HNB appliance and hardware over-temperature protection circuit thereof

Abstract

The invention is suitable for the technical field of HNB appliances, and provides an HNB appliance and a hardware over-temperature protection circuit thereof, the hardware over-temperature protection circuit comprises a power regulation module, a first protection switch module, a temperature acquisition module and an over-temperature protection module; under the condition that the power adjusting module and the first protection switch module are in a conducting state, the heating body is in a heating state, the temperature acquisition module outputs an electric signal to the over-temperature protection module when the temperature of the to-be-detected equipment changes, and the over-temperature protection module outputs an over-temperature protection signal when detecting that the to-be-detected equipment is over-temperature according to the electric signal. A turn-off control signal is output to the first protection switch module so as to disconnect the heating circuit; according to the technical scheme, the over-temperature protection function is achieved through hardware, and the reliability of a protection mechanism is remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of HNB appliances, and in particular, to an HNB appliance and its hardware over-temperature protection circuit. Background Art

[0002] With the development of e-cigarette and HNB (Heat Not Burn) device technologies, more and more consumers are starting to choose this new type of smoking alternative to reduce the harmful substances generated by the combustion of traditional tobacco. The HNB technology can effectively reduce the release of toxic substances by heating rather than burning tobacco, thereby reducing the harm to the health of smokers. Although this technology shows certain advantages in improving user health and safety, existing HNB devices mainly rely on software control for over-temperature protection. When the device temperature is too high, the software control system will activate a protection mechanism to cut off the heating circuit. However, there is a risk that the software control system may have a response delay or malfunction, which may cause the protection function to fail and the circuit cannot be cut off in time, thus unable to effectively avoid damage or safety accidents caused by overheating of the device. Therefore, how to improve the reliability of over-temperature protection, especially to achieve more reliable protection through hardware, has become an important direction in the current technological development. Summary of the Invention

[0003] Embodiments of the present invention provide an HNB appliance and its hardware over-temperature protection circuit to solve the problem that when the software has problems or cannot respond in time in the prior art, the protection mechanism may fail, thereby unable to effectively prevent damage or safety accidents caused by overheating of the device.

[0004] In a first aspect of the embodiments of the present invention, a hardware over-temperature protection circuit for an HNB appliance is provided. The HNB appliance includes a heating element, and the hardware over-temperature protection circuit includes a power adjustment module, a first protection switch module, a temperature acquisition module, and an over-temperature protection module;

[0005] The heating element, the power adjustment module, and the first protection switch module form a heating circuit, and the first protection switch module and the temperature acquisition module are respectively connected to the over-temperature protection module;

[0006] When the power adjustment module and the first protection switch module are in a conducting state, the heating element is in a heating state. When the temperature of the device to be measured changes, the temperature acquisition module outputs an electrical signal to the over-temperature protection module. When the over-temperature protection module detects over-temperature of the device to be measured based on the electrical signal, it outputs a turn-off control signal to the first protection switch module to disconnect the heating circuit.

[0007] Further, the over-temperature protection module includes a detection module and a second protection switch module. The input end of the detection module is connected to the output end of the temperature acquisition module, the output end of the detection module is connected to the control end of the second protection switch module, the first end of the second protection switch module is connected to the control end of the first protection switch module, and the second end of the second protection switch module is grounded;

[0008] The temperature acquisition module outputs a first voltage to the detection module. When the detection module detects that the first voltage is greater than the reference voltage, it outputs a conduction control signal to the second protection switch module. When the second protection switch module conducts, it grounds the control end of the first protection switch module to output a turn-off control signal to the first protection switch module.

[0009] Further, the hardware over-temperature protection circuit further includes a control module, and the control module is respectively connected to the control end of the power regulation module, the control end of the first protection switch module, and the output end of the detection module;

[0010] The control module is used to output a high-level signal to the first protection switch module to make the first protection switch module conduct, output a PWM control signal to the power regulation module, and receive the conduction control signal output by the detection module.

[0011] Further, the temperature acquisition module includes an NTC thermistor and a voltage-dividing resistor. One end of the NTC thermistor receives a third voltage, the other end of the NTC thermistor and one end of the voltage-dividing resistor are commonly connected as the output end of the temperature acquisition module, and the other end of the voltage-dividing resistor is grounded.

[0012] Further, the temperature acquisition module includes a PTC thermistor and a voltage-dividing resistor. One end of the voltage-dividing resistor receives a third voltage, the other end of the voltage-dividing resistor and one end of the PTC thermistor are commonly connected as the output end of the temperature acquisition module, and the other end of the PTC thermistor is grounded.

[0013] Further, the control module is connected to the temperature acquisition module. When the control module detects that the temperature rising rate is greater than a preset value, it adjusts the duty ratio of the PWM control signal.

[0014] Further, the control module is also connected to the over-temperature protection module. The control module collects the battery temperature through the temperature acquisition module and adjusts the reference voltage and the duty ratio of the PWM control signal according to the battery temperature.

[0015] Further, the first end of the power adjustment module receives a second voltage. The second end of the power adjustment module is connected to the first end of the heating element. The second end of the heating element is connected to the first end of the first protection switch module, and the second end of the first protection switch module is grounded.

[0016] Further, the detection module includes a comparator, a fourteenth resistor, and a fifteenth resistor. One end of the fifteenth resistor is connected in common with the power supply terminal of the comparator and receives a third voltage. The other end of the fifteenth resistor is respectively connected to one end of the fourteenth resistor and the inverting input terminal of the comparator. The other end of the fourteenth resistor is grounded, and the non-inverting input terminal of the comparator is connected to the output terminal of the temperature acquisition module.

[0017] In a second aspect of the embodiments of the present invention, an HNB appliance is provided, including the hardware over-temperature protection circuit described in the first aspect.

[0018] The technical effects of the embodiments of the present invention are as follows: The hardware over-temperature protection circuit for the HNB appliance provided by this technical solution uses hardware to implement the over-temperature protection function, significantly improving the reliability of the protection mechanism. Different from the traditional over-temperature protection that relies on software control, this circuit realizes faster and more stable over-temperature detection and protection through the coordinated operation of the power adjustment module, the first protection switch module, the temperature acquisition module, and the over-temperature protection module. When the temperature of the device rises abnormally, the temperature acquisition module monitors the temperature change in real time and transmits the corresponding signal to the over-temperature protection module. The over-temperature protection module determines whether the device has overheated according to the electrical signal. If overheating occurs, it can promptly send a turn-off signal to the first protection switch module to quickly disconnect the heating circuit and prevent damage or safety accidents caused by overheating of the device. Therefore, this solution can effectively improve the safety and reliability of the HNB appliance and reduce potential risks caused by overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 FIG. 1 is a first schematic structural diagram of a hardware over-temperature protection circuit for an HNB appliance in Embodiment 1 of the present invention;

[0021] Figure 2 FIG. 2 is a second schematic structural diagram of a hardware over-temperature protection circuit for an HNB appliance in Embodiment 1 of the present invention;

[0022] Figure 3It is the third structural schematic diagram of the hardware over-temperature protection circuit of an HNB appliance in the first embodiment of the present invention;

[0023] Figure 4 It is the circuit diagram of the hardware over-temperature protection circuit of an HNB appliance in the first embodiment of the present invention;

[0024] Figure 5 It is another circuit diagram of the hardware over-temperature protection circuit of an HNB appliance in the first embodiment of the present invention;

[0025] In the figure: 101, power adjustment module; 102, heating element; 103, first protection switch module; 104, over-temperature protection module; 105, temperature acquisition module; 106, control module; 111, detection module; 112, second protection switch module. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be understood that when used in the description of the present invention specification and the appended claims, unless otherwise specified, the term " / " means "or", for example, A / B may mean A or B; herein, "and / or" is merely a description of the associated relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B, which can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0028] In the description of the present invention specification and the appended claims, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations. It should also be understood that the term "and / or" used in the description of the present invention specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0029] In addition, in the description of the present invention specification and the appended claims, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and cannot be understood as indicating or implying relative importance.

[0030] Reference to "an embodiment" or "some embodiments" or the like described in the specification of the present invention means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of the present invention. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc., which appear in different places in this specification, do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized.

[0031] It should be understood that the magnitudes of the sequence numbers of the steps in the following embodiments do not imply the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0032] For the convenience of further understanding of the technical solutions in some embodiments of the present application, the technical solutions of the HNB appliance and its hardware over-temperature protection circuit, and how the technical solutions solve the above technical problems will be described in detail below in conjunction with some specific embodiments and drawings. The embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present application.

[0033] In some embodiments, as Figure 1 shown, there is provided a hardware over-temperature protection circuit for an HNB appliance. The HNB appliance includes a heating element 102. The hardware over-temperature protection circuit includes a power adjustment module 101, a first protection switch module 103, a temperature acquisition module 105, and an over-temperature protection module 104. The heating element 102, the power adjustment module 101, and the first protection switch module 103 form a heating circuit. The first protection switch module 103 and the temperature acquisition module 105 are respectively connected to the over-temperature protection module 104. When the power adjustment module 101 and the first protection switch module 103 are in a conducting state, the heating element 102 is in a heating state. When the temperature of the device under test changes, the temperature acquisition module 105 outputs an electrical signal to the over-temperature protection module 104. When the over-temperature protection module 104 detects that the device under test is over-temperature according to the electrical signal, it outputs a turn-off control signal to the first protection switch module 103 to disconnect the heating circuit.

[0034] Among them, the main function of the power adjustment module 101 is to control the connection of the heating circuit and adjust the current of the heating circuit. When the power adjustment module 101 receives a control signal (such as a PWM control signal), it allows current to flow through the heating element 102 and starts the heating process of the heating element 102. The first protection switch module 103 works in cooperation with the power adjustment module 101 to ensure that the heating circuit is conducting under normal operating conditions. When the temperature is normal, the first protection switch module 103 and the power adjustment module 101 jointly maintain the heating state of the heating element 102; once the over-temperature protection module 104 detects abnormal temperature, the first protection switch module 103 will quickly turn off and disconnect the heating circuit. The temperature acquisition module 105 monitors the temperature of the heating element 102 or the device in real time. When the temperature changes, the temperature acquisition module 105 converts the temperature data into an electrical signal and outputs it to the over-temperature protection module 104. The over-temperature protection module 104 is the core module of the entire protection circuit. It judges whether the current temperature exceeds the preset safe range according to the electrical signal provided by the temperature acquisition module 105. If it detects that the device is over-temperature, the over-temperature protection module 104 will output a turn-off control signal to the first protection switch module 103 to cut off the heating circuit and prevent the device from being damaged due to overheating or causing safety problems.

[0035] The working process of this embodiment is as follows:

[0036] 1. When the HNB appliance starts, the power adjustment module 101 and the first protection switch module 103 are in the conducting state, current flows through the heating element 102, and heating starts. The power adjustment module 101 adjusts the current of the heating circuit according to the PWM control signal.

[0037] 2. The temperature acquisition module 105 monitors the temperature of the device to be measured in real time and converts it into an electrical signal and sends it to the over-temperature protection module 104.

[0038] 3. If the temperature rises to the preset value, the over-temperature protection module 104 judges that the device is in the over-temperature state according to the received electrical signal.

[0039] 4. When detecting that the device to be measured is over-temperature, the over-temperature protection module 104 controls the first protection switch module 103 to quickly disconnect the heating circuit through a turn-off signal, stop heating, and protect the safety of the device.

[0040] It should be noted that when designing the hardware over-temperature protection circuit, each module can adopt the following structure:

[0041] The power adjustment module 101 can be a power semiconductor device, such as a MOSFET, an IGBT or a thyristor. These devices can adjust the on / off of the current according to the control signal to control the start / stop of the heating element 102. The first protection switch module 103 can be a small relay or a MOSFET. The relay or the MOSFET is used to quickly disconnect the heating circuit to prevent overheating. When the over-temperature protection module 104 issues a turn-off signal, this module cuts off the heating current by disconnecting the circuit, thereby preventing the device from being damaged due to overheating. The temperature acquisition module 105 usually includes temperature sensors (such as thermistors, thermocouples, etc.). The thermistor (NTC or PTC) can adjust its resistance value according to the change of temperature, and thus convert it into an electrical signal. This module is responsible for monitoring the temperature of the device in real time, converting the temperature change into an electrical signal and transmitting it to the over-temperature protection module 104. The over-temperature protection module 104 can be composed of a comparator, a microcontroller or a dedicated protection IC, and monitors the temperature in combination with the output electrical signal of the temperature acquisition module 105. This module will judge the temperature signal and output a turn-off signal to the first protection switch module 103 when the temperature exceeds the preset safety value. The temperature of the device under test can be the temperature of the battery cell, the heating component or a certain position inside the machine. By monitoring the temperature change of these key components in real time, the temperature acquisition module 105 can transmit data to the over-temperature protection module in time, so as to effectively judge whether the device reaches the over-temperature threshold and start the protection mechanism. In this way, it can be ensured that when over-temperature occurs in any part of the device, the protection circuit can quickly respond and disconnect the heating circuit to prevent the device from being damaged or a safety accident from occurring.

[0042] The technical effect of this embodiment is as follows: The hardware over-temperature protection circuit of the HNB appliance provided by this technical solution uses hardware to implement the over-temperature protection function, which significantly improves the reliability of the protection mechanism. Different from the traditional over-temperature protection that relies on software control, this circuit realizes faster and more stable over-temperature detection and protection through the collaborative work of the power adjustment module 101, the first protection switch module 103, the temperature acquisition module 105 and the over-temperature protection module 104. When the temperature of the device rises abnormally, the temperature acquisition module 105 monitors the temperature change in real time and transmits the corresponding signal to the over-temperature protection module 104. The over-temperature protection module 104 judges whether the device is over-temperature according to the electrical signal. If over-temperature occurs, it can promptly send a turn-off signal to the first protection switch module 103 to quickly disconnect the heating circuit and prevent damage or safety accidents caused by device overheating. Therefore, this solution can effectively improve the safety and reliability of the HNB appliance and reduce the potential risks caused by over-temperature.

[0043] As an implementation manner, such as Figure 2As shown in the figure, the over-temperature protection module 104 includes a detection module 111 and a second protection switch module 112. The input end of the detection module 111 is connected to the output end of the temperature acquisition module 105, the output end of the detection module 111 is connected to the control end of the second protection switch module 112, the first end of the second protection switch module 112 is connected to the control end of the first protection switch module 103, and the second end of the second protection switch module 112 is grounded; the temperature acquisition module 105 outputs a first voltage to the detection module 111. When the detection module 111 detects that the first voltage is greater than the reference voltage, it outputs a conduction control signal to the second protection switch module 112. When the second protection switch module 112 is turned on, the control end of the first protection switch module 103 is grounded to output a turn-off control signal to the first protection switch module 103.

[0044] Among them, the main function of the detection module 111 is to compare the voltage signal from the temperature acquisition module 105 with a preset reference voltage. There is a functional relationship between the voltage (the first voltage) output by the temperature acquisition module 105 and the real-time temperature of the device. When the temperature reaches or exceeds the set safety threshold, the output first voltage will be greater than the reference voltage. After the detection module 111 detects this situation, it will output a control signal to control the second protection switch module 112 to start the protection operation. When the second protection switch module 112 responds to the control signal output by the detection module 111 and is turned on, the control end of the first protection switch module 103 is grounded, thereby outputting a turn-off control signal to the first protection switch module 103 to cut off the heating circuit. The working process of this embodiment is as follows: The temperature acquisition module 105 monitors the temperature of the device in real time and outputs a corresponding voltage signal (the first voltage) according to the temperature change; the detection module 111 receives the first voltage from the temperature acquisition module 105 and compares it with the set reference voltage; the reference voltage represents the temperature safety threshold. When the first voltage is greater than the reference voltage, it indicates that the device temperature has exceeded the safety range. When the detection module 111 detects that the first voltage is greater than the reference voltage, it outputs a conduction control signal to start the second protection switch module 112; after the second protection switch module 112 is turned on, the control end of the first protection switch module 103 is grounded, so that the first protection switch module 103 cannot work. Therefore, the first protection switch module 103 will output a turn-off control signal to cut off the heating circuit and stop the operation of the heating element 102.

[0045] The technical effect of this embodiment is as follows: Through the coordinated operation of the detection module 111 and the second protection switch module 112, the device can quickly respond to abnormal device temperature and cut off the heating circuit in a timely manner; when the device temperature exceeds the safety threshold, the voltage signal output by the temperature acquisition module 105 is detected by the detection module 111 and triggers the second protection switch module 112 to conduct, thereby achieving the cut-off of the heating circuit. This design ensures that the device can automatically stop heating when overheating, effectively preventing failures or safety hazards caused by overheating; at the same time, the hardware protection mechanism does not rely on the software system, enhancing the independence and stability of the system, and improving the safety and reliability of the device.

[0046] As an embodiment, as Figure 3 shown, the hardware over-temperature protection circuit further includes a control module 106. The control module 106 is respectively connected to the control end of the power adjustment module 101, the control end of the first protection switch module 103, and the output end of the detection module 111; the control module 106 is used to output a high-level signal to the first protection switch module 103 to make the first protection switch module 103 conduct, output a PWM control signal to the power adjustment module 101, and receive the conduction control signal output by the detection module 111.

[0047] Among them, the control module 106 controls the conduction of the first protection switch module 103. The control module 106 outputs a high-level signal to the control end of the first protection switch module 103 as needed to make the first protection switch module 103 conduct; enables the heating circuit to work normally and ensures that the heating element 102 is heated within a safe temperature range. The control module 106 generates a PWM control signal and outputs the PWM control signal to the power adjustment module 101 for adjusting the current magnitude in the heating circuit. The change of the PWM control signal can accurately control the power output of the heating element 102, thereby ensuring the stability and efficiency of the heating process. The control module 106 receives the conduction control signal from the detection module 111; when the temperature exceeds the set safety threshold, the detection module 111 will output a conduction control signal, and the control module 106 reacts according to this signal; when receiving the conduction control signal from the detection module 111, the control module 106 will take timely measures to issue an alarm. When overheating occurs, the control module 106 will obtain the information that the current heating circuit has been turned off through the conduction control signal received by the detection module 111, and does not need to turn off the heating circuit in a software manner.

[0048] The technical effect of this embodiment is as follows: Through the control of the control module 106, efficient and precise heating management and over-temperature protection are achieved. The control module 106 can not only adjust the heating power through the PWM signal to ensure the stability and efficiency of the heating process, but also maintain the working state of the heating circuit under normal conditions. When the temperature exceeds the safety threshold, the control module 106 receives the conduction control signal from the detection module 111, responds quickly, triggers an alarm, and automatically disconnects the heating circuit through the hardware protection mechanism without the need for software intervention to turn off, thereby improving the reliability and safety of the system. This solution effectively prevents equipment damage or safety accidents caused by overheating, and enhances the stability and intelligent level of the HNB appliance.

[0049] As an embodiment, the control module 106 is connected to the temperature acquisition module 105. When the control module 106 detects that the temperature rise rate (dT / dt) is greater than the preset value, it reduces the duty cycle of the PWM control signal or even directly shuts off the heating circuit. By monitoring the temperature change rate, the protection mechanism is triggered in advance to avoid overheating damage.

[0050] As an embodiment, the control module 106 is also connected to the over-temperature protection module 104. The control module 106 collects the battery temperature through the temperature acquisition module 105 and adjusts the reference voltage and the duty cycle of the PWM control signal according to the battery temperature.

[0051] Among them, the temperature acquisition module 105 collects the battery temperature. The control module 106 controls the heating of the HNB appliance based on the battery temperature (T_batt). In the low-temperature state (T_batt < 10°C), the PWM duty cycle is appropriately increased (such as +10%) to make up for the power loss at low temperature, and the over-temperature protection threshold is relaxed (such as +3°C) to prevent mis-triggered shutdown. At normal temperature (10°C ≤ T_batt ≤ 45°C), the standard PWM adjustment strategy is maintained without additional restrictions. In the overheat warning temperature range (45°C < T_batt < 50°C), the PWM duty cycle is reduced (such as -20%) to reduce the heating power, and the pulse heating mode is started (intermittent heating to avoid continuous temperature rise), and the over-temperature protection threshold is reduced in advance (such as -5°C) to intervene in protection earlier. In case of severe overheating (T_batt ≥ 50°C), the heating circuit is immediately turned off to prevent further battery temperature rise. After waiting for the battery temperature to recover (such as dropping to < 45°C).

[0052] In this embodiment, by detecting the battery temperature in real time, the reference voltage and PWM duty cycle are dynamically adjusted to optimize the heating strategy of the HNB appliance. In the low-temperature state, the PWM duty cycle is increased to make up for power loss, and the over-temperature protection threshold is relaxed to ensure the normal operation of the device. In the normal temperature range, the standard PWM regulation is maintained to ensure heating stability. In the overheat warning state, the PWM duty cycle is reduced, the pulse heating mode is started, and the over-temperature protection threshold is lowered in advance to improve the overheat response ability. In case of severe overheating, the heating circuit is immediately turned off to prevent further temperature rise of the battery, and heating is gradually restored after the temperature returns to the safe range. This solution improves the device safety, optimizes the energy efficiency management, reduces the over-temperature false triggering, and enhances the user experience and device reliability.

[0053] As an embodiment of the connection relationship, as Figure 4 shown, the first end of the power regulation module 101 receives the second voltage, the second end of the power regulation module 101 is connected to the first end of the heating element 102, the second end of the heating element 102 is connected to the first end of the first protection switch module 103, and the second end of the first protection switch module 103 is grounded.

[0054] Among them, in this connection relationship, the first end of the power regulation module 101 receives the second voltage VCC, and the second end is connected to the first end of the heating element T1, forming the starting part of the heating circuit. The second end of the heating element T1 is connected to the first end of the first protection switch module 103, forming another part of the heating circuit, allowing current to flow through the heating element T1. The second end of the first protection switch module 103 is grounded. The function of this connection method is to regulate the current flowing to the heating element T1 through the control of the power regulation module 101, and to disconnect at over-temperature through the first protection switch module 103, so as to achieve effective over-temperature protection and circuit state detection.

[0055] As an embodiment, as Figure 4 shown, the power regulation module 101 includes a first MOS transistor Q1 and an eleventh resistor R11. The source electrode of the first MOS transistor Q1 and one end of the eleventh resistor R11 are commonly connected as the first end of the power regulation module 101, the gate electrode of the first MOS transistor Q1 and the other end of the eleventh resistor R11 are commonly connected as the control end of the power regulation module 101, and the drain electrode of the first MOS transistor Q1 is the second end of the power regulation module 101.

[0056] Among them, the source electrode of the first MOS transistor Q1 is connected to one end of the eleventh resistor R11 to form a port for current inflow. In the circuit, the source electrode of the first MOS transistor Q1 is connected to the high-level power supply voltage VCC. The gate electrode is connected to the other end of the eleventh resistor R11 and serves as the control terminal of the first MOS transistor Q1. The voltage of the gate electrode controls the on and off states of the first MOS transistor Q1. When the gate voltage is lower than the source voltage, the first MOS transistor Q1 is turned on, allowing current to flow through; when the gate voltage approaches the source voltage, the first MOS transistor Q1 is turned off, preventing current from flowing. The drain port of the first MOS transistor Q1 is the port where current flows out of the first MOS transistor Q1, and the current flows to the heating element T1 through the drain. The eleventh resistor R11 is used to adjust the gate voltage to control the on and off of the first MOS transistor Q1. When the voltage of the gate electrode is low, the first MOS transistor Q1 is turned on, and the current flows into the heating element T1 through the drain; when the gate voltage is high, the first MOS transistor Q1 is turned off, and the current stops flowing.

[0057] As an implementation manner, as Figure 4 shown, the temperature acquisition module 105 includes an NTC thermistor NTC1 and a voltage-dividing resistor R16. One end of the NTC thermistor NTC1 receives the third voltage. The other end of the NTC thermistor NTC1 and one end of the voltage-dividing resistor R16 are commonly connected as the output terminal of the temperature acquisition module 105, and the other end of the voltage-dividing resistor R16 is grounded.

[0058] Among them, the resistance value of the NTC (Negative Temperature Coefficient) thermistor decreases as the temperature increases, and it can present a predictable resistance change law when the temperature changes. Therefore, it can be used to accurately sense the temperature. In the temperature acquisition module 105, one end of the NTC thermistor NTC1 receives the third voltage, and the other end is connected to the voltage-dividing resistor R16 to form a temperature-related voltage-dividing network. The voltage change is inversely proportional to the temperature, thereby providing a real-time temperature signal for subsequent circuit processing. The voltage-dividing resistor R16 and the NTC thermistor NTC1 together form a voltage divider, and its function is to divide the voltage across the NTC thermistor NTC1 and the third voltage to generate an output voltage proportional to the temperature. The other end of the voltage-dividing resistor R16 is grounded to provide a stable reference voltage to ensure that the output voltage can change according to the temperature response of the NTC thermistor NTC1.

[0059] The technical effect of this implementation manner is that: through the cooperation of the NTC thermistor NTC1 and the voltage-dividing resistor R16, a high-precision and low-cost temperature monitoring solution is realized, and the over-temperature protection function of the system is effectively enhanced, improving the safety and reliability of the device.

[0060] As another implementation manner, as Figure 5As shown, the temperature acquisition module 105 includes a PTC thermistor PTC1 and a voltage-dividing resistor R16. One end of the voltage-dividing resistor R16 receives the third voltage. The other end of the voltage-dividing resistor R16 and one end of the PTC thermistor PTC1 are commonly connected as the output end of the temperature acquisition module 105, and the other end of the PTC thermistor PTC1 is grounded.

[0061] Among them, the resistance value of the PTC (Positive Temperature Coefficient) thermistor increases with the increase of temperature; the PTC thermistor PTC1 has temperature dependence. When the temperature rises, its resistance will also increase. Conversely, when the temperature decreases, the resistance decreases. In the temperature acquisition module 105, one end of the PTC thermistor PTC1 is connected to the voltage-dividing resistor R16, and the other end is grounded. This configuration enables the resistance change of the PTC thermistor PTC1 to be converted into a measurable voltage signal through a voltage division network, reflecting the real-time temperature change. The function of the voltage-dividing resistor R16 is to jointly form a voltage divider with the PTC thermistor PTC1. One end of the voltage-dividing resistor receives the third voltage, and the other end is connected to one end of the PTC thermistor PTC1, so as to divide and output the voltage. Since the resistance value of the PTC thermistor PTC1 changes with the temperature, a voltage signal proportional to the temperature change can be obtained through the combination of the voltage-dividing resistor and the PTC thermistor PTC1.

[0062] The technical effect of this embodiment is that: through the cooperation of the PTC thermistor PTC1 and the voltage-dividing resistor R16, a temperature monitoring scheme with high precision and low cost is realized, and the over-temperature protection function of the system is effectively enhanced, improving the safety and reliability of the device.

[0063] As an embodiment, as Figure 4 shown, the first protection switch module 103 includes a second MOS transistor Q2 and a first capacitor C1. The source electrode of the second MOS transistor Q2 and one end of the first capacitor C1 are commonly connected as the first end of the first protection switch module 103. The gate electrode of the second MOS transistor Q2 and the other end of the first capacitor C1 are commonly connected as the control end of the first protection switch module 103. The drain electrode of the second MOS transistor Q2 is the second end of the first protection switch module 103.

[0064] Among them, the drain electrode of the second MOS transistor Q2 receives the current and is connected to the subsequent part of the heating circuit, and its gate electrode is commonly connected to the first capacitor C1 as the control end. When the gate voltage is higher than the source voltage, the second MOS transistor Q2 is turned on, and the current flows from the drain electrode to the source electrode; when the gate voltage is lower than the source voltage, the second MOS transistor Q2 is turned off, cutting off the current. The first capacitor C1 is used to smooth the gate voltage, prevent the voltage from changing too fast and causing transient problems, and ensure the stable operation of the circuit.

[0065] As an implementation, as Figure 4 shown, the detection module 111 includes a comparator U1, a fourteenth resistor R14, and a fifteenth resistor R15. One end of the fifteenth resistor R15 is commonly connected to the power supply terminal of the comparator U1 and receives a third voltage. The other end of the fifteenth resistor R15 is respectively connected to one end of the fourteenth resistor R14 and the inverting input terminal of the comparator U1. The other end of the fourteenth resistor R14 is grounded, and the non-inverting input terminal of the comparator U1 is connected to the output terminal of the temperature acquisition module 105.

[0066] Among them, the comparator U1 compares the input voltage VIN with the reference voltage and outputs a high or low level. The non-inverting input terminal is connected to the reference voltage obtained by dividing the voltage of the fourteenth resistor R14 and the fifteenth resistor R15, and the inverting input terminal is connected to the output of the temperature acquisition module. When VIN exceeds the reference voltage, U1 outputs a high level; otherwise, it outputs a low level.

[0067] As an implementation, as Figure 4 shown, the second protection switch module 112 includes a third MOS transistor Q3. The drain of the third MOS transistor Q3 is the first end of the second protection switch module 112, the source of the third MOS transistor Q3 is the second end of the second protection switch module 112, the gate of the third MOS transistor Q3 is the control end of the second protection switch module 112, and the other end of the source of the third MOS transistor Q3 is grounded.

[0068] As an implementation, the hardware over-temperature protection circuit further includes a twelfth resistor R12 and a thirteenth resistor R13. One end of the twelfth resistor R12 is connected to the control end of the first protection switch module 103. The other end of the twelfth resistor R12 and one end of the thirteenth resistor R13 are commonly connected and then connected to the output terminal of the control module 106. The other end of the thirteenth resistor R13 is connected to the output terminal of the detection module 111.

[0069] The hardware working principle of this scheme is as follows: when the power supply VDD is powered on, the comparator U1 starts to work, and the voltage VREF at the inverting input terminal of the comparator U1 is the voltage divided by the fourteenth resistor R14 and the fifteenth resistor R15 VREF, VREF = R14 × VDD / (R14 + R15), therefore, the magnitude of the voltage VREF can be changed by adjusting the resistance of the fourteenth resistor R14 and the fifteenth resistor R15. The voltage VIN at the non-inverting input terminal of the comparator U1 is the voltage divided by the thermistor NTC1 and the voltage divided by the resistor R16, VIN = R16 × VDD / (RNTC1 + R16), RNTC1 is the resistance of the thermistor NTC1. The magnitude of the first voltage VIN will change according to the change of temperature, because the thermistor NTC1 is a thermistor with a negative temperature coefficient, so the higher the temperature, the lower the resistance value of the thermistor NTC1, when the value of the voltage divided by the resistor R16 is fixed, the value of the first voltage VIN will increase with the increase of temperature. The thermistor NTC1 can be a negative temperature coefficient thermistor fixed to a battery cell or a heating component or a certain position inside the machine. When the temperature at the thermistor NTC1 is lower than the preset temperature threshold, VREF>VIN. Therefore, the comparator U1 outputs a low level, that is, VOUT is a low level. When the heating component needs to be heated, the control module needs to output a high level signal EN1 first. When EN1 is high and VOUT is low, the third MOS tube Q3 is turned off and the second MOS tube Q2 is turned on. Then the control module can turn on the first MOS tube Q1 by pulling the PWM1 signal low; after the first MOS tube Q1 is turned on, the current passes through the first MOS tube Q1, the heating element T1, and the second MOS tube Q2, and the heating process of the heating circuit starts. When the temperature is running normally and not out of control, the temperature of the thermistor NTC1 will always be below the preset temperature threshold, and the over-temperature protection circuit will not work. When the temperature is out of control, the temperature at the thermistor NTC1 will exceed the preset temperature threshold, and VIN>VREF at this time; the comparator U1 outputs VOUT as a high-level signal, and the third MOS tube Q3 will be turned on. After the third MOS tube Q3 is turned on, the G pole of the second MOS tube Q2 will be pulled down to GND; therefore, the second MOS tube Q2 will be cut off, the current stops flowing, and the heating process stops. The voltage at VOUT will jump from low level to high level after an over-temperature event occurs. The control module can also detect the over-temperature event by detecting this jump signal or high-level signal to inform the user of over-temperature. Only when the temperature drops below the preset temperature, that is, VIN<VREF, the comparator U1 outputs VOUT to output a low level. At this time, the control module can detect the low-level signal to release the over-temperature event.

[0070] like Figure 5 As shown, Figure 4The difference is that the NTC thermistor is replaced with a PTC thermistor, and the position of the voltage-dividing resistor is adjusted. The characteristic of the PTC thermistor is that the higher the temperature, the larger the resistance value. VIN = PTC1 × VDD / (PTC1 + R16), that is, the higher the temperature, the larger VIN. Therefore, using this circuit can also achieve Figure 4 the same effect as the circuit shown, which will not be elaborated here.

[0071] Embodiment 2

[0072] Embodiment 2 of the present invention provides an HNB appliance, including the hardware over-temperature protection circuit as described in Embodiment 1.

[0073] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A hardware over-temperature protection circuit for an HNB appliance, the HNB appliance including a heating element, characterized in that, The hardware over-temperature protection circuit includes a power adjustment module, a first protection switch module, a temperature acquisition module, and an over-temperature protection module; The heating element, the power adjustment module, and the first protection switch module form a heating circuit, and the first protection switch module and the temperature acquisition module are respectively connected to the over-temperature protection module; When the power adjustment module and the first protection switch module are in the conducting state, the heating element is in the heating state. When the temperature of the device under test changes, the temperature acquisition module outputs an electrical signal to the over-temperature protection module. When the over-temperature protection module detects that the device under test is over-temperature according to the electrical signal, it outputs a turn-off control signal to the first protection switch module to disconnect the heating circuit.

2. The hardware over-temperature protection circuit according to claim 1, wherein The over-temperature protection module includes a detection module and a second protection switch module. The input end of the detection module is connected to the output end of the temperature acquisition module, the output end of the detection module is connected to the control end of the second protection switch module, the first end of the second protection switch module is connected to the control end of the first protection switch module, and the second end of the second protection switch module is grounded; The temperature acquisition module outputs a first voltage to the detection module. When the detection module detects that the first voltage is greater than the reference voltage, it outputs a turn-on control signal to the second protection switch module. When the second protection switch module is turned on, the control end of the first protection switch module is grounded to output a turn-off control signal to the first protection switch module.

3. The hardware over-temperature protection circuit according to claim 2, wherein The hardware over-temperature protection circuit further includes a control module, and the control module is respectively connected to the control end of the power adjustment module, the control end of the first protection switch module, and the output end of the detection module; The control module is used to output a high-level signal to the first protection switch module to turn on the first protection switch module, output a PWM control signal to the power adjustment module, and receive the turn-on control signal output by the detection module.

4. The hardware over-temperature protection circuit according to claim 3, wherein The temperature acquisition module includes an NTC thermistor and a voltage-dividing resistor. One end of the NTC thermistor receives a third voltage, and the other end of the NTC thermistor and one end of the voltage-dividing resistor are commonly connected as the output end of the temperature acquisition module, and the other end of the voltage-dividing resistor is grounded.

5. The hardware over-temperature protection circuit according to claim 3, wherein The temperature acquisition module includes a PTC thermistor and a voltage-dividing resistor. One end of the voltage-dividing resistor receives a third voltage, and the other end of the voltage-dividing resistor and one end of the PTC thermistor are commonly connected as the output end of the temperature acquisition module, and the other end of the PTC thermistor is grounded.

6. The hardware over-temperature protection circuit according to claim 3, wherein, The control module is connected to the temperature acquisition module. When the control module detects that the temperature rising rate is greater than a preset value, it adjusts the duty ratio of the PWM control signal.

7. The hardware over-temperature protection circuit according to claim 4, wherein The control module is further connected to the over-temperature protection module. The control module acquires the battery temperature through the temperature acquisition module and adjusts the reference voltage and the duty ratio of the PWM control signal according to the battery temperature.

8. The hardware over-temperature protection circuit according to claim 3, wherein, The first end of the power adjustment module receives a second voltage. The second end of the power adjustment module is connected to the first end of the heating element. The second end of the heating element is connected to the first end of the first protection switch module. The second end of the first protection switch module is grounded.

9. The hardware over-temperature protection circuit according to claim 8, wherein, The detection module includes a comparator, a fourteenth resistor, and a fifteenth resistor. One end of the fifteenth resistor is commonly connected to the power supply terminal of the comparator and receives a third voltage. The other end of the fifteenth resistor is respectively connected to one end of the fourteenth resistor and the inverting input terminal of the comparator. The other end of the fourteenth resistor is grounded. The non-inverting input terminal of the comparator is connected to the output terminal of the temperature acquisition module.

10. An HNB device, characterized in that, It includes the hardware over-temperature protection circuit according to any one of claims 1-9.

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