Anti-dry-burning method and anti-dry-burning circuit of electronic cigarette

Abstract

The invention discloses an anti-dry-burning method of an electronic cigarette and an anti-dry-burning circuit of the electronic cigarette. The anti-dry-burning method comprises the following steps: S1, setting a cigarette liquid remaining amount threshold value L1 near dry burning, and setting a resistance value amplification first threshold value R1; s2, when the microprocessor detects that an atomizer of the electronic cigarette is inserted into a battery rod, a resistance value detection unit detects a heating resistor to obtain an initial resistance value R0; s3, during smoking at each time, the cigarette liquid remaining amount detection unit detects the cigarette liquid remaining amount real-time value L in real time, the resistance value detection unit detects the heating resistor in real time to obtain the real-time resistance value R, and the microprocessor subtracts the real-time resistance value R from the initial resistance value R0 to obtain the real-time change amplitude value R-R0 of the resistance value; and S4, when the microprocessor analyzes and judges that L is smaller than or equal to L1 and R-R0 is larger than or equal to R1, the microprocessor controls the power adjusting unit to immediately turn off output and forbids the power adjusting unit to supply power to the heating resistor again so as to carry out dry burning prevention protection. The method has the advantages that whether the electronic cigarette reaches the dry burning state or not can be accurately analyzed and judged, dry burning protection is carried out, and a user is prevented from inhaling electronic cigarette smoke with scorched smell.

Description

Technical Field

[0001] The present invention relates to the technical field of dry-burning prevention for electronic cigarettes. More specifically, the present invention relates to a dry-burning prevention method for an electronic cigarette and its dry-burning prevention circuit. Background Art

[0002] An electronic cigarette generally includes a battery rod and an atomizer. The atomizer includes an atomization device. After the heating resistor in the atomization device is energized, it generates heat. The e-liquid of the electronic cigarette in contact with the heating resistor is heated and atomized to form a steam-like smoke. The smoke flows through the smoke channel in the atomizer to the mouthpiece of the atomizer for the user to inhale.

[0003] During the actual use of an electronic cigarette, it may occur that when the e-liquid is exhausted or the e-liquid does not contact the heating resistor well, resulting in no e-liquid around the heating resistor when it is heating, only the heating resistor is in a "dry-burning" situation, which is likely to damage the electronic cigarette.

[0004] Existing electronic cigarettes generally include directly detecting the content of the e-liquid or detecting the resistance value of the heating resistor, that is, detecting the working temperature of the heating resistor to determine whether the electronic cigarette is in a "dry-burning" state, and then performing power-off protection. The existing dry-burning prevention protection methods for electronic cigarettes generally detect the absolute value of the resistance of the heating resistor, and when it is determined that its resistance value reaches the dry-burning protection setting value, the battery rod cuts off the power supply to the heating resistor for dry-burning prevention protection, or when it is determined that the rate of change of its resistance value within a certain time reaches the dry-burning protection setting value, the battery rod cuts off the power supply to the heating resistor for dry-burning prevention protection.

[0005] However, directly detecting the content of the e-liquid is difficult to accurately detect due to the shaking of the atomizer causing the liquid level of the e-liquid to keep changing, and directly detecting the working temperature of the heating resistor may also cause a temporary lack of e-liquid around the heating resistor when it is heating due to the poor contact between the e-liquid and the heating resistor, resulting in a short-term dry-burning. Therefore, these methods will cause inaccurate dry-burning judgments and result in dry-burning protection, making the electronic cigarette unable to continue to be used when there is still e-liquid, and there is no circuit that can accurately, real-time and conveniently detect and protect whether the atomizer has a real dry-burning. Summary of the Invention

[0006] The present invention provides a dry-burning prevention method for an electronic cigarette and its dry-burning prevention circuit to overcome the above technical deficiencies.

[0007] The technical solution of the present invention is realized as follows: A dry-burning prevention method for an electronic cigarette includes the following steps:

[0008] S1. In the circuit of the electronic cigarette, a heating resistor, a liquid level detection unit, a resistance value detection unit, a microprocessor, a start switch, and a power adjustment unit are electrically connected. A liquid level threshold L1 near dry burning is set, and a first threshold R1 for the increase in the resistance value of the heating resistor during dry burning is set;

[0009] S2. When the microprocessor detects that the atomizer of the electronic cigarette is plugged into the battery rod, the resistance value detection unit detects the initial resistance value R0 of the heating resistor;

[0010] S3. During each puff, the liquid level detection unit detects the real-time liquid level value L in real time and sends it to the microprocessor. The resistance value detection unit detects the real-time resistance value R of the heating resistor in real time and sends it to the microprocessor. The microprocessor subtracts the real-time resistance value R obtained during this period from the initial resistance value R0 to obtain the real-time change amplitude value of the resistance value as R - R0;

[0011] S4. When the microprocessor analyzes and determines that L ≤ L1 and R - R0 ≥ R1, the microprocessor controls the power adjustment unit to immediately turn off the output and prohibits it from supplying power to the heating resistor again for dry-burning protection.

[0012] Preferably, step S1 further includes: setting a second threshold R2 for the increase in the resistance value of the heating resistor that may cause dry burning, and setting R2 > R1; and further includes step S5: when the microprocessor analyzes and determines that L > L1 and R - R0 ≥ R2, the microprocessor controls the power adjustment unit to temporarily turn off the power supply to the heating resistor for temporary dry-burning protection.

[0013] Preferably, step S1 further includes: setting the power adjustment unit to constant power output, the liquid level detection unit includes a timer, and equivalently replacing the liquid level threshold L1 with a duration threshold T1 for the heating resistor to work; step S3 further includes: equivalently replacing the real-time liquid level value L with a duration threshold T for the heating resistor to work in real time; step S4 further includes: equivalently replacing the microprocessor's analysis and determination of L ≤ L1 with the analysis and determination of T ≤ T1.

[0014] Preferably, step S1 further includes: setting the power adjustment unit to constant power output, the liquid level detection unit includes a timer, and equivalently replacing the liquid level threshold L1 with a duration threshold T1 for the heating resistor to work; step S3 further includes: equivalently replacing the real-time liquid level value L with a duration threshold T for the heating resistor to work in real time; step S4 further includes: equivalently replacing the microprocessor's analysis and determination of L ≤ L1 with the analysis and determination of T ≤ T1; step S5 further includes: equivalently replacing the microprocessor's analysis and determination of L > L1 with the analysis and determination of T > T1.

[0015] Preferably, the value range of L1 is set to (0.5%-2%)L0, where L0 is the total value of the e-liquid, and the value range of R1 is set to 0.05Ω-0.9Ω.

[0016] Preferably, the value range of L1 is set to (0.5%-2%)L0, where L0 is the total value of the e-liquid, the value range of R1 is set to 0.05Ω-0.9Ω, and the value range of R2 is set to 0.09Ω-1.0Ω.

[0017] Preferably, the value range of L0 is set to 1ml-10ml.

[0018] Preferably, the value range of T1 is set to (0.5%-2%)T0, where T0 is the total working duration of the heating resistor, and the value range of R1 is set to 0.05Ω-0.9Ω.

[0019] Preferably, the value range of T1 is set to (0.5%-2%)T0, where T0 is the total working duration of the heating resistor, the value range of R1 is set to 0.05Ω-0.9Ω, and the value range of R2 is set to 0.09Ω-1.0Ω.

[0020] Preferably, the value range of T0 is set to 400 seconds-4000 seconds.

[0021] Another technical solution of the present invention is implemented as follows: A dry-burning prevention circuit for implementing a dry-burning prevention method of an electronic cigarette, including an electrically connected battery, a power adjustment unit, a microprocessor, a start switch, a sampling reference resistor, a resistance value detection unit, an e-liquid remaining amount detection unit, and an e-liquid data storage module. When the start switch is turned on or off, the microprocessor controls the power adjustment unit to output power to the heating resistor or turn off the output. The resistance value detection unit is used to detect the resistance value R of the heating resistor in real time and transmit it to the microprocessor. The e-liquid remaining amount detection unit is used to detect the real-time value L of the e-liquid remaining amount in the atomizer in real time and transmit it to the microprocessor. The e-liquid data storage module is used to store the initial resistance value R0, the resistance value R detected in real time, the real-time value L of the e-liquid remaining amount, and some initially set thresholds and data.

[0022] Another technical solution of the present invention is implemented as follows: An anti-dry-burning circuit for implementing an anti-dry-burning method of an electronic cigarette includes a battery, a power adjustment unit, a microprocessor, a start switch, a sampling reference resistor, a resistance value detection unit, a liquid level detection unit for the e-liquid, and an e-liquid data storage module, which are electrically connected. When the start switch is turned on or off, the microprocessor controls the power adjustment unit to output power to the heating resistor or cut off the output. The resistance value detection unit is used to detect the resistance value R of the heating resistor in real time and transmit it to the microprocessor. The liquid level detection unit for the e-liquid includes a timer, which is used to accumulate the working duration Ta of the heating resistor in real time and transmit it to the microprocessor. The e-liquid data storage module is used to store the initial resistance value R0, the resistance value R detected in real time, the real-time value T of the remaining working duration of the heating resistor, and some initially set thresholds and data.

[0023] Preferably, the anti-dry-burning circuit of the electronic cigarette further includes an anti-counterfeiting chip, which includes an anti-counterfeiting data storage module and an e-liquid data storage module.

[0024] The beneficial effects of the anti-dry-burning method and the anti-dry-burning circuit of the electronic cigarette of the present invention are as follows: By simultaneously detecting the remaining amount of the e-liquid of the electronic cigarette and the change amplitude value of the resistance during each puff, the present invention can accurately analyze and judge whether the electronic cigarette reaches the dry-burning state or the temporary dry-burning state, so as to respectively perform permanent dry-burning protection and temporary dry-burning protection, avoid the user from inhaling the e-cigarette smoke with a burnt smell, and improve the user's good usage experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the anti-dry-burning circuit of the electronic cigarette of the present invention Figure 1 ;

[0026] Figure 2 is the anti-dry-burning circuit of the electronic cigarette of the present invention Figure 2 ;

[0027] Figure 3 is the anti-dry-burning circuit of the electronic cigarette of the present invention Figure 3 ;

[0028] Figure 4 is a schematic diagram of the change in the resistance value of the heating resistor when the electronic cigarette of the present invention is working. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The electronic cigarette of the present invention is composed of a battery rod and an atomizer. The battery rod supplies power to the atomizer. Among them, the battery rod is detachably connected to the atomizer. The atomizer can be replaced after the e-liquid in it is consumed, and the battery rod can be reused multiple times.

[0031] The meanings of the expressions of the letters and symbols in the present invention are as follows:

[0032] L0 = total e-liquid volume value, L1 = e-liquid remaining threshold value, L = real-time e-liquid remaining value.

[0033] T0 = total duration, T1 = duration remaining threshold value, Ta = elapsed working duration, T = real-time duration remaining value.

[0034] R0 = initial resistance value, R1 = first resistance increase threshold value, R2 = second resistance increase threshold value, R = real-time resistance value.

[0035] Embodiment 1

[0036] As Figure 1As shown, the anti-dry-burning circuit for implementing the anti-dry-burning method of an electronic cigarette in this embodiment includes a battery rod circuit and an atomizer circuit. Among them, the atomizer circuit includes a heating resistor and a liquid level detection unit for the remaining liquid. The battery rod circuit includes a battery, a power regulation unit, a microprocessor, a liquid data storage module, a start switch, a sampling reference resistor, and a resistance value detection unit that are electrically connected. Among them, the microprocessor consists of a liquid information calculation module, a dry-burning judgment module, and a resistance value change judgment module, and these modules are part of the integrated circuit components with specific functions; the liquid level detection unit for the remaining liquid, the liquid data storage module, the resistance value detection unit, the power regulation unit, and the start switch are respectively communicatively connected to the microprocessor. When the start switch is turned on, the microprocessor controls the power regulation unit to output power to the heating resistor, and the heating resistor is energized to generate heat, and the electronic cigarette starts to work. When the start switch is turned off, the microprocessor controls the power regulation unit to cut off the output to the heating resistor, and the electronic cigarette enters the standby state. In the control circuit configuration of the electronic cigarette of the present invention, when the start switch is turned on, the power regulation unit does not immediately output power to the heating resistor, but there is a delay, and the delay time can usually be designed to be 10 - 100 milliseconds. In this embodiment, the start switch is an airflow sensor. Each time the user takes a puff, an inhalation airflow is generated inside the electronic cigarette, and the airflow sensor is triggered by sensing the inhalation airflow, and the start switch is turned on. When the user stops puffing, there is no inhalation airflow, so the airflow sensor cannot sense the airflow and is turned off. In other embodiments, the start switch can be a manual button switch, or a microphone or a pressure sensor, etc. When the airflow sensor or the pressure sensor or the microphone detects the airflow or negative pressure generated by the user's smoking in the air passage of the electronic cigarette, it can be triggered to control the power regulation unit to turn on the power supply of the heating resistor, and turn it off when the user stops puffing. The manual button switch is turned on when manually pressed and turned off when pressed again. The resistance value detection unit can detect the resistance value of the heating resistor in real time and transmit it to the microprocessor. The liquid data storage module can be used to store data such as the resistance value and duration detected in real time, as well as some preset thresholds and data. The liquid level detection unit for the remaining liquid is used to detect the remaining liquid level in the atomizer in real time, and the liquid level detection unit for the remaining liquid is a liquid level sensor for detecting the remaining liquid level in real time. The heating resistor of the electronic cigarette of the present invention is a positive temperature coefficient thermistor, that is, the higher the temperature, the greater its resistance value.

[0037] Embodiment 2

[0038] As Figure 2As shown in the figure, the anti-dry-burning circuit for implementing the anti-dry-burning method of an electronic cigarette in this embodiment, on the basis of the previous embodiment, the liquid level detection unit includes a timer, and this timer belongs to the detection unit that can detect and calculate the remaining liquid level of the e-liquid equally. Since there is a certain amount of e-liquid stored in the atomizer, under the condition of the same power, the heating resistor can consume it after working for a certain period of time. There is a corresponding relationship between the total value L0 of the e-liquid and the total duration T0 during which the e-liquid is consumed, that is, the total duration during which the heating resistor can work. The real-time value L of the remaining e-liquid is also corresponding to the real-time value T of the remaining working duration of the heating resistor. Therefore, detecting the remaining e-liquid can be equivalently replaced by detecting the remaining working duration of the heating resistor, that is, the liquid level detection unit can be specifically designed as a timer for detecting the working duration of the heating resistor. In addition, every time the user takes a puff of smoke, the start switch is turned on once, and then the heating resistor is powered on once, and the duration of the power-on is the duration of each puff of smoke, that is, the working duration of the start switch corresponds to the working duration of the heating resistor. Therefore, the timer can accumulate the working time of the start switch, that is, accumulate the already working duration Ta of the start switch (corresponding to the already working duration of the heating resistor) and send it to the microprocessor. If the set total working duration of the heating resistor is T0 (equivalent to the total value L0 of the e-liquid), the microprocessor can calculate the real-time value T of the remaining working duration of the heating resistor as T = T0 - Ta.

[0039] Embodiment III

[0040] As Figure 3 shown in the figure, the anti-dry-burning circuit for implementing the anti-dry-burning method of an electronic cigarette in this embodiment, on the basis of the previous embodiment, when the electronic cigarette battery rod and the atomizer are detachably connected, the atomizer circuit further includes an anti-counterfeiting chip. The anti-counterfeiting chip is originally used for anti-counterfeiting functions. Because it also has a storage module that can be utilized, the e-liquid data storage module can be transferred to the storage module in the anti-counterfeiting chip, that is, the anti-counterfeiting chip can include an anti-counterfeiting data storage module and an e-liquid data storage module, and also includes a data backup module and a data reading and writing processing module. The e-liquid data storage module can store e-liquid remaining data, setting data, and can also store data such as the already working duration data, the available working duration data of the heating resistor representing the e-liquid remaining, and setting data. The anti-counterfeiting chip in this embodiment uses an anti-counterfeiting chip with the model number XJX001.

[0041] For the existing anti-dry-burning methods of electronic cigarettes, generally, the absolute value of the resistance of the heating resistor is detected, and when it is judged that its resistance value reaches the dry-burning protection set value, the battery rod cuts off the power supply to the heating resistor for dry-burning protection, or when it is judged that the rate of change of its resistance value within a certain period of time reaches the dry-burning protection set value, the battery rod cuts off the power supply to the heating resistor for dry-burning protection.

[0042] The dry-burning prevention method of the electronic cigarette of the present invention includes temporary dry-burning prevention protection when the remaining amount of e-liquid is greater than the e-liquid remaining amount threshold L1 at the time approaching dry burning and permanent dry-burning prevention protection when the remaining amount of e-liquid is lower than or equal to the e-liquid remaining amount threshold L1 at the time approaching dry burning. In both cases, it is also necessary to determine whether the change in the heating resistance R within each puff by the user reaches a certain increase. If the set resistance increase is reached, it is determined as dry burning, and dry-burning protection or temporary dry-burning protection is performed.

[0043] Embodiment 4

[0044] As Figure 4 shown, T is the time axis and R is the resistance axis of the heating resistance. t0 is the time point when the atomizer of the electronic cigarette is plugged into the battery rod. t11 - t12, t21 - t22, and t31 - t32 are the times of each puff. The time points of t11, t21, and t31 are the time points when the start switch is turned on or the heating resistance is powered on. The time points of t12, t22, and t32 are the time points when the start switch is turned off or the heating resistance is powered off.

[0045] In this embodiment, a dry-burning prevention method for an electronic cigarette is provided, including the following steps:

[0046] S1. In the control circuit of the electronic cigarette, a heating resistance, an e-liquid remaining amount detection unit, a resistance detection unit, a microprocessor, a start switch, and a power adjustment unit are electrically connected. The e-liquid remaining amount threshold at the time approaching dry burning is set to L1 = 0.1 ml, and the first threshold of the resistance increase of the heating resistance when dry burning occurs is set to R1 = 0.12 Ω. Additionally, the total e-liquid amount value L0 = 10 ml can be set.

[0047] S2. When the microprocessor detects that the atomizer of the electronic cigarette is plugged into the battery rod, i.e., at time point t0, the resistance detection unit detects the initial resistance R0 of the heating resistance in real time.

[0048] S3. During each puff, the e-liquid remaining amount detection unit detects the real-time value L of the e-liquid remaining amount in real time and sends it to the microprocessor. The resistance detection unit detects the real-time resistance R of the heating resistance in real time and sends it to the microprocessor. The microprocessor subtracts the real-time resistance R obtained during this period from the initial resistance R0 to obtain the real-time change amplitude value of the resistance as R - R0.

[0049] S4. When the microprocessor analyzes and determines that L ≤ L1 and R - R0 ≥ R1, the microprocessor controls the power adjustment unit to immediately turn off the output and prohibit it from supplying power to the heating resistance again for dry-burning prevention protection.

[0050] In the above steps, when the microprocessor reads and determines that the real-time value L of the e-liquid remaining amount satisfies L ≤ L1, and reads and determines that the resistance change amplitude value R - R0 of the real-time resistance R during each puff of the user relative to the initial resistance R0 is greater than or equal to R1, that is, at this time, since the e-liquid in the atomizer is nearly insufficient, and the resistance change amplitude value during each puff has exceeded the set value, the microprocessor determines that the heating resistor has a real dry burn and controls the power adjustment unit to turn off the output and prohibits it from supplying power to the heating resistor again. In this way, it can accurately determine that the e-liquid in the atomizer is close to the minimum limit, and avoid continuously supplying power to the atomizer with little e-liquid, preventing the user from inhaling smoky with a burnt smell and causing an unpleasant user experience.

[0051] This method only needs to detect and set the initial resistance R0 once, without the need to detect the initial resistance R0 every time a puff is taken, making its working efficiency higher. This method is applicable to the situation where the initial resistance R0 changes little during each puff, that is, the initial resistance R0 of the heating resistor is relatively stable.

[0052] Embodiment 5

[0053] As Figure 4 shown, T is the time axis, and R is the resistance axis of the heating resistor. t0 is the time point when the atomizer of the electronic cigarette is plugged into the battery rod, t11 - t12, t21 - t22, t31 - t32 are the time of each puff, the time points of t11, t21, t31 are the time points when the start switch is turned on or the heating resistor is powered on, and the time points of t12, t22, t32 are the time points when the start switch is turned off or the heating resistor is powered off.

[0054] Based on Embodiment 4, a dry-burn prevention method for an electronic cigarette in this embodiment includes the following steps:

[0055] S1. In the control circuit of the electronic cigarette, set a heating resistor, an e-liquid remaining amount detection unit, a resistance detection unit, a microprocessor, an e-liquid data storage module, a start switch, and a power adjustment unit that are electrically connected. Set the e-liquid remaining amount threshold L1 = 0.1 ml when approaching dry burn, set the first threshold R1 = 0.12 Ω for the resistance increase of the heating resistor when dry burn occurs, set the second threshold R2 = 0.17 Ω for the resistance increase of the heating resistor that may cause dry burn, and another e-liquid total amount value L0 = 10 ml can be set.

[0056] S2. When the microprocessor detects that the atomizer of the electronic cigarette is plugged into the battery rod, that is, at the time point t0, the resistance detection unit detects the initial resistance R0 of the heating resistor in real time.

[0057] S3. During each puff, the e-liquid remaining amount detection unit detects the real-time value L of the e-liquid remaining amount in real time and sends it to the microprocessor. The resistance value detection unit detects the real-time resistance value R of the heating resistor in real time and sends it to the microprocessor. The microprocessor subtracts the real-time resistance value R obtained during this period from the initial resistance value R0 to obtain the real-time change amplitude value of the resistance value as R - R0.

[0058] S4. When the microprocessor analyzes and determines that L ≤ L1 and R - R0 ≥ R1, the microprocessor controls the power adjustment unit to immediately turn off the output and prohibits it from supplying power to the heating resistor again for dry-burning prevention protection.

[0059] S5. When the microprocessor analyzes and determines that L > L1 and R - R0 ≥ R2, the microprocessor controls the power adjustment unit to temporarily turn off the power supply to the heating resistor for temporary dry-burning prevention protection.

[0060] In the above steps, if the microprocessor reads and determines that the real-time value L of the e-liquid remaining amount ≤ L1, and reads and determines that the resistance change amplitude value R - R0 of the real-time resistance value R during each puff of the user relative to the initial resistance value R0 ≥ R1, that is, at this time, the e-liquid in the atomizer is nearly insufficient, and the resistance change amplitude value has exceeded the set threshold, so the microprocessor determines that the heating resistor has a real dry-burning and controls the power adjustment unit to turn off the output and prohibits it from supplying power to the heating resistor again. In this way, it can accurately determine that the e-liquid in the atomizer is close to the minimum limit, and avoid continuing to supply power to the atomizer with almost no e-liquid, and avoid the user inhaling smoky with a burnt smell and causing an unpleasant use experience.

[0061] At the same time, if the microprocessor reads and determines that the e-liquid remaining amount value L > L1, and reads and determines that the resistance change amplitude value R - R0 ≥ R2, that is, at this time, the e-liquid in the atomizer is still sufficient, but due to the different placement angles of the atomizer, the liquid supply is not timely or sufficient, resulting in a temporary lack of e-liquid around the heating resistor and causing a short-term dry-burning. Therefore, the microprocessor determines that the heating resistor may have a temporary dry-burning and controls the power adjustment unit to temporarily turn off the output, so that the heating resistor pauses working. If the liquid supply can be quickly restored around the heating resistor, when the user continues to puff and the detected resistance change amplitude value R - R0 < R2, the microprocessor controls the power adjustment unit to restore power supply to the heating resistor, and the electronic cigarette can continue to work. The microprocessor can accurately determine the temporary dry-burning of the heating resistor in this case and perform temporary dry-burning protection, and can also avoid the user inhaling smoky with a burnt smell and causing an unpleasant use experience.

[0062] Embodiment Six

[0063] As Figure 4As shown, T is the time axis and R is the resistance value axis of the heating resistor. t0 is the time point when the atomizer of the electronic cigarette is plugged into the battery rod. t11 - t12, t21 - t22, and t31 - t32 are the times for each puff. The time points of t11, t21, and t31 are the time points when the start switch is turned on or the heating resistor is powered on. The time points of t12, t22, and t32 are the time points when the start switch is turned off or the heating resistor is powered off.

[0064] Based on Embodiment 4, a dry - burning prevention method for an electronic cigarette in this embodiment includes the following steps:

[0065] S1. In the circuit of the electronic cigarette, a heating resistor, a liquid level detection unit, a resistance value detection unit, a micro - processor, a liquid data storage module, a start switch, and a power adjustment unit are electrically connected. The liquid level detection unit includes a timer. The power adjustment unit is set to output a constant power. A threshold value T1 = 35 seconds for the remaining working duration of the heating resistor when approaching dry - burning is set. A first threshold value R1 = 0.12Ω for the resistance value increase of the heating resistor when dry - burning occurs is set. Additionally, a total working duration T0 = 3500 seconds for the heating resistor can be set.

[0066] S2. When the micro - processor detects that the atomizer of the electronic cigarette is plugged into the battery rod, i.e., at time point t0, the resistance value detection unit detects the initial resistance value R0 of the heating resistor in real - time.

[0067] S3. During each puff, the timer detects the real - time value T of the remaining working duration of the heating resistor in real - time and sends it to the micro - processor. The resistance value detection unit detects the real - time resistance value R of the heating resistor in real - time and sends it to the micro - processor. The micro - processor subtracts the initial resistance value R0 from the real - time resistance value R obtained during this period to get the real - time change amplitude value of the resistance value as R - R0.

[0068] S4. When the micro - processor analyzes and determines that T ≤ T1 and R - R0 ≥ R1, the micro - processor controls the power adjustment unit to immediately turn off the output and prohibits it from supplying power to the heating resistor again for dry - burning prevention protection.

[0069] In the above steps, the e-liquid remaining amount detection unit includes a timer, and the detection of the e-liquid remaining amount is achieved by the method of timing with the timer. This timer belongs to the detection unit that can detect and calculate the e-liquid remaining amount equally. Since there is a certain amount of e-liquid stored in the atomizer, under the condition of the same power, the heating resistor can consume it after working for a certain period of time. There is a corresponding relationship between the total value L0 of the e-liquid and the total duration T0 during which the e-liquid is consumed, that is, the total working duration of the heating resistor. The real-time value L of the e-liquid remaining amount and the real-time value T of the remaining working duration of the heating resistor are also corresponding. Therefore, the detection of the e-liquid remaining amount can be equivalently replaced by detecting the remaining working duration of the heating resistor, that is, the e-liquid remaining amount detection unit can be specifically designed as a timer for detecting the working duration of the heating resistor. In addition, every time the user takes a puff of smoke, the start switch is turned on once, and then the heating resistor is powered on once. The duration of the power-on is the duration of each puff of smoke, that is, the working duration of the start switch corresponds to the working duration of the heating resistor. Therefore, the timer can accumulate the working time of the start switch, that is, accumulate the already working duration Ta of the start switch (corresponding to the already working duration of the heating resistor) and send it to the microprocessor. If the set total working duration of the heating resistor is T0 (which can be converted into the total value L0 of the e-liquid), the microprocessor can calculate the real-time value T of the remaining working duration of the heating resistor as T = T0 - Ta. The real-time value T of the remaining working duration of the heating resistor is equivalent to the real-time value L of the e-liquid remaining amount.

[0070] When the microprocessor reads and judges that the real-time value T of the remaining duration is less than or equal to T1, and reads and judges that the resistance change amplitude value R - R0 of the real-time resistance R during each puff of the user relative to the initial resistance R0 is greater than or equal to R1, that is, at this time, because the e-liquid in the atomizer is almost insufficient, and the resistance change amplitude value during each puff has exceeded the set value, the microprocessor judges that the heating resistor has a real dry burn and controls the power adjustment unit to turn off the output and prohibits it from supplying power to the heating resistor again. In this way, it can accurately judge that the e-liquid in the atomizer has approached the minimum limit, and avoid continuing to supply power to the atomizer with almost no e-liquid, so as to avoid the user inhaling smoky with a burnt smell and causing an unpleasant use experience. For example Figure 4 As shown, the timer can also be used to detect and calculate the time interval t between the turn-off of the start switch at the end of the previous puff and the turn-on at the start of the next puff.

[0071] Embodiment Seven

[0072] For example Figure 4 As shown, T is the time axis and R is the resistance axis of the heating resistor. t0 is the time point when the atomizer of the electronic cigarette is plugged into the battery rod. t11 - t12, t21 - t22, t31 - t32 are the times of each puff. The time points of t11, t21, t31 are the time points when the start switch is turned on or the heating resistor is powered on. The time points of t12, t22, t32 are the time points when the start switch is turned off or the heating resistor is powered off.

[0073] Based on Embodiment 5, a dry-burning prevention method for an electronic cigarette in this embodiment includes the following steps:

[0074] S1. In the circuit of the electronic cigarette, a heating resistor, a liquid level detection unit, a resistance value detection unit, a microprocessor, a liquid data storage module, a start switch, and a power adjustment unit are electrically connected. The liquid level detection unit includes a timer. The power adjustment unit is set to output a constant power. The remaining working time threshold T1 = 35 seconds for the heating resistor when approaching dry burning is set, and the first threshold for the resistance value increase of the heating resistor during dry burning is set as R1 = 0.12 Ω. Additionally, the total working time T0 = 3500 seconds that the heating resistor can work can be set.

[0075] S2. When the microprocessor detects that the atomizer of the electronic cigarette is plugged into the battery rod at time point t0, the resistance value detection unit detects the initial resistance value R0 of the heating resistor in real time.

[0076] S3. During each puff, the timer detects the real-time remaining working time value T of the heating resistor in real time and sends it to the microprocessor. The resistance value detection unit detects the real-time resistance value R of the heating resistor in real time and sends it to the microprocessor. The microprocessor subtracts the initial resistance value R0 from the real-time resistance value R obtained during this period to get the real-time change amplitude value of the resistance value as R - R0.

[0077] S4. When the microprocessor analyzes and determines that T ≤ T1 and R - R0 ≥ R1, the microprocessor controls the power adjustment unit to immediately turn off the output and prohibits it from supplying power to the heating resistor again for dry-burning protection.

[0078] S5. When the microprocessor analyzes and determines that T > T1 and R - R0 ≥ R2, the microprocessor controls the power adjustment unit to temporarily turn off the power supply to the heating resistor for temporary dry-burning protection.

[0079] In the above steps, the e-liquid remaining amount detection unit includes a timer, and the detection of the e-liquid remaining amount is achieved by timing with the timer. This timer belongs to the detection unit that can detect and calculate the e-liquid remaining amount equivalently. Since there is a certain amount of e-liquid stored in the atomizer, under the condition of the same power, the heating resistor can consume it after working for a certain period of time. There is a corresponding relationship between the total e-liquid amount value L0 and the total duration during which the e-liquid is consumed, that is, the total duration T0 during which the heating resistor can work. The real-time value L of the e-liquid remaining amount and the real-time value T of the remaining duration during which the heating resistor can work are also corresponding. Therefore, the detection of the e-liquid remaining amount can be equivalently replaced by detecting the remaining duration during which the heating resistor can work. That is, the e-liquid remaining amount detection unit can be specifically designed as a timer for detecting the working duration of the heating resistor. In addition, every time the user takes a puff of smoke, the start switch is turned on once, and then the heating resistor is powered on once, and the duration of the power-on is the duration of each puff of smoking, that is, the working duration of the start switch corresponds to the working duration of the heating resistor. Therefore, the timer can accumulate the working time of the start switch, that is, accumulate the already working duration Ta of the start switch (corresponding to the already working duration of the heating resistor) and send it to the microprocessor. If the set total working duration of the heating resistor is T0 (which can be converted into the total e-liquid amount value L0), the microprocessor can calculate the real-time value T of the remaining duration during which the heating resistor can work as T = T0 - Ta. The real-time value T of the remaining duration during which the heating resistor can work is equivalent to the real-time value L of the e-liquid remaining amount.

[0080] If the microprocessor reads and judges that the real-time value T of the e-liquid remaining amount ≤ T1, and reads and judges that the resistance change amplitude value R - R0 of the real-time resistance R during each puff of the user relative to the initial resistance R0 ≥ R1, that is, at this time, because the e-liquid in the atomizer is nearly insufficient, and the resistance change amplitude value during each puff has exceeded the set value, the microprocessor judges that the heating resistor has a real dry burn and controls the power adjustment unit to cut off the output and prohibits it from supplying power to the heating resistor again. In this way, it can accurately judge that the e-liquid in the atomizer is close to the minimum limit, and avoid continuing to supply power to the atomizer with almost no e-liquid, so as to prevent the user from inhaling the smoky smell and causing an unpleasant use experience.

[0081] Meanwhile, if the microprocessor reads and determines that the e-liquid remaining value T > T1, and reads and determines that the resistance change amplitude value R - R0 ≥ R2, that is, the e-liquid in the atomizer is still sufficient at this time, but due to the different placement angles of the atomizer, the liquid supply is not timely or sufficient, resulting in a temporary lack of e-liquid around the heating resistor and causing a temporary dry burn. Therefore, the microprocessor determines that the heating resistor may have a temporary dry burn and controls the power adjustment unit to temporarily turn off the output, so that the heating resistor stops working. If the liquid supply can be quickly restored around the heating resistor, when the user continues to inhale and the detected resistance change amplitude value R - R0 < R2, the microprocessor controls the power adjustment unit to restore power supply to the heating resistor, and the electronic cigarette can continue to work. In this case, the microprocessor can accurately judge the temporary dry burn of the heating resistor and perform temporary dry burn protection, and can also avoid the user inhaling the smoky smell and causing an unpleasant use experience.

[0082] In the above embodiment, the value range of L1 can be set to (0.5% - 2%)L0, the value range of R1 can be set to 0.05Ω - 0.9Ω, and the value range of R2 can be set to 0.09Ω - 1.0Ω; or the value range of T1 can be set to (0.5% - 2%)T0. Among them, the value range of L0 can be set to (1 - 10)ml, and the value range of T0 can be set to (400 - 4000) seconds.

[0083] The above description is only the preferred embodiment of the present invention, and the above specific embodiments are not limitations on the present invention. Within the scope of the technical idea of the present invention, various deformations and modifications can occur. Any retouching, modification or equivalent replacement made by those of ordinary skill in the art according to the above description belongs to the scope protected by the present invention.

Claims

1. A method for preventing dry burning of an electronic cigarette, characterized in that: The following steps are involved: S1. In the circuit of the electronic cigarette, a heating resistor, a smoke liquid remaining amount detection unit, a resistance value detection unit, a microprocessor, a start switch and a power adjustment unit are electrically connected, and a smoke liquid remaining amount threshold L1 when dry burning is approaching is set, and a first threshold value R1 of the resistance value increase of the heating resistor when dry burning occurs is set; S2, when the microprocessor detects that the atomizer of the electronic cigarette is plugged into the battery rod, the resistance detection unit detects the heating resistor to obtain an initial resistance R0; S3, during each puff, the smoke liquid remaining amount detection unit detects in real time to obtain the real-time value L of the smoke liquid remaining amount and sends it to the microprocessor, the resistance value detection unit detects in real time the heating resistor to obtain the real-time resistance value R and sends it to the microprocessor, and the microprocessor subtracts the real-time resistance value R obtained during this period from the initial resistance value R0 to obtain the real-time change amplitude value of the resistance value R-R0; S4. When the microprocessor analyzes and determines that L≤L1 and R-R0≥R1, the microprocessor controls the power regulating unit to immediately shut down the output and prohibits it from supplying power to the heating resistor again to perform anti-dry burning protection.

2. The method for preventing dry burning of an electronic cigarette according to claim 1, characterized in that: The step S1 also includes: setting the second threshold value of the resistance increase of the heating resistor where dry burning may occur to R2, and setting R2 to be greater than R1; and also includes step S5: when the microprocessor analyzes and determines that L>L1 and R-R0≥R2, the microprocessor controls the power regulation unit to temporarily shut down the power output to the heating resistor to perform temporary anti-dry burning protection.

3. The method for preventing dry burning of an electronic cigarette according to claim 1, characterized in that: The step S1 also includes: setting the power adjustment unit to a constant power output, the smoke liquid remaining detection unit includes a timer, and the smoke liquid remaining threshold value L1 is equivalently replaced by the remaining threshold value T1 of the working time of the heating resistor; the step S3 also includes: replacing the real-time value L of the smoke liquid remaining with the real-time value T of the working time of the heating resistor; the step S4 also includes: equivalently replacing the microprocessor analyzing and judging L≤L1 with analyzing and judging T≤T1.

4. The method for preventing dry burning of an electronic cigarette according to claim 2, characterized in that: The step S1 also includes: setting the power adjustment unit to a constant power output, the smoke liquid remaining detection unit includes a timer, and the smoke liquid remaining threshold value L1 is equivalently replaced by the remaining threshold value T1 of the working time of the heating resistor; the step S3 also includes: replacing the real-time value L of the smoke liquid remaining by the real-time value T of the working time of the heating resistor; the step S4 also includes: replacing the microprocessor's analysis and judgment of L≤L1 by equivalently replacing it with analysis and judgment of T≤T1; the step S5 also includes: replacing the microprocessor's analysis and judgment of L>L1 by analysis and judgment of T>T1.

5. The method for preventing dry burning of an electronic cigarette according to claim 1, characterized in that: The value range of L1 is set to (0.5%-2%) L0, where L0 is the total value of the smoke liquid, and the value range of R1 is set to 0.05Ω-0.9Ω.

6. The method for preventing dry burning of an electronic cigarette according to claim 2, characterized in that: The value range of L1 is set to (0.5%-2%) L0, where L0 is the total value of the smoke liquid, the value range of R1 is set to 0.05Ω-0.9Ω, and the value range of R2 is set to 0.09Ω-1.0Ω.

7. The method for preventing dry burning of an electronic cigarette according to claim 5 or 6, characterized in that: Set the value range of L0 to 1ml-10ml.

8. The method for preventing dry burning of an electronic cigarette according to claim 3, characterized in that: The value range of T1 is set to (0.5%-2%)T0, where T0 is the total working time of the heating resistor, and the value range of R1 is set to 0.05Ω-0.9Ω.

9. The method for preventing dry burning of an electronic cigarette according to claim 4, characterized in that: The value range of T1 is set to (0.5%-2%)T0, where T0 is the total working time of the heating resistor, the value range of R1 is set to 0.05Ω-0.9Ω, and the value range of R2 is set to 0.09Ω-1.0Ω.

10. The method for preventing dry burning of an electronic cigarette according to claim 8 or 9, characterized in that: Set the value range of T0 to 400 seconds-4000 seconds.

11. An anti-dry burning circuit for realizing the anti-dry burning method of the electronic cigarette according to any one of claims 1-2, characterized in that: The invention comprises an electrically connected battery, a power regulating unit, a microprocessor, a start switch, a sampling reference resistor, a resistance detection unit, a smoke liquid remaining detection unit and a smoke liquid data storage module. When the start switch is turned on or off, the microprocessor controls the power regulating unit to output power to the heating resistor or shuts off the output. The resistance detection unit is used to detect the resistance R of the heating resistor in real time and transmit it to the microprocessor. The smoke liquid remaining detection unit is used to detect the real-time value L of the smoke liquid remaining in the atomizer in real time and transmit it to the microprocessor. The smoke liquid data storage module is used to store the initial resistance R0, the resistance R detected in real time, the real-time value L of the smoke liquid remaining and some thresholds and data set initially.

12. An anti-dry burning circuit for implementing the anti-dry burning method of an electronic cigarette as claimed in any one of claims 3 to 4, characterized in that: The invention comprises an electrically connected battery, a power regulating unit, a microprocessor, a start switch, a sampling reference resistor, a resistance detection unit, a smoke liquid remaining detection unit and a smoke liquid data storage module. When the start switch is turned on or off, the microprocessor controls the power regulating unit to output power to the heating resistor or shuts off the output. The resistance detection unit is used to detect the resistance R of the heating resistor in real time and transmit it to the microprocessor. The smoke liquid remaining detection unit comprises a timer. The timer is used to accumulate the working time Ta of the heating resistor in real time and transmit it to the microprocessor. The smoke liquid data storage module is used to store the initial resistance R0, the resistance R detected in real time, the real-time value T of the remaining working time of the heating resistor and some threshold values ​​and data set initially.

13. The anti-dry burning circuit of the electronic cigarette according to claim 12, characterized in that: The control circuit also includes an anti-counterfeiting chip, and the anti-counterfeiting chip includes an anti-counterfeiting data storage module and a smoke liquid data storage module.

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