WO2019033886A1

WO2019033886A1 - Dry-burning prevention device of electronic cigarette, and dry-burning prevention control method therefor

Info

Publication number: WO2019033886A1
Application number: PCT/CN2018/096056
Authority: WO
Inventors: 林光榕; 郑贤彬
Original assignee: 惠州市新泓威科技有限公司
Priority date: 2017-08-15
Filing date: 2018-07-18
Publication date: 2019-02-21
Also published as: CN107440157B; CN107440157A

Abstract

A dry-burning prevention device of an electronic cigarette and a dry-burning prevention control method therefor. A microcontroller of the dry-burning prevention device is electrically connected, in sequence, to a half-bridge boost circuit, a chopped-wave buck circuit, an atomizer and an atomizer resistance-value detection module, and is then connected back to the microcontroller from same; feedback circuits are respectively connected between the chopped-wave buck circuit and the atomizer and between the chopped-wave buck circuit and the half-bridge boost circuit, and the feedback circuits both access the micro controller; the feedback circuits respectively feed back output voltage signals of the half-bridge boost circuit and the chopped-wave buck circuit, so as to adjust output voltages of the half-bridge boost circuit and the chopped-wave buck circuit and keep the output voltages stable; and when an electronic cigarette is working, the atomizer resistance-value detection module continuously detects a resistance value of the atomizer according to a set interval time of the microcontroller, and when the resistance value of the atomizer exceeds a set dry-burning prevention resistance value and the number of continuous exceeding times reaches a preset number of times, the microcontroller instructs the half-bridge boost circuit or the chopped-wave buck circuit to close the output, and the electronic cigarette automatically stops working.

Description

Anti-drying device for electronic cigarette and anti-dry burning control method

Technical field

The invention relates to the field of electronic cigarette technology, in particular to an anti-dry burning device for an electronic cigarette and an anti-dry burning control method.

Background technique

The existing electronic cigarette generally comprises a nozzle, a casing and a liquid storage device, an atomization component, a power source and a circuit control board which are arranged in the casing, and no anti-dry protection module is provided. In the existing electronic cigarettes, after the liquid smoke is used up, it is necessary to manually add the liquid smoke or replace the liquid storage device, so that the use can continue. When the liquid smoke in the liquid storage device is used up, the user does not add the liquid liquid or replace the liquid storage in time. When the device continues to smoke, the circuit controlled by the circuit board continues to work, so that the heating unit in the atomizing assembly is dry-burned due to a sudden increase in temperature due to lack of smoke liquid, thereby generating harmful gas and burnt smell to be inhaled into the human body, which is harmful. Human health, in addition to the rapid heat generated to the rest of the electronic cigarette is also easy to burn electronic cigarettes or burn human skin.

technical problem

SUMMARY OF THE INVENTION An object of the present invention is to provide an anti-drying device for an electronic cigarette which does not dry out when the smoke liquid in the electronic cigarette liquid storage device is used up and the user continues to smoke. Another object of the present invention is to provide a control method for preventing dry burning of an electronic cigarette having an anti-dry protection function.

Technical solution

The technical solution of the present invention is an anti-drying device for the electronic cigarette, which is special in that it comprises a microcontroller, a half-bridge boost circuit, a chopper step-down circuit, an atomizer, and an atomizer resistance detection. a module, a battery power supply circuit, the battery power supply circuit comprising a switch and a rechargeable battery, wherein the microcontroller is electrically connected to the half bridge boost circuit, the chopper buck circuit, the atomizer, and the atomizer resistance The detection module is then connected back to the microcontroller, and a first feedback circuit is connected between the chopper buck circuit and the nebulizer, and a connection between the chopper buck circuit and the half bridge boost circuit is a second feedback circuit, the first feedback circuit and the second feedback circuit are respectively connected to the microcontroller, the microcontroller is electrically connected to the chopper buck circuit; and the second feedback circuit feeds back the output voltage signal of the half bridge boost circuit So that the microcontroller adjusts the output voltage of the half-bridge boost circuit and keeps it stable, the first feedback circuit feeds back the output voltage signal of the chopper buck circuit, so that the microcontroller adjusts the output voltage of the chopper buck circuit and keeps stable; When the electronic cigarette works, the atomizer resistance detecting module continuously detects the resistance of the atomizer according to the interval of the interval of the microcontroller, and when the resistance of the atomizer continuously exceeds the resistance set by the dry burning protection and continuously exceeds When the number of times reaches the set number of times, the microcontroller instructs the half-bridge boost circuit or the chopper buck circuit to turn off the output, and the electronic cigarette stops working.

Preferably, the atomizer is electrically connected to the current detecting module, and the current detecting module and the atomizer resistance detecting module are respectively connected to the short circuit detecting module, and the short circuit detecting module is connected to the microcontroller.

Preferably, the method further includes: a charging circuit, a charger, and a charger voltage detecting module, wherein the microcontroller is electrically connected to the charging circuit, and the charger is electrically connected to the charger voltage detecting module and then connected to the microcontroller, wherein the charger further And sequentially connecting the charging circuit and the battery power supply circuit to supply power to the microcontroller and the half bridge boosting circuit respectively; the microcontroller is further connected to the LED control module, the switch detecting module and the auxiliary boosting module, respectively, the auxiliary boosting module The half bridge boost circuit is connected.

Preferably, a temperature sensor and a battery temperature detecting module are further disposed. When charging, the temperature sensor detects a temperature signal of the battery and accesses the battery temperature detecting module, and then accesses the microcontroller through the battery power supply circuit. When the temperature signal exceeds the set temperature range value, the microcontroller instructs the charging circuit to stop charging; when the temperature sensor detects that the temperature signal exceeds the set temperature range value during the discharge, the microcontroller commands the half bridge boost circuit or chopping The step-down circuit turns off the output and the electronic cigarette stops working.

Preferably, the half-bridge boosting circuit comprises a main control chip U ₃ , an inductor L ₁ , a capacitor C ₁ and a capacitor C ₂ , the main control chip U ₃ includes a fourth pin VSW, and the fourth pin VSW is inductive. L _{1 is} respectively connected to the capacitor C ₂ , one end of the capacitor C ₁ and the battery positive BAT+, and the other ends of the capacitor C ₂ and the capacitor C ₁ are grounded; the half-bridge boost circuit further includes a capacitor C ₃ and a capacitor C ₄ . The chip U ₃ includes a fifth pin VIN, and the fifth pin VIN is respectively connected to the capacitor C ₃ , one end of the capacitor C ₄ and the half bridge output terminal VOUT , and the other end of the capacitor C ₃ and the capacitor C ₄ Grounding; the main control chip U ₃ internally includes two N-MOS tubes, and the main control chip U _{3 is} provided with an eighth pin PWM for inputting a PWM-IN signal of a first set frequency, and PWM-IN signal control The two N-MOS transistors reach the boost voltage, and the output voltage of the fifth pin VIN is outputted to the half-bridge output terminal VOUT, and the frequency of the PWM-IN signal is adjusted by the signal of the second feedback circuit to make the half-bridge output terminal VOUT The voltage is stabilized to the set voltage V ₁ .

Preferably, the chopper buck circuit comprises a MOS transistor Q ₂ , a resistor R ₁₈ , a triode Q ₃ , a resistor R ₂₀ , a pull-down resistor R ₇ , a chopper buck output terminal PWM_OUT, and a second set frequency output terminal OUT_PWM the half-bridge output terminal VOUT are electrically connected to the MOS transistor Q ₂ source electrode S, a resistor R _18, R ₁₈ access the resistance of the MOS transistor Q ₂ and the gate G ₃₃ of the collector of transistor Q, MOS tube the drain D Q output terminal of the step-down chopper access PWM_OUT _2, wherein the emitter _of transistor Q 2 is grounded, the base of transistor Q 1 through ₃ of the electrode ₂₀ are respectively connected after the resistor R and one end of the pull-down resistor R ₇ 2. The output terminal OUT_PWM of the set frequency; the output terminal OUT_PWM of the second set frequency is connected to the microcontroller, and the other end of the pull-down resistor R ₇ is grounded.

Advantageously: the nebulizer resistance detection module includes a positive battery BAT +, MOS tube Q _1, MOS tube Q _4, a resistor R _12, a resistor R _14, test switch TEST_R, the reference resistor R _15, a resistor R _16, a resistor R ₁₇ , the resistor R ₂₁ and the capacitor C ₁₇ , the microcontroller R_DET end, the battery positive BAT + is respectively connected to the source 2 of the MOS transistor Q ₁ and the resistor R ₁₂ , the other end of the resistor R ₁₂ and the gate of the MOS transistor Q ₁ respectively a pole 1, a gate 1 of the MOS transistor Q ₄ and a resistor R ₁₄ , the other end of the resistor R ₁₄ is connected to the test switch TEST_R, the drain 3 of the MOS transistor Q ₁ is connected to the drain 3 of the MOS transistor Q ₄ , and the MOS transistor Q ₄ source 2 series reference resistor R ₁₅ , resistor R _{16 is} connected to the microcontroller R_DET terminal, the junction between the reference resistor R ₁₅ and the resistor R ₁₆ is connected to the chopper buck output terminal PWM_OUT and the resistor R _{17 respectively} . The other end of the resistor R ₁₇ is grounded, and the junction between the resistor R ₁₆ and the end of the microcontroller R_DET is respectively connected to the resistor R ₂₁ , the capacitor C ₁₇ , the other end of the resistor R ₂₁ and the capacitor C ₁₇ is grounded; TEST_R controller turns the test switch signal, the closure MOS transistor Q ₁ and Q _4, while the microcontroller detecting micro-control based on the reference resistance R ₁₅ AD voltage value R_DET terminal calculates the reference current value flowing through the resistor R _15, and then calculate the resistance of the resistor nebulizer.

Preferably, the short circuit detecting module comprises a resistor R ₁₉ , a resistor R ₂₂ , a capacitor C ₁₅ , a CON1 terminal, a nebulizer negative pole F−, a short circuit detection point SHORT_DET, and a short circuit between the short circuit detection point SHORT_DET and the CON1 terminal. The resistor R ₁₉ , the short circuit detection point SHORT_DET is also connected to the capacitor C ₁₅ , the other end of the capacitor C ₁₅ is grounded, the CON1 terminal is also connected to the F- and the resistor R ₂₂ respectively, and the other end of the resistor R ₂₂ is grounded; The short circuit detecting module detects the voltage drop across the short circuit resistor R ₂₂ , and then detects the current value of the short circuit detecting point SHORT_DET through the microcontroller and determines whether the short circuit protection set current value is exceeded. If the voltage exceeds, the half bridge is closed by the microcontroller. The output of the boost circuit or chopper buck circuit stops the electronic cigarette.

Advantageously: the first frequency is set to 100K ~ 300KHz, the voltage V ₁ is set to 3.0 ~ 5.5V.

Preferably, the second set frequency is 30 to 100 Hz.

Preferably, the dry burn protection set resistance is 0.05 to 6.0 ohms, and the set number of times is at least 1 time.

Another technical solution of the present invention is an anti-dry control method for the anti-drying device of the electronic cigarette, which is special in that it comprises the following steps:

(1) When the electronic cigarette starts to work, the microcontroller determines whether the time when the switch is closed exceeds the set time, if not, proceeds to step (10), and if so, proceeds to the next step;

(2) The microcontroller controls the output voltage of the chopper step-down circuit;

(3) The microcontroller counts the resistance of the atomizer continuously exceeding the resistance set by the dry burn protection to zero;

(4) The microcontroller starts timing and determines whether the interval setting time for measuring the resistance of the atomizer is reached. If not, the timer is continued and judged, and if yes, the process proceeds to the next step;

(5) The microcontroller command atomizer resistance detecting module detects the resistance of the atomizer;

(6) After detecting the resistance of the atomizer, the microcontroller determines whether the resistance of the atomizer exceeds the resistance setting of the dry burn protection, and if not, returns to step (3), and if so, enters Next step;

(7) The microcontroller controls the resistance value of the atomizer in the previous step to continuously exceed the number of times the dry resistance protection resistance is set to +1;

(8) The microcontroller determines whether the cumulative number of consecutive resistance values exceeding the dry burn protection setting reaches the set number of times, if not, returns to step (4), and if yes, proceeds to the next step;

(9) The microcontroller determines that the state of the electronic cigarette is a dry burn state;

(10) Turn off the output of the half-bridge boost circuit or the chopper buck circuit, and the electronic cigarette stops working.

Beneficial effect

The electronic cigarette is provided with an anti-drying device, wherein a half bridge boosting circuit, a chopper stepping circuit and an atomizer resistance detecting module are provided, and the resistance value of the heating body resistance in the atomizer can be detected. The atomizer continues to work due to the lack of smoke liquid. When the temperature rises sharply and the resistance of the atomizer exceeds the set value of the dry burn protection and the number of consecutive times exceeds the set number of times, the electronic cigarette anti-drying device makes Judging and timely cutting off the power output of the half-bridge boost circuit or the chopper buck circuit to prevent the atomizer from dry burning, thereby preventing harmful gases and burnt smell from being inhaled into the human body and endangering human health, and avoiding the electronic cigarette being burnt out or Burns the body.

DRAWINGS

1 is a circuit block diagram of an anti-drying device for an electronic cigarette of the present invention;

2 is a circuit schematic diagram of a half bridge booster circuit of the present invention;

3 is a circuit schematic diagram of a chopper step-down circuit of the present invention;

Figure 4 is a circuit schematic diagram of the atomizer resistance detecting module of the present invention;

Figure 5 is a circuit schematic diagram of the short circuit detecting module of the present invention;

Fig. 6 is a flow chart showing the control method of the electronic cigarette dry prevention according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention will be further described in detail below with reference to the accompanying drawings:

Fig. 1 shows an anti-drying device for an electronic cigarette of the present invention.

Referring to FIG. 1 , the anti-drying device for the electronic cigarette of the present invention comprises a microcontroller, that is, an MCU, a half-bridge boosting circuit, a chopper step-down circuit, an atomizer, an atomizer resistance detecting module, and a battery power supply. The circuit, the battery power supply circuit comprises a switch and a rechargeable battery (not shown), and the microcontroller MCU is electrically connected to the half bridge boost circuit, the chopper buck circuit, the atomizer, the atomizer resistance detection module, and then Returning to the microcontroller, a first feedback circuit is connected between the chopper buck circuit and the nebulizer, and a second feedback circuit is connected between the chopper buck circuit and the half bridge boost circuit, and the first feedback circuit And the second feedback circuit is respectively connected to the microcontroller, the micro-controller is electrically connected to the chopper buck circuit; the second feedback circuit feeds back the output voltage signal of the half-bridge boost circuit, so that the microcontroller adjusts the output of the half-bridge boost circuit The voltage is kept stable, and the first feedback circuit feeds back the output voltage signal of the chopper step-down circuit, so that the microcontroller adjusts the output voltage of the chopper step-down circuit and remains stable; when the electronic cigarette works, the atomizer resistance detection module According to micro The interval set by the controller is set to continuously detect the resistance of the atomizer, that is, the atomizer resistance detecting module detects the resistance of the atomizer according to the interval setting time, for example, every 20 milliseconds, when the detected fog When the resistance of the device continuously exceeds the dry resistance setting resistance value such as 2 ohms and continuously exceeds the set resistance value to reach the set number of times, for example, 5 times, the microcontroller commands the chopper step-down circuit to turn off the output, and the electronic cigarette automatically stops. jobs. The above-mentioned setting detection resistance value continuously exceeds the dry burning protection setting resistance value and continuously exceeds the set resistance value to reach the set number of times, which is to avoid unnecessary occurrence of nebulizer resistance value and unnecessary dry burning protection. . Because sometimes there is smoke in the e-cigarette that does not dry out, there are occasional factors that cause the atomizer resistance measured occasionally one or two times to exceed the set resistance of the dry burn protection. If this happens, start dry. The work of burning off the electronic cigarettes is obviously not in line with the actual situation, which brings a bad user experience. Only when the resistance value of the atomizer detected continuously for more than one time exceeds the set resistance value of the dry burn protection and reaches the set number of times, can the true situation of the dry burn be truly reflected, and the dry burn can be performed after the shutdown. protection.

In the anti-drying device of the electronic cigarette of the present invention, the atomizer includes a thermistor wire (not shown) in the heat generating unit, and the resistance of the thermistor wire changes with temperature, so that the resistance value can be detected. Calculate the corresponding temperature value.

Referring to FIG. 1 , the atomizer is also electrically connected to the current detecting module, and the current detecting module and the atomizer resistance detecting module are respectively connected to the short circuit detecting module, and the short circuit detecting module is connected to the microcontroller. The short-circuit detection module is used to detect whether the thermal heating wire of the atomizer is short-circuited. If a short circuit occurs, the microcontroller can instruct the half-bridge boost circuit or the chopper buck circuit to turn off the output for protection, and the electronic cigarette stops working. The half-bridge boost circuit supplies power to the chopper buck circuit. When the half-bridge boost circuit is turned off, the chopper buck circuit is also turned off.

Referring to FIG. 1 , the electronic cigarette anti-drying device further includes a charging circuit, a charger, and a charger voltage detecting module. The microcontroller is electrically connected to the charging circuit, and the charger is electrically connected to the charger voltage detecting module and then connected. The microcontroller and the charger are also electrically connected to the charging circuit and the battery power supply circuit, respectively, and then supply power to the microcontroller and the half-bridge boosting circuit respectively; the microcontroller is also respectively connected with the LED control module, the switch detection module and the auxiliary boosting module, and the auxiliary The boost module is connected to the half bridge boost circuit. The auxiliary boost module is used to assist the boost of the half-bridge boost circuit. The charging voltage detection module operates during charging to prevent overcharging of the charger. The LED control module is used for controlling the LED indicator to indicate different brightness or different colors or combinations thereof for the smoking state. The switch detection module is used for detecting the closed state or the closing time of the button switch, and the auxiliary boosting module is used for compensation or auxiliary lifting. The buck bridge circuit is used for better boosting.

Referring to FIG. 1 , the anti-drying device of the electronic cigarette of the present invention further comprises a temperature sensor and a battery temperature detecting module. When charging, the temperature sensor detects the temperature signal of the battery and connects to the battery temperature detecting module, and then is powered by the battery. The circuit is connected to the microcontroller. When the temperature signal exceeds the set temperature range, the microcontroller commands the charging circuit to stop charging. When the temperature sensor detects that the temperature signal exceeds the set temperature range, the microcontroller commands the half bridge. The boost circuit or the chopper buck circuit turns off the output and the electronic cigarette stops working. The battery temperature detection module is used to detect the temperature during battery charging and discharging, and to avoid the risk of damage or explosion if the battery temperature is too high.

Referring to FIG. 2, the half-bridge boost circuit includes a main control chip U ₃ , an inductor L ₁ , a capacitor C _{1 ,} and a capacitor C ₂ . The main control chip U ₃ includes a fourth pin VSW, and the fourth pin VSW is inductive. L _{1 is} respectively connected to the capacitor C ₂ , one end of the capacitor C ₁ and the battery positive BAT+, the other end of the capacitor C ₂ and the capacitor C ₁ are grounded; the half bridge boost circuit further includes a capacitor C ₃ and a capacitor C ₄ , wherein the chip U ₃ includes the 5th pin VIN, the 5th pin VIN is respectively connected to the capacitor C ₃ , one end of the capacitor C ₄ and the half bridge output terminal VOUT , the other end of the capacitor C ₃ and the capacitor C ₄ are grounded; the main control chip U ₃ internal Including two N-MOS tubes, the main control chip U _{3 is} provided with an eighth pin PWM for inputting a PWM-IN signal of a first set frequency, and the PWM-IN signal controls two N-MOS tubes to achieve boosting, VIN pin 5 to the half-bridge output voltage output terminal VOUT, by simultaneously adjusting the frequency of the signal PWM-iN signal of the second feedback circuit, a half bridge voltage output terminal VOUT is stabilized to the set voltage V _1, the first set The frequency is 100 K to 300 KHz, and the set voltage V ₁ is 3.0 to 5.5 V.

Referring to FIG. 3, the chopper buck circuit includes a MOS transistor Q ₂ , a resistor R ₁₈ , a triode Q ₃ , a resistor R ₂₀ , a pull-down resistor R ₇ , a chopper buck output terminal PWM_OUT, and a second set frequency output. end OUT_PWM, half-bridge output terminal VOUT are electrically connected to the MOS transistor Q ₂ source electrode S, a resistor R _18, R ₁₈ access the resistance MOS transistor Q ₂ and the gate G ₃₃ of the collector of transistor Q, MOS transistor Q ₂ the drain D of the output of the step-down chopper access PWM_OUT, electrode 2 is grounded emitter transistor Q ₃ and the transistor Q ₃ of the base electrode 1 after ₂₀ respectively connected via a resistor R one end of the pull-down resistor R ₇ and the second frequency setting The output terminal OUT_PWM of the second set frequency is connected to the microcontroller, and the other end of the pull-down resistor R ₇ is grounded, and the second set frequency is 30-100 Hz.

Please refer to FIG. 4, an atomizer includes a resistance detection module battery positive electrode BAT +, MOS tube Q _1, MOS tube Q _4, a resistor R _12, a resistor R _14, test switch TEST_R, the reference resistor R _15, a resistor R _16, Resistor R ₁₇ , resistor R ₂₁ and capacitor C ₁₇ , microcontroller R_DET terminal, battery positive BAT+ are respectively connected to source 2 of MOS transistor Q ₁ and resistor R ₁₂ , and the other end of resistor R ₁₂ is respectively connected to the gate of MOS transistor Q ₁ . The pole 1 and the gate 1 of the MOS transistor Q ₄ and the resistor R ₁₄ , the other end of the resistor R ₁₄ is connected to the test switch TEST_R, the drain 3 of the MOS transistor Q _{1 and} the drain 3 of the MOS transistor Q ₄ are connected, and the MOS transistor Q ₄ The source 2 series reference resistor R ₁₅ and the resistor R _{16 are} connected to the R_DET terminal of the microcontroller, and the junction between the reference resistor R ₁₅ and the resistor R ₁₆ is respectively connected to the chopper buck output terminal PWM_OUT and the resistor R ₁₇ , and the resistor R The other end of ₁₇ is grounded, and the junction between the resistor R ₁₆ and the end of the microcontroller R_DET is respectively connected to the resistor R ₂₁ , the capacitor C ₁₇ , and the other end of the resistor R ₂₁ and the capacitor C ₁₇ is grounded; the detection resistor of the present invention detects the current To achieve. When measuring dry burning, the microcontroller turns on the test switch TEST_R signal, closes the MOS transistors Q ₁ and Q ₄ , and the microcontroller calculates the AD voltage value at the terminal R_DET of the microcontroller according to the reference resistor R ₁₅ to calculate the flow through the reference resistor R _{15 .} The current value, then calculate the resistance value of the atomizer, determine whether the resistance value of the atomizer exceeds the set resistance value of the dry burn protection, and continuously exceed the set number of the dry burn protection set resistance value. In the burning state, the microcontroller will cut off the PWM_OUT output of the chopper buck output terminal, and the electronic cigarette stops working. The above dry burning protection set resistance is 0.05-6.0 ohm, which exceeds the dry burning protection setting resistance. The number of settings is at least 1 time.

Referring to FIG. 5, the short-circuit detection module includes a resistor R ₁₉ , a resistor R ₂₂ , a capacitor C ₁₅ , a CON1 terminal, a nebulizer negative pole F-, a short-circuit detection point SHORT_DET, and a series resistance R between the short-circuit detection point SHORT_DET and the CON1 terminal. ₁₉ , the short-circuit detection point SHORT_DET is also connected to the capacitor C ₁₅ , the other end of the capacitor C ₁₅ is grounded, the CON1 terminal is also connected to the F- and the resistor R _{22 respectively} , the other end of the resistor R ₂₂ is grounded; the short-circuit detection module detects the short-circuit resistance R ₂₂ The voltage drop is detected by the microcontroller to detect the current value of the short-circuit detection point SHORT_DET and determine whether the short-circuit protection set current value is exceeded. If it exceeds, the output of the half-bridge boost circuit or the chopper buck circuit is turned off by the microcontroller. The electronic cigarette automatically stops working.

Please refer to FIG. 6 , which shows an anti-dry control method for an anti-drying device for an electronic cigarette according to the present invention, comprising the following steps:

(1) When the electronic cigarette starts to work, the microcontroller determines whether the time when the switch is closed exceeds the set time, such as 0.3 seconds, if not, proceeds to step (10), and if so, proceeds to the next step;

In this step, the switch closing time does not exceed the set switching time of 0.3 seconds, indicating that the switch is accidentally touched, the chopper step-down circuit does not output, and the atomizer heating unit of the electronic cigarette does not work, and it exceeds 0.3 seconds. Switch closure is an artificial operation.

In this step, the output voltage signal of the chopper step-down circuit, that is, the atomizer starts to work.

(4) The microcontroller starts timing and determines whether the interval setting time for measuring the resistance of the atomizer is 20 milliseconds. If not, it continues to count and judge, and if yes, proceeds to the next step;

In this step, the resistance is measured because the resistance of the heating unit needs to be measured at intervals, and the interval is set to 20 ms in the microcontroller.

In this step, as shown in FIG. 4, the microcontroller turns on the test switch TEST_R signal, closes the MOS transistors Q ₁ and Q ₄ , and the microcontroller simultaneously calculates the AD voltage value of the microcontroller R_DET terminal according to the reference resistor R ₁₅ to calculate the flow. After the current value of R ₁₅ , the resistance value of the atomizer is calculated; the resistance of the atomizer resistance detection module is realized by detecting the current.

(6) After detecting the resistance value of the atomizer, the microcontroller determines whether the resistance value of the atomizer exceeds the dry resistance setting resistance value such as 2.5 ohms, and if not, returns to step (3), and if so, Go to the next step;

This step accumulates the number of times the measured resistance continuously exceeds the set resistance.

(8) The microcontroller determines whether the cumulative number of consecutive resistance values exceeding the dry burn protection setting reaches the set number of times, for example, 5 times. If not, returns to step (4), and if yes, proceeds to the next step;

In this step, only when the resistance value of the atomizer detected multiple times exceeds the set resistance of the dry burn protection and reaches the set number of times, it indicates that the atomizer lacks the smoke liquid and dry burning occurs.

Industrial applicability

The above are only the preferred embodiments of the present invention, and all changes and modifications made within the scope of the claims of the present invention should be construed as the scope of the claims.

Claims

An anti-drying device for an electronic cigarette, comprising: a microcontroller, a half bridge boosting circuit, a chopper stepping circuit, an atomizer, an atomizer resistance detecting module, a battery power supply circuit, and the battery The power supply circuit includes a switch and a rechargeable battery, and the microcontroller is electrically connected to the half bridge boost circuit, the chopper buck circuit, the atomizer, the atomizer resistance detection module, and then connected back to the microcontroller. a first feedback circuit is connected between the chopper step-down circuit and the atomizer, and a second feedback circuit is connected between the chopper buck circuit and the half-bridge boost circuit, the first The feedback circuit and the second feedback circuit are respectively connected to the microcontroller, and the microcontroller is electrically connected to the chopper buck circuit; the second feedback circuit feeds back the output voltage signal of the half bridge boost circuit, so that the microcontroller adjusts the half bridge The output voltage of the voltage circuit is kept stable, and the first feedback circuit feeds back the output voltage signal of the chopper step-down circuit, so that the microcontroller adjusts the output voltage of the chopper step-down circuit and remains stable; when the electronic cigarette works, the fog Resistance value The measuring module continuously detects the resistance value of the atomizer according to the interval of the interval of the microcontroller, and when the resistance value of the atomizer continuously exceeds the resistance setting value of the dry burning protection and the number of consecutive times exceeds the set number of times, the microcontroller The half-bridge boost circuit or the chopper buck circuit is turned off to output the electronic cigarette.
The anti-drying device for an electronic cigarette according to claim 1, wherein the atomizer is further electrically connected to the current detecting module, and the current detecting module and the atomizer resistance detecting module are respectively connected to the short-circuit detecting The module, the short circuit detection module is connected to the microcontroller.
The anti-drying device for an electronic cigarette according to claim 1, further comprising a charging circuit, a charger, and a charger voltage detecting module, wherein the microcontroller is electrically connected to the charging circuit, and the charger is electrically connected to the charger After the voltage detecting module is connected to the microcontroller, the charger is further electrically connected to the charging circuit and the battery power supply circuit, and then supplies power to the microcontroller and the half bridge boosting circuit respectively; the microcontroller is also respectively connected to the LED control module, A switch detection module and an auxiliary boost module, the auxiliary boost module being connected to the half bridge boost circuit.
The anti-drying device for an electronic cigarette according to claim 1, further comprising a temperature sensor and a battery temperature detecting module, wherein when charging, the temperature sensor detects a temperature signal of the battery and accesses the battery temperature detecting module And then accessing the microcontroller through the battery power supply circuit, when the temperature signal exceeds the set temperature range value, the microcontroller instructs the charging circuit to stop charging; when discharging, the temperature sensor detects that the temperature signal exceeds the set temperature range At the time of the value, the microcontroller instructs the half-bridge boost circuit or the chopper buck circuit to turn off the output, and the electronic cigarette stops working.
The anti-drying device for an electronic cigarette according to claim 1, wherein the half-bridge boosting circuit comprises a main control chip U 3 , an inductor L 1 , a capacitor C 1 and a capacitor C 2 , and the main control chip U 3 comprises The fourth pin VSW, the fourth pin VSW is connected to the capacitor C 2 , one end of the capacitor C 1 and the battery positive BAT+ via the inductor L 1 , and the other ends of the capacitor C 2 and the capacitor C 1 are grounded; The half-bridge boost circuit further includes a capacitor C 3 and a capacitor C 4 , wherein the chip U 3 includes a fifth pin VIN, and the fifth pin VIN is respectively connected to the capacitor C 3 , one end of the capacitor C 4 and a half bridge The output terminal VOUT, the other end of the capacitor C 3 and the capacitor C 4 are grounded; the main control chip U 3 internally includes two N-MOS tubes, and the main control chip U 3 is provided with an eighth pin PWM for inputting A set frequency of the PWM-IN signal, the PWM-IN signal controls the two N-MOS transistors to reach the boost, and the output voltage of the fifth pin VIN is outputted to the half-bridge output terminal VOUT while passing the signal of the second feedback circuit. Adjust the frequency of the PWM-IN signal to stabilize the voltage at the half-bridge output VOUT to the set voltage V 1 .
The anti-drying device for an electronic cigarette according to claim 5, wherein the chopper step-down circuit comprises a MOS transistor Q 2 , a resistor R 18 , a triode Q 3 , a resistor R 20 , a pull-down resistor R 7 , and a chopper The buck output terminal PWM_OUT and the second set frequency output terminal OUT_PWM, the half bridge output terminal VOUT is electrically connected to the source S of the MOS transistor Q 2 and the resistor R 18 , respectively, and the resistor R 18 is connected to the MOS transistor Q 2 . the gate G and the collector of transistor Q 33, and the drain of the MOS transistor Q D output of the step-down chopper access PWM_OUT 2, wherein the emitter of transistor Q 2 is grounded, the base of transistor Q 3 via the electrode 1 The resistor R 20 is respectively connected to one end of the pull-down resistor R 7 and the output terminal OUT_PWM of the second set frequency; the output terminal OUT_PWM of the second set frequency is connected to the microcontroller, and the other end of the pull-down resistor R 7 Ground.
The electronic cigarette is 6 anti-dry apparatus as claimed in claim, wherein said nebulizer comprises a resistance detection module battery positive electrode BAT +, MOS tube Q 1, MOS tube Q 4, a resistor R 12, a resistor R 14, The test switch TEST_R, the reference resistor R 15 , the resistor R 16 , the resistor R 17 , the resistor R 21 and the capacitor C 17 , and the microcontroller R_DET terminal, the battery positive terminal BAT+ are respectively connected to the source 2 of the MOS transistor Q 1 and the resistor R 12 . , the other end of the resistor R 12, respectively, and the gate of the MOS transistor Q 1 1, the gate of the MOS transistor Q and the resistor R 4 to 14, the other end of the resistor R 14 connected to the test switch TEST_R, the drain of the MOS transistor Q 1 3 and 4, the MOS transistor Q 3 is connected to the drain, source MOS transistor Q 4 of the electrode 2 of the reference resistor R 15 connected in series, the junction between the resistor R 16 microcontroller R_DET access terminal, the reference resistor and the resistor R 16 R 15 The points are respectively connected to the chopper buck output terminal PWM_OUT and the resistor R 17 , the other end of the resistor R 17 is grounded, and the junction between the resistor R 16 and the end of the microcontroller R_DET is respectively connected to the resistor R 21 , the capacitor C 17 , and the resistor R 21 . and the other end of the capacitor C 17; when measured dry, micro-controller turns the test switch signal TEST_R closure MOS transistor Q 1 and Q 4 The microcontroller AD voltage value of the reference resistor R 15 is detected while the microcontroller calculates R_DET end value of the current flowing through the reference resistor R 15, and then calculate the resistance of the resistor nebulizer.
The anti-drying device for an electronic cigarette according to claim 2, wherein the short-circuit detecting module comprises a resistor R 19 , a resistor R 22 , a capacitor C 15 , a CON1 terminal, a nebulizer negative pole F-, and a short-circuit detection point SHORT_DET The series resistance R 19 between the short circuit detection point SHORT_DET and the CON1 terminal, the short circuit detection point SHORT_DET is also connected to the capacitor C 15 , the other end of the capacitor C 15 is grounded, and the CON1 terminal is also respectively connected to F- And the resistor R 22 , the other end of the resistor R 22 is grounded; the short circuit detecting module detects the voltage drop on the short circuit resistor R 22 , and then detects the current value of the short circuit detecting point SHORT_DET through the microcontroller and determines whether the short circuit protection is exceeded. Set the current value. If it exceeds, the output of the half-bridge boost circuit or the chopper buck circuit is turned off by the microcontroller, and the electronic cigarette stops working.
5 according to the electronic cigarette of anti-dry apparatus as claimed in claim, wherein said first frequency is set to 100K ~ 300KHz, the voltage V 1 is set to 3.0 ~ 5.5V.
The anti-drying device for an electronic cigarette according to claim 6, wherein the second set frequency is 30 to 100 Hz.
The anti-drying device for an electronic cigarette according to claim 7, wherein the dry burn protection set resistance is 0.05 to 6.0 ohms, and the set number of times is at least 1 time.
An anti-dry control method for an anti-drying device for an electronic cigarette according to any one of claims 1 to 11, characterized in that it comprises the following steps:

(1) When the electronic cigarette starts to work, the microcontroller determines whether the time when the switch is closed exceeds the set time, if not, proceeds to step (10), and if so, proceeds to the next step;

(2) The microcontroller controls the output voltage of the chopper step-down circuit;

(3) The microcontroller counts the resistance of the atomizer continuously exceeding the resistance set by the dry burn protection to zero;

(4) The microcontroller starts timing and determines whether the interval setting time for measuring the resistance of the atomizer is reached. If not, the timer is continued and judged, and if yes, the process proceeds to the next step;

(5) The microcontroller command atomizer resistance detecting module detects the resistance of the atomizer;

(6) After detecting the resistance of the atomizer, the microcontroller determines whether the resistance of the atomizer exceeds the resistance setting of the dry burn protection, and if not, returns to step (3), and if so, enters Next step;

(7) The microcontroller controls the resistance value of the atomizer in the previous step to continuously exceed the number of times the dry resistance protection resistance is set to +1;

(8) The microcontroller determines whether the cumulative number of consecutive resistance values exceeding the dry burn protection setting reaches the set number of times, if not, returns to step (4), and if yes, proceeds to the next step;

(9) The microcontroller determines that the state of the electronic cigarette is a dry burn state;

(10) Turn off the output of the half-bridge boost circuit or the chopper buck circuit, and the electronic cigarette stops working.