CROSS-REFERENCE TO RELATED APPLICATIONS
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This application claims priority to
Chinese Patent Application No. 202310605151.9, filed with the China National Intellectual Property Administration on May 25, 2023 and entitled "ELECTRONIC ATOMIZATION DEVICE AND CONTROL METHOD", which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
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Embodiments of this application relate to the field of electronic atomization technologies, and in particular, to an electronic atomization device and a control method.
BACKGROUND
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During use of tobacco products (for example, cigarettes and cigars), tobaccos are burnt to generate tobacco vapor. Attempts are made to replace these tobacco-burning products by manufacturing products that release compounds without burning tobacco.
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An example of such products is a heating device, which releases compounds by heating rather than burning materials. For example, the materials may be tobacco or other non-tobacco products, where the non-tobacco products may or may not include nicotine. In another example, aerosol providing products exist, for example, the so-called electronic atomization devices. The devices usually include liquid. The liquid is heated to be atomized, so as to generate an inhalable aerosol. In a conventional electronic atomization device, an inhalation action of a user is sensed through an airflow sensor. When the airflow sensor senses the inhalation of the user, an induction coil is controlled to generate a changing magnetic field, to induce a susceptor to generate heat, thereby heating the liquid to generate an aerosol. In an existing electronic atomization device, generation of a changing magnetic field by an induction coil is performed in response to a trigger signal of an airflow sensor. However, when the electronic atomization device further uses a symmetric inductor-capacitor (LC) oscillation circuit with a fixed resonance frequency to invert the induction coil to generate the changing magnetic field, a temperature of the susceptor presents a continuously rising form shown in FIG. 1 within an inhalation duration because the resonance frequency of the LC oscillation circuit and 50% of a duty cycle of a pulse width modulation (PWM) control signal are set to be constant and non-adjustable, which easily generates overheat or affects taste.
SUMMARY
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An embodiment of this application provides an electronic atomization device, including:
- a susceptor, configured to heat an aerosol generating substrate to generate an aerosol;
- an inductor-capacitor (LC) oscillator, including an induction coil and a capacitor, where the LC oscillator is configured to guide a changing current to flow through the induction coil, and then drive the induction coil to provide energy to the susceptor, so that the susceptor heats the aerosol generating substrate; and
- a controller, configured to drive the LC oscillator through an intermittent pulse width modulation (PWM) signal to form a current flowing through the induction coil, and control a pulse density of the PWM signal within a predetermined time, so that a value of the energy provided to the susceptor is maintained at a preset energy value within the predetermined time.
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The foregoing "pulse density" is an electrical term, which refers to a pulse count of a signal per unit time, or a ratio of a pulse count of a signal to a time.
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In some embodiments, the foregoing predetermined time may be a program execution period set by a microcontroller unit (MCU) controller, for example, 300 ms, 500 ms, or 1s. Alternatively, the foregoing predetermined time may be a time of an entire heating process, for example, 3s/4s.
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In some embodiments, the electronic atomization device further includes:
- an airflow sensor, configured to sense an inhalation action of a user, where
- the controller is configured to drive, within a duration of the inhalation action of the user, the LC oscillator through the PWM signal to form a current flowing through the induction coil.
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In some embodiments, the LC oscillator has a resonance frequency; and a frequency of the PWM signal is the same as the resonance frequency of the LC oscillator. Alternatively, the frequency of the PWM signal is unchanged within the duration of the inhalation action of the user.
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The frequency of the foregoing PWM signal is an electrical term, which refers to a derivative of a period of the PWM pulse signal.
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In some embodiments, alternatively, a duty cycle of the PWM signal is unchanged within the duration of the inhalation action of the user. Specifically, the duty cycle of the PWM signal is fixed at 50%.
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In some embodiments, within a duration of a single inhalation action of the user, the predetermined time includes at least a first predetermined time and a second predetermined time that advance in sequence; and a pulse density of the PWM signal within the second predetermined time is less than a pulse density of the PWM signal within the first predetermined time. Alternatively, the duration of the single inhalation action of the user is divided to include a plurality of the predetermined times. Moreover, the pulse density of the PWM signal within the predetermined time decreases as advance of the duration of the single inhalation action of the user.
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In some embodiments, the electronic atomization device further includes:
- a voltage regulator, configured to generate a constant voltage, where
- the controller is configured to control, through the PWM signal, the constant voltage to be provided to the LC oscillator, and then drive the LC oscillator to form the current flowing through the induction coil.
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In some embodiments, the controller is configured to calculate, based on a duration for which the constant voltage is provided to the LC oscillator, the value of the energy provided to the susceptor.
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In some embodiments, the electronic atomization device further includes:
- a battery core, configured to supply power; and
- a first switch transistor and a second switch transistor, where
- the capacitor includes a first capacitor and a second capacitor;
- a first end of the first capacitor is connected to a positive electrode of the battery core, and a second end of the first capacitor is connected to a first end of the second capacitor; a second end of the second capacitor is connected to a negative electrode of the battery core; a first end of the induction coil is connected to the second end of the first capacitor, and a second end of the induction coil is connected to the positive electrode of the battery core through the first switch transistor and is connected to the negative electrode of the battery core through the second switch transistor; and
- the controller is configured to control the first switch transistor through a first PWM signal, and control the second switch transistor through a second PWM signal to be alternately turned on or off, so that the LC oscillator guides the changing current to flow through the induction coil.
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Another embodiment of this application further provides an electronic atomization device, including:
- a susceptor, configured to heat a liquid aerosol generating substrate to generate an aerosol;
- an LC oscillator, including an induction coil and a capacitor, where the LC oscillator is configured to guide a changing current to flow through the induction coil, and then drive the induction coil to induce the susceptor to heat the liquid aerosol generating substrate;
- an airflow sensor, configured to sense an inhalation action of a user, where
- a controller, configured to drive, within a duration of an inhalation action of a user, the LC oscillator through an intermittent PWM signal to form a current flowing through the induction coil, and control a pulse density of the PWM signal, so that a heating temperature of the susceptor is substantially constant.
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Another embodiment of this application further provides a control method for an electronic atomization device, where the electronic atomization device includes:
- a susceptor, configured to heat an aerosol generating substrate to generate an aerosol;
- an LC oscillator, including an induction coil and a capacitor, where the LC oscillator is configured to guide a changing current to flow through the induction coil, and then drive the induction coil to provide energy to the susceptor, so that the susceptor heats the aerosol generating substrate; and
- the method includes:
driving the LC oscillator through an intermittent PWM signal to form a current flowing through the induction coil, and controlling a pulse density of the PWM signal within a predetermined time, so that a value of the energy provided to the susceptor is maintained at a preset energy value within the predetermined time.
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Through the foregoing electronic atomization device, the pulse density of the PWM signal is controlled within an inhalation duration of a user, so that the value of the energy provided to the susceptor is maintained at the preset energy value, and generation or inhalation taste of the aerosol within the inhalation duration is maintained stable.
BRIEF DESCRIPTION OF THE DRAWINGS
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One or more embodiments are illustratively described with reference to the figures in the corresponding accompanying drawings, and these illustrative descriptions are not to limit the embodiments. Elements having same reference numerals in the accompanying drawings are denoted as similar elements, and the figures in the accompanying drawings are not drawn to scale, unless particularly stated otherwise.
- FIG. 1 is a curve of a temperature change of an existing susceptor when a magnetic field is generated in response to trigger of an airflow sensor to induce the susceptor to heat.
- FIG. 2 is a schematic diagram of an electronic atomization device according to an embodiment.
- FIG. 3 is a schematic structural diagram of an embodiment of a circuit in FIG. 2.
- FIG. 4 is a schematic diagram of basic components of an embodiment of a circuit in FIG. 3.
- FIG. 5 is a schematic diagram of a pulse width modulation (PWM) control signal sent by a microcontroller unit (MCU) controller according to an embodiment.
- FIG. 6 is a curve of a temperature change of a susceptor according to an embodiment.
- FIG. 7 is a schematic diagram of basic components of a circuit in another embodiment.
DETAILED DESCRIPTION
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For ease of understanding of this application, this application is described below in more detail with reference to accompanying drawings and specific implementations.
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An embodiment of this application provides an electronic atomization device, which is configured to atomize an aerosol-forming substrate to generate an aerosol. In some embodiments, the electronic atomization device may include two or more parts that are separated from each other or replaced with each other. When the two or more parts are combined, a complete combined use state of the electronic atomization device is formed, and then an aerosol can be generated in response to an operation of a user.
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In some embodiments, the electronic atomization device can generate the aerosol by heating a liquid aerosol-forming substrate. In some embodiments, the liquid aerosol-forming substrate includes at least one of propylene glycol, glycerol, and the like.
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Alternatively, in some other embodiments, the electronic atomization device can volatize or release at least one component of the solid aerosol-forming substrate to form an aerosol for inhalation by heating the solid aerosol-forming substrate. In some embodiments, the solid aerosol-forming substrate is preferably made of a solid substrate, which may include one or more of powders, particles, fragment strips, stripes, or flakes of one or more of vanilla leaves, dried flowers, herbaceous crops with volatile fragrance, tobacco leaves, homogeneous tobacco, and expanded tobacco. Alternatively, the solid substrate may include additional tobacco or non-tobacco volatile aroma compounds to be released when the substrate is heated.
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FIG. 2 is a schematic diagram of an electronic atomization device according to an embodiment. In this embodiment, the electronic atomization device includes an atomizer 100 configured to atomize a liquid aerosol-forming substrate to generate an aerosol and a power supply mechanism 200 configured to supply power to the atomizer.
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Further, as shown in FIG. 2, the power supply mechanism 200 includes:
a proximal end 2110 and a distal end 2120 facing away from each other along a longitudinal direction. During use, the proximal end 2110 is an end configured to receive the atomizer 100.
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As shown in FIG. 2, the power supply mechanism 200 further includes:
a receiving cavity 270, arranged adjacent to the proximal end 2110 and arranged to extend along the longitudinal direction of the power supply mechanism 200, where the receiving cavity 270 has an opening facing toward or located at the proximal end 2110 along the longitudinal direction; and during use, the atomizer 100 can be received in the receiving cavity 270 or removed from the receiving cavity 270 through the opening.
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As shown in FIG. 2, the power supply mechanism 200 further includes:
- a chargeable battery core 210, configured to output electric power, where the battery core 210 is arranged close to the distal end 2120; and
- a charging interface 240, configured to charge the chargeable battery core 210, where the charging interface 240 is arranged between the battery core 210 and the distal end 2120.
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In an embodiment, a direct current supply voltage provided by the battery core 210 ranges from about 2.5V to about 9.0V, and an amperage of the direct current the battery core 210 can provide ranges from about 2.5A to about 20A. In a specific embodiment, the direct current supply voltage provided by the battery core 210 ranges from 3.2V to 4.2V.
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As shown in FIG. 2, the power supply mechanism 200 further includes:
a circuit 220 integrated or arranged on a circuit board, for example, a printed circuit board (PCB) board, which is configured to control operation of the power supply mechanism 200. Particularly, the circuit 220 is configured to control electric power outputted by the battery core 210. In addition, in FIG. 2, the circuit 220 is located between the battery core 210 and the receiving cavity 270.
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As shown in FIG. 2, the power supply mechanism 200 further includes:
an airflow sensor 250, for example, a microphone/micro-electro-mechanical system (MEMS) sensor and the like, which is configured to sense an inhalation airflow flowing through the atomizer 100 when a user inhales on the atomizer 100. The circuit 220 is configured to control the battery core 210 to output electric power based on a sensing result of the airflow sensor 250. In the embodiment shown in FIG. 2, the airflow sensor 250 is arranged between the battery core 210 and the receiving cavity 270. In addition, in some other variant embodiments, the airflow sensor 250 may alternatively be assembled, fastened, or coupled to a circuit board on which the circuit 220 is arranged. Alternatively, in some other variant embodiments, the airflow sensor 250 is supported and fixed in the power supply mechanism 200 through an independent support element such as a plastic support.
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In some embodiments, the power supply mechanism 200 is configured to induce the atomizer 100 to heat the liquid aerosol-forming substrate by generating a changing magnetic field that passes through the receiving cavity 270. Specifically, an induction heating element may be arranged in the atomizer 100. When the atomizer 100 is received in the receiving cavity 270, the atomizer can be penetrated by a changing magnetic field to generate heat, so as to heat the liquid aerosol-forming substrate to generate an aerosol.
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As shown in FIG. 2, the power supply mechanism 200 further includes:
- an induction coil 260, arranged around the receiving cavity 270; and
- a circuit 220, driven based on a predetermined frequency to form an alternating current flowing through the induction coil 260, so that the induction coil 260 generates a changing magnetic field that can penetrate the receiving cavity 270. In some embodiments, a frequency of the alternating current supplied by the circuit 220 to the induction coil 260 ranges from 80 KHz to 2000 KHz. More specifically, the frequency may be in a range of approximately 600 KHz to 1500 KHz.
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In addition, in some embodiments, the induction coil 260 is wrapped by a wire material with a low electrical resistance, for example, a copper wire, a silver wire, or the like. Moreover, in some other variant embodiments, the induction coil 260 is wrapped by a Litz wire. A Litz wire having a plurality of strands or bundles of wires are more favorable for carrying an alternating current.
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FIG. 2 is a schematic diagram of an atomizer 100 according to an embodiment. In this embodiment, the atomizer 100 includes:
- a main housing 10; and
- a separation wall 11, extending inside the main housing 10 along a longitudinal direction of the atomizer 100, where the separation wall 11 and the main housing 10 are integrally molded, for example, molded by a material such as a polymer or a ceramic, and the separation wall 11 extends to or ends at an air outlet 111. Moreover, a liquid storage cavity 12 is defined between the separation wall 11 and the main housing 10, and is configured to store a liquid aerosol-forming substrate. In addition, the separation wall 11 surrounds and defines an aerosol output channel located in the main housing 10, so as to output an aerosol to the air outlet 111 during inhalation.
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The atomizer 100 further includes:
an atomization assembly configured to atomize a liquid aerosol-forming substrate to generate the aerosol. In FIG. 2, the atomization assembly includes a liquid guide element 20 configured to absorb and store the liquid aerosol-forming substrate and a susceptor 30 coupled to the liquid guide element 20 and configured to heat the liquid aerosol-forming substrate to generate the aerosol.
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In an embodiment shown in FIG. 2, the liquid guide element 20 is configured to be located inside the separation wall 11. Moreover, the liquid guide element 20 is constructed as a hollow cylinder extending along the longitudinal direction. In some embodiments, the liquid guide element 20 is made of a capillary material or a porous material, for example, a sponge, a cotton fiber, or a porous body such as a porous ceramic body. An outer side surface of the liquid guide element 20 is configured as a liquid absorbing surface, and is configured to absorb the liquid aerosol-forming substrate from the liquid storage cavity 12. In some specific embodiments, the separation wall 11 is provided with several through holes, and the outer side surface of the liquid guide element 20 absorbs the liquid aerosol-forming substrate in the liquid storage cavity 12 through the through holes. An inner side surface of the liquid guide element 20 is configured as an atomization surface. The susceptor 30 is coupled to the inner side surface of the liquid guide element 20. At least part of the liquid aerosol-forming substrate in the liquid guide element 20 is heated to generate the aerosol.
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In some other embodiments, the liquid guide element 20 may further be constructed in various regular or irregular shapes, and partially in fluid communication with the liquid storage cavity 12 to receive the liquid aerosol-forming substrate. Alternatively, in another variant implementation, the liquid guide element 20 may have more regular or irregular shapes, such as a polygonal block shape, a channel shape having a groove on a surface, or an arch shape having a hollow channel inside.
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Alternatively, in some other variant implementations, the susceptor 30 may be coupled to the liquid guide element 20 through printing, deposition, sintering, physical assembly, or the like. In some other variant implementations, the liquid guide element 20 may have a flat surface or a curved surface for supporting the susceptor 30, and the susceptor 30 is formed on the flat surface or the curved surface of the liquid guide element 20 of the porous body through mounting, printing, deposition, and the like.
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In the embodiment shown in FIG. 2, the susceptor 30 is an induction heating element that can be penetrated by the changing magnetic field to generate heat. The susceptor 30 is made of a metal or an alloy with sensitivity. For example, the susceptor 30 may be made of stainless steel of grade 430 (SS430), or may be made of stainless steel of grade 420 (SS420) and an alloy material (such as permalloy) containing iron and nickel. In addition, in some specific embodiments, the susceptor 30 has a length in a range of 2 mm to 10 mm; and the susceptor 30 has an inner diameter in a range of 1.5 mm to 8 mm; and a wall thickness of the susceptor 30 ranges from 0.05 mm to 0.2 mm. For example, in some specific embodiments, the susceptor 30 has a length in a range of 4 mm to 8 mm. As shown in FIG. 2, the susceptor 30 is of a tubular shape closed in a circumferential direction. Moreover, the susceptor 30 is a network structure. The susceptor 30 has several eyelets arranged in an array, which are configured to release the aerosol.
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Alternatively, in some other variant embodiments, the susceptor 30 may be constructed in a shape of a solenoid, or in more cylindrical shapes.
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In the embodiment shown in FIG. 2, an extension length of the induction coil 260 ranges from 6 mm to 15 mm. Moreover, the induction coil 260 has approximately 6 to 12 turns. A length of the susceptor 30 is less than a length of the induction coil 260. Therefore, when the atomizer 100 is received in the receiving cavity 270, the susceptor 30 is substantially completely located in the induction coil 260.
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FIG. 3 is a schematic structural diagram of a circuit 220 according to an embodiment. In this embodiment, the circuit 220 includes:
- a microcontroller unit (MCU) controller 221;
- an inductor-capacitor (LC) oscillator 222, including an induction coil 260 and a capacitor, where in some embodiments, the LC oscillator 222 may be an asymmetric LC oscillator 222 including a capacitor and an induction coil 260 and having only one oscillation bridge arm; or in some other embodiments, the LC oscillator 222 is a symmetric LC oscillator 222 including two symmetric oscillation bridge arms formed by two capacitors and an induction coil 260; and
- a half-bridge 224 (a basic term in the electrical field), including two switch transistors, located between the battery core 210 and the LC oscillator 222.
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During use, when the airflow sensor 250 senses an inhalation of the user, the MCU controller 221 controls turn-on/turn-off of the switch transistors in the half-bridge 224 based on the sensing of the airflow sensor 250, so that the LC oscillator 222 oscillates and generates an alternating current that flows through the induction coil 260, thereby generating a magnetic field to induce the susceptor 30 to heat.
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FIG. 4 is a schematic diagram of basic components of a specific embodiment of a circuit 220 in FIG. 3. As shown in FIG. 4, the circuit 220 includes:
- a symmetric LC oscillator 222, including an induction coil 260, a capacitor C1, and a capacitor C2, where the capacitor C1 and the capacitor C2 respectively form symmetric bridge arms with the induction coil 260; and
- a half-bridge 224, including a switch transistor Q1 and a switch transistor Q2, where in this embodiment, a connection manner between the half-bridge 224 and the symmetric LC oscillator 222 is specifically as follows.
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A first end of the capacitor C1 is connected to a positive electrode of the battery core 210, and a second end thereof is connected to a first end of the capacitor C2; a second end of the capacitor C2 is connected to a negative electrode of the battery core 210; a first end of the induction coil 260 is connected to a second end of the capacitor C1, and a second end thereof is connected to the positive electrode of the battery core 210 through the switch transistor Q1 and is connected to the negative electrode of the battery core 210 through the switch transistor Q2.
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The switch transistor Q1 is controlled to turn on or off through a first pulse width modulation (PWM) control signal sent by the MCU controller 221. The switch transistor Q2 is controlled to turn on or off through a second PWM control signal sent by the MCU controller 221.
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In some embodiments, for such an electronic atomization device that needs to respond to an inhalation action of the user most rapidly to generate the aerosol, a frequency of a PWM control signal generally adapts to a natural resonance frequency of the symmetric LC oscillator 222, so that the LC oscillator 222 substantially oscillates based on maximum resonance efficiency, to generate the aerosol most rapidly. Therefore, in this embodiment, for such a symmetric LC oscillator 222, a frequency of the PWM control signal sent by the MCU controller 221 is constant, to prevent that the LC oscillator 222 fails to resonate and cannot provide the aerosol when a frequency at which the PWM control signal is used is inconsistent with a natural resonance frequency of the LC oscillator 222.
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In some embodiments, in inversion control of the half-bridge, the switch transistor Q1 and the switch transistor Q2 are alternately turned on or off. In this case, the first PWM control signal sent by the MCU controller 221 to the switch transistor Q1 and the second PWM control signal sent by the MCU controller to the switch transistor Q2 generally have complementary duty cycles. Further, for such a symmetric LC oscillator 222, an oscillation process (usually including a positive process and a negative process) needs to be symmetrically performed in an oscillation control process. Therefore, duty cycles of the PWM control signal sent by the MCU controller 221 to the switch transistor Q1 and the PWM control signal sent by the MCU controller to the switch transistor Q2 are both fixed at 50%, and are substantially constant.
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For example, FIG. 5 is a schematic diagram of a first PWM control signal that controls a switch transistor Q1 to be turned on or off and a second PWM control signal that controls a switch transistor Q2 to be turned on or off sent by an MCU controller 221 according to an embodiment.
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As shown in FIG. 5, the first PWM control signal and the second PWM control signal are both square waves of pulses. A high/low level in the first PWM control signal is opposite to a high/low level in the second PWM control signal. In addition, the first PWM control signal and the second PWM control signal are simultaneous. Moreover, the first PWM control signal and the second PWM control signal have a same duty cycle, which is 50%. In addition, the first PWM control signal and the second PWM control signal have a same period, which is T1. Moreover, the first PWM control signal and the second PWM control signal also have a same frequency.
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In some embodiments, when the airflow sensor 250 senses an inhalation action of the user and triggers the action, the MCU controller 221 is configured to control to send the first PWM control signal and the second PWM control signal based on a trigger signal of the airflow sensor 250.
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In the embodiment of FIG. 5, the MCU controller 221 is configured to control, in a pulse density modulation (PDM) modulation manner, a pulse density (a ratio of a pulse count to a time, which is a ratio of a pulse count to an inhalation duration t100 in this embodiment) of the first PWM control signal and the second PWM control signal within the inhalation duration t100 of the user sensed by the airflow sensor 250. Moreover, the pulse density of the first PWM control signal and the pulse density of the second PWM control signal are modulated by the MCU controller 221 in the PDM modulation manner based on a preset energy value required to be provided to the susceptor 30.
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For example, in some specific embodiments, the preset energy value set in the MCU controller 221 and provided to the susceptor 30 is 35 J/3s. In other words, when the inhalation duration t100 of the user is usually 3s, energy that needs to be provided to the susceptor 30 is 35J, to output a control signal.
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Alternatively, in some other descriptions, the MCU controller 221 is configured to modulate, based on the preset energy value provided to the susceptor 30 per unit time, the pulse density of the PWM control signal. The energy provided to the susceptor 30 in the unit time is 35 1/3s=11.66667 J/s.
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In this embodiment, when the duty cycle and the frequency of the PWM control signal both need to be kept unchanged, the pulse density modulation of the first PWM control signal and the second PWM control signal is performed based on the preset energy value provided to the susceptor 30, so that substantially uniform energy is provided to the susceptor 30 within the inhalation duration t100. When the substantially uniform energy is provided to the susceptor 30, a temperature curve of the susceptor 30 on which an eddy effect generates heat is shown in a form shown in FIG. 6. In FIG. 6, due to temperature sensitivity of an eddy heating, after the temperature of the susceptor 30 instantaneously rises from a room temperature to a temperature T0, the temperature of the sensor is substantially kept constant around the temperature T0, to generate the aerosol. Therefore, generation efficiency of the aerosol is substantially uniform at a substantially constant temperature within a single inhalation duration or a single heating period, so as to have a better taste compared with the existing gradually increasing temperature in FIG. 1.
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In the specific embodiment shown in FIG. 5, the MCU controller 221 modulates an interval between the PWM control signals in the PDM modulation manner, so as to change the pulse density of the PWM control signals. For example, specifically, interval time periods between adjacent PWM control signals are modulated through the PDM, such as an interval time period t11 and an interval time period t21 shown in FIG. 5, so as to change the pulse density of the PWM control signals.
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In some embodiments, the pulse density of the PWM control signal is substantially constant in a plurality of predetermined times (for example, 1s) within the inhalation duration t100 (for example, 3s) sensed by the airflow sensor 250.
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Alternatively, in some other variant embodiments, in the plurality of predetermined times (for example, 1s) of the single inhalation duration t100 (for example, 3s) sensed by the airflow sensor 250, the pulse density of the PWM control signal in the plurality of predetermined times (for example, 1s) is gradually reduced. An objective of this setting is that, at the beginning of the single inhalation, for example, the 1s, relatively much energy may be needed because the susceptor 30 rises from a normal temperature (or referred to as a cold state) to the temperature T0, and relatively little energy is needed subsequently at the 2s or the 3s because the susceptor 30 has an equivalent temperature (or referred to as a hot state) to instantly maintain a corresponding temperature. Therefore, the pulse density of the PWM control signal in the 2s or the 3s is less than the pulse density in the 1s as a duration of the inhalation is advanced, so that the susceptor 30 presenting a temperature curve in FIG. 6 is advantageous.
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As shown in FIG. 4, the circuit 220 further includes:
a voltage regulator 223, for example, a common boost chip or buck voltage regulator chip, where the voltage regulator 223 is connected between the positive electrode of the battery core 210 and the half-bridge 224, to provide a constant driving voltage to the LC oscillator 222. During use, as the battery core 210 continuously discharges, an output voltage of the positive electrode of the battery core 210 gradually decreases. For example, when the battery core is fully charged, the output voltage of the positive electrode of the battery core 210 is 4.2V, and when the battery core is at a low charge, the output voltage is 3.2V at a minimum. A constant driving voltage, for example, 4.0V, 4.5V, or 6.0V, may be outputted to the LC oscillator 222 through the voltage regulator 223. After a constant output voltage is formed through the voltage regulator 223, the MCU controller 221 is facilitated to calculate and provide balanced energy to the susceptor 30.
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Because a value of the energy that is provided by the induction coil 260 in the LC oscillator 222 to the susceptor 30 through the magnetic field is related to a duration for which the constant voltage is outputted to the LC oscillator 222 through the voltage regulator 223, the value of the energy is substantially in positive correlation. Therefore, in this embodiment, when the voltage regulator 223 outputs a stable driving voltage such as 4.0V, 4.5V, or 6.0V, the MCU controller 221 can calculate a value of the energy provided to the susceptor 30 through only a sum of a turn-on time of the switch transistor Q1 and a turn-on time of the switch transistor Q2 in the half-bridge 224. However, when no stable driving voltage provided by the voltage regulator 223 exists, it is difficult to calculate, based on the positive electrode voltage outputted by the battery core 210 and having relatively large fluctuation, the value of the energy provided to the susceptor 30.
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Specifically, in FIG. 5, the voltage regulator 223 uses a common boost chip, and main electronic devices include:
- a boost inductor L1, configured to provide boost;
- a filter capacitor C3, configured to filter the boosted voltage to output;
- a divider resistor R21 and a resistor R22, connected in series; and
- a switch transistor Q3 and a switch transistor Q4, where the MCU controller 221 monitors the voltage divided by the resistor R22 to determine the boosted voltage value during use, and then keeps the boosted voltage value at a required preset value such as 4.0V, 4.5V, or 6.0V by controlling the switch transistor Q3 and the switch transistor Q4 to be turned on or off.
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Alternatively, FIG. 7 is a schematic diagram of basic components of a circuit 220 according to another embodiment. In the embodiment shown in FIG. 7, the circuit 220 includes:
- an asymmetric LC oscillator 222a, having only one bridge arm formed by a capacitor C2 connected in series with an induction coil 260a;
- a half-bridge 224a, including a switch transistor Q1 and a switch transistor Q2; and
- a voltage regulator 223a, electrically connected between a half-bridge 224a and a positive electrode of a battery core 210.
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The MCU controller 221a is configured to send a first PWM control signal to the switch transistor Q1 to control the switch transistor Q1 to be turned on or off, and send a second PWM control signal to the switch transistor Q2 to control the switch transistor Q2 to be turned on or off.
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In the embodiment of FIG. 7, the MCU controller 221a may send the first PWM control signal and the second PWM control signal with a constant frequency of the natural resonance frequency and a constant duty cycle of 50% in the manner shown in FIG. 5. Moreover, the MCU controller 221a may modulate the pulse density of the first PWM control signal and/or the second PWM control signal within a trigger duration of the airflow sensor 250 based on a preset energy value required to be provided to the susceptor 30.
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In the foregoing embodiment, the circuit 220 drives the oscillation of the LC oscillators 222/222a through the half-bridges 224/224a including the switch transistor Q1 and the switch transistor Q2.
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Alternatively, in some other variant embodiments, the circuit 220 drives the oscillation of the LC oscillators 222/222a through a symmetric full-bridge or an H-bridge. The full-bridge or the H-bridge is a basic term in the electrical field, and a shape thereof resembles a letter H. Therefore, a name "H-bridge" is obtained, and specifically includes four switch transistors that form 4 vertical legs of the letter H, so that a load of the LC oscillator 222a connected in series is a horizontal bar in the H-bridge, thereby forming driving of the full-bridge or the H-bridge. In addition, the oscillation of the LC oscillators 222/222a driven based on the full-bridge or the H-bridge is also symmetric.
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Moreover, in a similar embodiment, the MCU controller 221a may modulate the pulse density of the PWM control signal based on the preset energy value that needs to be provided to the susceptor 30 within the trigger duration of the airflow sensor 250, so as to control the four switch transistors in the full-bridge or the H-bridge to be turned on or off, thereby controlling the oscillation of the LC oscillator 222a.
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It should be noted that, although the specification and the accompanying drawings of this application provide the preferred embodiments of this application, this application is not limited to the embodiments described in this specification. Further, a person of ordinary skill in the art may make improvements or modifications according to the above descriptions, and all of the improvements and modifications shall fall within the protection scope of the appended claims of this application.