, when the switch transistor Q1 is turned off and the switch transistor Q2 is turned on, the configured circuit is the opposite of the above state: the first capacitor C1 and the induction coil L form a series LC circuit with both ends connected to the positive and negative electrodes of the battery cell 10, while the second capacitor C2 and the induction coil L together form a closed series LC circuit. In each of the different states, the first capacitor C1 and the second capacitor C2 can both form their respective LC circuits with the induction coil L. However, during the oscillation process of each LC circuit, the direction and period of the generated current flowing through the induction coil L are the same, and they jointly form an alternating current flowing through the induction coil L.

[0030] Specifically, the control steps of the oscillation process with the above LCC oscillator 24 are different from those of a general series or parallel LC oscillator. Furthermore, in a preferred embodiment of the present application, the complete oscillation process of the LCC oscillator 24 is described through the switching operations of the switch transistor Q1 and the switch transistor Q2, including:

[0031] In S10, the switch transistor Q1 is turned on and the switch transistor Q2 is kept off, and in this state, the LCC oscillator 24 specifically completes the following two processes.

[0032] In step S11, as shown in Figure 4, when the switch transistor Q1 is turned on and the switch transistor Q2 is turned off, the battery cell 10 charges the second capacitor C2 with a current i1, and the first capacitor C1 discharges with a current i2. During this process, a current flows from left to right through the induction coil L shown in Figure 4, forming a positive current. In this step S11, the first capacitor C1 starts discharging when the switch transistor Q1 is turned on and completes discharging when the voltage difference between both ends becomes zero. The second capacitor C2 stops charging when the voltage across it increases to be equal to the output voltage of the battery cell 10, and at this time, the current through the induction coil L reaches its maximum resonant peak.

[0033] In S12, even after step S11 is completed, switch transistor Q1 remains on and switch transistor Q2 remains off, and induction coil L discharges in the same direction as current i2 in FIG. 4 to charge first capacitor C1, so the current flowing in the forward direction through induction coil L gradually decreases until it becomes zero due to the discharge of induction coil L. In this stage, because first capacitor C1 was completely discharged in step S11, there is almost no impedance between induction coil L and the circuit formed with first capacitor C1 via switch transistor Q1. Therefore, in this stage S12, induction coil L mainly discharges to charge first capacitor C1, and the current flowing through induction coil L during the discharge process is the same as current i2 in step S11. In step S11, second capacitor C2 was charged to substantially the same output voltage as battery cell 10, and in this stage S12, induction coil L provides a slight compensation for second capacitor C2, but this compensation is essentially negligible.

[0034] In the complete process consisting of step S11 and step S12, the total current flowing through the induction coil L increases in a positive direction from 0 to a maximum, and then gradually decreases to 0 due to the discharge of the induction coil L, and the direction of the current flowing through the induction coil L is always positive from left to right.

[0035] In step S20, after step S10 is completed, the switch transistor Q1 is turned off and the switch transistor Q2 is turned on. Specifically, the following two-stage process is completed:

[0036] In S21, when the switch transistor Q2 is turned on, a circuit of currents i3 and i4 shown in Figure 5 is formed within the LCC oscillator 24. According to the current path shown in Figure 5, current i3 forms a circuit by passing from the positive terminal of the battery cell 10 through the first capacitor C1, induction coil L, switch transistor Q2, and then returning to the negative terminal of the battery cell 10 via ground. Similarly, current i4 forms a circuit by passing from the positive terminal of the second capacitor C2 counterclockwise in the figure through the induction coil L and switch transistor Q2, and then returning to the negative terminal of the second capacitor C2. During this process, a current is formed that flows from right to left through the induction coil L shown in Figure 5, which is opposite to the current direction in Figure 4 and can be considered a negative current.

[0037] Step S21 also includes both charging the first capacitor C1 and discharging the second capacitor C2. When the voltage of the first capacitor C1 increases to be equal to the output voltage of the battery cell 10 and when the voltage difference across the second capacitor C2 becomes zero, the current in the induction coil L reaches a maximum resonant peak.

[0038] In S22, after completing step S21, the switch transistor Q2 continues to be turned on, and the induction coil L reversely charges the second capacitor C2, so that the current flowing in the negative direction through the induction coil L gradually decreases until the induction coil L discharges to zero.

[0039] In the complete process consisting of steps S21 and S22 of step S20, the total current flowing through the induction coil L similarly increases in the reverse direction from 0 to a maximum, and then gradually decreases to 0 as the induction coil L discharges.

[0040] In the above, the current switching in the oscillation of the LCC oscillator 24 is controlled by the half bridge 23 consisting of the switch transistor Q1 and the switch transistor Q2. Of course, based on the same embodiment, those skilled in the art can replace or use a full bridge circuit including four switch transistors to drive the oscillation of the LCC oscillator 24.

[0041] Therefore, in the oscillation process of the LCC oscillator 24 described above, the fluctuation of the current flowing through the induction coil L includes four parts in one complete current cycle, as shown in Figure 6, which respectively correspond to the above-mentioned stages S11 / S12 / S21 / S22 in Figure 6. In the above-mentioned steps S10 and S20, the on / off states of the switch transistor Q1 and the switch transistor Q2 are alternately and cyclically switched, thereby cyclically generating the oscillation process of the above-mentioned stages S11 / S12 / S21 / S22 in the LCC oscillator 24 and generating an alternating current flowing through the induction coil L.

[0042] Therefore, as can be seen from the above control process, the LCC oscillator 24 of the present application generates inverse conversion using a ZCS (zero current switching) inverter topology, which is different from the ZVS (zero voltage switching) inverter topology of conventional LC oscillators. The switch transistors Q1 and Q2 are configured to switch on and off when the current flowing through the induction coil L is zero.

[0043] In the preferred embodiment shown in FIG. 3, the first capacitor C1 and the second capacitor C2 each have one capacitor. In other alternative embodiments, the first capacitor C1 or the second capacitor C2 may each comprise two or three capacitors with smaller relative capacitances connected in parallel. For example, if multiple small capacitors are used instead of the relatively large capacitor that would otherwise be required for the first capacitor C1, the capacitances of the multiple small capacitors are the same or nearly the same. As the oscillation frequency of the LCC oscillator 24 changes, each capacitor exhibits a significantly lower, varying ESR (equivalent resistance) than a single capacitor. Specifically, the ESR is relatively high at low frequencies and relatively low at high frequencies, which may be advantageous for preventing spike pulses. Furthermore, using multiple small capacitors instead of the relatively large capacitor that would otherwise be required is advantageous for lowering the resonant frequency of the LCC oscillator 24.

[0044] The circuit 20 using the LCC oscillator 24 forms an inverse transformation using ZCS technology in implementation, and has a resonant frequency that is approximately half that of a conventional LC series / parallel oscillation using a single capacitor. Typically, when the frequency of the LC series / parallel oscillation is about 380 Hz, the oscillation frequency of the LCC oscillator 24 is about 190 kHz, which is advantageous for both synchronous detection and control of the MCU controller 21.

[0045] Furthermore, during the above oscillation process, the fluctuations of the resonant voltage and current of the LCC oscillator 24 obtained by detection are shown in Figure 7. The resonant voltage leads the resonant current by about 1 / 4 of a period, and the entire LCC oscillator 24 exhibits weak inductivity. "Capacitive" and "inductive" are electrical terms related to a series-parallel circuit of an electronic device (e.g., an LC oscillator or the above-mentioned LCC oscillator 24). When the capacitive reactance of a series-parallel circuit is greater than the inductive reactance, the circuit is "capacitive," and when the inductive reactance is greater than the capacitive reactance, the circuit is inductive. A "weakly inductive" state is when the inductive reactance and the capacitive reactance are substantially close to each other, and the inductive reactance is slightly greater than the capacitive reactance, rather than much greater than it.

[0046] In a more preferred embodiment, during the execution of steps S12 and S22, switch transistor Q1 / switch transistor Q2, which should normally be turned off when the current becomes zero due to the discharge of induction coil L, can be turned off a little earlier, without simultaneously turning on the other. For example, as shown in FIG. 6, in step S12, at time t2, when the current is close to but not yet zero due to the discharge of induction coil L, switch transistor Q1 is turned off early. Thereafter, at time t3, when the current becomes zero due to the discharge of induction coil L, switch transistor Q2 remains on. In practice, the switch transistor Q2 can be turned off about 0.1 to 0.5 μs earlier. Because the induction coil L has not yet completely discharged to zero, switch transistor Q2 enters a freewheeling state, allowing the small amount of electrical energy remaining in induction coil L to charge second capacitor C2. After the above 0.1 to 0.5 μs of freewheeling (the so-called dead time period), the voltage difference across the switch transistor Q2 becomes virtually zero. If the switch transistor Q2 is turned on at this point, the degree of wear is greatly reduced and the safety effect is greatly improved.

[0047] The above-described early turn-off method corresponds to the characteristics of FIG. 7, in which the voltage leads the current and the LCC is weakly inductive. When the LCC oscillator 24 is turned off when the current is zero, the voltage exceeds the current, making it capacitive. Turning off the switch transistor early creates a protection or buffer zone, which is advantageous for eliminating undesirable factors such as capacitive and early turns. This prevents the switch transistors Q1 and Q2 from switching on and off simultaneously, providing a 0.1 to 0.5 μs protection time delay between the time the former turns off and the time the latter turns on. This protects the switch transistors just before they turn on. On the other hand, the LCC oscillator 24 is always weakly inductive, never becoming capacitive or strongly inductive, improving efficiency.

[0048] 2 and 3, in order to accurately detect details such as the oscillation process and period of the LCC oscillator 24, the embodiment further includes a synchronization unit 25 that serves to synchronously detect changing physical parameters such as current, voltage, or period during the oscillation process of the LCC oscillator 24. Specifically, in the embodiment shown in FIG. 3, the synchronization unit 25 mainly includes an operational amplifier U1, whose detection signal input terminal is connected to the second end of the induction coil L, and after undergoing processes such as diode rectification, the operational amplifier U1 can sample and detect the electrical signal therefrom.

[0049] Alternatively, in an optional embodiment, the reference signal terminal of the operational amplifier U1 can be directly set to 0, thereby making it a zero-cross comparator for detecting the time when the oscillation current of the LCC oscillator 24 is 0, and then the MCU controller 21 obtains the changing physical parameters such as the current, voltage or period of the LCC oscillator 24 based on this detection result, along with the zero-cross time shown in FIG. 6.

[0050] Furthermore, referring to the embodiment shown in FIG. 3, the half-bridge driver 22 is a switch transistor driver with a common model number FD2204, which is controlled by the MCU controller 21 in a PWM manner, and alternately outputs high level and low level through the third and tenth I / O ports according to the pulse width of the PWM, thereby driving the on-time of the switch transistor Q1 and the switch transistor Q2, and controlling the oscillation of the LCC oscillator 24.

[0051] As can be seen from the above detailed control steps, the LCC inverse conversion process is symmetrical, and the duty cycle is close to 50%. Accordingly, the MCU controller 21 can send a PWM control signal with a 50% duty cycle to the half-bridge driver 22 to drive the half-bridge 23 to switch in this manner.

[0052] Further, referring to the preferred embodiment shown in FIGS. 2 and 3, the circuit 20 further includes an overcurrent monitoring unit 26, which is used to monitor the current value of the main circuit, which is the circuit consisting of the battery cell 10 and the LCC oscillator 24, in order to prevent safety problems that may occur when the current becomes excessive.

[0053] In the embodiment of Figure 3, the overcurrent monitoring unit 26 is first implemented based on the resistor R1, and during the LCC oscillation process, it always forms a circuit with the negative electrode of the battery cell 10 by being grounded via the resistor R1. Therefore, during the oscillation process, the resistor R1 is always conductive with the LCC oscillator 24, and the current of the main circuit can be obtained by detecting the ground voltage of the resistor R1. In FIG. 3, the overcurrent monitoring unit 26 includes two operational amplifiers: operational amplifier U2 and operational amplifier U3. In practice, one is used for comparison, and the other is used for output amplification. In the preferred embodiment of FIG. 3, operational amplifier U2 is primarily used to sample the voltage across R1 and generate an output signal representing the current value of the main circuit through an operation. The signal output from operational amplifier U2 is then further amplified by operational amplifier U3, and then sampled and acquired by the MCU controller 21.

[0054] Alternatively, in another modified embodiment, the operational amplifier U3 can also be used as a comparison function to compare the voltage signal output from the operational amplifier U2 with a threshold value. If the comparison result is less than the threshold value, it outputs a low-level voltage signal to the MCU controller 21, indicating that the current in the main circuit is below a predetermined safety threshold; if the comparison result is greater than the threshold value, it outputs a high-level voltage signal to the MCU controller 21, indicating that the current in the main circuit exceeds the predetermined safety threshold. Based on this result, the MCU controller 21 controls the half bridge 23 to turn off and stop oscillation, thereby ensuring the safety of the main circuit.

[0055] Furthermore, the circuit 20 shown in FIG. 3 also includes resistors, capacitors, etc. that are not labeled, but these components perform the functions of conventional general-purpose components such as current limiting and filtering in the circuit 20, and will be easily understood by those skilled in the art, so they will not be described in detail.

[0056] It should be noted that although the specification and drawings of this application show preferred embodiments of this application, this application is not limited to the embodiments described in this specification, and further, a person skilled in the art may make improvements and modifications based on the above description, and all such improvements and modifications shall fall within the scope of protection of the appended claims of this application.

Claims

1. 1. An aerosol generating device configured to heat an aerosol-generating product to generate a smoking aerosol, comprising: a cavity for receiving an aerosol-generating product; a battery cell including a first electrode and a second electrode; a first switch transistor and a second switch transistor; an LCC oscillator including an induction coil, a first capacitor and a second capacitor having equal capacitance values, wherein a first end of the first capacitor is connected to the first electrode, a second end of the first capacitor is connected to the first end of the second capacitor, a second end of the second capacitor is connected to the second electrode, a first end of the induction coil is connected to the second end of the first capacitor, and a second end of the first capacitor is connected to the first electrode via the first switch transistor and to the second electrode via the second switch transistor, the first capacitor includes at least two capacitors connected in parallel, and the second capacitor includes at least two capacitors connected in parallel; the LCC oscillator configured such that the first switch transistor and the second switch transistor are alternately turned on and off to direct an alternating current through the induction coil, thereby driving the induction coil to generate a varying magnetic field; a susceptor configured to be penetrated by a varying magnetic field and to generate heat to heat an aerosol-generating product received within the cavity.

2. The first switch transistor and the second switch transistor are configured to conduct the alternating current in a cyclical manner, each of the cyclical manners comprising: a positive half that simultaneously discharges the first capacitor and charges the second capacitor by turning on the first switch transistor and turning off the second switch transistor, and then charges the first capacitor and conducts current in a positive direction of the induction coil; 2. The aerosol generating device of claim 1, further comprising: a negative half that charges the second capacitor and conducts current in the negative direction of the induction coil after simultaneously charging the first capacitor and discharging the second capacitor by turning off the first switch transistor and turning on the second switch transistor.

3. 3. The aerosol generating device of claim 1 or 2, wherein the first switch transistor and the second switch transistor are turned on and off based on a zero-current switching inverter topology to direct an alternating current to flow through the induction coil.

4. 3. The aerosol generating device according to claim 1, wherein the LCC oscillator is always maintained to be weakly inductive.

5. 3. The aerosol generating device according to claim 2, wherein the first switch transistor and the second switch transistor are not switched simultaneously.

6. 6. The aerosol generating device according to claim 5, wherein one of the first switch transistor and the second switch transistor is turned off earlier than the other is turned on.

7. 2. The aerosol generating device according to claim 1, wherein the maximum voltage of the first capacitor and / or the second capacitor is higher than the output voltage of the battery cell.

8. 3. The aerosol generating device according to claim 1, further comprising a controller configured to control the on / off of the first switch transistor and the second switch transistor in a PWM manner.

9. a resistor, through which a second end of the second capacitor and a second end of the second switch transistor are connected to a second electrode of the battery cell; an overcurrent monitoring unit for monitoring a current flowing through the resistor; 3. The aerosol generating device according to claim 1 or 2, further comprising: a controller configured to control the first switch transistor and the second switch transistor to be off when the current flowing through the resistor is greater than a threshold value.

10. 1. An aerosol generating device configured to heat an aerosol-generating product to generate a smoking aerosol, comprising: a cavity for receiving an aerosol-generating product; an induction coil, a first capacitor and a second capacitor having equal capacitance, the first capacitor and the induction coil being connected in series to form a first LC oscillator, the second capacitor and the induction coil being connected in series to form a second LC oscillator, the first capacitor including at least two capacitors connected in parallel, and the second capacitor including at least two capacitors connected in parallel; a transistor switch configured to induce the first and second LC oscillators to oscillate using a zero-current switching inverter topology to form an alternating current through the induction coil to drive the induction coil to generate a varying magnetic field; a susceptor configured to be penetrated by a varying magnetic field and to generate heat to heat an aerosol-generating product received within the cavity.

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