LED drive circuit for in-vehicle atmosphere lamp

Abstract

The utility model discloses an LED drive circuit used for an in-vehicle atmosphere lamp, comprising an SBC chip, the SBC chip is provided with an LED constant current terminal group, the LED constant current terminal group is connected with at least one LED constant current drive circuit, and each LED constant current drive circuit is connected with an LED lamp group. The beneficial effects of the utility model are that when the number of LEDs is increased, the number of driving chips is not increased, the circuit cost is reduced, heat is uniformly distributed on the PCB, and the service life of the PCB is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of automotive lighting technology, and in particular to an LED driver circuit for in-vehicle ambient lighting. Background Technology

[0002] With the development of new energy vehicles, the development of in-car ambient lighting is also advancing rapidly, no longer satisfied with the simple functions of traditional single-color light on and off. The demand for multi-color gamut and multi-LED lighting is now experiencing explosive growth.

[0003] As customers increase their requirements for color and functionality, such as requiring 128 colors, 256 colors, independent display for each area, and color changes in sync with the rhythm of music, it is necessary to increase the number of LEDs and LED driver chips on the PCB accordingly.

[0004] like Figure 1 As shown in the patent document with application number CN202410723309, the LED driver circuit for automotive lighting circuit design includes an LED driver module. The output of this LED driver module is connected to multiple LED light groups. However, when the LED driver module is working, its power is very high, and its operating temperature is too high, causing localized overheating of the PCB and shortening its lifespan. Furthermore, the number of LED light groups is limited by the output of the LED driver module, meaning that adding more LED light groups inevitably increases the number of LED driver modules, thus increasing manufacturing costs.

[0005] like Figure 1 As shown, to reduce heat dissipation of the LED driver module, a DC-DC converter was added between the power supply and the voltage terminals of the LED driver module. This reduced the input voltage of the LED driver module, thereby decreasing its heat dissipation and preventing localized overheating of the PCB. However, the DC-DC module uses frequency modulation, making it difficult to pass tests such as radiated emission. Generally, modifications and re-testing are required to pass these tests, significantly delaying development time. Furthermore, adding the DC-DC module and its associated circuitry increases circuit costs, further increasing manufacturing costs. Utility Model Content

[0006] The purpose of this invention is to provide an LED driver circuit for in-vehicle ambient lighting that can increase the number of LEDs without increasing the number of driver chips, thereby reducing circuit costs and distributing heat evenly on the PCB, thus extending the PCB's lifespan.

[0007] A key feature of an LED driver circuit for vehicle interior ambient lighting is that it includes an SBC chip, which has an LED constant current terminal group connected to at least one LED constant current driver circuit, and each LED constant current driver circuit is connected to a group of LED lights.

[0008] In the circuit described above, the SBC chip is only used for control and consumes little current. Therefore, the SBC chip generates almost no heat during operation, thus extending its lifespan.

[0009] Meanwhile, the heat generated by the above circuit during operation is mainly concentrated in the LED constant current drive circuit. The components in the LED constant current drive circuit can be distributed on the PCB board, so that the heat is evenly distributed on the PCB board, thereby extending the service life of the PCB board.

[0010] Furthermore, the LED constant current driving circuit includes a transistor Q31, which is a PNP transistor. The base of transistor Q31 is connected to the LED constant current terminal group via resistor R40. The base of transistor Q31 is also connected to the power supply VS via resistor R37. The emitter of transistor Q31 is connected to the power supply VS. The collector of transistor Q31 is connected to the base of transistor Q28 via resistor R34. Transistor Q28 is an NPN transistor. The collector of transistor Q28 is connected to the LED lamp group. The emitter of transistor Q28 is grounded via resistor R43. The emitter of transistor Q28 is also connected to the base of transistor Q34, which is an NPN transistor. The collector of transistor Q34 is connected to the base of transistor Q28. The emitter of transistor Q34 is grounded.

[0011] When the LED constant current terminal outputs a low level, transistor Q31 conducts, and the constant current circuit composed of transistors Q28 and Q34 conducts. Transistors Q28 and Q34 clamp each other, gradually stabilizing the current flowing through the LED lamp group, thereby driving the LED lamp group with a constant current, keeping the brightness of the LED lamp group stable, uniformly adjusting the brightness and color of the LED lamp group, reducing the temperature rise of the LED lamp group, preventing overheating, delaying the light decay of the LED, and extending its service life.

[0012] Meanwhile, transistors Q31, Q28, and Q34 are distributed across the PCB board, ensuring even heat distribution and extending the PCB board's lifespan.

[0013] Furthermore, the LED assembly contains two light-emitting diodes (LEDs). The negative terminal of one LED is connected to the collector of the transistor Q28, the positive terminal of one LED is connected to the negative terminal of the other LED, and the positive terminal of the other LED is connected to the power supply VS.

[0014] Furthermore, the LED constant current terminal group is provided with LED constant current port HV0, LED constant current port HV1 and LED constant current port HV2;

[0015] Among them, the LED constant current port HV0 is connected to the LED lamp group with green light color through the LED constant current driving circuit;

[0016] LED constant current port HV1 is connected to the LED group with red light emission color via the LED constant current drive circuit;

[0017] The LED constant current port HV2 is connected to the blue LED group via the LED constant current drive circuit.

[0018] Green, red, and blue are the three primary colors of light. The SBC chip controls the opening and closing of the LED constant current ports HV0, HV1, and HV2 by controlling the duty cycle, thus mixing a variety of different colors to meet various lighting design needs.

[0019] Furthermore, each of the LED constant current ports HV0, HV1, and HV2 is connected to at least one of the LED constant current drive circuits.

[0020] Since the SBC chip is only used for control, each LED constant current port in the SBC chip can be cascaded with multiple LED constant current drive circuits. Therefore, without adding an SBC chip, LED light groups can be added arbitrarily to meet various lighting design needs.

[0021] Meanwhile, SBC chips, transistors, and light-emitting diodes are inexpensive and easy to procure, thereby reducing manufacturing costs.

[0022] Beneficial effects: 1. The SBC chip is only used for control in this utility model. Each LED constant current port in the SBC chip can be cascaded with multiple LED constant current drive circuits, thereby improving the expandability of this utility model. Without adding SBC chips, the number of LED light groups can be increased arbitrarily to meet various lighting design requirements.

[0023] Meanwhile, the SBC chip in this invention consumes little current and generates almost no heat, thereby extending the lifespan of the SBC chip.

[0024] 2. The heat generated during operation of this utility model is mainly concentrated in the LED constant current drive circuit. The components in the LED constant current drive circuit can be distributed on the PCB board, so that the heat is evenly distributed on the PCB board, thereby extending the service life of the PCB board.

[0025] 3. The LED constant current drive circuit can drive the LED lamp group with constant current, so that the brightness of the LED lamp group remains stable, the brightness and color of the LED lamp group are uniform, the temperature rise of the LED lamp group is reduced, the LED lamp group is prevented from overheating, the light decay of the LED is delayed, and its service life is extended.

[0026] 4. The SBC chip, transistor and light-emitting diode are not only inexpensive but also easy to procure, thus greatly reducing the manufacturing cost of this utility model. Attached Figure Description

[0027] Figure 1 LED driver circuit diagram for use in automotive lighting circuit design;

[0028] Figure 2 This is the circuit diagram of this utility model;

[0029] Figure 3 Diagram of cascaded LED constant current drive circuit for HV0 constant current port;

[0030] Figure 4 This is a circuit diagram of a cascaded LED constant current drive circuit using the HV1 constant current port.

[0031] Figure 5 This is a circuit diagram of a cascaded LED constant current drive circuit using the HV2 constant current port. Detailed Implementation

[0032] The specific embodiments and working principle of this utility model will be further described in detail below with reference to the accompanying drawings.

[0033] like Figure 2 As shown, an LED driver circuit for in-vehicle ambient lighting includes an SBC chip. The SBC chip is provided with an LED constant current terminal group. The LED constant current terminal group is provided with LED constant current ports HV0, HV1 and HV2. Each LED constant current port is connected to an LED constant current driver circuit, and each LED constant current driver circuit is connected to a group of LED lights.

[0034] like Figure 3 As shown, three LED constant current drive circuits are cascaded on the LED constant current port HV0, and each LED constant current drive circuit is connected to a group of LEDs with a green light color.

[0035] like Figure 3As shown, the LED constant current port HV0 is connected to one end of resistor R40, and the other end of resistor R40 is connected to the base of transistor Q31; the collector of transistor Q31 is connected to the base of transistor Q28 via resistor R34, the collector of transistor Q28 is connected to the cathode of LED D1, the anode of LED D1 is connected to the cathode of LED D2, and the anode of LED D2 is connected to the power supply VS; the emitter of transistor Q28 is grounded via resistor R43, and the emitter of transistor Q28 is also connected to the base of transistor Q34, the collector of transistor Q34 is connected to the base of transistor Q28, and the emitter of transistor Q34 is grounded;

[0036] The emitter of the transistor Q31 is connected to the power supply VS, and the base of the transistor Q31 is also connected to the power supply VS via resistor R37.

[0037] like Figure 3 As shown, the LED constant current port HV0 is connected to one end of resistor R41, and the other end of resistor R41 is connected to the base of transistor Q32; the collector of transistor Q32 is connected to the base of transistor Q29 via resistor R35, the collector of transistor Q29 is connected to the cathode of LED D3, the anode of LED D3 is connected to the cathode of LED D4, and the anode of LED D4 is connected to the power supply VS; the emitter of transistor Q29 is grounded via resistor R44, and the emitter of transistor Q29 is also connected to the base of transistor Q35, the collector of transistor Q35 is connected to the base of transistor Q29, and the emitter of transistor Q35 is grounded;

[0038] The emitter of the transistor Q32 is connected to the power supply VS, and the base of the transistor Q32 is also connected to the power supply VS via resistor R38.

[0039] like Figure 3 As shown, the LED constant current port HV0 is connected to one end of resistor R42, and the other end of resistor R42 is connected to the base of transistor Q33; the collector of transistor Q33 is connected to the base of transistor Q30 via resistor R36, the collector of transistor Q30 is connected to the cathode of LED D5, the anode of LED D5 is connected to the cathode of LED D6, and the anode of LED D6 is connected to the power supply VS; the emitter of transistor Q30 is grounded via resistor R45, and the emitter of transistor Q30 is also connected to the base of transistor Q36, the collector of transistor Q36 is connected to the base of transistor Q30, and the emitter of transistor Q36 is grounded;

[0040] The emitter of the transistor Q33 is connected to the power supply VS, and the base of the transistor Q33 is also connected to the power supply VS via resistor R39.

[0041] Transistors Q31, Q32, and Q33 are PNP transistors, while transistors Q28, Q29, Q30, Q34, Q35, and Q36 are NPN transistors. LEDs D1, D2, D3, D4, D5, and D6 are green LEDs; the color can be changed as needed.

[0042] like Figure 4 As shown, three LED constant current drive circuits are cascaded on the LED constant current port HV1, and each LED constant current drive circuit is connected to a group of red LED lights.

[0043] like Figure 4 As shown, the LED constant current port HV1 is connected to one end of resistor R52, and the other end of resistor R52 is connected to the base of transistor Q40; the collector of transistor Q40 is connected to the base of transistor Q37 via resistor R46, the collector of transistor Q37 is connected to the cathode of LED D7, the anode of LED D7 is connected to the cathode of LED D8, and the anode of LED D8 is connected to the power supply VS; the emitter of transistor Q37 is grounded via resistor R55, and the emitter of transistor Q37 is also connected to the base of transistor Q43, the collector of transistor Q43 is connected to the base of transistor Q37, and the emitter of transistor Q43 is grounded;

[0044] The emitter of the transistor Q40 is connected to the power supply VS, and the base of the transistor Q40 is also connected to the power supply VS via resistor R49.

[0045] like Figure 4 As shown, the LED constant current port HV1 is connected to one end of resistor R53, and the other end of resistor R53 is connected to the base of transistor Q41; the collector of transistor Q41 is connected to the base of transistor Q38 via resistor R47, the collector of transistor Q38 is connected to the cathode of LED D9, the anode of LED D9 is connected to the cathode of LED D10, and the anode of LED D10 is connected to the power supply VS; the emitter of transistor Q38 is grounded via resistor R56, and the emitter of transistor Q38 is also connected to the base of transistor Q44, the collector of transistor Q44 is connected to the base of transistor Q38, and the emitter of transistor Q44 is grounded;

[0046] The emitter of the transistor Q41 is connected to the power supply VS, and the base of the transistor Q41 is also connected to the power supply VS via resistor R50.

[0047] like Figure 4 As shown, the LED constant current port HV1 is connected to one end of resistor R54, and the other end of resistor R54 is connected to the base of transistor Q42; the collector of transistor Q42 is connected to the base of transistor Q39 via resistor R48, the collector of transistor Q39 is connected to the cathode of LED D11, the anode of LED D11 is connected to the cathode of LED D12, and the anode of LED D12 is connected to the power supply VS; the emitter of transistor Q39 is grounded via resistor R57, and the emitter of transistor Q39 is also connected to the base of transistor Q45, the collector of transistor Q45 is connected to the base of transistor Q39, and the emitter of transistor Q45 is grounded;

[0048] The emitter of the transistor Q42 is connected to the power supply VS, and the base of the transistor Q42 is also connected to the power supply VS via resistor R51.

[0049] Transistors Q40, Q41, and Q42 are PNP transistors, while transistors Q37, Q38, Q39, Q43, Q44, and Q45 are NPN transistors. LEDs D7, D8, D9, D10, D11, and D12 are red LEDs; the color can be changed as needed.

[0050] like Figure 5 As shown, three LED constant current drive circuits are cascaded on the LED constant current port HV2, and each LED constant current drive circuit is connected to a group of blue LED lights.

[0051] like Figure 5 As shown, the LED constant current port HV2 is connected to one end of resistor R64, and the other end of resistor R64 is connected to the base of transistor Q49; the collector of transistor Q49 is connected to the base of transistor Q46 via resistor R58, the collector of transistor Q46 is connected to the cathode of LED D13, the anode of LED D13 is connected to the cathode of LED D14, and the anode of LED D14 is connected to the power supply VS; the emitter of transistor Q46 is grounded via resistor R67, and the emitter of transistor Q46 is also connected to the base of transistor Q52, the collector of transistor Q52 is connected to the base of transistor Q46, and the emitter of transistor Q52 is grounded;

[0052] The emitter of the transistor Q49 is connected to the power supply VS, and the base of the transistor Q49 is also connected to the power supply VS via resistor R61.

[0053] like Figure 5As shown, the LED constant current port HV2 is connected to one end of resistor R65, and the other end of resistor R65 is connected to the base of transistor Q50; the collector of transistor Q50 is connected to the base of transistor Q47 via resistor R59, the collector of transistor Q47 is connected to the cathode of LED D15, the anode of LED D15 is connected to the cathode of LED D16, and the anode of LED D16 is connected to the power supply VS; the emitter of transistor Q47 is grounded via resistor R68, and the emitter of transistor Q47 is also connected to the base of transistor Q53, the collector of transistor Q53 is connected to the base of transistor Q47, and the emitter of transistor Q53 is grounded;

[0054] The emitter of the transistor Q50 is connected to the power supply VS, and the base of the transistor Q50 is also connected to the power supply VS via resistor R62.

[0055] like Figure 5 As shown, the LED constant current port HV2 is connected to one end of resistor R66, and the other end of resistor R66 is connected to the base of transistor Q51; the collector of transistor Q51 is connected to the base of transistor Q48 via resistor R60, the collector of transistor Q48 is connected to the cathode of LED D17, the anode of LED D17 is connected to the cathode of LED D18, and the anode of LED D18 is connected to the power supply VS; the emitter of transistor Q48 is grounded via resistor R69, and the emitter of transistor Q48 is also connected to the base of transistor Q54, the collector of transistor Q54 is connected to the base of transistor Q48, and the emitter of transistor Q54 is grounded;

[0056] The emitter of the transistor Q51 is connected to the power supply VS, and the base of the transistor Q51 is also connected to the power supply VS via resistor R63.

[0057] Transistors Q49, Q50, and Q51 are PNP transistors, while transistors Q46, Q47, Q48, Q52, Q53, and Q54 are NPN transistors. LEDs D13, D14, D15, D16, D17, and D18 are blue LEDs, and the color can be changed as needed.

[0058] The power supply terminal VS of the SBC chip is connected to the power supply VS, and the ground terminal GND of the SBC chip is grounded.

Claims

1. An LED driver circuit for vehicle interior ambient lighting, characterized in that, It includes an SBC chip, which is equipped with an LED constant current terminal group. The LED constant current terminal group is connected to at least one LED constant current driving circuit, and each LED constant current driving circuit is connected to a group of LED lights.

2. The LED driving circuit for vehicle interior ambient lighting according to claim 1, characterized in that, The LED constant current drive circuit includes a transistor Q31, which is a PNP transistor. The base of transistor Q31 is connected to the LED constant current terminal group via resistor R40. The base of transistor Q31 is also connected to the power supply VS via resistor R37. The emitter of transistor Q31 is connected to the power supply VS. The collector of transistor Q31 is connected to the base of transistor Q28 via resistor R34. Transistor Q28 is an NPN transistor. The collector of transistor Q28 is connected to the LED lamp group. The emitter of transistor Q28 is grounded via resistor R43. The emitter of transistor Q28 is also connected to the base of transistor Q34, which is an NPN transistor. The collector of transistor Q34 is connected to the base of transistor Q28. The emitter of transistor Q34 is grounded.

3. The LED driving circuit for vehicle interior ambient lighting according to claim 2, characterized in that, The LED light group contains two light-emitting diodes. The negative terminal of one light-emitting diode is connected to the collector of the transistor Q28, the positive terminal of one light-emitting diode is connected to the negative terminal of the other light-emitting diode, and the positive terminal of the other light-emitting diode is connected to the power supply VS.

4. The LED driving circuit for vehicle interior ambient lighting according to claim 3, characterized in that, The LED constant current terminal group is provided with LED constant current port HV0, LED constant current port HV1 and LED constant current port HV2; Among them, the LED constant current port HV0 is connected to the LED lamp group with green light color through the LED constant current driving circuit; LED constant current port HV1 is connected to the LED group with red light emission color via the LED constant current drive circuit; The LED constant current port HV2 is connected to the blue LED group via the LED constant current drive circuit.

5. The LED driving circuit for vehicle interior ambient lighting according to claim 4, characterized in that, The LED constant current port HV0, LED constant current port HV1 and LED constant current port HV2 are each connected to at least one LED constant current driving circuit.

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