Aerosol generating device

Abstract

The invention provides an aerosol generating device. The aerosol generating device is configured to heat an aerosol generating product to generate aerosol for suction. Comprising a susceptor configured to be penetrated by a changing magnetic field to generate heat so as to heat an aerosol generating article; a series LC oscillator or a series LCC oscillator having an inductance coil configured to guide a varying current through the inductance coil to drive the inductance coil to generate a varying magnetic field; and a circuit configured to determine the oscillation frequency of the series LC oscillator or the series LCC oscillator according to the change rate of the oscillation voltage of the series LC oscillator or the series LCC oscillator. According to the aerosol generating device, the oscillation frequency is determined according to the change rate of the oscillation voltage.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of heat-not-burn low-temperature smoking devices, and in particular to an aerosol generating device. Background Art

[0002] Smoking articles (eg, cigarettes, cigars, etc.) burn tobacco during use to produce tobacco smoke. Attempts have been made to replace these tobacco-burning articles by creating products that release compounds without combustion.

[0003] An example of such a product is a heating device that releases compounds by heating rather than burning a material. For example, the material may be tobacco or other non-tobacco products that may or may not contain nicotine. In known devices, tobacco products are heated by a heater that generates heat through electromagnetic induction to generate an aerosol for inhalation. In one prior art embodiment of the above heating device, Patent No. 201580007754.2 proposes an induction heating device for electromagnetic induction heating of special tobacco products; specifically, an induction coil and a capacitor are connected in series or in parallel to form an LC oscillation to form an alternating current, so that the coil generates an alternating magnetic field to induce the receptor to heat and heat the tobacco product. The above known heating devices usually use an operational amplifier to synchronously output the oscillation voltage of the LC oscillation or use a zero-crossing comparator to detect the time when the oscillation voltage crosses zero, and then the control chip samples the above result to calculate the frequency of the LC oscillation. In practice, since the frequency of the LC oscillation is very high, approximately 200 to 400 kHz, the control chip must be able to sample the instantaneous output results of the above comparators and amplifiers. Therefore, the sampling speed of the control chip must be around tens of MHz to avoid missing the result signal of the instantaneous output of the comparator or amplifier. Therefore, it is not advisable to track the frequency of the LC oscillation in this way. Summary of the Invention

[0004] An embodiment of the present application provides an aerosol generating device configured to heat an aerosol generating article to generate an aerosol for inhalation; comprising:

[0005] a susceptor configured to be penetrated by the changing magnetic field and generate heat to heat the aerosol-generating article;

[0006] A series LC oscillator or a series LCC oscillator having an inductor coil, configured to direct a varying current to flow through the inductor coil to drive the inductor coil to generate a varying magnetic field;

[0007] The circuit is configured to determine the oscillation frequency of the series LC oscillator or series LCC oscillator according to the rate of change of the oscillation voltage of the series LC oscillator or series LCC oscillator. The above aerosol generating device determines the oscillation frequency according to the rate of change of the oscillation voltage.

[0008] In a preferred embodiment, the circuit comprises:

[0009] an active differential unit configured to detect a rate of change of an oscillation voltage of the series LC oscillator or the series LCC oscillator, and output a high-level signal when the rate of change of the oscillation voltage is greater than a preset threshold;

[0010] The controller is configured to determine the oscillation frequency of the series LC oscillator or the series LCC oscillator according to the interval time of the high-level signal.

[0011] In a preferred embodiment, the active differential unit includes: an active differential module and a comparator; wherein,

[0012] The active differential module is configured to detect the rate of change of the oscillation voltage of the series LC oscillator or the series LCC oscillator;

[0013] The comparator is configured to compare the change rate of the oscillating voltage with a preset threshold value, and output a high level signal to the controller when the change rate of the oscillating voltage is greater than the preset threshold value.

[0014] In a preferred embodiment, the active differential module includes: a first capacitor, a first resistor, a second capacitor, a second resistor and an operational amplifier; wherein,

[0015] A first end of the first capacitor is connected to the series LC oscillator or the series LCC oscillator, and a second end is connected to the first end of the first resistor;

[0016] The first input terminal of the operational amplifier is connected to the second end of the first resistor, and the output terminal is connected to the comparator;

[0017] A first end of the second capacitor is connected to the second end of the first resistor, and a second end of the second capacitor is connected to the output end of the operational amplifier;

[0018] The first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the output end of the operational amplifier.

[0019] In a preferred embodiment, the active differential unit further comprises:

[0020] The access module includes: a first diode, a third resistor and a fourth resistor; wherein,

[0021] The first diode has a first end connected to the series LC oscillator or the series LCC oscillator, a second end connected to the first end of the third resistor, and is configured to only allow current to flow from the series LC oscillator or the series LCC oscillator to the third resistor;

[0022] The second end of the third resistor is connected to the active differential module;

[0023] A first end of the fourth resistor is connected to the second end of the third resistor, and a second end of the fourth resistor is grounded.

[0024] In a preferred embodiment, the access module further includes: a voltage regulator tube; a first end of the voltage regulator tube is connected to the second end of the third resistor, and a second end of the voltage regulator tube is connected to the second end of the fourth resistor.

[0025] In a preferred embodiment, the preset threshold is the output value of the active differential module when the rate of change of the oscillating voltage is 0.

[0026] In a preferred embodiment, the controller is configured to adjust the oscillation frequency of the series LC oscillator or the series LCC oscillator so that the oscillation frequency of the series LC oscillator or the series LCC oscillator is the same as or substantially close to a preset frequency.

[0027] Another embodiment of the present application further provides a method for controlling an aerosol generating device, the aerosol generating device comprising:

[0028] a susceptor configured to be penetrated by the changing magnetic field and generate heat to heat the aerosol-generating article;

[0029] A series LC oscillator or a series LCC oscillator having an inductor coil, configured to direct a varying current to flow through the inductor coil to drive the inductor coil to generate a varying magnetic field;

[0030] The method comprises:

[0031] detecting a rate of change of an oscillation voltage of the LCC oscillator or the series LC oscillator;

[0032] When the oscillation voltage change rate is higher than a preset value, a high level signal is generated;

[0033] The oscillation frequency of the LCC oscillator or the series LC oscillator is determined according to the interval time of the high-level signal.

[0034] In a preferred embodiment, it also includes:

[0035] The oscillation frequency of the series LC oscillator or the series LCC oscillator is adjusted so that the oscillation frequency of the series LC oscillator or the series LCC oscillator is the same as or substantially close to a preset frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0037] Figure 1 Schematic diagram of the structure of an aerosol generating device provided in one embodiment of the present application;

[0038] Figure 2 yes Figure 1 A structural block diagram of an embodiment of the circuit;

[0039] Figure 3 yes Figure 2 A schematic diagram of the basic components of one embodiment of the circuit;

[0040] Figure 4 yes Figure 3 Schematic diagram of the forward current in one stage of the LCC oscillator;

[0041] Figure 5 yes Figure 3 Schematic diagram of the reverse current in one stage of the LCC oscillator;

[0042] Figure 6 yes Figure 3 Schematic diagram of the resonant current of the LCC oscillator in series;

[0043] Figure 7 yes Figure 3 Schematic diagram of the changes in resonant current and resonant voltage during the series LCC oscillator test;

[0044] Figure 8 It is a schematic diagram of the signal changes in the three stages of the active differential unit;

[0045] Figure 9 It is a schematic diagram of a control method of an aerosol generating device proposed in an embodiment. DETAILED DESCRIPTION

[0046] In order to facilitate the understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and specific implementation methods.

[0047] One embodiment of the present application provides an aerosol generating device, the structure of which can be seen in Figure 1 Shown, including:

[0048] a chamber in which the aerosol-generating article A is removably received;

[0049] The inductor L is used to generate a changing magnetic field under an alternating current;

[0050] The susceptor 30 extends at least partially within the chamber and is configured to be inductively coupled to the inductor coil L. When penetrated by the changing magnetic field, it generates heat, thereby heating the aerosol-generating article A, such as a cigarette, to volatilize at least one component of the aerosol-generating article A, thereby forming an aerosol for inhalation.

[0051] Battery cell 10 is a rechargeable DC battery cell that can output DC current;

[0052] The circuit 20 is connected to the rechargeable battery cell 10 via appropriate electrical connections, and is used to convert the direct current output from the battery cell 10 into an alternating current with a suitable frequency and then supply it to the inductor L.

[0053] According to the settings in the product use, the inductor coil L may include a cylindrical inductor coil wound into a spiral shape, such as Figure 1 As shown in . The helically wound cylindrical inductor 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 inductor coil L may be in the range of about 8 mm to about 14 mm, and the number of turns of the inductor coil L may be in the range of about 8 turns to 15 turns. Accordingly, the inner volume may be about 0.15 cm 3 to approximately 1.10cm 3 within the range.

[0054] In a more preferred embodiment, the frequency of the alternating current supplied by the circuit 20 to the inductor L is between 80 KHz and 400 KHz; more specifically, the frequency may be in the range of approximately 200 KHz to 300 KHz.

[0055] In a preferred embodiment, the DC supply voltage provided by the battery cell 10 is in the range of about 2.5V to about 9.0V, and the amperage of the DC current provided by the battery cell 10 is in the range of about 2.5A to about 20A.

[0056] In a preferred embodiment, the susceptor 30 is generally pin- or blade-shaped, which is advantageous for insertion into the aerosol-generating article A. Furthermore, the susceptor 30 may have a length of approximately 12 mm, a width of approximately 4 mm, and a thickness of approximately 0.5 mm, and may be made of grade 430 stainless steel (SS430). Alternatively, the susceptor 30 may have a length of approximately 12 mm, a width of approximately 5 mm, and a thickness of approximately 0.5 mm, and may be made of grade 430 stainless steel (SS430). In other variations, the susceptor 30 may also be cylindrical or tubular; in use, its interior space forms a chamber for receiving the aerosol-generating article A, and generates an aerosol for inhalation by heating the outer periphery of the aerosol-generating article A. These susceptors may also be made of grade 420 stainless steel (SS420) or an iron / nickel alloy (such as Permalloy).

[0057] exist Figure 1 In the embodiment shown, the aerosol generating device further includes a bracket 40 for arranging the inductor coil L and the sensor 30. The material of the bracket 40 may include a high-temperature resistant non-metallic material such as PEEK or ceramic. In practice, the inductor coil L is wound around the outer wall of the bracket 40 and then fixed. At the same time, according to Figure 1 As shown, the support 40 has a hollow tubular shape, and the hollow part of the tubular shape forms the chamber for receiving the aerosol generating product A.

[0058] In an optional implementation, the susceptor 30 is made of the above-mentioned sensitive materials, or is obtained by forming a sensitive material coating on the outer surface of a heat-resistant base material such as ceramic by electroplating, deposition, etc.

[0059] The structure and basic components of the circuit 20 in a preferred embodiment can be seen in Figures 2 to 3 Shown, including:

[0060] An LCC oscillator 24 is composed of the inductor L and the first and second capacitors C1 and C2. The LCC oscillator 24 is configured to generate an alternating current flowing through the inductor L during oscillation, thereby causing the inductor L to generate an alternating magnetic field to induce heating of the susceptor 30.

[0061] The half-bridge 23 is a half-bridge circuit composed of transistor switches, including a switch tube Q1 and a switch tube Q2, which are used to oscillate the LCC oscillator 24 by alternating on-off switching;

[0062] The half-bridge driver 22 is used to control the switch tubes Q1 and Q2 of the half-bridge 23 to alternately turn on and off according to the control signal of the MCU controller 21 .

[0063] The complete connection mode and detailed oscillation process of the LCC oscillator 24 in the above embodiment are shown in FIG. Figure 3 shown; specifically,

[0064] In terms of connection, the first end of the first capacitor C1 is connected to the positive electrode of the battery cell 10, and the second end is connected to the first end of the second capacitor C2; the second end of the second capacitor C2 is grounded through the resistor R1;

[0065] The first end of the switch Q1 of the half-bridge 23 is connected to the positive electrode of the battery cell 10, and the second end is connected to the first end of the switch Q2. The second end of the switch Q2 is grounded via the resistor R1. Of course, the controlled ends of the switch Q1 and the switch Q2 are both connected to the half-bridge driver 22, and are then turned on and off by the half-bridge driver 22.

[0066] The first end of the inductor L is connected to the second end of the switch Q1, and the second end is connected to the second end of the first capacitor C1. Furthermore, in the hardware selection of the LCC oscillator 24, the maximum voltage of the first capacitor C1 and the second capacitor C2 is much greater than the output voltage of the battery cell 10. For example, in a typical implementation, the output voltage of the battery cell 10 is generally around 4V, while the maximum voltage of the first capacitor C1 and the second capacitor C2 is 30-80V.

[0067] In the LCC oscillator 24 of the above structure, when the switch tube Q1 and the switch tube Q2 are switched, the connection state between the first capacitor C1 and the second capacitor C2 and the inductor L changes. Figure 3 When the switch Q1 is on and the switch Q2 is off, the first capacitor C1 and the inductor L together form a closed series LC circuit, while the second capacitor C2 and the inductor L form a series LC circuit with both ends connected to the positive and negative poles of the battery cell 10. When the switch Q1 is off and the switch Q2 is on, the circuit formed is the opposite of the above state. The first capacitor C1 and the inductor L form a series LC circuit with both ends connected to the positive and negative poles of the battery cell 10, while the second capacitor C2 and the inductor L together form a closed series LC circuit. In their different states, the first capacitor C1 and the second capacitor C2 can each form their own LC circuit with the inductor L. However, during the oscillation process, the direction and period of the current generated by their respective LC circuits flowing through the inductor L are the same, and thus they together form an alternating current flowing through the inductor L.

[0068] Specifically, the control steps of the oscillation process of the above LCC oscillator 24 are different from those of conventional series or parallel LC oscillators. Further, in a preferred embodiment of the present application, the complete oscillation process of the LCC oscillator 24 is described by switching the switch tubes Q1 and Q2; including:

[0069] S10, turning on the switch tube Q1 and keeping the switch tube Q2 off, in this state the LCC oscillator 24 completes the following two processes. Specifically,

[0070] S11: If Figure 4 As shown, when the switch tube Q1 is turned on and the switch tube Q2 is turned off, the battery cell 10 charges the second capacitor C2 through the current i1, and at the same time, the first capacitor C1 is discharged through the current i2. Figure 4 The current flowing from left to right through the inductor L can be recorded as the positive current. In this stage S11, the first capacitor C1 begins to discharge when the switch Q1 turns on, and the discharge is completed when the voltage difference between the two ends reaches zero. The charging stops when the voltage across the second capacitor C2 increases to equal the output voltage of the battery cell 10. At this time, the current in the inductor L reaches its maximum resonant peak.

[0071] S12: After the completion of stage S11, the switch tube Q1 is kept on and the switch tube Q2 is kept off. The inductor L will Figure 1 The inductor L discharges in the same direction as the current i2 in stage S11 to charge the first capacitor C1, thereby gradually reducing the current flowing in the positive direction through the inductor L until the current in the inductor L is discharged to zero. In this stage, since the first capacitor C1 has been fully discharged in stage S11, there is essentially no impedance between the inductor L and the loop formed by the switch tube Q1 and the first capacitor C1. Therefore, in this stage S12, the inductor L mainly discharges to charge the first capacitor C1. The current flowing through the inductor L during the discharge process is the same as the current i2 in stage S11. Since the second capacitor C2 has basically been charged to the same voltage as the output voltage of the battery cell 10 in stage S11, the inductor L will compensate the second capacitor C2 by a very small amount in this stage S12, but this is basically negligible.

[0072] During the entire process of stage S11 and stage S12, the total current flowing through the inductor L increases from 0 in the positive direction to the maximum, and then gradually decreases to 0 due to the discharge of the inductor L. The direction of the current flowing through the inductor L is always in the positive direction from left to right.

[0073] S20, after step S10 is completed, the switch tube Q1 is turned off and the switch tube Q2 is turned on, completing the following two-stage process. Specifically,

[0074] S21: The switch tube Q2 starts to conduct, and the LCC oscillator 24 generates Figure 5 The loop of current i3 and current i4 shown in FIG. Figure 5As shown in the current path, the current i3 flows from the positive electrode of the battery cell 10 through the first capacitor C1, the inductor L, the switch tube Q2, and then returns to the negative electrode of the battery cell 10 through the ground to form a loop; at the same time, the current i4 flows from the positive end of the second capacitor C2 in the counterclockwise direction as shown in the figure through the inductor L, the switch tube Q2, and then returns to the negative end of the second capacitor C2 to form a loop. In this process, a circuit is formed as follows: Figure 5 The current flowing from right to left through the inductor L is Figure 4 If the direction of the current is opposite, it can be recorded as a current in the negative direction.

[0075] Stage S21 includes 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 the voltage difference across the second capacitor C2 is 0, the current of the inductor L reaches the maximum resonant peak.

[0076] S22: After the completion of stage S21, the switch tube Q2 is kept turned on, and the inductor L will reversely charge the second capacitor C2, so that the current flowing through the inductor L in the negative direction gradually decreases until the inductor L is discharged to zero.

[0077] During the entire process of the stages S21 and S22 of step S20 , the total current flowing through the inductor L also increases from 0 to a maximum in the reverse direction, and then gradually decreases to 0 due to the discharge of the inductor L.

[0078] Therefore, during the oscillation of the above LCC oscillator 24, the change of the current flowing through the inductor L can be seen from Figure 6 As shown, a complete current cycle includes Figure 6 The four parts correspond to the above stages S11 / S12 / S21 / S22 respectively. The above steps S10 and S20 cyclically and alternately switch the on and off states of the switch tubes Q1 and Q2, so that the oscillation process of the above stages S11 / S12 / S21 / S22 can be cyclically generated in the LCC oscillator 24, forming an alternating current flowing through the inductor L.

[0079] Therefore, based on the above control process, it can be seen that the LCC oscillator 24 of the present application generates inversion based on the ZCS (zero current switching) inverter topology, which is different from the ZVS (zero voltage switching) inverter topology of the existing LC oscillator; and the switch tube Q1 and the switch tube Q2 are configured to perform on / off switching when the current flowing through the inductor coil L is 0.

[0080] exist Figure 3In the preferred embodiment shown, the number of the first capacitor C1 and the second capacitor is 1. In other optional embodiments, the first capacitor C1 or the second capacitor C2 can each include 2 or 3 capacitors with relatively smaller capacitance values ​​connected in parallel. For example, by replacing the originally required relatively large capacitor with multiple smaller capacitors for the first capacitor C1, their capacitances are equal or approximately equal; then, as the oscillation frequency of the LCC oscillator 24 changes, each can accordingly present an ESR (equivalent resistance) that is significantly reduced and changes compared to when only a single capacitor is used. Specifically, when the ESR is relatively high at low frequencies and relatively low at high frequencies, it may be beneficial for preventing spike pulses. And when multiple smaller capacitors are used to replace the originally required relatively large capacitor, it is beneficial to reduce the resonant frequency of the LCC oscillator 24.

[0081] The circuit 20 employing the aforementioned LCC oscillator 24 utilizes ZCS technology to achieve inversion, resulting in a resonant frequency that is substantially halved compared to current single-capacitor LC series / parallel oscillations. While the typical LC series / parallel oscillation frequency is approximately 380 Hz, the oscillation frequency of the aforementioned LCC oscillator 24 is approximately 190 kHz, which is advantageous for both synchronous detection and control by the MCU controller 21.

[0082] In the above oscillation process, the changes in the resonant voltage and current of the LCC oscillator 24 obtained by detection are shown in FIG. Figure 7 As shown, the resonant voltage leads the resonant current by approximately 1 / 4 cycle, and the overall LCC oscillator 24 exhibits weak inductive behavior. "Capacitive" and "inductive" are electrical terms related to parallel-parallel circuits of electronic components (such as LC oscillators or the aforementioned LCC oscillator 24). When the capacitive reactance of a parallel-parallel circuit is greater than the inductive reactance, the circuit exhibits "capacitive" behavior; when the inductive reactance is greater than the capacitive reactance, the circuit exhibits "inductive" behavior. A "weakly inductive" state refers to a state where the inductive reactance is approximately equal to the capacitive reactance and is slightly, but not significantly, greater than the capacitive reactance.

[0083] See further Figure 3 In the embodiment shown, the half-bridge driver 22 uses a commonly used FD2204 switch tube driver, which is controlled by the MCU controller 21 in a PWM manner. According to the PWM pulse width, the third and tenth I / O ports respectively alternately send high / low levels to drive the on-time of the switch tubes Q1 and Q2 to control the oscillation of the LCC oscillator 24.

[0084] From the above detailed control steps, the LCC inversion process is symmetrical, and the corresponding MCU controller 21 sends 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 way.

[0085] See further Figure 2In order to accurately detect the oscillation frequency of the LCC oscillator 24, the circuit 20 further includes an active differential unit 25. The detection process of the active differential unit 25 includes:

[0086] Based on the characteristics that the oscillation voltage gradually reaches its maximum and the current becomes zero at the same time, the rate of change of the oscillation voltage of the LCC oscillator 24 is first detected / derived;

[0087] When the rate of change or derivative of the voltage is compared with a preset threshold, a pulse interrupt signal is output to the MCU controller 21 when it is greater than the preset threshold;

[0088] The MCU controller 21 can obtain the oscillation frequency of the LCC oscillator 24 according to the time interval of the received interrupt signal.

[0089] The above process is implemented by Figure 3 The three submodules of the active differential unit 25 shown are implemented, specifically including:

[0090] The signal access module consists of diode D1, resistors R2 and R3, and a voltage regulator diode Z. Diode D1 allows the positive half-waveform voltage of the LCC oscillator 24 to be connected while filtering out the negative half-waveform voltage. Resistors R2 and R3 then divide the voltage. Z is a voltage regulator diode that prevents excessive input voltage and protects the subsequent circuits.

[0091] Active differential module, in Figure 3 The circuit uses a conventional active differential circuit with standard basic components, consisting of an operational amplifier U1, capacitor C3, resistors R4, R5, and R6. The operational amplifier U1, capacitor C3, and resistor R4 are essential components of the active differential module. The ratio of resistors R4 and R7 is 1 to avoid high peaks in the output, ensuring the flattest amplitude-frequency response and lowering the Q value. Capacitor C4 is used for voltage stabilization to prevent the op amp from self-oscillating.

[0092] The voltage signal Vout output by the active differential module during operation is:

[0093] Wherein, PP_LCC is the resonant voltage of the LCC oscillator 24. According to the principle of the calculation formula, the output result is the derivative of the resonant voltage of the LCC oscillator 24 with respect to time t and the result of the comprehensive calculation of the relevant device parameters in the active differential. Since the parameters of the relevant devices are given, the output result can be equivalent to the derivative of the voltage with respect to time, that is, the rate of change of the voltage.

[0094] Comparison output module, in Figure 3 The main part is comparator U2; when the Vout output by the active differential module is higher than the preset threshold, it outputs a high level.

[0095] To make it easier for technicians to understand, Figure 8 FIG. 1 shows a schematic diagram of signal changes of the active differential unit 25 in three stages detected in one embodiment; wherein,

[0096] Signal 1 is a graph of the voltage signal at the point between resistors R2 and R3 of the signal access module;

[0097] Signal 2 is a graph of the voltage signal Vout output by the operational amplifier U1 of the active differential module;

[0098] Signal 3 is a pulsed square wave pattern output by the comparator U2.

[0099] It should be noted that, according to the calculation formula of the output voltage signal Vout above, Figure 8 Signal 2 is negatively correlated with Signal 1; that is, when Signal 1 is rising, Signal 2 outputs a negative value until it reaches its peak, where Signal 2 is zero. When Signal 1 begins to decline from its peak, Signal 2 outputs a positive value. However, since the active differential module cannot output a negative signal, a reference value is added to the result during the calculation to ensure that Signal 2 always outputs a positive value. Comparator U2 uses this reference value as the basis for comparison. When Signal 2 begins to rise above this reference value and continues to increase, it indicates that Signal 1 is declining from its peak. After the decline ends, it outputs a low level. Based on the above description, the formula uses the signal output when Signal 1 reaches its peak, that is, when the voltage change rate is zero, as the reference value for the reference input of comparator U2, which is R6*2.5 / (R5+R6).

[0100] Based on the above, in practice, the MCU controller 21 does not need to actively perform high-frequency sampling to obtain the oscillation frequency of the LCC oscillator 24; instead, the pulsed square wave of signal 3 is sent to the MCU controller 21 as an interrupt signal. After receiving the signal, the MCU controller 21 calculates the interval (i.e., period) between adjacent square waves to obtain the frequency. The electrical term "interrupt signal" refers to a control method for chips or similar devices such as single-chip microcomputers. Specifically, when the CPU or receiving process receives the "interrupt signal," it temporarily stops other processes or tasks and, at the appropriate time, completes the function or process corresponding to the "interrupt signal" before returning to the original process or task.

[0101] In the above manner, the active differential module 25 detects the voltage change rate or derivative of the LCC oscillator 24, and then performs a comparison operation to generate a square wave with the same frequency, and sends the square wave as an interrupt signal to the MCU controller 21. After receiving the signal, the MCU controller 21 calculates the interval time (i.e., period) between adjacent square waves to obtain the frequency.

[0102] In yet another alternative implementation, the LCC oscillator 24 can replace or be equivalently replaced by a series LC oscillator with the same symmetrical resonance. Both oscillate at a 50% duty cycle and output a symmetrical sinusoidal or cosine-like voltage or current. Switching is performed using zero-current topology. An active differential unit 25 can be used to track the frequency of the series LC oscillator for easy control and adjustment.

[0103] Another embodiment of the present application also provides a control method for an aerosol generating device, wherein the aerosol generating device is driven by the above LCC oscillator 24 or a similar series LC oscillator to heat the sensor 30. Figure 9 As shown, the following steps are included:

[0104] S100, detecting the oscillation voltage change rate of the LCC oscillator 24 or the series LC oscillator;

[0105] S200, and compare the oscillation voltage change rate with a preset value, and generate a high level signal when it is higher than the preset value;

[0106] S300, calculating and detecting the oscillation frequency of the LCC oscillator 24 or the series LC oscillator by detecting the interval time of the high-level signal;

[0107] S400 , the MCU controller 21 may further adjust the oscillation frequency of the LCC oscillator 24 or the series LC oscillator to keep it the same as or substantially close to the preset frequency.

[0108] By tracking the detection frequency and adjusting it in real time, the oscillation frequency is kept the same as or basically close to the preset frequency, thereby maximizing efficiency.

[0109] It should be noted that the specification and drawings of this application provide preferred embodiments of the present application, but are not limited to the embodiments described in this specification. Furthermore, it is possible for a person skilled in the art to make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. An aerosol generating device configured to heat an aerosol generating article to generate an aerosol for inhalation; characterized in that include: a susceptor configured to be penetrated by the changing magnetic field and generate heat to heat the aerosol-generating article; An LC oscillator or LCC oscillator having an inductor coil, configured to direct a varying current to flow through the inductor coil to drive the inductor coil to generate a varying magnetic field; A circuit is configured to determine the oscillation frequency of the LC oscillator or LCC oscillator based on the rate of change of the oscillation voltage of the LC oscillator or LCC oscillator.

2. The aerosol generating device according to claim 1, wherein The LC oscillator or LCC oscillator further includes: A capacitor connected in series with the inductor includes at least two capacitors connected in parallel.

3. The aerosol generating device according to claim 1 or 2, wherein: The LC oscillator is a series LC oscillator, or the LCC oscillator is a series LCC oscillator.

4. The aerosol generating device according to claim 1 or 2, wherein: The circuit comprises: an active differential unit configured to detect a rate of change of an oscillation voltage of the LC oscillator or the LCC oscillator and output a high-level signal when the rate of change of the oscillation voltage is greater than a preset threshold; The controller is configured to determine the oscillation frequency of the LC oscillator or the LCC oscillator according to the interval time of the high-level signal.

5. The aerosol generating device according to claim 4, wherein The active differential unit includes: an active differential module and a comparator; wherein, The active differential module is configured to detect the rate of change of the oscillation voltage of the LC oscillator or the LCC oscillator; The comparator is configured to compare the change rate of the oscillating voltage with a preset threshold value, and output a high level signal to the controller when the change rate of the oscillating voltage is greater than the preset threshold value.

6. The aerosol generating device according to claim 5, wherein The active differential module includes: a first capacitor, a first resistor, a second capacitor, a second resistor and an operational amplifier; wherein, A first end of the first capacitor is connected to the LC oscillator or the LCC oscillator, and a second end of the first capacitor is connected to the first end of the first resistor; The first input terminal of the operational amplifier is connected to the second end of the first resistor, and the output terminal is connected to the comparator; A first end of the second capacitor is connected to the second end of the first resistor, and a second end of the second capacitor is connected to the output end of the operational amplifier; The first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the output end of the operational amplifier.

7. The aerosol generating device according to claim 5, wherein The active differential unit further comprises: The access module includes: a first diode, a third resistor and a fourth resistor; wherein, The first diode has a first end connected to the LC oscillator or the LCC oscillator, a second end connected to the first end of the third resistor, and is configured to only allow current to flow from the LC oscillator or the LCC oscillator to the third resistor; The second end of the third resistor is connected to the active differential module; A first end of the fourth resistor is connected to the second end of the third resistor, and a second end of the fourth resistor is grounded.

8. The aerosol generating device according to claim 7, wherein The access module further includes: a voltage regulator tube; a first end of the voltage regulator tube is connected to the second end of the third resistor, and a second end of the voltage regulator tube is connected to the second end of the fourth resistor.

9. The aerosol generating device according to claim 4, wherein: The preset threshold is the output value of the active differential module when the rate of change of the oscillating voltage is 0.

10. The aerosol generating device according to claim 4, wherein The controller is configured to adjust an oscillation frequency of the LC oscillator or the LCC oscillator so that the oscillation frequency of the LC oscillator or the LCC oscillator is the same as or substantially close to a preset frequency.

Images