Low-temperature baking non-combustible electronic cigarette heating device with constant temperature control function

Abstract

A low-temperature baking non-burning electronic cigarette heating device with a constant temperature control function includes an electronic cigarette heating element, and also has a bistable switch circuit, a heating and constant temperature circuit, and a conversion circuit. The heating wire of the electronic cigarette heating element also serves as a thermocouple. The bistable switch circuit, the heating and constant temperature circuit, and the conversion circuit are installed on the internal circuit board of the electronic cigarette body. The positive electrode of the lithium battery in the electronic cigarette body is connected to the bistable switch circuit, the conversion circuit, and the heating and constant temperature circuit through wires. The positive electrode of the heating wire of the heating element is made of nickel-chromium alloy, and the negative electrode is made of nickel-silicon alloy, and it can also be any other material that can be used as a thermocouple. In the present invention, the heating wire and the thermocouple are integrated into one, with small volume, compact structure, and low cost. Because the connection points on the heating wire substrate are reduced, the failure probability is also correspondingly reduced. When the heating wire works, it can also serve as a thermocouple to output signals at the pulse interval and enter the heating and constant temperature circuit, and the heating and constant temperature circuit will control the heating element to work at a constant temperature.

Description

Technical Field

[0001] The present invention relates to the field of electronic cigarette application devices, in particular to a low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function. Background Art

[0002] Low-temperature baking non-combustible electronic cigarettes are mainly used for smoking cessation and replacing cigarettes. They have the same appearance as cigarettes, a similar taste to cigarettes, and even many more flavors than ordinary cigarettes. They can also draw out smoke, taste, and sensations like cigarettes. Electronic cigarettes do not contain other harmful components such as tar and suspended particles in cigarettes, so they have relatively less impact on human health and are widely used.

[0003] As the main component of an electronic cigarette, the reliability of the heating element directly affects the use effect and service life of the electronic cigarette. To ensure the reliable operation of the heating element of the electronic cigarette, a thermocouple is installed at the heating element of the electronic cigarette. The thermocouple monitors the temperature of the heating element in real time and feeds the temperature signal back to the control circuit of the electronic cigarette. In existing electronic cigarettes, the thermocouple and the heating element belong to two different components. In actual application, since the thermocouple needs to be separately connected to the substrate of the heating element, it is not convenient for the miniaturization of the heating element, which will cause the overall external shape and volume of the electronic cigarette to become larger, making it inconvenient for users to carry; and due to the addition of connection points, the probability of failure is also increased accordingly. Summary of the Invention

[0004] In order to overcome various drawbacks of the heating element and thermocouple of existing electronic cigarettes due to structural limitations, the present invention provides a low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function, which integrates the heating element and the thermocouple. When the heating element works, it can not only play a heating role but also output a thermocouple signal to the signal input end of the heating and constant temperature circuit. Under the combined action of each circuit, the heating and constant temperature circuit can intermittently monitor the thermocouple signal of the heating element and can adjust the power input to the heating element in a timely manner according to the thermocouple signal of the heating element, so that the heating element works at a constant temperature, thereby achieving a compact structure, low cost, correspondingly reducing the probability of failure, and improving the service life of the heating element.

[0005] The technical solution adopted by the present invention to solve its technical problems is:

[0006] A low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function, including an electronic cigarette heating element, characterized by further comprising a bistable switch circuit, a heating constant temperature circuit, and a conversion circuit. The heating wire of the electronic cigarette heating element also serves as a thermocouple. The bistable switch circuit, the heating constant temperature circuit, and the conversion circuit are installed on the internal circuit board of the electronic cigarette. The positive electrode of the lithium battery in the electronic cigarette body is connected to the positive power input terminals of the bistable switch circuit and the conversion circuit through wires. The positive power output terminal of the conversion circuit is connected to the second positive power input terminal of the heating constant temperature circuit through wires. The power signal output terminal of the bistable switch circuit is connected to the power signal input terminal of the conversion circuit and the first power input terminal of the heating constant temperature circuit through wires. The reference voltage output terminal of the bistable switch circuit is connected to the signal input terminal of the heating constant temperature circuit through wires. The positive power output terminal of the heating constant temperature circuit is connected to the positive electrode of the electronic cigarette heating element through wires. The positive feedback signal input terminal of the heating constant temperature circuit is connected to the positive power input terminal of the electronic cigarette heating element through wires. The negative feedback signal input terminal of the heating constant temperature circuit is connected to the negative power input terminal of the electronic cigarette heating element through wires. The negative electrode of the lithium battery in the electronic cigarette body is connected to the negative power input terminals of the bistable switch circuit, the heating constant temperature circuit, the conversion circuit, and the electronic cigarette heating element through wires.

[0007] The positive electrode of the heating wire of the electronic cigarette heating element is made of nickel-chromium alloy, and the negative electrode is made of nickel-silicon alloy. It can also be any other material that can be used as a thermocouple.

[0008] The bistable switch circuit includes a resistor, a three-terminal voltage regulator module, a push-button switch, a field effect transistor, an NPN transistor, and a non-polar capacitor, which are connected by circuit board wiring. The model of the three-terminal voltage regulator module is XC6206P252M. One end of the first resistor is connected to the source electrode of the field effect transistor, and the other end of the first resistor is connected to one end of the second resistor, the gate electrode of the field effect transistor, and the collector electrode of the NPN transistor. The other end of the second resistor is connected to one end of the first non-polar capacitor and one end of the push-button switch. The other end of the push-button switch is connected to one end of the second non-polar capacitor, one end of the third resistor, one end of the fourth resistor, and the base electrode of the NPN transistor. The other end of the third resistor is connected to the drain electrode of the field effect transistor, the 3rd pin of the VIN port of the three-terminal voltage regulator module, and one end of the third non-polar capacitor. The 2nd pin of the VOUT port of the three-terminal voltage regulator module is connected to one end of the fourth non-polar capacitor. The other end of the first non-polar capacitor is connected to the other ends of the second non-polar capacitor, the third non-polar capacitor, the fourth non-polar capacitor, the other end of the fourth resistor, the emitter electrode of the NPN transistor, and the 2nd pin of the VSS port of the three-terminal voltage regulator module.

[0009] The heating and constant temperature circuit includes a variable resistor, resistors, diodes, non-polar capacitors, light-emitting diodes, NPN transistors, field effect transistors, and operational amplifier integrated circuits, which are connected by circuit board wiring. The model of the operational amplifier integrated circuit is LM358-SOP8. One end of the variable resistor is connected to one end of the third resistor, one end of the fourth resistor, and one end of the fifth resistor. The other end of the variable resistor is connected to one end of the first resistor. The other end of the first resistor is connected to one end of the fourteenth resistor, one end of the first non-polar capacitor, and pin 2 of the IN1- port of the operational amplifier integrated circuit. One end of the second resistor is connected to one end of the second non-polar capacitor and pin 3 of the IN+ port of the operational amplifier integrated circuit. The other end of the second resistor is connected to one end of the ninth resistor, the drain of the field effect transistor, and one end of the fifth non-polar capacitor. The negative pole of the diode is connected to pin 1 of the OUT1 port of the operational amplifier integrated circuit. The other end of the third resistor is connected to one end of the eighth resistor, one end of the seventh resistor, and pin 5 of the IN2+ port of the operational amplifier integrated circuit. The other end of the seventh resistor is connected to one end of the eleventh resistor and pin 7 of the OUT2 port of the operational amplifier integrated circuit. Pin 8 of the VCC port of the operational amplifier integrated circuit is connected to one end of the third non-polar capacitor. Pin 6 of the IN2- port of the operational amplifier integrated circuit is connected to one end of the fourth non-polar capacitor, the other end of the sixth resistor, the other end of the fourth resistor, and the other end of the fifth resistor. One end of the sixth resistor is connected to the positive pole of the diode. The other end of the ninth resistor is connected to the positive pole of the light-emitting diode. The other end of the eleventh resistor is connected to one end of the twelfth resistor and the base of the NPN transistor. The emitter of the NPN transistor is connected to one end of the thirteenth resistor. The collector of the NPN transistor is connected to the other end of the tenth resistor and the gate of the field effect transistor. The other end of the fourteenth resistor is connected to the other end of the first non-polar capacitor, the other end of the second non-polar capacitor, the other end of the third non-polar capacitor, the other end of the eighth resistor, the other end of the fourth non-polar capacitor, the other end of the twelfth resistor, the other end of the thirteenth resistor, the other end of the fifth non-polar capacitor, the negative pole of the light-emitting diode, and pin 4 of the GND port of the operational amplifier integrated circuit.

[0010] The conversion circuit includes a DC-DC boost module, non-polar capacitors, an inductor, a diode, and resistors, which are connected through circuit board wiring. The model of the DC-DC boost module is HM9229. One end of the first non-polar capacitor, one end of the second non-polar capacitor, one end of the third non-polar capacitor, and one end of the inductor are connected. The other end of the inductor is connected to one end of the first resistor, the positive pole of the diode, the LX ports 1 and 2 of the DC-DC boost module. The other end of the first resistor is connected to one end of the fourth non-polar capacitor. One end of the fifth non-polar capacitor is connected to the VCC port 3 of the DC-DC boost module. One end of the second resistor is connected to the EN port 4 of the DC-DC boost module. The negative pole of the diode is connected to one end of the third resistor, one end of the fourth resistor, one end of the sixth non-polar capacitor, one end of the seventh non-polar capacitor, and one end of the eighth non-polar capacitor. The HVDD port 8 of the DC-DC boost module is connected to the other end of the third resistor and one end of the ninth non-polar capacitor. The OC port 7 of the DC-DC boost module is connected to one end of the fifth resistor. The COMP port 6 of the DC-DC boost module is connected to one end of the sixth resistor and one end of the eleventh non-polar capacitor. The other end of the sixth resistor is connected to the other end of the tenth non-polar capacitor. The other end of the fourth resistor is connected to one end of the seventh resistor and the FB port 5 of the DC-DC boost module. The other end of the ninth non-polar capacitor is connected to the other end of the fifth resistor, one end of the tenth non-polar capacitor, the other end of the eleventh non-polar capacitor, the other end of the first non-polar capacitor, the other end of the second non-polar capacitor, the other end of the third non-polar capacitor, the other end of the fourth non-polar capacitor, the other end of the fifth non-polar capacitor, the other end of the sixth non-polar capacitor, the other end of the seventh non-polar capacitor, the other end of the eighth non-polar capacitor, and the GND port 9 of the DC-DC boost module.

[0011] The beneficial effects of the present invention are as follows: In the present invention, the heating wire and the thermocouple of the heating element are integrated. The series connection of the heating wire and the thermocouple reduces the volume, makes the structure compact, and has a low cost (no need to use a thermocouple separately). Since the number of connection points on the heating wire substrate is reduced, the failure probability is also correspondingly reduced. When working, after the user presses the key switch of the bistable switch circuit, then, under the action of its internal circuit, the bistable switch circuit outputs a 2.5V 100mA power supply into the heating and constant temperature circuit as the reference voltage of the heating and constant temperature circuit. At the same time, under the action of its internal circuit, the conversion circuit outputs a 4.2V 6A power supply into the heating and constant temperature circuit as the working power supply of the heating wire of the heating element. When the heating element works, it will output a signal into the heating and constant temperature circuit as a thermocouple. When the temperature of the heating element is too high and the voltage signal input to the heating and constant temperature circuit is too high, the heating and constant temperature circuit will control the heating element to lose power and stop heating. When the temperature of the heating element is too low and the voltage signal input to the heating and constant temperature circuit is too low, the heating and constant temperature circuit will control the heating element to get power and heat, so that the heating element gets power and works again. Through the above, it can ensure that the heating element works at a constant temperature of about 350°C. Based on the above, the present invention has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described below in conjunction with the drawings and embodiments.

[0013] Figure 1 It is the structural circuit diagram of the present invention.

[0014] Figure 2 It is the schematic diagram of the structure of the heating wire of the spiral electronic cigarette heating element of the present invention.

[0015] Figure 3 It is the schematic diagram of the structure between the heating wire and the outer shell of the spiral electronic cigarette heating element of the present invention.

[0016] Figure 4 It is the schematic diagram of the structure between the heating wire and the outer shell of the flat electronic cigarette heating element of the present invention.

[0017] Figure 5 It is the circuit diagram of the bistable switch circuit of the present invention.

[0018] Figure 6 It is the circuit diagram of the heating and constant temperature circuit of the present invention.

[0019] Figure 7 It is the circuit diagram of the conversion circuit of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Figure 1As shown in the figure, a low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function includes an electronic cigarette heating element, and also has a bistable switch circuit Q4, Q5, a heating and constant temperature circuit U1, and a conversion circuit U2. The heating wire RT of the electronic cigarette heating element also serves as a thermocouple. The bistable switch circuit Q4, Q5, the heating and constant temperature circuit U1, and the conversion circuit U2 are installed on the internal circuit board of the electronic cigarette. The positive electrode of the lithium battery G in the electronic cigarette body is connected to the positive power input terminals of the bistable switch circuit Q4, Q5 and the conversion circuit U2 through wires. The positive power output terminal of the conversion circuit U2 is connected to the second positive power input terminal of the heating and constant temperature circuit U1 through a wire. The power signal output terminals of the bistable switch circuit Q4, Q5 are connected to the power signal input terminal of the conversion circuit U2 and the first power input terminal of the heating and constant temperature circuit U1 through wires. The reference voltage output terminal of the bistable switch circuit Q4, Q5 is connected to the signal input terminal of the heating and constant temperature circuit U1 through a wire. The positive power output terminal of the heating and constant temperature circuit U1 is connected to the positive electrode of the heating wire RT of the electronic cigarette heating element through a wire. The positive feedback signal input terminal of the heating and constant temperature circuit U1 is connected to the positive power input terminal of the heating wire RT of the electronic cigarette heating element through a wire. The negative feedback signal input terminal of the heating and constant temperature circuit U1 is connected to the negative power input terminal of the heating wire RT of the electronic cigarette heating element through a wire. The negative electrode of the lithium battery G in the electronic cigarette body is connected to the negative power input terminals of the bistable switch circuit Q4, Q5, the heating and constant temperature circuit U1, the conversion circuit U2, and the heating wire RT of the electronic cigarette heating element through wires. Figure 2 As shown in the figure, the positive electrode 1-1 of the heating wire of the electronic cigarette heating element 1 is made of nickel-chromium alloy, and the negative electrode 1-2 is made of nickel-silicon alloy. It can also be any other material that can be used as a thermocouple. 2 is the substrate of the heating wire 1 of the electronic cigarette heating element, and 4 is the temperature measurement point of the electronic cigarette heating element 1, which is located at the connection point of the positive and negative electrodes. Figure 3 As shown in the figure, 1 is the heating wire of the electronic cigarette heating element, and 3 is the outer shell of the electronic cigarette heating element, which is made of ceramic material or metal material. A ceramic tube is sleeved inside the metal outer shell for insulation. The heating wire 1 is sleeved inside the outer shell 3 and encapsulated with ceramic glue. 4 is the temperature measurement point of the electronic cigarette heating element, which is located at the connection point of the positive and negative electrodes. Figure 4 As shown in the figure, 5 is the heating wire of the electronic cigarette heating element, and 7 is the sheet-shaped outer shell of the electronic cigarette heating element, which is made of ceramic material or metal material. A mica sheet is sleeved inside the metal outer shell for insulation. 6 is the temperature measurement point of the electronic cigarette heating element, which is located at the connection point of the positive and negative electrodes.

[0021] Figure 5As shown in the figure, the bistable switch circuit includes resistors R5, R9, R11, R16, push-button switch SW1, field-effect transistor Q5, NPN transistor Q4, non-polar capacitors C15, C16, which are connected by circuit board wiring; the three-terminal voltage regulator module U3 is of model XC6206P252M. One end of the first resistor R5 is connected to the source of the field-effect transistor Q5, and the other end of the first resistor R5 is connected to one end of the second resistor R9, the gate of the field-effect transistor Q5, and the collector of the NPN transistor Q4. The other end of the second resistor R9 is connected to one end of the first non-polar capacitor C15 and one end of the push-button switch SW1. The other end of the push-button switch SW1 is connected to one end of the second non-polar capacitor C16, one end of the third resistor R11, one end of the fourth resistor R16, and the base of the NPN transistor Q4. The other end of the third resistor R11 is connected to the drain of the field-effect transistor Q5, the VIN port 3 pin of the three-terminal voltage regulator module U3, and one end of the third non-polar capacitor C6. The VOUT port 2 pin of the three-terminal voltage regulator module U3 is connected to one end of the fourth non-polar capacitor C14. The other end of the first non-polar capacitor C15 is connected to the other end of the second non-polar capacitor C16, the other end of the third non-polar capacitor C6, the other end of the fourth non-polar capacitor C14, the other end of the fourth resistor R16, the emitter of the NPN transistor Q4, and the VSS port 2 pin of the three-terminal voltage regulator module U3. The operation button of the push-button switch SW1 is located outside the housing of the electronic cigarette body, facilitating the operation of the user.

[0022] Figure 6As shown in the figure, the heating and constant temperature circuit includes a variable resistor VR2, resistors TR, R15, R13, R12, R22, R6, R21, R8, R4, R10, R20, R18, R17, R19, a diode D1, non-polar capacitors C3, C9, C1, C2, C5, a light-emitting diode LED3, an NPN transistor Q1, a field-effect transistor Q2, and an operational amplifier integrated circuit U1, which are connected by circuit board wiring. The model of the operational amplifier integrated circuit U1 is LM358-SOP8. One end of the variable resistor VR2 is connected to one end of the third resistor R12, one end of the fourth resistor R22, and one end of the fifth resistor R6. The other end of the variable resistor VR2 is connected to one end of the first resistor TR. The other end of the first resistor TR is connected to one end of the fourteenth resistor R13, one end of the first non-polar capacitor C3, and the IN1- port 2 pin of the operational amplifier integrated circuit U1. One end of the second resistor R15 is connected to one end of the second non-polar capacitor C9 and the IN+ port 3 pin of the operational amplifier integrated circuit U1. The other end of the second resistor R15 is connected to one end of the ninth resistor R10, the drain of the field-effect transistor Q2, and one end of the fifth non-polar capacitor C5. The negative pole of the diode D1 is connected to the OUT1 port 1 pin of the operational amplifier integrated circuit U1. The other end of the third resistor R12 is connected to one end of the eighth resistor R4, one end of the seventh resistor R8, and the IN2+ port 5 pin of the operational amplifier integrated circuit U1. The other end of the seventh resistor R8 is connected to one end of the eleventh resistor R17 and the OUT2 port 7 pin of the operational amplifier integrated circuit U1. The VCC port 8 pin of the operational amplifier integrated circuit U1 is connected to one end of the third non-polar capacitor C1. The IN2- port 6 pin of the operational amplifier integrated circuit U1 is connected to one end of the fourth non-polar capacitor C2, the other end of the sixth resistor R21, the other end of the fourth resistor R22, and the other end of the fifth resistor R6. One end of the sixth resistor R21 is connected to the positive pole of the diode D1. The other end of the ninth resistor R10 is connected to the positive pole of the light-emitting diode LED3. The other end of the eleventh resistor R17 is connected to one end of the twelfth resistor R18 and the base of the NPN transistor Q1. The emitter of the NPN transistor Q1 is connected to one end of the thirteenth resistor R10. The collector of the NPN transistor Q1 is connected to the other end of the tenth resistor R20 and the gate of the field-effect transistor Q2. The other end of the fourteenth resistor R13 is connected to the other end of the first non-polar capacitor C3, the other end of the second non-polar capacitor C9, the other end of the third non-polar capacitor C1, the other end of the eighth resistor R4, the other end of the fourth non-polar capacitor C2, the other end of the twelfth resistor R18, the other end of the thirteenth resistor R19, the other end of the fifth non-polar capacitor C5, the negative pole of the light-emitting diode LED3, and the GND port 4 pin of the operational amplifier integrated circuit U1.

[0023] Figure 7As shown in the figure, the conversion circuit includes a DC-DC boost module U2, non-polar capacitors C24, C23, C7, C21, C22, C31, C11, C12, C26, C28, C30, an inductor L1, a diode D2, and resistors R23, R1, R24, R35, R25, R26, R39, which are connected by circuit board wiring. The model of the DC-DC boost module U2 is HM9229. One end of the first non-polar capacitor C24, one end of the second non-polar capacitor C23, one end of the third non-polar capacitor C7, and one end of the inductor L1 are connected. The other end of the inductor L1 is connected to one end of the first resistor R23, the positive electrode of the diode D2, the LX ports 1 and 2 of the DC-DC boost module U2. The other end of the first resistor R23 is connected to one end of the fourth non-polar capacitor C21. One end of the fifth non-polar capacitor C22 is connected to the VCC port 3 of the DC-DC boost module U2. One end of the second resistor R1 is connected to the EN port 4 of the DC-DC boost module U2. The negative electrode of the diode D2 is connected to one end of the third resistor R24, one end of the fourth resistor R35, one end of the sixth non-polar capacitor C31, one end of the seventh non-polar capacitor C11, and one end of the eighth non-polar capacitor C12. The HVDD port 8 of the DC-DC boost module U2 is connected to the other end of the third resistor R24 and one end of the ninth non-polar capacitor C26. The OC port 7 of the DC-DC boost module U2 is connected to one end of the fifth resistor R25. The COMP port 6 of the DC-DC boost module U2 is connected to one end of the sixth resistor R26 and one end of the eleventh non-polar capacitor C30. The other end of the sixth resistor R26 is connected to the other end of the tenth non-polar capacitor C28. The other end of the fourth resistor R35 is connected to one end of the seventh resistor R39 and the FB port 5 of the DC-DC boost module U2. The other end of the ninth non-polar capacitor C26 is connected to the other end of the fifth resistor R25, one end of the tenth non-polar capacitor C28, the other end of the eleventh non-polar capacitor C30, the other end of the first non-polar capacitor C24, the other end of the second non-polar capacitor C23, the other end of the third non-polar capacitor C7, the other end of the fourth non-polar capacitor C21, the other end of the fifth non-polar capacitor C22, the other end of the sixth non-polar capacitor C31, the other end of the seventh non-polar capacitor C11, the other end of the eighth non-polar capacitor C12, and the GND port 9 of the DC-DC boost module U2.

[0024] Figure 5 , 6As shown in FIGS. 7, one end of the positive electrode of the lithium battery G in the electronic cigarette body, one end of the resistor R5 at the positive power input terminal of the bistable switch circuit, and one end of the inductor L1 at the positive power input terminal of the conversion circuit are connected by a wire. One end of the non-polar capacitor C12 at the positive power output terminal of the conversion circuit and the source electrode of the field effect transistor Q2 at the second positive power input terminal of the heating and constant temperature circuit are connected by a wire. One end of the resistor R11 at the power signal output terminal of the bistable switch circuit, the other end of the resistor R1 at the power signal input terminal of the conversion circuit, and one end of the non-polar capacitor C1 at the first power input terminal of the heating and constant temperature circuit are connected. One end of the non-polar capacitor C14 at the reference voltage output terminal of the bistable switch circuit and one end of the adjustable resistor VR2 at the signal input terminal of the heating and constant temperature circuit are connected by a wire. The drain electrode of the field effect transistor Q2 at the positive power output terminal of the heating and constant temperature circuit and the positive electrode of the heating wire RT of the electronic cigarette heating element are connected by a wire. The other end of the resistor R15 at the positive feedback signal input terminal of the heating and constant temperature circuit and the positive power input terminal of the heating wire RT of the electronic cigarette heating element are connected by a wire. The other end of the non-polar capacitor C3 at the negative feedback signal input terminal of the heating and constant temperature circuit and the negative power input terminal of the heating wire RT of the electronic cigarette heating element are connected by a wire. The negative electrode of the lithium battery G in the electronic cigarette body, the other end of the resistor R16 at the negative power input terminal of the bistable switch circuit, the other end of the resistor R18 at the negative power input terminal of the heating and constant temperature circuit, the other end of the resistor R39 at the negative power input terminal of the conversion circuit, and the negative power input terminal of the heating wire RT of the electronic cigarette heating element are connected by a wire.

[0025] Figure 5 , 6As shown in FIGS. 7, in actual use, the power supply (3.2 - 4.2V) output by the lithium battery G inside the e-cigarette body enters the positive power input terminal of the bistable switch circuit and the positive power input terminal of the conversion circuit. Then, the bistable switch circuit and the conversion circuit are in the standby state (the negative power input terminals of the bistable switch circuit and the conversion circuit are connected to the negative pole of the lithium battery G), and the heating wire RT of the e-cigarette heating element is in the power-off state. When the user needs to use the e-cigarette, after pressing the key switch SW1 of the bistable switch circuit, the positive power supply output by the lithium battery G will enter the base of the NPN transistor Q4 after being stepped down by the resistors R5 and R9. The NPN transistor Q4 is in the conducting state under the combined action of its peripheral components, namely the non-polar capacitors C15 and C16, and the resistors R16 and R11. Thus, the NPN transistor Q4 outputs a low level at its collector. Since the collector of the NPN transistor Q4 is connected to the gate of the field-effect transistor Q5, at this time, the field-effect transistor Q5 is reversely biased and conducts, and its drain outputs a power supply of about 4V and enters the VIN port 3 of the three-terminal voltage regulator module U3. Then, under the combined action of its internal circuit and the peripheral components, namely the non-polar capacitors C6 and C14, the VOUT port 2 of the three-terminal voltage regulator module U3 outputs a stable 2.5V 100mA power supply and enters one end of the adjustable resistor VR2 of the heating and constant-temperature circuit, and then enters the IN1- port 2 of the operational amplifier integrated circuit U1 through the adjustable resistor VR2 and the resistor TR as the reference voltage of the operational amplifier integrated circuit U1. After the power supply output by the lithium battery G enters the conversion circuit, the DC-DC boost module U2 is in the standby state under the combined action of its internal circuit and the peripheral components, namely the resistor R23, and the non-polar capacitors C23, C7, C21, C24, C22, and the inductor L1 (which plays a filtering role). When the drain of the field-effect transistor Q5 of the bistable switch circuit outputs a power supply of about 4V, the power supply will enter the EN port 4 of the DC-DC boost module U2 after being stepped down and current-limited by the resistor R1. The DC-DC boost module U2 is under the combined action of its internal circuit and the peripheral components, namely the resistors R24, R25, R26, R35, R39, and the non-polar capacitors C26, C28, C30, C31, C11, C12. The DC-DC boost module U2 outputs a 4.2V 6A power supply at its pins 1 and 2. The power supply enters the source of the field-effect transistor Q2 and the other end of the resistor R20 of the heating and constant-temperature circuit through the one-way conduction of the diode D2 (the source of the field-effect transistor Q2 is connected to the other end of the resistor R20), providing the second positive power supply (the working power supply of the heating wire RT) for the heating and constant-temperature circuit.In the heating and constant temperature circuit, after the field effect transistor Q5 of the bistable switch circuit outputs a power supply of about 4V at the drain, the power supply of about 4V will enter the 8th pin of the VCC port, which is the first power input terminal of the operational amplifier integrated circuit U1 in the heating and constant temperature circuit. Then, the operational amplifier integrated circuit U1 is in the powered-on working state. The 5th, 6th, and 7th pins of the operational amplifier integrated circuit U1 and the peripheral components resistor R12, R4, R22, R6, R21, R8, as well as the non-polar capacitors C1, C2, and diode D1 form a monostable circuit. The monostable circuit is in a stable state. The high potential output from the 7th pin of the operational amplifier integrated circuit U1 is stepped down and current-limited by the resistor R17 and enters the base of the NPN transistor Q1. The NPN transistor Q1 conducts under the combined action of the peripheral components resistors R18, R19, and R20, and the low level output from the collector enters the gate G of the field effect transistor Q2. Then, the field effect transistor Q2 conducts and its drain outputs a high level to enter the positive power input terminal of the heating wire RT of the electronic cigarette heating element. Since the negative power input terminal of the heating wire RT of the electronic cigarette heating element is connected to the negative pole of the lithium battery G, the heating wire RT of the electronic cigarette heating element will be powered on and generate heat at this moment. During operation, the heating wire RT of the electronic cigarette heating element also serves as a thermocouple and outputs a voltage signal, which is stepped down and current-limited by the resistor R15 and input to the 3rd pin of the IN1+ port of the operational amplifier integrated circuit U1 (the non-polar capacitors C9, C3, and resistor R13 are the peripheral components of the operational amplifier integrated circuit U1). Under the action of its internal circuit, the operational amplifier integrated circuit U1 compares the voltage signal output by the heating wire RT of the electronic cigarette heating element as a thermocouple with the reference voltage that enters the 2nd pin of the IN1- port of the operational amplifier integrated circuit U1 through the adjustable resistor VR2 and resistor TR from the 2nd pin of the three-terminal voltage regulator module U3. When the heating temperature of the heating wire RT of the electronic cigarette heating element is high (higher than 350°C), that is, when the voltage signal output by the heating wire RT of the electronic cigarette heating element as a thermocouple is higher than the voltage at the 2nd pin of the IN1- port of the operational amplifier integrated circuit U1, the monostable circuit flips and is no longer in a stable state. The 7th pin of the operational amplifier integrated circuit U1 no longer outputs a high level. Furthermore, the NPN transistor Q1 and the field effect transistor Q2 are cut off, and the drain of the field effect transistor Q2 no longer outputs a high level to enter the positive power input terminal of the heating wire RT. The heating wire RT of the electronic cigarette heating element no longer generates heat. When the heating temperature of the heating wire RT of the electronic cigarette heating element is low (lower than 350°C), that is, when the voltage signal output by the heating wire RT of the electronic cigarette heating element as a thermocouple is lower than the voltage at the 2nd pin of the IN1- port of the operational amplifier integrated circuit U1, the monostable circuit is in a stable state again. The 7th pin of the operational amplifier integrated circuit U1 outputs a high level again. Furthermore, the NPN transistor Q1 and the field effect transistor Q2 conduct, and the drain of the field effect transistor Q2 outputs a high level to enter the positive power input terminal of the heating wire RT. The heating wire RT of the electronic cigarette heating element is powered on and generates heat again. The above process continuously cycles to keep the heating wire RT in a constant working state of 350°C all the time. After the user finishes using, just turn off the key switch SW1.When the heating wire RT is working, the light-emitting diode LED3 obtains power through the resistor R10 and lights up to prompt the user that the heating wire RT of the e-cigarette heating element is in the working state. The models of all components of the present invention are marked in the circuit diagram and will not be elaborated here. The resistance value of the heating wire RT of the heating element of this application is 0.5 to 1 ohm.

[0026] The foregoing has shown and described the basic principles, main features and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0027] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function, comprising an electronic cigarette heating element, characterized in that It also has a bistable switch circuit, a heating and constant temperature circuit, and a conversion circuit. The heating wire of the e-cigarette heating element also serves as a thermocouple. The bistable switch circuit, the heating and constant temperature circuit, and the conversion circuit are installed on the internal circuit board of the e-cigarette. The positive electrode of the lithium battery in the e-cigarette body is connected to the positive power input terminals of the bistable switch circuit and the conversion circuit through wires. The positive power output terminal of the conversion circuit is connected to the second positive power input terminal of the heating and constant temperature circuit through wires. The power signal output terminal of the bistable switch circuit is connected to the power signal input terminal of the conversion circuit and the first power input terminal of the heating and constant temperature circuit through wires. The reference voltage output terminal of the bistable switch circuit is connected to the signal input terminal of the heating and constant temperature circuit through wires. The positive power output terminal of the heating and constant temperature circuit is connected to the positive electrode of the e-cigarette heating element through wires. The positive feedback signal input terminal of the heating and constant temperature circuit is connected to the positive power input terminal of the e-cigarette heating element through wires. The negative feedback signal input terminal of the heating and constant temperature circuit is connected to the negative power input terminal of the e-cigarette heating element through wires. The negative electrode of the lithium battery in the e-cigarette body is connected to the negative power input terminals of the bistable switch circuit, the heating and constant temperature circuit, the conversion circuit, and the e-cigarette heating element through wires.

2. The low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function according to claim 1, characterized in that The positive electrode of the heating wire of the e-cigarette heating element is made of nickel-chromium alloy, and the negative electrode is made of nickel-silicon alloy, and it can also be any other material that can be used as a thermocouple.

3. The low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function according to claim 1, characterized in that The bistable switch circuit includes resistors, a three-terminal voltage regulator module, a push-button switch, a field effect transistor, an NPN transistor, and non-polar capacitors, which are connected by circuit board wiring. The model of the three-terminal voltage regulator module is XC6206P252M. One end of the first resistor is connected to the source electrode of the field effect transistor, and the other end of the first resistor is connected to one end of the second resistor, the gate electrode of the field effect transistor, and the collector electrode of the NPN transistor. The other end of the second resistor is connected to one end of the first non-polar capacitor and one end of the push-button switch. The other end of the push-button switch is connected to one end of the second non-polar capacitor, one end of the third resistor, one end of the fourth resistor, and the base electrode of the NPN transistor. The other end of the third resistor is connected to the drain electrode of the field effect transistor, the 3rd pin of the VIN port of the three-terminal voltage regulator module, and one end of the third non-polar capacitor. The 2nd pin of the VOUT port of the three-terminal voltage regulator module is connected to one end of the fourth non-polar capacitor. The other end of the first non-polar capacitor is connected to the other ends of the second non-polar capacitor, the third non-polar capacitor, the fourth non-polar capacitor, the other end of the fourth resistor, the emitter electrode of the NPN transistor, and the 2nd pin of the VSS port of the three-terminal voltage regulator module.

4. The low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function according to claim 1, characterized in that The heating and constant temperature circuit includes a variable resistor, resistors, diodes, non-polar capacitors, light-emitting diodes, NPN transistors, field-effect transistors, and operational amplifier integrated circuits, which are connected by circuit board wiring. The model of the operational amplifier integrated circuit is LM358-SOP8. One end of the variable resistor is connected to one end of the third resistor, one end of the fourth resistor, and one end of the fifth resistor. The other end of the variable resistor is connected to one end of the first resistor. The other end of the first resistor is connected to one end of the fourteenth resistor, one end of the first non-polar capacitor, and pin 2 of the IN1- port of the operational amplifier integrated circuit. One end of the second resistor is connected to one end of the second non-polar capacitor and pin 3 of the IN+ port of the operational amplifier integrated circuit. The other end of the second resistor is connected to one end of the ninth resistor, the drain of the field-effect transistor, and one end of the fifth non-polar capacitor. The negative pole of the diode is connected to pin 1 of the OUT1 port of the operational amplifier integrated circuit. The other end of the third resistor is connected to one end of the eighth resistor, one end of the seventh resistor, and pin 5 of the IN2+ port of the operational amplifier integrated circuit. The other end of the seventh resistor is connected to one end of the eleventh resistor and pin 7 of the OUT2 port of the operational amplifier integrated circuit. Pin 8 of the VCC port of the operational amplifier integrated circuit is connected to one end of the third non-polar capacitor. Pin 6 of the IN2- port of the operational amplifier integrated circuit is connected to one end of the fourth non-polar capacitor, the other end of the sixth resistor, the other end of the fourth resistor, and the other end of the fifth resistor. One end of the sixth resistor is connected to the positive pole of the diode. The other end of the ninth resistor is connected to the positive pole of the light-emitting diode. The other end of the eleventh resistor is connected to one end of the twelfth resistor and the base of the NPN transistor. The emitter of the NPN transistor is connected to one end of the thirteenth resistor. The collector of the NPN transistor is connected to the other end of the tenth resistor and the gate of the field-effect transistor. The other end of the fourteenth resistor is connected to the other end of the first non-polar capacitor, the other end of the second non-polar capacitor, the other end of the third non-polar capacitor, the other end of the eighth resistor, the other end of the fourth non-polar capacitor, the other end of the twelfth resistor, the other end of the thirteenth resistor, the other end of the fifth non-polar capacitor, the negative pole of the light-emitting diode, and pin 4 of the GND port of the operational amplifier integrated circuit.

5. The low-temperature baking non-combustible electronic cigarette heating device with a constant temperature control function according to claim 1, characterized in that The conversion circuit includes a DC-DC boost module, non-polar capacitors, an inductor, a diode, and resistors, which are connected by circuit board wiring. The model of the DC-DC boost module is HM9229. One end of the first non-polar capacitor is connected to one end of the second non-polar capacitor, one end of the third non-polar capacitor, and one end of the inductor. The other end of the inductor is connected to one end of the first resistor, the positive pole of the diode, and the LX ports 1 and 2 of the DC-DC boost module. The other end of the first resistor is connected to one end of the fourth non-polar capacitor. One end of the fifth non-polar capacitor is connected to the VCC port 3 of the DC-DC boost module. One end of the second resistor is connected to the EN port 4 of the DC-DC boost module. The negative pole of the diode is connected to one end of the third resistor, one end of the fourth resistor, one end of the sixth non-polar capacitor, one end of the seventh non-polar capacitor, and one end of the eighth non-polar capacitor. The HVDD port 8 of the DC-DC boost module is connected to the other end of the third resistor and one end of the ninth non-polar capacitor. The OC port 7 of the DC-DC boost module is connected to one end of the fifth resistor. The COMP port 6 of the DC-DC boost module is connected to one end of the sixth resistor and one end of the eleventh non-polar capacitor. The other end of the sixth resistor is connected to the other end of the tenth non-polar capacitor. The other end of the fourth resistor is connected to one end of the seventh resistor and the FB port 5 of the DC-DC boost module. The other end of the ninth non-polar capacitor is connected to the other end of the fifth resistor, one end of the tenth non-polar capacitor, the other end of the eleventh non-polar capacitor, the other end of the first non-polar capacitor, the other end of the second non-polar capacitor, the other end of the third non-polar capacitor, the other end of the fourth non-polar capacitor, the other end of the fifth non-polar capacitor, the other end of the sixth non-polar capacitor, the other end of the seventh non-polar capacitor, the other end of the eighth non-polar capacitor, and the GND port 9 of the DC-DC boost module.

Images