Automatic compensation airflow detection chip, circuit, assembly and electronic device

Abstract

The invention provides an automatic compensation airflow detection circuit, which comprises a differential amplification unit used for being connected with a resistance bridge and used for receiving the output voltage of the resistance bridge; the adjusting module is connected with the output end of the differential amplification unit and used for adjusting the voltage of the output end of the differential amplification unit when no airflow flows; one input end of the difference value control module is connected with the output end of the adjusting module, a first reference voltage is connected to the other input end of the difference value control module, the difference value control module is used for comparing the voltages of the two input ends, and when the comparison result meets the preset condition, the difference value control module controls the adjusting module to stop adjusting. The embodiment of the invention further provides an airflow detection chip, an airflow detection assembly and an electronic device.

Description

Technical Field

[0001] The present application relates to the technical field of airflow detection, and in particular to an automatic compensation airflow detection chip, circuit, component and electronic device. Background Art

[0002] With the development of heating atomization technology, electronic atomization devices that use electricity to heat atomization have emerged. Electricity is used to heat the atomized liquid. The electronic atomization device is used to heat the liquid and atomize it into an aerosol for the user to inhale. The electronic atomization device may be a medical electronic atomization device, a common electronic atomization device, etc., and the liquid may be, for example, liquid medicine, e-liquid, etc.

[0003] An existing electronic atomization device triggers the power supply to be turned on by pressing a mechanical switch, thereby heating the atomized liquid for the user to inhale. This method has a low cost, but since it requires the user to perform additional manual operations, it does not conform to the user's usage habits and brings inconvenience to the user.

[0004] Another existing electronic atomization device uses a capacitor microphone to trigger the power supply. The specific principle is to use two diaphragms to form a capacitor, one of which changes with the airflow, and the other does not move. When inhaling, the air inside the electronic atomization device forms a negative pressure, which causes the distance between the two diaphragms to change, resulting in a change in the capacitance value. The detection circuit of the electronic atomization device controls whether to atomize the liquid by detecting the change in capacitance value. This type of electronic atomization device conforms to the user's usage habits, but the structural design is complex and the material cost is high. In addition, when the liquid leaks after the electronic atomization device has been used for a long time, the liquid contaminates the variable membrane, affecting the change in capacitance value, and is prone to false triggering and causing dangerous accidents.

[0005] The applicant's prior Chinese application number CN202311127344.4 applied for an airflow detection circuit, which is used in conjunction with a resistor bridge to replace the capacitor microphone solution. Even if the resistor bridge is contaminated, the impact of this solution is relatively small. However, since the resistor bridge and the airflow detection circuit are large in size and have manufacturing errors, especially the resistor bridge, there is a certain probability that the airflow detection circuit will misjudge that there is airflow even when there is no airflow, resulting in false triggering, which in turn leads to subsequent control errors. Summary of the invention

[0006] The technical problem to be solved by the embodiments of the present application is to provide an automatic compensation airflow detection chip, circuit, component and electronic device to address the deficiencies of the prior art. Automatic compensation can be performed to reduce the probability of misjudgment of the airflow detection circuit.

[0007] In order to solve the above technical problems, the first aspect of the embodiment of the present application provides an automatic compensation airflow detection circuit, including:

[0008] A differential amplifier unit, which is used to be connected to the resistance bridge and is used to receive the output voltage of the resistance bridge;

[0009] A regulating module connected to the output end of the differential amplification unit and used for regulating the voltage at the output end of the differential amplification unit when there is no airflow;

[0010] The difference control module has one input end connected to the output end of the regulating module and another input end connected to the first reference voltage. The difference control module is used to compare the voltages of the two input ends. When the comparison result meets the preset conditions, the difference control module controls the regulating module to stop regulating.

[0011] Optionally, the adjustment module includes an addition and subtraction unit, a compensation generating unit and an operation judgment unit, wherein the addition and subtraction unit is respectively connected to the differential amplification unit, the operation judgment unit and the compensation generating unit, the operation judgment unit and the compensation generating unit are both connected to the difference control module, the operation judgment unit controls the addition and subtraction unit to perform addition or subtraction operations according to the signal of the difference control module, the compensation generating unit is used to generate a compensation value, and the addition and subtraction unit receives the signal of the operation judgment unit to add or subtract the voltage at the output end of the differential amplification unit from the compensation value.

[0012] Optionally, after the airflow detection circuit is powered on, the calculation judgment unit controls the addition and subtraction unit to perform addition or subtraction and maintain it according to the signal of the difference control module.

[0013] Optionally, the operation judgment unit includes a first edge trigger and a second edge trigger, wherein the first input end of the first edge trigger and the first input end of the second edge trigger are used to receive a reset signal, the second input end of the first edge trigger and the second input end of the second edge trigger are both connected to the difference control module, and the second input end of the first edge trigger receives a signal opposite to the signal received by the second input end of the second edge trigger, the output end of the first edge trigger is connected to the addition and subtraction unit, and the output end of the second edge trigger is connected to the addition and subtraction unit, and the first edge trigger and the second edge trigger are triggered when they receive a reset signal, and the first edge trigger and the second edge trigger control the addition and subtraction unit to perform addition or subtraction operations according to the signal output by the difference control module; or,

[0014] The operation judgment unit includes an edge trigger and a first inverter, wherein the first input end of the edge trigger is used to receive a reset signal, the second input end of the edge trigger is connected to the difference control module, the output end of the edge trigger is connected to the addition and subtraction unit, and the output end of the edge trigger is also connected to the addition and subtraction unit via the first inverter. When the edge trigger receives the reset signal, it is triggered, and the edge trigger controls the addition and subtraction unit to perform addition or subtraction operations according to the signal output by the difference control module.

[0015] Optionally, the addition and subtraction unit includes an addition and subtraction control subunit and an operator unit, wherein the control end of the addition and subtraction control subunit is connected to the operation judgment unit, the input end of the addition and subtraction control subunit is respectively connected to the compensation generating unit and the system grounding end, the output end of the addition and subtraction control subunit is connected to the operator unit, and the operator unit is also connected to the output end of the differential amplifier unit. When the operation judgment unit controls the addition and subtraction control subunit to operate in a first state, the operator unit adds the voltage at the output end of the differential amplifier unit to the compensation value output by the compensation generating unit; when the operation judgment unit controls the addition and subtraction control subunit to operate in a second state, the operator unit subtracts the voltage at the output end of the differential amplifier unit from the compensation value output by the compensation generating unit.

[0016] Optionally, the addition and subtraction control subunit includes a fourth switch, a fifth switch, a third switch and a sixth switch, and the operation subunit includes a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor, wherein the control end of the fourth switch and the control end of the fifth switch are connected to the operation judgment unit and receive the same signal, the control end of the third switch and the control end of the sixth switch are connected to the operation judgment unit and receive the same signal, the input end of the fourth switch and the input end of the sixth switch are both connected to the system ground end, the output end of the fourth switch is connected to the second end of the first operational amplifier via the seventh resistor, and the output end of the sixth switch is connected to the first operational amplifier via the fifth resistor. The first terminal of the differential amplifier is connected to the first terminal of the differential amplifier via the sixth resistor, the second terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier via the eighth resistor, and the third switch and the compensation generating unit are connected to the first terminal of the differential amplifier via the eighth resistor. When the fourth switch and the fifth switch are turned on, the third switch and the sixth switch are turned off; when the third switch and the sixth switch are turned on, the fourth switch and the fifth switch are turned off.

[0017] Optionally, the compensation generating unit includes a counting subunit and a digital-to-analog converter, wherein the counting subunit is connected to the difference control module, and the counting subunit is also used to receive a reset signal. When the counting subunit receives the reset signal, it starts counting, and when the counting subunit receives a stop counting signal output by the difference control module, it stops counting. The digital-to-analog converter is connected to the counting subunit, and the digital-to-analog converter is used to convert the current count value of the counting subunit into a voltage value, and the voltage value is used to output to the addition and subtraction unit.

[0018] Optionally, the counting subunit includes an oscillator and a counter, and the compensation generating unit also includes a voltage follower, wherein the counter is respectively connected to the oscillator and the difference control module, and the counter is also used to receive a reset signal, and the counter is connected to the digital-to-analog converter, and the output end of the digital-to-analog converter is connected to the voltage follower, and the voltage follower outputs the compensation value to the addition and subtraction unit.

[0019] Optionally, the preset condition is that the difference between the voltages at the two input terminals of the difference control module is less than or equal to a preset number of step voltages, wherein the step voltage is the voltage accuracy of the digital-to-analog converter and the preset number is a positive number.

[0020] Optionally, the difference control module includes a voltage comparator and an adjustment control unit, wherein the first end of the voltage comparator is connected to the first reference voltage, the second end of the voltage comparator is connected to the output end of the adjustment module, the output end of the voltage comparator is connected to the adjustment module, the output end of the voltage comparator is also connected to the adjustment control unit, and the output end of the adjustment control module is connected to the adjustment module;

[0021] Wherein, when the voltage at the second end of the voltage comparator is greater than the voltage at its first end, the difference control module controls the adjustment module so that the voltage at the output end of the adjustment module is less than the voltage at its input end; when the voltage at the second end of the voltage comparator is less than the voltage at its first end, the difference control module controls the adjustment module so that the voltage at the output end of the adjustment module is greater than the voltage at its input end; when the output level of the voltage comparator changes, the adjustment control module controls the adjustment module to stop adjustment.

[0022] Optionally, the regulation control unit includes a third edge trigger, a fourth edge trigger and a first logic gate unit, wherein the first end of the third edge trigger and the first end of the fourth edge trigger are both connected to the output end of the voltage comparator, the second end of the third edge trigger and the second end of the fourth edge trigger are both connected to the system power supply end, the output end of the third edge trigger and the output end of the fourth edge trigger are respectively connected to the first logic gate unit, and one of the third edge trigger and the fourth edge trigger is a rising edge trigger, and the other is a falling edge trigger, the output end of the first logic gate unit is connected to the regulation module, and the third edge trigger and the fourth edge trigger are also used to receive a reset signal.

[0023] Optionally, the airflow detection circuit further includes an amplifying bias unit and a reference bias unit, wherein the amplifying bias unit is connected to the regulating module and the difference control module respectively, the amplifying bias unit is used to amplify the voltage output by the regulating module and output it to the input end of the difference control module after superimposing the second bias voltage, and the reference bias unit is connected to the difference control module, and the reference bias unit is used to output the first reference voltage after superimposing the second bias voltage to the input end of the difference control module; or,

[0024] The airflow detection circuit also includes a second bias unit and a reference bias unit, wherein the second bias unit is connected to the adjustment module and the difference control module respectively, and the second bias unit is used to superimpose the voltage output by the adjustment module with the second bias voltage and output it to the input end of the difference control module, and the reference bias unit is connected to the difference control module, and the reference bias unit is used to superimpose the first reference voltage with the second bias voltage and output it to the input end of the difference control module.

[0025] Optionally, the differential amplifier unit is used to subtract the voltages at its two input terminals, amplify the voltages, superimpose the voltages at the first bias voltage, and then output the voltages to the adjustment module. The airflow detection circuit is also designed to subtract the first bias voltage from the voltage at the output terminal of the adjustment module and then output the voltage to the input terminal of the difference control module.

[0026] Optionally, the airflow detection circuit also includes a state selection unit, the input of the state selection unit is respectively connected to a first reference voltage and an airflow threshold voltage, the output end of the state selection unit is connected to the input end of the difference control module, the state selection unit is used to select the first reference voltage or the airflow threshold voltage output, when the airflow detection circuit is powered on, the state selection unit selects the first reference voltage output, when the comparison result meets a preset condition, the state selection unit selects the airflow threshold voltage output to monitor the airflow, wherein the first reference voltage is less than the airflow threshold voltage.

[0027] Optionally, the airflow detection circuit further includes a second inverter, a second logic gate unit, a delay unit and a logic control unit, wherein the input end of the second inverter is connected to the output end of the difference control module, the output end of the second inverter is connected to an input end of the second logic gate unit, the difference control module is connected to the other input end of the second logic gate unit via the delay unit, and the output end of the logic gate unit is connected to the logic control unit;

[0028] The state selection unit includes a first switch and a second switch, wherein the control end of the first switch is connected to the output end of the second inverter, the input end of the first switch is connected to the airflow threshold voltage, the output end of the first switch is connected to the input end of the difference control module, the control end of the second switch is connected to the output end of the difference control module, the input end of the second switch is connected to the first reference voltage, and the output end of the second switch is connected to the input end of the difference control module.

[0029] A second aspect of an embodiment of the present application provides an airflow detection component, comprising:

[0030] a resistance bridge configured such that the flow of airflow causes a change in resistance, and when the resistance bridge is powered, the resistance bridge is configured to cause a change in output voltage based on the change in resistance;

[0031] The above-mentioned airflow detection circuit is connected to the resistance bridge.

[0032] A third aspect of an embodiment of the present application provides an electronic device, including:

[0033] power supply;

[0034] The above-mentioned airflow detection component or the above-mentioned airflow detection circuit, wherein the airflow detection circuit is connected to the power supply.

[0035] A fourth aspect of the embodiments of the present application provides an automatic compensation airflow detection chip, which is used to be connected to a resistance bridge, including:

[0036] A differential amplifier unit, which is used to be connected to the resistance bridge and is used to receive the output voltage of the resistance bridge;

[0037] A regulating module connected to the output end of the differential amplification unit and used for regulating the voltage at the output end of the differential amplification unit when there is no airflow;

[0038] The difference control module has one input end connected to the output end of the regulating module and another input end connected to the first reference voltage. The difference control module is used to compare the voltages of the two input ends. When the comparison result meets the preset conditions, the difference control module controls the regulating module to stop regulating.

[0039] The embodiment of the present application sets a regulating module and a difference control module, wherein the regulating module is connected to the output end of the differential amplifier unit, and is also used to regulate the voltage at the output end of the differential amplifier unit when there is no airflow. One input end of the difference control module is connected to the output end of the regulating module, and the other input end thereof is connected to a first reference voltage. The difference control module is used to compare the voltages of the two input ends, and when the comparison result meets the preset conditions, the difference control module controls the regulating module to stop regulating. By such a setting, even if the output voltage of the resistor bridge, the differential amplifier unit, etc. deviates too much from the first reference voltage due to manufacturing errors when there is no airflow, the regulating module can automatically adjust the deviated voltage, and compare the output voltage adjusted by the regulating module with the first reference voltage, and when the comparison result meets the preset conditions, the regulating module is controlled to stop regulating, thereby ensuring that the airflow detection circuit will not be triggered by mistake after adjustment when there is no airflow, and thus will not cause erroneous operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 is a circuit module diagram of an electronic device according to a first embodiment of the present application;

[0042] Figure 2 is a detailed circuit module diagram of the airflow detection circuit of the first embodiment of the present application;

[0043] Figure 3 It is a detailed circuit module diagram of the airflow detection circuit of the second embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] The terms "including" and "having" and any variations thereof appearing in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units that are inherent to these processes, methods, products or devices. In addition, the terms "first", "second" and "third" are used to distinguish different objects, rather than to describe a specific order. The connection of this application includes direct connection and indirect connection. Indirect connection means that other electronic components, pins, etc. may exist between the two connected components. The XX pin mentioned in this application may be an actual pin, or it may not be an actual pin, for example, it is only a pin of a component or a pin of a wire. The three situations mentioned and / or included in this application, such as A and / or B, include the three situations of A, B, A and B.

[0046] First embodiment

[0047] See also Figure 1 , the embodiment of the present application provides an electronic device, the electronic device is, for example, an electronic atomization device, the electronic atomization device is, for example, a medical electronic atomization device, a common electronic atomization device, or other device that needs to heat liquid, and the electronic atomization device uses electricity to heat the liquid and atomize it into an aerosol for the user to inhale. This embodiment is described by taking the electronic device as an electronic atomization device as an example, but the electronic device of the present application is not limited to being an electronic atomization device, and can also be other electronic devices.

[0048] In this embodiment, the electronic atomization device includes a heating component and a power supply control component, and the heating component and the power supply control component can be detachably connected or non-detachably connected. The detachable connection, for example, the heating component and the power supply control component can be plugged in, magnetically connected, or screwed together, and the heating component can be separated from the power supply control component to separate the two. At this time, the heating component can be replaced with a new one as needed, and the power supply control component can be shared, which can save costs; the non-detachable connection means that the heating component cannot be replaced, and the heating component is directly electrically connected to the power supply control component.

[0049] In this embodiment, the heating component includes an atomizing element R0, and the heating component stores liquid inside. The atomizing element R0 is in contact with the liquid. The atomizing element R0 is, for example, a heating wire, a heating wire, a ceramic core including a heating wire or a heating wire and a ceramic seat, a cotton core including a heating wire or a heating wire and fiber cotton, or other conventional atomizing elements R0. The atomizing element R0 is powered to heat and atomize the liquid, thereby generating an aerosol for the user to inhale.

[0050] In this embodiment, the power supply control component includes a power supply 110, a resistance bridge 200, and an airflow detection circuit. The power supply 110 can be a battery, an AC-DC converter, a DC-DC converter, etc., preferably a battery ( Figure 1 The resistance bridge 200 is configured such that the flow of airflow causes a change in resistance. One implementation of the resistance bridge 200 is a Wheatstone bridge. Specifically, the resistance bridge 200 includes four resistors, namely a first resistor R21, a second resistor R22, a third resistor R23, and a fourth resistor R24. The first resistor R21 is connected in series with the second resistor R22, the third resistor R23 is connected in series with the fourth resistor R24, and a branch formed by the first resistor R21 and the second resistor R22 in series and a branch formed by the third resistor R23 and the fourth resistor R24 ​​in series are connected in parallel. One of the four resistors is related to the airflow. In this embodiment, The resistor is described by taking the third resistor R23 as an example. When the airflow flows through the third resistor R23, the resistance value of the third resistor R23 will change, and the total resistance of the resistor bridge 200 will also change. For example, when there is no airflow or the airflow is very small, the resistance value of the third resistor R23 is the standard resistance value. When the user sucks and the air pressure at the third resistor R23 decreases, the resistance value of the third resistor R23 will increase, for example, relative to the standard resistance value. When the user blows and the air pressure at the third resistor R23 increases, the resistance value of the third resistor R23 will decrease, for example, relative to the standard resistance value (this embodiment is described as an example), or the relationship between the resistance value and the air pressure change is reversed. The present application determines whether it is sucking, blowing, or no airflow by detecting the change in the resistance value of the third resistor R23. The corresponding states are the sucking state, the blowing state, and the unused state, wherein the blowing state and the unused state constitute the unsucking state. In addition, in other embodiments of the present application, the resistance of the third resistor R23 does not change with the airflow, and the resistance of one of the first resistor R21, the second resistor R22, and the fourth resistor R24 ​​may change with the airflow. Those skilled in the art may adjust the corresponding relationship as needed. In addition, in other embodiments of the present application, the four resistors of the resistance bridge 200 may also be multiple resistors whose resistance changes with the airflow. For a specific description, please refer to the applicant's prior application CN202322604975.2. The content of the prior patent application is also introduced into this application as the content of this application, and will not be repeated here.

[0051] In order to detect the resistance change of the third resistor R23, in the present embodiment, when the electronic atomization device is in an unused state (no airflow), the ratio of the resistance of the first resistor R21 to the resistance of the second resistor R22 is equal to the ratio of the resistance of the third resistor R23 to the resistance of the fourth resistor R24. When the electronic atomization device is in a puffing state, since the resistance of the first resistor R21, the second resistor R22, and the fourth resistor R24 ​​are almost unchanged, the resistance of the third resistor R23 will increase relative to the standard resistance due to the airflow. , resulting in the ratio of the resistance value of the first resistor R21 to the resistance value of the second resistor R22 being smaller than the ratio of the resistance value of the third resistor R23 to the resistance value of the fourth resistor R24. When the electronic atomization device is in the blowing state, since the resistance values ​​of the first resistor R21, the second resistor R22, and the fourth resistor R24 ​​are almost unchanged, the resistance value of the third resistor R23 will decrease relative to the standard resistance value, resulting in the ratio of the resistance value of the first resistor R21 to the resistance value of the second resistor R22 being greater than the ratio of the resistance value of the third resistor R23 to the resistance value of the fourth resistor R24.

[0052] Since the change of the resistance value itself is difficult to measure, the present application converts the resistance change into a voltage change for measurement. Specifically, in the present embodiment, the resistance bridge 200 also includes a bridge power supply terminal VDD, a bridge ground terminal VSS, a first voltage output terminal Vout1 and a second voltage output terminal Vout2, wherein the connection point where the first resistor R21 and the third resistor R23 are connected is called a first connection point, the first connection point is connected to the bridge power supply terminal VDD, the connection point where the second resistor R22 and the fourth resistor R24 ​​are connected is called a second connection point, the second connection point is connected to the bridge ground terminal VSS, the connection point where the first resistor R21 and the second resistor R22 are connected is called a third connection point, the third connection point is connected to the first voltage output terminal Vout1, the connection point where the third resistor R23 and the fourth resistor R24 ​​are connected is called a fourth connection point, and the fourth connection point is connected to the second voltage output terminal Vout2.

[0053] In this embodiment, the airflow detection circuit includes a system power supply terminal VBAT+, a system ground terminal VBAT-, a voltage input terminal, and a resistor power supply terminal. Among them, the system power supply terminal VBAT+ is connected to the positive terminal of the power supply 110, and the system ground terminal VBAT- is connected to the negative terminal of the power supply 110. The number of resistor power supply terminals can be one or two. When it is one, the resistor power supply terminal is connected to one of the bridge power supply terminal VDD and the bridge ground terminal VSS of the resistor bridge 200, and the other of the bridge power supply terminal VDD and the bridge ground terminal VSS is connected to the system power supply terminal VBAT+ or the system ground terminal VBAT-. When the number of resistor power supply terminals is two, the two resistor power supply terminals are called the first resistor R21 power supply terminal and the second resistor R22 power supply terminal. The first resistor R21 power supply terminal is connected to the bridge power supply terminal VDD, and the second resistor R22 power supply terminal is connected to the bridge ground terminal VSS. This embodiment is described by taking the number of resistor power supply terminals as one as an example. In this embodiment, the resistor power supply terminal is connected to the bridge power supply terminal VDD, and the bridge ground terminal VSS is connected to the system ground terminal VBAT-. In this embodiment, the number of voltage input terminals is two, and the two voltage input terminals are called the first voltage input terminal Vin1 and the second voltage input terminal Vin2, wherein the first voltage input terminal Vin1 is connected to the first voltage output terminal Vout1 of the resistor bridge 200, and the second voltage input terminal Vin2 is connected to the second voltage output terminal Vout2 of the resistor bridge 200, and the voltage difference between the first voltage output terminal Vout1 and the second voltage output terminal Vout2 is the output voltage. In addition, in other embodiments of the present application, the number of voltage input terminals can also be one, in which case the voltage input terminal is connected to the second voltage output terminal Vout2 (the resistor bridge 200 includes a solution of two resistors), and the voltage of the second voltage output terminal Vout2 is the output voltage. In this embodiment, the connection relationship between the system power supply terminal VBAT+ and the resistor power supply terminal, and the connection relationship between the resistor power supply terminal and the system ground terminal VBAT- can refer to the applicant's prior application CN202311127344.4, the content of which is also introduced into this application as the content of this application, and will not be repeated here.

[0054] Please continue to see Figure 1 In this embodiment, the airflow detection circuit further includes a differential amplifier unit 120, a logic control unit 130 and a power switch M1, wherein the differential amplifier unit 120 is connected to the first voltage input terminal Vin1 and the second voltage input terminal Vin2 respectively to receive the output voltage of the resistance bridge 200, and the differential amplifier unit 120 is used to perform a subtraction operation on the voltages of the first voltage input terminal Vin1 and the second voltage input terminal Vin2 and amplify the result of the operation. In this embodiment, the output voltage of the output terminal of the differential amplifier unit 120 is:

[0055] V1=Vp1+X*(VA-VB);

[0056] Among them, V1 is the output voltage of the differential amplifier unit 120; VA is the voltage of the first input terminal, VB is the voltage of the second voltage input terminal Vin2, X is the first amplification factor, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, etc., X is a positive number greater than 1, Vp1 is the first bias voltage, Vp1 can be VA or VB, or other voltages. In this embodiment, Vp1 is equal to VA.

[0057] In this embodiment, by setting the first bias voltage, the first bias voltage is a positive voltage, so that the output voltage of the differential amplifier unit 120 can be close to the middle value of the power supply voltage. It is best that the output voltage of the differential amplifier unit 120 is not too low or too high. This process is convenient for the design of the subsequent circuit, and can prevent the output voltage of the differential amplifier unit 120 from being negative. Negative values ​​will increase the difficulty of the design of the subsequent circuit. Positive values ​​are conducive to the design of the circuit and have low cost. In addition, in other embodiments of the present application, the first bias voltage may not be increased. At this time, the output voltage of the differential amplifier unit 120 is X*(VA-VB).

[0058] In this embodiment, the logic control unit 130 is indirectly connected to the differential amplifier unit 120, the output end of the logic control unit 130 is connected to the control end of the power switch M1, the first end of the power switch M1 is connected to the system power supply end VBAT+ or the system ground end VBAT-, the second end of the power switch M1 is connected to one end of the atomizing element R0 through the atomizing end AT, and the other end of the atomizing element R0 is correspondingly connected to the negative end of the power supply 110 or the positive end of the power supply 110. When the logic control unit 130 receives a suction signal indicating that the resistance bridge 200 is in a suction state, the logic control unit 130 controls the power switch M1 to be continuously turned on or intermittently turned on.

[0059] In this embodiment, when the power supply 110 does not supply power to the resistance bridge 200, the voltage output by the first voltage output terminal Vout1 is, for example, the voltage of the system ground terminal VBAT- or the voltage of the system power terminal VBAT+, and the voltage output by the second voltage output terminal Vout2 is, for example, also the voltage of the system ground terminal VBAT- or the voltage of the system power terminal VBAT+. At this time, the voltage difference between the first voltage input terminal Vin1 and the second voltage input terminal Vin2 is 0, and there is no current in the resistance bridge 200. When the power supply 110 supplies power to the resistance bridge 200, there is current in the resistance bridge 200, and the voltage output by the first voltage output terminal Vout1 is as follows:

[0060] VA = VD*R1 / (R1+R2);

[0061] Wherein, VA is the voltage outputted by the first voltage output terminal Vout1, VD is the voltage at the bridge power supply terminal VDD, R1 is the resistance value of the first resistor R21, and R2 is the resistance value of the second resistor R22.

[0062] At this time, the voltage of the second voltage output terminal Vout2 is as follows:

[0063] VD*R3 / (R3+R4);

[0064] Wherein, VB is the voltage outputted by the second voltage output terminal Vout2, VD is the voltage at the bridge power supply terminal VDD, R3 is the resistance value of the third resistor R23, and R4 is the resistance value of the fourth resistor R24.

[0065] In an ideal state, since R1 / R2=R3 / R4, when there is no airflow,

[0066] VD*R1 / (R1+R2)=VD*R3 / (R3+R4), that is, VA=VB, so that the voltage output by the first voltage output terminal Vout1 is equal to the voltage output by the second voltage output terminal Vout2. At this time, the voltage difference between the first voltage input terminal Vin1 and the second voltage input terminal Vin2 is 0. When airflow flows, the resistance value of the third resistor R23 will change, and the resistance value will increase or decrease. At this time, VD*R1 / (R1+R2) is not equal to VD*R3 / (R3+R4). Therefore, this embodiment determines whether the resistance bridge 200 is in the suction state or the non-suction state by detecting the voltage difference between the first voltage input terminal Vin1 and the second voltage input terminal Vin2, and the logic control unit 130 controls the power switch M1 and the like according to different states.

[0067] However, in actual situations, due to manufacturing errors of the resistance bridge 200 itself, and / or manufacturing errors of the airflow detection circuit itself (such as the differential amplifier unit 120, the circuit between the differential amplifier unit 120 and the voltage comparator 410 mentioned later, etc.), it may happen that even if there is no airflow, VD*R1 / (R1+R2) and VD*R3 / (R3+R4) are not equal. When the difference between the two exceeds a certain value, for example, after amplification, when it exceeds the airflow threshold voltage mentioned later, the airflow detection circuit will mistakenly determine that there is airflow on the resistance bridge 200, and then control the operation of the atomization element R0, etc., resulting in the electronic atomization device being mistriggered, which will cause the electronic device to malfunction.

[0068] In order to solve the above problems, in the present application, the airflow detection circuit is also designed to be able to perform automatic compensation to prevent the airflow detection circuit from misjudging and mis-triggering. Specifically, in the present embodiment, the airflow detection circuit also includes an adjustment module 300 and a difference control module 400, wherein the input end of the adjustment module 300 is connected to the output end of the differential amplifier unit 120, and the adjustment module 300 is used to adjust and calibrate the voltage at the output end of the differential amplifier unit 120 when there is no airflow, and the second input end of the difference control module 400 is connected to the output end of the adjustment module 300, and its first input end is connected to the first reference voltage Vref, and the difference control module 400 is used to compare the voltages of the two input ends, and when the comparison result meets the preset conditions, the difference control module 400 controls the adjustment module 300 to stop adjusting, and by such a setting, the voltage difference between the two input ends of the difference control module 400 can be reduced when there is no airflow, and the manufacturing error of the circuit before the voltage comparator 410 (mentioned later) can be overcome to cause the misjudgment of the voltage comparator 410.

[0069] Please refer to Figure 1 and Figure 2 In this embodiment, the adjustment module 300 includes an addition and subtraction unit 310, a compensation generating unit 320 and an operation judgment unit 330, wherein the addition and subtraction unit 310 is respectively connected to the output end of the differential amplifier unit 120, the operation judgment unit 330 and the compensation generating unit 320, the addition and subtraction unit 310 is used to perform an addition operation or a subtraction operation on the voltage output from the output end of the differential amplifier unit 120 and the compensation value generated by the compensation generating unit 320, and the compensation value is a dynamic value during the adjustment process, the operation judgment unit 330 is connected to the difference control module 400, and the operation judgment unit 330 controls the addition and subtraction unit 310 to perform an addition operation or a subtraction operation according to the signal of the difference control module 400, and the compensation generating unit 320 is used to generate a dynamic compensation value during the adjustment process, and the compensation value gradually increases and stops changing according to the signal of the difference control module 400. In this embodiment, a reset signal is automatically generated after the electronic device is powered on. When the operation judgment unit 330 receives the reset signal, it controls the addition and subtraction unit 310 to perform addition or subtraction according to the signal of the difference control module 400 and maintains the operation. That is, when the operation judgment unit 330 receives the reset signal, it controls the addition and subtraction unit 310 to perform addition according to the signal of the difference control module 400, and then performs addition. When the operation judgment unit 330 receives the reset signal, it controls the addition and subtraction unit 310 to perform subtraction according to the signal of the difference control module 400, and then performs subtraction. Only when the reset signal is received again at the next power-on, the operation judgment unit 330 will re-determine whether to perform addition or subtraction according to the signal of the difference control module 400.

[0070] Specifically, the operation judgment unit 330 includes a first edge trigger 331, a second edge trigger 332, and a first inverter DV1, wherein the first input end of the first edge trigger 331 and the first input end of the second edge trigger 332 are used to access the reset signal, the second input end of the first edge trigger 331 and the second input end of the second edge trigger 332 are both connected to the difference control module 400, and the second input end of the first edge trigger 331 and the second input end of the second edge trigger 332 receive opposite signals, specifically, the second input end of the second edge trigger 332 is connected to the second input end of the first edge trigger 331 through the first inverter DV1, and the output end of the first edge trigger 331 and the output end of the second edge trigger 332 are connected to the addition and subtraction unit 310. When the first input terminal of the first edge trigger 331 and the second edge trigger 332 do not receive a reset signal, the first edge trigger 331 and the second edge trigger 332 output a preset value (for example, the value retained when the reset signal was received last time or preset to a low level). When the first input terminal of the first edge trigger 331 and the first input terminal of the second edge trigger 332 both receive a reset signal (the reset signal is, for example, a high level), the first edge trigger 331 and the second edge trigger 332 are triggered by a rising edge. At this time, if the difference control module 400 outputs a low level (addition and subtraction control signal), the low level outputs a high level to the first input terminal of the first edge trigger 331 via the first inverter DV1, then The first edge trigger 331 locks and outputs a high level to the addition and subtraction unit 310. The addition and subtraction unit 310 performs an addition operation at this time, for example, which indicates that the voltage difference between the first voltage input terminal Vin1 and the second voltage input terminal Vin2 is smaller than the first reference voltage Vref mentioned later (the first reference voltage is, for example, 0) after amplification; at this time, if the difference control module 400 outputs a high level to the first input terminal of the second edge trigger 332, the second edge trigger 332 locks and outputs a high level to the addition and subtraction unit 310. The addition and subtraction unit 310 performs a subtraction operation, for example, which indicates that the voltage difference between the first voltage input terminal Vin1 and the second voltage input terminal Vin2 is larger than the first reference voltage Vref mentioned later after amplification. In this embodiment, the first edge trigger 331 and the second edge trigger 332 are D triggers and are rising edge triggered. The first input terminals of the first edge trigger 331 and the second edge trigger 332 are CP terminals, and the second input terminals of the first edge trigger 331 and the second edge trigger 332 are D terminals. In addition, in other embodiments of the present application, the first edge trigger 331 and the second edge trigger 332 may also be other edge triggers.

[0071] In this embodiment, the compensation generating unit 320 includes a counting subunit and a digital-to-analog converter 323, wherein the counting subunit is used to receive a reset signal, and the counting subunit is connected to the difference control module 400 and the digital-to-analog converter 323 respectively, and the digital-to-analog converter 323 is used to convert the current count value of the counting subunit into a voltage value, for example, the current count value of the counting subunit is multiplied by the step voltage of the digital-to-analog converter 323 to obtain the converted voltage value, and the voltage value is the compensation value or converted into the compensation value and output to the addition and subtraction unit 310, and the adjacent count values ​​are converted into the compensation value. The voltage obtained after the digital-to-analog conversion differs by a step voltage, and the step voltage is the voltage accuracy of the digital-to-analog converter 323. For example, if the count value is 2 or 3, the voltage obtained after the digital-to-analog conversion differs by a step voltage. The order of magnitude of the step voltage is generally mV, for example, a step voltage is 0.5mV, 1mV, 2mV, 3mV, 4mV, 5mV, 6mV, 7mV, 8mV, 9mV, 10mV, 20mV, 30mV, 40mV, 50mV, etc. This embodiment is described by taking a step voltage of 1mV as an example, and the step voltage can be set as needed. In this embodiment, when the airflow detection circuit is powered on, the counting subunit is reset to zero. When the counting subunit receives a reset signal, the counting subunit is triggered to start counting from 0. When the counting subunit receives a count stop signal from the difference control module 400, the counting subunit stops counting and retains the current count value. Thereafter, the output voltage of the digital-to-analog converter 323 is the current count value*step voltage.

[0072] In this embodiment, the counting subunit includes an oscillator 321 and a counter 322. The counter 322 is connected to the oscillator 321. The edge signal of the oscillator 321 is used to trigger the counter 322 to count. For example, the rising edge or the falling edge is used to trigger the counter 322 to count. The counter 322 is also used to receive a reset signal. The counter 322 is also connected to the difference control module 400 and the digital-to-analog converter 323 respectively. When the electronic device is powered on again, the counter 322 is reset and cleared. Thereafter, the counter 322 receives the reset signal. The counter 322 starts counting from 0 according to the received edge signal trigger. For example, after receiving the reset signal, when the counter 322 receives the rising edge signal output by the oscillator 321 for the first time, the counter 322 counts to 1, and the count is The output voltage of the analog-to-digital converter 323 is 1 mV. When the counter 322 receives the rising edge signal output by the oscillator 321 for the second time, the counter 322 counts to 2, and the output voltage of the digital-to-analog converter 323 is 2 mV. When the counter 322 receives the rising edge signal output by the oscillator 321 for the third time, the counter 322 counts to 3, and the output voltage of the digital-to-analog converter 323 is 3 mV. ..., until the counter 322 receives the counting stop signal output by the difference control module 400, the counter 322 retains the current count value, for example, the current count value is N, N is a positive integer, and the output voltage of the digital-to-analog converter 323 is N*1 mV. Even if the counter 322 receives the rising edge signal again, the count value of the counter 322 will no longer increase, and will still be N, and the output voltage of the digital-to-analog converter 323 will still be N mV. In this embodiment, the compensation generating unit 320 also includes a voltage follower, the input end of the voltage follower is connected to the output end of the digital-to-analog converter 323, and the output end of the voltage follower is connected to the input end of the third switch K3 and the input end of the fifth switch K5 mentioned later, that is, the voltage follower outputs the compensation value. In this embodiment, the implementation of the counter 322 is conventional technology in the art and will not be described in detail here.

[0073] In this embodiment, when the airflow detection circuit is powered on, the counter 322 is reset to zero. When the counter 322 receives the reset signal, the counter 322 starts to count the rising edge or falling edge of the oscillator 321. The value of the counter 322 is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ..., and the digital-to-analog converter 323 is used to convert the current count value of the counter 322 into a corresponding voltage. The voltage follower is used to improve the driving capability of the subsequent circuit and isolate the circuits on both sides to prevent the output voltage of the digital-to-analog converter 323 from being affected by the subsequent circuit. In this embodiment, one implementation of the voltage follower includes a second operational amplifier 324, the same-direction end of the second operational amplifier 324 is connected to the output end of the digital-to-analog converter 323, the reverse end of the second operational amplifier 324 is connected to the output end of the second operational amplifier 324, and the output end of the second operational amplifier 324 is connected to the input end of the third switch K3 and the input end of the fifth switch K5 mentioned later to output the compensation value. In addition, in other embodiments of the present application, the implementation method of the compensation generating unit 320 is not limited to the implementation method of the counter and the digital-to-analog converter described in this embodiment, but can also be other possible implementation methods known to those skilled in the art. In this case, the compensation generating unit 320 can dynamically generate a compensation value, and the compensation value gradually increases. At this time, the step voltage is the difference between two adjacent compensation values.

[0074] In this embodiment, the addition and subtraction unit 310 includes an addition and subtraction control subunit and an operator unit, wherein the control end of the addition and subtraction control subunit is connected to the operation judgment unit 330, specifically, the control end of the addition and subtraction control subunit is respectively connected to the output end of the first edge trigger 331 and the output end of the second edge trigger 332, the input end of the addition and subtraction control subunit is respectively connected to the compensation generating unit 320 and the system ground terminal VBAT-, the output end of the addition and subtraction control subunit is connected to the operator unit, and the operator unit is also connected to the output end of the differential amplifier unit 120. When the operation judgment unit 330 controls the addition and subtraction control subunit to work in the first state, the operator unit adds the voltage at the output end of the differential amplifier unit 120 and the compensation value output by the compensation generating unit 320 and outputs the addition and subtraction control subunit; when the operation judgment unit 330 controls the addition and subtraction control subunit to work in the second state, the operator unit subtracts the voltage at the output end of the differential amplifier unit 120 from the compensation value output by the compensation generating unit 320 and outputs the subtraction control subunit.

[0075] Specifically, in the present embodiment, the addition and subtraction control subunit includes a fourth switch K4, a fifth switch K5, a third switch K3 and a sixth switch K6. The control end of the fourth switch K4 and the control end of the fifth switch K5 are both connected to the output end of the first edge trigger 331, the control end of the third switch K3 and the control end of the sixth switch K6 are both connected to the output end of the second edge trigger 332, the input end of the fourth switch K4 and the input end of the sixth switch K6 are both connected to the system ground terminal VBAT-, the input end of the third switch K3 and the input end of the fifth switch K5 are both connected to the compensation generating unit 320 to access the compensation value, specifically connected to the output end of the voltage follower, and the output ends of the third switch K3 to the sixth switch K6 are all connected to the operation subunit. In this embodiment, the operator unit includes a first operational amplifier 311, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8, wherein the output end of the third switch K3 and the output end of the fourth switch K4 are both connected to the second end of the first operational amplifier 311 through the seventh resistor R7, the second end of the first operational amplifier 311 is connected to the output end of the first operational amplifier 311 via the eighth resistor R8, the output end of the fifth switch K5 and the output end of the sixth switch K6 are both connected to the first end of the first operational amplifier 311 through the fifth resistor R5, and the first end of the first operational amplifier 311 is connected to the output end of the differential amplifier via the sixth resistor R6. In this embodiment, the third switch K3-sixth switch K6 are MOS tubes, triodes or other conventional switches, preferably, the fourth switch K4 and the sixth switch K6 are NMOS tubes, and the third switch K3 and the fifth switch K5 are transmission gates. In other embodiments of the present application, the third switch K3 to the sixth switch K6 may also be NMOS tubes or PMOS tubes, or partly NMOS tubes and partly PMOS tubes, or a combination of NMOS tubes and PMOS tubes.

[0076] In this embodiment, when the second edge trigger 332 receives the reset signal and locks the output high level, and the first edge trigger 331 locks the output low level, the third switch K3 and the sixth switch K6 remain turned on, and the fourth switch K4 and the fifth switch K5 remain turned off. At this time, the addition and subtraction control subunit works in the second state. According to the calculation principle of the operational amplifier, the following formula can be obtained:

[0077] (V1-0)*R5 / (R5+R6)=VADC+(V2-VADC)*R7 / (R7+R8);

[0078] Wherein, V1 is the output voltage of the differential amplifier unit 120, VADC is the compensation value output by the compensation generating unit 320; V2 is the output voltage of the first operational amplifier 311, R5 is the resistance value of the fifth resistor R5, R6 is the resistance value of the sixth resistor R6, R7 is the resistance value of the seventh resistor R7, R8 is the resistance value of the eighth resistor R8, and the resistance value of the fifth resistor R5 is equal to the resistance value of the sixth resistor, the resistance value of the seventh resistor is equal to the resistance value of the eighth resistor R8, and the voltage of the system ground terminal VBAT- is 0. The above formula is simplified to obtain:

[0079] V2 = V1 - VADC;

[0080] When the first edge trigger 331 receives the reset signal and locks the output high level, and the second edge trigger 332 locks the output low level, the fourth switch K4 and the fifth switch K5 remain turned on, and the third switch K3 and the sixth switch K6 remain turned off. At this time, the addition and subtraction control subunit works in the first state. According to the calculation principle of the operational amplifier, the following formula can be obtained:

[0081] VADC+(V1-VADC)*R5 / (R5+R6)=(V2-0)*R7 / (R7+R8);

[0082] After simplification, we get the following formula:

[0083] V2=V1+VADC;

[0084] Therefore, when the third switch K3 and the sixth switch K6 are turned on, a subtraction operation is performed, and when the fourth switch K4 and the fifth switch K5 are turned on, an addition operation is performed, and the compensation value is VADC.

[0085] In this embodiment, the difference control module 400 includes a voltage comparator 410 and an adjustment control unit 420, and the adjustment control unit 420 includes a third edge trigger 421, a fourth edge trigger 422 and a first logic gate unit 440. The first end of the voltage comparator 410 is connected to the first reference voltage Vref, and the first reference voltage Vref is 0. When the resistance bridge 200 is manufactured relatively ideally and the circuit in front of the voltage comparator 410 is also manufactured relatively ideally, its output voltage is the first reference voltage Vref. Of course, the first reference voltage Vref can also be other preset values. The second end of the voltage comparator 410 is connected to the output end of the first operational amplifier 311, and the output end of the voltage comparator 410 is respectively connected to the first end of the third edge trigger 421 and the first end of the fourth edge trigger 422. The second end of the third edge trigger 421 and the fourth edge trigger 422 are connected to the output end of the first operational amplifier 311. The second end is connected to the system power supply end VBAT+, the output end of the third edge trigger 421 is connected to the first logic gate unit 440, the output end of the fourth edge trigger 422 is connected to the first logic gate unit 440, the output end of the first logic gate unit 440 is connected to the counter 322, and the reset end of the third edge trigger 421 and the reset end of the fourth edge trigger 422 are used to receive a reset signal, wherein the triggering mode of the third edge trigger 421 and the fourth edge trigger 422 are opposite, for example, in this embodiment, the third edge trigger 421 is triggered by the rising edge, and the fourth edge trigger 422 is triggered by the falling edge, or vice versa. In this embodiment, the first logic gate unit 440 is, for example, a NOR gate. In addition, in other embodiments of the present application, the first logic gate unit 440 can also be set to other logic units as needed. In this embodiment, the third edge trigger 421 and the fourth edge trigger 422 are D triggers, the first input ends of the third edge trigger 421 and the fourth edge trigger 422 are CP ends, and the second input ends of the third edge trigger 421 and the fourth edge trigger 422 are D ends. In addition, in other embodiments of the present application, the third edge trigger 421 and the fourth edge trigger 422 may also be other edge triggers.In addition, in other embodiments of the present application, only one of the first edge trigger 331 and the second edge trigger 332 may be included. Here, the edge trigger represents one of the first edge trigger 331 and the second edge trigger 332. Here, the first edge trigger 331 is used as an example for explanation. The operation judgment unit includes an edge trigger and a first inverter DV1, wherein the first input end of the edge trigger is used to receive a reset signal, the second input end of the edge trigger is connected to the difference control module 400, the output end of the edge trigger is connected to the addition and subtraction unit, and the output end of the edge trigger is also connected to the addition and subtraction unit via the first inverter. Specifically, the output end of the edge trigger is connected to the control end of the fourth switch and the control end of the fifth switch, and the output of the edge trigger is connected to the control end of the third switch and the control end of the sixth switch via the first inverter, so that the signal received by the control end of the third switch is opposite to the signal received by the control end of the fourth switch. When the edge trigger receives the reset signal, it is triggered, and the edge trigger controls the addition and subtraction unit to perform addition or subtraction according to the signal output by the difference control module.

[0086] Specifically, when the airflow detection circuit is powered on, the counter 322 is reset and cleared, and the compensation value is 0. At the same time, the differential amplifier unit 120, the addition and subtraction unit 310 (for example, the default is addition or subtraction at this time), the voltage comparator 410, the third edge trigger 421, the fourth edge trigger 422, the first logic gate unit 440, etc. are ready. If the output of the voltage comparator 410 is a high level at this time, it means that the voltage at the two input ends of the differential amplifier unit 120 is greater than the first reference voltage Vref after subtraction and amplification (the compensation value is 0). When the reset signal is input, the counter 322 counts from 0 according to the interval timing of the oscillator 321. At this time, the output of the voltage comparator 410 is still at a high level, which means that the difference between the two input terminals of the differential amplifier unit 120 is larger than the first reference voltage Vref after amplification. In order to prevent false triggering, the difference needs to be reduced. At this time, a subtraction operation needs to be performed. Specifically, when the reset signal is output, the second input terminal of the second edge trigger 332 is at a high level, so that the output terminal of the second edge trigger 332 is locked to output a high level. At the same time, the second input terminal of the first edge trigger 331 is at a low level, and the output terminal of the first edge trigger 331 is locked. The output is set to a low level, so that the third switch K3 and the sixth switch K6 remain turned on, and the fourth switch K4 and the fifth switch K5 remain turned off, so that the addition and subtraction unit 310 performs a subtraction operation, so that the voltage at the output end of the adjustment module will be less than the voltage at its input end. Moreover, before and after the reset signal is output, since the voltage comparator 410 always outputs a high level, the outputs of the third edge trigger 421 and the fourth edge trigger 422 are reset to a low level after receiving the reset signal, so that the output of the first logic gate unit 440 is a high level, and the high level is not a counting stop signal. At this time, the counter 322 will not be The control stops counting, and the counter 322 counts from 0 to 1, 2, 3, ... When the counter 322 counts to the critical value -1, the difference between the two input terminals of the differential amplifier unit 120 is still greater than the first reference voltage Vref after amplification and subtraction of the compensation value. The compensation value is (critical value -1)*1mV at this time. At this time, the output of the voltage comparator 410 is still high, and the counter 322 is still counting. When the count value reaches the critical value, the difference between the two input terminals of the differential amplifier unit 120 is smaller than the first reference voltage Vref after amplification and subtraction of the compensation value. The compensation value is (critical value)

[0087] *1mV, at this time, the output of the voltage comparator 410 changes from a high level to a low level. Since the fourth edge trigger 422 is a falling edge trigger in this embodiment, and the second end of the fourth edge trigger 422 is connected to the system power supply terminal VBAT+, the signal output by the fourth edge trigger 422 changes from a low level to a high level, so that the first logic gate unit 440 changes from outputting a high level to outputting a low level. The low level is a count stop signal, and the count stop signal is output to the counter 322. The counter 322 stops counting and retains the count value, and the current count value is retained as a critical value. When the first logic gate unit 440 changes from outputting a high level to outputting a low level, the adjustment module 300 exits the adjustment, and amplifies the difference through the differential amplifier unit 120 and then subtracts the compensation value at this time as the final value. At this time, the difference between the final value and the first reference voltage Vref will be less than a step voltage of the digital-to-analog converter 323. The step voltage is very small, at the mV level, and will not cause misjudgment. In addition, in other embodiments of the present application, the count stop signal can also be set to other levels as needed. In addition, in other embodiments of the present application, the counter 322 may also count discontinuously, such as even counts such as 0, 2, 4, 6, 8, or odd counts, in which case the difference between the final value and the first reference voltage Vref will be smaller than the two step voltages of the digital-to-analog converter 323. In addition, in other embodiments of the present application, the difference between the final value and the first reference voltage Vref may be smaller than a preset number of step voltages of the digital-to-analog converter 323 as required, and the preset number may be set according to actual needs, and the preset number is a positive number greater than or equal to 1, such as 1, 1.5, 2, 2.5, 3, 4, 4.6, 5, 5.5, 6, 6.2, 7, 8, 9, 10, etc.

[0088] In another case, if the output of the voltage comparator 410 is low at this time, it means that the voltage at the two input terminals of the differential amplifier unit 120 is less than the first reference voltage Vref after subtraction operation and amplification (compensation value is 0). When the reset signal is input, the counter 322 counts from 0 according to the interval timing of the oscillator 321. At this time, the output of the voltage comparator 410 is still low, indicating that the difference between the two input terminals of the differential amplifier unit 120 is smaller than the first reference voltage Vref after amplification. In order to prevent false triggering, the difference needs to be increased. At this time, an addition operation needs to be performed, so that the voltage at the output terminal of the adjustment module will be greater than the voltage at its input terminal. Specifically, when the reset signal is output, the second end of the first edge trigger 331 is at a high level, so that the output end of the first edge trigger 331 is locked to output a high level. At the same time, the second input end of the second edge trigger 332 is at a low level, and the output end of the second edge trigger 332 is locked to output a low level, so that the fourth switch K4 and the fifth switch K5 remain turned on and the third switch K3 and the sixth switch K6 remain turned off, so that the addition and subtraction unit 310 performs the addition operation according to the above description. Moreover, after the third edge trigger 421 and the fourth edge trigger 422 receive the reset signal, the outputs of the two are reset to a low level, so that the output of the first logic gate unit 440 is a high level. At this time, the counter 322 will not be controlled to stop counting, and the counter 322 counts from 0 to 1, 2, 3, ... When the counter 322 counts to the critical value -1, the difference between the two input ends of the differential amplifier unit 120 is amplified and subtracted from the complement. After the compensation value is obtained, it is still smaller than the first reference voltage Vref. The compensation value is (critical value-1)*1mV at this time. At this time, the output of the voltage comparator 410 is still at a low level, and the counter 322 is still counting. When the count value reaches the critical value, the difference between the two input terminals of the differential amplifier unit 120 is larger than the first reference voltage Vref after amplification and subtracting the compensation value. The compensation value is (critical value)*1mV at this time. At this time, the output of the voltage comparator 410 changes from a low level to a high level. Since the third edge trigger 421 is a rising edge trigger, and the second end of the third edge trigger 421 is connected to the system power supply terminal VBAT+, the third edge trigger 421 outputs a high level signal, so that the first logic gate unit 440 changes from outputting a high level to outputting a low level. The low level is a counting stop signal. The counting stop signal is output to the counter 322, and the counter 322 stops counting and retains the counting value. The current counting value is retained as the critical value. When the first logic gate unit 440 changes from outputting a high level to outputting a low level, the adjustment module 300 exits the adjustment, and amplifies the difference through the differential amplifier unit 120 and then adds the compensation value at this time as the final value. At this time, the difference between the final value and the first reference voltage Vref is smaller than a step voltage of the digital-to-analog converter 323. The step voltage is very small, at the mV level, and will not cause misjudgment.

[0089] In this embodiment, even if the output voltage of the resistor bridge 200, the differential amplifier unit 120, etc. deviates too much from the first reference voltage Vref due to manufacturing errors when there is no airflow, the deviated voltage is the voltage input to the voltage comparator 410. Since the adjustment module 300 and the difference control module 400 are provided, the adjustment module 300 can adjust the deviated voltage and compare the output voltage adjusted by the adjustment module 300 with the first reference voltage Vref. When the comparison result meets the preset condition, the adjustment module 300 is controlled to stop adjusting. The preset condition is that the difference between the output voltage of the adjustment module 300 and the first reference voltage Vref after adjustment is less than or equal to the difference of a preset number of adjacent compensation values, for example, less than or equal to a preset number of step voltages of the digital-to-analog converter 323. Since the step voltage is preset and controllable, the difference between the output voltage of the adjustment module 300 and the first reference voltage Vref is controlled within the preset number of step voltages, so that the deviation will not be too large, and the airflow threshold voltage will not be reached (see the second embodiment), so that it can be ensured that the airflow detection circuit will not be triggered by mistake after adjustment when there is no airflow, and thus no erroneous operation will occur.

[0090] In addition, in order to facilitate circuit design and voltage comparison, in this embodiment, the airflow detection circuit further includes an amplifying bias unit 510, which is used to amplify the input voltage and provide a second bias voltage, and the second bias voltage is provided to facilitate the comparison of the subsequent voltage comparator 410. In this embodiment, the input end of the amplifying bias unit 510 is connected to the output end of the operator unit, and the output end of the amplifying bias unit 510 is connected to the second end of the voltage comparator 410. Specifically, the amplification bias unit 510 includes a third operational amplifier 511, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12, wherein the first end of the third operational amplifier 511 is connected to the second bias voltage via the ninth resistor R9, and the first end thereof is also connected to the output end of the operational sub-unit via the tenth resistor R10, specifically connected to the output end of the first operational amplifier 311, the second end of the third operational amplifier 511 is connected to the voltage bias via the eleventh resistor R11, and the second end thereof is also connected to the output end of the third operational amplifier 511 via the twelfth resistor R12, and the output end of the third operational amplifier 511 is connected to the second end of the voltage comparator 410. In this embodiment, the resistance of the ninth resistor R9: the resistance of the tenth resistor R10 = the resistance of the twelfth resistor R12: the resistance of the eleventh resistor R11 = the second magnification factor. In this embodiment, the second magnification factor is, for example, 10, 13.5, 20, 30, 40, 40.5, 50, 60, 70.5, 80, etc. It can be set as needed, and the second magnification factor is a positive number greater than 1. Therefore, the voltage at the second end of the voltage comparator 410 is the sum of the voltage after the voltage at the output end of the operator unit is amplified and the second bias voltage. The specific calculation formula is as follows:

[0091] Vp2+(V2-Vp2)*R9 / (R9+R10)=Vp2+(V0'-Vp2)*R11 / (R11+R12);

[0092] Wherein, Vp2 is the second bias voltage, and the second bias voltage is equal to the first bias voltage, and the second bias voltage is preferably equal to the voltage of the first input terminal of the differential amplifier unit 120, V2 is the output voltage of the first operational amplifier 311, V0' is the output voltage of the third operational amplifier 511, R9, R10, R11, and R12 are the resistance values ​​of the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, and the twelfth resistor R12, respectively, and R9:R10=R12:R11, which are all equal to the second amplification factor Y, which are simplified as follows:

[0093] V0'=Vp2+Y*(V2-Vp2);

[0094] The purpose of subtracting the second bias voltage in the brackets in the above formula is to offset the addition of the first bias voltage to the output of the differential amplifier unit 120; if the output of the differential amplifier unit 120 is not superimposed with the first bias voltage, the second bias voltage does not need to be subtracted here (see the following description).

[0095] Since V2 = V1 + VADC, or V2 = V1 - VADC;

[0096] Since V1=Vp1+X*(VA-VB), and Vp2=Vp1, substituting the two equations into the equation of V0', we get:

[0097] V0'=Vp2+Y*[X*(VA-VB)±VADC];

[0098] Moreover, when the input terminal voltage of the second terminal of the voltage comparator 410 is superimposed with a second bias voltage, in order to achieve equal comparison between the two input terminals, the first reference voltage Vref of the first terminal of the voltage comparator 410 also needs to be superimposed with a second bias voltage. In this embodiment, the first reference voltage Vref is the voltage of the system ground terminal VBAT-, that is, 0V, and the airflow detection circuit also includes a reference bias unit 520, and the reference bias unit 520 includes a fourth operational amplifier 521, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, and a sixteenth resistor R16, wherein the first terminal of the fourth operational amplifier 521 is connected to the first reference voltage Vref via the thirteenth resistor R13, and the first terminal thereof is also connected to the second bias voltage via the fourteenth resistor R14, the second terminal of the fourth operational amplifier 521 is connected to the system ground terminal VBAT- via the fifteenth resistor R15, and the second terminal thereof is also connected to the output terminal of the fourth operational amplifier 521 via the sixteenth resistor R16, and the output terminal of the fourth operational amplifier 521 is connected to the first terminal of the voltage comparator 410. In this embodiment, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15 and the sixteenth resistor R16 have the same resistance value, so that the voltage at the first end of the voltage comparator 410 is the sum of the first reference voltage Vref and the second bias voltage. The specific calculation formula is as follows:

[0099] (Vp2-0)*R13 / (R13+R14)=(V0-0)*R15 / (R15+R16);

[0100] Wherein, Vp2 is the second bias voltage, V0 is the output voltage of the fourth operational amplifier 521, R13, R14, R15, and R16 are the resistance values ​​of the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, and the sixteenth resistor R16, respectively, and the resistance values ​​of the thirteenth resistor R13 and the fourteenth resistor R14 are equal, and the resistance values ​​of the fifteenth resistor R15 and the sixteenth resistor R16 are equal, which are simplified as follows:

[0101] V0=0+Vp2;

[0102] In addition, the reference bias unit 520 can also be implemented in other conventional addition circuits. By setting it in this way, the two input terminals of the voltage comparator 410 are superimposed with the second bias voltage, and such processing can facilitate circuit design and voltage comparison. Since the amplification factor of the differential amplifier unit 120 is limited, the purpose of designing the second amplification factor Y here is to further amplify the difference between VA and VB, so as to facilitate the comparison of the voltage comparator 410 later. In this embodiment, the preset condition is that the difference between the voltages at the two input terminals of the difference control module is less than or equal to the product of the second amplification factor Y and the step voltage. At this time, the preset number is the second amplification factor Y, and the voltage output by the addition and subtraction unit after amplification by Y times will be less than or equal to the step voltage by Y times. Since the step voltage and the second amplification factor Y are both controllable, the voltage after adjustment and amplification is ensured not to reach the airflow threshold voltage (see the second embodiment), and will not be triggered by mistake. In addition, in other embodiments of the present application, the preset number may also be twice the second amplification factor Y (when the timer is an odd count or an even count) or three times the second amplification factor Y, etc.

[0103] In addition, in other embodiments of the present application, only an amplification unit or only a bias unit may be provided. Specifically, in one embodiment, only a secondary amplification unit is provided. The difference between this implementation and the present embodiment is that the first end of the third operational amplifier 511 is connected to the system ground terminal VBAT- via the ninth resistor R9, and the second end of the third operational amplifier 511 is connected to the system ground terminal VBAT- via the eleventh resistor R11. At this time, the amplification unit is only used to amplify the input voltage. There is no need to subtract the second bias voltage in the bracket of V0' (at this time, the output voltage of the differential amplifier unit 120 is not superimposed with the first bias voltage), nor is there a need to increase the second bias voltage. Correspondingly, there is no need to design a reference bias unit 520. At this time, the first input end of the voltage comparator 410 is directly connected to the first reference voltage Vref1. In addition, the amplification function can also be realized by other conventional circuits in the art. Here, the secondary amplification unit is located between the adjustment module 300 and the difference control module 400, and such a design is conducive to taking into account both accuracy and reliability. In addition, in another way, when the amplification factor is sufficient, only the second bias unit can be set. The second bias unit is, for example, a conventional adder. One input end of the first adder is connected to the output end of the operator unit, and the other input end thereof is connected to the second bias voltage. The voltage at its output end is the sum of the voltage at the output end of the operator unit and the second bias voltage. The implementation method of the adder can refer to the reference bias unit 520, or it can be other conventional adders in the field. Correspondingly, the airflow detection circuit needs to design a reference bias unit 520.

[0104] In this embodiment, the airflow detection circuit and the resistance bridge 200 constitute an airflow detection component, and the airflow detection component is located in the power supply control component. In addition, in other embodiments of the present application, the airflow detection component can also be located in the heating component. In addition, in other embodiments of the present application, the airflow detection component can also be partially located in the power supply control component and partially located in the heating component.

[0105] In addition, in other embodiments of the present application, the resistance bridge 200 may not be a Wheatstone bridge. The resistance bridge 200 only includes two resistors, which are a third resistor R23 and a fourth resistor R24. The resistance bridge 200 does not include the first voltage output terminal Vout1. In this scheme, one input terminal of the differential amplifier unit 120 is connected to the second voltage output terminal Vout2, and the other input terminal of the differential amplifier unit 120 is connected to a preset second reference voltage. When there is no airflow, the second reference voltage is equal to the voltage of the second voltage output terminal Vout2 (under ideal conditions). When there is a manufacturing error, compensation can also be performed in the above manner. In addition, in other embodiments of the present application, the resistance bridge 200 may also include only one resistor, that is, the third resistor R23. At this time, the first end or the second end of the third resistor R23 is the second voltage output terminal Vout2. At this time, the power supply control component includes a constant current source, which is connected in series with the third resistor R23. Preferably, the constant current source is connected to the system power supply terminal VBAT+. At this time, the second voltage output terminal Vout2 is connected to an input terminal of the differential amplifier unit 120, and the other input terminal of the differential amplifier unit 120 is connected to the second reference voltage. When there is no airflow, the second reference voltage is equal to the voltage of the second voltage output terminal Vout2. When there is a manufacturing error, it can also be compensated according to the above method.

[0106] In this embodiment, the resistance bridge 200 may preferably be formed as a MEMS (Micro-Electro-Mechanical System). In this case, the resistance bridge 200 is formed on the same semiconductor substrate.

[0107] In this embodiment, the airflow detection circuit is made on the same semiconductor substrate, that is, it is located on the same chip, which is called an airflow detection chip. At this time, the system power supply terminal VBAT+ corresponds to the system power supply pin, the system ground terminal VBAT- corresponds to the system ground pin, the voltage input terminal SW corresponds to the voltage input pin, the resistor power supply terminal GD corresponds to the resistor power supply pin, and the atomization terminal AT corresponds to the atomization pin. At this time, the resistor bridge 200 is made on another semiconductor substrate. However, the present application is not limited to this. In other embodiments of the present application, the airflow detection circuit except the power switch M1 is made on the same semiconductor substrate, and the power switch M1 is made on another semiconductor substrate. In addition, in other embodiments of the present application, the airflow detection circuit and some resistors in the resistor bridge 200 (excluding the third resistor R23) are made on the same semiconductor substrate, and the third resistor R23 and the like are made on another semiconductor substrate. In addition, in other embodiments of the present application, the circuit of the airflow detection circuit except the power switch M1 and some resistors in the resistance bridge 200 (excluding the third resistor R23) are made on the same semiconductor substrate, the third resistor R23 and others are made on another semiconductor substrate, and the power switch M1 is made on another semiconductor substrate.

[0108] Second embodiment

[0109] See also Figure 3 , Figure 3 This is a detailed circuit module diagram of the airflow detection circuit of the second embodiment of the present application. This embodiment is similar to the first embodiment, so the parts not described in this embodiment can refer to the first embodiment. The main difference between this embodiment and the first embodiment is that the airflow detection circuit can also monitor the state of the airflow.

[0110] Please refer to Figure 1 and Figure 3In this embodiment, the difference control module 400 can also control whether it is in the adjustment state or the airflow detection state. Specifically, the airflow detection circuit also includes a state selection unit 610, and the state selection unit 610 includes a first switch K1 and a second switch K2. Among them, the first end of the first switch K1 is connected to the airflow threshold voltage Vth, the second end of the first switch K1 is connected to the first end of the thirteenth resistor R13, the first end of the second switch K2 is connected to the first reference voltage Vref, the second end of the second switch K2 is also connected to the first end of the thirteenth resistor R13, the second end of the thirteenth resistor R13 is connected to the first end of the fourth operational amplifier 521, and the control end of the second switch K2 is connected to the output end of the first logic gate unit 440, and the output end of the first logic gate unit 440 is connected to the control end of the first switch K1 via the second inverter DV2. In this embodiment, the first switch K1 and the second switch K2 are MOS tubes, triodes or other conventional switches. Preferably, the first switch K1 is an NMOS tube and the second switch K2 is a transmission gate. In other embodiments of the present application, the first switch K1 and the second switch K2 may also be NMOS tubes or PMOS tubes, or part of them may be NMOS tubes and part of them may be PMOS tubes, or a combination of NMOS tubes and PMOS tubes. In an embodiment, the first reference voltage is less than the airflow threshold voltage Vth. For example, the first reference voltage is 0V, and the airflow threshold voltage Vth is, for example, 0.5V, 0.6V, 0.7V, 0.8V, 0.9V, 1V, etc.

[0111] In this embodiment, when the third edge trigger 421 and the fourth edge trigger 422 receive a reset signal, the third edge trigger 421 and the fourth edge trigger 422 both output a low level, so that the output end of the first logic gate unit 440 outputs a high level, and the high level is a switch-on signal, so that the second switch K2 is turned on, and the output end of the first logic gate unit 440 outputs a low level via the second inverter DV2, and the low level is a switch-off signal, so that the first switch K1 is turned off and cut off, thereby compensating the voltage at the second input end of the voltage comparator 410. The switch-on signal and the switch-off signal can also be set to other level signals as needed. When the voltage at the output end of the voltage comparator 410 changes from a high level to a low level or from a low level to a high level, the corresponding fourth edge trigger 422 outputs a high level or the third edge trigger 421 outputs a high level, so that the output end of the first logic gate unit 440 outputs a low level, the second switch K2 is disconnected and cut off, the voltage compensation ends, and the output end of the first logic gate unit 440 outputs a high level via the second inverter DV2, the first switch K1 is turned on, and then the airflow monitoring is performed, and at the same time, the counter 322 stops counting and retains the current count value. The airflow threshold voltage Vth of this embodiment is used to judge the suction airflow or the blowing airflow, and in this embodiment, it is used to judge the suction airflow.

[0112] In this embodiment, the airflow detection circuit further includes a delay unit 630 and a second logic gate unit 620, wherein the input end of the delay unit 630 is connected to the output end of the voltage comparator 410, the output end of the delay unit 630 is connected to one input end of the second logic gate unit 620, the other input end of the second logic gate unit 620 is connected to the output end of the second inverter DV2, the output end of the second logic gate unit 620 is connected to the logic control unit 130, and the logic control unit 130 is connected to the control end of the power switch M1. In this embodiment, when airflow monitoring is performed, when the voltage at the second end of the voltage comparator 410 is greater than the voltage at the first end and lasts for a preset time designed by the delay unit 630, the delay unit 630 outputs a high level, and the second logic gate unit 620 outputs a suction signal or a blowing signal to the logic control unit 130, which indicates that the resistance bridge 200 is in a suction state or a blowing state. When in the suction state, the logic control unit 130 controls the power switch M1 to be constantly turned on or intermittently turned on, and when in the blowing state, the logic control unit 130 controls the power switch M1 to be turned off. In this embodiment, the second logic gate unit 620 is an AND gate. Of course, in other embodiments of the present application, the second logic gate unit 620 may also be a NAND gate or other logic gates.

[0113] The airflow detection circuit of this embodiment is designed with a state selection unit 610, so that the airflow detection circuit can perform both compensation and airflow monitoring, and most of the circuits can be shared, which is conducive to reducing costs.

[0114] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0115] It should be understood that the "plurality" mentioned in this article refers to two or more. Those skilled in the art will easily think of other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present application are indicated by the following claims.

[0116] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0117] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. An automatic compensation airflow detection circuit, characterized in that: include: A differential amplifier unit, which is used to be connected to the resistance bridge and is used to receive the output voltage of the resistance bridge; A regulating module connected to the output end of the differential amplification unit and used for regulating the voltage at the output end of the differential amplification unit when there is no airflow; The difference control module has one input end connected to the output end of the regulating module and another input end connected to the first reference voltage. The difference control module is used to compare the voltages of the two input ends. When the comparison result meets the preset conditions, the difference control module controls the regulating module to stop regulating.

2. The airflow detection circuit according to claim 1, characterized in that: The regulating module includes an addition and subtraction unit, a compensation generating unit and an operation judgment unit, wherein the addition and subtraction unit is respectively connected to the differential amplification unit, the operation judgment unit and the compensation generating unit, the operation judgment unit and the compensation generating unit are both connected to the difference control module, the operation judgment unit controls the addition and subtraction unit to perform addition or subtraction according to the signal of the difference control module, the compensation generating unit is used to generate a compensation value, and the addition and subtraction unit receives the signal of the operation judgment unit to perform addition or subtraction operation on the voltage at the output end of the differential amplification unit and the compensation value.

3. The airflow detection circuit according to claim 2, characterized in that: After the airflow detection circuit is powered on, the calculation judgment unit controls the addition and subtraction unit to perform addition or subtraction and maintain it according to the signal of the difference control module.

4. The airflow detection circuit according to claim 3, characterized in that: The operation judgment unit includes a first edge trigger and a second edge trigger, wherein the first input end of the first edge trigger and the first input end of the second edge trigger are used to receive a reset signal, the second input end of the first edge trigger and the second input end of the second edge trigger are both connected to the difference control module, and the signal received by the second input end of the first edge trigger is opposite to the signal received by the second input end of the second edge trigger, the output end of the first edge trigger is connected to the addition and subtraction unit, and the output end of the second edge trigger is connected to the addition and subtraction unit, and the first edge trigger and the second edge trigger are triggered when they receive a reset signal, and the first edge trigger and the second edge trigger control the addition and subtraction unit to perform addition or subtraction according to the signal output by the difference control module; or, The operation judgment unit includes an edge trigger and a first inverter, wherein the first input end of the edge trigger is used to receive a reset signal, the second input end of the edge trigger is connected to the difference control module, the output end of the edge trigger is connected to the addition and subtraction unit, and the output end of the edge trigger is also connected to the addition and subtraction unit via the first inverter. When the edge trigger receives the reset signal, it is triggered, and the edge trigger controls the addition and subtraction unit to perform addition or subtraction operations according to the signal output by the difference control module.

5. The airflow detection circuit according to claim 2, characterized in that: The addition and subtraction unit includes an addition and subtraction control subunit and an operator unit, wherein the control end of the addition and subtraction control subunit is connected to the operation judgment unit, the input end of the addition and subtraction control subunit is respectively connected to the compensation generating unit and the system grounding end, the output end of the addition and subtraction control subunit is connected to the operator unit, and the operator unit is also connected to the output end of the differential amplifier unit. When the operation judgment unit controls the addition and subtraction control subunit to work in a first state, the operator unit adds the voltage at the output end of the differential amplifier unit to the compensation value output by the compensation generating unit, and when the operation judgment unit controls the addition and subtraction control subunit to work in a second state, the operator unit subtracts the voltage at the output end of the differential amplifier unit from the compensation value output by the compensation generating unit.

6. The airflow detection circuit according to claim 5, characterized in that: The addition and subtraction control subunit includes a fourth switch, a fifth switch, a third switch and a sixth switch, and the operation subunit includes a first operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor, wherein the control end of the fourth switch and the control end of the fifth switch are connected to the operation judgment unit and receive the same signal, the control end of the third switch and the control end of the sixth switch are connected to the operation judgment unit and receive the same signal, the input end of the fourth switch and the input end of the sixth switch are both connected to the system ground end, the output end of the fourth switch is connected to the second end of the first operational amplifier via the seventh resistor, and the output end of the sixth switch is connected to the first operational amplifier via the fifth resistor. The first end of the differential amplifier is connected to the first end of the differential amplifier, the input end of the fifth switch and the input end of the third switch are both connected to the compensation generating unit to receive the compensation value, the output end of the fifth switch is connected to the first end of the first operational amplifier via the fifth resistor, the output end of the third switch is connected to the second end of the first operational amplifier via the seventh resistor, the first end of the first operational amplifier is connected to the output end of the differential amplifier unit via the sixth resistor, the second end of the first operational amplifier is connected to the output end of the first operational amplifier via the eighth resistor, and when the fourth switch and the fifth switch are turned on, the third switch and the sixth switch are turned off; when the third switch and the sixth switch are turned on, the fourth switch and the fifth switch are turned off.

7. The airflow detection circuit according to claim 2, characterized in that: The compensation generating unit comprises a counting subunit and a digital-to-analog converter, wherein the counting subunit is connected to the difference control module, and the counting subunit is also used to receive a reset signal. When the counting subunit receives the reset signal, it starts counting, and when the counting subunit receives a stop counting signal output by the difference control module, it stops counting. The digital-to-analog converter is connected to the counting subunit, and the digital-to-analog converter is used to convert the current count value of the counting subunit into a voltage value, and the voltage value is used to output to the addition and subtraction unit.

8. The airflow detection circuit according to claim 7, characterized in that: The counting subunit includes an oscillator and a counter, and the compensation generating unit also includes a voltage follower, wherein the counter is respectively connected to the oscillator and the difference control module, and the counter is also used to receive a reset signal, the counter is connected to the digital-to-analog converter, and the output end of the digital-to-analog converter is connected to the voltage follower, and the voltage follower outputs the compensation value to the addition and subtraction unit.

9. The airflow detection circuit according to claim 7, characterized in that: The preset condition is that the difference between the voltages at the two input terminals of the difference control module is less than or equal to a preset number of step voltages, wherein the step voltage is the voltage accuracy of the digital-to-analog converter, and the preset number is a positive number greater than or equal to 1.

10. The airflow detection circuit according to claim 1, characterized in that: The difference control module includes a voltage comparator and an adjustment control unit, wherein the first end of the voltage comparator is connected to the first reference voltage, the second end of the voltage comparator is connected to the output end of the adjustment module, the output end of the voltage comparator is connected to the adjustment module, the output end of the voltage comparator is also connected to the adjustment control unit, and the output end of the adjustment control module is connected to the adjustment module; Wherein, when the voltage at the second end of the voltage comparator is greater than the voltage at its first end, the difference control module controls the adjustment module so that the voltage at the output end of the adjustment module is less than the voltage at its input end; when the voltage at the second end of the voltage comparator is less than the voltage at its first end, the difference control module controls the adjustment module so that the voltage at the output end of the adjustment module is greater than the voltage at its input end; when the output level of the voltage comparator changes, the adjustment control module controls the adjustment module to stop adjustment.

11. The airflow detection circuit according to claim 10, characterized in that: The regulation control unit includes a third edge trigger, a fourth edge trigger and a first logic gate unit, wherein the first end of the third edge trigger and the first end of the fourth edge trigger are both connected to the output end of the voltage comparator, the second end of the third edge trigger and the second end of the fourth edge trigger are both connected to the system power supply end, the output end of the third edge trigger and the output end of the fourth edge trigger are respectively connected to the first logic gate unit, and one of the third edge trigger and the fourth edge trigger is a rising edge trigger, and the other is a falling edge trigger, the output end of the first logic gate unit is connected to the regulation module, and the third edge trigger and the fourth edge trigger are also used to receive a reset signal.

12. The airflow detection circuit according to any one of claims 1 to 11, characterized in that: The airflow detection circuit further includes an amplifying bias unit and a reference bias unit, wherein the amplifying bias unit is connected to the regulating module and the difference control module respectively, the amplifying bias unit is used to amplify the voltage output by the regulating module and output it to the input end of the difference control module after superimposing the second bias voltage, the reference bias unit is connected to the difference control module, and the reference bias unit is used to output the first reference voltage to the input end of the difference control module after superimposing the second bias voltage; or, The airflow detection circuit also includes a second bias unit and a reference bias unit, wherein the second bias unit is connected to the adjustment module and the difference control module respectively, and the second bias unit is used to superimpose the voltage output by the adjustment module with the second bias voltage and output it to the input end of the difference control module, and the reference bias unit is connected to the difference control module, and the reference bias unit is used to superimpose the first reference voltage with the second bias voltage and output it to the input end of the difference control module.

13. The airflow detection circuit according to any one of claims 1 to 11, characterized in that: The differential amplifier unit is used to subtract the voltages at its two input terminals, amplify them, add a first bias voltage, and then output them to the adjustment module. The airflow detection circuit is also designed to subtract the first bias voltage from the voltage at the output terminal of the adjustment module and then output it to the input terminal of the difference control module.

14. The airflow detection circuit according to any one of claims 1 to 11, characterized in that: The airflow detection circuit also includes a state selection unit, the input of the state selection unit is respectively connected to a first reference voltage and an airflow threshold voltage, the output end of the state selection unit is connected to the input end of the difference control module, the state selection unit is used to select the first reference voltage or the airflow threshold voltage output, when the airflow detection circuit is powered on, the state selection unit selects the first reference voltage output, when the comparison result meets the preset conditions, the state selection unit selects the airflow threshold voltage output to monitor the airflow, wherein the first reference voltage is less than the airflow threshold voltage.

15. The airflow detection circuit according to claim 14, characterized in that: The airflow detection circuit further includes a second inverter, a second logic gate unit, a delay unit and a logic control unit, wherein the input end of the second inverter is connected to the output end of the difference control module, the output end of the second inverter is connected to an input end of the second logic gate unit, the difference control module is connected to the other input end of the second logic gate unit via the delay unit, and the output end of the logic gate unit is connected to the logic control unit; The state selection unit includes a first switch and a second switch, wherein the control end of the first switch is connected to the output end of the second inverter, the input end of the first switch is connected to the airflow threshold voltage, the output end of the first switch is connected to the input end of the difference control module, the control end of the second switch is connected to the output end of the difference control module, the input end of the second switch is connected to the first reference voltage, and the output end of the second switch is connected to the input end of the difference control module.

16. An airflow detection assembly, characterized in that: include: a resistance bridge configured such that the flow of airflow causes a change in resistance, and when the resistance bridge is powered, the resistance bridge is configured to cause a change in output voltage based on the change in resistance; The airflow detection circuit according to any one of claims 1 to 15, wherein the airflow detection circuit is connected to the resistance bridge.

17. An electronic device, characterized in that: include: power supply; The airflow detection component according to claim 16 or the airflow detection circuit according to any one of claims 1-15, wherein the airflow detection circuit is connected to the power supply.

18. An automatic compensation airflow detection chip, used to connect to a resistance bridge, characterized in that: include: A differential amplifier unit, which is used to be connected to the resistance bridge and is used to receive the output voltage of the resistance bridge; A regulating module connected to the output end of the differential amplification unit and used for regulating the voltage at the output end of the differential amplification unit when there is no airflow; The difference control module has one input end connected to the output end of the regulating module and another input end connected to the first reference voltage. The difference control module is used to compare the voltages of the two input ends. When the comparison result meets the preset conditions, the difference control module controls the regulating module to stop regulating.

Images