Function expander
By introducing a function expander into traditional control equipment, using high-precision components and electrical isolation design, the problem of insufficient equipment function and expansion is solved, the input and output capabilities and data processing capabilities are improved, signal accuracy and system stability are ensured, and real-time monitoring of environmental parameters is supported.
Patent Information
- Application Number
- CN202422444558.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-10-10
AI Technical Summary
Traditional control equipment has limitations in terms of function and scalability, insufficient output and input loops, insufficient AD detection loops, unable to meet the signal monitoring needs of complex application scenarios, and lacks temperature and humidity detection functions, and cannot respond to environmental changes in a timely manner.
A function extender is designed, including a microcontroller, a semaphore input module, a switching output module, an analog detection module, a communication module and a linear voltage stabilization power module. It adopts high-precision components and electrical isolation design, which increases the input and output capabilities of the equipment and data processing capabilities, and adds a temperature and humidity detection module to monitor environmental parameters in real time.
Without affecting the function of the original equipment, the input and output capabilities and data processing capabilities are significantly improved, the accuracy and reliability of data acquisition are ensured, the anti-interference ability and communication stability of the signal are improved, and the real-time monitoring of environmental parameters is achieved.
Smart Images
Figure CN223140052U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of smart grid, in particular to a function expander. Background Art
[0002] In the fields of power systems and industrial automation, control devices such as reactive power compensation controllers, multifunctional meters, and microcomputer protection devices are crucial. They are not only responsible for accurately detecting analog quantities such as the voltage and current of the power grid, but also need to efficiently process a large number of digital input and output signals, and real-time monitor environmental parameters such as temperature and humidity to ensure the stability of system operation and the efficiency of management. However, with the rapid development of industrial automation and smart grid technologies, the limitations of traditional control devices in terms of function and expandability have become increasingly prominent. Specifically, the number of output and input circuits of the devices is insufficient, making it difficult to meet the wide range of signal monitoring requirements in complex application scenarios. The shortage of its AD (analog-to-digital) detection circuit limits the comprehensiveness and accuracy of data acquisition. In addition, many traditional devices lack temperature and humidity detection functions and cannot respond in a timely manner to the potential impact of environmental changes on device operation. Summary of the Invention
[0003] In view of this, the purpose of the utility model is to provide a function expander with a simple circuit, stable and reliable performance, and easy to expand.
[0004] To achieve the above purpose, the utility model adopts such a function expander, which includes a microcontroller, a signal input module, a digital output module, an analog detection module, a communication module, and a linear regulated power supply module. The output ends of the analog detection module and the signal input module are respectively connected to the input end of the microcontroller. The output end of the microcontroller is connected to the input end of the digital output module. The communication module is electrically connected to the microcontroller. The linear regulated power supply module provides working voltages for the microcontroller, the signal input module, the digital output module, the analog detection module, and the communication module respectively.
[0005] The utility model is further set that the analog detection module includes a line voltage signal processing module, a phase current signal processing module, a temperature detection module, and a humidity detection module. The phase current signal processing module includes four-phase current signal processing circuits with the same circuit composition and four-phase current signal conditioning circuits corresponding to the four-phase current signal processing circuits. The four-phase current signal processing circuits all adopt low-temperature-drift current-limiting resistors and high-precision current transformers. The four-phase current signal conditioning circuits are all composed of resistors and capacitors.
[0006] This utility model is further configured such that the line voltage signal processing module includes four line voltage signal processing circuits with the same circuit composition and four line voltage signal conditioning circuits corresponding to the four line voltage signal processing circuits. Each of the four line voltage signal processing circuits uses high-precision resistors and high-precision voltage transformers, and each of the four line voltage signal conditioning circuits is composed of resistors and capacitors.
[0007] This utility model is further configured such that the temperature detection module includes a temperature sensor interface, a bias resistor, two voltage-dividing resistors, and a filtering capacitor. The two voltage-dividing resistors are connected to the first pin of the temperature sensor interface to form a voltage-dividing circuit for adjusting the output signal of the temperature sensor. The bias resistor is connected between the second pin of the temperature sensor interface and the power supply to provide a stable bias current for the temperature sensor. The filtering capacitor is connected to the output of the voltage-dividing circuit and grounded to filter out high-frequency noise in the signal. The temperature detection module is used to detect the ambient temperature and transmit the processed signal to the microcontroller for processing.
[0008] This utility model is further configured such that the humidity detection module includes a humidity sensor interface, a bias resistor, two voltage-dividing resistors, and a filtering capacitor. The two voltage-dividing resistors are connected to the first pin of the humidity sensor interface to form a voltage-dividing circuit for adjusting the output signal of the humidity sensor. The bias resistor is connected between the second pin of the humidity sensor interface and the power supply to provide a stable bias current for the humidity sensor. The filtering capacitor is connected to the output of the voltage-dividing circuit and grounded to filter out high-frequency noise in the signal. The humidity detection module is used to detect the ambient humidity and transmit the processed signal to the microcontroller for processing.
[0009] This utility model is further configured such that the communication module uses the RS485 communication protocol and is composed of a signal isolation module and a 485 driver module. The signal isolation module is used for electrical isolation between the communication signal and the main circuit, and the 485 driver module is used to convert the digital signal of the microcontroller into an RS485 differential signal and drive the RS485 bus for data transmission.
[0010] This utility model is further configured such that the communication module further includes an isolated power supply output port for providing an independent isolated power supply for RS485 communication.
[0011] This utility model is further configured such that the signal quantity input module includes eight input monitoring circuits with the same circuit composition and a common reference circuit. Each of the eight input monitoring circuits uses optocouplers for electrical isolation of signals, and the common reference circuit uses resistors to provide a common voltage or ground reference point for the eight input monitoring circuits.
[0012] This utility model is further configured such that the digital output module includes twelve output control circuits with the same circuit structure, and all of the twelve output control circuits use optocouplers and relays for isolation control.
[0013] This utility model is further configured such that the linear voltage regulator power supply module includes a main voltage regulator circuit, a first auxiliary voltage regulator circuit, a second auxiliary voltage regulator circuit, a voltage stabilizing circuit, and a grounding circuit. The main voltage regulator circuit is used to provide a stable voltage for the main loads in the circuit. The first auxiliary voltage regulator circuit is used to provide a stable power supply for the analog quantity detection module. The second auxiliary voltage regulator circuit is used to provide a reference voltage for the microcontroller. The voltage stabilizing circuit is used to filter out high-frequency noise and transient fluctuations in the analog power supply voltage. The grounding circuit is used to optimize the grounding loop.
[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: Without affecting the standard functions of the original equipment, this circuit can be added to the equipment through flexible hardware expansion interfaces. It not only retains the basic functions of the original equipment but also significantly improves the input / output capabilities and data processing capabilities. In its analog quantity detection module, the phase current and line voltage signal processing circuits use high-precision components to ensure the accuracy and reliability of data acquisition. At the same time, the addition of the temperature and humidity detection modules enables the equipment to monitor environmental parameters in real time. The signal quantity input module and the digital output module both adopt electrical isolation designs, effectively improving the anti-interference ability of signals and the stability of the system. In addition, the signal conditioning circuit in the analog quantity detection module further filters out high-frequency noise and interference in the signals through the combination of resistors and capacitors, improving the signal-to-noise ratio of the signals. The communication module adopts the RS485 communication protocol, and electrical isolation between the communication signal and the main circuit is achieved through a signal isolation module and a 485 driver module, effectively preventing signal interference and crosstalk. At the same time, the setting of the isolated power output port provides an independent isolated power supply for RS485 communication, further enhancing the stability and reliability of communication. Description of the Drawings
[0015] Figure 1 is the circuit principle block diagram of an embodiment of this utility model.
[0016] Figure 2 is the circuit schematic diagram of the phase current signal processing module of an embodiment of this utility model.
[0017] Figure 3 is the circuit schematic diagram of the line voltage signal processing module of an embodiment of this utility model.
[0018] Figure 4 is the circuit schematic diagram of the temperature detection module and the humidity detection module of an embodiment of this utility model.
[0019] Figure 5This is the circuit schematic diagram of the communication module according to the embodiment of the present utility model.
[0020] Figure 6 This is the circuit schematic diagram of the semaphore input module according to the embodiment of the present utility model.
[0021] Figure 7 This is the circuit schematic diagram of the digital output module according to the embodiment of the present utility model.
[0022] Figure 8 This is the circuit schematic diagram of the linear voltage regulator power supply module according to the embodiment of the present utility model.
[0023] Figure 9 This is the circuit schematic diagram of the microcontroller according to the embodiment of the present utility model. Detailed implementation manners
[0024] As Figures 1-9 shown, the embodiment of the present utility model provides a function expander, which includes a microcontroller, a semaphore input module, a digital output module, an analog detection module, a communication module, and a linear voltage regulator power supply module. The output ends of the analog detection module and the semaphore input module are respectively connected to the input end of the microcontroller. The output end of the microcontroller is connected to the input end of the digital output module. The communication module is electrically connected to the microcontroller. The linear voltage regulator power supply module provides working voltages for the microcontroller, the semaphore input module, the digital output module, the analog detection module, and the communication module respectively.
[0025] As Figure 2 and Figure 9As shown, the analog quantity detection module includes a line voltage signal processing module, a phase current signal processing module, a temperature detection module, and a humidity detection module. The phase current signal processing module includes four-phase current signal processing circuits with the same circuit composition and four-phase current signal conditioning circuits corresponding to the four-phase current signal processing circuits. All four-phase current signal processing circuits use low-temperature-drift current-limiting resistors and high-precision current transformers. All four-phase current signal conditioning circuits are composed of resistors and capacitors. Specifically, taking the first-phase current signal processing circuit as an example, this circuit consists of a high-precision current transformer CT1, a low-temperature-drift current-limiting resistor R60, and a capacitor C7. The first end of the primary side of the high-precision current transformer CT1 is connected to the phase current input point I1_IN, and the second end of the primary side of the high-precision current transformer CT1 is connected to the phase current output point I1_OUT. The first end of the secondary side of the high-precision current transformer CT1 is respectively connected to one end of the low-temperature-drift current-limiting resistor R60, one end of the capacitor C7, and the intermediate signal point I1. The second end of the secondary side of the high-precision current transformer CT1 is respectively connected to the other end of the low-temperature-drift current-limiting resistor R60, the other end of the capacitor C7, and the eighth pin UFF of the microcontroller. Further specifically, corresponding to the first-phase current signal processing circuit is the first-phase current signal conditioning circuit, which consists of a resistor R59 and a capacitor C5. The intermediate signal point I1 is connected to one end of the resistor R59, and the other end of the resistor R59 is respectively connected to one end of the capacitor C5 and the fourteenth pin AIN_I1 of the microcontroller. The other end of the capacitor C5 is connected to the analog ground AGND.
[0026] As Figure 3 and Figure 9As shown, the line voltage signal processing module includes four line voltage signal processing circuits with the same circuit structure and four line voltage signal conditioning circuits corresponding to the four line voltage signal processing circuits. All four line voltage signal processing circuits use high-precision resistors and high-precision voltage transformers, and all four line voltage signal conditioning circuits are composed of resistors and capacitors. Specifically, taking the first line voltage signal processing circuit as an example, this circuit consists of a high-precision voltage transformer PT1, high-precision resistors R38 to R42, and a capacitor C1. The primary side head of the high-precision voltage transformer PT1 is connected to one end of the high-precision resistor R39, the other end of the high-precision resistor R39 is connected to one end of the high-precision resistor R38, the other end of the high-precision resistor R38 is connected to the line voltage input point 1U1, the primary side tail of the high-precision voltage transformer PT1 is connected to one end of the high-precision resistor R42, the other end of the high-precision resistor R42 is connected to one end of the high-precision resistor R41, and the other end of the high-precision resistor R41 is connected to the line voltage input point 1U2. The secondary side head of the high-precision voltage transformer PT1 is respectively connected to the intermediate point U1, one end of the high-precision resistor R40, and one end of the capacitor C1. The secondary side tail of the high-precision voltage transformer PT1 is respectively connected to the eighth pin UFF of the microcontroller, the other end of the high-precision resistor R40, and the other end of the capacitor C1. Further specifically, corresponding to the first line voltage signal processing circuit is the first line voltage signal conditioning circuit, which consists of a resistor R58 and a capacitor C6. The intermediate point U1 is connected to one end of the resistor R58, the other end of the resistor R58 is respectively connected to one end of the capacitor C6 and the twentieth pin AIN_U1 of the microcontroller, and the other end of the capacitor C6 is connected to the analog ground AGND.
[0027] As Figure 4 and Figure 9As shown, the temperature detection module includes a temperature sensor interface, a bias resistor, two voltage-dividing resistors, and a filtering capacitor. The two voltage-dividing resistors are connected to the first pin of the temperature sensor interface to form a voltage-dividing circuit for adjusting the output signal of the temperature sensor. The bias resistor is connected between the second pin of the temperature sensor interface and the power supply to provide a stable bias current for the temperature sensor. The filtering capacitor is connected to the output of the voltage-dividing circuit and grounded to filter out high-frequency noise in the signal. The temperature detection module is used to detect the ambient temperature and transmit the processed signal to the microcontroller for processing. Specifically, the temperature detection module consists of a temperature sensor interface P2, a bias resistor R76, a voltage-dividing resistor R75, a voltage-dividing resistor R77, and a filtering capacitor C36. The temperature sensor interface P2 is used to connect the temperature sensor. The first pin WD2 of the temperature sensor interface P2 is respectively connected to one end of the voltage-dividing resistor R75 and one end of the voltage-dividing resistor R77. The other end of the voltage-dividing resistor R77 is connected to the analog ground AGND. The other end of the voltage-dividing resistor R75 is respectively connected to one end of the filtering capacitor C36 and the twenty-first pin AIN_WD of the microcontroller. The other end of the filtering capacitor C36 is connected to the analog ground AGND. The second pin WD1 of the temperature sensor interface P2 is connected to one end of the bias resistor R76, and the other end of the bias resistor R76 is connected to the power supply AVDD.
[0028] The humidity detection module includes a humidity sensor interface, a bias resistor, two voltage-dividing resistors, and a filtering capacitor. The two voltage-dividing resistors are connected to the first pin of the humidity sensor interface to form a voltage-dividing circuit for adjusting the output signal of the humidity sensor. The bias resistor is connected between the second pin of the humidity sensor interface and the power supply to provide a stable bias current for the humidity sensor. The filtering capacitor is connected to the output of the voltage-dividing circuit and grounded to filter out high-frequency noise in the signal. The humidity detection module is used to detect the ambient humidity and transmit the processed signal to the microcontroller for processing. Specifically, the humidity detection module consists of a humidity sensor interface P4, a bias resistor R79, a voltage-dividing resistor R78, a voltage-dividing resistor R80, and a filtering capacitor C37. The humidity sensor interface P4 is used to connect the humidity sensor. The first pin SD2 of the humidity sensor interface P4 is respectively connected to one end of the voltage-dividing resistor R78 and one end of the voltage-dividing resistor R80. The other end of the voltage-dividing resistor R80 is connected to the analog ground AGND. The other end of the voltage-dividing resistor R78 is respectively connected to one end of the filtering capacitor C37 and the twenty-second pin AIN_SD of the microcontroller. The other end of the filtering capacitor C37 is connected to the analog ground AGND. The second pin SD1 of the humidity sensor interface P4 is connected to one end of the bias resistor R79, and the other end of the bias resistor R79 is connected to the power supply AVDD.
[0029] As Figure 5 and Figure 9As shown, the communication module adopts the RS485 communication protocol and consists of a signal isolation module and a 485 driver module. The signal isolation module is used for the electrical isolation between the communication signal and the main circuit, and the 485 driver module is used to convert the digital signal of the microcontroller into an RS485 differential signal and drive the RS485 bus for data transmission. The communication module also includes an isolated power output port for providing an independent isolated power supply for RS485 communication. Specifically, the signal isolation module is composed of a signal isolation chip U3 with the model number π122U31, and the 485 driver module is composed of a 485 driver chip with the model number MAX13085EESA. Further specifically, the first pin of the isolated power output port B1 is connected to the power supply voltage V5, the second pin of the isolated power output port B1 is grounded, the third pin of the isolated power output port B1 is connected to the power supply voltage V485, and the fourth pin of the isolated power output port B1 is connected to the reference ground GND_485.
[0030] As Figure 6 and Figure 9 shown, the semaphore input module includes eight-way input monitoring circuits with the same circuit composition and a common reference circuit. All the eight-way input monitoring circuits use optocouplers for electrical isolation of signals, and the common reference circuit uses resistors to provide a common voltage or ground reference point for the eight-way input monitoring circuits. Specifically, taking the first-way input monitoring circuit as an example, this circuit consists of resistor R7, resistor R11, resistor R15, and optocoupler O7. The positive pole of the light-emitting end of optocoupler O7 is respectively connected to one end of resistor R11 and one end of resistor R15. The other end of resistor R11 is connected to the common input reference point DI_COM. The negative pole of the light-emitting end of optocoupler O7 is respectively connected to the other end of resistor R15 and the input signal DI_1. The collector of the light-receiving end of optocoupler O7 is respectively connected to the fifty-third pin Sign_1 end of the microcontroller and one end of resistor R7. The other end of resistor R7 is connected to the power supply V3.3. The emitter of the light-receiving end of optocoupler O7 is grounded. Further specifically, the common reference circuit consists of resistor R37. One end of resistor R37 is connected to the common input reference point DI_COM, and the other end is connected to the common reference power supply voltage V12.
[0031] As Figure 7 and Figure 9As shown in the figure, the digital output module includes twelve output control circuits with the same circuit structure. All the twelve output control circuits use optocouplers and relays for isolation control. Specifically, taking the first output control circuit as an example, this circuit consists of a resistor R1, an optocoupler O1, a diode D1, and a relay K1. The positive pole of the light-emitting end of the optocoupler O1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the power supply V3.3, the negative pole of the light-emitting end of the optocoupler O1 is connected to the 41st pin RLY1 of the microcontroller. The collector of the light-receiving end of the optocoupler O1 is connected to the power supply V12, and the emitter of the light-receiving end of the optocoupler O1 is respectively connected to the negative pole of the diode D1 and the 3rd pin of the relay K1. The 4th pin of the relay K1 and the positive pole of the diode D1 are both grounded. The 1st pin of the relay K1 is connected to the output terminal OUT1, and the 2nd pin of the relay K1 is connected to the common terminal OUT_COM.
[0032] As Figure 8 and Figure 9 As shown in the figure, the linear voltage regulator power supply module includes a main voltage regulator circuit, a first auxiliary voltage regulator circuit, a second auxiliary voltage regulator circuit, a voltage regulator circuit, and a grounding circuit. The main voltage regulator circuit is used to provide a stable voltage for the main loads in the circuit. The first auxiliary voltage regulator circuit is used to provide a stable power supply for the analog quantity detection module. The second auxiliary voltage regulator circuit is used to provide a reference voltage for the microcontroller. The voltage regulator circuit is used to filter out the high-frequency noise and transient fluctuations in the analog power supply voltage. The grounding circuit is used to optimize the grounding loop. Specifically, the main voltage regulator circuit consists of a three-terminal voltage regulator U1, filter capacitors C11 - C12, and electrolytic capacitors C9 - C10. The 3rd pin Vin of the three-terminal voltage regulator U1 is respectively connected to one end of the filter capacitor C11 and the positive pole of the electrolytic capacitor C9, and also receives the input voltage V5. The 2nd pin Vout of the three-terminal voltage regulator U1 is respectively connected to one end of the filter capacitor C12 and the positive pole of the electrolytic capacitor C10, and also outputs a stable 3.3V voltage. The 1st pin GND of the three-terminal voltage regulator U1, the negative pole of the electrolytic capacitor C9, the other end of the filter capacitor C11, the other end of the filter capacitor C12, and the negative pole of the electrolytic capacitor C10 are all grounded.
[0033] The first auxiliary voltage regulator circuit consists of a three-terminal voltage regulator V1, filter capacitors C20, C24, and an electrolytic capacitor C22. The 3rd pin Vin of the three-terminal voltage regulator V1 is connected to one end of the filter capacitor C20, and also receives the input voltage V5_2. The other end of the filter capacitor C20 is grounded. The 2nd pin Vout of the three-terminal voltage regulator V1 is respectively connected to the positive pole of the electrolytic capacitor C22 and one end of the filter capacitor C24, and also outputs a stable AVDD voltage. The negative pole of the electrolytic capacitor C22 and the other end of the filter capacitor C24 are both connected to the analog ground AGND. The 1st pin GND of the three-terminal voltage regulator V1 is connected to the analog ground AGND.
[0034] The second auxiliary voltage stabilizing circuit consists of a three-terminal voltage regulator V2, a filtering capacitor C21, a filtering capacitor C25, an electrolytic capacitor C23, a resistor R68, and a resistor R73. The third pin Vin of the three-terminal voltage regulator V2 is connected to one end of the filtering capacitor C21 and also receives the input voltage AVDD. The other end of the filtering capacitor C21 is connected to the analog ground AGND. The second pin Vout of the three-terminal voltage regulator V2 is respectively connected to one end of the resistor R68, the positive electrode of the electrolytic capacitor C23, the eighth pin UFF of the microcontroller, and one end of the filtering capacitor C25. The negative electrode of the electrolytic capacitor C23 and the other end of the filtering capacitor C25 are both connected to the analog ground AGND. The first pin GND of the three-terminal voltage regulator V2 is respectively connected to the other end of the resistor R68 and one end of the resistor R73, and the other end of the resistor R73 is connected to the analog ground AGND.
[0035] The voltage stabilizing circuit consists of a filtering capacitor C33 and an electrolytic capacitor C35. The filtering capacitor C33 and the electrolytic capacitor C35 are connected in parallel between AVDD and the analog ground AGND to filter out high-frequency noise and transient fluctuations on AVDD. The grounding circuit consists of a resistor R74. One end of the resistor R74 is connected to the analog ground AGND, and the other end is grounded. Further specifically, a switching power supply interface P1 is also included.
[0036] As Figure 9 shown, the microcontroller consists of a main control chip U2 with the model HC32F460KETA.
[0037] Of course, in addition to the above embodiments, the present utility model can also have many other embodiments. Without departing from the essential technical solution content of the present utility model, those skilled in the art can make various corresponding changes and deformations according to the present utility model. And if these changes or deformations are equivalent to the technical solutions in this patent, then these corresponding changes and deformations should all fall within the protection scope of the appended claims of the present utility model, and this utility model creation meets the actual R & D capabilities and resource conditions of the applicant.
Claims
1. A function expander, characterized in that: It includes a microcontroller, a semaphore input module, a digital output module, an analog detection module, a communication module, and a linear voltage regulator power supply module. The output ends of the analog detection module and the semaphore input module are respectively connected to the input end of the microcontroller. The output end of the microcontroller is connected to the input end of the digital output module. The communication module is electrically connected to the microcontroller. The linear voltage regulator power supply module provides working voltages for the microcontroller, the semaphore input module, the digital output module, the analog detection module, and the communication module respectively.
2. The function expander according to claim 1, characterized in that: The analog detection module includes a line voltage signal processing module, a phase current signal processing module, a temperature detection module, and a humidity detection module. The phase current signal processing module includes four-phase current signal processing circuits with the same circuit composition and four-phase current signal conditioning circuits corresponding to the four-phase current signal processing circuits. All the four-phase current signal processing circuits adopt low-temperature-drift current-limiting resistors and high-precision current transformers. All the four-phase current signal conditioning circuits are composed of resistors and capacitors.
3. The functional expander according to claim 2, characterized in that: The line voltage signal processing module includes four-line voltage signal processing circuits with the same circuit composition and four-line voltage signal conditioning circuits corresponding to the four-line voltage signal processing circuits. All the four-line voltage signal processing circuits adopt high-precision resistors and high-precision voltage transformers. All the four-line voltage signal conditioning circuits are composed of resistors and capacitors.
4. The function expander according to claim 2, wherein: The temperature detection module includes a temperature sensor interface, a bias resistor, two voltage-dividing resistors, and a filter capacitor. The two voltage-dividing resistors are connected to the first pin of the temperature sensor interface to form a voltage-dividing circuit for adjusting the output signal of the temperature sensor. The bias resistor is connected between the second pin of the temperature sensor interface and the power supply to provide a stable bias current for the temperature sensor. The filter capacitor is connected to the output of the voltage-dividing circuit and grounded to filter out high-frequency noise in the signal. The temperature detection module is used to detect the ambient temperature and transmit the processed signal to the microcontroller for processing.
5. The function expander according to claim 2, wherein: The humidity detection module includes a humidity sensor interface, a bias resistor, two voltage-dividing resistors, and a filter capacitor. The two voltage-dividing resistors are connected to the first pin of the humidity sensor interface to form a voltage-dividing circuit for adjusting the output signal of the humidity sensor. The bias resistor is connected between the second pin of the humidity sensor interface and the power supply to provide a stable bias current for the humidity sensor. The filter capacitor is connected to the output of the voltage-dividing circuit and grounded to filter out high-frequency noise in the signal. The humidity detection module is used to detect the ambient humidity and transmit the processed signal to the microcontroller for processing.
6. The function expander according to claim 1, characterized in that: The communication module adopts the RS485 communication protocol and is composed of a signal isolation module and a 485 driver module. The signal isolation module is used for electrical isolation between the communication signal and the main circuit. The 485 driver module is used to convert the digital signal of the microcontroller into an RS485 differential signal and drive the RS485 bus for data transmission.
7. The function expander according to claim 6, characterized in that: The communication module further includes an isolated power output port for providing an independent isolated power supply for RS485 communication.
8. The function expander according to claim 1, wherein: The signal quantity input module includes an eight-way input monitoring circuit and a common reference circuit with the same circuit configuration. All the eight-way input monitoring circuits use optocouplers for electrical isolation of signals, and the common reference circuit uses resistors to provide a common voltage or ground reference point for the eight-way input monitoring circuits.
9. The function expander according to claim 1, characterized in that: The digital quantity output module includes a twelve-way output control circuit with the same circuit configuration. All the twelve-way output control circuits use optocouplers and relays for isolation control.
10. The function expander according to claim 1, characterized in that: The linear voltage regulator power supply module includes a main voltage regulator circuit, a first auxiliary voltage regulator circuit, a second auxiliary voltage regulator circuit, a voltage stabilizing circuit and a grounding circuit. The main voltage regulator circuit is used to provide a stable voltage for the main loads in the circuit. The first auxiliary voltage regulator circuit is used to provide a stable power supply for the analog quantity detection module. The second auxiliary voltage regulator circuit is used to provide a reference voltage for the microcontroller. The voltage stabilizing circuit is used to filter out high-frequency noise and transient fluctuations in the analog power supply voltage. The grounding circuit is used to optimize the grounding loop.