A flexible LED lamp panel circuit

Abstract

The utility model discloses a kind of flexible LED lamp panel circuits, comprising: isolated feedback control module A;LED pixel array module B;The isolated feedback control module A includes two parallelly connected photocoupler U3, U4, forms redundancy transmission channel;Power control ground PGND and logic ground GND, both physical isolation forms sub-area grounding structure;Transient suppression diode D7 and current-limiting resistor R29, R38 being set in the input end of the isolated feedback control module A, form protection circuit;Compensation network C20, C21 being set in the isolated feedback control module A, respectively arranged in master control side and secondary reference side;The LED pixel array module B includes multiple intelligent RGB lamp beads WS2812B-2020, and it is arranged in single line cascade mode;Multiple power injection points, along the LED pixel array module B distribution setting.This flexible LED lamp panel circuit has the characteristics of strong anti-interference ability, uniform and reliable power supply, stable signal transmission.

Description

Technical Field

[0001] This utility model relates to a flexible LED light board circuit, and in particular to a highly reliable intelligent RGB light strip circuit structure for use in scenarios where bending and attachment are possible. Background Technology

[0002] With the development of LED technology and the increasing demand for smart lighting, flexible LED light panels are widely used in decorative lighting, ambient lighting, wearable devices, and architectural lighting. Due to their bendable and attachable characteristics, flexible light panels free lighting applications from the constraints of traditional rigid circuit boards, allowing them to adapt to various complex curved surfaces and spatial environments.

[0003] Existing flexible LED light board circuits mainly fall into two technical categories: One approach uses a simple analog dimming driver circuit combined with ordinary RGB LED beads; the other uses intelligent LED chips such as the WS2812 series for single-point addressing control. These technologies each have their advantages and disadvantages, but in practical applications, they all face several common technical challenges: First, there's the issue of power supply stability. When powering long circuits on flexible circuit boards, the copper foil is relatively thin and has a relatively high resistance. When a large number of LEDs are working simultaneously, a significant voltage drop occurs, leading to insufficient brightness or color deviation in the distant LEDs. Traditional solutions include increasing the thickness or width of the copper foil, but this reduces the bending performance of the flexible board; or using single-point power supply to increase the current, but this increases local hotspots and power line losses.

[0004] Second, there's the issue of signal integrity. Intelligent RGB light panels use high-speed digital signal transmission, which is particularly prone to signal reflection, attenuation, and crosstalk at the bending points of the flexible board, leading to unstable control or failure of distant pixels to respond properly. Existing technologies mainly rely on increasing driving capability or reducing transmission rate to solve this problem, but these methods either increase power consumption or reduce lighting effects.

[0005] Third, there is the issue of interference immunity. Flexible LED panels are typically installed in accessible environments, frequently subjected to electrostatic discharge (ESD) and electromagnetic interference (EMI). In existing technologies, the feedback control circuit and the LED load share the same grounding system, making it easy for high-current switching noise to couple into the control circuit, causing brightness flickering or control abnormalities. Especially when multiple smart LED chips switch states simultaneously, the resulting ground noise can severely affect feedback accuracy.

[0006] Fourth, reliability issues. In traditional flexible LED light panels, the feedback control system typically uses a single optocoupler for isolation and transmission. Due to the inherent characteristics of the optocoupler, the current transfer ratio (CTR) drifts during temperature changes and aging, leading to a decrease in control accuracy. In flexible application scenarios, this drift problem is even more pronounced because the device may be subjected to different bending states and temperature environments.

[0007] Therefore, there is an urgent need for a structurally optimized flexible LED light board circuit that can adapt to various bending and attachment scenarios, providing stable and uniform lighting effects and reliable control performance. Utility Model Content

[0008] The purpose of this invention is to provide a flexible LED light board circuit. This flexible LED light board circuit features strong anti-interference capability, uniform and reliable power supply, and stable signal transmission.

[0009] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a flexible LED light board circuit, comprising: an isolated feedback control module A; an LED pixel array module B; the isolated feedback control module A includes two optocouplers U3 and U4 connected in parallel to form a redundant transmission channel; power control ground PGND and logic ground GND are physically isolated to form a domain-specific grounding structure; transient suppression diode D7 and current limiting resistors R29 and R38 are disposed at the input terminal of the isolated feedback control module A to form a protection circuit; compensation networks C20 and C21 are disposed in the isolated feedback control module A and are respectively arranged on the main control side and the secondary reference side; the LED pixel array module B includes multiple intelligent RGB LED beads WS2812B-2020, arranged in a single-line cascade manner; multiple power injection points are distributed along the LED pixel array module B.

[0010] The present invention is further configured such that the LED sides of the optocouplers U3 and U4 are connected in parallel to receive the same signal source, and the transistor sides work together on the compensation terminal COMP node of the error amplifier.

[0011] The present invention is further configured such that: in the domain grounding structure, the power control ground PGND is used for power domain grounding, and the logic ground GND is used for signal domain grounding, and the two are connected only through an isolation device.

[0012] The present invention is further configured such that the transient suppression diode D7 and the current limiting resistors R29 and R38 in the protection circuit are arranged in front of the feedback signal path to form a protective barrier.

[0013] The present invention is further configured such that the data input terminal DIN and the data output terminal DOUT of the RGB lamp beads WS2812B-2020 in the LED pixel array module B are connected in series, while the power supply terminal VDD is connected in parallel.

[0014] The present invention is further configured such that the plurality of power injection points are distributed in such a way that one injection point is set every predetermined number of LED beads.

[0015] The present invention is further configured such that: the isolated feedback control module A and the LED pixel array module B form a hierarchical control architecture with distributed light-emitting end and centralized control end, and the control side accurately locks the bus voltage or brightness through unified isolated feedback.

[0016] In summary, this utility model has the following beneficial effects: The dual optocoupler parallel structure design improves the redundancy and linearity of the feedback signal, effectively reducing loop noise. Even if any optocoupler degrades or fails, the system can still maintain basic functionality, improving the reliability and lifespan of the flexible LED light board. The separate domain structure of power control ground PGND and logic ground GND effectively isolates power domain noise from the signal domain, reducing ground noise coupling by approximately 50%, making it particularly suitable for long traces and bending applications on flexible boards, thus improving loop immunity. The front-end protection circuit, composed of transient suppression diode D7 and current-limiting resistors R29 and R38, effectively defends against ESD impacts, protecting sensitive feedback control circuitry and improving the stability of the flexible light board in environments with frequent contact and installation. A distributed compensation network design, with compensation capacitors C20 and C21 placed on the main control side and secondary reference side respectively, optimizes the loop phase-frequency characteristics, ensuring stable operation of the flexible board under various load conditions. By employing a high-density, single-line cascaded arrangement and small-sized intelligent RGB LEDs, multiple independent LEDs can be controlled with just three wires, greatly simplifying wiring complexity and allowing the flexible board to achieve a smaller bending radius. A multi-point power injection structure is used, with a power injection point set at regular intervals between LEDs, effectively solving the problem of voltage drop over long links and ensuring color consistency throughout the entire length of the light strip. A tightly coupled data and ground trace structure ensures the integrity of high-speed data signals, reduces reflection and radiation, and guarantees the continuity of the signal return path even at bends in the flexible board. The overall design forms a hierarchical control architecture with distributed light emission and centralized control. Unified isolation feedback precisely locks the bus voltage or brightness, supports lengthening / cutting, and improves product compatibility and applicability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the isolated feedback control module of this utility model; Figure 2This is a schematic diagram of the structure of the LED pixel array module of this utility model. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The technical solution of the present invention is not limited to the embodiments listed below.

[0019] like Figure 1 and Figure 2 As shown, this utility model discloses a flexible LED light board circuit, including an isolated feedback control module A and an LED pixel array module B.

[0020] The isolated feedback control module A is located at one end of the flexible circuit board and is used to provide stable voltage and brightness control; the LED pixel array module B is distributed along the flexible board and consists of multiple intelligent RGB LED beads WS2812B-2020 arranged in a single-line cascade manner.

[0021] The isolated feedback control module A employs a dual-optocoupler parallel structure, comprising two optocouplers, U3 and U4, connected in parallel. The LED side receives the same signal source in parallel, while the transistor side functions together at the compensation node (COMP) of the error amplifier. This parallel structure forms a redundant transmission path, effectively reducing the impact of individual optocoupler CTR drift and improving system reliability. When the output voltage or brightness exceeds the set value, the TL431's on-state current increases, leading to increased optocoupler LED current, enhanced optocoupler transistor conduction, and a pull-down of the COMP terminal, reducing the duty cycle; conversely, the effect is reversed, forming a closed-loop control.

[0022] This invention also employs a domain-based grounding structure design, physically isolating the power control ground PGND from the logic ground GND. PGND is used for power domain grounding to handle high-current switching noise; GND is used for signal domain grounding to ensure the integrity of control and data signals. The two are connected only through isolation devices, effectively blocking the transmission of power noise to the signal domain. This domain-based grounding structure is particularly suitable for long traces and bending applications on flexible boards, improving loop immunity.

[0023] At the input of the isolated feedback control module A, a transient suppression diode D7 and current-limiting resistors R29 and R38 are installed to form a front-end protection circuit. The transient suppression diode D7 absorbs external ESD or high-frequency spikes to ground, protecting the subsequent optocoupler LED and TL431 reference source. R29 and R38, as current-limiting resistors, limit the normal operating current and inrush current under abnormal conditions, ensuring the safe and stable operation of the feedback system.

[0024] To ensure the stability of the closed-loop system, this invention incorporates a distributed compensation network in the isolated feedback control module A, including capacitors C20 and C21, which are respectively located on the main control side and the secondary reference side. Capacitor C20 is situated at the COMP node, forming a dominant pole to suppress loop oscillations and high-frequency noise. Capacitor C21, along with associated resistors (e.g., resistors R47, R40, and R48), forms a compensation branch, ensuring loop stability and smooth startup. This distributed compensation structure adapts to the characteristics of isolated feedback systems, guaranteeing stable operation under various load conditions.

[0025] LED pixel array module B consists of multiple intelligent RGB LED beads, WS2812B-2020, arranged in a single-wire cascade configuration. The data input terminal DIN of each WS2812B-2020 is connected to the data output terminal DOUT of the preceding one, forming a series data path; while the power supply terminal VDD is connected to the power distribution network in parallel. This arrangement requires only three wires (power, ground, and data) to control multiple independent LEDs, greatly simplifying wiring complexity.

[0026] To address the voltage drop issue along long power lines, this invention employs a multi-point power injection structure, distributing multiple power injection points along LED pixel array module B, spaced at predetermined intervals (e.g., every 10 pixels). Figure 2 The voltage at the top left corner of the LED chip does not represent a 5V voltage injection for each chip; it is merely a repeating marker and can be set according to actual needs. Each LED chip has an injection point. This distributed power supply design effectively solves the problem of color shift caused by insufficient voltage in far-end pixels, ensuring brightness uniformity across the entire length.

[0027] To ensure the integrity of high-speed data signals in practice, this invention can also employ a tightly coupled routing structure for the data line and ground line. The data line and ground line are arranged in parallel, forming a complementary structure for signal and return current, ensuring a short and stable signal return path and reducing crosstalk and reflections at bends. This design ensures reliable signal transmission even when the signal is bent.

[0028] The isolated feedback control module A and LED pixel array module B of this invention form a hierarchical control architecture with distributed light-emitting end and centralized control end. On the load side, segmented power supply solves the voltage drop and heat generation problems, while on the control side, unified isolated feedback locks the bus voltage or brightness, forming a structure system friendly to flexible LED panels. This supports lengthening / cutting and on-site maintenance, improving product compatibility and applicability.

[0029] In practical applications, this invention can adjust parameters such as the number of RGB LED beads, the power injection point spacing, and the copper foil width according to specific needs to adapt to flexible LED light board applications with different lengths and bending requirements.

[0030] The present invention employs the following experiments to quantitatively test the technical effectiveness of the flexible LED light board circuit. 1. Using a comparative experiment method, the flexible LED light board of this utility model is compared with the traditional flexible light board with single optocoupler, common ground design and single-point power supply. Various working conditions in actual use environment are simulated and key performance data are collected.

[0031] 2. Technical Effects

[0032] 3. Verify the testing method Optocoupler redundancy test: One optocoupler is intentionally disabled; the system's ability to continue operating is measured. Feedback loop noise level and control accuracy changes are recorded. COMP terminal ripple is measured using a precision oscilloscope. Performance stability of different optocoupler configurations is tested under temperature cycling conditions (-20°C to 85°C).

[0033] Noise isolation test: Design a comparison board with two grounding schemes. Under the condition of alternating RGB full-on and full-off flashing (frequency 1Hz), measure the ground potential fluctuation and COMP terminal ripple of the feedback control circuit. At the same time, record the stability data of LED output brightness.

[0034] Brightness uniformity test: With all 60 LEDs lit in full white, a calibrated photometer was used to measure the brightness and color temperature every 10 LEDs along the length of the LED strip, and the maximum deviation value was recorded. At the same time, the voltage value at each point was measured and the percentage voltage drop was calculated.

[0035] Bending signal integrity test: The light board is bent to different radii (R=10mm, 20mm, 30mm), and the data signal quality at the bending point is measured, including rise time, jitter, and error rate. Simultaneously, a stability test is performed under long-term (48 hours) bending conditions.

[0036] 3. Verification Conclusion Comparative testing and verification have shown that the flexible LED light board circuit of this utility model has the following technical effects: The dual optocoupler parallel structure reduces feedback loop noise by 25% and maintains system functionality even when a single optocoupler fails; the PGND / GND domain design effectively isolates power domain noise and reduces ground noise coupling by 52%; the multi-point power injection structure keeps the brightness difference of the entire LED strip within 5%; and the tight-coupled routing and segmented decoupling design significantly improve signal integrity at bends and reduce distortion to below 7%.

[0037] In summary, this utility model provides a flexible lighting technology solution with high reliability, uniform brightness, and strong anti-interference ability, which has broad application prospects.

Claims

1. A flexible LED light board circuit, characterized in that, include: Isolated feedback control module (A); LED pixel array module (B); The isolated feedback control module (A) includes two optocouplers (U3, U4) connected in parallel to form a redundant transmission channel; The power control ground (PGND) and logic ground (GND) are physically isolated to form a domain-specific grounding structure; The transient suppression diode (D7) and current limiting resistors (R29, R38) located at the input of the isolated feedback control module (A) form a protection circuit; The compensation networks (C20, C21) set in the isolated feedback control module (A) are respectively arranged on the main control side and the secondary reference side; The LED pixel array module (B) includes multiple intelligent RGB LED beads arranged in a single-line cascade manner; Multiple power injection points are distributed along the LED pixel array module (B).

2. The flexible LED light board circuit according to claim 1, characterized in that, The LED sides of the optocouplers (U3, U4) receive the same signal source in parallel, and the transistor sides work together at the compensation terminal (COMP) node of the error amplifier.

3. The flexible LED light board circuit according to claim 1, characterized in that, In the aforementioned domain grounding structure, the power control ground (PGND) is used for power domain grounding, and the logic ground (GND) is used for signal domain grounding. The two are connected only through isolation devices.

4. The flexible LED light board circuit according to claim 1, characterized in that, The transient suppression diode (D7) and current limiting resistors (R29, R38) in the protection circuit are arranged in front of the feedback signal path to form a protective barrier.

5. The flexible LED light board circuit according to claim 1, characterized in that, The data input terminal (DIN) and data output terminal (DOUT) of the intelligent RGB lamp beads in the LED pixel array module (B) form a series structure, while the power supply terminal (VDD) adopts a parallel structure.

6. The flexible LED light board circuit according to claim 1, characterized in that, The multiple power injection points are distributed such that one injection point is set every predetermined number of LED beads.

7. The flexible LED light board circuit according to claim 1, characterized in that, The isolated feedback control module (A) and the LED pixel array module (B) form a hierarchical control architecture with distributed light-emitting end and centralized control end. The control side accurately locks the bus voltage or brightness through unified isolated feedback.

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