Aerosol generating device and control method thereof

Abstract

The present application provides an aerosol generating device configured to generate an inhalable aerosol by heating an aerosol generating product, comprising: a susceptor configured to heat the aerosol generating product by passing through it with a variable magnetic field and generating heat; a series LC oscillator or series LCC oscillator having an induction coil configured to drive a variable current to pass through the induction coil so as to generate a variable magnetic field in the induction coil; and a circuit 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 aerosol generating device determines the oscillation frequency according to the rate of change of the oscillation voltage.

Description

Technology Field

[0001] This application claims priority to Chinese patent application No. 202011442673.4, filed with the Chinese Intellectual Property Office on December 8, 2020, under the title "Aerosol generating device and control method," the entire contents of which are incorporated by reference into this application.

[0002] The embodiments of the present application relate to a low-temperature smoking device that heats but does not burn, and in particular to an aerosol generating device and a method for controlling the same. Background Technology

[0003] Tobacco products (e.g., cigarettes, cigars, etc.) produce smoke by burning tobacco during use. People are attempting to replace these combustion products by creating products that release compounds without burning.

[0004] Examples of such products include heating devices that release compounds by heating materials without burning them. For example, the materials may be tobacco or other non-tobacco products, and these non-tobacco products may or may not contain nicotine. Known devices generate aerosols for inhalation by heating tobacco products through a heater heated by electromagnetic induction. In one embodiment of the prior art of the heating device, Chinese Patent No. 201580007754.2 specifically provides an induction heating device for a special tobacco product that heats a tobacco product by forming an AC current in a manner that forms an LC oscillation by connecting a capacitor in series or in parallel through an induction coil, thereby causing the coil to generate an alternating magnetic field and inducing a susceptor to generate heat. The prior art heating device generally uses a single operational amplifier to synchronously output the oscillation voltage of the LC oscillation or detects the zero-crossing time of the oscillation voltage through a zero-crossing comparator, and then calculates the frequency of the LC oscillation by sampling the above result by a control chip. In actual use, since the frequency of the LC oscillation is very high, around 200 to 400 KHz, the control chip must be able to sample when the comparator and amplifier instantaneously output the result. Consequently, the sampling rate of the control chip must be around tens of MHz so as not to miss the result signal instantaneously output by the comparator or amplifier, so it is not desirable to track the frequency of the LC oscillation in this way.

[0005] An embodiment of the present application relates to an aerosol generating device configured to generate an inhalable aerosol by heating an aerosol generating product, wherein

[0006] A susceptor configured to heat an aerosol generating product by passing through a variable magnetic field and generating heat;

[0007] A series LC oscillator or a series LCC oscillator having an induction coil configured to drive a variable current to pass through the induction coil so as to generate a variable magnetic field in the induction coil; and

[0008] The present invention provides an aerosol generating device comprising: a circuit configured to determine the oscillation frequency of the series LC oscillator or the series LCC oscillator according to the rate of change of the oscillation voltage of the series LC oscillator or the series LCC oscillator. In this way, the aerosol generating device determines the oscillation frequency according to the rate of change of the oscillation voltage.

[0009] In a preferred embodiment, the circuit is,

[0010] An active differentiation unit configured to detect the rate of change of the oscillation voltage of the above-mentioned series LC oscillator or series LCC oscillator and output a high-level signal when the rate of change of the oscillation voltage is greater than a preset threshold; and

[0011] It includes a controller configured to determine the oscillation frequency of the serial LC oscillator or serial LCC oscillator according to the interval time of the high-level signal.

[0012] In a preferred embodiment, the active differential unit is,

[0013] An active differential module configured to detect the rate of change of the oscillation voltage of the above-mentioned series LC oscillator or series LCC oscillator; and

[0014] It includes a comparator configured to compare the rate of change of the oscillation voltage with a preset threshold value and output a high-level signal to the controller when the rate of change of the oscillation voltage is greater than the preset threshold value.

[0015] In a preferred embodiment, the active differential module comprises a first capacitor, a first resistor, a second capacitor, a second resistor, and an operational amplifier, and

[0016] The first capacitor has a first terminal connected to the series LC oscillator or series LCC oscillator, and a second terminal connected to the first terminal of the first resistor.

[0017] The above operational amplifier has a first input terminal connected to the second terminal of the first resistor and an output terminal connected to the comparator, and

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

[0019] The first terminal of the second resistor is connected to the second terminal of the first resistor, and the second terminal is connected to the output terminal of the operational amplifier.

[0020] In a preferred embodiment, the active differential unit is,

[0021] It further includes an application module comprising a first diode, a third resistor, and a fourth resistor, and

[0022] The first diode is configured such that its first terminal is connected to the series LC oscillator or series LCC oscillator and its second terminal is connected to the first terminal of the third resistor, and that current is allowed only to flow from the series LC oscillator or series LCC oscillator to the third resistor.

[0023] The second terminal of the above third resistor is connected to the active differential module, and

[0024] The first terminal of the fourth resistor is connected to the second terminal of the third resistor, and the second terminal is grounded.

[0025] In a preferred embodiment, the application module further includes a constant voltage diode, wherein the first terminal of the constant voltage diode is connected to the second terminal of the third resistor and the second terminal is connected to the second terminal of the fourth resistor.

[0026] In a preferred embodiment, the preset threshold value is the output value of the active derivative module when the rate of change of the oscillation voltage is zero.

[0027] In a preferred embodiment, the controller is configured to adjust the oscillation frequency of the serial LC oscillator or serial LCC oscillator so that the oscillation frequency of the serial LC oscillator or serial LCC oscillator is equal to or approximates a preset frequency.

[0028] Another embodiment of the present application is,

[0029] A susceptor configured to heat an aerosol generating product by passing through a variable magnetic field and generating heat;

[0030] A control method for an aerosol generating device comprising: a series LC oscillator or a series LCC oscillator having an induction coil configured to drive a variable current to pass through the induction coil so as to generate a variable magnetic field in the induction coil;

[0031] A step of detecting the rate of change of the oscillation voltage of the above-mentioned series LC oscillator or series LCC oscillator;

[0032] A step of generating a high-level signal when the rate of change of the above oscillation voltage is greater than a preset value; and

[0033] A method for controlling an aerosol generating device is further provided, comprising the step of determining the oscillation frequency of the LCC oscillator or the serial LC oscillator according to the interval time of the high-level signal.

[0034] In a preferred embodiment,

[0035] The method further includes the step of adjusting the oscillation frequency of the serial LC oscillator or serial LCC oscillator so that the oscillation frequency of the serial LC oscillator or serial LCC oscillator is equal to or approximates a preset frequency. Brief explanation of the drawing

[0036] One or more embodiments are illustrated by way of example with reference to the corresponding accompanying drawings, and such exemplary description is not to limit the embodiments, and unless specifically noted, components with the same reference numeral in the drawings represent similar components, and the accompanying drawings are not limited in scale. FIG. 1 is a schematic diagram of an aerosol generating device according to one embodiment of the present application. Figure 2 is a structural block diagram of one embodiment of the circuit illustrated in Figure 1. FIG. 3 is a schematic diagram of a basic assembly of one embodiment of the circuit shown in FIG. 2. Figure 4 is a schematic diagram of the forward current in one stage of the LCC oscillator shown in Figure 3. Figure 5 is a schematic diagram of the reverse current in one stage of the LCC oscillator shown in Figure 3. Figure 6 is a schematic diagram of the resonant current of the series LCC oscillator shown in Figure 3. Figure 7 is a schematic diagram of the resonant current and resonant voltage changes tested in the series LCC oscillator shown in Figure 3. Figure 8 is a schematic diagram illustrating the change in the signal at the third stage of the active differentiation unit. FIG. 9 is a schematic diagram of a control method for an aerosol generating device according to one embodiment. Specific details for implementing the invention

[0037] To facilitate understanding of the present application, the present application will be described in more detail below with reference to the attached drawings and specific embodiments.

[0038] One embodiment of the present application proposes an aerosol generating device, and with reference to FIG. 1, the structure thereof is,

[0039] A chamber in which an aerosol generating product (A) is removablely accommodated;

[0040] Induction coil (L) that generates a variable magnetic field in AC current;

[0041] A susceptor (30) configured such that at least a portion of it extends within a chamber and is inductively coupled with an induction coil (L) to generate heat as it passes through by a variable magnetic field, and further heats an aerosol generating product (A) such as a coil to volatilize at least one component of the aerosol generating product (A) to form an inhalable aerosol;

[0042] A battery cell (10) which is a secondary DC battery cell capable of outputting DC current; and

[0043] It includes a circuit (20) that is connected to a secondary battery cell (10) via an appropriate electrical connection and converts the DC current output from the battery cell (10) into an AC current of an appropriate frequency and supplies it to an induction coil (L).

[0044] Depending on the usage settings of the product, the induction coil (L) may include a spirally wound cylindrical induction coil as shown in FIG. 1. The spirally wound cylindrical induction coil (L) may have a radius (r) in the range of about 5 mm to 10 mm, and in particular, the radius (r) may be about 7 mm. The length of the spirally wound cylindrical induction coil (L) may be in the range of about 8 mm to 14 mm, and the number of turns of the induction coil (L) may be about 8 turns to 15 turns. Accordingly, the internal volume may be in the range of about 0.15 cm³ to 1.10 cm³.

[0045] In a more preferred embodiment, the frequency of the AC current supplied to the induction coil (L) by the circuit (20) is in the range of 80 KHz to 400 KHz, and more specifically, the frequency may be in the range of about 200 KHz to 300 KHz.

[0046] In a preferred embodiment, the DC power voltage provided by the battery cell (10) is in the range of about 2.5 V to 9.0 V, and the amperage of the DC current that can be provided by the battery cell (10) is in the range of about 2.5 A to 20 A.

[0047] In a preferred embodiment, the susceptor (30) is generally in the shape of a pin or blade that is advantageous for insertion into an aerosol generating product (A), and together the susceptor (30) may be made of grade 430 stainless steel (SS430) with a length of about 12 mm, a width of about 4 mm, and a thickness of 0.5 mm. As an alternative embodiment, the susceptor (30) may be made of grade 430 stainless steel (SS430) with a length of about 12 mm, a width of about 5 mm, and a thickness of 0.5 mm. In another variant embodiment, the susceptor (30) may also be configured in a cylindrical or tubular shape, and when in use, its internal space becomes a chamber for receiving the aerosol generating product (A) and generates an inhalable aerosol by heating the outer circumference of the aerosol generating product (A). These susceptors may also be made of grade 420 stainless steel (SS420) and iron / nickel alloy materials (e.g., permalloy).

[0048] In the embodiment illustrated in FIG. 1, the aerosol generating device further includes a bracket (40) on which an induction coil (L) and a sensor (30) are placed, and the material of the bracket (40) may include a non-metallic material resistant to high temperatures such as PEEK or ceramic. In the embodiment, the induction coil (L) is wound and fixed to the outer wall of the bracket (40). In addition, the bracket (40) is in the shape of a hollow tube as illustrated in FIG. 1, and a portion of the hollow space of the tube becomes the chamber for receiving the aerosol generating product (A).

[0049] In an optional embodiment, the susceptor (30) is made of the magnetizing material described above, or is obtained by forming a magnetizing material coating on the outer surface of a heat-resistant substrate, such as ceramic, through electroplating, deposition, etc.

[0050] In a preferred embodiment, as shown in FIGS. 2 and 3, the structure and basic components of the circuit (20) are,

[0051] An LCC oscillator (24) composed of the above-mentioned induction coil (L), a first capacitor (C1), and a second capacitor (C2), which generates an alternating magnetic field in the induction coil (L) by forming an AC current flowing through the induction coil (L) during the oscillation process, thereby inducing the susceptor (30) to heat up;

[0052] A half-bridge circuit composed of transistor switches, comprising a half-bridge (23) including a switching transistor (Q1) and a switching transistor (Q2) that alternately generate an LCC oscillator (24) by turning on / off switching; and

[0053] It includes a half-bridge driver (22) that controls the switching transistor (Q1) and the switching transistor (Q2) of the half-bridge (23) to turn on / off alternately according to a control signal of the MCU controller (21).

[0054] The overall connection method and detailed oscillation process of the LCC oscillator (24) according to the above embodiment are, specifically, with reference to FIG. 3.

[0055] In the connection, the first capacitor (C1) has its first terminal connected to the positive terminal of the battery cell (10), its second terminal connected to the first terminal of the second capacitor (C2), and the second capacitor (C2) has its second terminal grounded through a resistor (R1).

[0056] The switching transistor (Q1) of the half-bridge (23) has its first terminal connected to the positive terminal of the battery cell (10) and its second terminal connected to the first terminal of the switching transistor (Q2), and the switching transistor (Q2) has its second terminal grounded through a resistor (R1). Of course, the control terminals of both the switching transistor (Q1) and the switching transistor (Q2) are connected to the half-bridge driver (22), and furthermore, they are turned on / off according to the driving of the half-bridge driver (22).

[0057] The induction coil (L) has its first terminal connected to the second terminal of the switching transistor (Q1) and its second terminal connected to the second terminal of the first capacitor (C1). In addition, in the hardware selection of the LCC oscillator (24), the maximum voltage values ​​of the first capacitor (C1) and the second capacitor (C2) are much greater than the output voltage value of the battery cell (10). For example, the output voltage of the battery cell (10) used in a typical embodiment is basically about 4 V, and the maximum voltage of the first capacitor (C1) and the second capacitor (C2) used is 30 V to 80 V.

[0058] In the LCC oscillator (24) with the above structure, when the switching transistor (Q1) and the switching transistor (Q2) are switched, the connection state of the first capacitor (C1) and the second capacitor (C2) with the induction coil (L) is also changed. Specifically, in FIG. 3, when the switching transistor (Q1) is turned on and the switching transistor (Q2) is turned off, the first capacitor (C1) and the inductance coil (L) together form a closed series LC loop, and the second capacitor (C2) and the induction coil (L) form a series LC loop with both ends connected to the positive and negative electrodes of the battery cell (10), respectively. When the switching transistor (Q1) is turned off and the switching transistor (Q2) is turned on, the formed loop is the opposite of the above state, where the first capacitor (C1) and the induction coil (L) form a series LC loop with both ends connected to the positive and negative electrodes of the battery cell (10), respectively, and the second capacitor (C2) and the induction coil (L) together form a closed series LC loop. In each different state, both the first capacitor (C1) and the second capacitor (C2) can form respective LC loops with the induction coil (L). However, the direction and period of the current generated in the oscillation process of each of these LC loops are the same, and furthermore, they together form an AC current flowing through the induction coil (L).

[0059] The specific control steps for the oscillation process using the above LCC oscillator (24) differ from those of conventional series or parallel LC oscillators. Additionally, in a preferred embodiment of the present application, the overall oscillation process of the LCC oscillator (24) is described through the switching operation of the switching transistor (Q1) and the switching transistor (Q2), and specifically includes the following steps.

[0060] Step (S10): The switching transistor (Q1) is turned on and the switching transistor (Q2) is kept in the turned-off state, and in this state, the LCC oscillator (24) performs the following two processes. Specifically,

[0061] Step (S11): As illustrated in FIG. 4, when the switching transistor (Q1) is turned on and the switching transistor (Q2) is turned off, the battery cell (10) charges the second capacitor (C2) by the current (i1) while the first capacitor (C1) is discharged by the current (i2). During this process, as illustrated in FIG. 4, a current flowing from left to right through the induction coil (L) is formed, which can be recorded as a forward current. In Step (S11), the first capacitor (C1) starts discharging when turned on by the switching transistor (Q1) and is completed until the voltage difference between the two ends becomes zero. Then, charging is stopped until the voltage between the two ends of the second capacitor (C2) increases to equal the output voltage of the battery cell (10), at which time the current in the induction coil (L) reaches the maximum resonance peak value.

[0062] Step (S12): After completing Step (S11), if the switching transistor (Q1) is kept in the turned-on state and the switching transistor (Q2) is kept in the turned-off state, the induction coil (L) is discharged in the same direction as the current (i2) in Fig. 1 and charges the first capacitor (C1), so that the current flowing in the forward direction through the induction coil (L) gradually decreases until the current of the induction coil (L) is discharged to zero. In the above step, since the first capacitor (C1) is completely discharged in Step (S11), the loop formed between the induction coil (L) and the first capacitor (C1) through the switching transistor (Q1) has almost no impedance. Therefore, in Step (S12), the induction coil (L) mainly discharges to charge the first capacitor (C1), and the current flowing through the induction coil (L) during the discharge process is the same as the current (i2) in Step (S11). The second capacitor (C2) is basically charged to be equal to the output voltage of the battery cell (10) in step (S11), and in step (S12), the induction coil (L) compensates for the second capacitor (C2) by a very small amount, but it is almost negligible.

[0063] Throughout the entire process of steps (S11) and (S12), the sum of the currents flowing through the induction coil (L) increases from 0 to a maximum in the forward direction, and then the discharge of the induction coil (L) gradually decreases to 0, and the direction of the currents flowing through the induction coil (L) is always in the forward direction from left to right.

[0064] Step (S20): After Step (S10) is completed, the switching transistor (Q1) is turned off and the switching transistor (Q2) is turned on to perform the process of the following two steps. Specifically,

[0065] Step (S21): The switching transistor (Q2) starts to turn on and creates a loop of currents (i3) and (i4) shown in FIG. 5 in the LCC oscillator (24). According to the current path shown in FIG. 5, current (i3) sequentially passes from the positive terminal of the battery cell (10) through the first capacitor (C1), the induction coil (L), and the switching transistor (Q2), and then returns to the negative terminal of the battery cell (10) through ground to form a loop, and at the same time, current (i4) sequentially passes from the positive terminal of the second capacitor (C2) through the induction coil (L) and the switching transistor (Q2) in a counterclockwise direction, and then returns to the negative terminal of the second capacitor (C2) to form a loop. In the above process, as shown in FIG. 5, a current flowing from right to left through the induction coil (L) is formed, which is opposite to the current direction of FIG. 4 and can be recorded as a reverse current.

[0066] Step (S21) includes charging the first capacitor (C1) and discharging the second capacitor (C2) simultaneously, increasing the voltage of the first capacitor (C1) until it is equal to the output voltage of the battery cell (10), and when the voltage difference across the second capacitor (C2) becomes zero, the current of the induction coil (L) reaches a maximum resonance peak value.

[0067] Step (S22): After Step (S21) is completed, if the switching transistor (Q2) is kept in the turned-on state, the induction coil (L) reverse-charges the second capacitor (C2), so that the current flowing in the reverse direction through the induction coil (L) gradually decreases until the current of the induction coil (L) is discharged to zero.

[0068] In the entire process of steps (S21) and (S22) of the above step (S20), the sum of the currents flowing through the induction coil (L) increases in the reverse direction from 0 to a maximum, and then the discharge of the induction coil (L) gradually decreases to 0.

[0069] Accordingly, during the process of the LCC oscillator (24) oscillating, the change in current flowing through the induction coil (L) can be seen by referring to FIG. 6, and one complete current cycle includes four parts corresponding to steps (S11), (S12), (S21), and (S22) of FIG. 6, respectively. Steps (S10) and (S20) can form an AC current flowing through the induction coil (L) by circulating and alternately switching the turn-on / turn-off states of the switching transistor (Q1) and the switching transistor (Q2), thereby circulating the oscillation process of steps (S11), (S12), (S21), and (S22) in the LCC oscillator (24).

[0070] Therefore, based on the above control process, it can be seen that the LCC oscillator (24) of the present application generates inversion with a ZCS (zero current switch) inverter topology, unlike the ZVS (Zero Voltage Switch) inverter topology of a conventional LC oscillator, and that the switching transistor (Q1) and the switching transistor (Q2) are configured to switch on / off when the current flowing through the induction coil (L) is zero.

[0071] In the preferred embodiment illustrated in FIG. 3, the number of the first capacitor (C1) and the second capacitor is one. In other optional embodiments, the first capacitor (C1) or the second capacitor (C2) may each be configured to include two or three capacitors connected in parallel with each other and having a small relative capacitance. For example, when the first capacitor (C1) is replaced with a plurality of small capacitors to replace the originally required relatively large capacitor, since their capacitances are the same or nearly the same, the ESR (equivalent resistance value) between each capacitor may be significantly reduced and change compared to the case where only a single capacitor is used, depending on the change in the oscillation frequency of the LCC oscillator (24). Specifically, since the ESR appears relatively high at low frequencies and relatively low at high frequencies, it may help prevent spikes. Also, when using a plurality of small capacitors to replace the originally required relatively large capacitor, it is advantageous to lower the resonance frequency of the LCC oscillator (24).

[0072] The circuit (20) using the above LCC oscillator (24) forms an inverting by ZCS technology in the embodiment and has a resonant frequency that is about half that of the current LC series / parallel oscillation of a single capacitor. Generally, when the LC series / parallel oscillation frequency is about 380 Hz, the oscillation frequency of the above LCC oscillator (24) is about 190 Hz, which is advantageous for both synchronization detection and control of the MCU controller (21).

[0073] The changes in the resonant voltage and current of the LCC oscillator (24) detected during the above oscillation process are shown in FIG. 7, where the resonant voltage leads the resonant current by about 1 / 4 cycle, and the entire LCC oscillator (24) exhibits weak induction. "Capacitive" and "inductive" are electrical terms related to the hybrid circuit of an electronic device (e.g., an LC oscillator or the LCC oscillator (24)). When the capacitive reactance of the hybrid circuit is greater than the inductive reactance, the circuit exhibits "capacitiveness," and when the inductive reactance is greater than the capacitive reactance, the circuit exhibits inductiveness. The state of "weak induction" is basically a state where the inductive reactance is close to the capacitive reactance and the inductive reactance is slightly greater than the capacitive reactance.

[0074] Additionally, referring to the embodiment illustrated in FIG. 3, the half-bridge driver (22) is a switching transistor driver of the commonly used FD2204 model, which is controlled by the MCU controller (21) in PWM mode, and the third and tenth I / O ports each alternately transmit high level / low level according to the pulse width of the PWM to drive the turn-on time of the switching transistor (Q1) and the switching transistor (Q2) to control the oscillation of the LCC oscillator (24).

[0075] In the above detailed control step, the LCC inverting process is symmetric, and the corresponding MCU controller (21) can transmit a PWM control signal with a duty cycle of 50% to the half-bridge driver (22) to drive the half-bridge (23) and switch in this way.

[0076] Additionally, referring to FIG. 2, in order to accurately detect the oscillation frequency of the LCC oscillator (24), the circuit (20) further includes an active differentiation unit (25), and the detection process by the active differentiation unit (25) is,

[0077] Based on the characteristic that the current becomes zero as the oscillation voltage gradually reaches a maximum, the rate of change / derivative of the oscillation voltage of the LCC oscillator (24) is first detected, and

[0078] And the rate of change or derivative of the voltage is compared with a preset threshold value, and when it is greater than the preset threshold value, a pulse-type interrupt signal is output to the MCU controller (21).

[0079] The MCU controller (21) can obtain the oscillation frequency of the LCC oscillator (24) according to the time interval of the received interrupt signal.

[0080] A specific embodiment of the above process is carried out by three submodules of the active differential unit (25) shown in FIG. 3, specifically,

[0081] The signal application module is composed of a diode (D1), a resistor (R2), a resistor (R3), and a voltage regulator diode (Z). The diode (D1) filters out a negative half-wave voltage while allowing a positive half-wave voltage to be applied to the LCC oscillator (24), and is then divided by the resistors (R2) and (R3). The voltage regulator diode Z prevents excessive input voltage and protects the downstream circuit.

[0082] The active differentiation module is a general active differentiation circuit equipped with standard basic components in FIG. 3, and is composed of an operational amplifier (U1), a capacitor (C3), a resistor (R4), a resistor (R5), a resistor (R6), and a capacitor (C4) and a resistor (R7). The operational amplifier (U1), the capacitor (C3), and the resistor (R4) are basic components required to form the active differentiation module, and the ratio of the resistor (R4) to the resistor (R7) is 1. This is intended to avoid high peaks at the output so that the circuit has the flattest amplitude-frequency response and to reduce the Q value, and the capacitor (C4) is intended for voltage stabilization to prevent self-excitation oscillation of the operational amplifier.

[0083] The voltage signal (Vout) output by the active derivative module during operation is

[0084] In the formula, PP_LCC is the resonant voltage of the LCC oscillator (24), and according to the principle of this calculation formula, the output result is the result of a comprehensive calculation of the relevant element parameters in the derivative and active derivative of the resonant voltage of the LCC oscillator (24) with respect to time t, and since the parameters of the relevant element are known and given in advance, the output result may be equivalent to the derivative of the voltage with respect to time, that is, the rate of change of the voltage.

[0085] The comparison output module is mainly a comparator (U2) in FIG. 3, and outputs a high level when the Vout output of the active derivative module is higher than a preset threshold.

[0086] To facilitate the understanding of the technician, FIG. 8 is a schematic diagram of the three-stage signal change of the active differential unit (25) detected in one embodiment,

[0087] Signal 1 is a graph of the voltage signal at a point between resistors (R2) and (R3) of the signal application module, and

[0088] Signal 2 is a graph of the voltage signal (Vout) output by the operational amplifier (U1) of the active differentiation module, and

[0089] Signal 3 is a graph of a pulsed square wave that is compared and output by the comparator (U2).

[0090] According to the calculation formula for the output voltage signal (Vout) above, signal 2 in FIG. 8 is in a positive correlation with signal 1; that is, while signal 1 is rising, signal 2 is output as a negative value, signal 2 becomes 0 until signal 1 reaches a peak, and signal 2 is output as a positive value when signal 1 begins to fall from the peak. However, it should be noted that since the active derivative module cannot output a negative signal, a reference value is added to the calculation result so that the output of signal 2 is always positive. The comparator (U2) uses the reference value as a comparison standard, and if signal 2 is higher than the reference value and continues to increase, it means that signal 1 is in the process of falling from the peak value, and outputs a low level after the fall ends. According to the above description, the formula adopts the signal value output when signal 1 reaches a peak, that is, when the rate of change of voltage is 0, as the reference value of the reference input terminal of the comparator (U2), i.e., R6*2.5 / (R5+R6).

[0091] As described above, in the embodiment, the MCU controller (21) does not need to actively perform high-frequency sampling to obtain the oscillation frequency of the LCC oscillator (24), and only needs to transmit the pulsed square wave of signal 3 to the MCU controller (21) as an interrupt signal, and the MCU controller (21) calculates the frequency by calculating the interval time (i.e., period) between adjacent square waves after receiving the signal. Here, the electrical term "interrupt signal" is a control method for a device such as a chip or a single-chip microcomputer, and specifically, when the CPU or receiving process receives the "interrupt signal," it temporarily suspends another process or task, performs the function or process corresponding to the "interrupt signal" at an appropriate time, and then returns to the original process or task.

[0092] By the above method, the active derivative module (25) detects the voltage change rate or derivative of the LCC oscillator (24), performs a comparison operation to generate a square wave of the same frequency, and transmits the square wave as an interrupt signal to the MCU controller (21). Upon receiving the signal, the MCU controller (21) calculates the interval time (i.e., period) between adjacent square waves to calculate the frequency.

[0093] In another variant embodiment, the LCC oscillator (24) may replace or be used as a series LC oscillator having the same symmetric resonance, their oscillation process is performed with a duty cycle of 50% and outputs a symmetric sine or cosine changing voltage or current, and their switching is performed by zero current topology technology. An active differential unit (25) may be used to track the frequency of the series LC oscillator to facilitate control and regulation.

[0094] Another embodiment of the present application further proposes a method for controlling an aerosol generating device that drives a receptor (30) to heat using the aforementioned LCC oscillator (24) or a similar serial LC oscillator. As illustrated in FIG. 9, the method

[0095] A step (S100) of detecting the rate of change of the oscillation voltage of a series LC oscillator (24) or a series LCC oscillator;

[0096] A step (S200) of comparing the rate of change of the oscillation voltage with a preset value and generating a high-level signal if it is greater than the preset value;

[0097] A step (S300) of calculating the oscillation frequency of an LCC oscillator or a serial LC oscillator by detecting the interval time of a high-level signal; and

[0098] It includes a step (S400) in which the oscillation frequency of the LCC oscillator (24) or the serial LC oscillator can be additionally adjusted by the MCU controller (21) to be equal to or close to a preset frequency.

[0099] By tracking, detecting, and adjusting the frequency in real time, the oscillation frequency is maintained at or close to the preset frequency, and furthermore, efficiency is maximized.

[0100] Although preferred embodiments of the present application are described in the specification and accompanying drawings, it should be noted that the present application is not limited to the embodiments described in the specification, and that those skilled in the art may make improvements or modifications based on the above description, and all such improvements and modifications must fall within the scope of protection of the appended claims of the present application.

Claims

Claim 1 An aerosol generating device configured to generate an inhalable aerosol by heating an aerosol generating product, comprising: a susceptor configured to heat the aerosol generating product by passing through a variable magnetic field and generating heat; a series LC oscillator or series LCC oscillator having an induction coil configured to drive a variable current to pass through the induction coil so as to generate a variable magnetic field in the induction coil; and a circuit configured to determine the oscillation frequency of the series LC oscillator or series LCC oscillator according to the time interval of two first jumps of the rate of change of the oscillation voltage of the series LC oscillator or series LCC oscillator; wherein the first jump indicates a change from a state smaller than a preset threshold to a state larger than a preset threshold. Claim 2 The aerosol generating device according to claim 1, wherein the circuit comprises: an active differentiation unit configured to detect the rate of change of the oscillation voltage of the serial LC oscillator or serial LCC oscillator and output a high-level signal when the rate of change of the oscillation voltage is greater than a preset threshold; and a controller configured to determine the oscillation frequency of the serial LC oscillator or serial LCC oscillator according to the interval time of the high-level signal. Claim 3 In paragraph 2, the aerosol generating device comprises: an active differentiation unit configured to detect the rate of change of the oscillation voltage of the serial LC oscillator or serial LCC oscillator; and a comparator configured to compare the rate of change of the oscillation voltage with a preset threshold value and output a high-level signal to the controller when the rate of change of the oscillation voltage is greater than the preset threshold value. Claim 4 In paragraph 3, the active differential module comprises a first capacitor, a first resistor, a second capacitor, a second resistor, and an operational amplifier, wherein the first capacitor has a first terminal connected to the series LC oscillator or series LCC oscillator and a second terminal connected to the first terminal of the first resistor, the operational amplifier has a first input terminal connected to the second terminal of the first resistor and an output terminal connected to the comparator, the second capacitor has a first terminal connected to the second terminal of the first resistor and a second terminal connected to the output terminal of the operational amplifier, and the second resistor has a first terminal connected to the second terminal of the first resistor and a second terminal connected to the output terminal of the operational amplifier, an aerosol generating device. Claim 5 In paragraph 3, the active differential unit further comprises an application module including a first diode, a third resistor, and a fourth resistor, wherein the first diode has a first terminal connected to the series LC oscillator or series LCC oscillator and a second terminal connected to the first terminal of the third resistor, and is configured to allow current to flow only from the series LC oscillator or series LCC oscillator to the third resistor, the third resistor has a second terminal connected to the active differential module, and the fourth resistor has a first terminal connected to the second terminal of the third resistor and a second terminal grounded, an aerosol generating device. Claim 6 In claim 5, the above-mentioned application module further comprises a constant voltage diode, wherein the constant voltage diode has a first terminal connected to the second terminal of the third resistor and a second terminal connected to the second terminal of the fourth resistor, an aerosol generating device. Claim 7 An aerosol generating device according to any one of claims 3 to 6, wherein the preset threshold value is the output value of the active differential module when the rate of change of the oscillation voltage is 0. Claim 8 An aerosol generating device according to any one of claims 2 to 6, wherein the controller is configured to adjust the oscillation frequency of the serial LC oscillator or serial LCC oscillator so that the oscillation frequency of the serial LC oscillator or serial LCC oscillator is equal to or approximates a preset frequency. Claim 9 A method for controlling an aerosol generating device comprising: a susceptor configured to heat an aerosol generating product by generating heat while passing through a variable magnetic field; and a series LC oscillator or series LCC oscillator having an induction coil configured to drive a variable current to flow through an induction coil to generate a variable magnetic field in the induction coil, the method comprising: a step of detecting a rate of change of the oscillation voltage of the series LC oscillator or series LCC oscillator; a step of generating a high-level signal when the rate of change of the oscillation voltage is greater than a preset value; and a step of determining the oscillation frequency of the LCC oscillator or series LC oscillator according to the interval time of the high-level signal. Claim 10 A method for controlling an aerosol generating device, further comprising the step of adjusting the oscillation frequency of the serial LC oscillator or the serial LCC oscillator so that the oscillation frequency of the serial LC oscillator or the serial LCC oscillator is equal to or approximates a preset frequency in claim 9.

Images