WO2019033887A1

WO2019033887A1 - Dry-burning prevention device of electronic cigarette and control method therefor

Info

Publication number: WO2019033887A1
Application number: PCT/CN2018/096061
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: CN107404107A; CN107404107B

Abstract

The present invention relates to a dry-burning prevention device of an electronic cigarette and a control method therefor. The dry-burning prevention device of an electronic cigarette comprises a microcontroller, a boost-buck bridge circuit, an atomizer resistance-value sampling circuit, an atomizer, an atomizer resistance-value detection module and a battery power supplying circuit. The microcontroller is electrically connected, in sequence, to the boost-buck bridge circuit, the atomizer resistance-value sampling circuit, the atomizer and the atomizer resistance-value detection module, and is then connected back to the microcontroller from same; the atomizer resistance-value sampling circuit is further electrically connected to the atomizer resistance-value detection module; a feedback circuit is connected between the atomizer resistance-value sampling circuit and the boost-buck bridge circuit, and the feedback circuit is connected back to the microcontroller, such that the microcontroller adjusts an output voltage of the boost-buck bridge circuit and keeps the output voltage stable; and when a cigarette liquid of an electronic cigarette is to be exhausted during use, and the atomizer resistance-value detection module detects the number of set times when the resistance value of the atomizer continuously exceeds a set dry-burning prevention resistance value, the microcontroller instructs the boost-buck bridge circuit to close the output, and the electronic cigarette automatically stops working.

Description

Anti-drying device for electronic cigarette and control method thereof

Technical field

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

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 module in the atomizing assembly is dry-burned due to the lack of smoke liquid, and the harmful gas and the burnt smell are 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 an anti-dry control method having an anti-drying device.

Technical solution

The technical solution of the present invention comprises: a microcontroller, a buck-boost bridge circuit, a nebulizer resistance sampling circuit, an atomizer, an atomizer resistance detecting module, a battery power supply circuit, and the battery power supply circuit includes a switch And the rechargeable battery, the microcontroller is electrically connected to the buck-boost bridge circuit, the atomizer resistance sampling circuit, the atomizer, the atomizer resistance detecting module, and then connected back to the microcontroller, the atomizing The resistance value sampling circuit is further electrically connected to the atomizer resistance detecting module, and a feedback circuit is connected between the atomizer resistance sampling circuit and the buck-boost bridge circuit, and the feedback circuit is connected back to the microcontroller. So that the microcontroller adjusts the output voltage of the buck-boost bridge circuit and keeps it stable; when the electronic cigarette works, the atomizer resistance detection module continuously detects the resistance of the atomizer according to the interval of the microcontroller setting time, when the fog When the resistance value of the chemicalizer continuously exceeds the resistance value set by the dry burning protection and the number of consecutive times exceeds the set number of times, the microcontroller commands the lifting and lowering bridge circuit to turn off the output, and the electronic cigarette automatically stops working.

Preferably, the method further includes: a short circuit detecting module, wherein the atomizer is 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 the microcontroller is connected, and the charger is in turn The charging circuit and the battery power supply circuit are electrically connected, and the battery power supply circuit supplies power to the microcontroller and the buck-boost bridge circuit, respectively.

Preferably, the microcontroller is electrically connected to the LED control module and the auxiliary boost module, respectively, and the auxiliary boost module is connected to the buck-boost circuit.

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 atomizer resistance detecting module comprises an operational amplifier U ₄ , a resistor R ₁₆ , a resistor R ₁₇ , a capacitor C ₁₂ , a resistor R ₁₉ , a capacitor C ₁₃ , a resistor R ₂₂ , a capacitor C _{14 ,} and a capacitor C ₁₅ . the atomizer sampling circuit comprises a resistor the resistance R _18, the operational amplifier U ₄ having a first pin REF, a second pin GND, a third pin VCC, fourth pins IN +, IN fifth pin - and the sixth pin OUT, the fourth pin IN+ of the operational amplifier U ₄ is connected to the capacitor C ₁₂ and the resistor R ₁₇ respectively, and then connected to the output terminal VOUT of the buck-boost circuit, and the fifth pin IN- is respectively connected to the capacitor C ₁₂ And the resistor R _{16 is} connected to the atomizer output terminal PWM-OUT, the connection between the resistor R ₁₆ and the atomizer output terminal PWM-OUT and the connection between the resistor R ₁₇ and the output of the buck-boost circuit circuit VOUT Connect the resistor R ₁₈ between the points, the sixth pin OUT of the operational amplifier U4 is connected to the resistor R _{19 and} then respectively connect the current detection signal IDET and the capacitor C ₁₃ , the other end of the capacitor C _{13 is} grounded, and the first pin of the operational amplifier U ₄ REF and the second pin GND are grounded. The third pin of the operational amplifier U ₄ is connected to the resistor R _{22 and} then connected to the auxiliary boost VCC-12V. The junction between the third pin VCC and the resistor R ₂₂ is respectively connected. The capacitor C ₁₅ and the capacitor C ₁₄ , the capacitor C ₁₅ and the other end of the capacitor C ₁₄ are grounded; when the current passes through the resistor R ₁₈ , the resistor R ₁₈ is divided across the resistor, and is performed through the resistor R ₁₆ , the resistor R ₁₇ , and the capacitor C ₁₂ . A filter is input to the operational amplifier U ₄ , and the operational amplifier U ₄ amplifies the filtered voltage and filters through the resistor R ₁₉ and the capacitor C ₁₃ , and then calculates the resistance of the atomizer through the current detection signal IDET.

Preferably, the buck-boost bridge circuit comprises a chip U ₁ , a chip U ₂ , MOS transistors Q ₁ and Q ₂ , MOS transistors Q ₃ and Q ₄ , a first Zener diode, a second Zener diode, and a resistor R ₁ The resistor R ₂ , the resistor R ₃ , the capacitor C ₁ , the capacitor C ₃ , the capacitor C ₂ , the capacitor C ₄ and the inductor L ₁ , the first pin VCC of the chip U ₁ is connected to the capacitor C ₃ and grounded, the chip U ₁ The third pin HO is connected to the gate of the MOS transistor Q ₂ , the tenth pin LO of the chip U ₁ is connected to the gate of the MOS transistor Q ₁ , and the first pin of the chip U ₂ is connected to the capacitor C ₄ After grounding, the third pin HO of the chip U ₂ is connected to the gate of the MOS transistor Q ₃ , the tenth pin LO of the chip U ₂ is connected to the gate of the MOS transistor Q ₄ , and the fourth pin HS of the chip U ₁ The fourth pin HS of the chip U ₂ is connected through the inductor L ₁ , and the second pin of the chip U ₁ is respectively connected to the Zener diode D ₁ and the capacitor C ₁ , and the other end of the capacitor C _{1 is} connected to the fourth lead of the chip U ₁ . foot HS, the other end of the Zener diode D ₁ of the first U-chip access pin VCC _1, a chip U ₂ are respectively connected to the second pin Zener diode D _2, the capacitor C _2, the other end of the capacitor C ₂ chip access U ₂ 's fourth pin HS, regulated diode The other end of the access tube chip D ₂ U VCC ₂ of the first pin, chip and chip U ₁ U ₂ each are grounded VSS ninth pin, an eighth pin boost chip U IN ₁ is connected to the microcontroller The signal terminal PWM-UP of the output frequency, the eighth pin IN of the chip U ₂ is connected to the signal terminal PWM-DN of the buck output frequency of the microcontroller, and the seventh pin EN of the chip U ₁ and the chip U ₂ are connected. The output control signal terminal PWM-EN of the buck-boost bridge, the seventh pin EN of the chip U ₂ and the output control signal terminal PWM-EN are connected to the resistor R ₃ and grounded, and the sixth pin RDT of the chip U ₁ is connected. After the resistor R _{1 is} grounded, the sixth pin RDT of the chip U ₂ is connected to the resistor R ₂ and grounded; when the battery voltage is lower than the output voltage, the buck-boost circuit of the buck-boost driver chip U ₂ outputs a signal to turn on the MOS transistor Q ₃ . The chip U ₁ and the MOS transistors Q ₁ and Q _{2 are} connected through the inductor L ₁ , and the boost driving chip U ₁ drives the MOS transistor Q ₁ and the Q ₂ boost output VOUT through the PWM output PWM-UP control signal of the microcontroller; when a voltage higher than the output voltage, the buck boost driver chip bridge circuit output signal U ₁ open MOS transistor Q _2, the chip is connected through an inductor L ₁ U _2, MOS tube Q ₄ and Q _{3. The} buck driver chip U ₂ drives the MOS transistor Q ₄ and the Q ₃ buck output VOUT through the PWM output PWM-DN control signal.

Another technical solution of the present invention is the control method of the electronic cigarette anti-dry burning, 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 causes the voltage rise and fall bridge circuit to output a voltage signal;

(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 buck-boost bridge circuit, and the electronic cigarette stops working.

Beneficial effect

The electronic cigarette is provided with an anti-drying device, wherein a buck-boost bridge circuit, a nebulizer resistance sampling circuit and an atomizer resistance detecting module are arranged, and the resistance value of the heating body resistance in the atomizer can be detected. When the atomizer continues to work due to the lack of smoke liquid, when the temperature rises sharply, the resistance of the atomizer exceeds the resistance set of the dry burn protection and the number of consecutive times exceeds the set number of times, the electronic cigarette is prevented from dry burning. The device makes a judgment and cuts off the power output of the buck-boost bridge circuit in time to prevent the atomizer from being dry-burned, thereby preventing harmful gas and burnt smell from being inhaled into the human body and endangering human health, and preventing the electronic cigarette from being burned or burned.

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 resistance detecting module of the atomizer of the present invention;

Figure 3 is a circuit schematic diagram of the buck-boost bridge circuit of the present invention;

4 is a flow chart of the electronic cigarette anti-dry control method of 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.

Please refer to FIG. 1 , the anti-drying device of the electronic cigarette of the invention comprises a microcontroller, a buck-boost bridge circuit, a nebulizer resistance sampling 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, and the microcontroller is electrically connected to the buck-boost bridge circuit, the atomizer resistance sampling circuit, the atomizer, the atomizer resistance detection module, and then connected back to the microcontroller. The atomizer resistance sampling circuit is also electrically connected to the atomizer resistance detecting module, and a feedback circuit is connected between the atomizer resistance sampling circuit and the buck-boost bridge circuit, and the feedback circuit is connected back to the microcontroller for micro control Adjusting the output voltage of the buck-boost bridge circuit and maintaining stability; when the electronic cigarette is working, the atomizer resistance detecting module continuously detects the resistance of the atomizer according to the interval time of the microcontroller, when the atomizer When the resistance value continuously exceeds the set value of the dry burn protection and the number of consecutive times exceeds the set number of times, the microcontroller commands the lift-buckle circuit to turn off the output, and the electronic cigarette automatically stops working. 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 anti-drying device of the electronic cigarette of the present invention further comprises a short-circuit detecting module, the atomizer is 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 thermistor wire of the atomizer is short-circuited. If a short circuit occurs, the microcontroller can instruct the buck-boost bridge circuit to turn off the output for protection, and the electronic cigarette stops working.

Referring to FIG. 1 , the anti-drying device of the electronic cigarette of the present invention further comprises a charging circuit, a charger, a charger voltage detecting module, a micro-controller electrically connecting the charging circuit, and the charger is electrically connected to the charger voltage detecting module. Into the microcontroller, the charger is electrically connected to the charging circuit and the battery power supply circuit in turn, and the battery power supply circuit supplies power to the microcontroller and the buck-boost bridge circuit respectively. The charging voltage detection module operates during charging to prevent overcharging of the charger.

Referring to FIG. 1 , in the anti-drying device of the electronic cigarette of the present invention, the microcontroller is electrically connected to the LED control module and the auxiliary boosting module respectively, and the auxiliary boosting module is connected to the lifting and lowering bridge circuit. 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 atomizer resistance detection module includes an operational amplifier U ₄ , a resistor R ₁₆ , a resistor R ₁₇ , a capacitor C ₁₂ , a resistor R ₁₉ , a capacitor C ₁₃ , a resistor R ₂₂ , a capacitor C _{14 ,} and a capacitor C. ₁₅ , the atomizer resistance sampling circuit comprises a resistor R ₁₈ , the operational amplifier U ₄ has a first pin REF, a second pin GND, a third pin VCC, a fourth pin IN+, a fifth pin IN- and The sixth pin OUT, the fourth pin IN+ of the operational amplifier U ₄ is respectively connected to the capacitor C ₁₂ and the resistor R _{17 and} then connected to the output terminal VOUT of the buck-boost circuit, and the fifth pin IN- is respectively connected to the capacitor C ₁₂ and the resistor. After R _{16 is} connected to the output of the atomizer PWM-OUT, the connection between the resistor R ₁₆ and the atomizer output PWM-OUT and the connection between the resistor R ₁₇ and the output of the buck-boost circuit VOUT Connect the resistor R ₁₈ , the sixth pin OUT of the operational amplifier U4 is connected to the resistor R _{19 and} then respectively connect the current detection signal IDET and the capacitor C ₁₃ , the other end of the capacitor C _{13 is} grounded, the first pin REF of the operational amplifier U ₄ and a second ground pin GND, a third operational amplifier pin VCC U ₄ is connected to the resistor R ₂₂ access auxiliary boost VCC-12V, the junction between the resistor ₂₂ and the third pin VCC of capacitor C ₁₅ are connected to R Capacitor C _14, the capacitor C ₁₅ and the capacitor C _14, the other end grounded; when the current through the resistor R _18, the both ends of the resistor R ₁₈ will divide the voltage, performed through the resistor R _16, a resistor R _17, a filter capacitor C ₁₂ then enter To the operational amplifier U ₄ , the operational amplifier U ₄ amplifies the filtered voltage and filters it through the resistor R ₁₉ and the capacitor C ₁₃ , and then calculates the resistance of the atomizer through the current detection signal IDET.

Referring to FIG. 3, the buck-boost circuit includes a chip U ₁ , a chip U ₂ , MOS transistors Q ₁ and Q ₂ , MOS transistors Q ₃ and Q ₄ , a first Zener diode, a second Zener diode, and a resistor. R ₁ , resistor R ₂ , resistor R ₃ , capacitor C ₁ , capacitor C ₃ , capacitor C ₂ , capacitor C ₄ and inductor L ₁ , the first pin VCC of chip U ₁ is connected to capacitor C ₃ and grounded, chip U ₁ The third pin HO is connected to the gate of the MOS transistor Q ₂ , the tenth pin LO of the chip U ₁ is connected to the gate of the MOS transistor Q ₁ , and the first pin of the chip U ₂ is connected to the capacitor C ₄ and grounded. The third pin HO of the chip U ₂ is connected to the gate of the MOS transistor Q ₃ , the tenth pin LO of the chip U ₂ is connected to the gate of the MOS transistor Q ₄ , and the fourth pin HS of the chip U ₁ is passed through the inductor ₁ U L access chips HS ₂ of the fourth pin, the second pin chip U ₁ are connected to _a Zener diode D, capacitor C _1, the other end of the capacitor C ₁ U chip access the fourth pin of the HS ₁ , the other end of the Zener diode D ₁ of the first U-chip access pin VCC _1, a chip U ₂ are respectively connected to the second pin Zener diode D _2, the capacitor C _2, the other end of the capacitor C ₂ U ₂ chip access the fourth pin HS, another Zener diode D ₂ A first end of the access pin VCC ₂ U chip, the chip U ₁ and U ₂ each chip ninth pin VSS are grounded, the output frequency of the signal boost eighth chip U IN ₁ pin is connected to the microcontroller Terminal PWM-UP, the eighth pin IN of the chip U ₂ is connected to the signal terminal PWM-DN of the buck output frequency of the microcontroller, and the seventh pin EN of the chip U ₁ and the chip U ₂ are connected to the buck-boost bridge The output control signal terminal PWM-EN, the chip U ₂ seventh pin EN and the output control signal terminal PWM-EN line junction connection resistor R _{3 is} grounded, the sixth pin RDT of the chip U ₁ is connected to the resistor R ₁ Grounding, the sixth pin RDT of the chip U ₂ is connected to the resistor R ₂ and grounded; when the battery voltage is lower than the output voltage, the buck-boost circuit circuit bucks the driving chip U ₂ output signal to turn on the MOS transistor Q ₃ , through the inductor L ₁ Connecting the chip U ₁ , the MOS transistors Q ₁ and Q ₂ , the boosting driving chip U ₁ drives the MOS transistor Q ₁ and the Q ₂ boosting output VOUT through the PWM output PWM-UP control signal; otherwise, when the battery voltage is higher than the output At voltage, the buck-boost circuit boosts the chip U ₁ output signal to turn on the MOS transistor Q ₂ , connects the chip U ₂ , the MOS transistors Q ₄ and Q ₃ through the inductor L ₁ , and steps down The driving chip U ₂ drives the MOS transistor Q ₄ and the Q ₃ step-down output VOUT through the microcontroller output PWM-DN control signal.

Referring to FIG. 4, the method for controlling the electronic cigarette dry prevention of the present invention 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, such as 0.3 milliseconds, 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.

(2) The microcontroller outputs a voltage signal to the output terminal VOUT of the buck-boost bridge circuit;

In this step, the output voltage signal of the buck-boost bridge 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 set to 3 milliseconds. If not, the timer is continued and judged, and if yes, the next step is entered;

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 3 ms in the microcontroller.

In this step, the nebulizer resistance detecting module detects the resistance 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 0.75 ohm, 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.

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 buck-boost bridge circuit, a nebulizer resistance sampling circuit, an atomizer, an atomizer resistance detecting module, a battery power supply circuit, The battery power supply circuit comprises a switch and a rechargeable battery, and the microcontroller is electrically connected to the buck-boost bridge circuit, the atomizer resistance sampling circuit, the atomizer, the atomizer resistance detection module, and then connected back to the micro control. The atomizer resistance sampling circuit is further electrically connected to the atomizer resistance detecting module, and a feedback circuit is connected between the atomizer resistance sampling circuit and the buck-boost bridge circuit, and the feedback circuit Reconnecting the microcontroller, so that the microcontroller adjusts the output voltage of the buck-boost circuit and keeps it stable; when the electronic cigarette is working, the atomizer resistance detecting module continuously detects the atomizer according to the interval of the microcontroller setting time. The resistance value, when the resistance of the atomizer continuously exceeds the set value of the dry burn protection and the number of consecutive times exceeds the set number of times, the microcontroller instructs the buck-boost circuit to turn off the output, and the electronic cigarette automatically stops working.
The anti-drying device for an electronic cigarette according to claim 1, further comprising a short circuit detecting module, wherein the atomizer is connected to the short circuit detecting module, and the short circuit detecting 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. The voltage detecting module is then connected to the microcontroller, and the charger is electrically connected to the charging circuit and the battery power supply circuit in sequence, and the battery power supply circuit supplies power to the microcontroller and the buck-boost bridge circuit, respectively.
The anti-drying device for an electronic cigarette according to claim 1, wherein the microcontroller is electrically connected to the LED control module and the auxiliary boosting module, respectively, and the auxiliary boosting module is connected to the buck-boost bridge 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 atomizer resistance detecting module comprises an operational amplifier U 4 , a resistor R 16 , a resistor R 17 , a capacitor C 12 , a resistor R 19 , and a capacitor C 13 , a resistor R 22 , a capacitor C 14 and a capacitor C 15 , the atomizer resistance sampling circuit includes a resistor R 18 , the operational amplifier U 4 has a first pin REF, a second pin GND, and a third Pin VCC, fourth pin IN+, fifth pin IN- and sixth pin OUT, the fourth pin IN+ of the operational amplifier U 4 is connected to the capacitor C 12 and the resistor R 17 respectively, and then connected to the buck-boost circuit The output terminal VOUT, the fifth pin IN- is respectively connected to the capacitor C 12 and the resistor R 16 and then connected to the nebulizer output terminal PWM-OUT, the resistor R 16 and the nebulizer output terminal PWM-OUT connection node and resistor A resistor R 18 is connected between R 17 and the line junction of the output terminal of the buck-boost circuit circuit VOUT, and the sixth pin OUT of the operational amplifier U4 is connected to the resistor R 19 and then connected to the current detection signal IDET and the capacitor C 13 and the capacitor respectively. The other end of C 13 is grounded. The first pin REF of the operational amplifier U 4 and the second pin GND are grounded. The third pin of the operational amplifier U 4 is connected to the resistor R 22 and then connected to the auxiliary boost VCC-12V. The junction between the third pin VCC and the resistor R 22 is respectively connected to the capacitor C 15 and the capacitor C 14 , and the other end of the capacitor C 15 and the capacitor C 14 is grounded; when the current passes through the resistor R 18 , the resistor R 18 is at both ends It will be divided, and then filtered by resistor R 16 , resistor R 17 and capacitor C 12 and then input to the operational amplifier U 4 . The operational amplifier U 4 amplifies the filtered voltage and filters it through resistor R 19 and capacitor C 13 . The resistance of the atomizer is calculated by the current detection signal IDET.
The anti-drying device for an electronic cigarette according to claim 1, wherein the buck-boost bridge circuit comprises a chip U 1 , a chip U 2 , MOS tubes Q 1 and Q 2 , MOS tubes Q 3 and Q 4 , a first Zener diode, a second Zener diode, a resistor R 1 , a resistor R 2 , a resistor R 3 , a capacitor C 1 , a capacitor C 3 , a capacitor C 2 , a capacitor C 4 , and an inductor L 1 , of the chip U 1 3 after a first ground pin VCC of capacitor C is connected, the third pin HO 1 U chip access gate MOS transistor Q 2, the tenth pin chip U LO access gate of the MOS. 1 Q 1 ', The first pin VCC of the chip U 2 is connected to the capacitor C 4 and grounded. The third pin HO of the chip U 2 is connected to the gate of the MOS transistor Q 3 , and the tenth pin LO of the chip U 2 is connected to the MOS transistor. Q gate electrode 4, the fourth pin the HS U chip 1 through the inductor L 1 of the chip access HS 2 U of the fourth pin, the second pin chip U 1 are connected a Zener diode D, a capacitor C , the other end of the capacitor C 1 chip access U HS 1 of the fourth pin, the other end of the Zener diode D 1 of the first U-chip access pin VCC 1, a chip U 2 are respectively connected to the second pin zener diode D 2, the capacitor C 2, the capacitance C 2 The outer end of the fourth pin access chips U HS 2, the other end of the Zener diode D 2 U access a first pin VCC 2 chip, the chip U 1 and U 2 each chip ninth pin VSS are grounded, The eighth pin IN of the chip U 1 is connected to the signal terminal PWM-UP of the boost output frequency of the microcontroller, and the eighth pin IN of the chip U 2 is connected to the signal terminal PWM-DN of the buck output frequency of the microcontroller. chip and the chip U 1 U 2 each are connected to the seventh pin EN-down control signal output terminal of the bridge PWM-EN, EN seventh pin chip U 2 and outputs the control signal PWM-EN-line terminal connected to the junction After the resistor R 3 is grounded, the sixth pin RDT of the chip U 1 is grounded after the resistor R 1 , and the sixth pin RDT of the chip U 2 is grounded after the resistor R 2 ; when the battery voltage is lower than the output voltage, the buck-boost The bridge circuit buck driver chip U 2 output signal turns on the MOS transistor Q 3 , connects the chip U 1 , the MOS transistors Q 1 and Q 2 through the inductor L 1 , and the boost driving chip U 1 is driven by the PWM output PWM-UP control signal of the microcontroller. MOS tube Q 1 and Q 2 boost output VOUT; conversely, when the battery voltage is higher than the output voltage, the buck-boost circuit boost drive chip U 1 output signal turns on MOS The tube Q 2 is connected to the chip U 2 and the MOS tubes Q 4 and Q 3 through the inductor L 1 , and the step-down driving chip U 2 drives the MOS transistor Q 4 and the Q 3 step-down output VOUT through the PWM output PWM-DN control signal.
A method for controlling an anti-drying device for an electronic cigarette according to any one of claims 1 to 7, comprising the steps of:

(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 causes the voltage rise and fall bridge circuit to output a voltage signal;

(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 buck-boost bridge circuit, and the electronic cigarette stops working.