A heating wire heating power control circuit, method and electronic cigarette

Abstract

The application discloses a heating wire heating power control circuit, method and electronic cigarette. The circuit is connected with the heating wire and comprises a power supply module, a current detection wire or a current detection resistor, a first heating wire wire, a second heating wire wire and a control module. The power supply module is connected with a battery voltage and a control end of the control module and one end of the current detection wire or the current detection resistor. One end of the current detection wire or the current detection resistor is also connected with a first detection end of the control module, and the other end is respectively connected with a second detection end of the control module and one end of the first heating wire wire. The other end of the first heating wire is connected with one end of the heating wire. One end of the second heating wire wire is connected with the other end of the heating wire, and the other end is grounded. The control module is used for controlling the power supply module to supply power to the heating wire and is also used for collecting the voltage between the current detection wire or the current detection resistor to control the heating power of the heating wire. The application can realize constant power control of the heating wire.

Description

Technical Field

[0001] This invention relates to the field of electronic equipment technology, and in particular to a heating wire heating power control circuit, method, and electronic cigarette. Background Technology

[0002] For electronic cigarettes currently on the market, achieving constant power control and anti-dry-burning functions requires measuring the resistance of the heating wire. There are generally two methods for measuring the heating wire resistance: 1. Injecting a fixed current into the heating wire using a constant current source, then using an analog-to-digital converter (ADC) to detect the voltage across the heating wire and calculate the resistance using the formula R = U / I; 2. Adding a PMOS transistor with a resistor (e.g., 20 ohms) connected in series at its source (S) terminal, and connecting the other end of the resistor to the heating wire. For the first solution, adding a constant current source increases circuit cost. For the second solution, the on-resistance of the PMOS transistor affects the heating wire power calculation. Furthermore, the heating wire needs to be connected to the control board via wires; the internal resistance of these wires causes a voltage drop across the heating wire, which also affects the power calculation.

[0003] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a heating wire heating power control circuit, method and electronic cigarette to solve the problem that when the existing scheme of measuring the resistance of the heating wire uses a resistor connected in series on a PMOS, the on-resistance of the PMOS and the wires between the heating wire and the control board will affect the power calculation of the heating wire.

[0005] The technical solution of the present invention is as follows:

[0006] A heating wire heating power control circuit, connected to a heating wire, is used to control the heating power of the heating wire, comprising: a power supply module, a current detection wire or a current detection resistor, a first heating wire wire, a second heating wire wire, and a control module;

[0007] The power supply module is connected to the battery voltage and is connected to the control terminal of the control module and one end of the current detection wire or current detection resistor, respectively.

[0008] One end of the current sensing wire or current sensing resistor is also connected to the first sensing terminal of the control module, and the other end of the current sensing wire or current sensing resistor is connected to the second sensing terminal of the control module and one end of the first heating wire wire, respectively.

[0009] The other end of the first heating wire is connected to one end of the heating wire;

[0010] One end of the second heating wire is connected to the other end of the heating wire, and the other end of the second heating wire is grounded;

[0011] The control module is used to control the power supply module to supply power to the heating wire; the control module is also used to collect the voltage across the current detection wire or the current detection resistor and control the heating power of the heating wire according to the voltage across the current detection wire or the current detection resistor.

[0012] In a further embodiment of the present invention, the material of the current detection wire is the same as that of the first heating wire.

[0013] In a further embodiment of the present invention, the power supply module includes: a MOSFET, a first resistor, and a second resistor; wherein,

[0014] The drain of the MOS transistor is connected to the battery voltage and is connected to one end of the first resistor;

[0015] The gate of the MOS transistor is connected to the other end of the first resistor and one end of the second resistor, respectively.

[0016] The source of the MOS transistor is connected to one end of the current sensing wire or the current sensing resistor and the first detection terminal of the control module, respectively.

[0017] The other end of the second resistor is connected to the control terminal of the control module.

[0018] In a further embodiment of the present invention, the control module is a micro control unit.

[0019] The present invention also provides an electronic cigarette, including the heating power control circuit of the heating wire described above, and further including: a battery module, a charging management module, and a charging interface; wherein,

[0020] The battery module is connected to the charging management module, the power supply module, and the control module respectively, and the battery module is used to supply power to the power supply module and the control module.

[0021] The charging management module is connected to both the control module and the charging interface, and the charging management module is used to charge the battery module through the charging interface.

[0022] In a further embodiment of the present invention, the electronic cigarette further includes: a first light-emitting diode; the first light-emitting diode is connected to the control module, and the first light-emitting diode is used to display the charging status of the electronic cigarette or the working status of the electronic cigarette.

[0023] The present invention also provides a heating wire heating power control method applied to the heating wire heating power control circuit described above, comprising:

[0024] The control module controls the power supply module to supply power to the heating wire;

[0025] The control module detects the voltage across the current sensing wire or the current sensing resistor, and calculates the current flowing through the loop based on the voltage across the current sensing wire or the resistance of the current sensing wire or the current sensing resistor.

[0026] The control module calculates the voltage drop of the first heating wire and the second heating wire based on the current flowing through the circuit, the resistance of the first heating wire, and the resistance of the second heating wire.

[0027] The voltage drop across the heating wire is obtained by comparing the voltage across the current sensing wire or the current sensing resistor with the voltage drop across the first heating wire and the second heating wire.

[0028] The control module obtains the resistance of the heating wire based on the voltage drop across the heating wire and the current flowing through the circuit.

[0029] The heating power of the heating wire is adjusted by regulating the voltage drop across its two ends.

[0030] A further provision of the present invention includes the step of adjusting the heating power of the heating wire by adjusting the voltage drop across the heating wire, comprising:

[0031] The control module acquires the battery voltage when the heating wire is in heating mode.

[0032] The control module uses pulse width modulation to adjust the voltage across the heating wire, thereby regulating the heating power of the heating wire. The control module obtains the duty cycle of the pulse width modulation signal based on the battery voltage and the resistance of the heating wire.

[0033] In a further embodiment of the present invention, before the step of the control module controlling the power supply module to supply power to the heating wire, the following is also included:

[0034] The resistance of the current sensing wire is measured;

[0035] The resistance values ​​of the first heating wire and the second heating wire are obtained by using a proportional method and based on the resistance value of the measuring wire.

[0036] This invention provides a heating wire heating power control circuit, method, and electronic cigarette. The heating wire heating power control circuit is connected to a heating wire and includes: a power supply module, a current detection wire or a current detection resistor, a first heating wire, a second heating wire, and a control module. The power supply module is connected to a battery voltage and is connected to the control terminal of the control module and one end of the current detection wire or current detection resistor. One end of the current detection wire or current detection resistor is also connected to a first detection terminal of the control module, and the other end of the current detection wire or current detection resistor is connected to a second detection terminal of the control module and one end of the first heating wire. The other end of the first heating wire is connected to one end of the heating wire. One end of the second heating wire is connected to the other end of the heating wire, and the other end of the second heating wire is grounded. The control module is used to control the power supply module to supply power to the heating wire. The control module is also used to collect the voltage across the current detection wire or current detection resistor and control the heating power of the heating wire according to the voltage across the current detection wire or current detection resistor. This invention employs a power supply module to provide a stable output current to the heating wire, and sets up a current detection wire or current detection resistor, a first heating wire wire, and a second heating wire wire connected in series. The voltage of the current detection wire or current detection resistor is collected in real time through the first and second detection terminals of the control module. The current in the heating wire series circuit is obtained from the voltage of the current detection wire or current detection resistor, and the resistance value of the heating wire can be accurately calculated, thereby achieving constant power control of the heating wire. Furthermore, the control module judges the dry burning state based on the change value of the heating wire resistance, thereby realizing the dry burning prevention function. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0038] Figure 1 This is a circuit diagram of a heating wire heating power control circuit in the prior art.

[0039] Figure 2 This is a block diagram illustrating the principle of the heating wire heating power control circuit in this invention.

[0040] Figure 3 This is a circuit diagram of the heating power control circuit for the heating wire in this invention.

[0041] Figure 4 This is a block diagram illustrating the principle of the electronic cigarette in this invention.

[0042] Figure 5 This is a circuit diagram of the charging management module, battery module, and charging interface in this invention.

[0043] Figure 6 A schematic diagram showing the connection between the heating wire heating power control circuit, the light-emitting diode, and the airflow sensor in this invention.

[0044] Figure 7 This is a flowchart illustrating the heating power control method for the heating wire in this invention. Detailed Implementation

[0045] This invention provides a heating wire power control circuit, method, and electronic cigarette. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0046] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0047] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0048] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0049] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0050] The inventors discovered that to achieve constant power control and anti-dry-burning functions in currently available electronic cigarettes, it is necessary to measure the resistance of the heating wire. There are generally two methods for measuring the heating wire resistance:

[0051] 1. A constant current source is used to inject a fixed current into the heating wire, and then the voltage on the heating wire is detected by an analog-to-digital converter module. The resistance of the heating wire is calculated according to the formula R=U / I. However, the circuit cost of the constant current source is too high.

[0052] 2. For example Figure 1 As shown, a constant current is provided to the heating wire by controlling the on / off frequency of the PMOS transistor. Then, the voltage of the heating wire (Heater) is detected by the ADC at the control terminal of the MCU, and the voltage is calculated using the formula Vpmos + V R =Vbat - Vheater, which gives the voltage across the PMOS transistor and resistor R. Then, the operating current of the heating wire is obtained using the formula I = (Vbat - Vheater) / (R + Rpmos). The resistance of the heating wire can be obtained using the formula Rheater = Vheater / Iheater. However, this calculation ignores the resistance of Rpmos, so the calculated resistance of Rheater is inaccurate. The on-resistance of the PMOS transistor will increase due to the decrease in battery voltage, which will also affect the power calculation of the heating wire. In addition, the connecting wires need to be soldered to both ends of the heating wire, and the resistance of the connecting wires will affect the calculation of the heating wire resistance, thus affecting the implementation of constant power control and anti-dry burning function.

[0053] To address the aforementioned technical problems, this invention provides a heating wire power control circuit. The heating wire power control circuit is connected to the heating wire and includes a power supply module, a current detection wire or current detection resistor, a first heating wire, a second heating wire, and a control module. The power supply module is connected to a battery voltage and is connected to the control terminal of the control module and one end of the current detection wire or current detection resistor. One end of the current detection wire or current detection resistor is also connected to the first detection terminal of the control module, and the other end of the current detection wire or current detection resistor is connected to the second detection terminal of the control module and one end of the first heating wire. The other end of the first heating wire is connected to one end of the heating wire. One end of the second heating wire is connected to the other end of the heating wire, and the other end of the second heating wire is grounded. This invention employs a power supply module to provide a stable output current to the heating wire. A current-sensing wire or resistor, a first heating wire, and a second heating wire are connected in series. In this series circuit, the on-resistance of the MOSFET is not considered; instead, the resistance of the heating wire is taken into account. The voltage of the current-sensing wire or resistor is collected in real time by the first and second detection terminals of the control module. The current in the heating wire series circuit is derived from the voltage of the current-sensing wire or resistor, allowing for accurate calculation of the heating wire's resistance. This enables constant power control of the heating wire. The control module determines the dry-burning state based on the change in the heating wire's resistance, thus achieving a dry-burning prevention function. Compared to existing technologies that use a resistor connected to the MOSFET, using a current-sensing wire to connect the heating wire saves PCB space and reduces costs.

[0054] Please also refer to Figures 2 to 3 The present invention provides a preferred embodiment of a heating wire heating power control circuit.

[0055] like Figure 2 and Figure 3As shown, this invention provides a heating wire heating power control circuit, which is connected to the heating wire and used to control the heating power of the heating wire R1. The heating wire heating power control circuit includes: a power supply module 100, a current detection wire R2 or a current detection resistor, a first heating wire R3, a second heating wire R4, and a control module 200. The power supply module 100 is connected to a battery voltage and is connected to the control terminal of the control module 200 and one end of the current detection wire R2 or the current detection resistor. One end of the current detection wire R2 or the current detection resistor is also connected to the first detection terminal of the control module 200, and the other end of the current detection wire R2 or the current detection resistor is connected to the second detection terminal of the control module 200. The measuring end is connected to one end of the first heating wire R3; the other end of the first heating wire R3 is connected to one end of the heating wire R1; one end of the second heating wire R4 is connected to the other end of the heating wire R1, and the other end of the second heating wire R4 is grounded; the control module 200 is used to control the power supply module 100 to supply power to the heating wire R1; the control module 200 is also used to collect the voltage across the current detection wire R2 or the current detection resistor and control the heating power of the heating wire according to the voltage across the current detection wire R2 or the current detection resistor.

[0056] Specifically, in some embodiments, the first detection terminal and the second detection terminal of the control module 200 in this embodiment are connected by a current detection wire R2. Compared with a resistor connection, the wire can withstand greater power and save PCB area to reduce costs (resistors have higher power and require large package resistors, which occupy too much PCB area, but resistors are easy to install. For devices with lower power requirements and larger PCB area, resistors can be used).

[0057] The power supply module 100 is connected to the battery voltage and is connected to the control terminal of the control module 200 and one end of the current detection wire R2. One end of the current detection wire R2 is also connected to the first detection terminal of the control module 200, and the other end of the current detection wire R2 is connected to the second detection terminal of the control module 200 and one end of the first heating wire R3. That is, the current detection wire R2 and the first heating wire R3 are connected in series. In addition, the other end of the first heating wire R3 is connected to one end of the heating wire R1, and one end of the second heating wire R4 is connected to the other end of the heating wire R1. The other end of the second heating wire R4 is grounded. That is, the first heating wire R3, the heating wire R1, and the second heating wire R4 are connected in series.

[0058] In specific implementation, the first and second detection terminals of the control module 200 collect the voltages Vadc1 and Vadc2 across the current detection wire R2 in real time. The current I of the series circuit is obtained using the formula I = (Vadc1 - Vadc2) / R2. The voltage V1 between the first heating wire R3 and the second heating wire R4 can be calculated using the formula V1 = I * (R3 + R4). Given the voltage V1, the second detection terminal of the control module 200 collects the voltage Vadc2 of the first heating wire R3, which is the voltage relative to ground of the first heating wire R3, heating wire R1, and second heating wire R4, i.e., Vadc2 = V... R3 +V R1 +V R4 Therefore, the resistance of the heating wire R1 can be obtained using the formula R1 = Vadc² - V1 / I. In obtaining the resistance value of the heating wire, the resistances of the first heating wire R3 and the second heating wire R4 are taken into account, allowing for an accurate calculation of the heating wire's resistance.

[0059] The accuracy of the heating wire's resistance directly affects the accuracy of subsequent constant power control and the anti-dry-burning detection function. Constant power control refers to outputting stable power. When the heating wire's resistance is determined, the control module controls the output voltage of the power supply module to adjust the voltage drop across the heating wire, keeping the power P = V2 * V2 / R1 at a constant value. This achieves precise and constant heating power output. Furthermore, by accurately detecting the heating wire's resistance, changes in the resistance can be used to determine whether dry burning has occurred.

[0060] It should be noted that the anti-dry-burning test refers to detecting the temperature of the heating wire to prevent it from burning at high temperatures. The resistance of the heating wire increases with temperature. Therefore, the higher the accuracy of the heating wire resistance, the higher the accuracy of the heating wire temperature, and thus the more accurate the anti-dry-burning test.

[0061] In some embodiments, the control module 200 is a micro control unit. The micro control unit (MCU) is a central processing unit (CPU) with its frequency and specifications appropriately reduced, integrating peripheral interfaces such as memory counter, USB, A / D conversion, UART, PLC, and DMA onto a single chip, forming a chip-level computer. It allows for different control combinations for various applications, featuring small size and low cost. Specifically, the first detection terminal ADC1 of the micro control unit is connected to one end of the current detection wire R2, and the second detection terminal ADC2 is connected to the other end of the current detection wire R2. The first detection terminal ADC1 and the second detection terminal ADC2 are used to collect the voltage across the two ends of the current detection wire.

[0062] In a further embodiment of one example, the material of the current sensing wire R2 is the same as that of the first heating wire R3 and the first heating wire R4. Specifically, the material of the current sensing wire R2 can be copper, aluminum, etc., and there is no specific limitation.

[0063] Since the two ends of the heating wire R1 need to be connected to the control board through the first heating wire wire R3 and the second heating wire wire R4, the internal resistance of the first heating wire wire R3 and the second heating wire wire R4 will cause a decrease in the voltage across the heating wire, thus affecting the calculation of the heating wire power. Therefore, the materials of the current detection wire R2, the first heating wire wire R3, and the first heating wire wire R4 are made the same. According to the law of resistance, the resistance of a conductor is proportional to its length. The resistance of the current detection wire R2 is measured by using a resistance, inductance, and capacitance tester (LRC). Then, according to the proportional algorithm, that is, according to the length ratio of the current detection wire R2 to the first heating wire wire R3 or the first heating wire wire R4, the resistance values ​​of the first heating wire wire R3 and the second heating wire R4 are obtained, thereby reducing the impact on the calculation of the heating wire R1 power.

[0064] It should be noted that if resistance is used to detect the current, the resistance values ​​of the first heating wire R3 and the second heating wire R4 need to be measured in advance.

[0065] In a further embodiment of one example, the power supply module includes: a MOSFET Q1, a first resistor R5, and a second resistor R6; wherein the drain of the MOSFET Q1 is connected to the battery voltage and is connected to one end of the first resistor R5; the gate of the MOSFET Q1 is connected to the other end of the first resistor R5 and one end of the second resistor R6; the source of the MOSFET Q1 is connected to one end of the current detection wire R2 and the first detection terminal of the control module 200; and the other end of the second resistor R6 is connected to the control terminal of the control module 200.

[0066] Specifically, the control module 200 controls the GPIO1 to output a pulse width modulation signal based on the battery voltage in the power supply module 100 and the resistance value of the heating wire R1, thereby adjusting the power supply voltage of the heating wire. When the detection terminal of the control module 200 receives the resistance value fed back from the heating wire, it outputs a PWM signal through the GPIO1 of the control module 200. The duty cycle of the PWM signal is determined by the battery voltage and the feedback resistance value of the heating wire. The PWM signal controls the on / off frequency of the MOSFET Q1, thereby controlling the output voltage of the MOSFET Q1 and controlling the voltage across the heating wire to maintain a constant output power, thus achieving a precise and constant output of heating power.

[0067] like Figures 4 to 6 As shown, in some embodiments, the present invention also provides an electronic cigarette, including the heating power control circuit of the heating wire described above, and further including: a battery module 300, a charging management module 400, and a charging interface P1; wherein, the battery module 300 is connected to the charging management module 400, the power supply module 100, and the control module 200 respectively via a V-BAT terminal, and the battery module 300 is used to supply power to the power supply module 100 and the control module 200; the charging management module 400 is connected to the control module 200 and the charging interface P1 respectively, and the charging management module 400 is used to charge the battery module 300 through the charging interface P1.

[0068] Specifically, the charging management module 400 is connected to the control terminal of the control module 200 to reflect the charging status to the control module 200. The charging interface P1 is connected to the VCC terminal of the charging management module 400, and the positive terminal of the battery in the battery module 300 is connected to the V-BAT terminal of the charging management module 400. When the battery module 300 has insufficient power, the charging management module 400 charges the battery module 300 through the charging interface P1. When the battery module 300 has sufficient power, it supplies power to the control module 200 and the power supply module 100.

[0069] In one embodiment, the charging management module 400 is a power management chip U1, and the model of the power management chip can be, but is not limited to, the 4050 series.

[0070] In one embodiment, the charging interface P1 is a TYPE-C interface.

[0071] In a further implementation of one embodiment, such as Figure 6As shown, the electronic cigarette also includes a first light-emitting diode (LED1); the first LED1 is connected to the control module 200, and the first LED1 is used to display the charging status of the electronic cigarette or the working status of the electronic cigarette.

[0072] Specifically, the first light-emitting diode (LED1) uses different flashing patterns to indicate different states, such as smoking state, charging state, etc. The flashing pattern can be that LED1 illuminates every 1 second, or it can flash rapidly then slowly; the specific pattern is not limited. Users can determine the electronic cigarette's operating status based on the flashing pattern of LED1.

[0073] like Figure 6 As shown, in a further embodiment of one example, the electronic cigarette further includes an airflow sensor P2; the airflow sensor P2 is connected to the control module 200, and the airflow sensor P2 is used to detect the smoking state and feed back the smoking state signal to the control module.

[0074] Specifically, when the airflow sensor P2 detects a smoking state (when airflow is detected), the control module 200 controls the MOS transistor of the power supply module to turn on according to the smoking state signal, thereby supplying power to the heating wire.

[0075] Please see Figure 7 The present invention also provides a method for controlling the heating power of a heating wire, wherein the step of adjusting the heating power of the heating wire by adjusting the voltage drop across the two ends of the heating wire includes:

[0076] S1. The control module controls the power supply module to supply power to the heating wire; as described in an embodiment of a heating wire heating power control circuit, it will not be repeated here.

[0077] S2. The control module detects the voltage across the current detection wire or the current detection resistor, and obtains the current flowing through the circuit based on the voltage across the current detection wire or the resistance of the current detection wire or the current detection resistor; specifically as described in an embodiment of a heating wire heating power control circuit, which will not be repeated here.

[0078] S3. The control module obtains the voltage drop of the first heating wire and the second heating wire based on the current flowing through the circuit, the resistance of the first heating wire, and the resistance of the second heating wire; as described in an embodiment of a heating wire heating power control circuit, it will not be repeated here.

[0079] S4. The voltage drop across the heating wire is obtained based on the voltage across the current detection wire or current detection resistor and the voltage drop across the first heating wire and the second heating wire; specifically as described in an embodiment of a heating wire heating power control circuit, which will not be repeated here.

[0080] S5. The control module obtains the resistance of the heating wire based on the voltage drop across the heating wire and the current flowing through the circuit.

[0081] S6. The heating power of the heating wire is adjusted by regulating the voltage drop across the heating wire. This is specifically described in an embodiment of a heating wire heating power control circuit, and will not be repeated here.

[0082] In some embodiments, step S6 includes:

[0083] S61. The control module obtains the battery voltage when the heating wire is in heating state.

[0084] S62. The control module uses pulse width modulation (PWM) to adjust the voltage across the heating wire, thereby regulating the heating power of the heating wire. Specifically, the control module determines the duty cycle of the PWM signal based on the battery voltage and the resistance of the heating wire, and controls the magnitude of the voltage across the heating wire. This is described in detail in an embodiment of a heating wire heating power control circuit, and will not be repeated here.

[0085] Step S1 is preceded by:

[0086] S01. Measure the resistance of the current sensing wire;

[0087] S02. The resistance values ​​of the first heating wire and the second heating wire are obtained by using a proportional method and based on the resistance value of the current measuring wire. This is specifically described in an embodiment of a heating wire heating power control circuit, and will not be repeated here.

[0088] In summary, the present invention provides a heating wire heating power control circuit, method, and electronic cigarette. The heating wire heating power control circuit is connected to a heating wire and includes: a power supply module, a current detection wire or a current detection resistor, a first heating wire, a second heating wire, and a control module. The power supply module is connected to a battery voltage and is connected to the control terminal of the control module and one end of the current detection wire or the current detection resistor. One end of the current detection wire or the current detection resistor is also connected to the first detection terminal of the control module, and the other end of the current detection wire or the current detection resistor is connected to the second detection terminal of the control module and one end of the first heating wire. The other end of the first heating wire is connected to one end of the heating wire. One end of the second heating wire is connected to the other end of the heating wire, and the other end of the second heating wire is grounded. The control module is used to control the power supply module to supply power to the heating wire. The control module is also used to collect the voltage across the current detection wire or the current detection resistor and control the heating power of the heating wire according to the voltage across the current detection wire or the current detection resistor. This invention provides a stable output current to the heating wire using a power supply module. A current-sensing wire or resistor, a first heating wire, and a second heating wire are connected in series. In this series circuit, the on-resistance of the MOSFET is not considered; instead, the resistance of the heating wire is taken into account. The voltage of the current-sensing wire or resistor is collected in real time by the first and second detection terminals of the control module. The current in the heating wire series circuit is derived from the voltage of the current-sensing wire or resistor, allowing for accurate calculation of the heating wire resistance. This enables constant power control of the heating wire. Furthermore, the control module determines the dry-burning state based on the change in the heating wire resistance, thus achieving a dry-burning prevention function. Compared to existing technologies that use a resistor connected in series with a MOSFET, using a current-sensing wire connected to the power supply module saves PCB space and reduces costs.

[0089] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A heating wire heating power control circuit, connected to a heating wire, for controlling the heating power of the heating wire, characterized in that, include: The power supply module, current detection wire or current detection resistor, first heating wire, second heating wire, and control module; The power supply module is connected to the battery voltage and is connected to the control terminal of the control module and one end of the current detection wire or current detection resistor, respectively. One end of the current sensing wire or current sensing resistor is also connected to the first sensing terminal of the control module, and the other end of the current sensing wire or current sensing resistor is connected to the second sensing terminal of the control module and one end of the first heating wire wire, respectively. The other end of the first heating wire wire is connected to one end of the heating wire; One end of the second heating wire is connected to the other end of the heating wire, and the other end of the second heating wire is grounded; The control module is used to control the power supply module to supply power to the heating wire; the control module is also used to collect the voltage across the current detection wire or current detection resistor in real time and control the heating power of the heating wire according to the voltage across the current detection wire or current detection resistor. The first and second detection terminals of the control module acquire the voltages Vadc1 and Vadc2 across the current detection wire R2 in real time, and then use the formula... The current I in this circuit is obtained by combining the current I with the resistances of the first heating wire R3 and the second heating wire R4 using the formula. The voltage V1 between the first heating wire R3 and the second heating wire R4 is obtained. The second detection terminal of the control module acquires the voltage Vadc2 of the first heating wire R3. From the voltages of the first heating wire R3, heating wire R1, and second heating wire R4 to ground, the following can be derived: , through formula The resistance R1 of the heating wire is then determined.

2. The heating power control circuit for the heating wire according to claim 1, characterized in that, The material of the current detection wire is the same as that of the first heating wire.

3. The heating power control circuit for the heating wire according to claim 1, characterized in that, The power supply module includes: a MOSFET, a first resistor, and a second resistor; wherein... The drain of the MOS transistor is connected to the battery voltage and is connected to one end of the first resistor; The gate of the MOS transistor is connected to the other end of the first resistor and one end of the second resistor, respectively. The source of the MOS transistor is connected to one end of the current sensing wire or the current sensing resistor and the first detection terminal of the control module, respectively. The other end of the second resistor is connected to the control terminal of the control module.

4. The heating power control circuit for the heating wire according to claim 1, characterized in that, The control module is a micro control unit.

5. An electronic cigarette, characterized in that, The heating power control circuit for the heating wire as described in any one of claims 1-4 further includes: a battery module, a charging management module, and a charging interface; wherein, The battery module is connected to the charging management module, the power supply module, and the control module respectively, and the battery module is used to supply power to the power supply module and the control module. The charging management module is connected to both the control module and the charging interface, and is used to charge the battery module through the charging interface.

6. The electronic cigarette according to claim 5, characterized in that, Also includes: First light-emitting diode; The first light-emitting diode is connected to the control module and is used to display the charging status of the electronic cigarette or the working status of the electronic cigarette.

7. The electronic cigarette according to claim 6, characterized in that, Also includes: An airflow sensor is connected to the control module and is used to detect smoking status and send a smoking status signal back to the control module.

8. A method for controlling the heating power of a heating wire applied to the heating power control circuit of any one of claims 1-4, characterized in that, include: The control module controls the power supply module to supply power to the heating wire; The control module detects the voltage across the current sensing wire or the current sensing resistor, and calculates the current flowing through the loop based on the voltage across the current sensing wire or the resistance of the current sensing wire or the current sensing resistor. The control module calculates the voltage drop of the first heating wire and the second heating wire based on the current flowing through the circuit, the resistance of the first heating wire, and the resistance of the second heating wire. The voltage drop across the heating wire is obtained by comparing the voltage across the current sensing wire or the current sensing resistor with the voltage drop across the first heating wire and the second heating wire. The control module obtains the resistance of the heating wire based on the voltage drop across the heating wire and the current flowing through the circuit. The heating power of the heating wire is adjusted by regulating the voltage drop across its two ends.

9. The heating power control method for the heating wire according to claim 8, characterized in that, The step of adjusting the heating power of the heating wire by adjusting the voltage drop across the heating wire includes: The control module acquires the battery voltage when the heating wire is in heating mode. The control module uses pulse width modulation to adjust the voltage across the heating wire, thereby regulating the heating power of the heating wire. The control module obtains the duty cycle of the pulse width modulation signal based on the battery voltage and the resistance of the heating wire.

10. The heating power control method for the heating wire according to claim 8, characterized in that, Before the step of the control module controlling the power supply module to supply power to the heating wire, the following is also included: The resistance of the current sensing wire is measured; The resistance values ​​of the first heating wire and the second heating wire are obtained by using a proportional method and based on the resistance value of the current measuring wire.

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