Heat-not-burn electric heating atomization gasification device and power converter used in heat-not-burn electric heating atomization gasification device

Abstract

The invention provides a heat-not-burn electric heating atomization gasification device and a power converter used in the heat-not-burn electric heating atomization gasification device. The power converter comprises a microcontroller, a driving circuit, a first buck-boost power switch tube, a second buck-boost power switch tube and a buck-boost inductor. The first terminal of the first buck-boost power switch tube is used for connecting the positive electrode of the lithium battery, and the second terminal is connected to the first terminal of the second buck-boost power switch tube and the first terminal of the buck-boost inductor. And the second terminal of the second buck-boost power switch tube is used for connecting the first terminal of the heating body. And a second terminal of the lifting voltage inductor is grounded. The microcontroller detects the battery voltage of the lithium battery, calculates the duty ratio of the square wave signal based on the battery voltage of the lithium battery and the target output voltage of the power converter, and provides the square wave signal to the driving circuit. The driving circuit generates at least one of a first driving signal and a second driving signal for the first boost-buck power switch tube and the second boost-buck power switch tube based on the square wave signal, so that the first boost-buck power switch tube and the second boost-buck power switch tube are switched on alternately.

Description

Technical Field

[0001] The present invention generally relates to the field of circuits, and more particularly to a heat-not-burn electric heating atomization and vaporization device and a power converter used therein. Background Art

[0002] Generally, a heat-not-burn electric heating atomization and vaporization device includes components such as a battery, a power converter, a heating element, etc. Its core function is to control the temperature of the heating element. Among them, the battery is generally a lithium-ion battery, and the discharge voltage range is between 2.7V and 4.2V; the heating element is generally a metal needle or a metal cup with a resistance characteristic, and the resistance value is between 0.15Ω and 1.2Ω.

[0003] In a heat-not-burn electric heating atomization and vaporization device, the power converter converts the battery voltage into the voltage across the heating element. Under the action of this voltage, a current proportional to the output voltage of the power converter flows through the heating element, and the heat generated by this current realizes the atomization or vaporization of the object to be heated. Among them, the heating temperature of the heating element can be controlled by controlling the output voltage of the power converter. Summary of the Invention

[0004] A power converter used in a heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention includes a microcontroller, a driving circuit, a first buck-boost power switch tube, a second buck-boost power switch tube, and a buck-boost inductor. The first terminal of the first buck-boost power switch tube is used to connect to the positive electrode of the lithium battery, the second terminal is connected to the first terminal of the second buck-boost power switch tube and the first terminal of the buck-boost inductor, the second terminal of the second buck-boost power switch tube is used to connect to the first terminal of the heating element, and the second terminal of the buck-boost inductor is grounded. Wherein: the microcontroller is configured to detect the battery voltage of the lithium battery, calculate the duty cycle of the square wave signal based on the battery voltage of the lithium battery and the target output voltage of the power converter, and provide the square wave signal to the driving circuit; the driving circuit is configured to receive the square wave signal and generate at least one of a first driving signal for the first buck-boost power switch tube and a second driving signal for the second buck-boost power switch tube based on the square wave signal, so that the first buck-boost power switch tube and the second buck-boost power switch tube conduct alternately.

[0005] A heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention includes the above power converter. Brief Description of the Drawings

[0006] The present invention can be better understood from the following description of the specific embodiments of the present invention in conjunction with the drawings, where:

[0007] Figure 1 Shows a schematic circuit diagram of a battery chopper type power converter used in a heat-not-burn electric heating atomization and vaporization device.

[0008] Figure 2 Shows a schematic circuit diagram of a boost chopper type power converter used in a heat-not-burn electric heating atomization and vaporization device.

[0009] Figure 3 Shows a schematic circuit diagram of a full-bridge buck-boost type power converter used in a heat-not-burn electric heating atomization and vaporization device.

[0010] Figure 4 Shows a schematic circuit diagram of a buck-boost type power converter used in a heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention.

[0011] Figure 5 Shows a schematic circuit diagram of an exemplary implementation of a buck-boost type power converter used in a heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention. Detailed implementation manners

[0012] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only provided to better understand the present invention by showing examples of the present invention. The present invention is in no way limited to any specific configuration and algorithm proposed below, but covers any modification, replacement, and improvement of elements, components, and algorithms without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and technologies are not shown in order to avoid unnecessarily obscuring the present invention. Additionally, it should be noted that the term "A is connected to B" used herein may mean "A is directly connected to B" or "A is indirectly connected to B via one or more other elements".

[0013] Currently, the mainstream power converters used in heat-not-burn electric heating atomization and vaporization devices include battery chopper type, boost chopper type, and full-bridge buck-boost type power converters.

[0014] Figure 1 Shows a schematic circuit diagram of a battery chopper type power converter used in a heat-not-burn electric heating atomization and vaporization device. As Figure 1As shown, the battery chopper type power converter 100 includes a chopper switch tube PMOS1, a heating element resistance detection switch tube PMOS2, a heating element resistance detection resistor Rs, and a microcontroller MCU. Among them: when the chopper switch tube PMOS1 is in the off state and the heating element resistance detection switch tube PMOS2 is in the on state, the battery voltage V1 of the lithium battery DC is applied to the series branch composed of the heating element resistance detection resistor Rs and the heating element R. The microcontroller MCU detects the voltage V2 across the series branch composed of the heating element resistance detection resistor Rs and the heating element R through the analog-to-digital conversion module ADC1, and detects the voltage V3 across the heating element R through the analog-to-digital conversion module ADC2. According to Kirchhoff's law, the resistance value of the heating element R is R = Rs × V3 / (V2 - V3). Since the temperature of the heating element R and its resistance value are in one-to-one correspondence, the actual temperature of the heating element R can be obtained by detecting the resistance value of the heating element R. The output voltage of the battery chopper type power converter 100 (i.e., the voltage V3 across the heating element R) can be increased or decreased according to the comparison result between the target temperature and the actual temperature of the heating element R, so as to control the heating element R to reach the target temperature.

[0015] Specifically, in Figure 1 the shown battery chopper type power converter 100, the microcontroller MCU controls the chopper switch tube PMOS1 to switch between the on state and the off state with a fixed period T and a duty cycle D via the general-purpose input / output port GPIO1. Among them, the duty cycle D = (the duration Ton when PMOS1 is in the on state in the fixed period T) / the fixed period T, Ton ≤ T. Under the action of this control method, the voltage V3 across the heating element R = V1 × D, and the current I flowing through the heating element R = V3 / R = V1 × D / R. Under the condition that the battery voltage V1 of the lithium battery DC remains unchanged, the current I flowing through the heating element R is proportional to the duty cycle D. The microcontroller MCU can control the heating element R to reach the target temperature by increasing or decreasing the duty cycle D.

[0016] Figure 1The shown battery chopper type power converter 100 has the following disadvantages: 1) The battery voltage V1 of the lithium battery DC decreases as the power of the lithium battery DC decreases, and there is an uncontrolled range where the voltage V3 across the heating element R cannot make the heating element R reach the target temperature. For example, when the voltage V3 across the heating element R required for the heating element R to reach the target temperature is 3.3V, but the battery voltage V1 of the lithium battery DC is lower than 3.3V (for example, V1 = 3.1V), even if the chopper switch tube PMOS1 switches between the on state and the off state with a duty cycle D = 100% (that is, always in the on state), the voltage V3 across the heating element R can only be V3 = V1×D = 3.1V < 3.3V, which will cause insufficient temperature of the heating element R, insufficient atomization and gasification of the object to be heated, and adverse consequences such as blockage of the evaporation holes. If the uncontrolled range is simply avoided, part of the battery power of the lithium battery DC will be wasted. For example, when the voltage V3 across the heating element R required for the heating element R to reach the target temperature is 3.3V, if the heating element R is controlled not to heat at a voltage lower than this voltage, the power part of the lithium battery DC with a battery voltage V1 lower than 3.3V will be completely wasted. 2) The battery voltage V1 of the lithium battery DC is relatively high when the battery is fully charged, and the instantaneous voltage V3 across the heating element R is relatively high, resulting in a relatively high instantaneous temperature of the heating element R. The excessively high instantaneous temperature will cause the object to be heated to coke and generate harmful substances. For example, when the voltage V3 across the heating element R required for the heating element R to reach the target temperature is 3.3V and the battery voltage V1 of the lithium battery DC = 4.2V, if the resistance R of the heating element R = 1Ω, although the average voltage across the heating element R is 3.3V and the average power is 13.86W under the condition of a duty cycle D = V3 / V1 = 78.57%, during the period when the chopper switch tube PMOS1 is in the on state, the instantaneous power of the heating element R can reach 17.64W, which is much higher than the average power.

[0017] Figure 2 The circuit structure diagram of the boost chopper type power converter used in the non-combustion electric heating atomization and gasification device is shown. As Figure 2 shown, the boost chopper type power converter 200 includes a boost inductor L, boost power switch tubes NMOS1 and NMOS2, a half-bridge drive circuit 1, a capacitor C, a chopper switch tube PMOS1, a heating element resistance detection switch tube PMOS2, a heating element resistance detection resistor Rs, and a microcontroller MCU. Compared with the battery chopper type power converter 100, the boost chopper type power converter 200 adds a boost inductor L, boost power switch tubes NMOS1 and NMOS2, a half-bridge drive circuit 1, and a capacitor C, and these components form a boost circuit, which is controlled by the microcontroller MCU via the general-purpose input / output port GPIO3.

[0018] Specifically, in Figure 2In the boost chopper type power converter 200 shown, the microcontroller MCU outputs a square wave signal with a fixed period T2 and a duty cycle D2 to the half-bridge drive circuit 1 via the general-purpose input / output port GPIO3, where D2 = (the duration Ton2 when NMOS2 is in the on state during the fixed period T2) / T2. The half-bridge drive circuit 1 receives the square wave signal output by the microcontroller MCU via the general-purpose input / output port GPIO3, and converts the square wave signal into drive signals with opposite phases to drive the boost power switch tubes NMOS1 and NMOS2 to conduct alternately, and thereby converts the battery voltage V1 of the lithium battery DC into the voltage V4 = V1 / (1 - D2) across the capacitor C. The microcontroller MCU controls the duty cycle D2 to keep the voltage V4 across the capacitor C unchanged all the time during the process of the battery voltage V1 of the lithium battery DC changing due to the change in the battery charge. The microcontroller MCU controls the chopper switch tube PMOS1 to switch between the on state and the off state with a fixed period T and a duty cycle D via the general-purpose input / output port GPIO1, where the duty cycle D = (the duration Ton when PMOS1 is in the on state during the fixed period T) / the fixed period T, Ton ≤ T. Under the action of this control method, the voltage across the heating element R (i.e., the output voltage of the boost chopper type power converter 200) V3 = V4×D, and the current flowing through the heating element R I = V3 / R = V4×D / R. Since the voltage V4 across the capacitor C is controlled and does not change with the battery voltage V1 of the lithium battery DC, the boost chopper type power converter 200 can overcome the shortcoming 1 of the battery chopper type power converter 100 and effectively avoid the waste of the battery charge of the lithium battery DC. Due to the limitation of the boost circuit, the voltage V4 across the capacitor C is greater than or equal to the battery voltage V1 of the lithium battery DC. Therefore, when the lithium battery DC is fully charged, the boost chopper type power converter 200 cannot overcome the shortcoming 2 of the battery chopper type power converter 100.

[0019] Figure 3 The circuit structure diagram of the full-bridge buck-boost type power converter used in the heat-not-burn electric heating atomization and vaporization device is shown. As Figure 3 shown, the full-bridge buck-boost type power converter 300 includes a boost inductor L, boost power switch tubes NMOS1 and NMOS2, buck power switch tubes NMOS3 and NMOS4, a half-bridge drive circuit 1, a half-bridge drive circuit 2, a capacitor C, a chopper switch tube PMOS1, a heating element resistance detection switch tube PMOS2, a heating element resistance detection resistor Rs, and a microcontroller MCU. Compared with the boost chopper type power converter 200, the full-bridge buck-boost type power converter 300 adds buck power switch tubes NMOS3 and NMOS4 and a half-bridge drive circuit 2, and these components form a buck circuit, which is controlled by the microcontroller MCU via the general-purpose input / output port GPIO4.

[0020] Specifically, in the full-bridge buck-boost power converter 300 shown in Figure 3 , the microcontroller MCU outputs a square wave signal with a fixed period T3 and a duty cycle D3 to the half-bridge drive circuit 2 via the general-purpose input / output port GPIO4, where D3 = (the duration Ton3 when NMOS3 is in the on state during the fixed period T3) / T3. The half-bridge drive circuit 2 receives the square wave signal output by the microcontroller MCU via the general-purpose input / output port GPIO4 and converts the square wave signal into drive signals with opposite phases to drive the buck power switch tubes NMOS3 and NMOS4 to conduct alternately. The microcontroller MCU controls the boost power switch tube NMOS1 to be close to always on and the boost power switch tube NMOS2 to be close to always off via the general-purpose input / output port GPIO3, thereby converting the battery voltage V1 of the lithium battery DC into the voltage V4 across the capacitor C, where V4 ≈ V1×D3. When the lithium battery DC is fully charged and the battery voltage V1 is relatively high, the microcontroller MCU controls the duty cycle D3 via the general-purpose input / output port GPIO4 so that the voltage V4 across the capacitor C is reduced, overcoming the disadvantage 2 of the battery chopper power converter 100 and avoiding the instantaneous temperature of the heating element R being too high due to excessive instantaneous output power. The microcontroller MCU controls the duty cycle D3 to be close to 100% via the general-purpose input / output port GPIO4, and controls the boost process of the boost power switch tubes NMOS1 and NMOS2 via the general-purpose input / output port GPIO3 to be the same as that of the boost chopper power converter 200, so it can also overcome the disadvantage 1 of the battery chopper power converter 100. However, compared with the battery chopper power converter 100 and the boost chopper power converter 200, the system cost of the full-bridge buck-boost power converter 300 increases, and the system efficiency decreases, resulting in energy consumption waste.

[0021] In view of one or more of the above problems, a buck-boost power converter used in a heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention is proposed, which can not only meet the buck-boost function requirements, but also reduce the number of power switch tubes, improve the system efficiency, and reduce the power consumption.

[0022] Figure 4 The circuit structure schematic diagram of the buck-boost power converter used in the heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention is shown. As Figure 4As shown, the buck-boost power converter 400 includes a buck-boost power switch Q1, a buck-boost power switch Q2, a buck-boost inductor L, a drive circuit 402, and a microcontroller MCU, where: the first terminal of the buck-boost power switch Q1 is used to connect to the positive electrode of the lithium battery DC, and the second terminal is connected to the first terminal of the buck-boost power switch Q2 and the first terminal of the buck-boost inductor L. The second terminal of the buck-boost power switch Q2 is used to connect to the first terminal of the heating element R, and the second terminal of the buck-boost inductor L is grounded; the microcontroller MCU is configured to detect the battery voltage V1 of the lithium battery DC, calculate the duty cycle of the square wave signal based on the battery voltage V1 of the lithium battery DC and the target output voltage of the buck-boost power converter 400, and provide the square wave signal to the drive circuit 402; the drive circuit 402 is configured to receive the square wave signal and generate at least one of a drive signal DR1 for the buck-boost power switch Q1 and a drive signal DR2 for the buck-boost power switch Q2 based on the square wave signal, so that the buck-boost power switch Q1 and the buck-boost power switch Q2 conduct alternately.

[0023] As Figure 4 shown, in some embodiments, the buck-boost power converter 400 may further include a capacitor C, where the first terminal of the capacitor C is connected to the second terminal of the buck-boost power switch Q2, and the second terminal is grounded.

[0024] As Figure 4 shown, in some embodiments, the buck-boost power converter 400 may further include a reference voltage source 404, an output voltage detection resistor R1, and an output voltage detection resistor R2, where the first terminal of the output voltage detection resistor R1 is connected to the reference voltage source 404, the second terminal is connected to the first terminal of the output voltage detection resistor R2, and the second terminal of the output voltage detection resistor R2 is connected to the second terminal of the buck-boost power switch Q2. In this case, the microcontroller MCU may further be configured to detect the voltage at the connection point between the output voltage detection resistor R1 and the output voltage detection resistor R2, so as to detect the output voltage of the buck-boost power converter 400.

[0025] As Figure 4 shown, in some embodiments, the buck-boost power converter 400 may further include a heating element resistance detection resistor Rs, where the first terminal of the heating element resistance detection resistor Rs is used to connect to the second terminal of the heating element R, and the second terminal is grounded.

[0026] As Figure 4As shown, in some embodiments, the buck-boost power converter 400 may further include an integrated operational amplifier OPA. Among them, the non-inverting input terminal of the integrated operational amplifier OPA is connected to the first terminal of the heating element resistance detection resistor Rs, and the inverting input terminal is connected to the second terminal of the heating element resistance detection resistor Rs. In this case, the microcontroller MCU may also be configured to detect the output voltage of the integrated operational amplifier OPA, thereby detecting the voltage across the heating element resistance detection resistor Rs.

[0027] As Figure 4 shown, in some embodiments, the buck-boost power switch Q1 may be implemented by, including but not limited to, an N-type metal oxide semiconductor field effect transistor NMOS, a P-type metal oxide semiconductor field effect transistor PMOS, etc., and the buck-boost power switch Q2 may be implemented by, including but not limited to, an N-type metal oxide semiconductor field effect transistor NMOS, a P-type metal oxide semiconductor field effect transistor PMOS, and a Schottky diode, etc.

[0028] As Figure 4 shown, in some embodiments, the microcontroller MCU provides a square wave signal with a fixed period T and a duty cycle D to the drive circuit 402 via the general-purpose input / output port GPIO, where D = (the duration Ton when Q1 is in the on state in the fixed period T) / T. The drive circuit 402 receives the square wave signal output by the microcontroller MCU via the general-purpose input / output port GPIO and converts the square wave signal into drive signals DR1 and DR2 with opposite phases to drive the buck-boost power switches Q1 and Q2 to conduct alternately, thereby converting the battery voltage V1 of the lithium battery DC into the voltage V4 = -V1×D(1 - D) across the capacitor C. Note that V4 is a negative voltage. Here, since the resistance value of the heating element resistance detection resistor Rs is more than 100 times smaller than the resistance value of the heating element R, the voltage across the heating element resistance detection resistor Rs can be ignored. Therefore, the voltage V4 across the capacitor C is also the voltage across the heating element R (i.e., the output voltage of the buck-boost power converter 400).

[0029] As Figure 4As shown, in some embodiments, the levels of drive signals DR1 and DR2 are related to the types of switching transistors for implementing the buck-boost power switching transistors Q1 and Q2. If NMOS is used as the buck-boost power switching transistor Q1 / Q2, then when the drive signal DR1 / DR2 is at a high level, the buck-boost power switching transistor Q1 / Q2 is in the on state, and when the drive signal DR1 / DR2 is at a low level, the buck-boost power switching transistor Q1 / Q2 is in the off state. If PMOS is used as the buck-boost power switching transistor Q1 / Q2, then when the drive signal DR1 / DR2 is at a low level, the buck-boost power switching transistor Q1 / Q2 is in the on state, and when the drive signal DR1 / DR2 is at a high level, the buck-boost power switching transistor Q1 / D2 is in the off state. If a diode is used as the buck-boost power switching transistor Q2, then due to the reverse cut-off characteristic of the diode, the drive signal DR2 can be omitted.

[0030] As Figure 4 shown, in some embodiments, the effective level at the general-purpose input / output port GPIO represents the level when the buck-boost power switching transistor Q1 is in the on state. If the level at the general-purpose input / output port GPIO (abbreviated as the GPIO level) is active high, then under different switching transistor type conditions, the levels of the drive signals DR1 and DR2 are as shown in Table 1. If the GPIO level is active low, then under different switching transistor type conditions, the levels of the drive signals DR1 and DR2 are as shown in Table 2.

[0031] Table 1

[0032] GPIO Level Type of Q1 Switch Type of Q2 Switch DR1 Drive Signal DR2 Drive Signal High NMOS NMOS High Low Low NMOS NMOS Low High High PMOS PMOS Low High Low PMOS PMOS High Low High NMOS PMOS High High Low NMOS PMOS Low Low High PMOS NMOS Low Low Low PMOS NMOS High High High NMOS DIODE High / Low NMOS DIODE Low / High PMOS DIODE Low / Low PMOS DIODE High /

[0033] Table 2

[0034]

[0035]

[0036] For example, when the effective level for driving the buck-boost power switching transistors Q1 and Q2 to conduct is high, when the driving signal DR1 is high, the driving signal DR2 is low, the buck-boost power switching transistor Q1 is in the conducting state, and the buck-boost power switching transistor Q2 is in the off state; when the driving signal DR1 is low, the driving signal DR2 is high, the buck-boost power switching transistor Q1 is in the off state, and the buck-boost power switching transistor Q2 is in the conducting state. Conversely, when the effective level for driving the buck-boost power switching transistors Q1 and Q2 to conduct is low, when the driving signal DR1 is low, the driving signal DR2 is high, the buck-boost power switching transistor Q1 is in the conducting state, and the buck-boost power switching transistor Q2 is in the off state; when the driving signal DR1 is high, the driving signal DR2 is low, the buck-boost power switching transistor Q1 is in the off state, and the buck-boost power switching transistor Q2 is in the conducting state.

[0037] As Figure 4 shown, in some embodiments, the microcontroller MCU detects the battery voltage V1 of the lithium battery DC through the analog-to-digital conversion module ADC1. Given that the target output voltage VT of the buck-boost power converter 400 is known, the microcontroller MCU can calculate the duty cycle D by dividing the absolute value of the target output voltage VT of the buck-boost power converter 400 by the sum of the absolute value of the target output voltage VT of the buck-boost power converter 400 and the absolute value of the battery voltage V1 of the lithium battery DC, that is, D = |VT| / (|VT| + |V1|). The microcontroller MCU outputs a square wave signal with a fixed period T and a duty cycle D = D = |VT| / (|VT| + |V1|) via the general-purpose input / output port GPIO, which can make the output voltage V4 of the buck-boost power converter 400 reach the target output voltage VT, note that VT is a negative voltage.

[0038] As Figure 4As shown, in some embodiments, the microcontroller MCU detects a voltage V5 related to the output voltage V4 of the buck-boost power converter 400 through the analog-to-digital conversion module ADC2. According to Kirchhoff's law, V5 = [VREF×R2 / (R1 + R2)+V4×R1 / (R1 + R2)], where, since the analog-to-digital conversion module ADC2 can only detect positive voltages, there is a constraint here that V5>0, requiring the ratio of the resistance value of the output voltage detection resistor R2 to the resistance value of the output voltage detection resistor R1 to be greater than the ratio of the absolute value of the output voltage V4 of the buck-boost power converter 400 to the reference voltage VREF provided by the reference voltage source 404, that is, R2 / R1>(-V4 / VREF). Thus, the microcontroller MCU can inversely deduce the voltage across the heating element R, that is, the output voltage V4 of the buck-boost power converter 400 = [(R1 + R2)×V5 / R1 - VREF×R2 / R1] (since the resistance value of the heating element resistance detection resistor Rs is more than 100 times smaller than the resistance value of the heating element R, the voltage across the heating element resistance detection resistor Rs is negligible).

[0039] As Figure 4 shown, in some embodiments, the heating element resistance detection resistor Rs is connected in series with the heating element R, and the current I flowing through the heating element R also flows through the heating element resistance detection resistor Rs. The voltage ΔV across the heating element resistance detection resistor Rs = I×Rs. The connection point between the heating element resistance detection resistor Rs and the heating element R is connected to the inverting input terminal of the integrated operational amplifier OPA; the connection point between the heating element resistance detection resistor Rs and the ground (GND) is connected to the non-inverting input terminal of the integrated operational amplifier OPA. The gain of the integrated operational amplifier OPA is G, and the integrated operational amplifier OPA amplifies the voltage ΔV across the heating element resistance detection resistor Rs to V6 = ΔV×G = I×Rs×G. The microcontroller MCU detects the voltage V6 output by the integrated operational amplifier OPA through the analog-to-digital converter ADC3, and thus can inversely deduce the current I flowing through the heating element R = V6 / Rs / G.

[0040] As Figure 4 shown, in some embodiments, the microcontroller MCU can inversely deduce the resistance value R of the heating element R = V4 / I = [(R1 + R2)×V5 / R1 - VREF×R2 / R1] / (V6 / Rs / G). Since the temperature of the heating element R corresponds one-to-one with the resistance value, detecting the resistance value of the heating element R can obtain the actual temperature of the heating element R. The microcontroller MCU can increase or decrease the output voltage V4 of the buck-boost power converter 400 according to the comparison result between the target temperature and the actual temperature of the heating element R, so as to control the heating element R to reach the target temperature.

[0041] Figure 5 FIG. shows a schematic circuit diagram of an exemplary implementation of a buck-boost power converter used in a heat-not-burn electric heating atomization and vaporization device according to an embodiment of the present invention. InFigure 5 In the illustrated exemplary implementation, the buck-boost power switch Q1 is implemented using a P-type metal-oxide-semiconductor field-effect transistor (PMOS), and the buck-boost power switch Q2 is implemented using a diode. Since the diode has a reverse cutoff characteristic, the drive signal DR2 can be omitted.

[0042] The present invention may be embodied in other specific forms without departing from its spirit and essential characteristics. For example, the algorithms described in specific embodiments may be modified without departing from the basic spirit of the present invention in terms of system architecture. Therefore, the current embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning and equivalents of the claims are thus included within the scope of the present invention.

Claims

1. A power converter used in a heat-not-burn electric heating atomization and vaporization device, comprising a microcontroller, a drive circuit, a first buck-boost power switch transistor, a second buck-boost power switch transistor, and a buck-boost inductor. The first terminal of the first buck-boost power switch transistor is used to connect to the positive electrode of a lithium battery, and the second terminal is connected to the first terminal of the second buck-boost power switch transistor and the first terminal of the buck-boost inductor. The second terminal of the second buck-boost power switch transistor is used to connect to the first terminal of a heating element, and the second terminal of the buck-boost inductor is grounded. Wherein: The microcontroller is configured to detect the battery voltage of the lithium battery, calculate the duty cycle of a square wave signal based on the battery voltage of the lithium battery and the target output voltage of the power converter, and provide the square wave signal to the drive circuit; The drive circuit is configured to receive the square wave signal and generate at least one of a first drive signal for the first buck-boost power switch transistor and a second drive signal for the second buck-boost power switch transistor based on the square wave signal, so that the first buck-boost power switch transistor and the second buck-boost power switch transistor conduct alternately.

2. The power converter according to claim 1, wherein, The microcontroller is further configured to calculate the duty cycle of the square wave signal by dividing the absolute value of the target output voltage of the power converter by the sum of the absolute value of the target output voltage of the power converter and the absolute value of the battery voltage of the lithium battery.

3. The power converter according to claim 1, further comprising a capacitor. The first terminal of the capacitor is connected to the second terminal of the second buck-boost power switch transistor, and the second terminal is grounded.

4. The power converter according to claim 1, further comprising a reference voltage source, a first output voltage detection resistor, and a second output voltage detection resistor. The first terminal of the first output voltage detection resistor is connected to the reference voltage source, and the second terminal is connected to the first terminal of the second output voltage detection resistor. The second terminal of the second output voltage detection resistor is connected to the second terminal of the second buck-boost power switch transistor.

5. The power converter according to claim 4, wherein, The microcontroller is further configured to detect the voltage at the connection point between the first output voltage detection resistor and the second output voltage detection resistor, so as to detect the output voltage of the power converter.

6. The power converter according to claim 5, wherein, The ratio of the resistance value of the second output voltage detection resistor to the resistance value of the first output voltage detection resistor is greater than the ratio of the absolute value of the output voltage of the power converter to the reference voltage provided by the reference voltage source.

7. The power converter according to claim 1, further comprising a heating element resistance detection resistor. The first terminal of the heating element resistance detection resistor is used to connect to the second terminal of the heating element, and the second terminal is grounded.

8. The power converter according to claim 7, further comprising an integrated operational amplifier. The non-inverting input terminal of the integrated operational amplifier is connected to the first terminal of the heating element resistance detection resistor, and the inverting input terminal is connected to the second terminal of the heating element resistance detection resistor.

9. The power converter according to claim 8, wherein, The microcontroller is further configured to detect the output voltage of the integrated operational amplifier, so as to detect the voltage across the resistance detection resistor of the heating element resistance.

10. A heat-not-burn electric heating atomization and gasification device, comprising the power converter according to any one of claims 1 to 9.

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