Reliability control circuit and method suitable for visual function training device

Abstract

The invention relates to a reliability control circuit and method suitable for a visual function training device, and belongs to the technical field of power supply anti-interference control. The circuit comprises a combined power supply separation and dynamic current limiting control circuit which is arranged in a power supply path shared by a communication module and an LED lamp panel and is used for suppressing transient current impact generated when the communication module is started; and the current self-feedback regulation circuit is arranged between the main control module and the LED lamp panel and is used for dynamically stabilizing the light output of the LED lamp panel under the driving of the rhythmic high-frequency PWM. When a part of lamp groups are detected to be invalid, the system can automatically enhance the output of adjacent areas, so that class proportion compensation is realized, and the light stimulation uniformity and the training continuity are guaranteed. According to the invention, real-time sensing and adjustment of abnormal states such as sudden increase of starting current of the 4G communication module, LED light decay or damage and the like are realized, and the stability and uniformity of light output and the reliability of long-term operation of the system are ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power anti-interference control, and relates to a reliability control circuit and method suitable for a visual function training device with an Internet of Things function. BACKGROUND

[0002] Visual function training devices, especially devices for intervening in problems such as accommodation lag and refractive abnormalities of adolescents, generally use light-emitting diode (LED) lamp panels as light sources to achieve the training purpose through output of rhythmic light stimulation. In such devices, in order to accurately control the frequency and intensity of light stimulation, pulse width modulation (PWM) technology is usually used to drive the LED at a high frequency. However, such high-frequency switching operation will generate electromagnetic interference (EMI) and instantaneous voltage pullback effect in the circuit, directly affecting the brightness stability of the LED, thereby reducing the accuracy of the training effect.

[0003] In addition, in order to realize remote data synchronization and control, modern visual function training devices often integrate 4G, Wi-Fi and other Internet of Things communication modules. Such communication modules, especially 4G modules, will generate a surge current as high as 2A or even higher at the moment of power-on start. Such transient large current will cause a huge impact on the main power supply bus of the system, easily causing a sharp drop in system voltage, which may not only cause the main control chip to work abnormally, but also may cause permanent damage to the main control unit or the LED lamp panel.

[0004] At present, the existing control circuit schemes in the industry also have limitations. Most schemes rely on software level to adjust the light and judge the fault of the lamp group, and lack hardware-level synchronous sampling and dynamic compensation mechanism for key parameters such as actual working voltage and current of the LED. This leads to difficulty in ensuring the uniformity of light intensity output when multiple channels of LED are working at the same time. Especially in the case of failure of light decay or damage of part of the LED lamp beads, the traditional circuit cannot perform real-time fault tolerance control or power compensation, thereby destroying the uniformity of light stimulation and the continuity of the training task, and affecting the consistency of the overall treatment effect.

[0005] Therefore, there is an urgent need in the field for a new control circuit structure that can solve the above problems from the hardware level, not only has strong anti-interference ability to cope with the impact of high-frequency driving and module start, but also integrates a fault self-recovery function, thereby comprehensively improving the power supply stability, light output consistency and long-term reliability of the visual function training device. SUMMARY

[0006] In view of this, the purpose of this invention is to provide a reliability control circuit and method suitable for visual function training devices, solving the problems of unstable light intensity, training interruption, or device damage caused by electromagnetic interference, transient surges, and power impacts between modules in existing LED driving systems during rhythmic PWM control. By constructing a composite circuit structure integrating surge protection, analog error feedback adjustment, and power partitioning compensation, real-time sensing and adjustment of abnormal states such as sudden increases in communication module startup current, LED light decay, or damage are achieved, ensuring the stability and uniformity of light output and the long-term reliability of the system.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] Option 1:

[0009] A reliability control circuit is provided for a visual function training device, which includes a power supply module, a communication module, a main control module, and an LED light board. The power supply module supplies power to the communication module, the main control module, and the LED light board. The main control module is connected to the communication module and the LED light board via signals. The control circuit includes a combined power isolation and dynamic current limiting control circuit and a current self-feedback adjustment circuit.

[0010] The combined power isolation and dynamic current limiting control circuit is set in the power supply path shared by the communication module and the LED light board to suppress transient current surges generated when the communication module starts up.

[0011] The current self-feedback regulation circuit is located between the main control module and the LED light board, and is used to dynamically stabilize the light output of the LED light board under rhythmic high-frequency PWM drive.

[0012] Preferably, the combined power isolation and dynamic current limiting control circuit includes:

[0013] Surge isolation zones are set in the shared power supply path of the LED light panel and the communication module to provide a physical power barrier;

[0014] A π-shaped filter network, connected in series in the main power supply path, is used to filter out high-frequency spike interference signals; and

[0015] The low-side current sampling and overvoltage clamping protection circuit is located on the ground wire of the LED driver channel to detect transient high currents and provide surge absorption protection.

[0016] Preferably, the surge isolation region includes an isolation MOS switch (Q1), a switching diode (D2), and a current-limiting resistor (R1), which can provide intermittent buffering when the communication module starts up, preventing it from pulling down the power supply bus voltage; the source of the isolation MOS switch (Q1) is connected to the communication module, the gate is connected to the low-side current sampling and overvoltage clamping protection circuit, and the drain is connected to the π-shaped filter network.

[0017] Preferably, the π-shaped filter network includes an inductor (L1), a first capacitor (C1), and a second capacitor (C2); one end of the inductor (L1) is connected to the power supply module, and the other end is connected to the low-side current sampling and overvoltage clamping protection circuit; one end of the first capacitor (C1) is connected to one end of the inductor (L1), and the other end is grounded; one end of the second capacitor (C2) is connected to the other end of the inductor (L1), and the other end is grounded.

[0018] Preferably, the low-side current sampling and overvoltage clamping protection circuit includes a sampling resistor (Rs) and a transient voltage suppression (TVS) diode (D1); one end of the sampling resistor (Rs) is connected to the gate of the isolation MOS switch (Q1) in the surge isolation region, and the other end is connected to the output terminal of the transient voltage suppression (TVS) diode (D1) to convert the transient current into a voltage signal; the input terminal of the transient voltage suppression (TVS) diode (D1) is grounded to absorb instantaneous power surges.

[0019] Preferably, the current self-feedback regulation circuit is an analog PID control loop circuit, comprising:

[0020] The sampling feedback path is used to acquire the working voltage of the LED driver output terminal and convert it into a feedback voltage signal;

[0021] An error amplifier module (U1) is used to receive the feedback voltage signal and a preset reference voltage, and generate an error signal reflecting the brightness deviation; and

[0022] An analog PID controller is connected to the stage following the error amplifier module. It performs proportional-integral-derivative adjustment based on the error signal and outputs a control signal to drive the PWM modulator.

[0023] Preferably, the sampling feedback path uses high-resistance voltage divider resistors (R3, R4) to convert the LED operating voltage into a feedback voltage signal.

[0024] Preferably, the analog PID controller includes a proportional current-limiting resistor (R5), an integral capacitor (C1), and a fine-tuning derivative circuit (R6, C2, C3) connected in series to form a complete proportional-integral-derivative three-segment adjustment path.

[0025] Option 2:

[0026] A reliability control method for visual function training devices, implemented using the circuit described in Scheme 1, includes the following steps:

[0027] The combined power isolation and dynamic current limiting control circuit physically separates the power supply paths of the main control module and the communication module, suppressing the impact of current surges during communication module startup on the system power supply bus.

[0028] The current self-feedback regulation circuit acquires the multi-channel voltage of the LED driving channel in real time, generates an error signal, and drives the analog PID control loop to dynamically adjust the PWM duty cycle to achieve stable light output.

[0029] Furthermore, the method also includes a fault compensation step: when the current self-feedback adjustment circuit detects that some lamp groups have failed, the system can automatically enhance the output of adjacent areas to achieve local brightness ratio compensation, so as to ensure the uniformity of light stimulation and the continuity of training.

[0030] The beneficial effects of this invention are as follows:

[0031] (1) This solution constructs a current-limiting and anti-interference structure design for the impact of 4G communication startup: This solution sets up a local surge isolation area in the LED driving channel and integrates low-end current sampling, π-type filter network and high-speed TVS clamping transistor to form a synchronous current-limiting protection mechanism that adapts to the sudden change of large current (>2A) when the 4G communication module is powered on. This structure can effectively isolate the voltage pullback and interference of the LED power supply circuit caused by the transient startup of the communication module, prevent light decay, false triggering or device breakdown caused by voltage drop, and significantly improve the power supply stability and circuit anti-interference capability in rhythmic stimulation tasks.

[0032] (2) This solution provides a lamp board brightness and equalization adjustment mechanism based on simulated PID feedback: To reduce the computational burden on the main control unit, this invention introduces a simulated PID feedback circuit to collect the actual voltage of each lamp group and calculate the error signal. Compared with ordinary PID control, the simulated PID feedback circuit used in this invention has a faster response speed, stronger environmental adaptability, and higher system stability, making it particularly suitable for the strict requirements of real-time performance and light intensity equalization in multi-channel high-frequency light stimulation training devices. The duty cycle of the PWM signal is dynamically adjusted through proportional-integral-derivative adjustment logic to achieve stable control of lamp board brightness, frequency, and number of lamps lit. This structure has adaptive compensation capability. When lamp beads in a certain area are damaged or fail, the system can automatically increase the output current of adjacent areas to achieve local brightness ratio compensation, ensuring uniform overall light intensity distribution and maintaining the continuity and stability of the training task.

[0033] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0035] Figure 1 A framework diagram of the reliability control method for visual function training devices provided by the present invention;

[0036] Figure 2 Circuit diagram of a combined power supply isolation and dynamic current limiting control circuit;

[0037] Figure 3 This is a circuit diagram of a current self-feedback regulation circuit. Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0039] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0040] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0041] Please see Figure 1 This invention provides a reliability control circuit suitable for a visual function training device. The visual function training device includes a power supply module, a communication module, a main control module (such as a main control chip ESP32), and an LED light board. The power supply module supplies power to the communication module, the main control module, and the LED light board. The main control module is signal-connected to both the communication module and the LED light board. The control circuit includes:

[0042] A combined power isolation and dynamic current limiting control circuit is set in the power supply path shared by the communication module and the LED light board to suppress transient current surges generated when the communication module starts up.

[0043] A current self-feedback regulation circuit is set between the main control module and the LED light board to dynamically stabilize the light output of the LED light board under rhythmic high-frequency PWM drive.

[0044] Example 1:

[0045] This embodiment provides a design diagram of a combined power supply isolation and dynamic current limiting control circuit, such as... Figure 2 As shown, the circuit mainly includes a surge isolation zone, a π-shaped filter network, and a low-end current sampling and overvoltage clamping protection circuit.

[0046] (1) The surge isolation zone is formed by setting an isolation MOS switch Q1 in the power supply path shared by the LED light board and the 4G communication module, which, together with the current limiting resistor R1, constitutes a physical barrier against power surges. This structure can achieve millisecond-level intermittent buffering during the startup phase of the communication module, preventing it from pulling down the entire power supply bus. Specifically, the source of the isolation MOS switch Q1 is connected to the communication module, the gate is connected to the low-side current sampling and overvoltage clamping protection circuit, and the drain is connected to the π-type filter network.

[0047] (2) The π-shaped filter network consists of a series inductor L1 and two capacitors (C1, C2) to effectively filter out high-speed spike interference signals (>10MHz) and prevent radio frequency radiation during PWM driving from affecting the stability of the communication module. Specifically, one end of inductor L1 is connected to the power supply module, and the other end is connected to the low-side current sampling and overvoltage clamping protection circuit; one end of the first capacitor C1 is connected to one end of inductor L1, and the other end is grounded; one end of the second capacitor C2 is connected to the other end of inductor L1, and the other end is grounded.

[0048] (3) Low-end current sampling involves setting a precision sampling resistor Rs on the LED channel ground wire to convert transient high current into a sampling voltage signal for identification by the subsequent detection module. A TVS diode D1 is connected in series as a bidirectional overvoltage clamping device, capable of absorbing instantaneous power surges up to 600W within <1ns, protecting the LED driver circuit from overvoltage damage. Specifically, one end of the sampling resistor Rs is connected to the gate of the isolation MOS switch Q1 in the surge isolation region, and the other end is connected to the output terminal of the TVS diode D1, used to convert transient current into a voltage signal; the input terminal of the transient voltage suppression TVS diode D1 is grounded to absorb instantaneous power surges.

[0049] Example 2:

[0050] This embodiment provides a design diagram of a current self-feedback regulation circuit, see [link]. Figure 3 The circuit structure mainly includes:

[0051] (1) Sampling feedback path: A voltage sampling network is introduced at the output of each LED driver. High-resistance voltage divider resistors (R3, R4) are usually used to convert the LED working voltage into a processable feedback voltage signal and input it to the inverting terminal of the dual operational amplifier integrated circuit U1 (such as LM358DT).

[0052] (2) Error amplifier module: Set the voltage reference source Vref (such as 3.3V reference voltage) to the positive terminal of the dual operational amplifier integrated circuit U1, and form a difference error input with the actual feedback voltage. This error signal reflects the deviation between the current output brightness and the target brightness.

[0053] (3) The analog PID controller, after U1, consists of a proportional current-limiting resistor (R5), an integrating capacitor (C1), and a fine-tuning differential circuit (including the sixth resistor R6, the second capacitor C2, and the differential capacitor C3) connected in series to form a complete proportional-integral-derivative three-segment adjustment path. This structure directly performs real-time filtering and adjustment of the error signal at the hardware level, and the output control signal is used to drive the PWM modulator.

[0054] Compared with traditional digital PID control schemes, this circuit has a faster response time and the adjustment delay can be controlled within 10µs, making it suitable for high-frequency PWM output scenarios. It also eliminates the need for continuous computation by the main control chip, reducing its computational burden. It is suitable for visual stimulation control scenarios in vision training instruments that require high light intensity stability.

[0055] Specifically, the fourth resistor R4 is connected to the LED light board and the main control module respectively; one end of the third resistor R3 is connected to the LED light board, and the other end is connected to pin 3 of the dual operational amplifier integrated circuit U1 (i.e., the non-inverting input of the first op-amp); the fifth resistor R5 is connected in parallel with the third resistor R3; the two ends of the integrating capacitor C1 are connected to pin 2 (i.e., the inverting input of the first op-amp) and pin 7 (i.e., the output of the second op-amp) of the dual operational amplifier integrated circuit U1; the differentiating capacitor C3 is connected to pin 4 (i.e., the negative power supply input) and pin 7 (i.e., the output of the second op-amp) of the dual operational amplifier integrated circuit U1; pin 8 of the dual operational amplifier integrated circuit U1 is connected to the power supply module; the two ends of the sixth resistor R6 are connected to pin 7 (i.e., the output of the second op-amp) of the dual operational amplifier integrated circuit U1 and the main control module; one end of the second capacitor C2 is connected to the sixth resistor R6, and the other end is grounded.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A reliability control circuit suitable for a visual function training device, the visual function training device comprising a power supply module, a communication module, a main control module, and an LED light board, wherein the power supply module supplies power to the communication module, the main control module, and the LED light board; the main control module is signal-connected to the communication module and the LED light board, characterized in that, The control circuit includes: a combined power supply isolation and dynamic current limiting control circuit and a current self-feedback regulation circuit; The combined power isolation and dynamic current limiting control circuit is set in the power supply path shared by the communication module and the LED light board to suppress transient current surges generated when the communication module starts up. The current self-feedback regulation circuit is located between the main control module and the LED light board, and is used to dynamically stabilize the light output of the LED light board under rhythmic high-frequency PWM drive.

2. The reliability control circuit according to claim 1, characterized in that, The combined power isolation and dynamic current limiting control circuit includes: Surge isolation zones are set in the shared power supply path of the LED light panel and the communication module to provide a physical power barrier; A π-shaped filter network, connected in series in the main power supply path, is used to filter out high-frequency spike interference signals; and The low-side current sampling and overvoltage clamping protection circuit is located on the ground wire of the LED driver channel to detect transient high currents and provide surge absorption protection.

3. The reliability control circuit according to claim 2, characterized in that, The surge isolation region includes an isolation MOS switch (Q1), a switching diode (D2), and a current-limiting resistor (R1); the source of the isolation MOS switch (Q1) is connected to the communication module, the gate is connected to the low-side current sampling and overvoltage clamping protection circuit, and the drain is connected to the π-shaped filter network.

4. The reliability control circuit according to claim 2, characterized in that, The π-shaped filter network includes an inductor (L1), a first capacitor (C1), and a second capacitor (C2). One end of the inductor (L1) is connected to the power module, and the other end is connected to the low-side current sampling and overvoltage clamping protection circuit. One end of the first capacitor (C1) is connected to one end of the inductor (L1), and the other end is grounded. One end of the second capacitor (C2) is connected to the other end of the inductor (L1), and the other end is grounded.

5. The reliability control circuit according to claim 3, characterized in that, The low-side current sampling and overvoltage clamping protection circuit includes a sampling resistor (Rs) and a transient voltage suppressor diode (D1); one end of the sampling resistor (Rs) is connected to the gate of the isolation MOS switch (Q1) in the surge isolation zone, and the other end is connected to the output terminal of the transient voltage suppressor diode (D1) to convert transient current into a voltage signal; the input terminal of the transient voltage suppressor diode is grounded to absorb instantaneous power surges.

6. The reliability control circuit according to claim 1, characterized in that, The current self-feedback regulation circuit is an analog PID control loop circuit, including: The sampling feedback path is used to acquire the working voltage of the LED driver output terminal and convert it into a feedback voltage signal; An error amplifier module is used to receive the feedback voltage signal and a preset reference voltage, and generate an error signal reflecting the brightness deviation; and An analog PID controller is connected to the stage following the error amplifier module. It performs proportional-integral-derivative adjustment based on the error signal and outputs a control signal to drive the PWM modulator.

7. The reliability control circuit according to claim 6, characterized in that, The sampling feedback path uses a high-resistance voltage divider resistor to convert the LED operating voltage into a feedback voltage signal.

8. The reliability control circuit according to claim 6, characterized in that, The analog PID controller includes a proportional current-limiting resistor (R5), an integral capacitor, and a fine-tuning derivative circuit connected in series to form a complete proportional-integral-derivative three-segment adjustment path.

9. A reliability control method suitable for visual function training devices, characterized in that, This method is implemented using the circuit described in any one of claims 1 to 8, and includes the following steps: The combined power isolation and dynamic current limiting control circuit physically separates the power supply paths of the main control module and the communication module, suppressing the impact of current surges during communication module startup on the system power supply bus. The current self-feedback regulation circuit acquires the multi-channel voltage of the LED driving channel in real time, generates an error signal, and drives the analog PID control loop to dynamically adjust the PWM duty cycle to achieve stable light output.

10. The reliability control method according to claim 1, characterized in that, It also includes a fault compensation step: when the current self-feedback adjustment circuit detects that some lamp groups have failed, the system automatically enhances the output of adjacent areas to achieve local brightness ratio compensation, so as to ensure the uniformity of light stimulation and the continuity of training.

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