Multi-channel temperature controller

Abstract

The utility model discloses a multi-channel temperature controller, which comprises a main control module, a communication module, a dial switch module, a coding module, a power supply module, an eight-channel temperature data acquisition module, an eight-channel control voltage output module and a cold end temperature monitoring module, the dial switch module is used for setting the address of the temperature control module; the encoder module is used for setting the baud rate of the communication module; the power supply module is used for supplying power to the main control module, the dial switch module, the encoding module, the temperature data acquisition module and the cold end temperature monitoring module. Each temperature data acquisition module is connected with each control voltage output module, the temperature data acquisition modules are used for acquiring temperature data and outputting the temperature data to the main control module, and the control voltage output modules are used for outputting stable voltage; the cold end temperature monitoring module is used for collecting the temperature of the cold end in real time. The temperature control system is good in temperature control effect and high in stability and reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature controllers, in particular to a multi-channel temperature controller. Background Art

[0002] At present, countries around the world are paying more and more attention to air pollution and energy issues. It is a general trend to promote electric vehicles to reduce exhaust emissions from fuel vehicles. With the improvement of people's quality of life and environmental awareness, the requirements for paper-based gift boxes and fast food boxes are getting higher and higher. As a result, the requirements for temperature data collection of paper machines and the safety and reliability of products are also getting higher and higher. Among them, the accuracy of temperature data collection is more demanding. If the temperature is too low, the paper box is easy to wrinkle and the molding quality is poor. If the temperature is too high, the paper box is easy to darken and blacken.

[0003] Existing temperature controllers generally include a temperature acquisition circuit, a control circuit and an output circuit. Each control circuit corresponds to a temperature acquisition circuit one-to-one. The temperature acquisition circuit acquires the corresponding temperature. The control circuit outputs a control signal to the output circuit according to the temperature control. The output circuit outputs the control signal to control the corresponding temperature.

[0004] However, the temperature acquisition circuits of the above-mentioned temperature controller correspond one to one with the temperature acquisition circuits, and the temperature acquisition circuits are single; when controlling multiple temperatures, the cost is too high, the control effect is poor, and the overall stability and reliability of the controller are poor. Utility Model Content

[0005] The purpose of the embodiment of the utility model is to provide a multi-channel temperature controller to solve the problems of high cost, poor control effect, poor stability and reliability of the existing temperature controller.

[0006] In order to solve the above technical problems, the embodiment of the utility model provides a multi-channel temperature controller, including: a main control module, a communication module, a dip switch module, an encoding module, a power supply module, an 8-channel temperature data acquisition module, an 8-channel control voltage output module and a cold end temperature monitoring module;

[0007] The main control module is electrically connected to the DIP switch module, the encoding module, the power supply module, the 8-channel temperature data acquisition module and the cold end temperature monitoring module respectively through the communication module;

[0008] The dip switch module is used to set the address of the temperature control module; the encoding module is used to set the baud rate of the communication module; the power supply module is used to supply power to the main control module, the dip switch module, the encoding module, the power supply module, the temperature data acquisition module and the cold end temperature monitoring module respectively; each of the temperature data acquisition modules is connected to each of the control voltage output modules respectively, the temperature data acquisition module is used to collect temperature data and output it to the main control module, and the control voltage output module is used to output a stable voltage; the cold end temperature monitoring module is used to collect the temperature of the cold end in real time.

[0009] Preferably, the main control module is a GD32F103RBT6 or STM32F103RBT6 processor.

[0010] Preferably, the communication module is an RS485 communication protocol.

[0011] Preferably, the dip switch module includes 4 switches, a control end of each switch is grounded, and an output end of each switch is used to set the address of the temperature control module.

[0012] Preferably, the encoding module is a BCD encoder.

[0013] Preferably, the temperature data acquisition module includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first diode, a second diode, a third diode, a fourth diode, a fifth resistor, a sixth resistor, a sixth capacitor, a signal conversion chip, a seventh resistor, an eighth resistor, a ninth resistor, a seventh capacitor, an eighth capacitor and a ninth capacitor;

[0014] The first end of the first resistor is grounded, the second end of the first resistor is respectively connected to the signal input end and the first end of the second resistor, the second end of the second resistor is respectively connected to the first end of the first capacitor and the first end of the second capacitor, and the second end of the first capacitor is grounded;

[0015] The first end of the third resistor is used to connect to the power supply, the second end of the third resistor is respectively connected to the signal input end and the first end of the fourth resistor, the second end of the fourth resistor is respectively connected to the second end of the second capacitor and the first end of the third capacitor, and the second end of the third capacitor is grounded;

[0016] The second end of the second capacitor is also connected to the first end of the sixth resistor, the cathode of the first diode and the anode of the second diode respectively, the second end of the sixth resistor is connected to the pin 4 of the signal conversion chip, the anode of the first diode is grounded, the cathode of the second diode is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the fifth capacitor and grounded, the second end of the fifth capacitor is connected to the cathode of the fourth diode, the anode of the fourth diode is connected to the first end of the first capacitor, the cathode of the third diode and the pin 3 of the signal conversion chip respectively, and the anode of the third diode is grounded; the pin 8 of the signal conversion chip is set to be suspended;

[0017] The first end of the sixth capacitor is used to connect the bias voltage and the pin 1 of the signal conversion chip, the pin 2 of the signal conversion chip is respectively connected to the first end of the first capacitor, the first end of the eighth capacitor and the first end of the ninth capacitor and is grounded, the pin 7 of the signal conversion chip is respectively connected to the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth capacitor and the first end of the ninth resistor, and the second end of the ninth resistor is used to connect to the power supply;

[0018] Pin 5 of the signal conversion chip is connected to the first end of the seventh resistor, and pin 6 of the signal conversion chip is connected to the first end of the eighth resistor; the second end of the seventh resistor and the second end of the eighth resistor are connected to the main control module.

[0019] Preferably, the signal conversion chip is a CS1237 chip.

[0020] Preferably, the control voltage output module comprises: a tenth resistor, an eleventh resistor, an optocoupler, a fifth diode and a triode;

[0021] The first end of the tenth resistor is used to connect to the main control module, the second end of the tenth resistor is connected to pin 2 of the optocoupler, pin 1 of the optocoupler is used to connect to the power supply, pin 3 of the optocoupler is respectively connected to the first end of the eleventh resistor and the base of the transistor, pin 4 of the optocoupler is respectively connected to the collector of the transistor and the positive electrode of the fifth diode and grounded; the second end of the eleventh resistor is respectively connected to the emitter base of the transistor and the negative electrode of the fifth diode, and is used to output signals.

[0022] Preferably, the model of the optocoupler is an EL357 chip.

[0023] Preferably, the cold end temperature monitoring module comprises: a twelfth resistor, a thirteenth resistor, a tenth capacitor, an eleventh capacitor and an operational amplifier;

[0024] The first end of the twelfth resistor is connected to the first end of the tenth capacitor and is grounded, the second end of the twelfth resistor is respectively connected to the second end of the tenth capacitor, the positive input end of the operational amplifier and the first end of the thirteenth resistor, the second end of the thirteenth resistor is used to connect to a voltage-stabilized power supply, the negative input end of the operational amplifier is connected to the output end of the operational amplifier, the output end of the operational amplifier is connected to the main control module, the first end of the eleventh capacitor is connected to the operational amplifier and a power supply, and the second end of the eleventh capacitor is grounded.

[0025] Compared with the prior art, the multi-channel temperature controller in the utility model is electrically connected to the dip switch module, the encoding module, the power supply module, the 8-channel temperature data acquisition module and the cold end temperature monitoring module through the main control module and the communication module; the dip switch module is used to set the address of the temperature control module; the encoder module is used to set the baud rate of the communication module; the power supply module is used to supply power to the main control module, the dip switch module, the encoding module, the power supply module, the temperature data acquisition module and the cold end temperature monitoring module respectively; each temperature data acquisition module is connected to each control voltage output module respectively, the temperature data acquisition module is used to collect temperature data and output it to the main control module, and the control voltage output module is used to output a stable voltage; the cold end temperature monitoring module is used to collect the temperature of the cold end in real time; so that the temperature controller can be applied to 8-channel temperature data acquisition using thermocouples, with good temperature control effect, low manufacturing cost and wide application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, 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 utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work, among which:

[0027] Figure 1 A module diagram of a multi-channel temperature controller provided by an embodiment of the utility model;

[0028] Figure 2 A circuit diagram of a main control module provided by an embodiment of the utility model;

[0029] Figure 3 A circuit diagram of a communication module provided in an embodiment of the utility model;

[0030] Figure 4 A circuit diagram of a DIP switch module provided in an embodiment of the utility model;

[0031] Figure 5A circuit diagram of an encoding module provided in an embodiment of the utility model;

[0032] Figure 6 A circuit diagram of a power supply module provided in an embodiment of the utility model;

[0033] Figure 7 A circuit diagram of a temperature data acquisition module provided by an embodiment of the utility model;

[0034] Figure 8 A circuit diagram of a control voltage output module provided by an embodiment of the utility model;

[0035] Fig. 9 A circuit diagram of a cold-end temperature monitoring module provided in an embodiment of the utility model.

[0036] Among them, 100, multi-channel temperature controller, 1, main control module, 2, communication module, 3, dip switch module, 4, encoding module, 5, power supply module, 6, temperature data acquisition module, 7, control voltage output module, 8, cold end temperature monitoring module. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Please refer to the attached Figure 1-Figure 9 As shown, an embodiment of the utility model provides a multi-channel temperature controller 100, including: a main control module 1, a communication module 2, a dip switch module 3, an encoding module 4, a power supply module 5, an 8-channel temperature data acquisition module 6, an 8-channel control voltage output module 7 and a cold end temperature monitoring module 8.

[0039] The main control module 1 is electrically connected to the DIP switch module 3 , the encoding module 4 , the power supply module 5 , the 8-channel temperature data acquisition module 6 and the cold end temperature monitoring module 8 respectively through the communication module 2 .

[0040] The dip switch module 3 is used to set the address (ID) of the temperature control module; the encoder module is used to set the baud rate of the communication module 2; the power supply module 5 is used to supply power to the main control module 1, the dip switch module 3, the encoder module 4, the power supply module 5, the temperature data acquisition module 6 and the cold end temperature monitoring module 8; each temperature data acquisition module 6 is connected to each control voltage output module 7, the temperature data acquisition module 6 is used to collect temperature data and output it to the main control module 1, and the control voltage output module 7 is used to output a stable voltage; the cold end temperature monitoring module 8 is used to collect the temperature of the cold end in real time. The temperature controller can be applied to 8-way temperature data acquisition using thermocouples, with good temperature control effect, low manufacturing cost and wide application.

[0041] In this embodiment, the main control module 1 is a GD32F103RBT6 or STM32F103RBT6 processor. The processor is GD32F103RBT6 / STM32F103RBT6, which is responsible for processing the temperature signal collected by the CS1237 chip and calculating the output to control the action of the PLC amplifier.

[0042] In this embodiment, the communication module 2 is an RS485 communication protocol. The circuit is used to communicate with the host computer, and the communication adopts the modbus protocol.

[0043] In this embodiment, the dip switch module 3 includes four switches, a control end of each switch is grounded, and an output end of each switch is used to set the address of the temperature control module.

[0044] In this embodiment, the encoding module 4 is a BCD encoder.

[0045] In this embodiment, the temperature data acquisition module 6 includes: a first resistor R17, a second resistor R18, a third resistor R24, a fourth resistor R23, a first capacitor C30, a second capacitor C32, a third capacitor C33, a fourth capacitor C23, a fifth capacitor C24, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth resistor R19, a sixth resistor R21, a sixth capacitor C28, a signal conversion chip U6, a seventh resistor R20, an eighth resistor R22, a ninth resistor R16, a seventh capacitor C27, an eighth capacitor C29 and a ninth capacitor C31;

[0046] A first end of the first resistor R17 is grounded, a second end of the first resistor R17 is respectively connected to a signal input end and a first end of the second resistor R18, a second end of the second resistor R18 is respectively connected to a first end of the first capacitor C30 and a first end of the second capacitor C32, and a second end of the first capacitor C30 is grounded;

[0047] The first end of the third resistor R24 ​​is used to connect to the power supply, the second end of the third resistor R24 ​​is respectively connected to the signal input end and the first end of the fourth resistor R23, the second end of the fourth resistor R23 is respectively connected to the second end of the second capacitor C32 and the first end of the third capacitor C33, and the second end of the third capacitor C33 is grounded;

[0048] The second end of the second capacitor C32 is also connected to the first end of the sixth resistor R21, the cathode of the first diode D1 and the anode of the second diode D2 respectively, the second end of the sixth resistor R21 is connected to the pin 4 of the signal conversion chip U6, the anode of the first diode D1 is grounded, the cathode of the second diode D2 is connected to the first end of the fourth capacitor C23, the second end of the fourth capacitor C23 is connected to the first end of the fifth capacitor C24 and grounded, the second end of the fifth capacitor C24 is connected to the cathode of the fourth diode D4, the anode of the fourth diode D4 is connected to the first end of the first capacitor C30, the cathode of the third diode D3 and the pin 3 of the signal conversion chip U6 respectively, and the anode of the third diode D3 is grounded; the pin 8 of the signal conversion chip U6 is set to be suspended;

[0049] The first end of the sixth capacitor C28 is used to connect the bias voltage and the pin 1 of the signal conversion chip U6, the pin 2 of the signal conversion chip U6 is respectively connected to the first end of the first capacitor C30, the first end of the eighth capacitor C29 and the first end of the ninth capacitor C31 and grounded, the pin 7 of the signal conversion chip U6 is respectively connected to the second end of the seventh capacitor C27, the second end of the eighth capacitor C29, the second end of the ninth capacitor C31 and the first end of the ninth resistor R16, and the second end of the ninth resistor R16 is used to connect to the power supply;

[0050] Pin 5 of the signal conversion chip U6 is connected to the first end of the seventh resistor R20, and pin 6 of the signal conversion chip U6 is connected to the first end of the eighth resistor R22; the second end of the seventh resistor R20 and the second end of the eighth resistor R22 are connected to the main control module 1.

[0051] Among them, TC_I N_N_1 and TC_I N_P_1 are the two input terminals of the thermocouple. The temperature data collected by the thermocouple enters from here, and after filtering, enters from pins 3 and 4 of CS1237. CS1237 converts the thermocouple signal into a digital signal, and then outputs it from pin 6 and sends it to the MCU.

[0052] In this embodiment, the signal conversion chip is a CS1237 chip. Specifically, the temperature data acquisition module 6 is an AD conversion circuit based on CS1237 and its peripheral circuits, and the output end of the CS1237 chip is connected to the input end of the main control module 1.

[0053] In this embodiment, the control voltage output module 7 includes: a tenth resistor R94, an eleventh resistor R91, an optical coupler U15, a fifth diode D21 and a transistor Q2;

[0054] The first end of the tenth resistor R94 is used to connect to the main control module 1, the second end of the tenth resistor R94 is connected to pin 2 of the optocoupler U15, the pin 1 of the optocoupler U15 is used to connect to the power supply, the pin 3 of the optocoupler U15 is respectively connected to the first end of the eleventh resistor R91 and the base of the transistor Q2, the pin 4 of the optocoupler U15 is respectively connected to the collector of the transistor Q2 and the positive electrode of the fifth diode D21 and grounded; the second end of the eleventh resistor R91 is respectively connected to the emitter base of the transistor Q2 and the negative electrode of the fifth diode D21, and is used to output signals.

[0055] Among them, each output signal TC_OUT is connected to a solid-state relay or a PLC amplifier, and the output PWM signal is used to control the on and off of the relay or PLC, and then control the heating of the heating rod.

[0056] In this embodiment, the model of the optocoupler U15 is an EL357 chip.

[0057] In this embodiment, the cold end temperature monitoring module 8 includes: a twelfth resistor R12, a tenth resistor R5, a tenth capacitor C98, an eleventh capacitor C97 and an operational amplifier U14;

[0058] The first end of the twelfth resistor R12 is connected to the first end of the tenth capacitor C98 and is grounded, the second end of the twelfth resistor R12 is respectively connected to the second end of the tenth capacitor C98, the positive input end of the operational amplifier U14 and the first end of the tenth resistor R5, the second end of the tenth resistor R5 is used to connect to a regulated power supply, the negative input end of the operational amplifier U14 is connected to the output end of the operational amplifier U14, the output end of the operational amplifier U14 is connected to the main control module 1, the first end of the eleventh capacitor C97 is connected to the operational amplifier U14 and is used for power supply, and the second end of the eleventh capacitor C97 is grounded.

[0059] Among them, the cold end temperature detection adopts NTC detection, and NTC adopts high-precision NTC.

[0060] Specifically, when designing, the input end of the thermocouple is close to the input end, and its output is used as the temperature of the cold end and sent to the MCU, where it is mixed with the measured value of the working end, and then the actual temperature of the thermocouple working end is obtained by looking up the table. The control signal output by the MCU enters from pin 2 of the optocoupler EL357 and is output from TC_OUT to the PLC amplifier to control the heating.

[0061] Specifically, the temperature controller includes a main control circuit based on GD32 / STM32, a temperature data conversion circuit based on CS1237 (including a cold end compensation circuit and a working section detection circuit), and a signal input conditioning circuit based on a K-type thermocouple. The output of the K-type thermocouple is connected to the CS1237 after signal conditioning and protection control; the output end of the CS1237 is connected to the MCU, and the CS1237 converts the signal collected by the K-type thermocouple and sends it to the MCU. Another CS1237 collects the ambient temperature as the cold end temperature and then sends it to the MCU. The MCU obtains the current temperature value by converting the temperature data detected by the two CS1237s through a table lookup, and then compares the value with the target value, and then uses the difference to adjust the output of the PID. The output of the MCU is connected to the output control circuit to control the heating current, thereby achieving the purpose of temperature control. The CS1237 is a 24-bit AD converter with low price and high precision. Through its cooperation with the MCU and the algorithm, the accuracy of temperature acquisition is effectively improved. The input signal conditioning circuit effectively provides system stability and reliability through two BAT54S-based protection circuits.

[0062] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0063] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A multi-channel temperature controller, characterized in that: include: Main control module, communication module, DIP switch module, encoding module, power supply module, 8-channel temperature data acquisition module, 8-channel control voltage output module and cold end temperature monitoring module; The main control module is electrically connected to the DIP switch module, the encoding module, the power supply module, the 8-channel temperature data acquisition module and the cold end temperature monitoring module respectively through the communication module; The dip switch module is used to set the address of the temperature control module; the encoding module is used to set the baud rate of the communication module; the power supply module is used to supply power to the main control module, the dip switch module, the encoding module, the power supply module, the temperature data acquisition module and the cold end temperature monitoring module respectively; each of the temperature data acquisition modules is connected to each of the control voltage output modules respectively, the temperature data acquisition module is used to collect temperature data and output it to the main control module, and the control voltage output module is used to output a stable voltage; the cold end temperature monitoring module is used to collect the temperature of the cold end in real time.

2. The multi-channel temperature controller according to claim 1, characterized in that: The main control module is a GD32F103RBT6 or STM32F103RBT6 processor.

3. The multi-channel temperature controller according to claim 1, characterized in that: The communication module adopts RS485 communication protocol.

4. The multi-channel temperature controller according to claim 1, characterized in that: The dip switch module includes 4 switches, a control end of each switch is grounded, and an output end of each switch is used to set the address of the temperature control module.

5. The multi-channel temperature controller according to claim 1, characterized in that: The encoding module is a BCD encoder.

6. The multi-channel temperature controller according to claim 1, characterized in that: The temperature data acquisition module includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first diode, a second diode, a third diode, a fourth diode, a fifth resistor, a sixth resistor, a sixth capacitor, a signal conversion chip, a seventh resistor, an eighth resistor, a ninth resistor, a seventh capacitor, an eighth capacitor and a ninth capacitor; The first end of the first resistor is grounded, the second end of the first resistor is respectively connected to the signal input end and the first end of the second resistor, the second end of the second resistor is respectively connected to the first end of the first capacitor and the first end of the second capacitor, and the second end of the first capacitor is grounded; The first end of the third resistor is used to connect to the power supply, the second end of the third resistor is respectively connected to the signal input end and the first end of the fourth resistor, the second end of the fourth resistor is respectively connected to the second end of the second capacitor and the first end of the third capacitor, and the second end of the third capacitor is grounded; The second end of the second capacitor is also connected to the first end of the sixth resistor, the cathode of the first diode and the anode of the second diode respectively, the second end of the sixth resistor is connected to the pin 4 of the signal conversion chip, the anode of the first diode is grounded, the cathode of the second diode is connected to the first end of the fourth capacitor, the second end of the fourth capacitor is connected to the first end of the fifth capacitor and grounded, the second end of the fifth capacitor is connected to the cathode of the fourth diode, the anode of the fourth diode is connected to the first end of the first capacitor, the cathode of the third diode and the pin 3 of the signal conversion chip respectively, and the anode of the third diode is grounded; the pin 8 of the signal conversion chip is set to be suspended; The first end of the sixth capacitor is used to connect the bias voltage and the pin 1 of the signal conversion chip, the pin 2 of the signal conversion chip is respectively connected to the first end of the first capacitor, the first end of the eighth capacitor and the first end of the ninth capacitor and is grounded, the pin 7 of the signal conversion chip is respectively connected to the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth capacitor and the first end of the ninth resistor, and the second end of the ninth resistor is used to connect to the power supply; Pin 5 of the signal conversion chip is connected to the first end of the seventh resistor, and pin 6 of the signal conversion chip is connected to the first end of the eighth resistor; the second end of the seventh resistor and the second end of the eighth resistor are connected to the main control module.

7. The multi-channel temperature controller according to claim 6, characterized in that: The model of the signal conversion chip is CS1237 chip.

8. The multi-channel temperature controller according to claim 1, characterized in that: The control voltage output module includes: a tenth resistor, an eleventh resistor, an optocoupler, a fifth diode and a triode; The first end of the tenth resistor is used to connect to the main control module, the second end of the tenth resistor is connected to pin 2 of the optocoupler, pin 1 of the optocoupler is used to connect to the power supply, pin 3 of the optocoupler is respectively connected to the first end of the eleventh resistor and the base of the transistor, pin 4 of the optocoupler is respectively connected to the collector of the transistor and the positive electrode of the fifth diode and grounded; the second end of the eleventh resistor is respectively connected to the emitter base of the transistor and the negative electrode of the fifth diode, and is used to output signals.

9. The multi-channel temperature controller according to claim 8, characterized in that: The model of the optocoupler is EL357 chip.

10. The multi-channel temperature controller according to claim 1, characterized in that: The cold end temperature monitoring module comprises: a twelfth resistor, a thirteenth resistor, a tenth capacitor, an eleventh capacitor and an operational amplifier; The first end of the twelfth resistor is connected to the first end of the tenth capacitor and is grounded, the second end of the twelfth resistor is respectively connected to the second end of the tenth capacitor, the positive input end of the operational amplifier and the first end of the thirteenth resistor, the second end of the thirteenth resistor is used to connect to a voltage-stabilized power supply, the negative input end of the operational amplifier is connected to the output end of the operational amplifier, the output end of the operational amplifier is connected to the main control module, the first end of the eleventh capacitor is connected to the operational amplifier and a power supply, and the second end of the eleventh capacitor is grounded.

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