High-integration-level, high-precision and high-safety electronic limiting curtain drawing motor

Abstract

The utility model discloses a high-integration, high-precision and high-safety electronic limiting curtain drawing motor, and relates to the technical field of curtain drawing motors. The motor comprises a motor body, and further comprises a motor controller which is used for controlling the motor body to move; the motor controller comprises a single-chip microcomputer control unit, an open-phase judgment circuit, a phase sequence protection circuit, a reversing circuit, an intelligent voice broadcast circuit, a remote controller circuit, a key circuit, a position control magnetic encoder module, a mechanical limiting module and a power supply system circuit. The motor is controlled by a magnetic encoder and a chip, rotation information of a main shaft of the curtain drawing motor is converted into an electric signal, and high-precision positioning and free stroke are achieved. Phase sequence judgment is realized, and a phase sequence protection function unit is additionally arranged, so that a worker can perform wiring at will without judging the phase sequence, and the problem of complicated installation is solved; the self-developed stable power supply system avoids the risk of a switching power supply, solves the problem of power-off coordinate offset, and greatly reduces the failure rate.

Description

Technical Field

[0001] This utility model relates to the field of motor control device technology, and in particular to a highly integrated, high-precision, and highly safe electronic limit curtain motor. Background Technology

[0002] A greenhouse curtain motor is a type of motor reducer used in greenhouse shading and insulation systems. It primarily controls the raising and lowering of shading and insulation curtains. By controlling the opening and closing of these curtains, it regulates the light intensity and temperature inside the greenhouse, thus providing a suitable growing environment for crops. With the rapid development of modern agriculture in recent years, greenhouse curtain motors are increasingly being used in vegetable cultivation, fruit cultivation, seedling raising, breeding, flower cultivation, and even various livestock farms. In short, wherever greenhouses or livestock farms require internal insulation and shading, greenhouse curtain motors are needed.

[0003] Greenhouse curtain retractor motors typically employ a rack and pinion system. A geared motor drives a drive shaft, which in turn rotates the gears, causing the rack to reciprocate. Since the rack is integrated with a push-pull rod, the rod moves accordingly, ultimately expanding or retracting the shading curtain or insulation curtain. This design ensures accurate positioning and smooth operation of the motor when controlling the shading and insulation curtains.

[0004] Traditional greenhouse curtain motors have several drawbacks. Traditional curtain motors use a DWXC type mechanical limit switch, with a set of transmission gears running from the reducer's output shaft. The last gear is fixed to a lead screw, and the travel is determined by the movement of a set screw on the lead screw. When the set screw actuates a spring plate, opening a microswitch, the motor automatically stops. This limiting method has the following problems:

[0005] 1) The limit travel is limited by the number of turns of the lead screw thread, with a maximum travel of 75 turns, meaning the reducer output shaft can rotate a maximum of 75 times. After 75 turns, the nut has no more room to move on the lead screw and will be forcibly stopped. This makes it unsuitable for long-distance, large-stroke applications, limiting the development and innovation of more application scenarios.

[0006] 2) During motor installation and commissioning, a dedicated distribution box or controller must be used, with limit signal lines connected via contactors or relays. During installation, three-phase power is required to the motor, and three signal lines are needed to the limit switches. The phase sequence of the three-phase power and the phase sequence of the limit switch signal lines must be fixed. This increases the difficulty of installation and commissioning, as well as the operating cost. In practical applications, the following phenomena often occur: ①. Installers cannot distinguish the relationship between the motor's rotation direction and the direction of the limit signal lines, reversing the limit switch signal lines. This causes the microswitch to also reverse, preventing the limit switches from working properly. Overtravel can lead to the limit switches jamming the motor, causing overload and even motor burnout. In more serious cases, the motor may stop moving even after reaching its destination, damaging the shade net or insulation blanket; ②. Curtain motors are typically installed at a height of four to six meters above the ground. Depending on the travel length, the time required to adjust the limit switch travel varies from ten to forty minutes. This forces installers to work at height frequently and for extended periods, sometimes even working with live electricity. Taking a standard 6,000-square-meter glass curtain wall greenhouse as an example, this greenhouse typically installs four to eight curtain-pulling motors. Each motor requires installers to climb high, connect wires, and adjust limit switches. Installers working at heights need to use extremely small wrenches or screwdrivers for extended periods, which is dangerous, inefficient, and prone to errors. Furthermore, due to the complexity of the limit system, if the curtain-pulling motor or distribution box controller malfunctions, the owner lacks the ability to troubleshoot and resolve the problem independently, and must hire professional workers or maintenance companies. This not only incurs financial costs but also significant time losses. For greenhouse owners, the economic losses from a motor being unusable for one or two days are incalculable.

[0007] 3) Limit switch accuracy issues. The accuracy of limit switches in traditional curtain motors is affected by the meshing clearance of transmission gears, the thread clearance between the lead screw and nut, the deformation and return of the spring lever, the contact points of the microswitch, and its sensitivity. Their accuracy is often controlled at around 20cm at the factory, but it decreases over time. This leads to two problems: First, if driving an insulation system, this gap will affect the insulation effect, causing unnecessary energy waste in the greenhouse heating system; if driving a shading system, this gap will also affect the shading and heat dissipation effects, forcing crops that cannot be directly exposed to sunlight to relinquish a certain area in the greenhouse, resulting in wasted space and energy waste in the heat dissipation system; if driving a seedbed, this gap will also affect the lighting effect, and if redundancy is designed, it will result in wasted usable space. Secondly, there are other external issues that affect the limit travel, such as thermal expansion and contraction, fatigue of the curtain support line and ropes. Considering the complexity of adjusting the limit travel mentioned above, owners generally do not have the ability to adjust the limit position in a timely manner and also need to rely on professional workers or maintenance companies.

[0008] 4) Impact on Greenhouse Construction Companies. The completion of a modern greenhouse typically involves five stages: project initiation, construction, acceptance and delivery, commissioning, and final payment settlement. For greenhouse construction companies, during the acceptance stage, the greenhouse curtain motor is guaranteed to be properly installed and adjusted. However, after delivery to the owner, before the greenhouse officially goes into operation, the owner often readjusts the limit positions of the curtain motor based on actual operating conditions. Due to the complexity of traditional curtain motor adjustments, greenhouse construction companies cannot provide a "turnkey" service by simply providing the owner with the adjustment instructions. This results in the construction company needing to make one or even multiple on-site visits before commissioning, thus increasing installation costs and wasting time and manpower.

[0009] 5) Traditional motors use power switches, which are relatively large and often require external control boxes. Mechanical power switches control the circuit by closing and opening mechanical contacts. During frequent use, the contacts are prone to wear and tear, and prolonged exposure to air, coupled with the large current generated during motor commutation, can easily cause arcing. All of these factors can lead to oxidation of the contact surfaces, resulting in poor contact, affecting the normal function of the switch, shortening its lifespan, and even causing safety issues. Utility Model Content

[0010] The technical problem to be solved by this utility model is how to provide an electronically limited curtain motor based on magnetic control coding technology that has high positioning accuracy, is easy to install, and can greatly reduce the failure rate.

[0011] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a highly integrated, high-precision, and high-safety electronic limit curtain motor, including a motor body and a motor controller, which controls the movement of the motor body; the motor controller includes a single-chip microcomputer control unit, a phase loss judgment circuit bidirectionally connected to the single-chip microcomputer control unit, used to determine whether the motor body is missing a phase; a phase sequence protection circuit bidirectionally connected to the single-chip microcomputer control unit, used to determine whether the phase sequence of the motor body is incorrect; a commutation circuit bidirectionally connected to the single-chip microcomputer control unit, used to realize the commutation switching operation of the motor body; and an intelligent voice broadcasting circuit connected to the signal output terminal of the single-chip microcomputer control unit. The system includes a connection for transmitting voice signals under the control of the microcontroller control unit; a remote control circuit connected to the signal input terminal of the microcontroller control unit for receiving wireless remote control signals and controlling the motor controller to execute corresponding commands; a button circuit connected to the signal input terminal of the microcontroller control unit for manually inputting control commands; a position control magnetic encoder module bidirectionally connected to the microcontroller control unit for collecting the number of motor revolutions through inductive magnets; a mechanical limit module bidirectionally connected to the microcontroller control unit for limiting the position of the motor body; and a power supply system circuit connected to the power input terminal of the modules in the motor controller that require power, for providing them with operating power.

[0012] The beneficial effects of adopting the above technical solution are as follows: The curtain motor described in this application has both phase loss protection and phase sequence protection, which can not only avoid unstable motor operation or even motor or other core component failures or burnouts caused by phase loss, but also prevent equipment failures, mechanical collisions and other safety accidents caused by motor reversal due to incorrect phase sequence. When connected to power, the power cord can be directly connected, and the phase sequence can be connected arbitrarily. The system automatically judges and executes according to the set direction.

[0013] No dedicated distribution box or controller is required; all modules are integrated into the mechanical limit control position of the traditional motor, greatly saving space. A custom-made wire-wound transformer is used for voltage transformation, making the power supply more stable, improving safety, and extending service life. The supercapacitor gives the system a power failure memory function, eliminating inertial displacement deviation caused by sudden power loss of the motor, making positioning more accurate.

[0014] Employing a magnetic encoder, it features a relatively simple structure, small size, and light weight, facilitating installation and maintenance. Theoretically, it has no travel limit requirements. Utilizing the principle of detecting changes in the magnetic field and converting them into electrical signals, it can provide accurate position information in a short time, meeting the needs of innovative applications such as multi-size, fast feedback, and real-time control. It can achieve the measurement of minute displacements and precise angle detection, reaching a resolution of 1 micrometer. It also has good vibration resistance, meeting the high-precision requirements of various occasions. The non-contact measurement method eliminates performance degradation and malfunctions caused by friction and wear, enabling stable operation for extended periods. It has good anti-pollution capabilities and a wide temperature adaptability range, allowing it to operate stably in harsh environments such as dusty, oily, humid, high-temperature, or low-temperature conditions.

[0015] Equipped with voice broadcast function, it automatically broadcasts a series of alarms such as phase loss and incorrect wiring, as well as a series of operation prompts such as entering the setting mode and setting the starting point, which simplifies the adjustment steps, greatly improves the user experience, and reduces the later maintenance costs.

[0016] Using four relays with a self-locking mechanism to control commutation reduces space and costs; and the use of delay control during commutation switching effectively avoids arcing, extends service life, and improves operational stability and safety. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a schematic block diagram of the motor controller in the curtain-pulling motor described in this embodiment of the utility model;

[0019] Figure 2 This is a circuit diagram of the phase loss detection circuit in the controller described in this embodiment of the utility model;

[0020] Figure 3 This is a circuit diagram of the phase sequence protection circuit in the controller described in this embodiment of the utility model;

[0021] Figure 4 This is a circuit diagram of the commutation circuit in the controller described in this embodiment of the utility model;

[0022] Figure 5 This is a circuit diagram of the power supply system circuit in the controller described in this embodiment of the utility model;

[0023] Figure 6 This is a circuit diagram of the intelligent voice broadcasting circuit in the controller described in this embodiment of the utility model;

[0024] Figure 7 This is a circuit diagram of the button circuit in the controller described in this embodiment of the utility model;

[0025] Figure 8 This is a circuit diagram of the remote control circuit in the controller described in this embodiment of the utility model;

[0026] Figure 9 This is a circuit diagram of the position control magnetic encoder module in the controller described in this embodiment of the utility model;

[0027] Figure 10 This is a circuit diagram of the mechanical limit module in the controller described in this embodiment of the utility model;

[0028] Figure 11 This is a circuit diagram of the microcontroller control unit in the controller described in this embodiment of the utility model. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0031] like Figure 1As shown in the figure, this utility model discloses a highly integrated, high-precision, and high-safety electronic limit curtain motor, including a motor body and a motor controller. The motor controller is used to control the movement of the motor body. The motor controller includes a single-chip microcomputer control unit, a phase loss judgment circuit bidirectionally connected to the single-chip microcomputer control unit, used to determine whether the motor body is missing a phase; a phase sequence protection circuit bidirectionally connected to the single-chip microcomputer control unit, used to determine whether the phase sequence of the motor body is incorrect; a commutation circuit bidirectionally connected to the single-chip microcomputer control unit, used to realize the commutation switching operation of the motor body; and an intelligent voice broadcasting circuit connected to the signal output terminal of the single-chip microcomputer control unit, used to... The system emits voice signals under the control of the microcontroller control unit; the remote control circuit is connected to the signal input terminal of the microcontroller control unit to receive wireless remote control signals and control the motor controller to execute corresponding commands; the button circuit is connected to the signal input terminal of the microcontroller control unit for manual input of control commands; the position control magnetic encoder module is bidirectionally connected to the microcontroller control unit to collect the number of motor revolutions through inductive magnets; the mechanical limit module is bidirectionally connected to the microcontroller control unit to limit the position of the motor body; the power supply system circuit is connected to the power input terminal of the modules in the motor controller that require power to provide them with operating power. The motor controller also includes a communication module, which allows the motor controller to be connected to the Internet to control the entire curtain-pulling motor through a smart mobile terminal.

[0032] Furthermore, such as Figure 2 As shown, the phase loss detection circuit includes resistors R27-R32. One end of resistor R27 is connected to the three-phase power input port U, and the other end of resistor R27 is connected to pin 3 of switching diode DL1 via resistor R28. Pin 2 of DL1 is connected to one end of capacitor C20, and pin 1 of DL1 is connected to the other end of capacitor C20. One end of resistor R29 is connected to the three-phase power input port V, and the other end of resistor R29 is connected to pin 3 of switching diode DL2 via resistor R30. Pin 2 of DL2 is connected to one end of capacitor C20, and pin 1 of DL2 is connected to the other end of capacitor C20. One end of resistor R31 is connected to the three-phase power input port W, and the other end of resistor R31 is connected to pin 3 of switching diode DL3 via resistor R32. Pin 2 of DL3 is connected to one end of capacitor C20, and pin 1 of DL3 is connected to the other end of capacitor C20.

[0033] One end of capacitor C20 is connected to the positive terminal of the LED of optocoupler U6 via resistor R34, and the other end of capacitor C20 is connected to the negative terminal of the LED of optocoupler U6. One end of resistor R33 is connected to the negative terminal of the LED of optocoupler U6, and the other end of resistor R33 is connected to the junction of resistor R34 and capacitor C20. One end of resistor R35 is connected to the negative terminal of the LED of optocoupler U6, and the other end of resistor R35 is connected to the positive terminal of the LED of optocoupler U6.

[0034] The collector of the phototransistor in the optocoupler U6 is divided into four paths. The first path is connected to a 5V power supply via resistor R36. The second path is connected to a 5V power supply via LED10 and resistor R20. The third path is grounded via capacitor C21. The fourth path is connected to the corresponding pin of the microcontroller control unit. The emitter of the phototransistor in the optocoupler U6 is grounded.

[0035] like Figure 2 As shown, in the phase loss detection circuit, the U, V, and W phases are respectively charged by the three-phase rectifier module composed of BAT54 switching diodes DL1, DL2, and DL3 to charge capacitor C20. Then, the voltage is stepped down by resistors R33, R34, and R35 to provide power to the optocoupler U6. After passing through the filter circuit composed of parallel capacitor C21, LED10 reflects the power waveform, and LPIN collects the signal and transmits it to the microcontroller. When there is no phase loss in the three-phase power supply, capacitor C20 remains at a high level, ensuring continuous operation of the optocoupler. After passing through the filtering circuit, a low-level output is maintained, causing LED10 to remain constantly lit. The microcontroller collects the continuous low level via the LPIN to determine that there is no phase loss. When one phase is missing, capacitor C20 is in a discharging state within a 120° range. For 1 / 3 of the cycle, it cannot maintain the operation of the optocoupler. After passing through the filtering circuit, it is reflected that LED10 is off during this period due to a high level, while it remains lit during the remaining periods due to a low level, thus forming a pulse circuit. LED10 flashes, and the microcontroller collects the waveform circuit pulse or waveform duty cycle via the LPIN to determine the phase loss. When two or three phases are missing, an effective circuit cannot be formed to charge capacitor C20, causing the optocoupler to fail. Capacitor C21 receives no current and remains at a high level, causing LED10 to remain off. The microcontroller cannot collect the current wave via the LPIN, thus determining that there is a phase loss.

[0036] Advantages of this module: It only requires one optocoupler element to operate, is less expensive, and requires a smaller installation space.

[0037] like Figure 3As shown, the phase sequence protection circuit includes resistors R46 and R50. One end of resistor R46 is connected to the three-phase power input port W, and the other end of resistor R46 is connected to pin 4 of AC-DC converter module U11 via capacitor C22. One end of resistor R47 and one end of resistor R49 are connected to the three-phase power input port V, and the other end of resistor R47 is connected to pin 4 of AC-DC converter module U11. The other end of resistor R49 is connected to pin 3 of AC-DC converter module U11 via capacitor C24. One end of resistor R50 is connected to the three-phase power input port U, and the other end of resistor R50 is connected to pin 3 of AC-DC converter module U11.

[0038] Pin 1 of U11 is connected to the positive terminal of the LED in optocoupler U10 via resistor R48, and pin 2 of U11 is connected to the negative terminal of the LED in optocoupler U10. One end of capacitor C25 is connected to pin 1 of U11, and the other end of capacitor C25 is connected to pin 2 of U11. Pin 2 of U11 is grounded. One end of resistor R24 ​​is connected to pin 1 of U11, and the other end of resistor R24 ​​is connected to pin 2 of U11. One end of resistor R37 is connected to the positive terminal of the LED in U10, and the other end of resistor R37 is connected to the negative terminal of the LED in U10.

[0039] The phototransistor of optocoupler U10 has four collectors. The first collector is connected to a 5V power supply via resistor R45. The second collector is connected to a 5V power supply via LED11 and resistor R21. The third collector is grounded via capacitor C23. The fourth collector is connected to the corresponding pin of the microcontroller control unit. The emitter of the phototransistor of optocoupler U10 is grounded.

[0040] Its working principle is as follows: Phases U, V, and W are connected to resistors R46, R47, R49, and R50 respectively to achieve voltage reduction. Phase W is connected to capacitor C22 (CBB), and phase V is connected to capacitor C24 (CBB), leading or lagging the AC current by a certain angle. Then, rectifier bridge U11 converts the AC current to DC current, charging capacitor C25. The DC current is then stepped down by resistors R24, R48, and R37 to power optocoupler U11. After passing through a filter circuit composed of parallel capacitor C23, LED11 reflects the power waveform, and EP collects the signal and sends it to the microcontroller. (Input phase sequence and circuit principle) Figure 1When the phase sequence is correct, capacitor C25 stores a constant voltage, LED11 remains on, and optocoupler U11 continues to operate. After passing through the filtering circuit, a low-level output is generated, causing LED10 to remain on. The microcontroller collects this continuous low-level signal via EP to determine that the phase sequence is correct. If two phases are swapped (i.e., the phase sequence is reversed), the AC power connected to C22 and C24 cancels each other out due to their leading or lagging relationship. Capacitor C25 cannot charge, preventing optocoupler U11 from operating. The indicator light does not illuminate, and EP generates a high-level signal, indicating a phase sequence error. The microcontroller then sends a signal to the intelligent voice broadcast module to report the phase sequence installation problem.

[0041] This circuit can also determine the phase sequence. When phase U or W is missing, EP remains at a high 5V level and no waveform is output; when phase V is missing, a half-sine wave is output. Requirement: The phase sequence must match the encoder's phase sequence; otherwise, reverse operation will occur, the limit switch cannot be implemented, and a reverse operation alarm will sound. Advantages of this module: It only requires one optocoupler to operate and can determine the phase sequence. When used with an encoder, it achieves the following effect: workers do not need to determine the phase sequence and can connect wires arbitrarily.

[0042] Furthermore, such as Figure 4 As shown, the commutation circuit includes interfaces J1-J3. Interface J1 is the mains input and includes T, S, and R pins. Then, the input terminals of relays KP1-KP5 are connected. All relays are powered by +12VB. One end of relays KP1 and KP2 is connected to the JDQB node, and one end of relay KP3 is connected to the JDQC node. One end of relays KP4 and KP5 is connected to the JDQA node, and the other end is controlled by contact 5 to control the circuit. The output terminal is connected to the control box of interface J2 to supply power to the motor. Interface J2 includes U, W, and V pins.

[0043] Furthermore, such as Figure 4 As shown, it also includes a commutation circuit control logic circuit. The relay control signal comes from the microcontroller control unit. The microcontroller control unit pins MCUB and MCUA, MCUB and MCUA, have an internal interlock signal. The control logic circuit includes resistors R5-R7. One end of resistor R5 is connected to the MCUB pin, and the other end of resistor R5 is connected to the base of transistor Q2. The emitter of transistor Q2 is grounded. The collector of transistor Q2 is divided into three paths. The first path is connected to the +12V power supply through the reverse diode D4. The second path is connected to the +12V power supply after passing through the green light-emitting diode LED2 and resistor R8. The third path is the relay control node JDQB.

[0044] One end of resistor R6 is connected to the MCUA pin, and the other end of resistor R6 is connected to the base of transistor Q3. The emitter of transistor Q3 is grounded, and the collector of transistor Q3 is divided into three paths. The first path is connected to the +12V power supply through the reverse diode D5. The second path is connected to the +12V power supply after passing through the red light-emitting diode LED3 and resistor R9. The third path is the relay control node JDQA.

[0045] One end of resistor R7 is divided into two paths. The first path is connected to the MCUA pin via diode D7, and the second path is connected to the MCUB pin via diode D8. The other end of resistor R7 is connected to the base of transistor Q4. The emitter of transistor Q4 is grounded. The collector of transistor Q4 is divided into three paths. The first path is connected to the +12V power supply via reverse diode D6. The second path is connected to the +12V power supply via orange LED4 and resistor R10. The third path is connected to the relay control node JDQC.

[0046] In the relay group commutation circuit module, one end of the relay's output port is connected to the power supply, and the other end is connected to the motor body. The relay's control port is connected to the microcontroller system. Specifically, J1 is the AC power input, J2 is the control box output supplying power to the motor body, and J3 is the neutral (N) line, which provides protection and is installed on the fence terminal.

[0047] Its working principle is as follows: The microcontroller control unit uses two interlocked output pins, MCUA and MCUB (internal interlock signals, meaning only one can be high and the other low at any given time), to keep two of the pins JDQA, JDQB, and JDQC at a low level (JDQC must be low, and one of JDQA and JDQB must be low). At this time, relay KP3 closes the switch, and relays KP1 and KP2 close as a group (JDQB is low at this time; when JDQA is low, RY1 and RY2 are closed). In this case, U<->R, T<->W / S<->V. Similarly, in another case (when JDQA and JDQC are low), U<->R, T<->V / S<->W. This achieves motor commutation. To prevent issues such as relay sparking during commutation, this design uses a program-based delay control, with a delay of 2-5 seconds before commutation.

[0048] The advantages of this module are that the relay is cheaper than a dedicated three-phase relay, has a smaller physical size, and is easily integrated into the circuit board to achieve operation. It eliminates the need for a physical distribution box and avoids issues such as physical commutation and reverse sequence. Microcontroller-controlled delays can significantly improve the relay's performance and reliability. Requirement: The U, V, W phase sequence of the output terminal J2 must be the same as the motor's phase sequence.

[0049] like Figure 5As shown, the power supply system circuit includes a transformer module and a voltage regulator module. The transformer module includes a transformer DB1. Pin 1 of the transformer DB1 is connected to the W phase power supply via a fuse F1. Pin 5 of the transformer DB1 is connected to the V phase power supply. Pin 7 of the transformer DB1 is divided into four paths via a diode D1 and a resistor R23. The first path is grounded via a capacitor C1, the second path is grounded via a TV1, the third path is connected to the +12VB power output terminal via a diode D2, and the fourth path is the +12V power output terminal.

[0050] The voltage regulator module includes an LM2596-5V chip U3. Pin 1 of U3 is connected to the +12V power output of the transformer module. Pins 3 and 5 of U3 are grounded. Capacitors E2, E6, and C2 are connected in parallel between pins 1 and 3 of U3. Pin 2 of U3 is connected to one end of inductor L1 and inductor L2. The anode of diode D3 is grounded, and the cathode of diode D3 is connected to pin 2 of U3. One end of capacitor E3 and one end of capacitor C3 are grounded. The other ends of capacitor E3, capacitor C3, and pin 4 of U3 are connected to the junction between inductors L1 and L2. The other end of inductor L2 is divided into four paths: the first path is grounded through capacitor E4, the second path is grounded through capacitor C50, the third path is the +5V power output, and the fourth path is connected to the anode of diode D12. The cathode of diode D12 is divided into five paths, the first path being V5B. At the power output terminal, the second path is grounded via capacitor C7, the third path via capacitor C4, the fourth path via capacitor C5, and the fifth path via capacitor E5. The V5B power output terminal is divided into three paths after passing through resistor RP1: the first path is grounded via Zener diode U9, the second path is grounded via capacitor CD1, and the third path is the 2.5V power output terminal.

[0051] The power supply system module's input terminal is connected to two phases of the power supply, and its output terminal provides DC power to the microcontroller system. Its working principle is as follows: two phases of the three-phase power supply (U, V, W) are input, and the voltage is reduced to 12V through a wound transformer, then regulated by the ML2596 voltage regulator chip. The voltage regulator module stabilizes the 12V portion at 5V (some modules require 5V DC power).

[0052] The advantages of this module are that it replaces the traditional switching power supply, making the converted DC power more stable and less prone to damage. In agricultural fields, the voltage of three-phase AC power is unstable, reaching up to 720V when the voltage is superimposed. While a typical switching power supply can only withstand a maximum of 600V, this module uses a wound-rotor transformer to step down the AC power to a maximum of 24V, and then uses the ML2592 chip for voltage regulation. The ML2596 chip can withstand a maximum voltage of 56V or 60V, thus making the entire module less susceptible to damage. Simultaneously, the E5 farad capacitor enables the system to have a power-off memory function, resulting in more accurate control. When the motor suddenly loses power during operation, it will continue running for 1-2 seconds due to inertia. The E5 farad capacitor supplies power to the microcontroller system and the magnetic encoder module, allowing them to read and save the position signal of the motor after the power-off inertial motion.

[0053] like Figure 6 As shown, the intelligent voice broadcasting circuit includes a voice chip KT148. Its working principle is as follows: the microcontroller control unit sends commands to the voice chip KT148 via a communication circuit or button module, causing it to emit different sounds through the speaker (mainly including forward, backward, setting, alarm, etc.). For example, phase sequence and phase loss protection are provided above; when such events occur, the intelligent broadcasting system will prompt the user with a phase sequence error or phase loss protection voice to avoid more serious disasters. In setting mode, the intelligent broadcasting system will prompt successful setting of functions such as start and end points. During normal operation, it will prompt forward, backward, and over-limit alarm information.

[0054] like Figure 7 As shown. Left-side button circuit: The three buttons KEYUP, KEYDN, and KEYSP are grounded through capacitors C14, C15, and C16 respectively, and connected to the V5B power supply through series resistors R19, R18, and R17. Each button is also connected to the corresponding pin of the button interface P3 through series resistors R43, R40, and R26.

[0055] Right-side button circuit: includes three buttons S1-S3. One end of button S1 is grounded, and the other end of button S1 is divided into two paths. The first path is connected to a 5V power supply after passing through LED7 and resistor R25 in sequence. The second path is connected to the KEYUP pin in the microcontroller.

[0056] One end of the button S2 is grounded, and the other end of the button S2 is divided into two paths. The first path is connected to a 5V power supply after passing through an LED8 and a resistor R38 in sequence, and the second path is connected to the KEYDN pin in the microcontroller.

[0057] One end of the button S3 is grounded, and the other end of the button S3 is divided into two paths. The first path passes through the light-emitting diode LED9 and the resistor R42 in sequence and is connected to the 5V power supply. The second path is connected to the KEYSP pin in the microcontroller.

[0058] One end of the button module is connected to the microcontroller control unit, and the other end is connected to the physical buttons. Its working principle is as follows: the microcontroller system reads the state of the physical buttons through the I / O port; when a physical button is pressed (forward, backward, position setting), the microcontroller controls the corresponding module to perform the operation.

[0059] Instructions for using button limit settings:

[0060] 1. Connect the three 380V power cords.

[0061] 2. Press and hold the stop button to power on the motor. The motor will announce "Setup Mode" via voice. Release the stop button. The motor will emit a beeping sound at 3-second intervals. This indicates that it has entered setup mode.

[0062] 3. Press the forward or backward button to rotate the motor to the desired limit position, then press the stop button. Press and hold the stop button again, and simultaneously press the forward button. The motor will announce "End point set successfully." This indicates that a limit point has been set.

[0063] 4. Press the forward or backward button again to rotate the motor to the second position where the limit needs to be set, then press the stop button. Press and hold the stop button again, and simultaneously press the backward button. The motor will announce "Start point set successfully." This indicates that the second limit point has been set.

[0064] 5. When the motor is powered off, it will automatically exit the setting mode after five seconds. At this time, the set limit switches can be used normally.

[0065] like Figure 8 As shown, the remote control circuit includes a wireless module Wireless1. Pin 1 of the wireless module Wireless1 is grounded, pin 4 is connected to a +5V power supply to provide operating power for the module, pins 2 and 3 are shorted, and pin 2 is connected to a resistor R3. The other end of R3 is connected to pin 13 of the microcontroller.

[0066] One end of the remote control module is connected to the microcontroller system, and the other end communicates wirelessly with the remote control.

[0067] Its working principle is as follows: the remote control sends commands via buttons, the remote control module receives the commands and transmits them to the microcontroller system, which then performs the corresponding operations. For example, the remote control buttons can be used to control forward and reverse rotation, stop the operation, and set parameters; the pairing key enters the parameter setting mode.

[0068] Remote control limit setting instructions

[0069] 1. Connect the three 380V power cords.

[0070] 2. Press and hold the remote control pairing button without releasing it, then power on the motor. A beep will indicate successful remote control pairing. At this point, disconnect the power to the motor.

[0071] 3. After a five-second power outage, press and hold the pairing button on the remote control while powering on the motor. The motor will announce "Setup Mode" via voice. Release the pairing button. The motor will then emit a beeping sound at 3-second intervals. This indicates that the motor has entered setup mode.

[0072] 4. Press the forward or backward button to rotate the motor to the desired limit position, then press the stop button. Press and hold the stop button again, and simultaneously press the forward button. The motor will announce "End point set successfully." This indicates that a limit point has been set.

[0073] 5. Press the forward or backward button again to rotate the motor to the second position where the limit needs to be set, then press the stop button. Press and hold the stop button again, and simultaneously press the backward button. The motor will announce "Start point set successfully." This indicates that the second limit point has been set.

[0074] 6. When the motor is powered off, it will automatically exit the setting mode after five seconds. At this time, the set limit switches can be used normally.

[0075] Once the limit switch records at both ends are completed, work can begin.

[0076] Its workflow is as follows: Three-phase power is supplied to the circuit board → The phase sequence determination system within the circuit board determines the current phase sequence → The control system determines the motor's rotation direction based on the phase sequence determination result → The relay receives a signal and the motor begins to rotate → The encoder calculates the angle based on the number of rotations → The control chip determines the limit travel position based on the encoder signal → When the position is reached, the control chip sends a signal to the relay to cut off the power → A voice announcement announces that the position has been reached and the motor has stopped. Simultaneously, commands can be inserted at any time while the motor is powered on, either via a remote control or the buttons on the curtain motor housing.

[0077] like Figure 9As shown, the position control magnetic encoder module includes an encoder chip U5. Pins 1 and 2 of U5 are connected to the power supply VDD. Pin 3 of U5 is the signal output terminal, and pin 4 of U5 is grounded. One end of capacitors C9 and C10 is connected to the power supply VDD, and the other end of capacitors C9 and C10 is grounded. Pin 5 of U5 is divided into two paths: the first path is grounded through resistor R8, and the second path is connected to the PRO pin of the microcontroller. Pin 6 of U5 is divided into two paths: the first path is connected to the power supply VDD through resistor R2, and the second path is connected to the SDA pin of the microcontroller. Pin 7 of U5 is divided into two paths: the first path is connected to the power supply VDD through resistor R1, and the second path is connected to the SCL pin of the microcontroller. Pin 8 of U5 is divided into two paths: the first path is connected to the power supply VDD through resistor R5, and the second path is connected to the CSN pin of the microcontroller.

[0078] Its working principle is as follows: the position control magnetic encoder module collects the number of motor revolutions by sensing a magnet. The collected pulses are transmitted to the microcontroller via communication and stored in the microcontroller's EPROM.

[0079] Advantages of this module: 1. Unrestricted starting point setting, avoiding the limitations imposed by mechanical limits on traditional equipment; 2. Simple starting point setting: only the start and end points need to be set, without considering direction. This eliminates the need for one worker adjusting mechanical limits on top of the equipment and another providing power underground; now only a remote control is required; 3. The microcontroller has a built-in storage function, storing 4096 points per revolution, with 100 points memorized at a time. In case of lost coordinates or power failure, the last memorized value can be retrieved to obtain the current position; 4. Employs a magnetic encoder, reducing environmental requirements; 5. Significantly increases assembly speed, improving efficiency by at least 500%.

[0080] like Figure 10 As shown, the mechanical limit module includes an upper limit detection circuit and a lower limit detection circuit. The upper limit detection circuit includes a light-emitting diode (LED5). The positive terminal of LED5 is connected to a +12V power supply. The negative terminal of LED5 is divided into two paths: the first path is connected to the positive terminal of the LED in optocoupler U4, and the second path is connected to one end of capacitor C10. The other end of capacitor C10 is divided into two paths: the first path is grounded through resistor R11, and the second path is connected to the negative terminal of the LED in U4. The emitter of the phototransistor in U4 is grounded, and the collector of the phototransistor in U4 is divided into three paths: the first path is grounded through capacitor C11, the second path is connected to the V5B power supply through resistor R12, and the third path is connected to the MUP node through resistor R13.

[0081] The lower limit detection circuit includes a light-emitting diode (LED) 6. The positive terminal of LED 6 is connected to a +12V power supply. The negative terminal of LED 6 is divided into two paths: the first path is connected to the positive terminal of the LED in optocoupler U5, and the second path is connected to one end of capacitor C12. The other end of capacitor C12 is divided into two paths: the first path is grounded through resistor R14, and the second path is connected to the negative terminal of the LED in U5. The emitter of the phototransistor in U5 is grounded, and the collector of the phototransistor in U5 is divided into three paths: the first path is grounded through capacitor C13, the second path is connected to the V5B power supply through resistor R15, and the third path is connected to the MDOWN node through resistor R16. In addition to the software limit, a mechanical limit is reserved. Once the mechanical limit is effective, the circuit will stop even if the software limit has not been executed properly.

[0082] like Figure 11 The diagram shown is a circuit schematic of the microcontroller control unit in the controller described in this embodiment of the present invention.

[0083] Power Supply and Reset: The MCU's VDD pin 9 is connected to the power supply, and VSS pin 7 is grounded. The V5B power supply is connected to the corresponding pins of the MCU through capacitors C6 and C8, serving as a filter. The NRST pin 4 is grounded through a reset circuit consisting of resistor R2 and capacitor C9, realizing the reset function.

[0084] External signal input: Multiple pins are used to receive external signals. For example, pin 1 of PD4 is connected to the BDAT signal (voice system); pins 2 and 3 of PD5 and PD6 are used for the AIN5 and AIN6 signals (position control magnetic encoder) input, respectively, and are also multiplexed with UART1_TX and UART1_RX; pins 17, 17, and 15 of PC7, PC6, and PC5 are connected to the KEYUP, KEYDN, and KEYSP button signals (button circuit); pin PC4 is connected to pin 5 of P4 (position control magnetic encoder). Pin 13 of PC3 is connected to radio R3 (remote control circuit).

[0085] PA3 pin 10 is connected to the LPIN signal (phase loss detection circuit), and PB4 and PB5 pins 12 and 11 are connected to the MDOWN and MUP hard limit detection signals, respectively.

[0086] Communication and debugging interface: PD1 pin 18 is used for debugging and connects to the IO3 port of the intelligent voice broadcast circuit.

[0087] Other functional pins: PD3 pin is connected to the AD_AMPC signal (backup current detection circuit); PD2 pin is connected to the phase sequence protection circuit.

[0088] The curtain-pulling motor described in this utility model adopts a magnetic encoder and chip control to convert the main shaft rotation information of the curtain-pulling motor into an electrical signal, achieving high-precision positioning and free travel. In addition to phase sequence judgment, a phase sequence protection function unit is also added, so workers can connect wires arbitrarily without judging the phase sequence, truly achieving foolproof installation and solving the installation safety problem. The self-developed linear power supply with power failure protection avoids the risks of switching power supplies, solves the problem of coordinate offset during power failure, and greatly reduces the failure rate.

Claims

1. A highly integrated, high-precision, and high-safety electronic limit curtain motor, comprising a motor body, characterized in that... It also includes: a motor controller, which controls the movement of the motor body; the motor controller includes a microcontroller control unit; a phase loss detection circuit bidirectionally connected to the microcontroller control unit to determine whether the motor body is missing a phase; a phase sequence protection circuit bidirectionally connected to the microcontroller control unit to determine whether the phase sequence of the motor body is incorrect; a commutation circuit bidirectionally connected to the microcontroller control unit to realize the commutation switching operation of the motor body; an intelligent voice broadcast circuit connected to the signal output terminal of the microcontroller control unit to emit voice signals under the control of the microcontroller control unit; a remote control circuit connected to the signal input terminal of the microcontroller control unit to receive wireless remote control signals and control the motor controller to execute corresponding commands; a button circuit connected to the signal input terminal of the microcontroller control unit for manually inputting control commands; a position control magnetic encoder module bidirectionally connected to the microcontroller control unit to collect the number of revolutions of the motor through a sensing magnet; a mechanical limit module bidirectionally connected to the microcontroller control unit to limit the position of the motor body; and a power supply system circuit connected to the power input terminal of the modules in the motor controller that require power to provide them with working power.

2. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The phase loss detection circuit includes resistors R27-R32. One end of resistor R27 is connected to the three-phase power input port U, and the other end of resistor R27 is connected to pin 3 of switching diode DL1 via resistor R28. Pin 2 of DL1 is connected to one end of capacitor C20, and pin 1 of DL1 is connected to the other end of capacitor C20. One end of resistor R29 is connected to the three-phase power input port V, and the other end of resistor R29 is connected to pin 3 of switching diode DL2 via resistor R30. Pin 2 of DL2 is connected to one end of capacitor C20, and pin 1 of DL2 is connected to the other end of capacitor C20. One end of resistor R31 is connected to the three-phase power input port W, and the other end of resistor R31 is connected to pin 3 of switching diode DL3 via resistor R32. Pin 2 of DL3 is connected to one end of capacitor C20, and pin 1 of DL3 is connected to the other end of capacitor C20. One end of capacitor C20 is connected to the positive terminal of the LED of optocoupler U6 via resistor R34, and the other end of capacitor C20 is connected to the negative terminal of the LED of optocoupler U6. One end of resistor R33 is connected to the negative terminal of the LED of optocoupler U6, and the other end of resistor R33 is connected to the junction of resistor R34 and capacitor C20. One end of resistor R35 is connected to the negative terminal of the LED of optocoupler U6, and the other end of resistor R35 is connected to the positive terminal of the LED of optocoupler U6. The collector of the phototransistor in the optocoupler U6 is divided into four paths. The first path is connected to a 5V power supply via resistor R36. The second path is connected to a 5V power supply via LED10 and resistor R20. The third path is grounded via capacitor C21. The fourth path is connected to the corresponding pin of the microcontroller control unit. The emitter of the phototransistor in the optocoupler U6 is grounded.

3. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The phase sequence protection circuit includes resistors R46 and R50. One end of resistor R46 is connected to the three-phase power input port W, and the other end of resistor R46 is connected to pin 4 of AC-DC converter module U11 via capacitor C22. One end of resistor R47 and one end of resistor R49 are connected to the three-phase power input port V, and the other end of resistor R47 is connected to pin 4 of AC-DC converter module U11. The other end of resistor R49 is connected to pin 3 of AC-DC converter module U11 via capacitor C24. One end of resistor R50 is connected to the three-phase power input port U, and the other end of resistor R50 is connected to pin 3 of AC-DC converter module U11. Pin 1 of U11 is connected to the positive terminal of the LED in optocoupler U10 via resistor R48, and pin 2 of U11 is connected to the negative terminal of the LED in optocoupler U10. One end of capacitor C25 is connected to pin 1 of U11, and the other end of capacitor C25 is connected to pin 2 of U11. Pin 2 of U11 is grounded. One end of resistor R24 ​​is connected to pin 1 of U11, and the other end of resistor R24 ​​is connected to pin 2 of U11. One end of resistor R37 is connected to the positive terminal of the LED in U10, and the other end of resistor R37 is connected to the negative terminal of the LED in U10. The phototransistor of optocoupler U10 has four collectors. The first collector is connected to a 5V power supply via resistor R45. The second collector is connected to a 5V power supply via LED11 and resistor R21. The third collector is grounded via capacitor C23. The fourth collector is connected to the corresponding pin of the microcontroller control unit. The emitter of the phototransistor of optocoupler U10 is grounded.

4. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The commutation circuit includes interfaces J1-J3. Interface J1 is the AC power input and includes T, S, and R pins. Then, it connects to the input terminals of relays KP1-KP5. All relays are powered by +12VB. One end of relays KP1 and KP2 is connected to the JDQB node, and one end of relay KP3 is connected to the JDQC node. One end of relays KP4 and KP5 is connected to the JDQA node, and the other end is controlled by contact 5 to switch the circuit on and off. The output terminal is connected to the control box of interface J2 to supply power to the motor. Interface J2 includes U, W, and V pins. It also includes a commutation circuit control logic circuit. The relay control signal comes from the microcontroller control unit. The microcontroller control unit pins MCUB and MCUA, MCUB and MCUA, have an internal interlock signal. The control logic circuit includes resistors R5-R7. One end of resistor R5 is connected to the MCUB pin, and the other end of resistor R5 is connected to the base of transistor Q2. The emitter of transistor Q2 is grounded. The collector of transistor Q2 is divided into three paths. The first path is connected to the +12V power supply through the reverse diode D4. The second path is connected to the +12V power supply after passing through the green light-emitting diode LED2 and resistor R8. The third path is the relay control node JDQB. One end of resistor R6 is connected to the MCUA pin, and the other end of resistor R6 is connected to the base of transistor Q3. The emitter of transistor Q3 is grounded, and the collector of transistor Q3 is divided into three paths. The first path is connected to the +12V power supply through the reverse diode D5. The second path is connected to the +12V power supply after passing through the red light-emitting diode LED3 and resistor R9. The third path is the relay control node JDQA. One end of resistor R7 is divided into two paths. The first path is connected to the MCUA pin via diode D7, and the second path is connected to the MCUB pin via diode D8. The other end of resistor R7 is connected to the base of transistor Q4. The emitter of transistor Q4 is grounded. The collector of transistor Q4 is divided into three paths. The first path is connected to the +12V power supply via reverse diode D6. The second path is connected to the +12V power supply via orange LED4 and resistor R10. The third path is connected to the relay control node JDQC.

5. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The power supply system circuit includes a transformer module and a voltage regulator module. The transformer module includes a transformer DB1. Pin 1 of the transformer DB1 is connected to the W-phase power supply via a fuse F1. Pin 5 of the transformer DB1 is connected to the V-phase power supply. Pin 7 of the transformer DB1 is divided into four paths via a diode D1 and a resistor R23. The first path is grounded via a capacitor C1, the second path is grounded via a TV1, the third path is connected to the +12VB power output terminal via a diode D2, and the fourth path is the +12V power output terminal. The voltage regulator module includes an LM2596-5V chip U3. Pin 1 of U3 is connected to the +12V power output of the transformer module. Pins 3 and 5 of U3 are grounded. Capacitors E2, E6, and C2 are connected in parallel between pins 1 and 3 of U3. Pin 2 of U3 is connected to one end of inductor L1 and inductor L2. The positive terminal of diode D3 is grounded, and the negative terminal of diode D3 is connected to pin 2 of U3. One end of capacitor E3 and one end of capacitor C3 are grounded. The other ends of capacitor E3, the other end of capacitor C3, and pin 4 of U3 are connected to the junction between inductor L1 and inductor L2. The other end of the inductor L2 is divided into four paths: the first path is grounded through capacitor E4, the second path is grounded through capacitor C50, the third path is the +5V power output terminal, and the fourth path is connected to the positive terminal of diode D12. The negative terminal of diode D12 is divided into five paths: the first path is the V5B power output terminal, the second path is grounded through capacitor C7, the third path is grounded through capacitor C4, the fourth path is grounded through capacitor C5, and the fifth path is grounded through capacitor E5. The V5B power output terminal is divided into three paths after passing through resistor RP1: the first path is grounded through Zener diode U9, the second path is grounded through capacitor CD1, and the third path is the 2.5V power output terminal.

6. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The intelligent voice broadcasting circuit includes a voice chip KT148.

7. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The remote control circuit includes a wireless module Wireless1. Pin 1 of Wireless1 is grounded, pin 4 is connected to a +5V power supply to provide operating power for the module, pins 2 and 3 are shorted, and pin 2 is connected to a resistor R3. The other end of R3 is connected to pin 13 of the microcontroller.

8. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The button circuit includes three buttons S1-S3. One end of button S1 is grounded, and the other end of button S1 is divided into two paths. The first path passes through LED7 and resistor R25 in sequence and is connected to a 5V power supply. The second path is connected to the KEYUP pin in the microcontroller. One end of the button S2 is grounded, and the other end of the button S2 is divided into two paths. The first path is connected to a 5V power supply after passing through an LED8 and a resistor R38 in sequence, and the second path is connected to the KEYDN pin in the microcontroller. One end of the button S3 is grounded, and the other end of the button S3 is divided into two paths. The first path passes through the light-emitting diode LED9 and the resistor R42 in sequence and is connected to the 5V power supply. The second path is connected to the KEYSP pin in the microcontroller.

9. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The position control magnetic encoder module includes an encoder chip U5. Pins 1 and 2 of U5 are connected to the power supply VDD. Pin 3 of U5 is the signal output terminal, and pin 4 of U5 is grounded. One end of capacitors C9 and C10 is connected to the power supply VDD, and the other end of capacitors C9 and C10 is grounded. Pin 5 of U5 is divided into two paths: the first path is grounded through resistor R8, and the second path is connected to the PRO pin of the microcontroller. Pin 6 of U5 is divided into two paths: the first path is connected to the power supply VDD through resistor R2, and the second path is connected to the SDA pin of the microcontroller. Pin 7 of U5 is divided into two paths: the first path is connected to the power supply VDD through resistor R1, and the second path is connected to the SCL pin of the microcontroller. Pin 8 of U5 is divided into two paths: the first path is connected to the power supply VDD through resistor R5, and the second path is connected to the CSN pin of the microcontroller.

10. The highly integrated, high-precision, and high-safety electronic limit curtain motor as described in claim 1, characterized in that: The mechanical limit module includes an upper limit detection circuit and a lower limit detection circuit. The upper limit detection circuit includes a light-emitting diode (LED5). The positive terminal of LED5 is connected to a +12V power supply. The negative terminal of LED5 is divided into two paths: the first path is connected to the positive terminal of the LED in optocoupler U4, and the second path is connected to one end of capacitor C10. The other end of capacitor C10 is divided into two paths: the first path is grounded through resistor R11, and the second path is connected to the negative terminal of the LED in U4. The emitter of the phototransistor in U4 is grounded, and the collector of the phototransistor in U4 is divided into three paths: the first path is grounded through capacitor C11, the second path is connected to the V5B power supply through resistor R12, and the third path is connected to the MUP node through resistor R13. The lower limit detection circuit includes a light-emitting diode (LED) 6. The positive terminal of LED 6 is connected to a +12V power supply. The negative terminal of LED 6 is divided into two paths: the first path is connected to the positive terminal of the LED in optocoupler U5, and the second path is connected to one end of capacitor C12. The other end of capacitor C12 is divided into two paths: the first path is grounded through resistor R14, and the second path is connected to the negative terminal of the LED in U5. The emitter of the phototransistor in U5 is grounded, and the collector of the phototransistor in U5 is divided into three paths: the first path is grounded through capacitor C13, the second path is connected to the V5B power supply through resistor R15, and the third path is connected to the MDOWN node through resistor R16.

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