LED driving circuit capable of supporting high-load working condition fault feedback
By configuring appropriate base current and voltage regulation circuit, an LED driver circuit capable of supporting high load conditions was designed, solving the problem that transistor-type constant current drive circuits cannot effectively provide fault feedback under high load current, and realizing stable driving of LED loads and vehicle body fault diagnosis.
Patent Information
- Application Number
- CN202423096482.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-16
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-12-16
AI Technical Summary
Existing transistor-type constant current drive circuits cannot effectively diagnose vehicle body faults through low current feedback under high load current conditions, affecting the normal operation of lamps. Furthermore, increasing the base current will cause the open circuit current diagnosis in fault mode to fail.
An LED driver circuit was designed, which includes an input processing circuit, a constant current output circuit, a fault diagnosis circuit, and a feedback execution circuit. By detecting the voltage of each LED load and configuring appropriate base current and voltage regulation circuit, the circuit can be driven with constant current within the normal operating voltage range, and a very low current can be fed back for vehicle body diagnosis in case of fault.
Under high load current conditions, it achieves stable LED load lighting and vehicle body fault diagnosis, avoiding the problem of current diagnosis failure of conventional transistor circuits under high load. The structure is simple and the cost is well controlled.
Smart Images
Figure CN223600058U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of car light illumination, especially to a LED drive circuit capable of supporting high load working condition fault feedback. BACKGROUND
[0002] With the change of automobile market, the requirement of automobile parts to cost is higher and higher. The hard-wire circuit structure using triode as constant current drive is simple and stable, has great cost advantage, and thus has its unique use value. For the consideration of safety, fault feedback has become indispensable. For the hard-wire circuit, the current detection fault is most commonly used at present, that is, when the lamp appears fault (not bright), a small current value (such as <10mA) is fed back to realize alarm through the body BCM diagnosis. The triode has three working states: cutoff area, amplification area and saturation area. For the car light circuit, the working voltage is usually 9-16V, and the rated voltage is 13.5V. At this time, the triode circuit works in the amplification area. The output current Ic of the triode is βIb. After setting the current through the resistor to be minimum at 9V, the total base current Ib of all triodes is the current through the resistor minus the current on the stabilizing tube. Thus, the total maximum output current of all triodes is Ic=βIb. When there is greater demand for lamp brightness, the current required by the LED load will increase, which requires a low minimum base current at low voltage. When the base current is too low, the constant current capability of the triode constant current drive circuit will be greatly weakened, and the output current at low voltage will be greatly reduced, which seriously affects the normal work of the lamp. Increasing the base current will increase the current in the N-1 fault state, which will cause the current fault detection of the vehicle body to fail. That is, in the existing technology, the triode constant current drive circuit is used, and the open circuit fault is diagnosed by using current diagnosis, which often has strict restrictions on the current size in the N-1 state, such as not more than 10mA. The conventional triode constant current circuit needs to work in the amplification area of the triode to realize its constant current drive capability. Therefore, the output capacity is proportional to the base current value of the triode. The increased base current will affect the open circuit current diagnosis in the fault mode. This affects the driving capacity of the existing scheme for large current LED load.
[0003] Therefore, it is necessary to provide a LED drive circuit capable of supporting high load working condition fault feedback. UTILITY MODEL CONTENTS
[0004] The utility model aims at providing a LED drive circuit capable of supporting high load working condition fault feedback, and aims at solving the problem that in the prior art, when N-1 fault occurs under large load current, the fault diagnosis of the vehicle body cannot be realized through low current feedback.
[0005] The utility model discloses an embodiment provides a kind of LED drive circuit that can support high load operating condition fault feedback, including input processing circuit, constant current output circuit, LED load, fault diagnosis circuit and feedback execution circuit in the LED drive circuit;The input processing circuit is externally connected with body control module, connects body power input, for providing anti-reverse protection and filtering interference for LED drive circuit;The input end of the constant current output circuit is electrically connected with the output end of the input processing circuit, and the output end of the constant current output circuit is electrically connected with the LED load, and the constant current output circuit is used to provide constant current drive for the LED load;The LED load adopts multiple LED parallel connection;The input end of the fault diagnosis circuit is connected to the output end of the LED load, and the output end of the fault diagnosis circuit is electrically connected with the input end of the feedback execution circuit, and the fault diagnosis circuit is used to monitor the working state of each LED load, and when any LED damage open-circuit fault is monitored, feedback fault signal is fed back to the feedback execution circuit;The output end of the feedback execution circuit is electrically connected with the input end of the constant current output circuit, for closing constant current output circuit and feeding back a working current to realize the fault detection of vehicle body after receiving the fault signal.
[0006] Further, the input processing circuit includes: transformer T1, first capacitor C1, second capacitor C2 and first resistor R1 which are parallel to each other, and first diode D1 which is connected in series with the input processing circuit, and the body power supply VCC filters the harmonic and pulse interference after passing through the input processing circuit, and provides anti-reverse protection for the LED drive circuit.
[0007] Further, the constant current output circuit uses a transistor circuit to provide configurable constant current drive for the LED load.
[0008] Further, the constant current output circuit includes a voltage stabilizing device D2, and the voltage stabilizing device D2 is a double series switch diode.
[0009] Further, the constant current output circuit further includes first transistor Q1, second transistor Q2, third transistor Q3, fourth transistor Q4 and sampling resistor, the sampling resistor includes third resistor R3, fourth resistor R4, fifth resistor R5, eighth resistor R8 and ninth resistor R9, the double series switch diode is connected in parallel between the base of the first transistor Q1 and GND, the fourth resistor R4 is connected in series at the emitter of the first transistor Q1, the fifth resistor R5 is connected in series at the emitter of the second transistor Q2, the eighth resistor R8 is connected in series at the emitter of the third transistor Q3, the ninth resistor R9 is connected in series at the emitter of the fourth transistor Q4, and the third resistor is arranged between the first transistor Q1 and the voltage stabilizing device D2, the sampling resistor is configured according to the demand of the load, and the multiple transistors in parallel are selected according to the power that the transistor bears, to provide constant current drive for the load.
[0010] Further, the constant current output circuit further comprises a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8, the fourth capacitor C4 is connected in parallel with the voltage stabilizing device D2, one end of the fifth capacitor C5 is connected to the base of the first triode Q1, and the other end is grounded, one end of the sixth capacitor C6 is connected to the base of the second triode Q2, and the other end is grounded, one end of the seventh capacitor C7 is connected to the base of the third triode Q3, and the other end is grounded, one end of the eighth capacitor C8 is connected to the base of the fourth triode Q4, and the other end is grounded.
[0011] Further, the fault diagnosis circuit is connected to each LED load respectively, and provides a separate monitoring circuit for each LED load.
[0012] Further, the fault diagnosis circuit comprises a sixth triode Q6, a fourth diode D4, a tenth resistor R10 and an eleventh resistor R11, the tenth resistor R10 is connected to the base of the sixth triode Q6, the emitter of the sixth triode Q6 is grounded, the fourth diode D4 is connected to the collector of the sixth triode Q6, and the eleventh resistor R11 is connected to the collector of the sixth triode Q6, when the LED load works normally, the input potential of the tenth resistor R10 is greater than the sixth triode Q6, and the sixth triode Q6 is in an open state.
[0013] Further, the feedback execution circuit comprises a base resistor R2, a third capacitor C3 and a PMOS tube M1, the third capacitor C3 and the PMOS tube M1 are connected in parallel and then connected in series to the base resistor R2, after receiving the fault signal, the feedback execution circuit switches the working state of the circuit through the PMOS tube M1, and closes the base current input of all triode circuits.
[0014] Further, the feedback execution circuit is also used for managing the base current of the constant current output circuit, and when receiving the fault signal, the current output of the constant current output circuit is closed, so that the total current consumption of the circuit is reduced to a preset threshold value that can satisfy the vehicle body current detection.
[0015] The beneficial effect brought by the technical scheme provided by the embodiment of the utility model is that the application provides an LED drive circuit capable of supporting high load working condition fault feedback: for the condition of multiple LED parallel connection, the end of each LED load is subjected to voltage detection, when LED open circuit fault occurs, the voltage at the end of the LED load changes from high to low, the control circuit enters N-1 state, all LED branches are closed, and a very low current is fed back to realize vehicle body diagnosis alarm. Even when the LED load current is large, by configuring the base resistance value of the triode to adjust the appropriate base current, the circuit is ensured to always work in amplification state within the normal working voltage range 9-16V of the vehicle lamp, and the constant output current of the LED under different working voltages is maintained through the voltage stabilizing circuit of the branch, so that the stable lighting effect of the lamp is ensured. At the same time, the base current of the triode under normal working condition is controlled when fault feedback occurs, so that the vehicle body fault diagnosis can be realized through low current feedback under the condition of N-1 fault under large load current. The scheme has simple and stable structure, outstanding cost control, and is a good choice in the hard-wired scheme. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.
[0017] Figure 1 It is a structure schematic diagram of the LED drive circuit capable of supporting high load working condition fault feedback provided by the embodiment of the utility model.
[0018] Figure 2 It is a whole topology diagram of the LED drive circuit capable of supporting high load working condition fault feedback provided by the embodiment of the utility model.
[0019] Figure 3 It is an input processing circuit topology diagram provided by the embodiment of the utility model.
[0020] Figure 4 It is a constant current output circuit topology diagram provided by the embodiment of the utility model.
[0021] Figure 5 It is a fault diagnosis circuit topology diagram provided by the embodiment of the utility model.
[0022] Figure 6 It is a feedback execution circuit topology diagram provided by the embodiment of the utility model.
[0023] Figures 7-8The utility model embodiment provides a kind of topology graph of prior art LED drive circuit.
[0024] Figure 9 The utility model embodiment provides a kind of base resistance is When the current schematic diagram of flowing through each component. Specific implementation
[0025] So that the purpose, technical scheme and advantage of the utility model are more clear, the utility model embodiment will be further detailed below with the attached drawings.
[0026] Unless otherwise defined, all technical and scientific terms used herein are the same as the meanings understood by one of ordinary skill in the art to which the utility model belongs; The terms used in the specification are only for the purpose of describing the specific embodiments, and are not intended to limit the utility model, for example, the terms "length", "width", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", "upper end", "lower end", "middle" and the like indicate the orientation or position based on the orientation or position shown in the drawings, only for the convenience of description, and cannot be understood as the limitation of the technical scheme.
[0027] The terms "include" and "have" and any variations thereof in the specification and claims of the utility model and the above drawing description are intended to cover non-exclusive inclusion; The terms "first", "second" and the like in the specification and claims of the utility model or the above drawings are used to distinguish different objects, and are not used to describe a specific order. The meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited.
[0028] In addition, referring to "embodiment" in this paper means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the utility model. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is not mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0029] Embodiment
[0030] For the subsequent understanding, the overall inventive concept of the utility model is explained here: the utility model provides a LED drive circuit of fault feedback that can support high load working condition: for the condition of multiple LED parallel connection, the end of each LED load is detected, when LED open circuit fault occurs, the voltage of LED load end changes from high to low, the control circuit enters N-1 state, all LED branches are closed, and a very low current is fed back to realize vehicle body diagnosis alarm. Even when the LED load current is large, by configuring the base resistance value of the triode to adjust the appropriate base current, the circuit is always working in amplification state within the normal working voltage range of vehicle lamp 9-16V, and through the voltage stabilizing circuit of the branch, the LED output current is kept constant under different working voltages, and the stable lighting effect of the lamp is ensured. At the same time, the base current of the triode in the normal working state is controlled when fault feedback occurs, so that in the case of N-1 fault under large load current, the fault diagnosis of the vehicle body can still be realized through low current feedback normally. The scheme has simple and stable structure, outstanding cost control, and is a good choice in hard-wired scheme.
[0031] The specific implementation is as follows:
[0032] As shown in Figures 1-2 It is a LED drive circuit structure schematic diagram of the utility model embodiment that can support high load working condition fault feedback.
[0033] As an example, the LED drive circuit includes input processing circuit 1, constant current output circuit 2, LED load 3, fault diagnosis circuit 4 and feedback execution circuit 5; the input processing circuit 1 is externally connected with body control module (BCM) 6, connected with vehicle body power supply input, used for providing anti-reverse protection and filtering interference for the LED drive circuit; the input end of the constant current output circuit 2 is electrically connected with the output end of the input processing circuit 1, the output end of the constant current output circuit 2 is electrically connected with the LED load 3, and the constant current output circuit 2 is used for providing constant current drive for the LED load 3; the LED load 3 adopts multiple LED parallel connection; the input end of the fault diagnosis circuit 4 is connected with the output end of the LED load 3, the output end of the fault diagnosis circuit 4 is electrically connected with the input end of the feedback execution circuit 5, and the fault diagnosis circuit 4 is used for monitoring the working state of each LED load 3, and feeding back fault signal to the feedback execution circuit 5 when any LED damage open circuit fault is monitored; the output end of the feedback execution circuit 5 is electrically connected with the input end of the constant current output circuit 2, used for closing the constant current output circuit 2 and feeding back a working current to realize vehicle body fault detection after receiving the fault signal.
[0034] In some feasible embodiments, in combination Figure 3As shown, the input processing circuit 1 includes a transformer T1, a first capacitor C1, a second capacitor C2 and a first resistor R1 connected in parallel with each other, and a first diode D1 connected in series therewith, and the vehicle body power supply VCC is filtered of harmonic and impulse interference after passing through the input processing circuit, and the LED driving circuit is provided with reverse connection protection.
[0035] In some possible embodiments, the constant current output circuit 2 uses a triode circuit to provide configurable constant current driving for the LED load 3.
[0036] In some possible embodiments, in combination with Figure 4As shown, the constant current output circuit 2 includes a voltage stabilizing device D2, which is a double series switch diode. The constant current output circuit 2 also includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, and a sampling resistor, which includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, an eighth resistor R8, and a ninth resistor R9. The double series switch diode is connected in parallel between the base of the first transistor Q1 and GND. The fourth resistor R4 is connected in series at the emitter of the first transistor Q1. The fifth resistor R5 is connected in series at the emitter of the second transistor Q2. The eighth resistor R8 is connected in series at the emitter of the third transistor Q3. The ninth resistor R9 is connected in series at the emitter of the fourth transistor Q4. The third resistor is disposed between the first transistor Q1 and the voltage stabilizing device D2. The sampling resistor is configured according to the requirements of the load. According to the power borne by the transistors, multiple transistors are selected in parallel to output, so as to provide constant current driving for the load. The constant current output circuit 2 also includes a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, and an eighth capacitor C8. The fourth capacitor C4 is connected in parallel with the voltage stabilizing device D2. One end of the fifth capacitor C5 is connected to the base of the first transistor Q1, and the other end is grounded. One end of the sixth capacitor C6 is connected to the base of the second transistor Q2, and the other end is grounded. One end of the seventh capacitor C7 is connected to the base of the third transistor Q3, and the other end is grounded. One end of the eighth capacitor C8 is connected to the base of the fourth transistor Q4, and the other end is grounded. Specifically, when the voltage stabilizing device D2 is normally turned on, a constant reference potential V1 that does not fluctuate with the input voltage can be provided for the bases of all the transistors. It should be noted that the voltage stabilizing device can also use other forms of voltage stabilizing devices. The base resistor R2 is used to provide a suitable base current to turn on all the transistors. A constant voltage is obtained from the voltage stabilizing device D2 connected in parallel to the base. When the transistors (Q1, Q2, Q3, Q4) are turned on, the sampling resistor (R4, R5, R8, R9) connected in series at the emitter of the transistors will obtain a constant voltage of (V1-Vbe). According to the requirements of the load, a suitable sampling resistor is configured. According to the power borne by the devices, mainly the power borne by the transistors, multiple transistors are selected in parallel to output, so as to provide suitable constant current driving for the load.
[0037] In some possible implementations, the fault diagnosis circuit 4 is separately connected to each LED load 3, so as to provide a separate monitoring circuit for each LED load 3.
[0038] In some possible implementations, the fault diagnosis circuit 4 is combined with Figure 5As shown, the fault diagnosis circuit 4 includes a sixth transistor Q6, a fourth diode D4, a tenth resistor R10 and an eleventh resistor R11, the tenth resistor R10 is connected to the base of the sixth transistor Q6, the emitter of the sixth transistor Q6 is grounded, the fourth diode D4 is connected to the collector of the sixth transistor Q6, and the eleventh resistor R11 is connected to the collector of the sixth transistor Q6. When the LED load is working normally, the input potential of the tenth resistor R10 is greater than the sixth transistor Q6, and the sixth transistor Q6 is in an open state. Specifically, the base of the transistor Q6 is connected to the resistor R10, the resistor R10 is connected to the negative electrode of the LED load, the collector of the transistor Q6 is pulled up to the power supply through the resistor R11, and the positive electrode of the diode D4 is connected. When the LED load is working normally, the input potential of the resistor R10 is greater than the transistor VTN, and the transistor Q6 is in an open state. It should be noted that the resistance values of the base resistor R10 and the pull-up resistor R11 are adjusted according to the amplification factor hfe of the transistor, so that the transistor works in a saturated state, Uce<0.7V, and the diode is in a cut-off state, and the negative electrode of the diode outputs low. When the LED load is open due to failure, the base voltage of the transistor is less than VTN, and the transistor is cut off. The collector potential of the transistor changes from low to high, and the diode is turned on. The diode outputs of the multi-path monitoring circuit are connected in parallel as the input of the feedback execution module.
[0039] In some possible embodiments, the feedback execution circuit is combined with Figure 6 As shown, the feedback execution circuit 5 includes a base resistor R2, a third capacitor C3 and a PMOS transistor M1, the third capacitor C3 and the PMOS transistor M1 are connected in parallel and then connected in series to the base resistor R2. After receiving the fault signal, the feedback execution circuit switches the working state of the circuit through the PMOS transistor M1, and closes the base current input of all transistor circuits. The feedback execution circuit 5 is also used to manage the base current of the constant current output circuit, and closes the current output of the constant current output circuit after receiving the fault signal, so that the total current consumption of the circuit is reduced to a preset threshold value that can satisfy the vehicle body current detection. Specifically, after receiving the fault signal, the working state of the circuit is switched through the PMOS transistor M1, and the base current input of all transistor circuits is closed. In order to achieve the N-1 requirement of extinguishing one LED and closing all LEDs, and to feedback a very low current to realize vehicle body fault detection. The current loss of the circuit in the N-1 state is mainly composed of the current of the fault diagnosis circuit of each path and the current of the discharge resistor of the input processing circuit, and the increase of the base current will not affect the current feedback of N-1. This makes the circuit can support the application working condition of high load current, and realizes the constant current driving of the LED in a larger range.
[0040] In some possible implementations, increasing the base current can effectively suppress the current attenuation problem at low voltage under large load conditions. However, the current consumption of the conventional triode circuit at N-1 will increase with the increase of the base current. This may violate the current diagnosis requirements of the vehicle body at 16V high voltage. As shown in Figures 7-8 , the N-1 current before and after the increase of the base current is compared respectively. As shown in Figure 7 , when the base resistance is set to 2 , the N-1 current is 8.5mA. As shown in Figure 8 , when the base resistance is set to 1 , the N-1 current has exceeded the 10mA threshold. Therefore, it can be proved that the use of the existing LED driving circuit will cause the current consumption at N-1 to increase with the increase of the base current.
[0041] In some possible implementations, as shown in Figure 9 , the above embodiment sets a fault diagnosis circuit in each load branch. When an open circuit fault occurs in any LED load branch, a feedback signal is fed back to the feedback execution circuit, and the base path of the triode is completely cut off, so that the normal base current will no longer affect the feedback current at N-1. Thus, a higher base current can be obtained, and a good constant current effect can be maintained in the range of 9-16V. And the low current value required by the vehicle body at N-1 is fed back. As shown in Figure 8 and Figure 9 , it can be seen that the N-1 current of the LED driving circuit described in the embodiment has met the 10mA detection threshold at 16V.
[0042] The above embodiment is aimed at the case of multiple parallel LED loads. The voltage at the end of each LED load is detected. When the LED is open-circuited, the voltage at the end of the LED load changes from high to low, the control circuit enters the N-1 state, all LED branches are closed, and a very low current is fed back to realize the vehicle body diagnosis alarm. Even when the LED load current is large, by configuring the base resistance value of the triode to adjust the appropriate base current, the circuit can always work in the amplification state in the normal working voltage range of 9-16V, and the LED output current is kept constant at different working voltages through the branch voltage stabilizing circuit, ensuring the stable lighting effect of the lamp. At the same time, the base current of the triode in the normal working state is controlled when a fault is fed back, so that in the case of large load current, the vehicle body fault diagnosis can still be realized through low current feedback when N-1 fault occurs. The scheme is simple and stable in structure, and the cost control is outstanding. It is a good choice in the hard-wired scheme. Moreover, the circuit is composed of independent devices such as diodes, triodes, MOS tubes and resistors, without using chips, and is simple to realize and stable in structure, without EMC problems, and the cost control is excellent.
[0043] The above merely describes a preferred embodiment of the present application, and the protection scope of the present application is not limited thereto, and any skilled person in the art, according to the technical scheme and the inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.
Claims
1. An LED driving circuit capable of supporting high load condition fault feedback, characterized in that, The LED driving circuit comprises an input processing circuit, a constant current output circuit, an LED load, a fault diagnosis circuit and a feedback execution circuit; The input processing circuit is connected with a vehicle body control module and a vehicle body power input, and is used for providing anti-reverse protection and filtering interference for the LED driving circuit; The input end of the constant current output circuit is electrically connected with the output end of the input processing circuit, and the output end of the constant current output circuit is electrically connected with the LED load, and the constant current output circuit is used for providing constant current driving for the LED load; The LED load adopts a plurality of LED parallel connection; The input end of the fault diagnosis circuit is connected with the output end of the LED load, the output end of the fault diagnosis circuit is electrically connected with the input end of the feedback execution circuit, and the fault diagnosis circuit is used for monitoring the working state of each LED load, and feeding back a fault signal to the feedback execution circuit when any LED is damaged and open circuit fault occurs; The output end of the feedback execution circuit is electrically connected with the input end of the constant current output circuit, and is used for closing the constant current output circuit and feeding back a working current to realize fault detection of the vehicle body when the fault signal is received.
2. The LED driving circuit capable of supporting high load condition fault feedback according to claim 1, characterized in that, The input processing circuit comprises a transformer T1, a first capacitor C1, a second capacitor C2 and a first resistor R1 which are connected in parallel with each other, and a first diode D1 connected in series with them, and the vehicle body power VCC filters harmonic and pulse interference through the input processing circuit, and provides anti-reverse protection for the LED driving circuit.
3. The LED driving circuit capable of supporting high load condition fault feedback according to claim 1, characterized in that, The constant current output circuit uses a triode circuit to provide configurable constant current driving for the LED load.
4. The LED driving circuit capable of supporting high load condition fault feedback according to claim 3, characterized in that, The constant current output circuit comprises a stabilizing device D2, and the stabilizing device D2 is a double series switch diode.
5. The LED driving circuit capable of supporting high load condition fault feedback according to claim 4, characterized in that, The constant current output circuit further comprises a first triode Q1, a second triode Q2, a third triode Q3, a fourth triode Q4 and a sampling resistor, the sampling resistor comprises a third resistor R3, a fourth resistor R4, a fifth resistor R5, an eighth resistor R8 and a ninth resistor R9, the double series switch diode is connected in parallel between the base of the first triode Q1 and GND, the fourth resistor R4 is connected in series at the emitter of the first triode Q1, the fifth resistor R5 is connected in series at the emitter of the second triode Q2, the eighth resistor R8 is connected in series at the emitter of the third triode Q3, the ninth resistor R9 is connected in series at the emitter of the fourth triode Q4, and the third resistor is arranged between the first triode Q1 and the stabilizing device D2, the sampling resistor is configured according to the requirement of the load, and a plurality of triodes are selected in parallel according to the power borne by the triode, so as to provide constant current driving for the load.
6. The LED driving circuit capable of supporting high load condition fault feedback according to claim 5, characterized in that, The constant current output circuit further comprises a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7 and an eighth capacitor C8, the fourth capacitor C4 is connected in parallel with the voltage stabilizing device D2, one end of the fifth capacitor C5 is connected to the base of the first triode Q1, and the other end is grounded, one end of the sixth capacitor C6 is connected to the base of the second triode Q2, and the other end is grounded, one end of the seventh capacitor C7 is connected to the base of the third triode Q3, and the other end is grounded, one end of the eighth capacitor C8 is connected to the base of the fourth triode Q4, and the other end is grounded.
7. The LED driving circuit capable of supporting high load condition fault feedback according to claim 1, characterized in that, The fault diagnosis circuit is connected with each LED load respectively, and provides a separate monitoring circuit for each LED load.
8. The LED driving circuit capable of supporting high load condition fault feedback according to claim 1, characterized in that, The fault diagnosis circuit comprises a sixth triode Q6, a fourth diode D4, a tenth resistor R10 and an eleventh resistor R11, the tenth resistor R10 is connected to the base of the sixth triode Q6, the emitter of the sixth triode Q6 is grounded, the fourth diode D4 is connected to the collector of the sixth triode Q6, and the eleventh resistor R11 is connected to the collector of the sixth triode Q6, when the LED load works normally, the input potential of the tenth resistor R10 is greater than the sixth triode Q6, and the sixth triode Q6 is in an open state.
9. The LED driving circuit capable of supporting high load condition fault feedback according to claim 1, characterized in that, The feedback execution circuit comprises a base resistor R2, a third capacitor C3 and a PMOS tube M1, the third capacitor C3 and the PMOS tube M1 are connected in parallel and then connected in series to the base resistor R2, after receiving the fault signal, the feedback execution circuit switches the working state of the circuit through the PMOS tube M1, and closes the base current input of all triode circuits.
10. The LED driving circuit capable of supporting high load condition fault feedback according to claim 1, characterized in that, The feedback execution circuit is also used for managing the base current of the constant current output circuit, and when receiving the fault signal, the current output of the constant current output circuit is closed, so that the total current consumption of the circuit is reduced to a preset threshold value that can satisfy the vehicle body current detection.