Resistance measuring circuit and electronic atomization device

Abstract

The invention relates to the technical field of electronic atomization, in particular to a resistance measuring circuit and an electronic atomization device. According to the invention, the switch unit is switched on after receiving the control signal, and the resistance measuring circuit measures the resistance of the heating body. Specifically, the controller obtains a first voltage of the first voltage measuring point and a second voltage of the second voltage measuring point, calculates a voltage difference between the first voltage and the second voltage, calculates a current of the current measuring resistor according to the voltage difference and a resistance value of the current measuring resistor, and then calculates a resistance value of the heating body according to the second voltage and the current of the current measuring resistor. By adopting the implementation scheme, the resistance value of the heating body can be accurately obtained, whether the current resistance value of the heating body is normal, too large or too small can be judged in real time according to the resistance value of the heating body, and a response is quickly made.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic atomization, and in particular to a resistance measuring circuit and an electronic atomization device. Background Art

[0002] Electronic atomization devices such as electronic cigarettes include a host and a cartridge. Since the heating wires of existing cartridges have different resistance values, in order to facilitate the host to identify the resistance value of the heating wire in the cartridge and automatically adjust the heating power, a resistance measuring circuit for measuring the resistance of the heating wire is generally provided. However, the current resistance measuring circuit can only realize the resistance measuring function, and the current resistance measuring circuit generally has a PN junction connected in series in the circuit, resulting in a deviation in the measured voltage drop, making the measured resistance too large and requiring correction. Summary of the invention

[0003] The present invention provides a resistance measuring circuit and an electronic atomization device, which effectively solve the problems of low resistance measuring accuracy and single function of the existing electronic atomization device.

[0004] According to the first aspect, an embodiment provides a resistance measuring circuit, comprising:

[0005] A switch unit, the switch unit comprising an input end, an output end and a control end, the input end of the switch unit is used to connect to a power source, and the control end of the switch unit is used to receive a control signal; the control signal is used to control the on or off of the switch unit;

[0006] A current measuring resistor, wherein a first end of the current measuring resistor is used to connect to an output end of the switch unit, and a second end of the current measuring resistor is used to connect to one end of a heating element;

[0007] A first voltage measurement point is provided at the first end of the current measuring resistor, and a second voltage measurement point is provided at the second end of the current measuring resistor; the first voltage measurement point and the second voltage measurement point are respectively connected to a controller;

[0008] The other end of the heating element is grounded.

[0009] In an achievable implementation, the control end of the switch unit is connected to the controller, and the controller is used to:

[0010] Sending a control signal to the control terminal of the switch unit to turn on the switch unit;

[0011] Obtaining a first voltage at a first end of the current measuring resistor and a second voltage at a second end of the current measuring resistor;

[0012] Calculating the current of the current measuring resistor according to the voltage difference between the first voltage and the second voltage and the resistance value of the current measuring resistor;

[0013] The resistance of the heating element is calculated according to the second voltage and the current of the current measuring resistor.

[0014] In an achievable implementation, an output circuit is further provided at one end of the heating element, the output circuit includes a control end, and the control end of the output circuit is connected to the controller; the controller is also used for:

[0015] Determine whether the level of the second voltage measurement point is a high level; if so, the resistance measurement circuit works normally; otherwise, control the output circuit to be closed.

[0016] In an achievable implementation, the switch unit includes a transistor, a first resistor, and a second resistor; the emitter of the transistor is connected to the power supply, and the collector of the transistor is connected to the first end of the current measuring resistor; the first end of the first resistor is connected to the emitter of the transistor, and the second end of the first resistor is connected to the pin of the single-chip computer; the first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the base of the transistor;

[0017] or,

[0018] The switch unit includes a MOS tube, a first resistor and a second resistor; the source of the MOS tube is connected to the power supply, and the drain of the MOS tube is connected to the first end of the current measuring resistor; the first end of the first resistor is connected to the source of the MOS tube, and the second end of the first resistor is connected to the pin of the single-chip computer; the first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the gate of the MOS tube.

[0019] In an achievable implementation, a fourth resistor is provided on the line connecting the first voltage measurement point to the controller; and a fifth resistor is provided on the line connecting the second voltage measurement point to the controller.

[0020] In an achievable implementation, it further includes a voltage divider circuit, wherein an input end of the voltage divider circuit is connected to an input end of the switch unit, and an output end of the voltage divider circuit is connected to a second end of the current measuring resistor;

[0021] The controller is also used for:

[0022] Determine whether the level of the second voltage measurement point is a low level; if so, the resistance measurement circuit works normally; otherwise, set a falling edge to make the level of the second voltage measurement point a low level.

[0023] In an achievable implementation, the voltage divider circuit comprises a third resistor, a first end of the third resistor is connected to the input end of the switch unit, and a second end of the third resistor is connected to the second end of the current measuring resistor.

[0024] According to the second aspect, an embodiment provides a resistance measuring circuit, comprising:

[0025] A switch unit, the switch unit comprising an input end, an output end and a control end, the input end of the switch unit is used to connect to a power source, and the control end of the switch unit is used to receive a control signal; the control signal is used to control the on or off of the switch unit;

[0026] A current measuring resistor, wherein a first end of the current measuring resistor is used to connect to an output end of the switch unit, and a second end of the current measuring resistor is used to connect to one end of a heating element;

[0027] A voltage-dividing resistor, wherein a first end of the voltage-dividing resistor is used to connect to an input end of the switch unit, and a second end of the voltage-dividing resistor is used to connect to a second end of the current measuring resistor;

[0028] A voltage measurement point is provided at the second end of the current measuring resistor; the voltage measurement point is connected to a controller;

[0029] The other end of the heating element is grounded.

[0030] In one possible implementation, the controller is used to:

[0031] Sending a control signal to the control terminal of the switch unit to turn on the switch unit;

[0032] Obtaining a power supply voltage and a second voltage at a second end of the current measuring resistor;

[0033] calculating the current of the current measuring resistor according to the voltage difference between the power supply voltage and the second voltage, the resistance value of the current measuring resistor and the resistance value of the switch unit;

[0034] The resistance of the heating element is calculated according to the second voltage and the current of the current measuring resistor.

[0035] According to the third aspect, an electronic atomization device is provided in one embodiment, comprising the resistance measuring circuit as described above.

[0036] According to a resistance measuring circuit / electronic atomization device of the above embodiment, the switch unit is turned on after receiving the control signal, and the resistance measuring circuit measures the resistance of the heating element. Specifically, the controller obtains the first voltage at the first voltage measurement point and the second voltage at the second voltage measurement point, and calculates the voltage difference between the first voltage and the second voltage, calculates the current of the current measuring resistor according to the pressure difference and the resistance value of the current measuring resistor, and then calculates the resistance value of the heating element according to the second voltage and the current of the current measuring resistor. By adopting this embodiment, not only can the resistance value of the heating element be accurately obtained, but also the current resistance value of the heating element can be judged in real time through the resistance value of the heating element whether it is normal, too large or too small, and a quick response can be made. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The structure of a resistance measuring circuit provided in this embodiment is Figure 1 ;

[0038] Figure 2 The structure of a resistance measuring circuit provided in this embodiment is Figure 2 ;

[0039] Figure 3 The structure of a resistance measuring circuit provided in this embodiment is Figure 3 ;

[0040] Figure 4 The structure of a resistance measuring circuit provided in this embodiment is Figure 4 .

[0041] Figure numerals: 10, switch unit; 20, heating element; 30, voltage divider circuit. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0043] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0044] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0045] like Figure 1 As shown, a resistance measuring circuit provided in this embodiment includes a switch unit 10, a current measuring resistor R6 and a heating element 20. Among them, the switch unit 10 includes an input end, an output end and a control end, the input end of the switch unit 10 is used to connect to a power supply, and the control end of the switch unit 10 is used to receive a control signal; the control signal is used to control the on or off of the switch unit 10; the first end of the current measuring resistor R6 is used to connect to the output end of the switch unit 10, and the second end of the current measuring resistor R6 is used to connect to one end of the heating element 20; the first end of the current measuring resistor R6 is provided with a first voltage measuring point A, and the second end of the current measuring resistor R6 is provided with a second voltage measuring point B; the first voltage measuring point A and the second voltage measuring point B are respectively connected to the controller; the other end of the heating element 20 is grounded.

[0046] The control end of the switch unit 10 is connected to the controller. When the switch unit 10 is turned on, the specific control process is as follows:

[0047] A control signal is sent to the control end of the switch unit 10 to turn on the switch unit 10; a first voltage at the first end of the current measuring resistor R6 and a second voltage at the second end of the current measuring resistor R6 are obtained; the current of the current measuring resistor R6 is calculated based on the voltage difference between the first voltage and the second voltage and the resistance value of the current measuring resistor R6; the resistance value of the heating element 20 is calculated based on the second voltage and the current of the current measuring resistor R6.

[0048] In this embodiment, combined with Figure 1 As shown, as an implementation method, the controller can be a single-chip microcomputer, and the control end of the switch unit 10 is connected to the RL_DET_EN pin of the single-chip microcomputer. The single-chip microcomputer turns on the switch unit 10 by changing the level of the RL_DET_EN pin from high to low. In addition, the first voltage measurement point A and the second voltage measurement point B are also connected to two pins of the single-chip microcomputer respectively. Figure 1 , the ADC_RR pin is connected to the first voltage measurement point A, and the ADC_RL pin is connected to the second voltage measurement point B.

[0049] In actual use, after the switch unit 10 is turned on, the power supply supplies power to the resistance measuring circuit, and the current measuring resistor R6 is used as a current sampling resistor (generally a standard resistor with a known resistance value). The voltages at the first end and the second end of the current measuring resistor R6 are obtained through the first voltage measurement point A and the second voltage measurement point B, respectively. The voltage difference between the voltage at the first end of the current measuring resistor R6 (i.e., the first voltage) and the voltage at the second end (i.e., the second voltage) is the voltage of the current measuring resistor R6. The current I6 flowing through the current measuring resistor R6 can be calculated according to Ohm's law, and the specific calculation formula is: Since the current measuring resistor R6 and the heating element 20 are connected in series in the resistance measuring circuit of the present embodiment, the current of the current measuring resistor R6 and the current of the heating element 20 are the same. At this time, since the other end of the heating element 20 is grounded, the voltage of the second end of the current measuring resistor R6 can be used as the voltage of the heating element 20. The voltage of the heating element 20 and the current flowing through the heating element 20 are known, and the resistance value R of the heating element 20 is calculated. The specific calculation formula is: R = V ADC _ RL / I6.

[0050] By adopting the above-mentioned scheme of this embodiment, not only can the resistance value of the heating element 20 be accurately obtained, but also the current resistance value of the heating element 20 can be judged in real time through the resistance value of the heating element 20 as normal, too large or too small, and corresponding prompts can be made quickly. Compared with the existing judgment process, the scheme of the present application greatly improves the judgment time, and this process only takes about 10μm.

[0051] In some embodiments, an output circuit is further provided at one end of the heating element 20, and the output circuit includes a control end, and the control end of the output circuit is connected to a controller; the controller is also used for:

[0052] It is determined whether the level of the second voltage measurement point B is a high level; if so, the resistance measurement circuit works normally; otherwise, the output circuit is controlled to be closed.

[0053] In practical applications, the output circuit can be a heating circuit, which controls whether to heat the heating element 20 through a controller. Specifically, the state of the heating element 20 is determined by judging the level of the ADC_RL pin of the single-chip microcomputer. When the ADC_RL pin is at a high level, it means that the resistance measuring circuit works normally, and the resistance measuring work can be performed normally on the heating element 20. At this time, the output circuit has current input. When the ADC_RL pin is at a low level, it means that the heating element 20 is short-circuited. At this time, the controller will control the output circuit to close in time to prevent damage to other components. Therefore, the present embodiment can quickly determine whether the heating element 20 is short-circuited by judging whether the level of the second voltage measurement point B is high, and can respond to the short circuit and make corresponding responses in time. Compared with the prior art, the resistance value of the heating element 20 is read by the ADC function of the single-chip microcomputer to determine whether the heating element 20 is short-circuited, which will waste the response time of the single-chip microcomputer, resulting in failure to stop the output circuit current in time and damage other components.

[0054] Furthermore, as an implementation solution, refer to Figure 1 and Figure 2 The switch unit 10 includes a transistor Q1, a first resistor R1 and a second resistor R2; the emitter of the transistor Q1 is connected to a power supply, and the collector of the transistor Q1 is connected to a first end of a current measuring resistor R6; the first end of the first resistor R1 is connected to the emitter of the transistor Q1, and the second end of the first resistor R1 is connected to a pin of the microcontroller; the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is connected to the base of the transistor Q1.

[0055] The transistor Q1 in this embodiment is a current control device, which works in the cut-off region and the saturation region. When the base current of the transistor Q1 is zero or very small (i.e., the RL_DET_EN pin is at a high level), the transistor Q1 is in the cut-off state, at which time the collector and the emitter are equivalent to a high impedance state, and the circuit is disconnected; when the base current increases to a certain extent (i.e., the RL_DET_EN pin changes from a high level to a low level), the transistor Q1 enters the saturation region, at which time the collector current increases with the change of the base current, but the voltage drop between the collector and the emitter is very small, and the circuit is equivalent to the on state. At the same time, when the transistor Q1 is turned on, the pin will be damaged due to the increase in the current between the power supply and the RL_DET_EN pin of the single-chip computer. Therefore, the first resistor R1 is set to limit the current to protect the RL_DET_EN pin from damage. Similarly, a second resistor R2 is set on the line connecting the power supply and the base to achieve current limiting to extend the service life of the transistor Q1.

[0056] As another implementation, refer to Figure 3The switch unit 10 includes a MOS tube Q2, a first resistor R1 and a second resistor R2; the source of the MOS tube Q2 is connected to the power supply, and the drain of the MOS tube Q2 is connected to the first end of the current measuring resistor R6; the first end of the first resistor R1 is connected to the source of the MOS tube Q2, and the second end of the first resistor R1 is connected to the pin of the single chip computer; the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is connected to the gate of the MOS tube Q2.

[0057] The MOS tube Q2 (metal oxide semiconductor field effect transistor) in this embodiment is a voltage control device, which realizes the switching function by controlling the channel current through the gate voltage. When the RL_DET_EN pin of the single-chip computer changes from a high level to a low level (that is, the gate voltage of the MOS tube Q2 reaches a certain threshold), a conductive channel is formed, and the source and drain of the MOS tube Q2 are connected; when the RL_DET_EN pin is a high level (that is, the gate voltage of the MOS tube Q2 is lower than the threshold), the channel is closed, and the source and drain of the MOS tube Q2 are cut off. Similarly, when the MOS tube Q2 is turned on, the pin will be damaged due to the increase of the current between the power supply and the RL_DET_EN pin of the single-chip computer. Therefore, the first resistor R1 is set to limit the current to protect the RL_DET_EN pin from damage. The second resistor R2 is set on the line connecting the power supply and the gate to achieve the current limiting effect, so as to extend the service life of the MOS tube Q2.

[0058] In some embodiments, a fourth resistor R4 is provided on the line connecting the first voltage measurement point A to the controller; and a fifth resistor R5 is provided on the line connecting the second voltage measurement point B to the controller.

[0059] In the present embodiment, when the single-chip microcomputer pin is connected to a circuit with a large load (such as a heating element 20), if the connection is suddenly disconnected, the load will generate a reverse electromotive force, which may cause damage to the single-chip microcomputer pin. After setting the resistor on the line, the rate of change of the current can be limited, thereby reducing the amplitude of the reverse electromotive force and protecting the safety of the single-chip microcomputer pin. Therefore, in the present embodiment, a fourth resistor R4 is provided on the line connecting the controller at the first voltage measurement point A, and a fifth resistor R5 is provided on the line connecting the controller at the second voltage measurement point B, so as to protect the ADC_RR pin and the ADC_RL pin. At the same time, when the signal of the ADC_RR pin of the single-chip microcomputer passes through the fourth resistor R4 and the signal of the ADC_RL pin passes through the fifth resistor R5, the fourth resistor R4 and the fifth resistor R5 will respectively consume a part of the electric energy and convert it into heat energy, thereby reducing the amplitude of the signal, and then can play a certain filtering role.

[0060] In some embodiments, reference Figure 2 and Figure 3, the resistance measuring circuit further includes a voltage divider circuit 30, the input end of the voltage divider circuit 30 is connected to the input end of the switch unit 10, and the output end of the voltage divider circuit 30 is connected to the second end of the current measuring resistor R6;

[0061] The controller is also used to:

[0062] Determine whether the level of the second voltage measurement point B is a low level; if so, the resistance measurement circuit works normally; otherwise, set a falling edge to make the level of the second voltage measurement point B a low level.

[0063] Specifically, the voltage divider circuit 30 of this embodiment includes a third resistor R3 , a first end of the third resistor R3 is connected to the input end of the switch unit 10 , and a second end of the third resistor R3 is connected to the second end of the current measuring resistor R6 .

[0064] In actual application, the resistance of the third resistor R3 is generally at the level of 100KΩ, and the heating element 20 is generally less than 3Ω. Therefore, when the resistance measuring circuit works normally (i.e., the heating element 20 is normally connected), the third resistor R3 and the heating element 20 divide the voltage, and the level of the ADC_RL pin is in a low level state. When the heating element 20 is not connected, the pull-up ADC_RL pin of the third resistor R3 is at a high level, which triggers the falling edge wake-up instruction of the single-chip microcomputer, and sets the falling edge to reduce the second voltage measurement point B from a high level to a low level. Therefore, in this embodiment, by adding a voltage divider circuit 30, and by measuring the level of the pull-up ADC_RL pin of the third resistor R3, it is identified whether the heating element 20 in the resistance measuring circuit is correctly connected.

[0065] refer to Figure 4 , a resistance measuring circuit provided in this embodiment includes a switch unit 10, a current measuring resistor R6, a voltage dividing resistor and a heating element 20. Among them, the switch unit 10 includes an input end, an output end and a control end, the input end of the switch unit 10 is used to connect to the power supply, and the control end of the switch unit 10 is used to receive a control signal; the control signal is used to control the on or off of the switch unit 10; the first end of the current measuring resistor R6 is used to connect to the output end of the switch unit 10, and the second end of the current measuring resistor R6 is used to connect to one end of the heating element 20; the first end of the voltage dividing resistor is used to connect to the input end of the switch unit 10, and the second end of the voltage dividing resistor is used to connect to the second end of the current measuring resistor R6; the second end of the current measuring resistor R6 is provided with a voltage measuring point C; the voltage measuring point C is connected to the controller; the other end of the heating element 20 is grounded.

[0066] The control end of the switch unit 10 is connected to the controller. When the switch unit 10 is turned on, the specific control process is as follows:

[0067] A control signal is sent to the control end of the switch unit 10 to turn on the switch unit 10; the power supply voltage and the second voltage at the second end of the current measuring resistor R6 are obtained; the current of the current measuring resistor R6 is calculated based on the voltage difference between the power supply voltage and the second voltage, the resistance value of the current measuring resistor R6 and the resistance value of the switch unit 10; the resistance value of the heating element 20 is calculated based on the second voltage and the current of the current measuring resistor R6.

[0068] In the case where the I / O port (i.e., input port or output port) in the single-chip microcomputer is insufficient, the resistance measuring circuit of this embodiment can be used to measure the resistance of the heating element 20. Specifically, the voltage of the voltage measuring point C is obtained through the ADC_RL pin of the single-chip microcomputer, and then the voltage difference between the power supply voltage and the voltage of the voltage measuring point C is calculated. The voltage difference is the voltage between the current measuring resistor R6 and the switch unit 10. When the resistance value of the current measuring resistor R6 and the switch unit 10 and the voltage of the current measuring resistor R6 and the switch unit 10 are known, the current flowing through the current measuring resistor R6 and the switch unit 10 can be obtained. Since the current measuring resistor R6, the switch unit 10 and the heating element 20 are in series, the current of the heating element 20 is the same as the current of the current measuring resistor R6. At this time, since the other end of the heating element 20 is grounded, the voltage of the second end of the current measuring resistor R6 can be used as the voltage of the heating element 20. The voltage of the heating element 20 and the current flowing through the heating element 20 are known, and the resistance of the heating element 20 is calculated.

[0069] In addition, the resistance measuring circuit of this embodiment can also identify whether the heating element 20 in the resistance measuring circuit is correctly connected. The identification principle is the same as the identification principle of the resistance measuring circuit when the voltage divider circuit 30 is included. This embodiment will not be described in detail here.

[0070] This embodiment provides an electronic atomization device, including the resistance measuring circuit as described above. Since the resistance measuring circuit has been described in detail in the above embodiment, this embodiment will not be described in detail here.

[0071] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A resistance measuring circuit, characterized in that: include: A switch unit, the switch unit comprising an input end, an output end and a control end, the input end of the switch unit is used to connect to a power source, and the control end of the switch unit is used to receive a control signal; The control signal is used to control the on or off of the switch unit; A current measuring resistor, wherein a first end of the current measuring resistor is used to connect to an output end of the switch unit, and a second end of the current measuring resistor is used to connect to one end of a heating element; A first voltage measurement point is provided at the first end of the current measuring resistor, and a second voltage measurement point is provided at the second end of the current measuring resistor; the first voltage measurement point and the second voltage measurement point are respectively connected to a controller; The other end of the heating element is grounded.

2. The resistance measuring circuit according to claim 1, characterized in that: The control end of the switch unit is connected to the controller, and the controller is used to: Sending a control signal to the control terminal of the switch unit to turn on the switch unit; Obtaining a first voltage at a first end of the current measuring resistor and a second voltage at a second end of the current measuring resistor; Calculating the current of the current measuring resistor according to the voltage difference between the first voltage and the second voltage and the resistance value of the current measuring resistor; The resistance of the heating element is calculated according to the second voltage and the current of the current measuring resistor.

3. The resistance measuring circuit according to claim 1, characterized in that: An output circuit is also provided at one end of the heating element, and the output circuit includes a control end, and the control end of the output circuit is connected to the controller; the controller is also used for: Determine whether the level of the second voltage measurement point is a high level; if so, the resistance measurement circuit works normally; otherwise, control the output circuit to be closed.

4. The resistance measuring circuit according to claim 1, characterized in that: The switch unit includes a transistor, a first resistor and a second resistor; the emitter of the transistor is connected to the power supply, and the collector of the transistor is connected to the first end of the current measuring resistor; the first end of the first resistor is connected to the emitter of the transistor, and the second end of the first resistor is connected to the pin of the single-chip computer; the first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the base of the transistor; or, The switch unit includes a MOS tube, a first resistor and a second resistor; the source of the MOS tube is connected to the power supply, and the drain of the MOS tube is connected to the first end of the current measuring resistor; the first end of the first resistor is connected to the source of the MOS tube, and the second end of the first resistor is connected to the pin of the single-chip computer; the first end of the second resistor is connected to the second end of the first resistor, and the second end of the second resistor is connected to the gate of the MOS tube.

5. The resistance measuring circuit according to claim 1, characterized in that: A fourth resistor is provided on the line connecting the first voltage measurement point to the controller; a fifth resistor is provided on the line connecting the second voltage measurement point to the controller.

6. The resistance measuring circuit according to claim 1, characterized in that: It also includes a voltage divider circuit, wherein the input end of the voltage divider circuit is connected to the input end of the switch unit, and the output end of the voltage divider circuit is connected to the second end of the current measuring resistor; The controller is also used for: Determine whether the level of the second voltage measurement point is a low level; if so, the resistance measurement circuit works normally; otherwise, set a falling edge to make the level of the second voltage measurement point a low level.

7. The resistance measuring circuit according to claim 6, characterized in that: The voltage divider circuit includes a third resistor, a first end of the third resistor is connected to the input end of the switch unit, and a second end of the third resistor is connected to the second end of the current measuring resistor.

8. A resistance measuring circuit, characterized in that: include: A switch unit, the switch unit comprising an input end, an output end and a control end, the input end of the switch unit is used to connect to a power source, and the control end of the switch unit is used to receive a control signal; The control signal is used to control the on or off of the switch unit; A current measuring resistor, wherein a first end of the current measuring resistor is used to connect to an output end of the switch unit, and a second end of the current measuring resistor is used to connect to one end of a heating element; A voltage-dividing resistor, wherein a first end of the voltage-dividing resistor is used to connect to an input end of the switch unit, and a second end of the voltage-dividing resistor is used to connect to a second end of the current measuring resistor; A voltage measurement point is provided at the second end of the current measuring resistor; the voltage measurement point is connected to a controller; The other end of the heating element is grounded.

9. The resistance measuring circuit according to claim 8, characterized in that: The controller is used to: Sending a control signal to the control terminal of the switch unit to turn on the switch unit; Obtaining a power supply voltage and a second voltage at a second end of the current measuring resistor; calculating the current of the current measuring resistor according to the voltage difference between the power supply voltage and the second voltage, the resistance value of the current measuring resistor and the resistance value of the switch unit; The resistance of the heating element is calculated according to the second voltage and the current of the current measuring resistor.

10. An electronic atomization device, characterized in that: The invention comprises a resistance measuring circuit as claimed in any one of claims 1 to 9.

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