Constant current LED long cascade soft light strip with uniform brightness

Abstract

The utility model discloses a constant current LED long cascade soft lamp strip of even brightness, including circuit board, power supply positive pole main line and power supply negative pole main line and a plurality of with main line link and cascade LED electrical unit. Every LED electrical unit includes constant current drive chip, current -limiting resistance, sampling resistance and LED array. Constant current drive chip is connected power supply positive pole main line through current -limiting resistance, is connected power supply negative pole main line through sampling resistance, and LED array positive pole connects power supply positive pole main line, and the LED pin of negative pole connects constant current drive chip. Circuit board adopts flexible material, and power supply main line is arranged in parallel, and sampling resistance is variable resistance, and the resistance value of current -limiting resistance is determined according to the LED parameter calculation. The utility model solves the problem of traditional constant voltage lamp strip first and last brightness uneven, uneven heating and the complex installation, realizes the effect of long distance cascade time even brightness, stable performance, is applicable to a variety of scenes, and simplifies product management.

Description

Technical Field

[0001] This utility model belongs to the field of flexible LED strip technology, specifically, it relates to a constant current LED long cascade flexible LED strip with uniform brightness. Background Technology

[0002] As a widely used lighting and decorative product, the design and technical implementation of LED flexible light strips have a significant impact on their performance and user experience. Currently, most LED flexible light strips on the market use a constant voltage drive method. While this method performs reasonably well in short-distance applications, as the strip length increases, voltage drop becomes increasingly apparent, leading to noticeable uneven brightness between the beginning and end of the strip. This is particularly evident when the cascaded length reaches 5 or 10 meters, where the brightness difference between the beginning and end is significant, severely impacting visual appeal and product usability. Furthermore, due to the uneven current distribution under constant voltage drive, the portion of the strip closer to the power supply often experiences severe heating due to higher voltage, while the portion farther from the power supply suffers from insufficient voltage and reduced brightness. This uneven heating further accelerates light decay and shortens the product's lifespan.

[0003] On the other hand, to meet the needs of long-distance use, users typically need to configure an additional power supply after every 5 to 10 meters of light strip. This not only increases installation complexity but also significantly increases operating costs, especially in large-scale scenarios where frequent power supply deployment becomes a major challenge. Although a small number of constant-current driven LED light strips exist on the market, these products mostly use a driving scheme composed of two transistors or a design with a single constant-current diode. The former, due to the large number of components, is difficult to adapt to the compact structure requirements of silicone extruded light strips or small-sized neon light strips; the latter lacks a sampling resistor for power regulation, resulting in products with different power requirements having to use different specifications of constant-current diodes, leading to a wide variety and complex management, increasing the difficulty of production and inventory.

[0004] Therefore, developing a constant current LED flexible light strip circuit that can achieve uniform brightness, support long-distance cascading, and has a simple structure has become an urgent problem to be solved in the current technology field. Utility Model Content

[0005] The purpose of this invention is to provide a constant current LED long-cascade flexible light strip with uniform brightness, which mainly solves the problems of uneven brightness at the beginning and end, uneven current distribution, uneven heat generation, and complicated installation caused by constant voltage driving when existing LED flexible light strips are cascaded over long distances.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A constant current LED long cascade flexible light strip with uniform brightness includes a circuit board, a positive power supply main line and a negative power supply main line disposed on the circuit board, and a number of LED electrical units that are connected to and cascaded with the positive power supply main line and the negative power supply main line.

[0008] The LED electrical unit includes a constant current driving chip whose VCC pin is connected to the positive main line of the power supply through a current-limiting resistor and whose CS1 and CS2 pins are connected to the negative main line of the power supply through sampling resistors, and an LED array whose positive terminal is connected to the positive main line of the power supply and whose negative terminal is connected to the LED pins of the constant current driving chip; wherein, the GND pin of the constant current driving chip is also connected to the negative main line of the power supply.

[0009] Furthermore, in this invention, the LED array is composed of several LEDs connected in series or in parallel.

[0010] Furthermore, in this invention, the resistance value of the current-limiting resistor is calculated and determined based on the rated current and operating voltage of each LED.

[0011] Furthermore, in this invention, the sampling resistor is a variable resistor.

[0012] Furthermore, in this invention, the circuit board is a flexible circuit board.

[0013] Furthermore, in this invention, the positive power supply main line and the negative power supply main line are arranged in parallel on the circuit board.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) This utility model supports long-distance cascading of 50 meters and above. Through constant current drive design, it effectively reduces the impact of line voltage drop and ensures uniform brightness at the beginning and end of the light strip.

[0016] (2) This utility model adopts constant current driving technology, the current distribution of the entire light strip is uniform, the power consumption is balanced and the heat generation is low, which significantly extends the service life of the product.

[0017] (3) This utility model, through the combination design of small packaged constant current chip and sampling resistor, can flexibly adjust power and brightness, and is suitable for diverse scenarios such as building lighting, advertising light boxes, and interior decoration.

[0018] (4) This utility model has flexible control and can realize multiple functions such as segmented control and dimming. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the circuit structure of this utility model.

[0020] The names corresponding to the reference numerals in the attached figures are as follows:

[0021] 1-Positive power supply main line; 2-Negative power supply main line; 3-LED electrical unit; 4-Current limiting resistor; 5-Sampling resistor; 6-Constant current driver chip; 7-LED array. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0023] Example

[0024] like Figure 1 As shown, this utility model discloses a constant current LED long-cascade flexible light strip with uniform brightness, including a circuit board and a positive power supply main line 1 and a negative power supply main line 2 disposed on the circuit board. The circuit board also has several cascaded LED electrical units 3, each connected to and cascaded with the positive power supply main line 1 and the negative power supply main line 2. Each LED electrical unit 3 consists of a constant current driver chip 6, a current-limiting resistor 4, a sampling resistor 5, and an LED array 7. These components work together to ensure uniform brightness and stable performance of the LED flexible light strip when cascaded over long distances. In practical applications, the positive power supply main line 1 and the negative power supply main line 2 are arranged parallel on the circuit board. A reasonable width and thickness design reduces line resistance, thereby reducing energy loss during current transmission. The circuit structure of this utility model supports the cascaded connection of multiple constant current units. The VCC and GND of all units are connected through the main power supply line throughout the entire light strip. The current of each constant current unit is independently controlled by the constant current driver chip, without interference between them. Even when the light strip is 50 meters or longer, the brightness of the LEDs at both ends remains highly consistent, greatly improving the product's application range and reliability.

[0025] In the specific implementation, the VCC pin of the constant current driver chip 6 is connected to the positive main power supply line 1 through the current-limiting resistor 4; the CS1 and CS2 pins are connected to the negative main power supply line 2 through the sampling resistor 5; the GND pin is directly connected to the negative main power supply line 2; the positive terminal of the LED array 7 is connected to the positive main power supply line 1, and the negative terminal is connected to the LED pin of the constant current driver chip 6. The constant current driver chip integrates a current detection and regulation circuit, which can automatically adjust the output current according to the voltage change of the external sampling resistor, ensuring a constant current flowing through the LED array. Therefore, even in long-distance cascading, voltage changes caused by line voltage drops will not affect the LED's operating current and brightness.

[0026] In this embodiment, the constant current driver chip also has reserved control ports (such as CS1 and CS2), which can be connected to an external controller or dimming module to realize functions such as segmented switching, brightness adjustment, and dynamic display for each group of LEDs. For example, by controlling the CS1 and CS2 ports with PWM signals, stepless dimming or dynamic flashing effects of the LEDs can be achieved to meet diverse lighting and decoration needs.

[0027] When selecting the constant current driver chip 6, parameters such as its maximum output current, operating voltage range, efficiency, and package type need to be comprehensively considered. In this embodiment, the constant current driver chip 6 adopts the 2N022A high-efficiency constant current chip. The 2N022A is a high-precision constant current LED driver chip with adjustable output current. Only one external resistor is needed to form a complete LED constant current driver circuit, and the output current can be adjusted by adjusting the external resistor. It integrates LED constant current control, analog and digital dimming functions, and PWM signal to adjust the output current; the 2N022A adopts the SOT-363 package type. Its pin definitions are shown in Table 1 below.

[0028] Table 12 Pin Definitions for N022A

[0029] Serial Number Foot position name Function 1 CS1 Current sampling, shorted with CS2 2 SEL1 Chip select signal, shorted to SEL2 3 SEL2 Chip select signal, shorted to SEL1 4 GND Chip ground 5 CS2 Output current setting 6 OUT Output pin

[0030] In this embodiment, the maximum output current of the constant current driver chip 6 must be greater than or equal to the total operating current of the LED array 7 to avoid chip damage due to overload; the operating voltage range must cover the input voltage range of the main positive line 1 of the power supply to ensure that the chip can work normally under different voltage conditions; efficiency determines the overall energy consumption level of the light strip, and a high-efficiency constant current driver chip 6 can effectively reduce the heat generation of the light strip and extend its service life. In practical applications, this invention solves the problem of significant brightness differences between the beginning and end of traditional constant voltage driven light strips when cascaded over long distances through the design of the constant current driver chip 6 and the sampling resistor 5. The constant current driving method makes the current distribution of the entire light strip uniform, avoiding excessive heat generation near the power supply end and extending the service life of the product.

[0031] In this embodiment, the main function of the current-limiting resistor 4 is to limit the maximum current flowing through the LED during initial power-on or in abnormal conditions, preventing damage to the LED due to current surges. The resistance value of the current-limiting resistor is calculated and determined based on the rated current and operating voltage of the LED, ensuring both normal LED brightness and preventing overcurrent.

[0032] In this embodiment, the sampling resistor (such as...) Figure 1RS1 and RS2 in the LED array are used to detect the current flowing through the LED array. The resistance value of the sampling resistor directly determines the operating current of the LED. By changing the sampling resistor with different values, the current of each group of LEDs can be flexibly adjusted to achieve different brightness and power requirements. For example, if brightness needs to be increased, the sampling resistor value can be appropriately decreased; if power consumption needs to be reduced, the sampling resistor value can be appropriately increased.

[0033] In this embodiment, the LED array consists of several LEDs connected in series or parallel. Taking 8 LEDs per group as an example, the positive terminal of each LED is connected to the main power supply VCC, and the negative terminal is connected to the LED terminal of the constant current driver chip. By reasonably designing the number of series and parallel connections, the operating voltage and brightness of each group of LEDs can be adjusted according to actual needs. Each group of LEDs adopts a modular design, which facilitates production and maintenance.

[0034] This invention utilizes flexible circuit board material to fabricate the circuit board, giving the LED strip excellent flexibility and adaptability, facilitating bending and installation, and making it suitable for various complex operating environments. The selection of the flexible circuit board material must consider its conductivity, heat resistance, and mechanical strength to ensure that the circuit board will not break or experience poor contact during repeated bending. Furthermore, the design of the flexible circuit board requires optimization of the layout of the positive power supply line 1 and the negative power supply line 2 to reduce the impact of voltage drop on brightness. The width and thickness of the positive power supply line 1 and the negative power supply line 2 need to be calculated based on the maximum operating current of the LED strip and the allowable voltage drop to ensure uniform and stable current distribution. The spacing between the positive power supply line 1 and the negative power supply line 2 has also been optimized to avoid signal distortion caused by electromagnetic interference.

[0035] In specific embodiments, due to the use of small-packaged constant current chips and sampling resistors, this circuit is suitable for space-constrained applications such as small-sized silicone neon light strips. By adjusting the number of LEDs, the value of the sampling resistor, and the model of the constant current chip, it can flexibly adapt to light strip products of different lengths, power, and brightness to meet diverse market demands. For example, in shopping malls, using the LED flexible light strip of this invention can significantly reduce the number of power supplies required, lower wiring complexity, and improve construction efficiency. Simultaneously, since the light strip length can reach 20 meters or even longer, shopping malls can flexibly arrange the light strip positions according to actual needs without frequent power supply replacements. In large exhibition halls, the LED flexible light strip of this invention can adapt to the lighting needs of different areas by adjusting the resistance value of the sampling resistor 5. For example, the brightness can be increased in the exhibit display area and decreased in the rest area, thereby creating different atmospheres. In indoor and outdoor decoration, the LED flexible light strip of this invention, due to its flexible circuit board, has excellent bending performance and can be easily installed on surfaces of various complex shapes, such as curved walls and cylinders, thereby meeting diverse decorative needs.

[0036] In summary, this invention overcomes many shortcomings of existing technologies through reasonable circuit design and component selection, providing a constant current LED flexible light strip long cascade circuit with uniform brightness, stable performance, and convenient installation. In practical applications, the LED flexible light strip of this invention can not only achieve long-distance cascading and maintain uniform brightness, but also adapt to different lighting scenarios by adjusting the resistance value of the sampling resistor 5, significantly improving the product's adaptability and flexibility. The use of a flexible circuit board and a high-efficiency constant current driver chip 6 gives the light strip excellent flexibility and heat dissipation performance, making it suitable for various complex operating environments. Through the technical solution of this invention, the performance and user experience of LED flexible light strips can be significantly improved, providing strong support for technological advancements in related fields.

[0037] The above embodiments are merely one of the preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications or refinements made to the main design concept and spirit of this utility model that are not of substantial significance, but solve the same technical problem as this utility model, should be included within the scope of protection of this utility model.

Claims

1. A constant current LED long cascade soft light strip with uniform brightness, comprising a circuit board, a power supply positive main line (1) and a power supply negative main line (2) arranged on the circuit board, characterized in that, It also includes several LED electrical units (3) that are connected and cascaded to the positive power supply main line (1) and the negative power supply main line (2); The LED electrical unit (3) includes a constant current driving chip (6) whose VCC pin is connected to the positive main line (1) of the power supply through a current limiting resistor (4) and whose CS1 and CS2 pins are connected to the negative main line (2) of the power supply through a sampling resistor (5), and an LED array (7) whose positive terminal is connected to the positive main line (1) of the power supply and whose negative terminal is connected to the LED pin of the constant current driving chip (6); wherein, the GND pin of the constant current driving chip (6) is also connected to the negative main line (2).

2. The long cascade constant current LED soft strip light with uniform brightness according to claim 1, characterized in that, The LED array (7) is composed of several LEDs connected in series or in parallel.

3. The long constant current LED soft strip light with uniform brightness according to claim 2, characterized in that, The resistance value of the current-limiting resistor (4) is calculated and determined based on the rated current and operating voltage of each LED.

4. The long constant current LED soft strip light with uniform brightness according to claim 3, characterized in that, The sampling resistor (5) is a variable resistor.

5. A constant current LED long cascade soft strip light with uniform brightness according to claim 4, characterized in that, The circuit board is a flexible circuit board.

6. A constant current LED long cascade soft strip light with uniform brightness according to claim 5, characterized in that, The positive power supply main line (1) and the negative power supply main line (2) are arranged in parallel on the circuit board.

Images