Heating over-temperature control method

Abstract

The invention discloses a heating over-temperature control method, and relates to the technical field of over-temperature control, and the method comprises the steps: obtaining a first voltage signal representing the current temperature of a heated device; the first voltage signal is input into the in-phase input end of the comparison circuit and compared with a second voltage signal of the inverted input end of the comparison circuit, if the first voltage signal is higher than the second voltage signal, the comparison circuit outputs a high level to control the switching device to be switched on, and the heated device continues to be heated; and when the first voltage signal is lower than the second voltage signal, the comparison circuit outputs a low level to control the switching device to be switched off, and the heated device stops heating. The technical problems that in the prior art, software control depends on an MCU, the design is complex, and the cost is high are solved, and by introducing a hardware control mechanism based on a comparison circuit, the technical effect that over-temperature protection control in the heating process is achieved while the design and production cost is reduced is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of overtemperature control, and in particular to a heating overtemperature control method. Background Art

[0002] Existing heating overtemperature control solutions utilize a microcontroller unit (MCU) for temperature monitoring and heating control. These solutions use a thermistor (such as an NTC) to collect temperature information from the heated device. The NTC and a fixed resistor form a voltage divider circuit, and the voltage at the divider point is input to the MCU's analog sampling pin for voltage sampling. The MCU continuously runs a program to analyze voltage changes to determine whether the temperature exceeds a preset upper limit. If the temperature exceeds the upper limit, the MCU controls a switching device (such as a MOSFET) to disconnect the heating circuit, thereby implementing overtemperature protection.

[0003] However, this approach requires MCU programming and firmware burning, which involves software algorithm design and debugging, increasing design complexity. Furthermore, the cost of the MCU, peripheral circuit resources, and production debugging process also increase overall manufacturing costs, making it unsuitable for cost-sensitive applications or those with simple functional requirements. Summary of the Invention

[0004] The present application provides a heating overtemperature control method, which is used to solve the technical problem that the existing technology relies on MCU for software control, which is complex in design and high in cost.

[0005] In view of the above problems, the present application provides a heating overtemperature control method.

[0006] The present application provides a heating overtemperature control method, the method comprising:

[0007] Acquire a first voltage signal representing the current temperature of the heated device; input the first voltage signal into the non-inverting input terminal of the comparison circuit, and compare it with the second voltage signal at the inverting input terminal of the comparison circuit; if the first voltage signal is higher than the second voltage, the comparison circuit outputs a high level to control the switching device to turn on, and the heated device continues to be heated; when the first voltage signal is lower than the second voltage, the comparison circuit outputs a low level to control the switching device to turn off, and the heated device stops being heated.

[0008] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0009] The present application obtains a first voltage signal representing the current temperature of the heated device; inputs the first voltage signal into the non-inverting input terminal of the comparison circuit, and compares it with the second voltage signal at the inverting input terminal of the comparison circuit; if the first voltage signal is higher than the second voltage, the comparison circuit outputs a high level to control the switching device to turn on, and the heated device continues to heat; when the first voltage signal is lower than the second voltage, the comparison circuit outputs a low level to control the switching device to turn off, and the heated device stops heating. The present invention solves the technical problem of relying on MCU for software control, complex design, and high cost in the prior art. By introducing a hardware control mechanism based on the comparison circuit, the technical effect of realizing over-temperature protection control during the heating process while reducing design and production costs is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 A schematic flow chart of a heating overtemperature control method provided in an embodiment of the present application;

[0012] Figure 2 A heating overtemperature control circuit diagram applied to a heating overtemperature control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0013] This application provides a heating overtemperature control method to solve the technical problems in the existing technology that rely on MCU for software control, which is complex in design and high in cost. By introducing a hardware control mechanism based on a comparison circuit, the technical effect of realizing overtemperature protection control during the heating process is achieved while reducing design and production costs.

[0014] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0015] It should be noted that any variations of the terms "include" and "have" are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or modules that are not clearly listed or are inherent to these processes, methods, products or devices.

[0016] Examples, such as Figure 1 As shown, the present application provides a heating overtemperature control method, which is applied to a heating overtemperature control circuit, wherein the heating overtemperature control circuit includes a heated device, a comparison circuit, and a switching device, and the method includes:

[0017] Step S100: obtaining a first voltage signal representing the current temperature of the heated component.

[0018] In the embodiments of this application, Figure 2 As shown, the heating overtemperature control circuit includes a heated device, a comparison circuit and a switch device Q1.

[0019] The first voltage signal representing the current temperature of the heated device is generated by a voltage divider circuit composed of a thermistor and a fixed resistor connected in series. Specifically, the thermistor (denoted as R T ) and a fixed resistor (denoted as R1) are connected between the original temperature measurement voltage V1, and the divided voltage is output at the connection node between the two, which is the first voltage signal V + .

[0020] The first voltage signal V + The calculation formula is Among them, V + is the first voltage signal, which represents the voltage at the non-inverting input terminal of the comparison circuit. V1 is the original temperature measurement voltage of the voltage divider circuit. R T is the resistance value of the thermistor, and R1 is the resistance value of the fixed resistor.

[0021] Step S200: Input the first voltage signal into the non-inverting input terminal of the comparison circuit and compare it with the second voltage signal at the inverting input terminal of the comparison circuit. If the first voltage signal is higher than the second voltage signal, the comparison circuit outputs a high level to control the switching device to turn on, and the heated device continues to be heated.

[0022] In the embodiment of the present application, the first voltage signal is input to the non-inverting input terminal (+ input terminal) of the comparison circuit, and the inverting input terminal (- input terminal) of the comparison circuit is connected to the preset second voltage signal V ref , the V ref It is a fixed reference voltage, which represents the voltage threshold corresponding to the upper limit of the temperature allowed by the heated device.

[0023] Comparison circuit to V + and V ref The two are compared in real time. + >V ref When the current temperature is below the preset upper limit, the comparison circuit outputs a high-level signal, turning on the switch Q1. The switch is preferably a semiconductor field-effect transistor (MOSFET), with its gate connected to the output of the comparison circuit. Driven by the high-level signal, the MOSFET turns on, energizing the heating film connected therebetween and continuing to heat the heated component.

[0024] Step S300: When the first voltage signal is lower than the second voltage, the comparison circuit outputs a low level to control the switch device to be turned off, and the heated device stops heating.

[0025] In the embodiment of the present application, when the temperature of the heated device gradually increases, the resistance value R of the negative temperature coefficient thermistor (NTC) attached to the surface of the heated device increases. T As the temperature rises, it decreases. Since the NTC and the fixed resistor are connected in series to form a voltage divider circuit, the first voltage signal V + Will change with the NTC resistance R T The voltage gradually decreases with the decrease of the temperature, forming a voltage representation of the current temperature state. + The signal is input to the non-inverting input terminal of the comparison circuit in real time, and the second voltage signal V set at the inverting input terminal is ref Make a comparison.

[0026] When V + Gradually decreases to below V ref , indicating that the current temperature has reached or exceeded the set upper limit, the comparator circuit outputs a low-level signal, which is connected to the gate of the switching device Q1, turning it from the on state to the off state, thereby severing the circuit between the heating film and the heating source. At this point, the heating film stops working, and the temperature of the heated device no longer rises, achieving over-temperature protection control during the heating process.

[0027] Furthermore, the method provided in the application embodiment also includes:

[0028] The first voltage signal is output by calculating the original temperature measurement voltage of the voltage divider circuit; wherein the voltage divider circuit is composed of a thermistor and a fixed resistor connected in series, and the thermistor is used to measure the temperature of the heated device.

[0029] Furthermore, the method provided in the application embodiment also includes:

[0030] The thermistor is a negative temperature coefficient thermistor NTC.

[0031] In the embodiment of the present application, the first voltage signal V +The original temperature measurement voltage is divided and calculated by a voltage divider circuit and then output. The voltage divider circuit is composed of a thermistor and a fixed resistor in series. The thermistor uses a negative temperature coefficient thermistor (NTC), whose resistance decreases as the temperature of the heated device increases.

[0032] One end of the voltage divider circuit is connected to the constant original temperature measurement voltage source V1, and the other end is grounded. The connection node between the two resistors outputs the first voltage signal V + .

[0033] Since the NTC is placed close to the heated device, its resistance change can reflect the device temperature change in real time, so that the output V + This structure directly utilizes the resistance change relationship between the NTC and the fixed resistor to physically divide the original temperature measurement voltage, converting temperature information into a voltage signal, providing the basic input for subsequent comparison and control.

[0034] Furthermore, in the method provided in the embodiment of the application, the first voltage signal is calculated and outputted through the original temperature measurement voltage of the voltage divider circuit, and the calculation formula of the first voltage signal is:

[0035]

[0036] Among them, V + is the first voltage signal, representing the voltage at the non-inverting input terminal of the comparison circuit, V1 is the original temperature measurement voltage of the voltage divider circuit, R T is the resistance value of the thermistor, and R1 is the resistance value of the fixed resistor.

[0037] In the embodiment of the present application, in order to obtain the first voltage signal representing the current temperature of the heated device, a thermistor R is constructed. T The voltage divider circuit is composed of a fixed resistor R1 in series, and a stable original temperature measurement voltage V1 is applied at both ends. T The connection node forms a voltage sampling point, and the voltage output by the sampling point is the first voltage signal V + .

[0038] The calculation formula of the first voltage signal is: Among them, V + is the first voltage signal, which represents the voltage at the non-inverting input terminal of the comparison circuit; V1 is the original temperature measurement voltage of the voltage divider circuit, R T is the resistance value of the thermistor, R1 is the resistance value of the fixed resistor. By calculating with this formula, the first voltage signal V representing the current temperature of the heated device is obtained. + .

[0039] Furthermore, the method provided in the application embodiment also includes:

[0040] The comparison circuit further includes a positive feedback resistor, wherein the output terminal of the comparison circuit is connected to the non-inverting input terminal of the comparison circuit through the positive feedback resistor, and the comparison circuit performs hysteresis control through the positive feedback resistor.

[0041] In the embodiment of the present application, in order to improve the stability of the heating control process, the comparison circuit introduces a positive feedback resistor R f , used to realize the hysteresis control function. Specifically, the output of the comparison circuit is connected to the positive feedback resistor R f Connect to its non-inverting input terminal (+ terminal) to form a positive feedback loop.

[0042] In this structure, when the first voltage signal V + Higher than the second voltage signal V at the inverting input terminal of the comparison circuit ref When , the comparison circuit outputs a high level, controlling the switch device Q1 to turn on. At this time, the output high level signal is fed back to the non-inverting input terminal through the positive feedback resistor, further raising the voltage of the input terminal, strengthening the maintenance of the high level output state of the first voltage signal, and avoiding false triggering due to small fluctuations. On the contrary, when the first voltage signal V + Lower than the second voltage signal V ref When , the comparison circuit outputs a low level, and the feedback effect of the positive feedback resistor reduces the voltage at the non-inverting input terminal, thereby enhancing the effect of maintaining the low level state.

[0043] The positive feedback mechanism introduces a positive feedback resistor R by connecting the output of the comparator circuit to its non-inverting input. f The hysteresis characteristic dynamically adjusts the non-inverting input voltage as the first voltage signal approaches the second voltage signal, thereby forming two distinct switching thresholds within the comparator circuit. One threshold triggers the high-level output during the rising phase of the first voltage signal, while the other triggers the low-level output during the falling phase. This hysteresis effectively expands the voltage judgment range, preventing frequent output flip-flops at critical points and achieving stable control of the heating process.

[0044] Furthermore, the method provided in the application embodiment also includes:

[0045] The calculation formula of the first voltage signal is:

[0046]

[0047] Among them, V + is the first voltage signal, representing the voltage at the non-inverting input terminal of the comparison circuit, V1 is the original temperature measurement voltage of the voltage divider circuit, R T is the resistance value of the thermistor, R1 is the resistance value of the fixed resistor, R f is the resistance value of the positive feedback resistor, Vout is the output voltage of the comparison circuit, and the output voltage includes a low level or a high level.

[0048] In the embodiment of the present application, the first voltage signal V + Not only is it generated by the voltage divider circuit, but a positive feedback regulation mechanism is also introduced. Specifically, the first voltage signal V + The thermistor R T The output of the voltage divider circuit formed in series with the fixed resistor R1, combined with the positive feedback resistor R f Dynamic adjustment of voltage. One end of the voltage divider is connected to the original temperature measurement voltage V1, and the other end is grounded. T The connection node with R1 outputs V + , and this node is also connected to the positive feedback resistor R f , and the other end is connected to the output of the comparison circuit.

[0049] Under the positive feedback structure, the first voltage signal V + The calculation formula is as follows:

[0050] Among them, V + is the first voltage signal, i.e. the input voltage of the non-inverting input terminal of the comparison circuit; V1 is the original temperature measurement voltage of the voltage divider circuit; R T is the resistance value of the thermistor; R1 is the resistance value of the fixed resistor; R f is the resistance value of the positive feedback resistor; V out The output voltage of the comparison circuit can be high or low.

[0051] Furthermore, the method provided in the application embodiment also includes:

[0052] The positive feedback resistor is an adjustable resistor, and the resistance value of the positive feedback resistor ranges from [100 kΩ to 200 kΩ].

[0053] In an embodiment of the present application, a positive feedback resistor is set to an adjustable resistor. The positive feedback resistor is connected between the output terminal and the in-phase input terminal of the comparison circuit, and is used to introduce feedback regulation of the output signal to the input terminal, thereby constructing a hysteresis control mechanism. By adjusting the resistance of the positive feedback resistor, the size of the hysteresis voltage inside the comparison circuit can be directly affected, thereby controlling the voltage threshold interval corresponding to the heating start and stop. The resistance value range of the positive feedback resistor is [100kΩ, 200kΩ]. A lower resistance (such as close to 100kΩ) can enhance the positive feedback effect and expand the hysteresis interval, which is suitable for scenes with large temperature fluctuations; a higher resistance (such as close to 200kΩ) weakens the feedback effect and narrows the hysteresis range, which is suitable for occasions with higher control accuracy requirements. By setting the adjustment range, effective control of the hysteresis interval of the comparison circuit can be achieved, and frequent switching of the output can be avoided due to small temperature fluctuations.

[0054] Furthermore, the method provided in the application embodiment also includes:

[0055] The switching device is a semiconductor field effect transistor, and a gate of the semiconductor field effect transistor is connected to the output end of the comparison circuit.

[0056] In the embodiments of the present application, the switching device is a semiconductor field-effect transistor (MOSFET), which has the characteristics of high input impedance, low on-resistance, and fast switching speed, making it suitable for use as a control switch in the circuit. The gate of the MOSFET is connected to the output terminal of the comparator circuit to receive the control signal from the comparator circuit.

[0057] In actual operation, the comparator circuit compares the first voltage signal with the second voltage signal. When the first voltage signal is higher than the second voltage signal, indicating that the current temperature of the heated device is below a set threshold, the comparator circuit outputs a high-level signal. This high-level signal is applied to the gate of the semiconductor field-effect transistor, turning it on. Once turned on, it drives the heating film to connect to the heating source, initiating the heating process. Conversely, when the first voltage signal is lower than the second voltage signal, indicating that the temperature reaches or exceeds the set upper limit, the comparator circuit outputs a low-level signal, the gate voltage drops, and the semiconductor field-effect transistor turns off, severing the heating circuit.

[0058] Furthermore, the method provided in the application embodiment also includes:

[0059] The heated device is heated by the heating film; when the switching device is turned on, the heating film is connected to the heating source, and the heated device continues to be heated; when the switching device is closed, the heating film is disconnected from the heating source, and the heated device stops being heated.

[0060] In this embodiment, the heated device is heated by a heating film. The heating film is a flexible, adhesive heating element that converts electrical energy into heat and transfers it uniformly to the surface of the heated device, ensuring normal operation in low-temperature environments. To dynamically control the heating process, one end of the heating film is connected to a heat source, and the other end is connected in series with a switching device.

[0061] During operation, when the comparison circuit outputs a high-level signal, the switching device (semiconductor field-effect transistor) turns on, forming a current path between the heating film and the heating source. Current flows through the heating film, releasing heat and continuously heating the heated device. Conversely, when the first voltage signal is lower than the second voltage signal, the comparison circuit outputs a low-level signal, controlling the switching device to turn off. The circuit between the heating film and the heating source is cut off, the current is interrupted, the heat generation stops, and the heated device stops heating.

[0062] This control method directly drives the switching device on and off by comparing the output status of the circuit, thereby controlling whether the heating film is powered on, forming a closed-loop control mechanism based on temperature feedback.

[0063] In the embodiments of the present application, in summary, the embodiments of the present application have at least the following technical effects:

[0064] The present application obtains a first voltage signal representing the current temperature of the heated device; inputs the first voltage signal into the non-inverting input terminal of the comparison circuit, and compares it with the second voltage signal at the inverting input terminal of the comparison circuit; if the first voltage signal is higher than the second voltage, the comparison circuit outputs a high level to control the switching device to turn on, and the heated device continues to heat; when the first voltage signal is lower than the second voltage, the comparison circuit outputs a low level to control the switching device to turn off, and the heated device stops heating. The present invention solves the technical problem of relying on MCU for software control, complex design, and high cost in the prior art. By introducing a hardware control mechanism based on the comparison circuit, the technical effect of realizing over-temperature protection control during the heating process while reducing design and production costs is achieved.

[0065] It should be noted that the order in which the embodiments of the present application are presented is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. Furthermore, the foregoing descriptions of specific embodiments of this specification are provided. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential sequence shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0066] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0067] This specification and drawings are merely illustrative of the present application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Obviously, those skilled in the art may make various modifications and variations to this application without departing from the scope of this application. Thus, this application is intended to include such modifications and variations as fall within the scope of this application and its equivalents.

Claims

1. A heating overtemperature control method, characterized in that: The method is applied to a heating overtemperature control circuit, the heating overtemperature control circuit including a heated device, a comparison circuit, and a switch device, and the method includes: Acquire a first voltage signal representing a current temperature of the heated device; Inputting the first voltage signal into the non-inverting input terminal of the comparison circuit and comparing it with the second voltage signal at the inverting input terminal of the comparison circuit, if the first voltage signal is higher than the second voltage signal, the comparison circuit outputs a high level to control the switching device to turn on, and the heated device continues to be heated; When the first voltage signal is lower than the second voltage, the comparison circuit outputs a low level to control the switch device to be turned off, and the heated device stops heating.

2. The method according to claim 1, wherein The first voltage signal is calculated and outputted through the original temperature measurement voltage of the voltage divider circuit; The voltage divider circuit is composed of a thermistor and a fixed resistor connected in series, and the thermistor is used to measure the temperature of the heated device.

3. The method according to claim 2, wherein The thermistor is a negative temperature coefficient thermistor NTC.

4. The method according to claim 2, wherein The first voltage signal is calculated and outputted through the original temperature measurement voltage of the voltage divider circuit. The calculation formula of the first voltage signal is: Among them, V + is the first voltage signal, representing the voltage at the non-inverting input terminal of the comparison circuit, V1 is the original temperature measurement voltage of the voltage divider circuit, R T is the resistance value of the thermistor, and R1 is the resistance value of the fixed resistor.

5. The method according to claim 2, wherein The comparison circuit further includes a positive feedback resistor, wherein the output terminal of the comparison circuit is connected to the non-inverting input terminal of the comparison circuit through the positive feedback resistor, and the comparison circuit performs hysteresis control through the positive feedback resistor.

6. The method according to claim 5, wherein The calculation formula of the first voltage signal is: Among them, V + is the first voltage signal, representing the voltage at the non-inverting input terminal of the comparison circuit, V1 is the original temperature measurement voltage of the voltage divider circuit, R T is the resistance value of the thermistor, R1 is the resistance value of the fixed resistor, R f is the resistance value of the positive feedback resistor, V out is the output voltage of the comparison circuit, and the output voltage includes a low level or a high level.

7. The method according to claim 5, wherein The positive feedback resistor is an adjustable resistor, and the resistance value of the positive feedback resistor ranges from [100 kΩ to 200 kΩ].

8. The method according to claim 1, wherein The switching device is a semiconductor field effect transistor, and a gate of the semiconductor field effect transistor is connected to the output end of the comparison circuit.

9. The method according to claim 1, wherein The heated device is heated by the heating film; When the switch device is turned on, the heating film is connected to the heating source, and the heated device continues to be heated; When the switch device is closed, the heating film is disconnected from the heating source, and the heated device stops heating.

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