Aerosol generating device and control method thereof

Abstract

The invention provides an aerosol generating device and a control method thereof. The aerosol generating device comprises a power supply circuit; the DC / AC inverter comprises an E-type power amplifier, and the E-type power amplifier comprises a transistor switch and an LC load network formed by a capacitor and an inductor; an inductor inductively coupled to the susceptor, thereby heating the aerosol-forming substrate to generate an aerosol; a controller configured to, in operation, determine an apparent ohmic resistance based on the DC supply voltage and a DC current output to the DC / AC inverter by the power supply circuit; the controller is further configured to monitor a change in the apparent ohmic resistance and adjust a frequency and a duty cycle of a switching signal supplied to the transistor switch when the apparent ohmic resistance changes. According to the aerosol generating device and the control method thereof, the frequency and the duty ratio of the switching signal supplied to the transistor switch are adjusted by monitoring the change of the apparent ohmic resistance and when the apparent ohmic resistance changes; therefore, the E-type power amplifier always works in the optimal state.

Description

Technical Field

[0001] The present application relates to the technical field of electronic atomization, and particularly to an aerosol generating device and a control method thereof. Background Art

[0002] An existing aerosol generating device uses a class E power amplifier, which enables an inductor to generate a changing magnetic field, and then enables a receptor to heat an aerosol to form a matrix. The class E power amplifier has the characteristics of high operating frequency and high efficiency, and uses a small number of components, which can reduce the volume of the product. However, when the load size fluctuates, the working waveform of the transistor switch changes drastically, resulting in its inability to work in an ideal state in real time, which greatly reduces its application range. Summary of the Invention

[0003] The present application provides an aerosol generating device and a control method thereof to provide a real-time variable zero position for a class E power amplifier in a situation where the load is variable, so that it can work in an ideal state in real time.

[0004] Based on the above technical problems, on the one hand, the present application provides an aerosol generating device, including:

[0005] A power supply circuit for providing a DC supply voltage;

[0006] A DC / AC inverter connected to the power supply circuit; the DC / AC inverter includes a class E power amplifier, and the class E power amplifier includes a transistor switch and an LC load network composed of a capacitor and an inductor; wherein, the inductor is inductively coupled to a receptor to heat an aerosol to form a matrix to generate an aerosol;

[0007] A controller configured to determine an apparent ohmic resistance based on the DC supply voltage and the DC current output from the power supply circuit to the DC / AC inverter during operation; the controller is further configured to monitor the change of the apparent ohmic resistance, and when the apparent ohmic resistance changes, adjust the frequency and duty cycle of the switching signal supplied to the transistor switch.

[0008] On the other hand, the present application provides a control method for an aerosol generating device, and the aerosol generating device includes:

[0009] A power supply circuit for providing a DC supply voltage;

[0010] A DC / AC inverter connected to the power supply circuit; the DC / AC inverter includes a class E power amplifier, and the class E power amplifier includes a transistor switch and an LC load network composed of a capacitor and an inductor; wherein, the inductor is inductively coupled to a receptor to heat an aerosol to form a matrix to generate an aerosol;

[0011] The method includes:

[0012] Determining an apparent ohmic resistance based on the DC supply voltage and the DC current output from the power supply circuit to the DC / AC inverter during operation;

[0013] Monitoring the change of the apparent ohmic resistance, and when the apparent ohmic resistance changes, adjusting the frequency and duty cycle of the switching signal supplied to the transistor switch.

[0014] The above aerosol generating device and its control method monitor the change of the apparent ohmic resistance, and when the apparent ohmic resistance changes, adjust the frequency and duty cycle of the switching signal supplied to the transistor switch; thereby enabling the class-E power amplifier to always operate in the best state, that is, the drain voltage of the transistor switch satisfies the zero-voltage turn-on and zero-voltage derivative turn-on conditions, improving the efficiency of the whole machine. Brief Description of the Drawings

[0015] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, the drawings in the figures do not constitute a proportional limitation.

[0016] Figure 1 It is a schematic diagram of an aerosol generating device provided by an embodiment of the present application;

[0017] Figure 2 It is a schematic diagram of another aerosol generating device provided by an embodiment of the present application;

[0018] Figure 3 It is a schematic diagram of the circuit of a class-E power amplifier provided by an embodiment of the present application;

[0019] Figure 4 It is a schematic diagram of a current detection circuit provided by an embodiment of the present application;

[0020] Figure 5 It is a schematic diagram of a power supply circuit provided by an embodiment of the present application;

[0021] Figure 6 It is a schematic diagram of the waveforms of the gate voltage, drain voltage and current of a transistor switch provided by an embodiment of the present application;

[0022] Figure 7 It is a schematic diagram of the waveforms of the gate voltage and drain voltage of a transistor switch under an apparent ohmic resistance provided by an embodiment of the present application;

[0023] Figure 8It is a schematic waveform diagram of the gate voltage and drain voltage of a transistor switch under another apparent ohmic resistance provided by an embodiment of the present application;

[0024] Figure 9 It is another schematic waveform diagram of the gate voltage and drain voltage of a transistor switch under another apparent ohmic resistance provided by an embodiment of the present application;

[0025] Figure 10 It is a schematic waveform diagram of the gate voltage and drain voltage of a transistor switch under a power supply voltage provided by an embodiment of the present application;

[0026] Figure 11 It is a schematic waveform diagram of the gate voltage and drain voltage of a transistor switch under another power supply voltage provided by an embodiment of the present application;

[0027] Figure 12 It is a schematic curve diagram of the temperature and time of a sensor provided by an embodiment of the present application;

[0028] Figure 13 It is a schematic flowchart of a control method for an aerosol generating device provided by an embodiment of the present application. Detailed implementation manners

[0029] For the convenience of understanding the present application, the present application will be described in more detail below in conjunction with the accompanying drawings and specific implementation manners. It should be noted that when an element is expressed as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is expressed as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "upper", "lower", "left", "right", "inner", "outer" and similar expressions used in this specification are only for the purpose of illustration.

[0030] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in this specification in the description of the present application are only for the purpose of describing specific implementation manners and are not used to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0031] Figure 1 It is a schematic diagram of an aerosol generating device provided by an embodiment of the present application.

[0032] As Figure 1 shown, the aerosol generating device includes an atomizer 10 and a power supply assembly 20.

[0033] In one example, the atomizer 10 is removably connected to the power supply assembly 20, and the atomizer 10 and the power supply assembly 20 can be connected by snap fit, magnetic connection, etc. In another example, it is also feasible that the atomizer 10 and the power supply assembly 20 are integrally formed.

[0034] The atomizer 10 includes a carrier or container for holding a liquid aerosol-forming substrate, and the susceptor 11 can be incorporated within the carrier or container. For example, the container for holding the liquid aerosol-forming substrate has a liquid storage cavity, and the susceptor 11 is installed within the container; the position of the susceptor 11 within the container is fixed, which is conducive to generating a more efficient coupling with the inductor 21 when the atomizer 10 cooperates with the power supply assembly 20.

[0035] The susceptor 11 is configured to couple with the inductor 21 and heat up when penetrated by a changing magnetic field, thereby heating the liquid aerosol-forming substrate and causing at least one component of the liquid aerosol-forming substrate to volatilize to form an aerosol for inhalation.

[0036] The susceptor 11 can be in direct contact with the liquid aerosol-forming substrate within the liquid storage cavity, or the susceptor 11 can be in indirect contact with the liquid aerosol-forming substrate. For example, a wicking material is provided between the susceptor 11 and the liquid storage cavity, and the wicking material is used to transfer the liquid aerosol-forming substrate to the susceptor 11. Optional wicking materials include porous materials or fibrous materials.

[0037] The susceptor 11 can be made of at least one of the following materials: aluminum, iron, nickel, copper, bronze, cobalt, plain carbon steel, stainless steel, ferritic stainless steel, martensitic stainless steel, or austenitic stainless steel.

[0038] The power supply assembly 20 includes an inductor 21, a circuit 22, and an electric cell 23.

[0039] The inductor 21 generates a changing magnetic field under an alternating current, and the inductor 21 includes, but is not limited to, an induction coil.

[0040] The circuit 22 can control the overall operation of the aerosol generating device. The circuit 22 not only controls the operation of the electric cell 23 and the inductor 21, but also controls the operation of other components in the aerosol generating device.

[0041] The electric cell 23 provides power for operating the aerosol generating device. The electric cell 23 can be a rechargeable electric cell or a disposable electric cell.

[0042] Figure 2 It is a schematic diagram of an aerosol generating device provided by another embodiment of the present application.

[0043] As Figure 2 shown, the aerosol generating device includes:

[0044] A chamber, in which a solid aerosol-forming substrate is removably received; the solid aerosol-forming substrate can be a part of an aerosol-generating article A, such as a cigarette.

[0045] A sensor 110, at least a part of which extends into the chamber and is configured to be coupled to an inductor 210, generates heat when penetrated by a changing magnetic field, and then heats the solid aerosol-forming substrate to volatilize at least one component of the solid aerosol-forming substrate to form an aerosol for inhalation.

[0046] In one example, the sensor 110 is generally in the shape of a pin or a blade, which is beneficial for insertion into the solid aerosol-forming substrate; at the same time, the sensor 110 can have a length of about 12 mm, a width of about 4 mm and a thickness of about 0.5 mm, and can be made of stainless steel grade 430 (SS430). As an alternative embodiment, the sensor 110 can have a length of about 12 mm, a width of about 5 mm and a thickness of about 0.5 mm, and can be made of stainless steel grade 430 (SS430).

[0047] In another example, the sensor 110 can also be configured in a cylindrical or tubular shape; during use, its internal space forms a chamber for receiving the solid aerosol-forming substrate, and an aerosol for inhalation is generated by heating the outer periphery of the solid aerosol-forming substrate. These sensors can also be made of stainless steel grade 420 (SS420) and an iron / nickel-containing alloy material (such as permalloy).

[0048] An inductor 210, which is used to generate a changing magnetic field under an alternating current; according to the settings during product use, the inductor 210 can include a cylindrical inductor coil wound in a spiral shape.

[0049] A circuit 220, electrically connected to a battery cell 230, is used to convert the direct current output from the battery cell 230 into an alternating current with a suitable frequency and then supply it to the inductor 210.

[0050] A battery cell 230, which provides power for operating the aerosol-generating device. The battery cell 23 can be a rechargeable battery cell or a disposable battery cell.

[0051] Based on the above aerosol-generating device, Figures 3 - 5 A schematic diagram showing the basic components of an embodiment of the circuit is shown.

[0052] As Figure 3As shown, the circuit includes a DC / AC inverter, which is connected to a power supply circuit that provides a DC supply voltage V_DC. In this embodiment, the DC / AC inverter includes a class-E power amplifier, i.e., a resonant switching power amplifier, which includes the following components: a transistor switch Q1, which includes a field-effect transistor, such as a metal-oxide semiconductor field-effect transistor (MOSFET); a transistor switch drive circuit K1, which can supply a switching signal with a certain frequency and duty cycle to the transistor switch Q1 under the control of a controller; and an LC load network including a capacitor C1, a capacitor C2, and an inductor L2. The inductor L2 can correspond to, for example, Figure 1 the inductor 21 shown in Figure 2 or the inductor 210 shown in Figure 1 . In addition, a DC feed choke L1 is provided for supplying the DC supply voltage V_DC from the power supply circuit. Also shown in the figure is an ohmic resistor R representing the total equivalent resistance or total resistive load, which can include, for example, the ohmic resistance of the inductor L2 and the ohmic resistance of the sensor 11 shown in Figure 2 , or the ohmic resistance of the inductor L2 and the ohmic resistance of the sensor 110 shown in

[0053] . The controller can be configured to determine the apparent ohmic resistance (hereinafter represented by Ra) during operation through the DC supply voltage of the power supply circuit and through the DC current drawn from the power supply circuit, i.e., to determine the apparent ohmic resistance based on the DC supply voltage and the DC current output by the power supply circuit to the DC / AC inverter.

[0054] Providing the apparent ohmic resistance Ra can determine the temperature of the sensor, i.e., the apparent ohmic resistance Ra can indicate the temperature of the sensor and thus the temperature of the aerosol-forming substrate. The apparent ohmic resistance Ra can increase with the increase in temperature, or decrease with the increase in temperature; it can also increase first and then decrease or decrease first and then increase with the increase in temperature, which is determined by the material properties of the sensor. For example, when two materials, stainless steel of grade 430 and permalloy material, are laminated and the temperature rises to 250 °C, the value of the apparent ohmic resistance Ra increases, and when heating continues, the value of the apparent ohmic resistance Ra starts to decrease again. Utilizing the Curie temperature characteristic of the ferromagnetic material, non-contact temperature control can be achieved; that is, it is not necessary to directly measure the temperature of the sensor, and only by the magnitude of the current input to the inverter and / or the resonant voltage value of the inverter, the current temperature of the sensor can be judged.

[0055] In actual work, both the DC supply voltage and the DC current drawn from the power supply circuit can be measured to determine the apparent ohmic resistance Ra. When the power supply circuit provides a fixed DC supply voltage, only the DC current drawn from the power supply circuit can also be measured. Figure 4 A current detection circuit is shown for detecting the DC current drawn from the power supply circuit. The current detection circuit mainly includes:

[0056] A voltage detection chip U7 and a sampling resistor R33. One end of the sampling resistor R33 is electrically connected to the power supply circuit, and the other end of the sampling resistor R33 is electrically connected to the DC feed choke L1 (shown as L1_OUT in the figure). The 4th pin of the current detection chip U7 is connected to one end of the sampling resistor R33, the 5th pin of the current detection chip U7 is electrically connected to the other end of the sampling resistor R33, and the 6th pin of the voltage detection chip U7 outputs the voltage across the sampled resistor R33 to the controller (shown as ADC_OUT in the figure). Based on the voltage across the resistor R33 and the resistance value of the resistor R33, the controller can determine the magnitude of the DC current drawn from the power supply circuit. The resistor R12 and the capacitor C19 in the figure form a filter circuit to filter the voltage across the sampled resistor R33.

[0057] Figure 5 A power supply circuit provided by an embodiment of the present application, which can provide a variable DC supply voltage for the class-E power amplifier. As Figure 5 shown, the power supply circuit includes:

[0058] A DC-DC conversion circuit 301 composed of a power supply chip U4 and its peripheral circuits. The power supply chip U4 mainly includes an input terminal (the 8th pin in the figure) electrically connected to the battery cell, an output terminal (the 16th pin in the figure) for outputting the DC supply voltage V_DC, and a feedback terminal (the 4th pin in the figure). The power supply chip U4 can be a boost chip or a buck chip. In this example, a buck chip is used.

[0059] An adjustment circuit 302 composed of a potentiometer U12 and its peripheral circuits. The adjustment circuit 302 is configured to receive the control of the controller, so as to generate an adjustment signal at the feedback terminal of the DC-DC conversion circuit 301, so that the DC-DC conversion circuit 301 responds to the adjustment signal and converts the battery cell voltage BAT_IN into the corresponding DC supply voltage V_DC. Specifically, the potentiometer chip U12 uses the I2C protocol for access and control, and can realize the adjustment of the resistance value connected between the 5th pin and the 6th pin, so as to generate an adjustment signal at the feedback terminal of the DC-DC conversion circuit 301. The magnitude of each level of adjustment is determined by the number of bits of the chip, such as 8-bit / 10 / 12-bit, etc., that is, the maximum resistance value of the potentiometer is divided into 2 8 / 2 10 / 212 。

[0060] Further, it further includes a voltage detection circuit 303 composed of a resistor R28, a resistor R39, and a capacitor C45. The voltage detection circuit 303 is used to detect the current DC supply voltage to determine whether it is the required DC supply voltage. If it is not the required DC supply voltage, the potentiometer chip U12 is controlled until the current DC supply voltage is the required DC supply voltage. Among them, the resistors R28 and R39 form a voltage division circuit, and the capacitor C45 is used to filter the voltage division signal.

[0061] Please refer to Figure 3 As shown, the output power P of the class-E power amplifier is 0.5678×V_DC 2 / R. When the transistor switch Q1 (assumed to be an NMOS transistor) is turned on, if the drain voltage of the transistor switch Q1 exactly reaches the zero axis, the drain voltage of the transistor switch Q1 satisfies the zero-voltage turn-on and zero-voltage derivative turn-on conditions. At this time, the voltage V ds and the current I ds do not overlap, the power consumption of the transistor switch Q1 is 0, and the efficiency of the class-E power amplifier is the highest. In practice, the efficiency of the class-E power amplifier can reach 95%. Specifically, as Figure 6 shown:

[0062] (a) The drain voltage of the transistor switch Q1 satisfies the zero-voltage turn-on and zero-voltage derivative turn-on conditions, and the class-E power amplifier works in the best state. At this time, the value of the ohmic resistor R is appropriate. Ug in the figure is the gate voltage, Vs is the drain voltage, and Is is the drain current.

[0063] (b) When the value of the ohmic resistor R is too large, the output power of the class-E power amplifier is too small, and it works in a quasi-optimal state. The lowest point of the drain voltage of the transistor switch Q1 appears below the zero axis (the horizontal axis in the figure).

[0064] (c) When the value of the ohmic resistor R is too small, the output power of the class-E power amplifier is too high, and it works in a misaligned state. At this time, the drain voltage of the transistor switch Q1 is above the zero axis.

[0065] From the above, it can be seen that the class-E power amplifier has less or almost zero power loss only when it is matched with a load of appropriate size. When the load becomes larger or smaller, the actual efficiency of the class-E power amplifier will be reduced.

[0066] In one example, the controller is configured to monitor the change in the apparent ohmic resistance Ra, and when the apparent ohmic resistance Ra changes, adjust the frequency and duty cycle of the switching signal supplied to the transistor switch Q1. Thereby enabling the class-E power amplifier to always operate in an optimal state, that is, the drain voltage of the transistor switch Q1 satisfies the zero-voltage turn-on and zero-voltage derivative turn-on conditions, improving the efficiency of the entire machine.

[0067] As Figure 7 shown, when the apparent ohmic resistance Ra is 0.6 ohms, the frequency and duty cycle of the switching signal (shown as VG2 in the figure) supplied to the transistor switch Q1 are 6.82 MHz and 50% respectively. At this time, it can be observed that the drain voltage waveform of the transistor switch Q1 is relatively ideal, satisfying the zero-voltage turn-on and zero-voltage derivative turn-on conditions.

[0068] As Figure 8 shown, when the heating temperature rises, the apparent ohmic resistance Ra decreases to 0.5 ohms. If the frequency and duty cycle of the switching signal supplied to the transistor switch Q1 remain unchanged. From Figure 8 it can be observed that the zero point position of the drain voltage of the transistor switch Q1 is -0.9 V, and the transistor switch Q1 does not turn on at this moment. Therefore, the product of the voltage and current across the drain-source of the transistor switch Q1 is much greater than 0, the loss of the transistor switch Q1 is large, the transistor switch Q1 generates a lot of heat, the operating temperature is high, and the efficiency is reduced.

[0069] As Figure 9 shown, if when the apparent ohmic resistance Ra decreases to 0.5 ohms, the frequency and duty cycle of the switching signal supplied to the transistor switch Q1 are adjusted, for example, the frequency and duty cycle of the switching signal supplied to the transistor switch Q1 are adjusted to 6.676 MHz and 53%. From Figure 9 it can be observed that the drain voltage waveform of the transistor switch Q1 satisfies the zero-voltage turn-on and zero-voltage derivative turn-on conditions.

[0070] In one example, the controller is configured to, when monitoring that the apparent ohmic resistance Ra decreases, reduce the frequency of the switching signal of the transistor switch Q1 and increase the duty cycle of the switching signal of the transistor switch Q1; or, when monitoring that the apparent ohmic resistance Ra increases, increase the frequency of the switching signal of the transistor switch Q1 and decrease the duty cycle of the switching signal of the transistor switch Q1.

[0071] In one example, the controller is further configured to, when the apparent ohmic resistance Ra changes, control the power supply circuit to adjust the DC supply voltage. Thereby adjusting the heating power and improving the efficiency of the entire machine.

[0072] In a specific example, the controller is configured to control the power supply circuit to reduce the DC supply voltage when it monitors that the apparent ohmic resistance Ra decreases; or, when it monitors that the apparent ohmic resistance Ra increases, control the power supply circuit to increase the DC supply voltage.

[0073] As Figure 10 shown, when the apparent ohmic resistance Ra is 0.5 ohm, and the frequency and duty cycle of the switching signal supplied to the transistor switch Q1 are 6.676 MHZ and 53%, the power supply voltage is 3.3 V, the power supply current is approximately 4.2 A, and at this time the power supply power is 3.3 V * 4.2 A = 13.9 W.

[0074] As Figure 11 shown, if the apparent ohmic resistance Ra, the frequency and duty cycle of the switching signal supplied to the transistor switch Q1, are still consistent with Figure 10 Adjust the power supply voltage to 2.5 V, the power supply current is approximately 3.3 A, and at this time the power supply power is 2.5 V * 3.3 A = 8.25 W. That is, by reducing the power supply voltage, the heating power is reduced to maintain a smaller power heating, reduce the heat generation of the transistor switch Q1, and thus further improve the efficiency of the whole machine.

[0075] In an example, the controller is further configured to adjust the frequency and duty cycle of the switching signal supplied to the transistor switch Q1 if the apparent ohmic resistance Ra reaches a preset resistance threshold. That is, it is determined whether the apparent ohmic resistance Ra decreases or increases to the first preset resistance threshold, and the frequency and duty cycle of the switching signal supplied to the transistor switch Q1 are adjusted according to the determination result.

[0076] In an example, the controller is further configured to output a switching signal with a first frequency or / and a first duty cycle during a first time period within a heating cycle to keep the apparent ohmic resistance Ra near a second preset resistance threshold; and output a switching signal with a second frequency or / and a second duty cycle during a second time period within a heating cycle to keep the apparent ohmic resistance Ra near a third preset resistance threshold. Wherein, the second preset resistance threshold may be greater than or less than the third preset resistance threshold.

[0077] Figure 12 is a schematic diagram of the curve of the temperature and time of the sensor provided by the embodiment of the present application. As Figure 12 shown, the puffing period of the aerosol generating device includes three time periods, namely the time period t0 - t1, the time period t1 - t2, and the time period t2 - t3.

[0078] During the time period t0 to t1, the temperature of the sensor rapidly rises from the initial temperature T0 to the target temperature T1, such as 250 °C. Generally, the target temperature T1 is the maximum temperature during a puff of the electronic atomization device 100, and the duration of the time period t0 to t1 is within 1 s, such as 0.2 s, 0.4 s, 0.6 s, 0.8 s, etc., so as to quickly respond to the user's puff. In this stage, the sensor needs to be able to quickly heat up to the desired temperature so as to heat the liquid matrix to generate aerosol as quickly as possible.

[0079] During the time period t1 to t2, the temperature of the sensor 11 drops from the temperature T1 to the temperature T2, and the temperature of the sensor 11 is maintained at T2.

[0080] During the time period t2 to t3, the temperature of the sensor 11 drops from the temperature T2 to the temperature T3, and the temperature of the sensor 11 is maintained at T3.

[0081] In actual work, data such as the preset resistance thresholds corresponding to the three time periods, the frequency and duty cycle of the switching signal of the transistor switch Q1, etc. can be stored in the controller, so that the aerosol generating device operates according to the predetermined desired temperature curve. For example:

[0082] When starting heating, the DC supply voltage provided by the control power circuit is the first DC supply voltage, the frequency of the switching signal supplied to the transistor switch Q1 is the first frequency, and the duty cycle of the switching signal supplied to the transistor switch Q1 is the first duty cycle, so that the temperature of the sensor rapidly rises from the initial temperature T0 to the target temperature T1.

[0083] Monitor the change of the apparent ohmic resistance Ra. When the apparent ohmic resistance Ra reaches the preset resistance threshold corresponding to the target temperature T1, the DC supply voltage provided by the control power circuit is the second DC supply voltage less than the first DC supply voltage, that is, reduce the heating power, the frequency of the switching signal supplied to the transistor switch Q1 is the second frequency, and the duty cycle of the switching signal supplied to the transistor switch Q1 is the second duty cycle, so that the temperature of the sensor 11 drops from the temperature T1 to the temperature T2, and the temperature of the sensor 11 is maintained at T2.

[0084] During the time period t2 to t3, the DC supply voltage provided by the control power circuit is the third DC supply voltage less than the second DC supply voltage, that is, further reduce the heating power, the frequency of the switching signal supplied to the transistor switch Q1 is the third frequency, and the duty cycle of the switching signal supplied to the transistor switch Q1 is the third duty cycle, so that the temperature of the sensor 11 drops from the temperature T2 to the temperature T3, and the temperature of the sensor 11 is maintained at T3.

[0085] Figure 13It is a schematic flowchart of a control method for an aerosol generating device provided by an embodiment of the present application. The control method includes the steps:

[0086] S11. Determine the apparent ohmic resistance based on the DC supply voltage and the DC current output by the power supply circuit to the DC / AC inverter during operation;

[0087] S12. Monitor the change of the apparent ohmic resistance, and when the apparent ohmic resistance changes, adjust the frequency and duty cycle of the switching signal supplied to the transistor switch.

[0088] In an example, when it is monitored that the apparent ohmic resistance decreases, reduce the frequency of the switching signal of the transistor switch and increase the duty cycle of the switching signal of the transistor switch; or when it is monitored that the apparent ohmic resistance increases, increase the frequency of the switching signal of the transistor switch and decrease the duty cycle of the switching signal of the transistor switch.

[0089] In an example, when the apparent ohmic resistance changes, control the power supply circuit to adjust the DC supply voltage.

[0090] In an example, when it is monitored that the apparent ohmic resistance decreases, control the power supply circuit to reduce the DC supply voltage; or when it is monitored that the apparent ohmic resistance increases, control the power supply circuit to increase the DC supply voltage.

[0091] In an example, determine the temperature of the sensor according to the apparent ohmic resistance.

[0092] In an example, determine whether the apparent ohmic resistance decreases or increases to a first preset resistance threshold, and adjust the frequency and duty cycle of the switching signal supplied to the transistor switch according to the judgment result.

[0093] In an example, output a switching signal with a first frequency or / and a first duty cycle during a first time period within a heating cycle to keep the apparent ohmic resistance near a second preset resistance threshold; and output a switching signal with a second frequency or / and a second duty cycle during a second time period within a heating cycle to keep the apparent ohmic resistance near a third preset resistance threshold.

[0094] It should be noted that the description and drawings of the present application provide preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments do not serve as additional limitations to the content of the present application. The purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive. Moreover, the above technical features continue to be combined with each other to form various embodiments not listed above, which are all regarded as within the scope described in the description of the present application. Further, for those of ordinary skill in the art, improvements or modifications can be made based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims of the present application.

Claims

1. An aerosol generating device, characterized in that, Comprising: A power supply circuit for providing a DC supply voltage; A DC / AC inverter connected to the power supply circuit; The DC / AC inverter includes a class E power amplifier, and the class E power amplifier includes a transistor switch and an LC load network composed of a capacitor and an inductor; wherein, the inductor is inductively coupled to a susceptor to heat an aerosol-forming substrate to generate an aerosol; A controller configured to determine an apparent ohmic resistance based on the DC supply voltage and the DC current output from the power supply circuit to the DC / AC inverter during operation; the controller is further configured to monitor a change in the apparent ohmic resistance, and when the apparent ohmic resistance changes, adjust the frequency and duty cycle of the switching signal supplied to the transistor switch.

2. The aerosol generating device according to claim 1, wherein The controller is configured to decrease the frequency of the switching signal of the transistor switch and increase the duty cycle of the switching signal of the transistor switch when it monitors a decrease in the apparent ohmic resistance; or, increase the frequency of the switching signal of the transistor switch and decrease the duty cycle of the switching signal of the transistor switch when it monitors an increase in the apparent ohmic resistance.

3. The aerosol generating device according to claim 1, characterized in that, The power supply circuit is configured to be able to provide a variable DC supply voltage, and the controller is further configured to control the power supply circuit to adjust the DC supply voltage when the apparent ohmic resistance changes.

4. The aerosol generating device according to claim 3, characterized in that, The controller is configured to control the power supply circuit to decrease the DC supply voltage when it monitors a decrease in the apparent ohmic resistance; or, control the power supply circuit to increase the DC supply voltage when it monitors an increase in the apparent ohmic resistance.

5. The aerosol generating device according to claim 3, wherein, The power supply circuit includes a DC-DC conversion circuit and a regulation circuit; The DC-DC conversion circuit includes an input terminal electrically connected to a battery cell, an output terminal for outputting a DC supply voltage, and a feedback terminal; The regulation circuit is configured to receive the control of the controller, so as to generate a regulation signal at the feedback terminal of the DC-DC conversion circuit, such that the DC-DC conversion circuit responds to the regulation signal and converts the battery cell voltage into a corresponding DC supply voltage.

6. The aerosol generating device according to claim 3, wherein, It further includes a voltage detection circuit for detecting the DC supply voltage provided by the power supply circuit.

7. The aerosol generating device according to claim 1, characterized in that, It further includes a current detection circuit for detecting the DC current drawn from the power supply circuit.

8. The aerosol generating device according to claim 1, characterized in that, The controller is further configured to determine the temperature of the susceptor based on the apparent ohmic resistance.

9. The aerosol generating device according to claim 1, wherein, The controller is further configured to judge whether the apparent ohmic resistance decreases or increases to a first preset resistance threshold, and adjust the frequency and duty cycle of the switching signal supplied to the transistor switch according to the judgment result.

10. The aerosol generating device according to claim 1, wherein, The controller is further configured to output a switching signal having a first frequency or / and a first duty cycle during a first time period within a heating cycle, so as to keep the apparent ohmic resistance near a second preset resistance threshold; And output a switching signal having a second frequency or / and a second duty cycle during a second time period within a heating cycle, so as to keep the apparent ohmic resistance near a third preset resistance threshold.

11. A control method for an aerosol generating device, characterized in that, The aerosol generating device includes: A power supply circuit for providing a DC supply voltage; A DC / AC inverter, connected to the power supply circuit; the DC / AC inverter includes a class E power amplifier, and the class E power amplifier includes a transistor switch and an LC load network composed of a capacitor and an inductor; wherein, the inductor is inductively coupled to a receptor to heat an aerosol-forming substrate to generate an aerosol; The method includes: Determining an apparent ohmic resistance based on the DC supply voltage and the DC current output from the power supply circuit to the DC / AC inverter during operation; Monitoring a change in the apparent ohmic resistance, and when the apparent ohmic resistance changes, adjusting the frequency and duty cycle of a switching signal supplied to the transistor switch.

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