A multi-LED lamp bead control system

Abstract

The utility model discloses a kind of multi LED lamp bead control systems, including DC / DC converter, micro control unit, one or more PCB substrates and switching unit, multiple LED modules are equipped on PCB substrate, at least two groups of LED units are equipped on each LED module, each group of the LED unit includes multiple LED lamp beads, between each group the LED unit and in each group the LED unit the LED lamp bead is formed into lattice circuit by series-parallel connection mode, the DC / DC converter, the micro control unit and each the LED module are connected with the switching unit. The utility model designs the LED lamp bead of each PCB substrate and forms lattice circuit, can realize the lamp bead brightness control of multiple LED lamp beads by a DC / DC converter and a switching unit, can reduce circuit design cost, can be widely applied in light control technical field.

Description

Technical Field

[0001] This utility model relates to the field of lighting control technology, and in particular to a multi-LED lamp bead control system. Background Technology

[0002] With the booming development of new energy vehicles in China, there is a growing demand for innovative and diverse headlight designs. The number of LEDs used is also increasing. LED chips primarily rely on driver chips to achieve stable current output. Due to limitations in component specifications, each buck-boost DC / DC converter typically drives only 12 LED chips. For example, if each LED chip has a VF of 3V, the buck-boost DC / DC converter outputs 36V, and the output filter capacitor has a withstand voltage of 50V. Increasing the number of LED chips requires more buck-boost DC / DC converters, leading to higher costs. Utility Model Content

[0003] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a control system and control method for multiple LED beads, which can reduce circuit design costs.

[0004] The technical solution adopted by this utility model is:

[0005] A multi-LED control system includes a DC / DC converter, a microcontroller unit, one or more PCB substrates, and a switching unit. The PCB substrate has multiple LED modules, and each LED module has at least two sets of LED units. Each set of LED units includes multiple LEDs. The LED units in each set and the LEDs in each set of LED units are connected in series and parallel to form a grid circuit. The DC / DC converter, the microcontroller unit, and each LED module are all connected to the switching unit.

[0006] Furthermore, the switching unit includes multiple FET channels, the number of which is equal to the number of LED modules, and each FET channel is connected to an LED module in a one-to-one correspondence.

[0007] Furthermore, each of the FET channels is a field-effect transistor, the gate of each field-effect transistor is connected to one end of all the LED units of the corresponding LED module, and the drain of each field-effect transistor is connected to the other end of all the LED units of the corresponding LED module.

[0008] Furthermore, each LED unit also includes multiple current-sharing resistors, the number of which is the same as the number of LED beads, and each current-sharing resistor is connected in series with each LED bead.

[0009] Furthermore, there are at least two PCB substrates, and each PCB substrate also includes a BIN resistor. One end of the BIN resistor is connected to the microcontroller unit, and the other end of the BIN resistor is grounded.

[0010] Furthermore, the LED brightness BIN levels of at least two of the PCB substrates are different.

[0011] Furthermore, the resistance value of the BIN resistor on each of the PCB substrates corresponds to the brightness BIN level of the LED on the PCB substrate.

[0012] Furthermore, the PCB substrate is at least one, and the light-emitting intensities of the lamp beads in at least two of the LED modules are different.

[0013] Furthermore, the PCB substrate is at least one, and the LED beads of at least two of the LED modules are of different colors.

[0014] Furthermore, the PCB substrate is at least one, and the number of LED beads in at least two of the LED modules is different.

[0015] The beneficial effects of this utility model are as follows: This utility model provides a multi-LED lamp bead control system, including a DC / DC converter, a microcontroller unit, one or more PCB substrates, and a switching unit. Multiple LED modules are mounted on the PCB substrate, and each LED module has at least two sets of LED units. Each set of LED units includes multiple LED beads, and the LED beads within each set of LED units are connected in series and parallel to form a grid circuit. This utility model's design, where the LED beads on each PCB substrate form a grid circuit, allows for the control of the brightness of multiple LED beads using only a DC / DC converter and a switching unit, thus reducing circuit design costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a multi-LED lamp bead control system provided in one embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the current when an LED bead is open-circuited, provided in one embodiment of the present invention.

[0018] Figure 3 This is a schematic diagram of the structure of a multi-LED control system with different LED brightness BIN levels provided in one embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of the output current of a PCB substrate provided in one embodiment of the present invention;

[0020] Figure 5 This is a structural block diagram of a control system for multiple LED beads with different luminous intensities provided in one embodiment of the present invention;

[0021] Figure 6 This is a structural block diagram of a multi-LED bead control system with different bead colors provided in one embodiment of the present invention;

[0022] Figure 7 This is a structural block diagram of a multi-LED control system with different numbers of LED beads provided in one embodiment of the present invention. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0024] Before providing a detailed description of the embodiments of this utility model, some of the nouns and terms involved in the embodiments of this utility model will be explained first. The nouns and terms involved in the embodiments of this utility model are subject to the following interpretations.

[0025] Buck-boost DC / DC converter: A power management chip that can simultaneously boost and buck voltage and output a stable current;

[0026] Switching unit: A chip that integrates a bypass switch for controlling current switching;

[0027] Time-sharing multiplexing: The same step-up / step-down DC / DC converter outputs a constant current, and the switching unit divides the lighting time of the LED beads according to the demand, so as to achieve the same output current to meet the LED beads with different current requirements.

[0028] LED brightness BIN rating: The brightness intensity produced by an LED when it emits light. LEDs of the same model have different brightness ratings, and the brightness intensity of different ratings is not consistent when given the same current.

[0029] The N-1 light distribution regulation states that for a single lamp equipped with more than one light source, if any one of its light sources fails, the remaining light sources (i.e., N-1 light sources) can still meet the light distribution performance requirements.

[0030] Lattice circuit: A circuit in which devices are connected in series and parallel, resembling a grid.

[0031] PCB ASSY A: PCB substrate A, the finished product after SMT components are installed or DIP components are inserted into the PCB blank board;

[0032] DUTY: Duty cycle, the proportion of the on-time relative to the total time within a pulse cycle;

[0033] BIN resistor: A resistor that is one-to-one matched with the brightness BIN level of the LED chip, used by the microcontroller unit to confirm the brightness level of the LED chip.

[0034] With the booming development of new energy vehicles in China, there is a growing demand for innovative and diverse headlight designs. The number of LEDs used is also increasing. LED chips primarily rely on driver chips to achieve stable current output. Due to limitations in component specifications, each buck-boost DC / DC converter typically drives only 12 LED chips. For example, if each LED chip has a VF of 3V, the buck-boost DC / DC converter outputs 36V, and the output filter capacitor has a withstand voltage of 50V. Increasing the number of LED chips requires more buck-boost DC / DC converters, leading to higher costs.

[0035] Therefore, this utility model proposes a multi-LED lamp bead control system, including a DC / DC converter, a microcontroller unit, one or more PCB substrates, and a switching unit. Multiple LED modules are mounted on the PCB substrate, and each LED module has at least two sets of LED units. Each set of LED units includes multiple LED lamp beads, and the LED units in each set are connected in series and parallel to form a grid circuit. This utility model designs the LED lamp beads on each PCB substrate to form a grid circuit, allowing the brightness control of multiple LED lamp beads to be achieved with a single DC / DC converter and a switching unit, thus reducing circuit design costs.

[0036] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of a multi-LED lamp bead control system provided in one embodiment of the present invention. The present invention proposes a multi-LED lamp bead control system, including a DC / DC converter, a microcontroller unit, one or more PCB substrates, and a switching unit. The PCB substrate is provided with multiple LED modules, and each LED module is provided with at least two sets of LED units. Each set of LED units includes multiple LED lamp beads. The LED units in each set of LED units and the LED lamp beads in each set of LED units are connected in series and parallel to form a grid circuit. The DC / DC converter, the microcontroller unit, and each LED module are all connected to the switching unit.

[0037] Reference Figure 1 As an optional implementation, the switching unit includes multiple FET channels, the number of which is equal to the number of LED modules, and each FET channel is connected to an LED module in a one-to-one correspondence.

[0038] Reference Figure 1As an optional implementation, the FET channels are all field-effect transistors, the gate of each field-effect transistor is connected to one end of all LED units of the corresponding LED module, and the drain of each field-effect transistor is connected to the other end of all LED units of the corresponding LED module.

[0039] Specifically, the DC / DC converter in this embodiment of the present invention is a step-up / step-down type. This step-up / step-down type DC / DC converter is used to provide a stable current output for LED beads. It can realize the step-up or step-down function through the power conversion circuit according to the input voltage and the required output current, so as to ensure that the output current of the LED at the back end is constant.

[0040] The switching unit contains multiple FET channels to control the duty cycle (DUTY) of each FET channel, thereby controlling the on / off state of each LED module on the PCB substrate. In this embodiment of the invention, one LED module is connected to an independent FET channel to independently control the current of each LED module, thereby improving the flexibility and controllability of the system.

[0041] The microcontroller unit (MCU) is connected to the switching unit via serial communication (UART) to control the switching unit to open or close specific FET channels, thereby controlling the on / off state of the LED module;

[0042] like Figure 1 The red box in the image represents an LED module. The LED units on this module are composed of LED beads connected in series and parallel to form a grid circuit. Each grid circuit consists of two or more LED units connected in parallel. The parallel connection of LED beads ensures that the voltage of each LED unit does not exceed the limit of the FET channel of the switching unit, allowing each FET channel of the switching unit to control more LED beads.

[0043] As an optional implementation, each LED unit also includes multiple current-sharing resistors, the number of which is the same as the number of LED chips, and each current-sharing resistor is connected in series with each LED chip.

[0044] It should be noted that since the LED loads are all grid circuits with 2 or more parallel circuits, the design ensures that even if any one LED is open-circuited, the remaining LEDs can still light up normally, thus meeting the N-1 light distribution regulations. For example... Figure 2 The diagram shows the current when the LED beads are open-circuited. Each LED bead is connected in series with a current-sharing resistor. When LED6 is open-circuited, the current can flow from LED1 to the LED1 above as indicated by the green arrow, ensuring that the remaining LED beads light up normally and that the remaining LED beads meet the light distribution requirements of the luminaire.

[0045] The above describes part of the structure of the multi-LED lamp bead control system of this utility model. The following describes the working process of the multi-LED lamp bead control system with reference to examples.

[0046] In some alternative embodiments, such as Figure 3 The diagram shows a schematic of a multi-LED control system with different brightness BIN levels according to an embodiment of this invention. The system has 160 LEDs, which are divided into four PCB substrates according to the current required by the LEDs, with 40 LEDs on each PCB substrate. A DC / DC converter outputs a stable current to the LEDs. The microcontroller unit communicates serially with the switching unit to control the opening and closing of the FET channels within the switching unit, thereby adjusting the on-time of the LEDs on each PCB substrate. This achieves time-division multiplexing control of multiple LEDs by a single DC / DC converter and switching unit. Figure 4 The diagram shows the output current of the PCB substrate. Each PCB substrate is lit according to the current magnitude. The duty cycle of PCB-ASSY-A (PCB substrate A) is 25%, the duty cycle of PCB-ASSY-B (PCB substrate B) is 23%, the duty cycle of PCB-ASSY-C (PCB substrate C) is 22%, and the duty cycle of PCB-ASSY-D (PCB substrate D) is 20%.

[0047] Reference Figure 3 As an optional implementation, there are at least two PCB substrates, each of which also includes a BIN resistor. One end of the BIN resistor is connected to the microcontroller unit, and the other end of the BIN resistor is connected to the switching unit.

[0048] As a further optional implementation, the LED brightness BIN levels of at least two PCB substrates are different.

[0049] As a further optional implementation, the resistance value of the BIN resistor on each PCB substrate corresponds to the brightness BIN level of the LED on that PCB substrate.

[0050] Specifically, when LEDs with different brightness BIN levels are mounted on different PCB substrates, the output load of this system is ≥2 PCB substrates, and the LEDs on at least two PCB substrates have different brightness BIN levels. By setting BIN resistors with resistance values ​​corresponding to the brightness BIN levels of the LEDs on the PCB substrates, the resistance value is output to the microcontroller unit. Finally, the duty cycle of the corresponding FET channel is adjusted by the microcontroller unit and the switching unit to ensure the uniformity of brightness on each PCB substrate.

[0051] For example, four PCB substrates are configured (PCB substrate A, PCB substrate B, PCB substrate C, and PCB substrate D). Each PCB substrate is equipped with LEDs of the same model, but the brightness BIN levels of the LEDs are different. Corresponding brightness BIN resistors are attached to each PCB substrate according to the brightness BIN level of the LEDs. For example, the LEDs on PCB-ASSY-A (PCB substrate A) have a brightness BIN level of 1, and the resistance value of its BIN resistor is 30kΩ; the LEDs on PCB-ASSY-B (PCB substrate B) have a brightness BIN level of 2, and the resistance value of its BIN resistor is 9kΩ. Through the integrated design of the microcontroller unit and the switching unit, the duty cycle of the corresponding FET channel can be adjusted to the corresponding value based on the input resistance value, ensuring uniform brightness even when LEDs of the same model but different brightness BIN levels are mounted on the PCB substrate.

[0052] As a further optional implementation, the PCB substrate is at least one, and the light-emitting intensities of the lamp beads in at least two LED modules are different.

[0053] Specifically, such as Figure 5 The diagram shows a structural block diagram of a multi-LED control system with different luminous intensities according to an embodiment of this invention. When the output load is ≥1 PCB substrate, and each PCB substrate has ≥2 groups of LED modules, LEDs with different luminous intensities are mounted on each PCB substrate. For example, high-power LEDs (high brightness) are used for high and low beams, while low-power LEDs (low brightness) are used for position lights. High-brightness LEDs require more current, so the duty cycle of the LED module is adjusted to 40% through the microcontroller unit and switching unit; low-brightness LEDs require less current, so the duty cycle of the LED module is adjusted to 10% through the microcontroller unit and switching unit, thereby achieving arbitrary brightness adjustment.

[0054] As a further optional implementation, the PCB substrate is at least one, and the LEDs of at least two LED modules have different colors.

[0055] Specifically, such as Figure 6The diagram shown is a structural block diagram of a multi-LED control system with different LED colors provided in one embodiment of this utility model. When the output load is ≥1 PCB substrate and each PCB substrate has ≥2 groups of LED modules, LEDs of different colors are mounted on each PCB substrate. Different functions require different currents, such as daytime running lights (DRL), clearance lights (CLL), and turn signals. The duty cycle of the daytime running lights is adjusted to 25%, the duty cycle of the clearance lights is adjusted to 5%, and the duty cycle of the turn signals is adjusted to 25% through the microcontroller unit and the switching unit, thereby realizing the adjustment of the brightness of different LED colors.

[0056] As a further optional implementation, the PCB substrate is at least one, and the number of LED beads in at least two LED modules is different.

[0057] Specifically, such as Figure 7 The diagram shown is a structural block diagram of a multi-LED control system with different numbers of LED beads provided in an embodiment of the present invention. When the output load is ≥1 PCB substrate and each PCB substrate has ≥2 groups of LED modules, the number of parallel LED unit groups (≥2) on each PCB substrate and the number of LED beads in each group of LED units are adjustable. The duty cycle of the LED units on each PCB substrate is set by the microcontroller unit and the switching unit to achieve arbitrary brightness adjustment for different numbers of LED beads.

[0058] The structure and working principle of the multi-LED bead control system of this utility model have been described above. It can be understood that, compared with the traditional LED bead control system, this utility model has the following advantages:

[0059] 1. Design the LED beads on each PCB substrate to form a grid circuit. When any one LED bead is open-circuited, the remaining LED beads can still light up normally, which can meet the N-1 light distribution regulations.

[0060] 2. The brightness control of multiple LED beads can be achieved by using a DC / DC converter and a switching unit, which can reduce the number of DC / DC converters and switching units and achieve the control of multiple LED beads with very low driving cost.

[0061] Third, it can adapt to LED beads with different brightness BIN levels, ensuring uniform brightness, and can flexibly control multiple LED beads to achieve arbitrary brightness adjustment of LED beads with different luminous intensities, or arbitrary brightness adjustment of different LED bead colors, or arbitrary brightness adjustment of different numbers of LED beads.

[0062] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0063] In this utility model, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0064] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0065] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A control system for multiple LED beads, characterized in that, The device includes a DC / DC converter, a microcontroller unit, one or more PCB substrates, and a switching unit. The PCB substrate has multiple LED modules, and each LED module has at least two sets of LED units. Each set of LED units includes multiple LED beads. The LED units in each set and the LED beads in each set of LED units form a grid circuit through series and parallel connections. The DC / DC converter, the microcontroller unit, and each LED module are all connected to the switching unit.

2. The multi-LED lamp bead control system according to claim 1, characterized in that, The switching unit includes multiple FET channels, the number of which is equal to the number of LED modules, and each FET channel is connected to an LED module in a one-to-one correspondence.

3. The multi-LED lamp bead control system according to claim 2, characterized in that, The FET channels are all field-effect transistors, and the gate of each field-effect transistor is connected to one end of all the LED units of the corresponding LED module, and the drain of each field-effect transistor is connected to the other end of all the LED units of the corresponding LED module.

4. The multi-LED lamp bead control system according to claim 1, characterized in that: Each LED unit also includes multiple current-sharing resistors, the number of which is the same as the number of LED beads, and each current-sharing resistor is connected in series with each LED bead.

5. A multi-LED lamp bead control system according to claim 1, characterized in that, The PCB substrate comprises at least two pieces, and each PCB substrate further includes a BIN resistor. One end of the BIN resistor is connected to the microcontroller unit, and the other end of the BIN resistor is grounded.

6. A multi-LED lamp bead control system according to claim 5, characterized in that, At least two of the PCB substrates have different LED brightness BIN levels.

7. A multi-LED lamp bead control system according to claim 6, characterized in that: The resistance value of the BIN resistor on each of the PCB substrates corresponds to the brightness BIN level of the LED on the PCB substrate.

8. A multi-LED lamp bead control system according to claim 1, characterized in that: The PCB substrate is at least one, and the light-emitting intensity of the lamp beads in at least two of the LED modules is different.

9. A multi-LED lamp bead control system according to claim 1, characterized in that: The PCB substrate is at least one, and the LED beads of at least two of the LED modules are of different colors.

10. A multi-LED lamp bead control system according to claim 1, characterized in that: The PCB substrate is at least one, and the number of LED beads in at least two of the LED modules is different.

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