HNB device and HNB device protection circuit

Abstract

This proposed technology addresses the issue of potential software protection failures in conventional HNB devices, improving the safety and stability of HNB devices and reducing the risk of failure through hardware-level protection mechanisms. [Solution] This application is applicable to the technical field of HNB devices and provides an HNB device and a protection circuit for the HNB device, the protection circuit including a first switching module, a second switching module, a voltage collection module and an overcurrent protection module, wherein when the second switching module is ON, the first switching module, upon receiving a PWM control signal, heats the heating circuit and adjusts the magnitude of the current flowing through the heating circuit based on the PWM control signal, and the overcurrent protection module, upon detecting that an overcurrent has occurred in the heating circuit based on the collected voltage output from the voltage collection module, outputs a cutoff control signal to the second switching module to turn off the heating circuit.

Description

Technical Field

[0001] The present application relates to the technical field of HNB devices, and in particular to an HNB device and a protection circuit for an HNB device.

Background Art

[0002] HNB (Heat No Burn) technology has gradually become a new technological trend in e-cigarette and HNB device products. Such products aim to reduce harmful substances generated during the combustion process of conventional cigarettes and lower the health risk to users by adopting a heating method instead of a combustion method. In conventional HNB devices, the operation of the protection circuit usually depends on software control. If a problem occurs in the software or the software cannot respond in a timely manner, the protection mechanism may become invalid, and thus damage to the device and the occurrence of safety accidents cannot be effectively prevented.

Summary of the Invention

Means for Solving the Problems

[0003] Embodiments of the present invention provide an HNB device and a protection circuit for an HNB device, which address the problem in the prior art that when a problem occurs in software or the software cannot respond in a timely manner, the protection mechanism may become invalid, and thus damage to the device and the occurrence of safety accidents cannot be effectively prevented.

[0004] A first aspect of an embodiment of the present invention provides a protection circuit for an HNB device, the protection circuit comprising a first switching module, a second switching module, a voltage acquisition module and an overcurrent protection module, the heating element, the first switching module, the second switching module and the voltage acquisition module form a first heating circuit, and the second switching module and the voltage acquisition module are respectively connected to the overcurrent protection module, When the second switching module is in the ON state, the first switching module, upon receiving a PWM control signal, heats the first heating circuit and adjusts the magnitude of the current flowing through the first heating circuit based on the PWM control signal. The overcurrent protection module, upon detecting that an overcurrent has occurred in the first heating circuit based on the collected voltage output from the voltage collection module, outputs a cutoff control signal to the second switching module to turn off the first heating circuit. Alternatively, the protection circuit further includes a temperature collection module and an over-temperature protection module. The heating element, the first switching module, and the second switching module form a second heating circuit, and the second switching module and the temperature collection module are each connected to the over-temperature protection module. When the first switching module and the second switching module are in the ON state, the heating element is in a heated state, and the temperature acquisition module outputs an electrical signal to the over-temperature protection module when the temperature of the device being measured changes. When the over-temperature protection module detects that the device being measured has overheated based on the electrical signal, it outputs a shut-off control signal to the second switching module to turn off the second heating circuit.

[0005] A second embodiment of the present invention provides an HNB device including the protective circuit described in the first embodiment.

[0006] The technical effect of the embodiment of the present invention is that, by introducing a protection circuit, this invention solves the problem that software-based overcurrent protection in conventional HNB devices may fail. The hardware protection circuit combines a first switching module, a second switching module, a voltage collection module, and an overcurrent protection module to realize a more reliable overcurrent protection mechanism. When the heating circuit is operating, the first switching module adjusts the current flow rate based on the PWM control signal, the voltage collection module continuously monitors voltage changes, and when an overcurrent situation occurs, the overcurrent protection module immediately outputs an off signal to the second switching module, quickly turning off the heating circuit and avoiding equipment damage and potential safety risks. This hardware-level protection mechanism improves the safety and stability of the HNB device and reduces the risk of failure.

[0007] To more clearly explain the technical concepts of the embodiments of the present invention, the drawings that need to be used in describing the embodiments of the present invention will be briefly described below. Obviously, the drawings in the following description are only a few embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without requiring any creative work. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the first type of protective circuit of an HNB device in Embodiment 1 of the present invention. [Figure 2] This is a schematic diagram of the second type of protective circuit of the HNB device in Embodiment 1 of the present invention. [Figure 3] This is a schematic diagram of the third type of protective circuit of the HNB device in Embodiment 1 of the present invention. [Figure 4] This is a first type circuit diagram of a protection circuit for an HNB device in Embodiment 1 of the present invention. [Figure 5] This is a diagram showing the current flow in the heating circuit of the protection circuit of the HNB device in Embodiment 1 of the present invention. [Figure 6]This is a schematic diagram of the fourth type of protective circuit for an HNB device in Embodiment 2 of the present invention. [Figure 7] This is a schematic diagram of the fifth type of protective circuit for the HNB device in Embodiment 2 of the present invention. [Figure 8] This is a schematic diagram of the sixth type of protective circuit for the HNB device in Embodiment 2 of the present invention. [Figure 9] This is a second type of circuit diagram of the protection circuit for the HNB device in Embodiment 2 of the present invention. [Figure 10] This is a third type circuit diagram of the protection circuit for the HNB device in Embodiment 2 of the present invention. [Modes for carrying out the invention]

[0009] The technical concepts in the embodiments of the present invention will be described clearly and completely below with reference to the drawings of the embodiments of the present invention, and it is clear that the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art without creative work based on the embodiments of the present invention are within the scope of the protection of the present invention.

[0010] As used in the specification and appended claims of the present invention, unless otherwise specified, the term " / " means, for example, A / B can represent A or B, and "and / or" in this specification simply indicates a related relationship that describes related subjects, and there may be three such relationships, for example, A and / or B may indicate three cases: A exists alone, A and B exist simultaneously, and B exists alone. Also, in the description of embodiments of this application, "multiple" means two or more.

[0011] In the description of the present invention and the accompanying claims, the term “including” 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 sets thereof. The term “and / or” as used in the description of the present invention and the accompanying claims refers to any combination and all possible combinations of one or more of the items listed in relation, and should also be understood to include these combinations.

[0012] Furthermore, in the description of the present invention and the attached claims, terms such as "first," "second," and "third" are used merely to distinguish between descriptions and do not indicate or imply relative importance.

[0013] When referring to "one embodiment" or "some embodiments" as described in the specification of the present invention, it means that one or more embodiments of the present invention include certain features, structures, or properties described in relation to such embodiments. Accordingly, phrases such as "in one embodiment," "in some embodiments," "in some other embodiments," and "in some other embodiments" appearing in different parts of this specification do not necessarily refer to the same embodiment, and unless otherwise specifically emphasized, they mean "one or more embodiments, but not all embodiments." The terms "includes," "incorporates," "has," and variations thereof mean "includes, but not limited to," unless otherwise specifically emphasized.

[0014] In the following embodiments, the numbering of each step does not indicate the order of execution; the execution order of each process should be determined by its function and internal logic, and does not constitute any limitation on the implementation process of the embodiments of the present invention.

[0015] To facilitate a further understanding of the technical solutions in some embodiments of the present application, the technical solutions for HNB devices and their protective circuits, and how the technical solutions solve the above-mentioned technical problems, will be described in detail below with reference to several specific embodiments and accompanying drawings. Each embodiment may be combined with one another, and the same or similar concepts or processes will not be repeated in some embodiments. Clearly, the embodiments described are some, but not all, embodiments of the embodiments of the present application.

[0016] In some embodiments, as shown in Figure 1, a protection circuit for an HNB device is provided, the HNB device includes a heating element 102, and the protection circuit includes a first switching module 101, a second switching module 103, a voltage collection module 104, and an overcurrent protection module 105. The heating element 102, the first switching module 101, the second switching module 103, and the voltage collection module 104 form a first heating circuit, and the second switching module 103 and the voltage collection module 104 are each connected to the overcurrent protection module 105. When the second switching module 103 is ON, the first switching module 101 receives a PWM control signal and heats the first heating circuit, adjusting the magnitude of the current flowing through the first heating circuit based on the PWM control signal. When the overcurrent protection module 105 detects that an overcurrent has occurred in the first heating circuit based on the collected voltage output from the voltage collection module 104, it outputs a cutoff control signal to the second switching module 103 to turn off the first heating circuit.

[0017] Here, the first switching module 101 controls the turning on / off of the first heating circuit, adjusts the magnitude of current by receiving a PWM (pulse width modulation) control signal, and forms the first heating circuit together with the heating element 102. The second switching module 103 is connected to the overcurrent protection module 105. When the overcurrent protection module 105 transmits a shutoff control signal, the second switching module 103 cuts off the current of the first heating circuit to prevent the continuous occurrence of an overcurrent condition. The on / off state of the second switching module 103 controls whether the first heating circuit can operate normally. The voltage collection module 104 monitors the voltage of the first heating circuit in real time, can detect current changes through voltage monitoring by the voltage collection module 104, and detects whether an overcurrent condition has occurred in the first heating circuit. The voltage collection module 104 transmits voltage information to the overcurrent protection module 105 as a basis for determining overcurrent. The overcurrent protection module 105 determines whether the current in the first heating circuit is overcurrent based on the voltage information provided from the voltage collection module 104. When detecting that the voltage value indicates that the current exceeds a predetermined safety range, the overcurrent protection module 105 immediately outputs a shutoff control signal to the second switching module 103 to turn off the first heating circuit, thereby preventing the heating element 102 from being damaged by overcurrent.

[0018] In this embodiment, under normal operating conditions, the first switching module 101 adjusts the magnitude of the current in the first heating circuit based on the PWM control signal it receives, and by adjusting the duty cycle of the PWM signal, it can accurately control the current flowing through the heating element 102 and adjust the heating effect of the heating element 102. The voltage collection module 104 collects the voltage signal in the first heating circuit in real time and transmits the signal to the overcurrent protection module 105. The overcurrent protection module 105 detects changes in current based on the voltage signal and monitors whether or not an overcurrent phenomenon occurs. If the overcurrent protection module 105 detects that the current in the first heating circuit has exceeded the safety range, it immediately outputs a cutoff control signal to the second switching module 103 based on its judgment of the voltage signal. After receiving the cutoff control signal, the second switching module 103 quickly disconnects the first heating circuit, stops the operation of the heating element 102, and prevents equipment damage and potential safety risks caused by excessive current. Once the overcurrent protection mechanism is triggered, the system must either return to normal operation via a restart mechanism or be manually reset to ensure it operates safely again.

[0019] The first switching module 101 typically uses semiconductor devices such as MOSFETs (field-effect transistors) or IGBTs (insulated-gate bipolar transistors), and can adjust the current flow according to the PWM control signal. By adjusting the duty cycle of the PWM control signal, the switching frequency of the MOSFET or IGBT, and the conduction time, the heating current can be precisely adjusted, ensuring that the power output of the heating element 102 matches expectations. The second switching module 103 may use a MOSFET or IGBT similar to that of the first switching module 101, or a relay or solid-state relay (SSR) may be selected and used as the switching element. The switching operation of the second switching module 103 is driven by the cutoff control signal of the overcurrent protection module 105. When an overcurrent situation is detected, the overcurrent protection module 105 transmits an off signal, and the second switching module 103 turns off the first heating circuit, quickly cuts off the current, and ensures safety. The voltage collection module 104 typically consists of a voltage divider or a current sensor (e.g., a Hall sensor or a shunt resistor), and the voltage divider or sensor collects and outputs the voltage signal in the first heating circuit. The overcurrent protection module 105 typically includes a comparator and a drive circuit, where the comparator compares the collected voltage signal with a set safety threshold, and if the voltage exceeds the safety threshold, it triggers the control logic unit to make a decision, and the drive circuit transmits an overcurrent protection signal to the second switching module 103 to perform a shutoff operation. The overcurrent protection module 105 analyzes the voltage signal with the comparator to determine whether the current exceeds the safety range, and if an overcurrent occurs, the module generates an off signal via the control logic unit, and the drive circuit transmits the off signal to the second switching module 103 to turn off the first heating circuit.

[0020] The technical effect of the present embodiment lies in that the technical solution solves the problem that software overcurrent protection in conventional HNB devices may become invalid by introducing a protection circuit. The hardware protection circuit combines a first switching module, a second switching module, a voltage acquisition module and an overcurrent protection module to implement a more reliable overcurrent protection mechanism. When the first heating circuit operates, the first switching module adjusts the current flow based on a PWM control signal, the voltage acquisition module continuously monitors voltage changes, and once an overcurrent condition occurs, the overcurrent protection module immediately outputs an off signal to the second switching module to quickly turn off the first heating circuit, thereby avoiding device damage and potential safety risks. This hardware-level protection mechanism improves the safety and stability of HNB devices and reduces the risk of failure occurrence.

[0021] As one embodiment, as shown in Figure 2, the overcurrent protection module 105 comprises a comparison module 111 and a third switching module 112. An input terminal of the comparison module 111 is connected to an output terminal of the voltage acquisition module 104, an output terminal of the comparison module 111 is connected to a control terminal of the third switching module 112, a first terminal of the third switching module 112 is connected to a control terminal of the second switching module 103, and a second terminal of the third switching module 112 is grounded. When the comparison module 111 detects that the acquired voltage is greater than a reference voltage, it outputs a conduction control signal to the third switching module 112. When the third switching module 112 is turned on, it grounds the control terminal of the second switching module 103, and outputs a cutoff control signal to the second switching module 103.

[0022] Here, the main role of the comparison module 111 is to compare the voltage signal (collected voltage) output from the voltage collection module 104 with a predetermined reference voltage. If the collected voltage is greater than the reference voltage, the comparison module 111 outputs a conduction control signal to the third switching module 112, and the comparison module 111 plays a role in overcurrent detection and is a core component in the overcurrent protection circuit. The comparison module 111 usually employs an operational amplifier or comparator and has high-precision voltage comparison capability. The main role of the third switching module 112 is to control the off state of the second switching module 103. When the comparison module 111 detects that the collected voltage is greater than the reference voltage, the third switching module 112 turns on and grounds the control terminal of the second switching module 103, causing the second switching module 103 to disconnect the circuit, interrupt the current in the first heating circuit, and prevent the overcurrent phenomenon. In the operation of this proposed technology, the voltage acquisition module 104 monitors the voltage in the first heating circuit in real time and transmits the voltage signal to the comparison module 111. The comparison module 111 compares the received acquired voltage with a set reference voltage, and if the acquired voltage exceeds the reference voltage, it indicates that an overcurrent may have occurred in the first heating circuit. In this case, the comparison module 111 outputs a conduction control signal to the third switching module 112, instructing it to report the occurrence of an overcurrent. After receiving the ON signal from the comparison module 111, the third switching module 112 turns ON and grounds the control terminal of the second switching module 103, causing the second switching module 103 to receive the OFF signal. After receiving the OFF signal, the second switching module 103 quickly turns OFF the first heating circuit, interrupting the current flow and preventing equipment damage or potential safety risks due to overcurrent.

[0023] The technical advantage of this embodiment is that, with this technical solution, when an overcurrent occurs in the first heating circuit, the circuit can be shut off in a timely manner at the hardware level, thereby effectively protecting the equipment from damage. Compared to conventional software control methods, this technical solution significantly improves the response speed and stability of overcurrent protection. The cooperation of the comparison module 111, the third switching module 112, and the second switching module 103 ensures that the current is shut off in a rapid response when an overcurrent occurs, thereby ensuring the safety of the equipment.

[0024] In one embodiment, as shown in Figure 3, the protection circuit further includes a first control module 106, which is connected to the control terminal of the first switching module 101, the control terminal of the second switching module 103, and the output terminal of the comparator module 111, respectively. The first control module 106 outputs a high-level signal to the second switching module 103 to turn it on, outputs a PWM control signal to the first switching module 101, and receives a conduction control signal output from the comparator module 111.

[0025] Here, the first control module 106 outputs a high-level signal to the second switching module 103 to cause conduction, allowing current to flow through the first heating circuit. When heating is required, the first control module 106 ensures conduction in the second switching module 103, allowing current to flow through the heating element 102. The first control module 106 provides a PWM control signal to the first switching module 101 and adjusts the amount of current in the first heating circuit by adjusting the duty cycle of the PWM control signal. This allows for precise control of the power output of the heating element 102, ensuring stability and efficiency of the heating process. The first control module 106 receives a conduction control signal output from the comparator module 111, which is triggered when the current in the first heating circuit exceeds a safety threshold. If an overcurrent occurs, the first control module 106, based on the conduction control signal received by the comparator module 111, knows that the first heating circuit is currently off, eliminating the need to turn off the first heating circuit in software.

[0026] The technical advantages of this embodiment are that overcurrent protection is achieved by hardware, avoiding the need to rely on software to turn off the first heating circuit, thereby improving the system's response speed and reliability. The first control module 106 ensures the stability of the first heating circuit during normal operation by outputting a high-level signal to the second switching module 103, and precisely adjusts the power output of the heating element 102 using a PWM control signal, thereby achieving an efficient and stable heating process. In the event of an overcurrent, the first control module 106 promptly shuts off the first heating circuit based on the conduction control signal from the comparator module 111, thereby preventing damage to the equipment due to overcurrent. This technology improves the degree of automation of overcurrent protection, reduces the risk of system failure, and ensures higher safety and faster response time by eliminating the need for software intervention when an overcurrent occurs.

[0027] In one embodiment, the first control module 106 is connected to the voltage input terminal of the comparison module 111 and outputs a reference voltage to the comparison module.

[0028] Here, the first control module 106 is further connected to the battery module, and the first control module 106 is connected to the voltage input terminal of the comparison module 111. Based on the state of charge (SOC) of the battery, it dynamically outputs different reference voltages. When the SOC of the battery is lower than a first predetermined value (e.g., SOC < 20%), it lowers the reference voltage to make overcurrent protection more sensitive. This allows for early limiting of heating power in low-energy states, avoiding over-discharge and extending battery life. When the SOC is higher than a second predetermined value (e.g., SOC > 90%), it appropriately increases the reference voltage to reduce frequent shutdowns due to misjudgments. This allows for appropriate mitigation of the heating current in a fully charged state, improving heating efficiency. Under normal battery energy levels, the SOC lies between the first and second predetermined values ​​(SOC is between 20% and 90%), the overcurrent protection threshold is maintained at a standard level, and the system operates normally according to load demand.

[0029] In one embodiment, the overcurrent protection module 105 further includes a first overcurrent protection module and a second overcurrent protection module, wherein the two input terminals of the first overcurrent protection module receive a collected voltage and a first reference voltage, respectively, and the output terminals of the first overcurrent protection module are connected to a first control module 106 and a second switching module 103, and the two input terminals of the second overcurrent protection module receive a collected voltage and a second reference voltage, respectively, and the output terminals of the second overcurrent protection module are connected to the first control module 106 and a second switching module 103, and the first reference voltage is greater than the second reference voltage, and the first control module Module 106 detects that both the first overcurrent protection module and the second overcurrent protection module have output overcurrent signals, determines that a serious overcurrent has occurred in the first heating circuit, and issues an overcurrent prompt. The first control module 106 detects that the first overcurrent protection module is not outputting an overcurrent signal, but both the first and second overcurrent protection modules are outputting overcurrent signals, determines that a minor overcurrent has occurred in the first heating circuit, restarts the second switching module, and reduces the duty cycle of the PWM control signal of the first switching module 101 until the second overcurrent protection module stops outputting an overcurrent signal.

[0030] Here, the first overcurrent protection module and the second overcurrent protection module detect and respond to different overcurrent levels in the first heating circuit, thereby achieving more accurate overcurrent management. The management process is as follows:

[0031] 1. Minor overcurrent handling: Only the second overcurrent protection module detects an overcurrent (the collected voltage exceeds the second reference voltage but does not exceed the first reference voltage), and the first control module 106 reduces the PWM duty cycle, gradually decreases the heating power, restarts the second switching module 103, and ensures normal operation after the current returns to a safe range.

[0032] 2. Severe Overcurrent Handling: If both the first and second overcurrent protection modules detect an overcurrent (the collected voltage exceeds the first reference voltage), the first control module 106 determines that a severe overcurrent has occurred, immediately turns off the second switching module 103, issues an overcurrent prompt, and prevents damage to the circuit.

[0033] 3. Dynamic adjustment and self-recovery mechanism: In the case of minor overcurrent, the first control module 106 achieves dynamic adjustment by gradually reducing the PWM duty cycle until the second overcurrent protection module stops outputting the overcurrent signal, thereby avoiding false triggering and reducing losses to the heat source.

[0034] The technical advantages of this embodiment are to avoid false triggers due to instantaneous current fluctuations, improve equipment stability, immediately shut off in the event of a serious overcurrent to prevent circuit overheating or component damage, reduce high-current shocks by gradually adjusting the PWM duty cycle, extend the lifespan of heating elements, support automatic recovery from minor overcurrents, reduce unnecessary equipment shutdowns, and improve ease of use.

[0035] In one embodiment, the first control module 106 is connected to the voltage input terminal of the first overcurrent protection module and the voltage input terminal of the second overcurrent protection module, respectively, and outputs a first reference voltage and a second reference voltage to the first overcurrent protection module and the second overcurrent protection module, respectively.

[0036] Here, the first control module 106 is connected to the voltage input terminal of the first overcurrent protection module and the voltage input terminal of the second overcurrent protection module respectively, and realizes intelligent multi-stage overcurrent protection by dynamically adjusting the first reference voltage (Vref1) and the second reference voltage (Vref2) based on the battery SOC (State of Charge, battery state of charge). The first control module 106 reads the battery SOC value (provided by the BMS), calculates the first reference voltage (Vref1) and the second reference voltage (Vref2) based on the SOC. When the SOC is higher than a first predetermined value (e.g., SOC>90%), it appropriately increases Vref1 and Vref2 to reduce false triggering. When the SOC is lower than a second predetermined value (e.g., SOC<20%), it reduces Vref1 and Vref2 to trigger protection early and prevent over-discharge. The first control module 106 provides Vref1 and Vref2 to the first overcurrent protection module and the second overcurrent protection module respectively. In a normal state (collected voltage Vsense<Vref2), the first switching module receives a PWM signal to control heating power. The second switching module is in a conducting state, allowing the first heating circuit to operate normally. For minor overcurrent (Vref1≦Vsense<Vref2), when the collected voltage Vsense exceeds Vref1 but is lower than Vref2, the first overcurrent protection module outputs a minor overcurrent signal to the first control module 106, and the first control module 106 reduces the PWM duty ratio until Vsense<Vref1, thereby decreasing the heating current. The second switching module remains conductive, avoiding complete shutdown and improving user experience. When the first control module 106 detects a minor overcurrent, it adopts a step-down policy: it reduces the PWM duty ratio by a change value of 10%, waits for 50 ms to observe whether the current recovers, and if the current is still higher than Vref1, it reduces the duty ratio by another 10% change value until the current recovers to normal. For severe overcurrent (Vsense≧Vref2), when the collected voltage Vsense exceeds Vref2, the second overcurrent protection module outputs a severe overcurrent signal to the first control module 106.The first control module 106 immediately turns off the second switching module, turns off the first heating circuit, ensures safety, and triggers an alarm prompt (e.g., LED flashing, buzzer prompt).

[0037] This solution effectively improves the safety, range, and intelligence level of HNB devices, and can provide optimal heating effects under different battery conditions.

[0038] As one embodiment of the connection relationship, as shown in Figure 4, the first terminal of the first switching module 101 receives the first voltage, the second terminal of the first switching module 101 is connected to the first terminal of the heating element 102, the second terminal of the heating element 102 is connected to the first terminal of the second switching module 103, the second terminal of the second switching module 103 is connected to the first terminal of the voltage collection module 104, and the second terminal of the voltage collection module 104 is grounded.

[0039] In this connection configuration, the first terminal of the first switching module 101 receives the first voltage VCC, and its second terminal is connected to the first terminal of the heating element 102, forming the initial part of the first heating circuit. The second terminal of the heating element 102 is connected to the first terminal of the second switching module 103, forming the other part of the first heating circuit and allowing current to flow through the heating element 102. The second terminal of the second switching module 103 is connected to the first terminal of the voltage collection module 104, and the second terminal of the voltage collection module 104 is grounded, completing the voltage collection function and monitoring voltage changes in the first heating circuit in real time. This connection configuration plays a role in achieving effective overcurrent protection and circuit state detection by adjusting the current flowing through the heating element 102 through the control of the second switching module 103 and monitoring the voltage in the circuit with the voltage collection module 104.

[0040] In one embodiment, as shown in Figure 4, the first switching module 101 includes a PMOS transistor Q1 and a first resistor R1, wherein the source of the PMOS transistor Q1 and one end of the first resistor R1 are commonly connected as the first end of the first switching module 101, the gate of the PMOS transistor Q1 and the other end of the first resistor R1 are commonly connected as the control end of the first switching module 101, and the drain of the PMOS transistor Q1 is the second end of the first switching module 101.

[0041] Here, the source of the PMOS transistor Q1 is connected to one end of the first resistor R1, forming a port through which current flows. In the circuit, the source of the PMOS transistor Q1 is connected to the high-level power supply voltage VCC. The gate is connected to the other end of the first resistor R1 and serves as the control terminal of the PMOS transistor Q1; the gate voltage controls the on and off state of the PMOS transistor Q1. When the gate voltage is lower than the source voltage, the PMOS transistor Q1 turns on and allows current to flow; when the gate voltage is close to the source voltage, the PMOS transistor Q1 turns off and blocks the flow of current. The drain port of the PMOS transistor Q1 is the port through which current flows out of the PMOS transistor Q1, and the current flows through the drain to the heating element 102. The first resistor R1 is used to adjust the gate voltage and controls the on and off state of the PMOS transistor Q1. When the gate voltage is low, the PMOS transistor Q1 turns on and current flows through the drain to the heating element 102; when the gate voltage is high, the PMOS transistor Q1 turns off and the flow of current stops.

[0042] In one embodiment, as shown in Figure 4, the second switching module 103 includes a first NMOS transistor Q2 and a first capacitor C1, wherein the source of the first NMOS transistor Q2 and one end of the first capacitor C1 are commonly connected as the first end of the second switching module 103, the gate of the first NMOS transistor Q2 and the other end of the first capacitor C1 are commonly connected as the control end of the second switching module 103, and the drain of the first NMOS transistor Q2 is the second end of the second switching module 103.

[0043] Here, the drain of the first NMOS transistor Q2 receives the inflow of current, and the gate of the first NMOS transistor Q2 is commonly connected to one end of the first capacitor C1, which acts as a control terminal. The gate voltage controls the on / off state of the first NMOS transistor Q2. When the gate voltage is higher than the source voltage, the first NMOS transistor Q2 turns on and allows current to flow. When the gate voltage is lower than the source voltage, the first NMOS transistor Q2 turns off and stops current flow, and the drain of the first NMOS transistor Q2 is connected to the subsequent part of the first heating circuit. The main function of the first capacitor C1 is to achieve gate voltage smoothing and transient control. When the control terminal voltage changes, the first capacitor C1 provides a constant time constant, making the change in gate voltage more gradual and preventing immediate circuit problems caused by excessively rapid voltage changes. When the control terminal voltage (gate voltage of the PMOS transistor) is high, the gate voltage of the first NMOS transistor Q2 is higher than the source voltage, so the first NMOS transistor Q2 turns on, and current flows from drain to source and continues to flow to the downstream circuit. When the gate voltage of the first NMOS transistor Q2 is lower than the source voltage, the first NMOS transistor Q2 turns off, and current cannot flow to the drain, thus interrupting the current flow in the first heating circuit.

[0044] As one embodiment, as shown in Figure 4, the comparison module 111 includes a comparator U1, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. One end of the sixth resistor R6 is commonly connected to the power supply terminal of the comparator U1 to receive the second voltage. The other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the inverting input terminal of the comparator U1, respectively. The other end of the seventh resistor R7 is grounded. The non-inverting input terminal of the comparator U1 is connected to the first end of the fourth resistor R4 and the first end of the fifth resistor R5, respectively. The second end of the fourth resistor R4 is the input terminal of the comparison module 111, and the second end of the fifth resistor R5 and the output terminal of the comparator U1 are commonly connected as the output terminal of the comparison module 111.

[0045] In one embodiment, as shown in Figure 4, the third switching module 112 includes a second NMOS transistor Q3, the drain of the second NMOS transistor Q3 is the first terminal of the third switching module 112, the source of the second NMOS transistor Q3 is the second terminal of the third switching module 112, the gate of the second NMOS transistor Q3 is the control terminal of the third switching module 112, and the other end of the source of the second NMOS transistor Q3 is grounded.

[0046] Here, comparator U1 compares the voltage signals at the two input terminals and outputs a high-level or low-level signal based on the comparison result. The non-inverting input terminal is connected to the terminals of the fourth resistor R4 and the fifth resistor R5, and these two resistors divide the voltage based on the first voltage received together to obtain a comparison voltage V+. The inverting input terminal is connected to the terminals of the sixth resistor R6 and the seventh resistor R7, and these resistors divide the second voltage so that the inverting input terminal receives the reference voltage. When the voltage V+ obtained by dividing the first voltage in the first heating circuit exceeds the reference voltage, the voltage at the inverting input terminal exceeds the voltage at the non-inverting input terminal, and comparator U1 outputs a high-level signal. Conversely, when the voltage at the inverting input terminal is less than the voltage at the non-inverting input terminal, the comparator outputs a low-level signal.

[0047] In one embodiment, the protection circuit further includes a second resistor R2 and a third resistor R3, where one end of the second resistor R2 is connected to the control terminal of the second switching module 103, the other end of the second resistor R2 and one end of the third resistor R3 are connected in common and then connected to the output terminal of the first control module 106, and the other end of the third resistor R3 is connected to the output terminal of the comparison module 111.

[0048] The operating principle of the hardware circuit of this proposed technology is as shown in Figure 5. After the power supply VDD is turned on, the comparator U1 starts operating. The voltage VREF at the inverting input terminal of comparator U1 is the voltage division voltage across the 6th resistor R6 and the 7th resistor R7, and since VREF = R7 × VDD / (R6 + R7), the magnitude of the voltage VREF can be changed by adjusting the values ​​of the 6th resistor R6 and the 7th resistor R7. When the heating element T1 is not operating, no current flows through the 1st resistor R1, so the voltage VSENSE is pulled down to GND by the 1st resistor R1. At this time, the voltage V+ at the non-inverting input terminal of comparator U1 is 0V, and since voltage VREF > V+, the output voltage of comparator U1 is a low-level signal, i.e., VOUT is low level. When it is necessary to heat the heating element T1, the first control module 106 must first output a high-level signal EN1. When EN1 is high and VOUT is low, the second NMOS transistor Q3 is turned off and the first NMOS transistor Q2 is turned on. Then, the first control module 106 can turn on the PMOS transistor Q1 by pulling down the PWM1 signal. After the PMOS tube Q1 is turned on, current begins to flow through the PMOS tube Q1, the heating element 102, the first NMOS tube Q2, and the eighth resistor R8. As shown in Figure 5, after the current begins to flow, a voltage is generated across the eighth resistor R8 due to the current. At this time, VSENSE = I × R8, where I is the current in the first heating circuit. At this time, since VOUT is GND, V+ = VSENSE × R5 / (R4 + R5) = I × R8 × R5 / (R4 + R5). Therefore, the larger the current I, the larger the voltage at V+. When V+ > VREF, comparator U1 outputs a high level, meaning VOUT is high. When VOUT is high, the second NMOS transistor Q3 turns on, and in this case, the G pole of the first NMOS transistor Q2 is pulled down to GND by the second NMOS transistor Q3. Consequently, the first NMOS transistor Q2 is shut off, and after the first NMOS transistor Q2 is shut off, the current flow in the first heating circuit stops, and since the current I is 0, VSENSE is pulled down to GND by the eighth resistor R8.

[0049] Furthermore, in order to avoid the first NMOS transistor Q2 frequently switching on and off after an overcurrent event occurs, VOUT needs to output a persistently high level after the overcurrent event occurs. The premise for keeping the first NMOS transistor Q2 continuously off and VOUT continuously outputting a high level is that the voltage at V+ is greater than VREF. Assuming that the voltage at EN1 at the time the EN1 pin is pulled up is VEN1, the action of the sixth resistor R6 is to raise the voltage at V+ so that the voltage V+ becomes greater than VREF, i.e., V+ = VEN1 × R4 / (R4 + R5 + R6) and V+ > VREF. Therefore, if appropriate resistance parameters are selected, VOUT will output a persistently high level after an overcurrent event occurs, i.e., the voltage at VOUT will transition from a low level to a high level after an overcurrent event occurs. Therefore, the first control module 106 can detect an overcurrent event by detecting the rising edge in VOUT. When an overcurrent event is detected, the controller pulls up the PWM1 signal to turn off the PMOS transistor Q1 and also turns off the power supply to the heating element 102. To release the overcurrent protection event, the controller needs to pull down the EN1 pin. Thus, the circuit can achieve hardware-level overcurrent protection, and the current detection threshold of the actual circuit can be adjusted by adjusting the values ​​of the first resistor R1, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7.

[0050] Example 2

[0051] As shown in Figure 6, the HNB device includes a heating element 102, and the protection circuit includes a first switching module 101, a second switching module 103, a temperature acquisition module 108, and an over-temperature protection module 107. The heating element 102, the first switching module 101, and the second switching module 103 form a second heating circuit, and the second switching module 103 and the temperature acquisition module 108 are each connected to the over-temperature protection module 107. When the first switching module 101 and the second switching module 103 are ON, the heating element 102 is in a heated state, and the temperature acquisition module 108 outputs an electrical signal to the over-temperature protection module 107 when the temperature of the device being measured changes. When the over-temperature protection module 107 detects that an over-temperature has occurred in the device being measured based on the electrical signal, it outputs a shut-off control signal to the second switching module 103 to turn off the second heating circuit.

[0052] Here, the main function of the first switching module 101 is to control the ON state of the second heating circuit and adjust the current of the second heating circuit. When the first switching module 101 receives a control signal (e.g., a PWM control signal), it allows current to flow through the heating element 102, initiating the heating process for the heating element 102. The second switching module 103 works in cooperation with the first switching module 101 to ensure that the second heating circuit conducts in a normal operating state. When the temperature is normal, the second switching module 103 and the first switching module 101 together maintain the heating state of the heating element 102. When the over-temperature protection module 107 detects a temperature anomaly, the second switching module 103 quickly turns off, turning off the second heating circuit. The temperature acquisition module 108 monitors the temperature of the heating element 102 or the equipment in real time. When the temperature changes, the temperature acquisition module 108 converts the temperature data into an electrical signal and outputs it to the over-temperature protection module 107. The over-temperature protection module 107 is the core module of the entire protection circuit and determines whether the current temperature exceeds a preset safety range based on the electrical signal provided by the temperature acquisition module 108. If it detects that the equipment has become over-temperature, the over-temperature protection module 107 outputs a shut-off control signal to the second switching module 103, shutting off the second heating circuit and preventing damage or safety problems caused by overheating of the equipment.

[0053] The operation process of this embodiment is as follows:

[0054] 1. When the HNB device is activated, the first switching module 101 and the second switching module 103 are in a conductive state, current flows through the heating element 102 and heating begins, and the first switching module 101 adjusts the current of the second heating circuit based on the PWM control signal.

[0055] 2. The temperature acquisition module 108 monitors the temperature of the device being measured in real time, converts it into an electrical signal, and transmits it to the over-temperature protection module 107.

[0056] 3. When the temperature rises to a predetermined value, the over-temperature protection module 107 determines that the device is in an over-temperature state based on the received electrical signal.

[0057] 4. If an overtemperature is detected in the equipment being measured, the overtemperature protection module 107 controls the second switching module 103 with an off signal to quickly turn off the second heating circuit, stop heating, and protect the safety of the equipment.

[0058] Furthermore, when designing a hardware over-temperature protection circuit, each module can adopt the following structure.

[0059] The first switching module 101 may be a power semiconductor device, such as a MOSFET, IGBT, or thyristor, which can control the on / off switching of current based on a control signal and control the starting and stopping of the heating element 102. The second switching module 103 may be a miniature relay or MOSFET, which is used to quickly turn off the second heating circuit to prevent overheating. When the over-temperature protection module 107 transmits an off signal, the module prevents damage to the equipment due to overheating by cutting off the heating current by turning off the circuit. The temperature acquisition module 108 typically includes a temperature sensor (e.g., a thermistor, thermocouple lamp), where the thermistor (NTC or PTC) can adjust its resistance value in response to temperature changes and convert it into an electrical signal. The module is responsible for monitoring the equipment temperature in real time and converting temperature changes into electrical signals to transmit to the over-temperature protection module 107. The over-temperature protection module 107 may consist 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 108. This module determines the temperature signal and outputs an off signal to the second switching module 103 if it exceeds a preset safety value. The temperature of the equipment being measured may be the temperature of a cell, a heating assembly, or a location inside the equipment. By monitoring the temperature changes of these critical components in real time, the temperature acquisition module 108 can transmit data to the over-temperature protection module in a timely manner, thereby effectively determining whether the equipment has reached an over-temperature threshold and activating the protection mechanism. If over-temperature occurs in any part of the equipment, the protection circuit is ensured to respond quickly and shut off the second heating circuit, preventing equipment damage or safety accidents.

[0060] The technical advantages of this embodiment are that the protection circuit according to this technology implements over-temperature protection using hardware, significantly improving the reliability of the protection mechanism. Unlike conventional over-temperature protection that relies on software control, this circuit achieves faster and more stable over-temperature detection and protection through the cooperative operation of the first switching module 101, the second switching module 103, the temperature acquisition module 108, and the over-temperature protection module 107. When the temperature of the equipment rises abnormally, the temperature acquisition module 108 monitors the temperature change in real time and transmits a corresponding signal to the over-temperature protection module 107. The over-temperature protection module 107 determines whether or not over-temperature has occurred in the equipment based on the electrical signal, and if over-temperature has occurred, it promptly sends an off signal to the second switching module 103, quickly turning off the second heating circuit and preventing damage or safety accidents due to overheating of the equipment. Therefore, this technology can effectively improve the safety and reliability of HNB equipment and reduce potential risks due to over-temperature.

[0061] In one embodiment, as shown in Figure 7, the over-temperature protection module 107 includes a detection module 113 and a protection switching module 114. The input terminal of the detection module 113 is connected to the output terminal of the temperature collection module 108, the output terminal of the detection module 113 is connected to the control terminal of the protection switching module 114, the first terminal of the protection switching module 114 is connected to the control terminal of the second switching module 103, and the second terminal of the protection switching module 114 is grounded. The temperature collection module 108 outputs a first voltage to the detection module 113, and when the detection module 113 detects that the first voltage is greater than a reference voltage, it outputs a conduction control signal to the protection switching module 114. When the protection switching module 114 is turned on, it grounds the control terminal of the second switching module 103 and outputs a cutoff control signal to the second switching module 103.

[0062] Here, the main role of the detection module 113 is to compare the voltage signal from the temperature acquisition module 108 with a preset reference voltage. The voltage output by the temperature acquisition module 108 (first voltage) is functionally related to the real-time temperature of the equipment, and if the temperature reaches or exceeds a set safety threshold, the output first voltage is greater than the reference voltage. After detecting such a situation, the detection module 113 outputs a control signal that controls the protection switching module 114 to activate protection. When the protection switching module 114 turns on in response to the control signal output from the detection module 113, it grounds the control terminal of the second switching module 103 and outputs a shut-off control signal to the second switching module 103, shutting off the second heating circuit. In this embodiment, the operation process involves the temperature acquisition module 108 monitoring the temperature of the equipment in real time and outputting a corresponding voltage signal (first voltage) in response to temperature changes. The detection module 113 receives the first voltage from the temperature acquisition module 108 and compares it with a set reference voltage, which represents the temperature safety threshold. If the first voltage is greater than the reference voltage, it indicates that the equipment temperature has exceeded the safety range. When the detection module 113 detects that the first voltage is greater than the reference voltage, it outputs a conduction control signal to activate the protection switching module 114. After the protection switching module 114 conducts, the control terminal of the second switching module 103 is grounded, preventing the second switching module 103 from operating. Therefore, the second switching module 103 outputs a shut-off control signal, shutting off the second heating circuit and stopping the operation of the heating element 102.

[0063] The technical effect of this embodiment is that, through the cooperative operation of the detection module 113 and the protection switching module 114, the second heating circuit can be shut off in a timely manner in response to abnormal temperatures in the equipment. When the equipment temperature exceeds a safety threshold, the voltage signal output from the temperature acquisition module 108 is detected by the detection module 113, triggering the protection switching module 114 to conduct, thereby shutting off the second heating circuit. This design ensures that heating is automatically stopped when the equipment overheats, effectively preventing failures or potential safety risks due to 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 equipment.

[0064] In one embodiment, as shown in Figure 8, the hardware over-temperature protection circuit further includes a second control module 109, which is connected to the control terminal of the first switching module 101, the control terminal of the second switching module 103, and the output terminal of the detection module 113, respectively. The second control module 109 outputs a high-level signal to the second switching module 103 to turn it on, outputs a PWM control signal to the first switching module 101, and receives a conduction control signal output from the detection module 113.

[0065] Here, the second control module 109 controls the conduction of the second switching module 103, and outputs a high-level signal to the control terminal of the second switching module 103 as needed, turning on the second switching module 103, allowing the second heating circuit to operate normally, and ensuring that the heating element 102 heats within a safe temperature range. The second control module 109 generates a PWM control signal and outputs a PWM control signal to the first switching module 101 to adjust the magnitude of the current in the second heating circuit. Changes in the PWM control signal allow for precise control of the power output of the heating element 102, ensuring stability and efficiency in the heating process. The second control module 109 receives a conduction control signal from the detection module 113, and if the temperature exceeds a set safety threshold, the detection module 113 outputs a conduction control signal. The second control module 109 reacts based on this signal, and upon receiving a conduction control signal from the detection module 113, the second control module 109 takes timely action and issues an alarm. If overheating occurs, the second control module 109 obtains information that the current second heating circuit is turned off based on the conduction control signal received by the detection module 113, eliminating the need to turn off the second heating circuit using software.

[0066] The technical effect of this embodiment is that, controlled by the second control module 109, it achieves efficient and accurate heating management and over-temperature protection. The second control module 109 adjusts the heating power by PWM signal, ensuring stability and efficiency of the heating process, and also maintains the operating state of the second heating circuit under normal conditions. If the temperature exceeds the safety threshold, the second control module 109 receives the conduction control signal from the detection module 113, responds quickly, triggers an alarm, and automatically turns off the second heating circuit by a hardware protection mechanism, eliminating the need for software intervention to turn it off, thereby improving the reliability and safety of the system. This technology effectively prevents equipment damage or safety accidents due to overheating and improves the stability and intelligence level of the HNB appliance.

[0067] In one embodiment, the second control module 109 is connected to the temperature collection module 108. When the second control module 109 detects that the temperature rise rate (dT / dt) is greater than a predetermined value, it reduces the duty ratio of the PWM control signal, and consequently directly turns off the second heating circuit. By monitoring the temperature change rate, the protection mechanism can be triggered early to avoid overheating damage.

[0068] In one embodiment, the second control module 109 is further connected to the over-temperature protection module 107. The second control module 109 collects the battery temperature through the temperature collection module 108, and adjusts the reference voltage and the duty ratio of the PWM control signal based on the battery temperature.

[0069] Here, the temperature collection module 108 collects the battery temperature, and the second control module 109 controls the heating policy of the HNB device based on the battery temperature (T_batt): in a low temperature state (T_batt<10°C), the PWM duty ratio is appropriately increased (e.g., +10%) to compensate for power loss at low temperatures, and the over-temperature protection threshold is relaxed (e.g., +3°C) to prevent false triggering of shut-off. At normal temperatures (10°C≦T_batt≦45°C), the standard PWM adjustment policy is maintained without additional restrictions. At overheating early warning temperatures (45°C<T_batt<50°C), the PWM duty ratio is reduced (e.g., -20%) to decrease heating power, a pulse heating mode (heating intermittently to avoid continuous temperature rise) is activated, the over-temperature protection threshold is lowered early (e.g., 5°C) to enable protective intervention earlier. In case of severe overheating (T_batt≧50°C), the second heating circuit is immediately turned off to prevent further temperature rise of the battery, and this state is maintained until the battery temperature recovers (e.g., drops below 45°C).

[0070] This embodiment detects the battery temperature in real time, dynamically adjusts the reference voltage and PWM duty cycle, optimizes the heating policy of the HNB device, increases the PWM duty cycle to compensate for power loss in low-temperature conditions, relaxes the over-temperature protection threshold to ensure normal operation of the device, maintains standard PWM adjustment within the normal temperature range to guarantee heating stability, reduces the PWM duty cycle and activates pulse heating mode in the early warning state of overheating, lowers the over-temperature protection threshold early to improve overheat response capability, immediately turns off the second heating circuit in the event of severe overheating to prevent further temperature rise of the battery, and gradually restores heating after the temperature returns to a safe range. This technology improves the safety of the device, optimizes energy efficiency management, reduces false over-temperature triggers, and enhances user experience and device reliability.

[0071] As an embodiment of the connection relationship, as shown in Figure 8, the first terminal of the first switching module 101 receives the second voltage, the second terminal of the first switching module 101 is connected to the first terminal of the heating element 102, the second terminal of the heating element 102 is connected to the first terminal of the second switching module 103, and the second terminal of the second switching module 103 is grounded.

[0072] In this connection configuration, the first terminal of the first switching module 101 receives the second voltage VCC, and its second terminal is connected to the first terminal of the heating element 102, forming the starting part of the second heating circuit. The second terminal of the heating element 102 is connected to the first terminal of the second switching module 103, forming the other part of the second heating circuit and allowing current to flow through the heating element 102. The second terminal of the second switching module 103 is grounded. This connection configuration plays a role in achieving effective over-temperature protection and circuit state detection by regulating the current flowing through the heating element 102 through the control of the first switching module 101 and turning off the second switching module 103 when it overheats.

[0073] In one embodiment, as shown in Figure 9, the temperature acquisition module 108 includes an NTC thermistor NTC1 and a voltage divider resistor R16, where one end of the NTC thermistor NTC1 receives a third voltage, the other end of the NTC thermistor NTC1 and one end of the voltage divider resistor R16 are commonly connected as the output terminals of the temperature acquisition module 108, and the other end of the voltage divider resistor R16 is grounded.

[0074] Here, the resistance of the NTC (Negative Temperature Coefficient) thermistor decreases with increasing temperature, exhibiting a predictable resistance change rule during temperature changes, thus enabling accurate temperature detection. In the temperature acquisition module 108, one end of the NTC thermistor NTC1 receives a third voltage, and the other end is connected to a voltage divider resistor R16, forming a temperature-related voltage divider network. The voltage change is inversely proportional to the temperature, thereby providing a real-time temperature signal for subsequent circuit processing. The voltage divider resistor R16, together with the NTC thermistor NTC1, constitutes a voltage divider, dividing 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 divider resistor R16 is grounded to provide a stable reference voltage, ensuring that the output voltage can change according to the temperature response of the NTC thermistor NTC1.

[0075] The technical effect of this embodiment is to realize a highly accurate and low-cost temperature monitoring method through the cooperation of the NTC thermistor NTC1 and the voltage divider resistor R16, effectively enhancing the system's over-temperature protection function and improving the safety and reliability of the equipment.

[0076] In another embodiment, as shown in Figure 10, the temperature acquisition module 108 includes a PTC thermistor PTC1 and a voltage divider resistor R16, where one end of the voltage divider resistor R16 receives a third voltage, the other end of the voltage divider resistor R16 and one end of the PTC thermistor PTC1 are commonly connected as the output terminal of the temperature acquisition module 108, and the other end of the PTC thermistor PTC1 is grounded.

[0077] Here, the resistance of a PTC (Positive Temperature Coefficient) thermistor increases with increasing temperature. The PTC thermistor PTC1 is temperature-dependent; its resistance increases as the temperature rises, and conversely, decreases as the temperature falls. In the temperature acquisition module 108, one end of the PTC thermistor PTC1 is connected to a voltage divider resistor R16, and the other end is grounded. With this configuration, the resistance change of the PTC thermistor PTC1 is converted into a measurable voltage signal via a voltage divider network, reflecting real-time temperature changes. The role of the voltage divider resistor R16 is to form a voltage divider together with the PTC thermistor PTC1. The voltage divider resistor receives a third voltage at one end and is connected to one end of the PTC thermistor PTC1 at the other end, dividing the output voltage. Since the resistance of the PTC thermistor PTC1 changes in response to temperature changes, the combination of the voltage divider resistor and the PTC thermistor PTC1 allows for the acquisition of a voltage signal proportional to the temperature change.

[0078] The technical advantage of this embodiment is that, through the cooperation of the PTC thermistor PTC1 and the voltage divider resistor R16, a highly accurate and low-cost temperature monitoring solution is realized, effectively enhancing the system's over-temperature protection function and improving the safety and reliability of the equipment.

[0079] In one embodiment, as shown in Figure 9, the detection module 113 includes a comparator U2, a 14th resistor R14, and a 15th resistor R15. One end of the 15th resistor R15 is connected to the power supply terminal of the comparator U2 to receive the third voltage. The other end of the 15th resistor R15 is connected to one end of the 14th resistor R14 and the inverting input terminal of the comparator U2, respectively. The other end of the 14th resistor R14 is grounded, and the non-inverting input terminal of the comparator U2 is connected to the output terminal of the temperature acquisition module 108.

[0080] Here, comparator U2 compares the input voltage VIN with a reference voltage and outputs either a high or low level. The non-inverting input terminal is connected to resistors R14 and R15, and the voltage is divided to obtain the reference voltage, while the inverting input terminal is connected to the temperature acquisition module for output. When VIN exceeds the reference voltage, U1 outputs a high level, and conversely, it outputs a low level.

[0081] In one embodiment, as shown in Figure 9, the protection switching module 114 includes a fourth MOS transistor Q4, the drain of the fourth MOS transistor Q4 is the first end of the protection switching module 114, the source of the fourth MOS transistor Q4 is the second end of the protection switching module 114, the gate of the fourth MOS transistor Q4 is the control end of the protection switching module 114, and the other end of the source of the fourth MOS transistor Q4 is grounded.

[0082] The hardware operating principle of this proposed technology is as follows: After the power supply VDD is turned on, comparator U2 starts operating, and the voltage VREF at the inverting input terminal of comparator U2 is the voltage divided by the 14th resistor R14 and the 15th resistor R15, and since VREF = R14 × VDD / (R14 + R15), the magnitude of the voltage VREF can be changed by adjusting the resistance values ​​of the 14th resistor R14 and the 15th resistor R15. The voltage VIN at the non-inverting input terminal of comparator U2 is the voltage divided by the thermistor NTC1 and the voltage divider resistor R16, and since VIN = R16 × VDD / (RNTC1 + R16), RNTC1 is the resistance of thermistor NTC1. The magnitude of the first voltage VIN changes with temperature, and because thermistor NTC1 is a thermistor with a negative temperature coefficient, the higher the temperature, the lower the resistance of thermistor NTC1. After the value of the voltage divider resistor R16 is fixed, the value of the first voltage VIN increases with increasing temperature. Thermistor NTC1 may be a negative temperature coefficient thermistor fixed at a location within a cell, heat-generating component, or device, and if the temperature at thermistor NTC1 is lower than the preset temperature threshold, then VREF > VIN. Therefore, comparator U2 outputs a low level, i.e., VOUT is low level. When it is necessary to heat the heating assembly, the second control module must first output a high-level signal EN1. When EN1 is high and VOUT is low, the fourth MOS transistor Q4 is turned off and the second MOS transistor Q2 is turned on. Next, the second control module can turn on the first MOS transistor Q1 by pulling down the PWM1 signal. After the first MOS transistor Q1 is turned on, current flows through the first MOS transistor Q1, the heating element 102, and the second MOS transistor Q2, initiating the heating process of the second heating circuit.When the temperature operation is normal and no thermal runaway occurs, the temperature of thermistor NTC1 is always lower than or equal to the preset temperature threshold, and the over-temperature protection circuit does not operate. After thermal runaway occurs, the temperature of thermistor NTC1 exceeds the preset temperature threshold. At this time, VIN>VREF is satisfied, comparator U2 outputs VOUT as a high-level signal, and the fourth MOS transistor Q4 is turned on. After the fourth MOS transistor Q4 is turned on, it pulls the G pole of the second MOS transistor Q2 down to GND. Therefore, the second MOS transistor Q2 is cut off, the current flow stops, and the heating process stops. The voltage at VOUT jumps from low level to high level after an over-temperature event occurs. The second control module can detect the over-temperature event by detecting this jump signal or the high-level signal, and can also notify the user of the over-temperature. Only after the temperature drops below the preset temperature, that is, when VIN<VREF is satisfied, the output VOUT of comparator U2 outputs a low level. In this case, the second control module can detect the low-level signal and clear the over-temperature event.

[0083] As shown in FIG. 10, the difference from FIG. 9 is that the NTC thermistor is changed to a PTC thermistor, and the position of the voltage dividing resistor is adjusted. The characteristic of a 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, this circuit can also achieve the same effect as the circuit shown in FIG. 4, and the description is omitted here.

[0084] Example 3

[0085] This Example 3 provides an HNB device including the protection circuit according to Example 1 or Example 2.

[0086] The above embodiments are merely for illustrative purposes and not limiting purposes. While the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications to the embodiments described above are still possible, or equivalent substitutions can be made for some of the technical features therein. Such modifications or substitutions should not cause the essence of the corresponding invention to deviate from the spirit and scope of the invention in each embodiment of the present application, and should all be included within the scope of protection of the present application. [Explanation of Symbols]

[0087] 101: First switching module, 102: Heating element, 103: Second switching module, 104: Voltage acquisition module, 105: Overcurrent protection module, 106: First control module, 107: Overtemperature protection module, 108: Temperature acquisition module, 109: Second control module, 111: Comparison module, 112: Third switching module, 113: Detection module, 114: Protection switching module

Claims

1. A protective circuit for an HNB device that includes a heating element, The protection circuit includes a first switching module and a second switching module. The protection circuit further includes a voltage collection module and an overcurrent protection module. The heating element, the first switching module, the second switching module, and the voltage collection module form a first heating circuit, and the second switching module and the voltage collection module are each connected to the overcurrent protection module. When the second switching module is in the ON state, the first switching module, upon receiving a PWM control signal, heats the first heating circuit and adjusts the magnitude of the current flowing through the first heating circuit based on the PWM control signal. The overcurrent protection module, upon detecting that an overcurrent has occurred in the first heating circuit based on the collected voltage output from the voltage collection module, outputs a cutoff control signal to the second switching module to turn off the first heating circuit. Alternatively, the protection circuit further includes a temperature collection module and an over-temperature protection module. The heating element, the first switching module, and the second switching module form a second heating circuit, and the second switching module and the temperature collection module are each connected to the over-temperature protection module. A protection circuit for an HNB device, characterized in that when the first switching module and the second switching module are in the ON state, the heating element is in a heated state, the temperature acquisition module outputs an electrical signal to the over-temperature protection module when the temperature of the device to be measured changes, and when the over-temperature protection module detects that an over-temperature has occurred in the device to be measured based on the electrical signal, it outputs a shut-off control signal to the second switching module to turn off the second heating circuit.

2. The overcurrent protection module includes a comparator module and a third switching module, wherein the input terminal of the comparator module is connected to the output terminal of the voltage collection module, the output terminal of the comparator module is connected to the control terminal of the third switching module, the first terminal of the third switching module is connected to the control terminal of the second switching module, and the second terminal of the third switching module is grounded. The protection circuit according to claim 1, characterized in that the comparison module outputs a conduction control signal to the third switching module when it detects that the collected voltage is greater than the reference voltage, and when the third switching module is turned on, it grounds the control terminal of the second switching module and outputs a cutoff control signal to the second switching module.

3. The protection circuit further includes a first control module, the first control module being connected to the control terminal of the first switching module, the control terminal of the second switching module, and the output terminal of the comparison module, respectively. The protection circuit according to claim 2, characterized in that the first control module is used to output a high-level signal to the second switching module to turn on the second switching module, to output a PWM control signal to the first switching module, and to receive a conduction control signal output from the comparator module.

4. The protection circuit according to claim 3, characterized in that the first control module is connected to the voltage input terminal of the comparison module so as to output a reference voltage to the comparison module.

5. The protection circuit according to claim 3, wherein the overcurrent protection module further includes a first overcurrent protection module and a second overcurrent protection module, the two input terminals of the first overcurrent protection module each receive a collected voltage and a first reference voltage, the output terminal of the first overcurrent protection module is connected to the first control module and the second switching module, the two input terminals of the second overcurrent protection module each receive a collected voltage and a second reference voltage, the output terminal of the second overcurrent protection module is connected to the first control module and the second switching module, and the first reference voltage is greater than the second reference voltage.

6. The protection circuit according to claim 5, characterized in that the first control module is connected to the voltage input terminal of the first overcurrent protection module and the voltage input terminal of the second overcurrent protection module, respectively, and outputs the first reference voltage and the second reference voltage to the first overcurrent protection module and the second overcurrent protection module, respectively.

7. The protection circuit according to claim 3, characterized in that the first terminal of the first switching module receives a first voltage, the second terminal of the first switching module is connected to the first terminal of a heating element, the second terminal of the heating element is connected to the first terminal of the second switching module, the second terminal of the second switching module is connected to the first terminal of the voltage collection module, and the second terminal of the voltage collection module is grounded.

8. The first switching module includes a PMOS transistor and a first resistor, the source of the PMOS transistor and one end of the first resistor are commonly connected as the first end of the first switching module, the gate of the PMOS transistor and the other end of the first resistor are commonly connected as the control end of the first switching module, and the drain of the PMOS transistor is the second end of the first switching module. The second switching module includes a first NMOS transistor and a first capacitor, wherein the source of the first NMOS transistor and one end of the first capacitor are commonly connected as the first end of the second switching module, the gate of the first NMOS transistor and the other end of the first capacitor are commonly connected as the control end of the second switching module, and the drain of the first NMOS transistor is the second end of the second switching module. The protection circuit according to claim 7, wherein the comparison module includes a comparator, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor, one end of the sixth resistor is commonly connected to the power supply terminal of the comparator and receives a second voltage, the other end of the sixth resistor is connected to one end of the seventh resistor and the inverting input terminal of the comparator, respectively, the other end of the seventh resistor is grounded, the non-inverting input terminal of the comparator is connected to the first end of the fourth resistor and the first end of the fifth resistor, respectively, the second end of the fourth resistor is the input terminal of the comparison module, and the second end of the fifth resistor and the output terminal of the comparator are commonly connected as the output terminal of the comparison module.

9. The over-temperature protection module includes a detection module and a protection switching module, wherein the input terminal of the detection module is connected to the output terminal of the temperature collection module, the output terminal of the detection module is connected to the control terminal of the protection switching module, the first terminal of the protection switching module is connected to the control terminal of the second switching module, and the second terminal of the protection switching module is grounded. The protection circuit according to claim 1, characterized in that the temperature acquisition module outputs a first voltage to the detection module, the detection module outputs a conduction control signal to the protection switching module when it detects that the first voltage is greater than a reference voltage, and when the protection switching module is turned on, it grounds the control terminal of the second switching module and outputs a cutoff control signal to the second switching module.

10. The over-temperature protection module further includes a second control module connected to the control terminal of the first switching module, the control terminal of the second switching module, and the output terminal of the detection module, respectively. The protection circuit according to claim 9, characterized in that the second control module is used to turn on the second switching module by outputting a high-level signal to the second switching module, to output a PWM control signal to the first switching module, and to receive a conduction control signal output from the detection module.

11. The temperature acquisition module includes an NTC thermistor and a voltage divider resistor, one end of the NTC thermistor receives a third voltage, the other end of the NTC thermistor and one end of the voltage divider resistor are commonly connected as the output terminals of the temperature acquisition module, and the other end of the voltage divider resistor is grounded. Alternatively, the protection circuit according to claim 9, wherein the temperature acquisition module includes a PTC thermistor and a voltage divider resistor, one end of the voltage divider resistor receives a third voltage, the other end of the voltage divider resistor and one end of the PTC thermistor are commonly connected as the output terminal of the temperature acquisition module, and the other end of the PTC thermistor is grounded.

12. The protection circuit according to claim 10, wherein the second control module is connected to the temperature acquisition module, and the second control module adjusts the duty cycle of the PWM control signal when it detects that the temperature rise rate is greater than a predetermined value.

13. The protection circuit according to claim 10, wherein the second control module is further connected to an over-temperature protection module, the second control module collects the battery temperature using the temperature collection module, and adjusts the duty cycle of the reference voltage and the PWM control signal based on the battery temperature.

14. The first terminal of the first switching module receives a second voltage, the second terminal of the first switching module is connected to the first terminal of the heating element, the second terminal of the heating element is connected to the first terminal of the second switching module, and the second terminal of the second switching module is grounded. The protection circuit according to claim 9, wherein the detection module includes a comparator, a 14th resistor, and a 15th resistor, one end of the 15th resistor and the power supply terminal of the comparator are in common to receive a third voltage, the other end of the 15th resistor is connected to one end of the 14th resistor and the inverting input terminal of the comparator, the other end of the 14th resistor is grounded, and the non-inverting input terminal of the comparator is connected to the output terminal of the temperature collection module.

15. An HNB device characterized by including the protective circuit described in claim 1.

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