A control circuit for an oil fume purifier

Abstract

The utility model discloses a kind of oil fume purifier control circuit, the circuit includes: sensor module, is connected with each sensor by acquisition bus, simultaneously the sensor module is also connected with controller;Wireless module is connected with the controller, for transmitting data or receiving external instruction to external server;Display module is connected with the controller, for showing the data collected by each sensor;Power module is respectively connected with sensor module, wireless module and display module power supply, can make oil fume purifier can directly monitor collection working environment parameter, to make external server can directly regulate and control oil fume purifier.

Description

Technical Field

[0001] This utility model belongs to the technical field of oil fume purifiers, specifically relating to a control circuit for an oil fume purifier. Background Technology

[0002] Fume purifiers, also known as integrated fume purification machines, are primarily used in the catering industry. The fumes produced in this sector contain a large amount of particulate matter and harmful gases, such as PM2.5, VOCs (volatile organic compounds), and polycyclic aromatic hydrocarbons (PAHs). These pollutants not only affect air quality but also pose a threat to residents' health. Integrated fume purification machines effectively remove particulate matter and odors from fumes through electrostatic purification technology, UV photolysis technology, and activated carbon adsorption technology, achieving ultra-low fume emissions with concentrations far below national standards.

[0003] Most integrated fume purification control systems on the market can only achieve basic on / off control. They cannot systematically collect and monitor data such as fume concentration, wind speed and pressure, ozone, and noise. They rely solely on various external data acquisition devices. First, this results in a lack of system integration and low data silos. Because each sensor is an independent system, the data is not open or readable, creating isolated data silos that hinder comprehensive data utilization and intelligent analysis and control. Second, data acquisition is difficult and unreliable. Relying on external sensor systems necessitates reliance on their accuracy, but external devices often lack consistent sensitivity and accuracy, and cannot be calibrated or adjusted later. The difficulty lies in the complex wiring layout required for multiple external sensors and the need for bus communication, which involves protocol integration and data interference. Third, traditional integrated fume purification control systems lack IoT modules, preventing remote control, remote data monitoring, and access to big data platforms for data storage, analysis, mining, and further data value analysis.

[0004] Therefore, how to enable the fume purifier to directly monitor and collect working environment parameters so that an external server can directly control the fume purifier is a technical problem that needs to be solved by those skilled in the art. Utility Model Content

[0005] The purpose of this invention is to solve the technical problem that existing oil fume purifiers cannot directly monitor and collect working environment parameters. Therefore, this invention provides an oil fume purifier control circuit, which includes: The sensor module is connected to each sensor via a data acquisition bus, and is also connected to the controller. A wireless module, connected to the controller, is used to transmit data to an external server or receive external commands. The display module, connected to the controller, is used to display the data collected by each sensor; The power supply module provides power to the controller, sensor module, wireless module, and display module.

[0006] Furthermore, the display module specifically includes: Port 1 of terminal J49 on the display panel is connected to a 12V power supply, port 2 of terminal J49 is grounded, and ports 3 and 4 of terminal J49 are both connected to the controller.

[0007] Furthermore, the wireless module includes a WiFi module and a 4G module, wherein the WiFi module specifically includes: Pin 1 of chip U24 is grounded. Pins 2, 5, 6, 7, 8, 9, 12, 13, 14 and 15 of chip U24 are all connected to the controller. Pin 16 of chip U24 is connected to a 3.3V power supply, one end of capacitor C65 and one end of capacitor C66, respectively. The other ends of capacitor C65 and capacitor C66 are both grounded.

[0008] Furthermore, the 4G module specifically includes: Pin 1 of chip U25 is connected to the controller via resistor R187; pin 2 of chip U25 is connected to the controller via resistor R186; pin 3 of chip U25 is connected to the controller via resistor R189; pin 4 of chip U25 is connected to the controller via resistor R188; pin 5 of chip U25 is connected to the controller via resistor R191; pin 6 of chip U25 is connected to the controller via resistor R190; pins 7 and 8 of chip U25 are both connected to the controller; pin 13 of chip U25 is grounded; pin 16 of chip U25 is connected to a 5V power supply, one end of capacitor C84, and one end of capacitor C85, respectively; the other ends of capacitor C84 and capacitor C85 are both grounded; pins 17 and 18 of chip U25 are both grounded.

[0009] Furthermore, the sensor module specifically includes: Port 1 of terminal J26 of the fume sensor is connected to one end of fuse F12. The other end of fuse F12 is connected to a 9.25V power supply and one end of capacitor C96, respectively. Port 2 of terminal J26 and the other end of capacitor C96 are both grounded. Ports 3 and 4 of terminal J26 are both connected to the controller. Port 1 of terminal J27 of the water flow sensor is connected to one end of fuse F13. The other end of fuse F13 is connected to a 9.5V power supply and one end of capacitor C95. The other end of capacitor C95 is grounded. Port 2 of terminal J27 is grounded. Port 3 of terminal J27 is connected to one end of resistor R77. The other end of resistor R77 is connected to the controller and one end of resistor R171. The other end of resistor R171 is grounded. Port 1 of terminal J28 of the gesture sensor is connected to one end of fuse F15. The other end of fuse F15 is connected to a 3.3V power supply and one end of capacitor C94. The other end of capacitor C94 and port 2 of terminal J28 are both grounded. Port 3 of terminal J28 is connected to the controller through resistor R90. Port 4 of terminal J28 is connected to the controller through resistor R91. Port 5 of terminal J28 is connected to the controller through resistor R83. Port 1 of terminal J29 of the wind pressure sensor is connected to a 12V power supply, port 2 of terminal J29 is grounded, and ports 3 and 4 of terminal J29 are both connected to the controller. Port 1 of terminal J30 of the ozone sensor is connected to a 12V power supply, port 2 of terminal J30 is grounded, and ports 3 and 4 of terminal J30 are both connected to the controller. Port 1 of terminal J32 of the noise sensor is connected to a 12V power supply, port 2 of terminal J32 is grounded, and ports 3 and 4 of terminal J32 are both connected to the controller.

[0010] Furthermore, the controller specifically includes: Pin 24 of chip U20 is connected to the power module; pins 25 and 26 of chip U20 are both connected to the sensor module; pins 29 to 31 of chip U20 are all connected to the undervoltage and overvoltage detection circuit; pin 67 of chip U20 is connected to LED3; pin 68 of chip U20 is connected to the wireless module through resistor R180; pin 69 of chip U20 is connected to the wireless module through resistor R179; pin 70 of chip U20 is connected to LED0; pin 71 of chip U20 is connected to LED1; and pin 72 of chip U20 is connected to... R182 and R89 are connected to a 3.3V power supply. Pin 76 of chip U20 is grounded via resistors R181 and R100. Pin 77 of chip U20 is connected to a gas leak detection sensor. Pin 37 of chip U20 is grounded via resistor R104. Pin 89 of chip U20 is connected to a water flow sensor. Pin 91 of chip U20 is connected to LED2. Pin 92 of chip U20 is connected to a 3.3V power supply via resistors R184 and R105. Pin 93 of chip U20 is connected via resistors R185 and R10... Pin 52 of chip U20 is connected to the 3.3V power supply via resistor R112, pin 53 of chip U20 is connected to the 3.3V power supply via resistor R113, one end of resistor R113 is also connected to one end of resistor R112, one end of resistor R107, and one end of resistor R105, pin 95 of chip U20 is connected to LED4, pin 96 of chip U20 is connected to LED5, pin 47 of chip U20 is connected to the UART2_TX terminal via resistor R114, and pin 48 of chip U20 is connected to the UART2_TX terminal via resistor R115. Connected to the UART3_RX terminal, pins 51 and 52 of chip U20 are both connected to the gesture recognition sensor. Pins 15 to 17 of chip U20 are all connected to the high-voltage power supply acquisition module, which is used to acquire the output voltage and current of the DC high-voltage power supply. Pin 18 of chip U20 is connected to one end of resistor R155. The other end of resistor R155 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to the other end of resistor R132, the reset button RESET, and one end of capacitor C76. One end of resistor R132 is connected to 3...A 3V power supply is connected. The other end of capacitor C76 and the emitter of transistor Q2 are both grounded. Pins 63 to 66 of chip U20 are connected to the wireless module. Pin 78 of chip U20 is connected to the display module through resistor R175. Pin 79 of chip U20 is connected to the display module through resistor R176. Pin 80 of chip U20 is connected to the wireless module through resistor R177. Pin 14 of chip U20 is connected to the reset button RESET through resistor R183. Pin 94 of chip U20 is grounded through resistor R134. Pin 90 of chip U20 is connected to port 1 of terminal J38 through resistor R144. Port 2 of terminal J38 is connected to... Resistor R145 is connected to pin 81 of chip U20. Port 3 of terminal J38 is connected to pin 82 of chip U20 via resistor R146. Pin 83 of chip U20 is connected to the wireless module via resistor R178. Pins 84 to 87 of chip U20 are all connected to the wireless module. Pin 88 of chip U20 is connected to the reset port of the wireless module. Pins 61 and 62 of chip U20 are both connected to the wireless module. Pins 97 and pins 1 to 5 of chip U20 are all connected to the wireless module. Pin 13 of chip U20 is connected to port 3 of crystal oscillator X1 and one end of resistor R117. The other end of resistor R117 is connected to pin 12 of chip U20 and the crystal oscillator X1. The crystal oscillator X1 is connected to port 1, which is also connected to the other end of capacitor C58. One end of capacitor C58 is grounded, and one end of capacitor C58 is also connected to port 4, port 2 of crystal oscillator X1, and one end of capacitor C57. The other end of capacitor C57 is connected to port 3 of crystal oscillator X1. Pin 21 of chip U20 is connected to one end of capacitor C104, one end of capacitor C106, and port 8 of chip U27. Pin 20 of chip U20 is connected to the other end of capacitor C104 and the other end of capacitor C106. Port 8 of chip U27 is also connected to the other end of resistor R173 and one end of resistor R174. One end of resistor R173 is also connected to... Port 1 of chip U27 is connected to the other end of resistor R172. One end of resistor R172 is connected to a 3.3V power supply. Port 1 of chip U27 is also connected to one end of capacitor C107 and one end of capacitor C105. The other ends of capacitors C107 and C105 are both grounded. Ports 2 and 3 of chip U27 are both connected to one end of ferrite bead FB1. One end of ferrite bead FB1 is also connected to ports 6 and 7 of chip U27 and the other end of resistor R174. The other end of ferrite bead FB1 is grounded. Pin 19 of chip U20 is grounded. Pins 22, 50, 75, 100, 28, and 11 of chip U20 are all connected to 3.3V power supply.With a 3V power supply connection, pins 49, 74, 99, 27, and 10 of chip U20 are all grounded.

[0011] Furthermore, the circuit also includes a phase error and phase loss detection circuit, and an undervoltage and overvoltage detection circuit, wherein: The phase error and phase loss detection circuit includes three sub-circuits with the same structure, namely the first sub-circuit, the second sub-circuit, and the third sub-circuit. The input terminals of the first sub-circuit, the second sub-circuit, and the third sub-circuit are connected to the three-phase power supply at the power input terminal of the fume purifier. Each sub-circuit is connected to only one phase power supply and outputs a level signal. The undervoltage and overvoltage detection circuit is used to convert three-phase electricity into voltage and current for voltage detection. It includes three voltage detection sub-circuits with the same structure: the first voltage detection sub-circuit, the second voltage detection sub-circuit, and the third voltage detection sub-circuit. The input terminals of the first voltage detection sub-circuit, the second voltage detection sub-circuit, and the third voltage detection sub-circuit are all connected to the terminal J41 at the power input terminal of the fume purifier.

[0012] Furthermore, the first sub-circuit specifically includes: The other end of resistor R17 is connected to the first phase L1. One end of R17 is connected to one end of resistor R16. The other end of resistor R16 is connected to the positive terminal of LED D1. The negative terminal of LED D1 is connected to the negative terminal of diode D4 and port 1 of optocoupler U4. Port 2 of optocoupler U4 is connected to the positive terminal of diode D4. Ports 1 and 2 of optocoupler U4 are connected internally through a diode. Port 3 of optocoupler U4 is grounded. Port 4 of optocoupler U4 is connected to one end of resistor R2 and one end of resistor R3. One end of resistor R2 is connected to a 3.3V power supply. The other end of resistor R3 is connected to the I / O detection port in the controller.

[0013] Furthermore, the first voltage detection sub-circuit specifically includes: Port 2 of relay U5 is connected to port 1 of terminal J41 and the input terminal of the first voltage signal acquisition circuit. Port 1 of relay U5 is connected to port 3 of current transformer CT1. Port 4 of current transformer CT1 is connected to port 1 of terminal J42. Terminal J42 is used to output three-phase 380V power to the working unit of the fume purifier. Port 3 of relay U5 is connected to a 12V power supply, the negative terminal of diode D3, and one end of resistor R21. The other end of resistor R21 is connected to the positive terminal of LED2. The positive terminal of diode D3 and the negative terminal of LED2 are both connected to port 4 of relay U5. Port 4 of relay U5 is also connected to the controller. Ports 2 and 1 of current transformer CT1 are both connected to the input terminal of the first differential signal sampling circuit. The output terminals of the first voltage signal acquisition circuit and the first differential signal sampling circuit are both connected to the voltage and current detection chip U1. The voltage and current sampling chip U1 is also connected to the controller.

[0014] Compared with the prior art, the beneficial effects of this utility model are: This utility model provides a control circuit for an oil fume purifier. Compared with the prior art, this circuit includes a sensor module connected to various sensors via a data acquisition bus, and the sensor module is also connected to a controller; a wireless module connected to the controller for transmitting data to an external server or receiving external commands; a display module connected to the controller for displaying the data collected by each sensor; and a power supply module that supplies power to the sensor module, wireless module, and display module, enabling the oil fume purifier to directly monitor and collect working environment parameters, so that the external server can directly control the oil fume purifier. Attached Figure Description

[0015] To more clearly illustrate the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 The diagram shown is a schematic diagram of the overall connection structure of the control circuit of the fume purifier provided in the embodiment of this specification. Figure 2 The diagram shown is a schematic diagram of the connection structure of the display module provided in the embodiment of this specification; Figure 3 The diagram shown is a schematic diagram of the connection structure of the WiFi module provided in the embodiment of this specification; Figure 4 The diagram shown is a schematic diagram of the connection structure of the 4G module provided in the embodiment of this specification; Figure 5 The diagram shown is a schematic diagram of the connection structure of the oil fume sensor provided in the embodiment of this specification; Figure 6 The diagram shown is a schematic diagram of the connection structure of the water flow sensor provided in the embodiment of this specification; Figure 7 The diagram shown is a schematic diagram of the connection structure of the gesture sensor provided in the embodiment of this specification; Figure 8 The diagram shown is a schematic diagram of the connection structure of the wind pressure sensor provided in the embodiment of this specification; Figure 9 The diagram shown is a schematic diagram of the connection structure of the ozone sensor provided in the embodiment of this specification; Figure 10 The diagram shown is a schematic diagram of the connection structure of the noise sensor provided in the embodiment of this specification; Figure 11 The diagram shown is a schematic diagram of the connection structure of the controller provided in the embodiment of this specification; Figure 12 The diagram shown is a schematic diagram of the connection structure of the phase error and phase loss detection circuit provided in the embodiment of this specification; Figure 13 The diagram shown is a schematic diagram of the connection structure of the undervoltage and overvoltage detection circuit provided in the embodiment of this specification. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0018] like Figure 1 The diagram shown is a schematic representation of the overall structure of the control circuit for an oil fume purifier provided in this embodiment. While this specification provides the structure shown in the following embodiments or figures, based on conventional methods or without creative effort, the structure may include more or fewer components combined. These structures are not limited to those shown in the embodiments or figures of this specification. In actual applications of devices or terminal products, the structures described can be executed sequentially or in parallel according to the embodiments or module structures.

[0019] The oil fume purifier control circuit provided in the embodiments of this specification includes: The sensor module is connected to each sensor via a data acquisition bus, and is also connected to the controller. A wireless module, connected to the controller, is used to transmit data to an external server or receive external commands. The display module, connected to the controller, is used to display the data collected by each sensor; The power supply module provides power to the controller, sensor module, wireless module, and display module.

[0020] Specifically, various sensing and detection devices are integrated into a single system and control board for data acquisition and control, significantly reducing the overall complexity of wiring and cabling for each sensor. This reduction in wiring enhances the overall anti-interference capability of the data acquisition process and simplifies subsequent maintenance. The integrated, centralized data acquisition and detection also facilitates comprehensive data analysis and application by external servers.

[0021] This application employs an embedded high-performance microcontroller as the brain of the intelligent control system to efficiently manage the integrated fume purification machine. Its nanosecond-level operating speed is sufficient to handle the data acquisition, uploading, and display of various sensors used on the integrated fume purification machine.

[0022] Furthermore, the integrated 4G or WIFI module on the control system of the fume purification unit can collect and report data, report anomalies, remotely control start and stop, remotely set parameters, or remotely upgrade programs. This is beneficial for supporting future IoT-enabled unmanned kitchens. A high-resolution smart central control screen (display module) equipped with an Android or Linux operating system can provide a 3D simulation of the entire control process, enhancing the interactivity and realism of the system. It can also display data collected by various sensors in real time and can be presented in multiple graphical formats, allowing users to more intuitively understand the overall operation of the system.

[0023] In the embodiments of this application, such as Figure 2 The diagram shows the connection structure of the display module, which specifically includes: Port 1 of terminal J49 on the display panel is connected to a 12V power supply, port 2 of terminal J49 is grounded, and ports 3 and 4 of terminal J49 are both connected to the controller.

[0024] The wireless module includes a WiFi module and a 4G module, such as Figure 3 The diagram shows the connection structure of a WiFi module, which specifically includes: Pin 1 of chip U24 is grounded. Pins 2, 5, 6, 7, 8, 9, 12, 13, 14 and 15 of chip U24 are all connected to the controller. Pin 16 of chip U24 is connected to a 3.3V power supply, one end of capacitor C65 and one end of capacitor C66, respectively. The other ends of capacitor C65 and capacitor C66 are both grounded.

[0025] like Figure 4 The diagram shows the connection structure of a 4G module, which specifically includes: Pin 1 of chip U25 is connected to the controller via resistor R187; pin 2 of chip U25 is connected to the controller via resistor R186; pin 3 of chip U25 is connected to the controller via resistor R189; pin 4 of chip U25 is connected to the controller via resistor R188; pin 5 of chip U25 is connected to the controller via resistor R191; pin 6 of chip U25 is connected to the controller via resistor R190; pins 7 and 8 of chip U25 are both connected to the controller; pin 13 of chip U25 is grounded; pin 16 of chip U25 is connected to a 5V power supply, one end of capacitor C84, and one end of capacitor C85, respectively; the other ends of capacitor C84 and capacitor C85 are both grounded; pins 17 and 18 of chip U25 are both grounded.

[0026] The sensor module specifically includes: like Figure 5 The diagram shows the connection structure of the fume sensor. Port 1 of terminal J26 of the fume sensor is connected to one end of fuse F12. The other end of fuse F12 is connected to a 9.25V power supply and one end of capacitor C96. Port 2 of terminal J26 and the other end of capacitor C96 are both grounded. Ports 3 and 4 of terminal J26 are both connected to the controller. like Figure 6 The diagram shows the connection structure of the water flow sensor. Port 1 of terminal J27 of the water flow sensor is connected to one end of fuse F13. The other end of fuse F13 is connected to a 9.5V power supply and one end of capacitor C95. The other end of capacitor C95 is grounded. Port 2 of terminal J27 is grounded. Port 3 of terminal J27 is connected to one end of resistor R77. The other end of resistor R77 is connected to the controller and one end of resistor R171. The other end of resistor R171 is grounded. like Figure 7The diagram shows the connection structure of the gesture sensor. Port 1 of terminal J28 of the gesture sensor is connected to one end of fuse F15. The other end of fuse F15 is connected to a 3.3V power supply and one end of capacitor C94. The other end of capacitor C94 and port 2 of terminal J28 are both grounded. Port 3 of terminal J28 is connected to the controller through resistor R90. Port 4 of terminal J28 is connected to the controller through resistor R91. Port 5 of terminal J28 is connected to the controller through resistor R83. like Figure 8 The diagram shows the connection structure of the wind pressure sensor. Port 1 of terminal J29 of the wind pressure sensor is connected to a 12V power supply, port 2 of terminal J29 is grounded, and ports 3 and 4 of terminal J29 are both connected to the controller. like Figure 9 The diagram shows the connection structure of the ozone sensor. Port 1 of terminal J30 of the ozone sensor is connected to a 12V power supply, port 2 of terminal J30 is grounded, and ports 3 and 4 of terminal J30 are both connected to the controller. like Figure 10 The diagram shows the connection structure of the noise sensor. Port 1 of terminal J32 of the noise sensor is connected to a 12V power supply, port 2 of terminal J32 is grounded, and ports 3 and 4 of terminal J32 are both connected to the controller.

[0027] The circuit also includes a phase error and phase loss detection circuit, and an undervoltage and overvoltage detection circuit, wherein: like Figure 12 The diagram shows the connection structure of the phase error and phase loss detection circuit. The phase error and phase loss detection circuit includes three sub-circuits with the same structure, namely the first sub-circuit, the second sub-circuit, and the third sub-circuit. The input terminals of the first sub-circuit, the second sub-circuit, and the third sub-circuit are connected to the three-phase power supply at the power input terminal of the fume purifier. Each sub-circuit is connected to only one phase power supply and outputs a level signal. like Figure 13 The diagram shows the connection structure of the undervoltage and overvoltage detection circuit. The undervoltage and overvoltage detection circuit is used to convert three-phase electricity into voltage and current for voltage detection. It includes three voltage detection sub-circuits with the same structure: the first voltage detection sub-circuit, the second voltage detection sub-circuit, and the third voltage detection sub-circuit. The input terminals of the first voltage detection sub-circuit, the second voltage detection sub-circuit, and the third voltage detection sub-circuit are all connected to the terminal J41 at the power input terminal of the fume purifier.

[0028] The first sub-circuit specifically includes: The other end of resistor R17 is connected to the first phase L1. One end of R17 is connected to one end of resistor R16. The other end of resistor R16 is connected to the positive terminal of LED D1. The negative terminal of LED D1 is connected to the negative terminal of diode D4 and port 1 of optocoupler U4. Port 2 of optocoupler U4 is connected to the positive terminal of diode D4. Ports 1 and 2 of optocoupler U4 are connected internally through a diode. Port 3 of optocoupler U4 is grounded. Port 4 of optocoupler U4 is connected to one end of resistor R2 and one end of resistor R3. One end of resistor R2 is connected to a 3.3V power supply. The other end of resistor R3 is connected to the I / O detection port in the controller.

[0029] The second sub-circuit specifically includes: The other end of resistor R23 is connected to the second phase L2. One end of R23 is connected to one end of resistor R19. The other end of resistor R19 is connected to the positive terminal of LED D2. The negative terminal of LED D2 is connected to the negative terminal of diode D5 and port 1 of optocoupler U7. Port 2 of optocoupler U7 is connected to the positive terminal of diode D5. Ports 1 and 2 of optocoupler U7 are connected internally through a diode. Port 3 of optocoupler U7 is grounded. Port 4 of optocoupler U7 is connected to one end of resistor R7 and one end of resistor R8. One end of resistor R7 is connected to a 3.3V power supply. The other end of resistor R8 is connected to the I / O detection port in the controller.

[0030] The third sub-circuit includes: The other end of resistor R30 is connected to the third phase L3. One end of R30 is connected to one end of resistor R25. The other end of resistor R25 is connected to the positive terminal of LED D3. The negative terminal of LED D3 is connected to the negative terminal of diode D6 and port 1 of optocoupler U8. Port 2 of optocoupler U8 is connected to the positive terminal of diode D6. Ports 1 and 2 of optocoupler U8 are connected internally through a diode. Port 3 of optocoupler U8 is grounded. Port 4 of optocoupler U8 is connected to one end of resistor R11 and one end of resistor R14. One end of resistor R11 is connected to a 3.3V power supply. The other end of resistor R14 is connected to the I / O detection port in the controller.

[0031] The detection circuit can detect phase reversal and phase loss in three-phase AC 380V 50Hz power supply, and includes indicator lights to visually display the power status of each phase. The high-voltage acquisition and low-voltage detection sections of this circuit use optocoupler isolation, ensuring a safe and reliable detection solution. This circuit requires an embedded program to detect and determine phase reversal and phase loss. In the diagram, L1, L2, and L3 are the three live wires connected to the AC 380V power supply. L1-CHECK, L2-CHECK, and L3-CHECK are connected to the three I / O detection ports of the microcontroller. The detection circuits for L1, L2, and L3 are identical. In phase L1, R16 and R17 are current-limiting resistors, limiting the current of LED D1 and the photodiode of optocoupler U4. D4 provides a freewheeling path for the positive and negative half-axis waveforms of the AC power supply. When the positive half-cycle of the sinusoidal AC signal passes through L1, reaching the conduction voltage of the LED, it will cause LED D1 and the photodiode of optocoupler U4 to conduct. At this time, LED D1 lights up, and the phototransistor at the output of U4 conducts, pulling the level signal low to GND. Therefore, the L1-CHECK port outputs a low level. When a low level is detected, it indicates that the voltage of this phase is normal and there is no phase loss. When the sinusoidal AC signal is in the negative half-cycle, phase L1 does not conduct, the LED D1 indicator light does not light up, and the L1-CHECK port outputs a high level. The MCU detects a high level and judges it as a phase loss. (Note that all LEDs here flash at a frequency greater than 50Hz, i.e., they light up and turn off intermittently. Because it is AC, they will only light up when the signal is in the positive half-cycle and the voltage is greater than the diode conduction voltage. They will not light up when the signal is in the negative half-cycle.)

[0032] This section analyzes the phase misalignment detection of three-phase AC signals. When the phase sequence is positive, the phase order is L1, L2, L3, and the phase difference between any two adjacent phases is 120 degrees. Specifically, the phase difference between L1 and L2 is 120 degrees, the phase difference between L2 and L3 is 120 degrees, and the phase difference between L3 and L1 is 120 degrees. When the AC signals are input into the circuit in the positive phase sequence according to the phase order L1, L2, L3, the output waveform of each optocoupler is a square wave signal of about 50Hz, with a period of about 20 milliseconds. Moreover, the time period difference between the three adjacent square wave signals L1-CHECK, L2-CHECK, and L3-CHECK remains at about 6 milliseconds (this is mainly related to the forward voltage drop of the LEDs). When the phase sequence is reversed, if the phase order is L1, L3, L2, the phase difference between any two adjacent phases is still 120 degrees. However, this becomes a 120-degree phase difference between L1 and L3, L3 and L2, and L2 and L1. When the phase sequence is reversed and AC signals are input into the circuit in the order L1, L3, L2, the output waveform of each optocoupler is still a square wave signal of approximately 50Hz, with a period of approximately 20 milliseconds. At this time, the time period difference of the square wave signals between the three adjacent L1-CHECK, L3-CHECK, and L2-CHECK channels is approximately 6 milliseconds, but the time period difference between the square wave signals between L1-CHECK and L2-CHECK becomes approximately 13 milliseconds. In summary, by detecting the time difference of the square wave signals between two phases, the phase sequence misalignment of the three-phase AC voltage can be identified.

[0033] In other words, the phase error and phase loss detection circuit collects the time difference of the square wave signal between two phases. Then the controller compares the time difference of the square wave signal with the standard time difference. If they match, the phase is correct; if they do not match, the phase is incorrect or a phase is missing. Moreover, this comparison is only a simple comparison function, which most controllers can implement. Alternatively, the controller can transmit the time difference of the square wave signal between two phases to the server via a WiFi module or a 4G module, and the server will make a judgment and receive instructions from the server via the WiFi module or the 4G module.

[0034] like Figure 13 The diagram shows the structure of an undervoltage and overvoltage detection circuit. This circuit converts three-phase electricity into voltage and current for voltage detection. It includes three identical voltage detection sub-circuits: a first voltage detection sub-circuit, a second voltage detection sub-circuit, and a third voltage detection sub-circuit. The input terminals of the first, second, and third voltage detection sub-circuits are all connected to terminal J41 at the power input of the fume purifier. The first voltage detection sub-circuit specifically includes: Port 2 of relay U5 is connected to port 1 of terminal J41 and the input terminal of the first voltage signal acquisition circuit. Port 1 of relay U5 is connected to port 3 of current transformer CT1. Port 4 of current transformer CT1 is connected to port 1 of terminal J42. Terminal J42 is used to output three-phase 380V power to the working unit of the fume purifier. Port 3 of relay U5 is connected to a 12V power supply, the negative terminal of diode D3, and one end of resistor R21. The other end of resistor R21 is connected to the positive terminal of LED2. The positive terminal of diode D3 and the negative terminal of LED2 are both connected to port 4 of relay U5. Port 4 of relay U5 is also connected to the controller. Ports 2 and 1 of current transformer CT1 are both connected to the input terminal of the first differential signal sampling circuit. The output terminals of the first voltage signal acquisition circuit and the first differential signal sampling circuit are both connected to the voltage and current detection chip U1. The voltage and current sampling chip U1 is also connected to the controller.

[0035] Specifically, the first voltage signal acquisition circuit includes: Port 1 of current transformer T1 is connected to the power supply module. Port 2 of current transformer T1 is connected to port 2 of relay U5 through resistors R19 and R12 in sequence. Port 4 of current transformer T1 is connected to voltage and current detection chip U1 through resistor R13. Port 4 of current transformer T1 is also connected to port 3 of current transformer T1 through resistor R17. Port 3 of current transformer T1 is also grounded.

[0036] The first differential signal sampling circuit includes: One end of resistor R1 and one end of resistor R4 are both connected to port 2 of current transformer CT1. The other end of resistor R4 and one end of resistor R7 are both connected to port 1 of current transformer CT1. The other end of resistor R1 is connected to the other end of capacitor C4 and voltage and current detection chip U1 respectively. The other end of resistor R7 is connected to the other end of capacitor C7 and voltage and current detection chip U1 respectively. One end of capacitor C4 and one end of capacitor C7 are both grounded.

[0037] The second voltage detection sub-circuit specifically includes: Port 2 of relay U10 is connected to port 2 of terminal J41 and the input terminal of the second voltage signal acquisition circuit. Port 1 of relay U10 is connected to port 3 of current transformer CT4. Port 4 of current transformer CT4 is connected to port 2 of terminal J42. Port 3 of relay U10 is connected to a 12V power supply, the negative terminal of diode D6, and one end of resistor R49. The other end of resistor R49 is connected to the positive terminal of LED4. The positive terminal of diode D6 and the negative terminal of LED4 are both connected to port 4 of relay U10. Port 4 of relay U5 is also connected to the controller. Ports 2 and 1 of current transformer CT4 are both connected to the input terminal of the second differential signal sampling circuit. The output terminals of the second voltage signal acquisition circuit and the second differential signal sampling circuit are both connected to the voltage and current detection chip U7.

[0038] The second voltage signal acquisition circuit specifically includes: Port 1 of current transformer T2 is connected to the power supply module. Port 2 of current transformer T2 is connected to port 2 of relay U10 through resistors R43 and R40 in sequence. Port 4 of current transformer T2 is connected to voltage and current detection chip U1 through resistor R38. Port 4 of current transformer T2 is also connected to port 3 of current transformer T2 through resistor R44. Port 3 of current transformer T2 is also grounded.

[0039] The second differential signal sampling circuit includes: One end of resistor R29 and one end of resistor R35 are both connected to port 2 of current transformer CT4. The other end of resistor R35 and one end of resistor R37 are both connected to port 1 of current transformer CT4. The other end of resistor R29 is connected to the other end of capacitor C16 and voltage and current detection chip U7 respectively. The other end of resistor R37 is connected to the other end of capacitor C19 and voltage and current detection chip U7 respectively. One end of capacitor C16 and one end of capacitor C19 are both grounded.

[0040] The third voltage detection sub-circuit specifically includes: Port 2 of relay U14 is connected to port 3 of terminal J41 and the input terminal of the third voltage signal acquisition circuit. Port 1 of relay U14 is connected to port 3 of current transformer CT7. Port 4 of current transformer CT7 is connected to port 3 of terminal J42. Port 3 of relay U14 is connected to a 12V power supply, the negative terminal of diode D11, and one end of resistor R66. The other end of resistor R66 is connected to the positive terminal of LED7. The positive terminal of diode D11 and the negative terminal of LED7 are both connected to port 4 of relay U14. Port 4 of relay U14 is also connected to the controller. Ports 2 and 1 of current transformer CT7 are both connected to the input terminal of the third differential signal sampling circuit. The output terminals of the third voltage signal acquisition circuit and the third differential signal sampling circuit are both connected to the voltage and current detection chip U11.

[0041] The third voltage signal acquisition circuit specifically includes: Port 1 of current transformer T3 is connected to the power supply module. Port 2 of current transformer T3 is connected to port 2 of relay U14 in sequence through resistor R64 and resistor R59. Port 4 of current transformer T3 is connected to voltage and current detection chip U11 through resistor R60. Port 4 of current transformer T3 is also connected to port 3 of current transformer T3 through resistor R65. Port 3 of current transformer T3 is also grounded.

[0042] The third differential signal sampling circuit includes: One end of resistor R52 and one end of resistor R54 are both connected to port 2 of current transformer CT7. The other end of resistor R54 and one end of resistor R57 are both connected to port 1 of current transformer CT7. The other end of resistor R52 is connected to the other end of capacitor C26 and voltage and current detection chip U11 respectively. The other end of resistor R57 is connected to the other end of capacitor C29 and voltage and current detection chip U11 respectively. One end of capacitor C26 and one end of capacitor C29 are both grounded.

[0043] A current transformer converts high-voltage current into low-voltage current, making it compatible with the sampling range of a voltage and current sampling chip. Furthermore, the current transformer isolates high-voltage and low-voltage currents, enabling isolated sampling. A differential signal sampling circuit allows current to pass through a sampling resistor, forming an AC voltage signal across it. This signal is then sampled via a differential circuit. The voltage signal acquisition circuit limits the current through two resistors, ensuring the input current of the voltage transformer remains within the specified range. The use of two resistors is necessary because ordinary resistors typically have a voltage rating of 220V, requiring voltage division. The output of the voltage transformer then forms a voltage signal within the sampling range through a resistor, while another resistor prevents excessive input current and achieves isolation between high-voltage and low-voltage currents.

[0044] like Figure 11 The diagram shows the connection structure of the controller: Pin 24 of chip U20 is connected to the power module; pins 25 and 26 of chip U20 are both connected to the sensor module; pins 29 to 31 of chip U20 are all connected to the undervoltage and overvoltage detection circuit; pin 67 of chip U20 is connected to LED3; pin 68 of chip U20 is connected to the wireless module through resistor R180; pin 69 of chip U20 is connected to the wireless module through resistor R179; pin 70 of chip U20 is connected to LED0; pin 71 of chip U20 is connected to LED1; and pin 72 of chip U20 is connected to... R182 and R89 are connected to a 3.3V power supply. Pin 76 of chip U20 is grounded via resistors R181 and R100. Pin 77 of chip U20 is connected to a gas leak detection sensor. Pin 37 of chip U20 is grounded via resistor R104. Pin 89 of chip U20 is connected to a water flow sensor. Pin 91 of chip U20 is connected to LED2. Pin 92 of chip U20 is connected to a 3.3V power supply via resistors R184 and R105. Pin 93 of chip U20 is connected via resistors R185 and R10... Pin 52 of chip U20 is connected to the 3.3V power supply via resistor R112, pin 53 of chip U20 is connected to the 3.3V power supply via resistor R113, one end of resistor R113 is also connected to one end of resistor R112, one end of resistor R107, and one end of resistor R105, pin 95 of chip U20 is connected to LED4, pin 96 of chip U20 is connected to LED5, pin 47 of chip U20 is connected to the UART2_TX terminal via resistor R114, and pin 48 of chip U20 is connected to the UART2_TX terminal via resistor R115. Connected to the UART3_RX terminal, pins 51 and 52 of chip U20 are both connected to the gesture recognition sensor. Pins 15 to 17 of chip U20 are all connected to the high-voltage power supply acquisition module, which is used to acquire the output voltage and current of the DC high-voltage power supply. Pin 18 of chip U20 is connected to one end of resistor R155. The other end of resistor R155 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to the other end of resistor R132, the reset button RESET, and one end of capacitor C76. One end of resistor R132 is connected to 3...A 3V power supply is connected. The other end of capacitor C76 and the emitter of transistor Q2 are both grounded. Pins 63 to 66 of chip U20 are connected to the wireless module. Pin 78 of chip U20 is connected to the display module through resistor R175. Pin 79 of chip U20 is connected to the display module through resistor R176. Pin 80 of chip U20 is connected to the wireless module through resistor R177. Pin 14 of chip U20 is connected to the reset button RESET through resistor R183. Pin 94 of chip U20 is grounded through resistor R134. Pin 90 of chip U20 is connected to port 1 of terminal J38 through resistor R144. Port 2 of terminal J38 is connected to... Resistor R145 is connected to pin 81 of chip U20. Port 3 of terminal J38 is connected to pin 82 of chip U20 via resistor R146. Pin 83 of chip U20 is connected to the wireless module via resistor R178. Pins 84 to 87 of chip U20 are all connected to the wireless module. Pin 88 of chip U20 is connected to the reset port of the wireless module. Pins 61 and 62 of chip U20 are both connected to the wireless module. Pins 97 and pins 1 to 5 of chip U20 are all connected to the wireless module. Pin 13 of chip U20 is connected to port 3 of crystal oscillator X1 and one end of resistor R117. The other end of resistor R117 is connected to pin 12 of chip U20 and the crystal oscillator X1. The crystal oscillator X1 is connected to port 1, which is also connected to the other end of capacitor C58. One end of capacitor C58 is grounded, and one end of capacitor C58 is also connected to port 4, port 2 of crystal oscillator X1, and one end of capacitor C57. The other end of capacitor C57 is connected to port 3 of crystal oscillator X1. Pin 21 of chip U20 is connected to one end of capacitor C104, one end of capacitor C106, and port 8 of chip U27. Pin 20 of chip U20 is connected to the other end of capacitor C104 and the other end of capacitor C106. Port 8 of chip U27 is also connected to the other end of resistor R173 and one end of resistor R174. One end of resistor R173 is also connected to... Port 1 of chip U27 is connected to the other end of resistor R172. One end of resistor R172 is connected to a 3.3V power supply. Port 1 of chip U27 is also connected to one end of capacitor C107 and one end of capacitor C105. The other ends of capacitors C107 and C105 are both grounded. Ports 2 and 3 of chip U27 are both connected to one end of ferrite bead FB1. One end of ferrite bead FB1 is also connected to ports 6 and 7 of chip U27 and the other end of resistor R174. The other end of ferrite bead FB1 is grounded. Pin 19 of chip U20 is grounded. Pins 22, 50, 75, 100, 28, and 11 of chip U20 are all connected to 3.3V power supply.With a 3V power supply connection, pins 49, 74, 99, 27, and 10 of chip U20 are all grounded.

[0045] It should be understood that when an element is referred to as “fixed to” or “set on” another element, it may be directly on the other element or may be interposed with an intervening element; when an element is referred to as “connected to” another element, it may be directly connected to the other element or may be interposed with an intervening element. Furthermore, the term “connected” as used herein may include wireless connections; the word “and / or” as used includes any and all combinations of one or more of the associated listed items.

[0046] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0047] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0048] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0049] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0050] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

[0052] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A control circuit for an oil fume purifier, characterized in that, The circuit includes: The sensor module is connected to each sensor via a data acquisition bus, and is also connected to the controller. A wireless module, connected to the controller, is used to transmit data to an external server or receive external commands. The display module, connected to the controller, is used to display the data collected by each sensor; The power supply module provides power to the controller, sensor module, wireless module, and display module respectively. Specifically, the sensor module includes: Port 1 of terminal J26 of the fume sensor is connected to one end of fuse F12. The other end of fuse F12 is connected to a 9.25V power supply and one end of capacitor C96, respectively. Port 2 of terminal J26 and the other end of capacitor C96 are both grounded. Ports 3 and 4 of terminal J26 are both connected to the controller. Port 1 of terminal J27 of the water flow sensor is connected to one end of fuse F13. The other end of fuse F13 is connected to a 9.5V power supply and one end of capacitor C95. The other end of capacitor C95 is grounded. Port 2 of terminal J27 is grounded. Port 3 of terminal J27 is connected to one end of resistor R77. The other end of resistor R77 is connected to the controller and one end of resistor R171. The other end of resistor R171 is grounded. Port 1 of terminal J28 of the gesture sensor is connected to one end of fuse F15. The other end of fuse F15 is connected to a 3.3V power supply and one end of capacitor C94. The other end of capacitor C94 and port 2 of terminal J28 are both grounded. Port 3 of terminal J28 is connected to the controller through resistor R90. Port 4 of terminal J28 is connected to the controller through resistor R91. Port 5 of terminal J28 is connected to the controller through resistor R83. Port 1 of terminal J29 of the wind pressure sensor is connected to a 12V power supply, port 2 of terminal J29 is grounded, and ports 3 and 4 of terminal J29 are both connected to the controller. Port 1 of terminal J30 of the ozone sensor is connected to a 12V power supply, port 2 of terminal J30 is grounded, and ports 3 and 4 of terminal J30 are both connected to the controller. Port 1 of terminal J32 of the noise sensor is connected to a 12V power supply, port 2 of terminal J32 is grounded, and ports 3 and 4 of terminal J32 are both connected to the controller.

2. The control circuit for the fume purifier as described in claim 1, characterized in that, The display module specifically includes: Port 1 of terminal J49 on the display panel is connected to a 12V power supply, port 2 of terminal J49 is grounded, and ports 3 and 4 of terminal J49 are both connected to the controller.

3. The control circuit for the fume purifier as described in claim 1, characterized in that, The wireless module includes a WiFi module and a 4G module, and the WiFi module specifically includes: Pin 1 of chip U24 is grounded. Pins 2, 5, 6, 7, 8, 9, 12, 13, 14 and 15 of chip U24 are all connected to the controller. Pin 16 of chip U24 is connected to a 3.3V power supply, one end of capacitor C65 and one end of capacitor C66, respectively. The other ends of capacitor C65 and capacitor C66 are both grounded.

4. The control circuit for the fume purifier as described in claim 3, characterized in that, The 4G module specifically includes: Pin 1 of chip U25 is connected to the controller via resistor R187; pin 2 of chip U25 is connected to the controller via resistor R186; pin 3 of chip U25 is connected to the controller via resistor R189; pin 4 of chip U25 is connected to the controller via resistor R188; pin 5 of chip U25 is connected to the controller via resistor R191; pin 6 of chip U25 is connected to the controller via resistor R190; pins 7 and 8 of chip U25 are both connected to the controller; pin 13 of chip U25 is grounded; pin 16 of chip U25 is connected to a 5V power supply, one end of capacitor C84, and one end of capacitor C85, respectively; the other ends of capacitor C84 and capacitor C85 are both grounded; pins 17 and 18 of chip U25 are both grounded.

5. The control circuit for the fume purifier as described in claim 1, characterized in that, The controller specifically includes: Pin 24 of chip U20 is connected to the power module; pins 25 and 26 of chip U20 are both connected to the sensor module; pins 29 to 31 of chip U20 are all connected to the undervoltage and overvoltage detection circuit; pin 67 of chip U20 is connected to LED3; pin 68 of chip U20 is connected to the wireless module through resistor R180; pin 69 of chip U20 is connected to the wireless module through resistor R179; pin 70 of chip U20 is connected to LED0; pin 71 of chip U20 is connected to LED1; and pin 72 of chip U20 is connected to... R182 and R89 are connected to a 3.3V power supply. Pin 76 of chip U20 is grounded via resistors R181 and R100. Pin 77 of chip U20 is connected to a gas leak detection sensor. Pin 37 of chip U20 is grounded via resistor R104. Pin 89 of chip U20 is connected to a water flow sensor. Pin 91 of chip U20 is connected to LED2. Pin 92 of chip U20 is connected to a 3.3V power supply via resistors R184 and R105. Pin 93 of chip U20 is connected via resistors R185 and R10... Pin 52 of chip U20 is connected to the 3.3V power supply via resistor R112, pin 53 of chip U20 is connected to the 3.3V power supply via resistor R113, one end of resistor R113 is also connected to one end of resistor R112, one end of resistor R107, and one end of resistor R105, pin 95 of chip U20 is connected to LED4, pin 96 of chip U20 is connected to LED5, pin 47 of chip U20 is connected to the UART2_TX terminal via resistor R114, and pin 48 of chip U20 is connected to the UART2_TX terminal via resistor R115. Connected to the UART3_RX terminal, pins 51 and 52 of chip U20 are both connected to the gesture recognition sensor. Pins 15 to 17 of chip U20 are all connected to the high-voltage power supply acquisition module, which is used to acquire the output voltage and current of the DC high-voltage power supply. Pin 18 of chip U20 is connected to one end of resistor R155. The other end of resistor R155 is connected to the base of transistor Q2. The collector of transistor Q2 is connected to the other end of resistor R132, the reset button RESET, and one end of capacitor C76. One end of resistor R132 is connected to 3...A 3V power supply is connected. The other end of capacitor C76 and the emitter of transistor Q2 are both grounded. Pins 63 to 66 of chip U20 are connected to the wireless module. Pin 78 of chip U20 is connected to the display module through resistor R175. Pin 79 of chip U20 is connected to the display module through resistor R176. Pin 80 of chip U20 is connected to the wireless module through resistor R177. Pin 14 of chip U20 is connected to the reset button RESET through resistor R183. Pin 94 of chip U20 is grounded through resistor R134. Pin 90 of chip U20 is connected to port 1 of terminal J38 through resistor R144. Port 2 of terminal J38 is connected to... Resistor R145 is connected to pin 81 of chip U20. Port 3 of terminal J38 is connected to pin 82 of chip U20 via resistor R146. Pin 83 of chip U20 is connected to the wireless module via resistor R178. Pins 84 to 87 of chip U20 are all connected to the wireless module. Pin 88 of chip U20 is connected to the reset port of the wireless module. Pins 61 and 62 of chip U20 are both connected to the wireless module. Pins 97 and pins 1 to 5 of chip U20 are all connected to the wireless module. Pin 13 of chip U20 is connected to port 3 of crystal oscillator X1 and one end of resistor R117. The other end of resistor R117 is connected to pin 12 of chip U20 and the crystal oscillator X1. The crystal oscillator X1 is connected to port 1, which is also connected to the other end of capacitor C58. One end of capacitor C58 is grounded, and one end of capacitor C58 is also connected to port 4, port 2 of crystal oscillator X1, and one end of capacitor C57. The other end of capacitor C57 is connected to port 3 of crystal oscillator X1. Pin 21 of chip U20 is connected to one end of capacitor C104, one end of capacitor C106, and port 8 of chip U27. Pin 20 of chip U20 is connected to the other end of capacitor C104 and the other end of capacitor C106. Port 8 of chip U27 is also connected to the other end of resistor R173 and one end of resistor R174. One end of resistor R173 is also connected to... Port 1 of chip U27 is connected to the other end of resistor R172. One end of resistor R172 is connected to a 3.3V power supply. Port 1 of chip U27 is also connected to one end of capacitor C107 and one end of capacitor C105. The other ends of capacitors C107 and C105 are both grounded. Ports 2 and 3 of chip U27 are both connected to one end of ferrite bead FB1. One end of ferrite bead FB1 is also connected to ports 6 and 7 of chip U27 and the other end of resistor R174. The other end of ferrite bead FB1 is grounded. Pin 19 of chip U20 is grounded. Pins 22, 50, 75, 100, 28, and 11 of chip U20 are all connected to 3.3V power supply.With a 3V power supply connection, pins 49, 74, 99, 27, and 10 of chip U20 are all grounded.

6. The control circuit for the fume purifier as described in claim 1, characterized in that, The circuit also includes a phase error and phase loss detection circuit, and an undervoltage and overvoltage detection circuit, wherein: The phase error and phase loss detection circuit includes three sub-circuits with the same structure, namely the first sub-circuit, the second sub-circuit, and the third sub-circuit. The input terminals of the first sub-circuit, the second sub-circuit, and the third sub-circuit are connected to the three-phase power supply at the power input terminal of the fume purifier. Each sub-circuit is connected to only one phase power supply and outputs a level signal. The undervoltage and overvoltage detection circuit is used to convert three-phase electricity into voltage and current for voltage detection. It includes three voltage detection sub-circuits with the same structure: the first voltage detection sub-circuit, the second voltage detection sub-circuit, and the third voltage detection sub-circuit. The input terminals of the first voltage detection sub-circuit, the second voltage detection sub-circuit, and the third voltage detection sub-circuit are all connected to the terminal J41 at the power input terminal of the fume purifier.

7. The control circuit for the fume purifier as described in claim 6, characterized in that, The first sub-circuit specifically includes: The other end of resistor R17 is connected to the first phase L1. One end of R17 is connected to one end of resistor R16. The other end of resistor R16 is connected to the positive terminal of LED D1. The negative terminal of LED D1 is connected to the negative terminal of diode D4 and port 1 of optocoupler U4. Port 2 of optocoupler U4 is connected to the positive terminal of diode D4. Ports 1 and 2 of optocoupler U4 are connected internally through a diode. Port 3 of optocoupler U4 is grounded. Port 4 of optocoupler U4 is connected to one end of resistor R2 and one end of resistor R3. One end of resistor R2 is connected to a 3.3V power supply. The other end of resistor R3 is connected to the I / O detection port in the controller.

8. The control circuit for the fume purifier as described in claim 6, characterized in that, The first voltage detection sub-circuit specifically includes: Port 2 of relay U5 is connected to port 1 of terminal J41 and the input terminal of the first voltage signal acquisition circuit. Port 1 of relay U5 is connected to port 3 of current transformer CT1. Port 4 of current transformer CT1 is connected to port 1 of terminal J42. Terminal J42 is used to output three-phase 380V power to the working unit of the fume purifier. Port 3 of relay U5 is connected to a 12V power supply, the negative terminal of diode D3, and one end of resistor R21. The other end of resistor R21 is connected to the positive terminal of LED2. The positive terminal of diode D3 and the negative terminal of LED2 are both connected to port 4 of relay U5. Port 4 of relay U5 is also connected to the controller. Ports 2 and 1 of current transformer CT1 are both connected to the input terminal of the first differential signal sampling circuit. The output terminals of the first voltage signal acquisition circuit and the first differential signal sampling circuit are both connected to the voltage and current detection chip U1. The voltage and current sampling chip U1 is also connected to the controller.

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