LED open-circuit protection circuit, lighting components and vehicles

Abstract

This application discloses an LED open-circuit protection circuit, a lighting assembly, and a vehicle. The LED open-circuit protection circuit includes: at least one LED driver module, each connected to a set of LED strings for driving the LED strings; at least one LED open-circuit detection module, each connected to a set of LED strings for generating a corresponding open-circuit detection signal; a fault feedback module connected to the LED open-circuit detection module for outputting a fault feedback signal when the open-circuit detection signal indicates that the LED strings are open-circuited; and an open-circuit protection module connected to both the fault feedback module and each LED driver module, which disconnects from the LED driver module and stops supplying power to the LED driver module upon receiving the fault feedback signal. This approach reduces the hardware cost of the LED open-circuit protection circuit.

Description

Technical Field

[0001] This application relates to the field of open circuit detection technology, and in particular to LED open circuit protection circuits, lighting components, and vehicles. Background Technology

[0002] As the automotive industry moves towards intelligence, energy efficiency, and personalization, LED (Light Emitting Diode) technology has become a core solution for automotive lighting and signaling systems due to its advantages such as high efficiency, long lifespan, fast response, and design flexibility. Traditional halogen and xenon lamps suffer from high energy consumption, short lifespan, and slow response speed. LED technology, through its semiconductor light-emitting principle, significantly improves energy efficiency (reaching over 80% luminous efficacy) and achieves millisecond-level response, meeting the complex demands of modern automobiles for safety (such as adaptive high beams, ADB), energy saving (reducing the vehicle's electrical load), and styling design (such as continuous taillights and dynamic welcome lighting effects). With the development of automotive intelligence and connectivity, the complexity of automotive lighting systems (LED / laser / matrix) has significantly increased, posing new technical challenges to their fault diagnosis and feedback mechanisms.

[0003] In response to the development of automotive intelligence and connectivity, various car manufacturers use integrated LED driver ICs (Integrated Circuits) for fault feedback of headlights. These are relatively integrated and can be applied directly. However, an MCU (Microcontroller Unit) is needed to determine whether the LED is faulty. After a fault occurs, the MCU makes a strategy to control the LED to turn on or off. However, the hardware cost of using an MCU is relatively high. Utility Model Content

[0004] This application provides an LED open-circuit protection circuit, a lighting assembly, and a vehicle, which can reduce the hardware cost of the LED open-circuit protection circuit.

[0005] To solve the above-mentioned technical problems, this application adopts the following technical solution: An LED open-circuit protection circuit is provided, comprising: at least one LED driver module, each LED driver module connected to a group of LED strings for driving the LED strings to operate; at least one LED open-circuit detection module, each LED open-circuit detection module connected to a group of LED strings for generating a corresponding open-circuit detection signal; a fault feedback module connected to the LED open-circuit detection module for outputting a fault feedback signal when the open-circuit detection signal indicates that the LED string is open-circuited; and an open-circuit protection module connected to both the fault feedback module and each LED driver module, which disconnects from the LED driver module and stops supplying power to the LED driver module upon receiving the fault feedback signal.

[0006] Each LED driver module includes: a first driver unit, the first end of which is connected to an open-circuit protection module, and the second end of which is connected to the output end of the LED string; and a second driver unit, the first end of which is connected to the third end of the first driver unit, the second end of which is connected to the fourth end of the first driver unit, and the third and fourth ends of the second driver unit are grounded.

[0007] The first driving unit includes: a first adjustment unit, the input terminal of which is connected to the open-circuit protection module; a first transistor, the control terminal of which is connected to the output terminal of the first adjustment unit, and the first terminal of which is connected to the negative terminal of the LED string; the second driving unit includes: a second transistor, the first terminal of which is connected to the adjustment node of the first adjustment unit, and the second terminal of which is grounded; a second adjustment unit, the adjustment node of which is connected to the second terminal of the first transistor; the first terminal of which is connected to the control terminal of the second transistor, and the second terminal of which is grounded.

[0008] Each LED open-circuit detection module includes: a first resistor, the first end of which is connected to the output terminal of the LED string; a second resistor, the first end of which is connected to the input terminal of the LED string; a third transistor, the control terminal of which is connected to the second terminal of the first resistor, the first terminal of which is connected to the second terminal of the second resistor, and the second terminal of which is grounded; and a first diode, the anode of which is connected to the first terminal of the third transistor, and the cathode of which is connected to the fault feedback module.

[0009] The fault feedback module includes: a third driving unit, the first end of which serves as the input terminal of the fault feedback module and is connected to each LED open-circuit detection module; the second end of which serves as the output terminal of the fault feedback module and is connected to the open-circuit protection module; and the second end of which is connected to the input terminal of the LED string through a third resistor; and a fourth driving unit, the first end of which is connected to the first end of the third driving unit; the second end of which is connected to the third end of the third driving unit; and the third and fourth ends of the fourth driving unit are grounded.

[0010] The third driving unit includes: a fourth resistor, the first end of which is connected to each LED open-circuit detection module; a fourth transistor, the control terminal of which is connected to the second end of the fourth resistor, and the first end of which is connected to the open-circuit protection module; the fourth driving unit includes: a fifth transistor, the first end of which is connected to the first end of the fourth resistor, and the second end of which is grounded; a fifth resistor, the first end of which is connected to the control terminal of the fifth transistor, and the second end of which is connected to the second end of the fourth transistor; and a sixth resistor, the first end of which is connected to the second end of the fifth resistor, and the second end of which is grounded.

[0011] The open-circuit protection module includes: a first control unit, the first end of which is connected to a power supply, and the second end of which is connected to each LED driver module; and a second control unit, the control end of which is connected to a fault feedback module, the first end of which is connected to the control end of the first control unit, and the second end of which is grounded. When the second control unit receives a fault feedback signal, it controls the first control unit to disconnect from the LED driver module and stop supplying power to the LED driver module.

[0012] The first control unit includes: a sixth transistor, the first end of which is connected to a power supply, and the second end of which is connected to each LED driver module; a first voltage divider unit, the first end of which is connected to a power supply, and the second end of which is connected to the first end of the second control unit, with the voltage divider node of the first voltage divider unit connected to the control terminal of the sixth transistor; and a Zener diode, the negative terminal of which is connected to a power supply, and the positive terminal of which is connected to the voltage divider node of the first voltage divider unit.

[0013] The second control unit includes: a second diode, the positive terminal of which is connected to the fault feedback module; a seventh resistor, the first end of which is connected to the negative terminal of the second diode; and a seventh transistor, the control terminal of which is connected to the second end of the seventh resistor, the first end of which is connected to the control terminal of the first control unit, and the second end of which is grounded.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a lighting component, which includes at least one set of LED strings and an LED open-circuit protection circuit as provided in the above technical solution.

[0015] To solve the above-mentioned technical problems, another technical solution adopted in this application is to provide a vehicle that includes an LED open-circuit protection circuit as provided by the above technical solution, or includes a lighting assembly as provided by the above technical solution.

[0016] The LED open-circuit protection circuit, lighting assembly, and vehicle provided in this application utilize passive devices to construct at least one LED driver module, at least one LED open-circuit detection module, fault feedback module, and open-circuit protection module in the LED open-circuit protection circuit. It does not require chips or MCUs and can automatically shut down all LED driver modules and protect the LED strings by using the control logic of at least one LED open-circuit detection module, fault feedback module, and open-circuit protection module to turn off the power when any group of LED strings is detected to be open-circuited, without the need for the MCU to make a strategy. This reduces the hardware cost of the LED open-circuit protection circuit. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of an embodiment of the LED open-circuit protection circuit provided in this application; Figure 2 yes Figure 1 A schematic diagram of the structure of an embodiment of the LED driver module; Figure 3 yes Figure 1 A schematic diagram of the structure of an embodiment of the LED open circuit detection module; Figure 4 yes Figure 1 A schematic diagram of the structure of an embodiment of the fault feedback module; Figure 5 yes Figure 1 A schematic diagram of the structure of an embodiment of the open-circuit protection module; Figure 6 This is a schematic diagram of another embodiment of the LED open-circuit protection circuit provided in this application; Figure 7 This is a schematic diagram of the structure of an embodiment of the lighting component provided in this application; Figure 8 This is a schematic diagram of the structure of an embodiment of the vehicle provided in this application; Figure 9 This is a structural schematic diagram of an embodiment of the vehicle provided in this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0019] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0020] As the automotive industry moves towards intelligence, energy efficiency, and personalization, LED (Light Emitting Diode) technology has become a core solution for automotive lighting and signaling systems due to its advantages such as high efficiency, long lifespan, fast response, and design flexibility. Traditional halogen and xenon lamps suffer from high energy consumption, short lifespan, and slow response speed. LED technology, through its semiconductor light-emitting principle, significantly improves energy efficiency (reaching over 80% luminous efficacy) and achieves millisecond-level response, meeting the complex demands of modern automobiles for safety (such as adaptive high beams, ADB), energy saving (reducing the vehicle's electrical load), and styling design (such as continuous taillights and dynamic welcome lighting effects). With the development of automotive intelligence and connectivity, the complexity of automotive lighting systems (LED / laser / matrix) has significantly increased, posing new technical challenges to their fault diagnosis and feedback mechanisms.

[0021] In response to the development of automotive intelligence and connectivity, various car manufacturers use integrated LED driver ICs (Integrated Circuits) for fault feedback of headlights. These are relatively integrated and can be applied directly. However, an MCU (Microcontroller Unit) is needed to determine whether the LED is faulty. After a fault occurs, the MCU makes a strategy to control the LED to turn on or off. However, the hardware cost of using an MCU is relatively high.

[0022] Based on this, this application proposes to construct an LED open-circuit protection circuit using passive devices, comprising at least one LED driver module, at least one LED open-circuit detection module, a fault feedback module, and an open-circuit protection module. This eliminates the need for chips and MCUs, enabling the LED open-circuit protection circuit to automatically shut down all LED driver modules and protect the LED strings by utilizing the control logic of at least one LED open-circuit detection module, fault feedback module, and open-circuit protection module when an open circuit is detected in any group of LED strings. This reduces the hardware cost of the LED open-circuit protection circuit. See any of the following embodiments for details.

[0023] See Figure 1 , Figure 1This is a schematic diagram of an embodiment of the LED open-circuit protection circuit provided in this application. The LED open-circuit protection circuit 100 includes: at least one LED driving module 10, at least one LED open-circuit detection module 20, a fault feedback module 30, and an open-circuit protection module 40.

[0024] Each LED driver module 10 is connected to a set of LED light strings (not shown) to drive the LED light strings to work.

[0025] In some embodiments, the LED driver module 10 can be connected to the output terminal of the LED string, and the input terminal of the LED string is used to connect to a power supply. Driven by the LED driver module 10, the on / off state of the LED string can be controlled. The number of LED driver modules 10 is determined by the number of LED strings. For example, if there are two sets of LED strings, two LED driver modules 10 can be set. That is, the LED driver module 10 is connected to each LED string in a one-to-one correspondence.

[0026] Each LED open-circuit detection module 20 is connected to a set of LED strings to generate a corresponding open-circuit detection signal.

[0027] In some embodiments, the LED open-circuit detection module 20 can be connected to the output terminal of the LED string, and the input terminal of the LED string is used to connect to a power supply. During operation, the open-circuit detection signal can include a first open-circuit detection signal and a second open-circuit detection signal. The first open-circuit detection signal indicates that the LED string is not open-circuited, and the second open-circuit detection signal indicates that the LED string is open-circuited. In some embodiments, the first open-circuit detection signal can be a low-level signal, and the second open-circuit detection signal can be a high-level signal.

[0028] The number of LED open-circuit detection modules 20 is determined by the number of LED strings. For example, if there are two sets of LED strings, then two LED open-circuit detection modules 20 can be set. That is, the LED open-circuit detection modules 20 are connected to the LED strings one-to-one.

[0029] The fault feedback module 30 is connected to the LED open-circuit detection module 20 and is used to output a fault feedback signal when the open-circuit detection signal indicates that the LED string is open. Similarly, different level signals can be used to indicate whether a fault has occurred. When the open-circuit detection signal indicates that the LED string is open, a low-level signal is output, which is used to indicate a fault feedback signal. When the open-circuit detection signal indicates that the LED string is not open, a high-level signal is output, which is used to indicate that the LED string is normal.

[0030] The open-circuit protection module 40 is connected to the fault feedback module 30 and each LED driver module 10 respectively. When it receives a fault feedback signal, it disconnects from the LED driver module 10 and stops supplying power to the LED driver module 10.

[0031] In some embodiments, the open-circuit protection module 40 controls the LED driver module 10. When the LED string is normal, the open-circuit protection module 40 does not activate the protection function and supplies power to the LED driver module 10. Upon receiving a fault feedback signal, it disconnects from the LED driver module 10 and stops supplying power to the LED driver module 10.

[0032] In this embodiment, at least one LED driver module 10, at least one LED open-circuit detection module 20, a fault feedback module 30, and an open-circuit protection module 40 in the LED open-circuit protection circuit 100 are constructed using passive devices. This eliminates the need for chips and MCUs, enabling the LED open-circuit protection circuit to automatically shut down the power supply to all LED driver modules and protect the LED strings when any group of LED strings is detected to be open-circuited, without requiring any MCU intervention. This reduces the hardware cost of the LED open-circuit protection circuit. Passive devices, as opposed to active devices, refer to circuit elements that do not affect the basic characteristics of the signal but merely allow the signal to pass without modification. Common examples include resistors, capacitors, inductors, ceramic oscillators, crystal oscillators, and transformers. In some embodiments, passive devices may also be referred to as passive components.

[0033] See Figure 2 The following describes any of the LED driver modules 10 described above: The LED driver module 10 includes: a first driver unit 11 and a second driver unit 12.

[0034] The first end of the first driving unit 11 is connected to the open-circuit protection module 40, for example, to receive the signal Vin_OPEL provided by the open-circuit protection module 40. The second end of the first driving unit 11 is connected to the output terminal of the LED string. In some embodiments, the first driving unit 11 may be composed of several transistors or MOSFETs.

[0035] The first end of the second driving unit 12 is connected to the third end of the first driving unit 11, and the second end of the second driving unit 12 is connected to the fourth end of the first driving unit 11. The third and fourth ends of the second driving unit 12 are grounded. In some embodiments, the second driving unit 12 may be composed of a plurality of transistors or MOSFETs.

[0036] The first driving unit 11 and the second driving unit 12 cooperate with each other to turn the LED light string on and off.

[0037] Furthermore, the first driving unit 11 includes: a first adjustment unit 111 and a first transistor Q2.

[0038] The input terminal of the first adjustment unit 111 is connected to the aforementioned open-circuit protection module 40. In some embodiments, the first adjustment unit 111 may be composed of several resistors connected together, such as two resistors, three resistors, etc. Figure 2 The first adjustment unit 111 includes resistor R1 and resistor R10.

[0039] The control terminal of the first transistor Q2 is connected to the output terminal of the first adjustment unit 111, and the first terminal of the first transistor Q2 is connected to the negative terminal of the LED string.

[0040] Furthermore, the second driving unit 12 includes: a second transistor Q4 and a second adjustment unit 121.

[0041] The first terminal of the second transistor Q4 is connected to the adjustment node of the first adjustment unit 111, and the second terminal of the second transistor Q4 is grounded.

[0042] The adjustment node of the second adjustment unit 121 is connected to the second terminal of the first transistor Q2; the first terminal of the second adjustment unit 121 is connected to the control terminal of the second transistor Q4, and the second terminal of the second adjustment unit 121 is grounded. In some embodiments, the second adjustment unit 121 may be composed of several resistors connected together, such as two resistors, three resistors, etc. Figure 2 The second adjustment unit 121 includes resistors R14 and R16.

[0043] When the LED string is working normally, the input terminal of the first adjustment unit 111 is connected to the open circuit protection module 40. The open circuit protection module 40 provides power to the first adjustment unit 111. After the first adjustment unit 111 performs voltage reduction processing, it controls the first transistor Q2 to conduct, and then controls the second transistor Q4 to conduct, so that the first transistor Q2 and the second transistor Q4 cooperate to achieve constant current output, so that the LED string can work.

[0044] When the LED string is open-circuited, it is detected by the LED open-circuit detection module 20 and fed back to the open-circuit protection module 40 by the fault feedback module 30. The open-circuit protection module 40 then stops supplying power to the first adjustment unit 111, thereby stopping all LED driver modules 10 from working, thus protecting the LED string and preventing further damage to the LED string.

[0045] See Figure 3 The following describes any of the above-mentioned LED open-circuit detection modules 20: The LED open-circuit detection module 20 includes: a first resistor R7, a second resistor R5, a third transistor Q5, and a first diode D2.

[0046] The first terminal of the first resistor R7 is connected to the output terminal of the LED string.

[0047] The first end of the second resistor R5 is connected to the input terminal of the LED string.

[0048] The control terminal of the third transistor Q5 is connected to the second terminal of the first resistor R7, the first terminal of the third transistor Q5 is connected to the second terminal of the second resistor R5, and the second terminal of the third transistor Q5 is grounded.

[0049] The positive terminal of the first diode D2 is connected to the first terminal of the third transistor Q5, and the negative terminal of the first diode D2 is connected to the aforementioned fault feedback module 30.

[0050] When the LED string is working normally, the third transistor Q5 is in the on state, and the voltage at the positive terminal of the first diode D2 is low. Based on this, the open circuit detection signal sent to the fault feedback module 30 is a low level signal.

[0051] When the LED string is open, the third transistor Q5 is in the off state. Since the first end of the second resistor R5 is connected to the input terminal of the LED string, the voltage of the positive terminal of the first diode D2 is high. Based on this, the open circuit detection signal sent to the fault feedback module 30 is a high-level signal.

[0052] The aforementioned fault feedback module 30 is connected to the LED open circuit detection module 20. When the open circuit detection signal is a high-level signal, it outputs a fault feedback signal to the open circuit protection module 40. The open circuit protection module 40 then stops supplying power to the LED driver module 10, thereby causing all LED driver modules 10 to stop working, thus protecting the LED string and preventing further damage to the LED string.

[0053] See Figure 4 The fault feedback module 30 includes a third drive unit 31 and a fourth drive unit 32.

[0054] The first end of the third driving unit 31 is connected to each LED open circuit detection module 20 as the input end of the fault feedback module 30. The second end of the third driving unit 31 is connected to the open circuit protection module 40 as the output end of the fault feedback module 30. The second end of the third driving unit 31 is connected to the input end of the LED string through the third resistor R4.

[0055] The first end of the fourth drive unit 32 is connected to the first end of the third drive unit 31, the second end of the fourth drive unit 32 is connected to the third end of the third drive unit 31, and the third and fourth ends of the fourth drive unit 32 are grounded.

[0056] When the LED string is working normally, the second terminal of the third driving unit 31 outputs a high-level fault feedback signal FB to the open circuit protection module 40, and the open circuit protection module 40 maintains the operation of supplying power to the LED driving module 10.

[0057] When the LED string is in an open circuit, the second terminal of the third driving unit 31 outputs a low-level fault feedback signal FB to the open circuit protection module 40. The open circuit protection module 40 then stops supplying power to the LED driving module 10, thereby stopping all LED driving modules 10 from working, thus protecting the LED string and preventing further damage to the LED string.

[0058] Furthermore, the third driving unit 31 includes a fourth resistor R9 and a fourth transistor Q1.

[0059] The first end of the fourth resistor R9 is connected to each LED open circuit detection module 20.

[0060] The control terminal of the fourth transistor Q1 is connected to the second terminal of the fourth resistor R9, and the first terminal of the fourth transistor Q1 is connected to the open circuit protection module 40.

[0061] Furthermore, the fourth driving unit 32 includes: a fifth transistor Q8, a fifth resistor R13, and a sixth resistor R18.

[0062] The first terminal of the fifth transistor Q8 is connected to the first terminal of the fourth resistor R9, and the second terminal of the fifth transistor Q8 is grounded.

[0063] The first end of the fifth resistor R13 is connected to the control terminal of the fifth transistor Q8, and the second end of the fifth resistor R13 is connected to the second terminal of the fourth transistor Q1.

[0064] The first end of the sixth resistor R18 is connected to the second end of the fifth resistor R13, and the second end of the sixth resistor R18 is grounded.

[0065] In some embodiments, when the LED string is operating normally, the fourth transistor Q1 is not turned on, and the fault feedback signal FB is high; when the LED string is open, the fourth transistor Q1 is turned on, and the fault feedback signal FB is low. Because fault feedback is provided by the high or low level of the fault feedback signal FB, the open-circuit protection module 40 receives the fault feedback signal FB to determine whether the LED string is open; when the fault feedback signal FB is high, the LED string is operating normally; when the fault feedback signal FB is low, the LED string is open.

[0066] See Figure 5 The open-circuit protection module 40 includes: a first control unit 41 and a second control unit 42.

[0067] The first terminal of the first control unit 41 is connected to the power supply Vin, and the second terminal of the first control unit 41 is connected to each LED driver module 10, providing the voltage Vin_OPEL to each LED driver module 10.

[0068] The control terminal of the second control unit 42 is connected to the fault feedback module 30. The first terminal of the second control unit 42 is connected to the control terminal of the first control unit 41. The second terminal of the second control unit 42 is grounded. When the second control unit 42 receives a fault feedback signal, it controls the first control unit 41 to disconnect from the LED driver module 10 and stop supplying power to the LED driver module 10.

[0069] Furthermore, the first control unit 41 includes: a sixth transistor M1, a first voltage divider unit 411, and a Zener diode D1.

[0070] The first terminal of the sixth transistor M1 is connected to the power supply, and the second terminal of the sixth transistor M1 is connected to each LED driver module 10.

[0071] The first terminal of the first voltage divider unit 411 is connected to the power supply, the second terminal of the first voltage divider unit 411 is connected to the first terminal of the second control unit 42, and the voltage divider node of the first voltage divider unit 411 is connected to the control terminal of the sixth transistor M1. The first voltage divider unit 411 includes resistors R6 and R12.

[0072] The negative terminal of Zener diode D1 is connected to the power supply, and the positive terminal of Zener diode D1 is connected to the voltage divider node of the first voltage divider unit 411.

[0073] Furthermore, the second control unit 42 includes: a second diode D4, a seventh resistor R19, and a seventh transistor Q9.

[0074] The positive terminal of the second diode D4 is connected to the fault feedback module 30.

[0075] The first terminal of the seventh resistor R19 is connected to the negative terminal of the second diode D4.

[0076] The control terminal of the seventh transistor Q9 is connected to the second terminal of the seventh resistor R19, the first terminal of the seventh transistor Q9 is connected to the control terminal of the first control unit 41, and the second terminal of the seventh transistor Q9 is grounded.

[0077] In some embodiments, the fault feedback signal FB is high when the LED string is in normal operation, the seventh transistor Q9 is turned on, the sixth transistor M1 is turned on, and the power supply Vin outputs the voltage Vin_OPEL through the sixth transistor M1 to enable the LED driver module 10 to work.

[0078] When the fault feedback signal FB is in the open circuit state of the LED string, the level is low, the seventh transistor Q9 is not conducting, the sixth transistor M1 is not conducting, the power supply Vin cannot enable the LED driver module 10 to work through the output voltage Vin_OPEL of the sixth transistor M1, the LED driver module 10 does not work, all LED driver modules 10 are turned off, and all LED strings are turned off.

[0079] See Figure 6 , Figure 6 This is a schematic diagram of another embodiment of the LED open-circuit protection circuit provided in this application.

[0080] Each LED string corresponds to one of the aforementioned LED driver module 10 and LED open-circuit detection module 20. For example... Figure 6 As shown, resistors R1 and R10, the second transistor Q4, resistors R14 and R16, and the first transistor Q2 constitute the LED driver module 10 corresponding to a set of LED strings. The first resistor R7, the second resistor R5, the third transistor Q5, and the first diode D2 constitute the LED open-circuit detection module 20 corresponding to a set of LED strings. The following explanation uses the second transistor Q4 and the first transistor Q2 as examples of transistors: Among them, the core of the constant current drive of the first transistor Q2 is to stabilize the LED current by using a negative feedback mechanism. The constant current output is achieved by adjusting the working state of the first transistor Q2 (amplification region or saturation region). The reference for current feedback is that the voltage Vbe of the second transistor Q4 is constant. A resistor is added between be to satisfy Ohm's law, I=V / R, to keep the LED current constant.

[0081] Furthermore, such as Figure 6 As shown, resistor R2, resistor R11, transistor Q3, resistor R15, resistor R17, and transistor Q6 constitute the LED driver module 10 corresponding to another set of LED strings. Resistor R8, resistor R3, transistor Q7, and diode D3 constitute the aforementioned LED open-circuit detection module 20 corresponding to another set of LED strings.

[0082] Taking the third transistor Q5 as an example: A discrete open-circuit detection circuit is built using transistors. The negative terminal of the LED bead is connected to the base of the third transistor Q5. Under normal LED string conditions, the base voltage of the third transistor Q5 is high, and Q5 is conducting, resulting in a low collector voltage. When the LED string is open-circuited, the base voltage of the third transistor Q5 is low, meaning Q5 is off-conducting, and its collector voltage is high. The voltage at the collector of the third transistor Q5 determines whether the LED bead is open-circuited. A low collector voltage indicates the corresponding LED string is working normally; a high collector voltage indicates an open circuit. The diodes (such as D3 and D2) in each LED open-circuit detection module prevent interference between the different open-circuit detection circuits.

[0083] Furthermore, such as Figure 6As shown, the fourth resistor R9, the fourth transistor Q1, the fifth transistor Q8, the fifth resistor R13, the sixth resistor R18, and the third resistor R4 constitute the aforementioned fault feedback module 30. Taking the fourth transistor Q1 and the fifth transistor Q8 as examples: Under normal LED string operation, the base of the fourth transistor Q1 is at a low level, the fourth transistor Q1 is not conducting, and the fault feedback signal FB is high; under open-circuit LED string operation, the base of the fourth transistor Q1 is at a high level, the fourth transistor Q1 is conducting, and the fault feedback signal FB is low; because fault feedback is provided through high and low levels, the open-circuit protection module 40 receives the fault feedback signal FB to determine if there is an open circuit in the LED string; when the fault feedback signal FB is high, the LED string is operating normally; when the fault feedback signal FB is low, the LED string is open.

[0084] Furthermore, such as Figure 6 As shown, the sixth transistor M1, resistors R6 and R12, Zener diode D1, second diode D4, seventh resistor R19, and seventh transistor Q9 constitute the aforementioned open-circuit protection module 40. Taking the seventh transistor Q9 as a transistor and the sixth transistor M1 as a MOSFET as an example: the fault feedback module feeds back a fault feedback signal FB to the open-circuit protection module, which can cut off the input power supply to protect the LED string when an open-circuit fault occurs. Specifically, the fault feedback signal FB is high when the LED string is in normal operation, connected to the base of the seventh transistor Q9. The seventh transistor Q9 is turned on, and the sixth transistor M1 is turned on. The power supply Vin outputs the voltage Vin_OPEL from the sixth transistor M1 to enable the LED driver module to work. When the LED string is in an open-circuit state, the fault feedback signal FB is low, connected to the base of the seventh transistor Q9. The seventh transistor Q9 is not turned on, and the sixth transistor M1 is not turned on. The power supply Vin cannot output the voltage Vin_OPEL from the sixth transistor M1 to enable the LED driver module 10 to work. The LED driver module 10 does not work, all LED driver modules 10 are turned off, and all LED strings are turned off.

[0085] See Figure 7 , Figure 7 This is a schematic diagram of a lighting assembly according to an embodiment of the present application. The lighting assembly 200 includes: at least one set of LED strings 201 and an LED open-circuit protection circuit 100.

[0086] It can be understood that the number of LED driver modules 10 and LED open circuit detection modules 20 in the LED open circuit protection circuit 100 corresponds one-to-one with the number of LED light strings 201.

[0087] See Figure 8 , Figure 8This is a structural schematic diagram of an embodiment of the vehicle provided in this application. The vehicle 300 includes an LED open-circuit protection circuit 100.

[0088] See Figure 9 , Figure 9 This is a structural schematic diagram of an embodiment of the vehicle provided in this application. The vehicle 300 includes a lighting assembly 200.

[0089] In summary, the LED open-circuit protection circuit 100 built using passive devices in this application does not require chips or MCUs. When any group of LED strings is detected to be open-circuited, the LED open-circuit protection circuit 100 automatically shuts off the power to all LED driver modules 10 without the need for the MCU to make any decisions, thus protecting the LED strings.

[0090] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of circuits or units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0091] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0092] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0093] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An LED open-circuit protection circuit, characterized in that, The LED open-circuit protection circuit includes: At least one LED driver module, each of the LED driver modules being connected to a set of LED light strings for driving the LED light strings to work; At least one LED open circuit detection module, each of which is connected to a set of LED strings to generate a corresponding open circuit detection signal; The fault feedback module is connected to the LED open circuit detection module and is used to output a fault feedback signal when the open circuit detection signal indicates that the LED string is open. An open-circuit protection module is connected to the fault feedback module and each of the LED driver modules respectively. When the fault feedback signal is received, the module disconnects from the LED driver module and stops supplying power to the LED driver module.

2. The LED open-circuit protection circuit according to claim 1, characterized in that, Each of the LED driver modules includes: A first driving unit, the first end of which is connected to the open circuit protection module, and the second end of which is connected to the output end of the LED string; The second driving unit has a first end connected to the third end of the first driving unit, a second end connected to the fourth end of the first driving unit, and the third and fourth ends of the second driving unit are grounded.

3. The LED open-circuit protection circuit according to claim 2, characterized in that, The first driving unit includes: The first adjustment unit, the input terminal of which is connected to the open circuit protection module; The first transistor has its control terminal connected to the output terminal of the first adjustment unit, and its first terminal connected to the negative terminal of the LED string. The second drive unit includes: The second transistor has its first terminal connected to the adjustment node of the first adjustment unit, and its second terminal grounded. The second adjustment unit has an adjustment node connected to the second terminal of the first transistor; the first terminal of the second adjustment unit is connected to the control terminal of the second transistor, and the second terminal of the second adjustment unit is grounded.

4. The LED open-circuit protection circuit according to claim 1, characterized in that, Each of the LED open-circuit detection modules includes: A first resistor, the first end of which is connected to the output terminal of the LED string; The second resistor has its first end connected to the input terminal of the LED string; The third transistor has its control terminal connected to the second terminal of the first resistor, its first terminal connected to the second terminal of the second resistor, and its second terminal grounded. The first diode has its anode connected to the first terminal of the third transistor, and its cathode connected to the fault feedback module.

5. The LED open-circuit protection circuit according to claim 1, characterized in that, The fault feedback module includes: The third driving unit has a first end that serves as the input terminal of the fault feedback module and is connected to each of the LED open circuit detection modules. The second end of the third driving unit serves as the output terminal of the fault feedback module and is connected to the open circuit protection module. The second end of the third driving unit is connected to the input terminal of the LED string through a third resistor. A fourth driving unit, wherein the first end of the fourth driving unit is connected to the first end of the third driving unit, the second end of the fourth driving unit is connected to the third end of the third driving unit, and the third and fourth ends of the fourth driving unit are grounded.

6. The LED open-circuit protection circuit according to claim 5, characterized in that, The third drive unit includes: The fourth resistor, the first end of which is connected to each of the LED open-circuit detection modules, The fourth transistor has its control terminal connected to the second terminal of the fourth resistor, and its first terminal connected to the open-circuit protection module. The fourth drive unit includes: The fifth transistor has its first terminal connected to the first terminal of the fourth resistor, and its second terminal grounded. The fifth resistor has its first end connected to the control terminal of the fifth transistor, and its second end connected to the second terminal of the fourth transistor. The sixth resistor has its first end connected to the second end of the fifth resistor, and its second end is grounded.

7. The LED open-circuit protection circuit according to claim 1, characterized in that, The open-circuit protection module includes: A first control unit, a first terminal of which is connected to a power supply, and a second terminal of which is connected to each of the LED driver modules; The second control unit has its control terminal connected to the fault feedback module, its first terminal connected to the control terminal of the first control unit, and its second terminal grounded. When the second control unit receives the fault feedback signal, it controls the first control unit to disconnect from the LED driver module and stop supplying power to the LED driver module.

8. The LED open-circuit protection circuit according to claim 7, characterized in that, The first control unit includes: A sixth transistor, the first terminal of which is connected to the power supply, and the second terminal of which is connected to each of the LED driver modules; A first voltage divider unit, the first end of which is connected to the power supply, the second end of which is connected to the first end of the second control unit, and the voltage divider node of which is connected to the control terminal of the sixth transistor; A Zener diode, the negative terminal of which is connected to the power supply, and the positive terminal of which is connected to the voltage divider node of the first voltage divider unit.

9. The LED open-circuit protection circuit according to claim 7, characterized in that, The second control unit includes: The second diode, the positive terminal of which is connected to the fault feedback module; A seventh resistor, the first end of which is connected to the negative terminal of the second diode; The seventh transistor has its control terminal connected to the second terminal of the seventh resistor, its first terminal connected to the control terminal of the first control unit, and its second terminal grounded.

10. A lighting assembly, characterized in that, The lighting assembly includes: at least one set of LED strings and an LED open-circuit protection circuit as described in any one of claims 1-9.

11. A vehicle, characterized in that, The vehicle includes an LED open-circuit protection circuit as described in any one of claims 1-9, or includes a lighting assembly as described in claim 10.

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