Front interior light circuit

Abstract

This utility model relates to the field of vehicle interior lighting technology, and in particular to a front interior lighting circuit, which includes a front protection module, an MCU control module, multiple function button modules, a drive module composed of multiple LED drive circuits, and multiple LED lighting units. The input terminal of the front protection module is connected to the positive terminal of the vehicle body power supply, and the output terminal is connected to the power input terminals of the MCU control module and the drive module respectively. The MCU control module includes an MCU chip, a 5V power supply unit, a LIN communication unit, and a data storage unit. One end of each of the multiple function button modules is grounded, and the other end is connected to the GPIO input pin of the MCU chip respectively. The input terminal of each drive circuit is connected to the PWM output pin of the MCU chip, and the output terminal is connected to the positive terminal of the corresponding LED load respectively. The negative terminal of each of the multiple LED lighting units is grounded, and the positive terminal is connected to the output terminal of the corresponding drive circuit respectively. It can automatically recognize the door opening signal command. The lights are controlled by LIN, and will report faults in a timely manner. It can also realize the brightness adjustment of the lights.

Description

Technical Field

[0001] This utility model relates to the field of vehicle interior lighting technology, and in particular to a front interior lighting circuit. Background Technology

[0002] In existing technologies, automotive front interior lighting systems typically employ hard-wired control circuits. Their basic components include a power supply unit, a mechanical control switch, and a light source module (which can be an incandescent bulb or LED). The control logic of this system is a simple binary switch: when the control switch is closed, the light source module is powered on and illuminates; when the control switch is open, the light source module is de-energized and extinguishes. This traditional architecture has significant technical limitations.

[0003] Firstly, the system only supports on / off control of lights and cannot achieve advanced functions such as brightness adjustment;

[0004] Secondly, the system lacks a fault monitoring mechanism. When components such as LEDs fail due to open circuits, the system does not have the ability to self-diagnose faults or report status, making it difficult to provide timely warnings to the driver about abnormal lighting conditions.

[0005] Therefore, this one-way open-loop control mode significantly restricts the reliability and functionality of the lighting system. Utility Model Content

[0006] The technical problem to be solved by this utility model is: in order to solve the problem that the existing technology in the background art has the problem of using simple switch control, only supporting two states of on / off, unable to adjust the brightness, and lacking fault detection function, and unable to automatically alarm when abnormalities such as LED open circuit occur, a front indoor light circuit is provided.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a front indoor light circuit, comprising:

[0008] The front-end protection module has its input terminal connected to the positive terminal of the vehicle body power supply, and its output terminal connected to the power input terminal of the MCU control module and the power input terminal of the drive module, respectively.

[0009] The MCU control module includes an MCU chip, a 5V power supply unit, a LIN communication unit, and a data storage unit. The input terminal of the 5V power supply unit is connected to the output terminal of the front-end protection module, and its output terminal is connected to the power supply pin of the MCU chip. The LIN signal line of the LIN communication unit is connected to the vehicle body LIN bus, and its data line is connected to the communication pin of the MCU chip. The data storage unit is connected to the MCU chip via an I²C or SPI bus.

[0010] Multiple function button modules, with one end of each button module grounded and the other end connected to the GPIO input pin of the MCU chip;

[0011] A driving module composed of multiple LED driving circuits, with the input terminal of each driving circuit connected to the PWM output pin of the MCU chip and the output terminal connected to the positive terminal of the corresponding LED load.

[0012] Multiple LED lighting units are provided, with the negative terminal of each LED lighting unit grounded and the positive terminal connected to the output terminal of the corresponding driving circuit.

[0013] According to one embodiment of the present invention, the plurality of function keys include:

[0014] The door control indicator button module includes a door control indicator button SD1. Pin 2 of the door control indicator button SD1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistors DR3 and DR8, Zener diode DD3 and voltage divider resistor DF7, and then connected to pin 46 PC10 of the MCU chip.

[0015] The front interior light button module includes a front interior light button SF1. Pin 2 of the front interior light button SF1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistors FR1, FR3, Zener diode FD1, and FR2, and then to pin 47, PC11 of the MCU chip.

[0016] The left reading light button module includes a left reading light button SL1. Pin 2 of the left reading light button SL1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistors LR1, LR3, Zener diode LD1, and LR2, and then to pin 45, PC9 of the MCU chip.

[0017] The right reading light button module includes a right reading light button SR1. Pin 2 of the right reading light button SR1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistor RR1, voltage divider resistor RR5, Zener diode RD4, and voltage divider resistor RR4, and then connected to pin 44 PG7 of the MCU chip.

[0018] The backlight button module includes a backlight button SB1. Pin 2 of the backlight button SB1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistors BR1, BR3, Zener diode RD1, and BR2, and then to pin 43 PG6 of the MCU chip.

[0019] According to one embodiment of the present invention, a plurality of LED driving circuits include:

[0020] The reading light driver circuit includes a left reading light driver circuit and a right reading light driver circuit. The output of the left reading light driver circuit is connected to pin 1 (PH8) of the MCU chip, and the output of the right reading light driver circuit is connected to pin 7 (PH6) of the MCU chip. The input of the reading light driver circuit is connected to the first front-end protection circuit.

[0021] The output of the door-controlled light driver circuit is connected to pin PB0 of the MCU chip (pin 26).

[0022] Indoor light driving circuit and key backlight driving circuit.

[0023] According to one embodiment of the present invention, the first front-end protection circuit includes a filter capacitor RC1, a filter capacitor RC5, a common-mode suppression inductor RL3, a resistor R9, a capacitor RC4, a transient voltage suppression diode RT1, a capacitor RC14, a capacitor RC2, a capacitor RC3, a reverse connection protection diode RD3, and a capacitor RC13. The filter capacitors RC1 and RC5 are connected in parallel, with one end connected to the positive terminal network of the vehicle power supply and the other end grounded. The common-mode suppression inductor RL3 includes a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal is connected to the positive terminal network of the vehicle power supply, and the second and third terminals are grounded. One end of the resistor R9 is connected to the first terminal, and the other end is connected to the fourth terminal. One end of the capacitors RC4, RT1, RC14, RC2, and RC3 is connected to the fourth terminal, and the other ends are all grounded. The positive terminal of the reverse connection protection diode RD3 is connected to the fourth terminal, and its negative terminal is connected to one end of the capacitor RC13 and connected to the input terminals of the left reading light drive circuit and the right reading light drive circuit. The other end of the capacitor RC13 is grounded.

[0024] The left reading light driver circuit includes resistor R4, transistor RQ3, reference diode RD2, capacitor RC7, filter capacitor C1, first left reading LED RL1, second left reading LED RL2, absorption capacitor LC1, absorption capacitor LC2, resistor R5, NMOS transistor RQ1, resistor R8, capacitor RC11, and resistor R7.

[0025] The base of transistor RQ3 is connected to one end of filter capacitor C1, reference diode RD2, and resistor R4. The other end of filter capacitor C1 and reference diode RD2 is grounded. The other end of resistor R4 is connected to the output of the first front-end protection circuit. Capacitor RC7 is connected in parallel with reference diode RD2. The drain of NMOS transistor RQ1 is connected to one end of resistor R5. The other end of resistor R5 is connected to the emitter of transistor RQ3. The source of NMOS transistor RQ1 is grounded. The gate of NMOS transistor RQ1 is connected to one end of resistor R8, capacitor RC11, and resistor R7. The other end of resistor R8 and capacitor RC11 is grounded. The other end of resistor R7 is connected to pin PH8 of the MCU chip.

[0026] The collector of transistor RQ3 is connected from bottom to top to resistor R12, first left reading LED RL1, and second left reading LED RL2, and then to the output of the first front-end protection circuit. The first left reading LED RL1 and the second left reading LED RL2 are connected in parallel to absorption capacitor LC1 and absorption capacitor LC2, respectively.

[0027] The right reading light driving circuit includes resistor R2, transistor RQ4, reference diode RD1, filter capacitor RC12, capacitor RC5, first right reading LED RR2, second right reading LED RR3, absorption capacitor RC9, absorption capacitor RC8, resistor R14, resistor R13, resistor R1, NMOS transistor RQ2, resistor R3, capacitor RC10, and resistor R6.

[0028] The base of transistor RQ4 is connected to one end of filter capacitor RC12, reference diode RD1, and resistor R2. The other end of filter capacitor RC12 and reference diode RD1 is grounded. The other end of resistor R2 is connected to the output of the first front-end protection circuit. Capacitor RC5 is connected in parallel with reference diode RD1. The drain of NMOS transistor RQ2 is connected to one end of resistor R1. The other end of resistor R1 is connected to the emitter of transistor RQ4. The source of NMOS transistor RQ2 is grounded. The gate of NMOS transistor RQ2 is connected to one end of resistor R3, capacitor RC10, and resistor R6. The other end of resistor R3 and capacitor RC10 is grounded. The other end of resistor R6 is connected to pin 7 PH6 of the MCU chip.

[0029] The collector of transistor RQ3 is connected from bottom to top to resistor R14, second right reading LED RR3, and first right reading LED RR2, and then to the output of the first front-end protection circuit. The first right reading LED RR2, the second right reading LED RR3, and resistor R14 are connected in parallel to absorption capacitors RC9, RC8, and resistor R13, respectively.

[0030] According to one embodiment of the present invention, the input terminal of the door control light driving circuit is connected to the door control signal detection circuit. The door control signal detection circuit includes a transient voltage suppression diode DT1, a diode DD2, a resistor DR1, and a resistor DR2. One end of the resistor DR1 is connected to a 5V voltage, and the other end is connected between the diode DD2 and the resistor DR2. The other end of the resistor DR2 is connected to pin 6 PH5 of the MCU chip. The other end of the diode DD2 is connected to one end of the transient voltage suppression diode DT1 and is connected to the input terminal of the door control light driving circuit. The other end of the transient voltage suppression diode DT1 is grounded.

[0031] The gate-controlled light driver circuit includes an NMOS transistor DQ1, resistors DR4 and RD5, a gate-controlled LED DL1, and a capacitor DC2. The gate-controlled LED DL1 and capacitor DC2 are connected in parallel, with one end connected to the output of the gate signal detection circuit and the other end connected to one end of resistor DR5. The other end of resistor DR5 is connected to the drain (D) terminal of NMOS transistor DQ1. The gate (G) terminal of NMOS transistor DQ1 is connected to pin 26 PB0 of the MCU chip through resistor DR4.

[0032] According to one embodiment of the present invention, the input terminal of the indoor lamp driving circuit is connected to a second front-end protection circuit. The second front-end protection circuit includes a transient suppression diode IT1, a capacitor IC1, a capacitor IC2, and a reverse protection diode ID1. One end of the transient suppression diode IT1, capacitor IC1, and capacitor IC2 is connected to the positive terminal network of the vehicle body power supply, and the other end is grounded. The positive terminal of diode ID1 is connected to the positive terminal of the vehicle body power supply, and its negative terminal is connected to the input terminal of the indoor lamp driving circuit.

[0033] The indoor light driver circuit includes transistor IQ1, filter capacitor IC3, resistor IR7, base bias diode ID2, filter capacitor IC4, resistor IR1, resistor IR6, first indoor LED IL1, second indoor LED IL2, third indoor LED IL3, fourth indoor LED IL4, capacitor IC5, capacitor IC6, capacitor IC7, capacitor IC8, Zener diode ID3, Zener diode ID4, current limiting resistor IR2, current limiting resistor IR3, current limiting resistor IR4, and current limiting resistor IR5.

[0034] The base of transistor IQ1 is connected to one end of filter capacitor IC3 and resistor IR7. The other end of filter capacitor IC3 is grounded. The other end of resistor IR7 is connected to resistor IR1 and one end of base bias diode ID2. The other end of resistor IR1 is connected to the output terminal of the second front-end protection circuit. The other end of base bias diode ID2 is grounded. Filter capacitor IC4 is connected in parallel across the two ends of bias diode ID2.

[0035] The first indoor LED light IL1 and the second indoor LED light IL2 are connected in series, with capacitors IC5 and IC6 connected in parallel between them respectively. The third indoor LED light IL3 and the fourth indoor LED light IL4 are connected in series, with capacitors IC7 and IC8 connected in parallel between them respectively. The input terminals of the third indoor LED light IL3 and the first indoor LED light IL1 are connected to the output terminal of the second front-end protection circuit. The output terminals of the second indoor LED light IL2 and the fourth indoor LED light IL4 are connected to each other.

[0036] One end of current-limiting resistors IR2 and IR3 is connected to the output terminal of Zener diode ID3, and the other end is connected to the collector of transistor IQ1. The input terminal of Zener diode ID3 is connected to the output terminals of the second indoor LED IL2 and the fourth indoor LED IL4. One end of current-limiting resistors IR3 and IR4 is connected to the output terminal of Zener diode ID4, and the other end is connected to the collector of transistor IQ1. The input terminal of Zener diode ID4 is connected to the output terminals of the second indoor LED IL2 and the fourth indoor LED IL4.

[0037] According to one embodiment of the present invention, the input terminal of the button backlight driving circuit is connected to a third front-end protection circuit. The third front-end protection circuit includes a diode BT1, a capacitor BC3, a first resistor BR6, and a diode BD2. The diode BT1, capacitor BC3, and first resistor BR6 are connected in parallel, with one end connected to the backlight power input network and the other end grounded. The positive terminal of the diode BD2 is connected to the backlight power input network, and the other end is connected to the button backlight driving circuit.

[0038] The button backlight driving circuit includes a second backlight LED BC2, a first backlight LED BC1, capacitors BC2 and BC1, a second resistor BR4, a third resistor BR5, and a fourth resistor BR7. One end of the second backlight LED BL2 is connected to the output terminal of the third front-end protection circuit, and the other end is connected to one end of the first backlight LED BL1. Capacitors BC2 and BC1 are connected in parallel to the second backlight LED BL2 and the first backlight LED BL1, respectively. The second resistor BR4, the third resistor BR5, and the fourth resistor BR7 are connected in parallel, with one end connected to the other end of the first backlight LED BL1, and the other ends are all grounded.

[0039] According to one embodiment of the present invention, the 5V power supply unit includes chip U1, capacitors UC3, UC2, UC1, UC32, chip U3, capacitors UC21, UC31, UC22, UC4, Zener diode UD1, and resistor UR19.

[0040] Pin 8 of chip U1 is connected to the positive terminal of the vehicle power supply. One end of capacitors UC1 and UC32 is connected to pin 8 of chip U1, and the other end is grounded. Pin 1 of chip U1 is connected to 5V voltage. One end of capacitors UC3 and UC2 is connected to pin 1 of chip U1, and the other end is grounded.

[0041] Pin 1 of chip U3 is connected to the positive network of the vehicle's power supply. One end of capacitor UC21 is connected to pin 1 of chip U3, and the other end is connected to pin 2 of chip U3. Pin 2 of chip U3 is grounded. Pin 3 of chip U3 is connected to a 3.3V voltage. One end of capacitors UC31, UC22, and UC4 is connected to pin 3 of chip U1. The other ends of capacitors UC31 and UC22 are connected to pin 4 of chip U3. Pin 2 of chip U3 is grounded, and the other end of capacitor UC4 is grounded. The negative terminal of Zener diode UD1 is connected to pin 3 of chip U1, and its positive terminal is connected to one end of resistor UR19. The other end of resistor UR19 is grounded.

[0042] According to one embodiment of this utility model, pin 1 of the MCU chip is connected to one end of resistor UR2, and the other end of resistor UR2 is connected to one end of capacitor UC23 and resistor UR27, respectively. The other end of capacitor UC23 is grounded, and the other end of resistor UR27 is connected to the L_READ_CON network. Pin 3 of the MCU chip is connected to one end of resistor UR29, and the other end of resistor UR29 is connected to the CO_IN network. Pin 4 of the MCU chip is connected to one end of resistor UR30, and the other end of resistor UR30 is connected to the CO_OUT network. Pin 5 of the MCU chip is connected to the RST network. Pin 6 of the MCU chip is connected to one end of resistor UR5, and the other end of resistor UR5 is connected to the DOOR_IN_SIG network. Pin 7 of the MCU chip is connected to one end of resistor UR4, and the other end of resistor UR4 is connected to capacitor UC26 and resistor UR28, respectively. One end of capacitor UC26 is grounded, and the other end of resistor UR28 is connected to the R_READ_CON network. Pin 10 of the MCU chip is connected to one end of capacitors UC9, UC8, and UC7 and grounded. Pin 11 of the MCU chip is connected to the other end of capacitors UC9, UC8, and UC7 and connected to 3.3V. Pin 13 of the MCU chip is connected to one end of capacitors UC12, UC11, and UC10 and grounded. Pin 14 of the MCU chip is connected to the other end of capacitors UC12, UC11, and UC10 and connected to 3.3V.With a 3V voltage, pin 15 of the MCU chip is connected to one end of capacitor UC30, and the other end of capacitor UC30 is grounded. Pin 16 of the MCU chip is connected to one end of capacitor UC13, and the other end of capacitor UC13 is grounded. Pin 17 of the MCU chip is connected to one end of capacitor UC29 and resistor UR6, and the other end of capacitor UC29 is grounded. The other end of resistor UR6 is connected to one end of capacitor UC19, and the other end of capacitor UC19 is grounded. Pin 18 of the MCU chip is connected to one end of capacitor UC28 and resistor UR7, and the other end of capacitor UC28 is grounded. The other end of resistor UR7 is connected to one end of capacitor UC20, and the other end of capacitor UC20 is grounded. Pin 19 of the MCU chip is connected to resistor UR22 and capacitor UC33 in sequence and then grounded. Pin 22 of the MCU chip is connected to resistor UR23 and capacitor UC34 in sequence and then grounded. Pin 23 of the MCU chip is connected to resistor UR24 and capacitor UC35 in sequence and then grounded. Pin 25 of the MCU chip is connected to one end of capacitors UC14 and UC15. The other end is grounded. Pin 26 of the MCU chip is connected to one end of resistor UR9. The other end of resistor UR9 is connected to capacitor UC27 and the DOOR_LED_CON network. Pin 30 of the MCU chip is connected to one end of resistor UR11. The other end of resistor UR11 is connected to one end of resistor UR13 and the ER_SCL network. The other end of resistor UR13 is connected to 3.3V. Pin 31 of the MCU chip is connected to one end of resistor UR10. The other end of resistor UR10 is connected to one end of resistor UR12 and the ER_SDA network. The other end of resistor UR12 is connected to 3.3V. Pin 34 of the MCU chip is connected to the Sf network. Pin 37 of the MCU chip is connected to one end of resistors UR20 and UR21. The other end of resistor UR20 is connected to 5V. The other end of UR21 is grounded. Pin 39 of the MCU chip is connected to the DATA network. Pin 40 of the MCU chip is connected to the CLOCK network. Pin 43 of the MCU chip is connected to the Backlight_KD network. Pin 44 of the MCU chip is connected to the Right network. The MCU chip's pin 45 is connected to the Left reading light KD network, pin 46 is connected to the Door control indicator KD network, and pin 47 is connected to the Front interior light KD network.

[0043] According to one embodiment of the present invention, a feedback detection circuit is further included. The feedback detection circuit includes a resistor SR5, a transient voltage suppression diode ST1, a capacitor SC2, a resistor SR4, an NMOS transistor SQ1, a resistor SR3, a capacitor SC1, and a resistor SR2. One end of the resistor SR5 is connected to the positive terminal network of the vehicle body power supply, and the other end is connected to the status feedback signal line. One end of the transient voltage suppression diode ST1 and the capacitor SC2 are connected to the status feedback signal line, and the other end is grounded. One end of the resistor SR4 is connected to the status feedback signal line, and the other end is connected to the drain (D) terminal of the NMOS transistor SQ1. The source (S) terminal of the NMOS transistor SQ1 is grounded. One end of the resistor SR3, the capacitor SC1, and the resistor SR2 are connected to the gate (G) terminal of the NMOS transistor SQ1, and the other end of the resistor SR3 and the capacitor SC1 is grounded. The other end of the resistor SR2 is connected to the Sf network.

[0044] The beneficial effects of this utility model are:

[0045] (1) Based on the basic indoor lighting function, the door control indicator, button backlight and left and right reading light modules are innovatively integrated to form a complete vehicle interior lighting system. Through modular circuit design, independent control and collaborative operation of each lighting area are realized.

[0046] (2) The system adopts a LIN bus communication architecture and establishes a master-slave control network. The system uses a microcontroller to achieve precise real-time control of each lighting unit, supports multi-level brightness adjustment and scene-based lighting mode switching, and significantly improves the user experience.

[0047] (3) An innovative dual-channel feedback system with LIN bus communication and hard-wired direct connection was designed. This system can monitor the working status of each lighting unit in real time, detect and report abnormal situations in a timely manner, and greatly improve the reliability of the system.

[0048] (4) The circuit design adopts a multi-level protection scheme, including three levels: input protection, drive protection and load protection, which effectively prevents various electrical fault risks and ensures stable system operation;

[0049] (5) The system supports a variety of preset lighting scenes and can be customized according to user needs, realizing a functional leap from basic lighting to intelligent lighting. Attached Figure Description

[0050] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0051] Figure 1 This is a schematic diagram of the structure of this utility model.

[0052] Figure 2 This is a circuit diagram of the reading lamp driving circuit in this utility model.

[0053] Figure 3 This is a circuit diagram of the indoor lamp driving circuit in this utility model.

[0054] Figure 4 This is a circuit diagram of the button backlight driving circuit in this utility model.

[0055] Figure 5 This is the circuit diagram of the door-controlled light drive circuit in this utility model.

[0056] Figure 6 This is a circuit diagram of the gate control signal detection circuit in this utility model.

[0057] Figure 7 This is a circuit diagram of the multiple function button modules in this utility model.

[0058] Figure 8 This is the circuit diagram of the 5V power supply unit in this utility model.

[0059] Figure 9 This is the circuit diagram of the MCU chip in this utility model.

[0060] Figure 10 This is a circuit diagram of the feedback detection circuit in this utility model.

[0061] In the diagram: 1. Vehicle body; 2. Front-end protection module; 3. MCU chip; 4. 5V power supply unit; 5. LIN communication unit; 6. Data storage unit; 7. Door control indicator button module; 8. Front interior light button module; 9. Left reading light button module; 10. Right reading light button module; 11. Backlight button module; 12. Left reading LED lighting unit; 13. Right reading LED lighting unit; 14. Door control LED lighting unit; 15. Interior LED lighting unit; 16. Button backlight LED lighting unit; 18. Reading light driver circuit; 19. Door control light driver circuit; 20. Interior light driver circuit; 21. Button backlight driver circuit. Detailed Implementation

[0062] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0063] like Figure 1As shown, the front interior lighting circuit includes a front protection module 2, an MCU control module, multiple function button modules, a driver module consisting of multiple LED driver circuits, and multiple LED lighting units. The input terminal of the front protection module 2 is connected to the positive terminal of the vehicle body 1 power supply, and the output terminals are respectively connected to the power input terminals of the MCU control module and the driver module. The MCU control module includes an MCU chip 3, a 5V power supply unit 4, a LIN communication unit 5, and a data storage unit 6. The input terminal of the 5V power supply unit 4 is connected to the output terminal of the front protection module 2, and its output terminal is connected to the power pin of the MCU chip 3. The LIN signal line of the LIN communication unit 5 is connected to the LIN bus of the vehicle body 1, and its data line is connected to the communication pin of the MCU chip 3. The data storage unit 6 is connected to the MCU chip 3 via an I²C or SPI bus. One end of the multiple function button modules is grounded, and the other end is respectively connected to the M... The GPIO input pins of the CU chip 3 include multiple function button modules, specifically door control indicator button module 7, front indoor light button module 8, left reading light button module 9, right reading light button module 10, and backlight button module 11. The driving module consists of multiple LED driving circuits, with the input terminals of each driving circuit connected to the PWM output pins of the MCU chip 3, and the output terminals connected to the positive terminals of the corresponding LED loads. The multiple LED driving circuits include reading light driving circuit 18, door control light driving circuit 19, indoor light driving circuit 20, and button backlight driving circuit 21. The negative terminals of multiple LED lighting units are grounded, and the positive terminals are connected to the output terminals of the corresponding driving circuits, specifically including left reading LED lighting unit 12, right reading LED lighting unit 13, door control LED lighting unit 14, indoor LED lighting unit 15, and button backlight LED lighting unit 16.

[0064] The front-end protection module 2 provides reverse connection protection for the power input terminal of the vehicle body 1 to the drive module. The 5V power supply unit 4 provides power signals to the MCU chip 3, and the LIN communication unit 5 provides processing for the MCU chip 3 and LIN signals. The data storage unit 6 provides more space for the MCU chip 3's logic algorithms. The door control indicator button 7 is for opening the door; the front interior light button 8 controls the on / off state of the interior LED lights; the left reading light button 9 controls the on / off state of the left reading LED lights; the right reading light button 10 controls the on / off state of the right reading LED lights; and the backlight button 11 controls the on / off state of the backlight LED lights. The door control light drive circuit 19 drives the door control LED lighting unit 14; the left reading light drive circuit drives the left reading LED lighting unit 12; and the interior light drive circuit drives the interior LED lighting unit 15. The left reading LED lighting unit 12, the right reading LED lighting unit 13, the door control LED lighting unit 14, the indoor LED lighting unit 15, and the button backlight LED lighting unit 16 are formed by connecting LEDs that meet optical and material requirements through a certain circuit connection method.

[0065] like Figure 2 and Figure 9 As shown, the input terminal of the reading light drive circuit 18 is connected to the first front-end protection circuit. The first front-end protection circuit includes a filter capacitor RC1, a filter capacitor RC5, a common-mode rejection inductor RL3, a resistor R9, a capacitor RC4, a transient voltage suppression diode RT1, a capacitor RC14, a capacitor RC2, a capacitor RC3, a reverse connection protection diode RD3, and a capacitor RC13. Filter capacitors RC1 and RC5 are connected in parallel, with one end connected to the positive network of the vehicle body power supply and the other end grounded. The common-mode rejection inductor RL3 includes a first terminal, a second terminal, a third terminal, and... The fourth terminal is connected to the positive network of the vehicle power supply. The second and third terminals are grounded. One end of resistor R9 is connected to the first terminal, and the other end is connected to the fourth terminal. One end of capacitor RC4, transient voltage suppression diode RT1, capacitor RC14, capacitor RC2, and capacitor RC3 are connected to the fourth terminal, and the other ends are all grounded. The positive terminal of the reverse diode RD3 is connected to the fourth terminal, and its negative terminal is connected to one end of capacitor RC13, which is also connected to the input terminals of the left and right reading light drive circuits. The other end of capacitor RC13 is grounded.

[0066] When power is input, it first passes through filter capacitors RC1 and RC5, and then through common-mode rejection inductor RL3, which effectively suppresses common-mode signal interference noise. Resistor R9, connected in parallel with RL3, regulates the reverse voltage dissipation generated by RL3, thereby reducing the current and heat flowing through the inductor and improving circuit stability and reliability. Transient voltage suppressor diode RT1 acts as a bidirectional voltage stabilizer. When a large surge voltage occurs in the circuit, the diode breaks down, limiting the input voltage and protecting components in subsequent circuits. Capacitors RC14, RC2, and RC3 provide filtering; the reverse protection diode RD3, through its internal PN junction, enables forward current conduction and reverse current cutoff.

[0067] The left reading light driver circuit includes resistor R4, transistor RQ3, reference diode RD2, capacitor RC7, filter capacitor C1, first left reading LED RL1, second left reading LED RL2, absorption capacitor LC1, absorption capacitor LC2, resistor R5, NMOS transistor RQ1, resistor R8, capacitor RC11, and resistor R7. The base of transistor RQ3 is connected to one end of filter capacitor C1, reference diode RD2, and resistor R4. The other end of filter capacitor C1 and reference diode RD2 is grounded. The other end of resistor R4 is connected to the output terminal of the first front-end protection circuit. Capacitor RC7 is connected in parallel with reference diode RD2. The drain of NMOS transistor RQ1 is connected to... One end of resistor R5 is connected to the emitter of transistor RQ3. The source (S) of NMOS transistor RQ1 is grounded. The gate (G) of NMOS transistor RQ1 is connected to one end of resistor R8, capacitor RC11, and resistor R7. The other ends of resistor R8 and capacitor RC11 are grounded. The other end of resistor R7 is connected to pin PH8 of MCU chip 3. The collector of transistor RQ3 is connected from bottom to top to resistor R12, first left reading LED RL1, and second left reading LED RL2, and then connected to the output of the first front-end protection circuit. The first left reading LED RL1 and the second left reading LED RL2 are connected in parallel to absorption capacitors LC1 and LC2, respectively.

[0068] The left reading LED uses a transistor constant current drive scheme. The first left reading LED RL1 and the second left reading LED RL2 are connected in parallel with absorption capacitors LC1 and LC2 respectively, which can absorb surge current. Resistor R12 is connected in series with the first left reading LED RL1 and the second left reading LED RL2, acting as a voltage divider. When the LED starts working immediately after power-on, it buffers the suddenly increased current signal, reducing the impact on other components. Reference diode RD2 provides a reference voltage to transistor RQ3, and filter capacitor C1 is the base-to-ground capacitance of transistor RQ3. When the first left reading LED RL1 or the second left reading LED RL2 is lit, the drain (D) of NMOS transistor RQ1 is high, its source (S) is grounded, the NMOS transistor is turned on, and the gate (G) is high through resistor R7, with the signal L_READ_CON high, connected to pin PH8 on MCU chip 3, thus realizing the corresponding left reading LED control.

[0069] Similarly, the right reading LED also uses a transistor constant current drive scheme. The right reading LED drive circuit includes resistor R2, transistor RQ4, reference diode RD1, filter capacitor RC12, capacitor RC5, first right reading LED RR2, second right reading LED RR3, absorption capacitor RC9, absorption capacitor RC8, resistor R14, resistor R13, resistor R1, NMOS transistor RQ2, resistor R3, capacitor RC10, and resistor R6; the base of transistor RQ4 is connected to one end of filter capacitor RC12, reference diode RD1, and resistor R2, the other end of filter capacitor RC12 and reference diode RD1 is grounded, the other end of resistor R2 is connected to the output of the first front-end protection circuit, and capacitor RC5 is connected in parallel with reference diode RD1; NMOS transistor RQ2... The drain (D) terminal is connected to one end of resistor R1, and the other end of resistor R1 is connected to the emitter of transistor RQ4. The source (S) terminal of NMOS transistor RQ2 is grounded. The gate (G) terminal of NMOS transistor RQ2 is connected to one end of resistor R3, capacitor RC10, and resistor R6. The other ends of resistor R3 and capacitor RC10 are grounded. The other end of resistor R6 is connected to pin 7 (PH6) of MCU chip 3. The collector of transistor RQ3 is connected from bottom to top to resistor R14, the second right reading LED RR3, and the first right reading LED RR2, and then to the output of the first front-end protection circuit. The first right reading LED RR2, the second right reading LED RR3, and resistor R14 are connected in parallel to absorption capacitors RC9 and RC8 and resistor R13, respectively.

[0070] The first right reading LED RR2, the second right reading LED RR3, and resistor R14 are connected in parallel with absorption capacitors RC9 and RC8, respectively. This absorbs high-frequency signal noise and voltage spikes that may occur in the circuit, thus stabilizing the LED voltage. When either the first right reading LED RR2 or the second right reading LED RR3 is lit, the drain (D) of NMOS transistor RQ4 is high, its source (S) is grounded, and the NMOS transistor is turned on. The gate (G) is connected to the signal R_READ_CON through resistor R6, which is high and connected to pin PH6 of MCU chip 3, thereby controlling the corresponding right reading LED.

[0071] like Figure 3 As shown, the input terminal of the indoor light driver circuit 20 is connected to the second front-end protection circuit. The second front-end protection circuit includes a transient suppression diode IT1, a capacitor IC1, a capacitor IC2, and a reverse protection diode ID1. One end of the transient suppression diode IT1, capacitor IC1, and capacitor IC2 is connected to the positive terminal network of the vehicle body power supply, and the other end is grounded. The positive terminal of diode ID1 is connected to the positive terminal of the vehicle body power supply, and its negative terminal is connected to the input terminal of the indoor light driver circuit 20.

[0072] The indoor light driver circuit 20 includes a transistor IQ1, a filter capacitor IC3, a resistor IR7, a base bias diode ID2, a filter capacitor IC4, resistors IR1 and IR6, a first indoor LED IL1, a second indoor LED IL2, a third indoor LED IL3, a fourth indoor LED IL4, capacitors IC5, IC6, IC7, and IC8, Zener diodes ID3 and ID4, current-limiting resistors IR2, IR3, IR4, and IR5. The base of transistor IQ1 is connected to one end of filter capacitor IC3 and resistor IR7. The other end of filter capacitor IC3 is grounded. The other end of resistor IR7 is connected to one end of resistor IR1 and base bias diode ID2. The other end of resistor IR1 is connected to the output terminal of the second front-end protection circuit. The other end of base bias diode ID2 is grounded. Filter capacitor IC4 is connected in parallel across the two ends of bias diode ID2. The first indoor LED IL1 and the second indoor LED IL2 are connected to the first indoor LED IL4. Two indoor LED lights IL2 are connected in series, with capacitors IC5 and IC6 connected in parallel between them. A third indoor LED light IL3 and a fourth indoor LED light IL4 are connected in series, with capacitors IC7 and IC8 connected in parallel between them. The input terminals of the third indoor LED light IL3 and the first indoor LED light IL1 are connected to the output terminal of the second front-end protection circuit. The output terminals of the second indoor LED light IL2 and the fourth indoor LED light IL4 are connected. One end of current-limiting resistors IR2 and IR3 is connected to the output terminal of Zener diode ID3, and the other end is connected to the collector of transistor IQ1. The input terminal of Zener diode ID3 is connected to the output terminals of the second indoor LED light IL2 and the fourth indoor LED light IL4. One end of current-limiting resistors IR3 and IR4 is connected to the output terminal of Zener diode ID4, and the other end is connected to the collector of transistor IQ1. The input terminal of Zener diode ID4 is connected to the output terminals of the second indoor LED light IL2 and the fourth indoor LED light IL4.

[0073] During power input, filter capacitor IC4 filters the base bias diode ID2. To reduce the overall power consumption of transistor IQ1, Zener diodes ID3 and ID4, and current-limiting resistors IR2, IR3, IR4, and IR5 are added to the circuit. Similarly, the indoor LED lights use a transistor constant current drive. This solution is simple and cost-effective.

[0074] like Figure 4As shown, the input terminal of the button backlight driving circuit 21 is connected to the third front-end protection circuit. The third front-end protection circuit includes diode BT1, capacitor BC3, first resistor BR6, and diode BD2. Diode BT1, capacitor BC3, and first resistor BR6 are connected in parallel, with one end connected to the backlight power input network and the other end grounded. The positive terminal of diode BD2 is connected to the backlight power input network, and the other end is connected to the button backlight driving circuit 21. The button backlight driving circuit 21 includes a second backlight LED BC2, a first backlight LED BC1, capacitor BC2, capacitor BC1, a second resistor BR4, a third resistor BR5, and a fourth resistor BR7. One end of the second backlight LED BL2 is connected to the output terminal of the third front-end protection circuit, and the other end is connected to one end of the first backlight LED BL1. Capacitors BC2 and BC1 are connected in parallel to the second backlight LED BL2 and the first backlight LED BL1, respectively. The second resistor BR4, the third resistor BR5, and the fourth resistor BR7 are connected in parallel, with one end connected to the other end of the first backlight LED BL1, and the other ends are all grounded.

[0075] When the backlight is powered by a hardwired circuit, the voltage first passes through diode BT1, then capacitor BC3. Resistor BR6 and capacitor BC3 form an RC parallel circuit, which serves as a decoupling mechanism, eliminating high-frequency interference signals on the power line and stabilizing the voltage in the circuit. The backlight LED is driven using a resistive method; the higher the input voltage, the greater the current flowing through the backlight LED.

[0076] like Figure 5 , Figure 6 , Figure 7 and Figure 9 As shown, the input terminal of the gate control light driver circuit 19 is connected to the gate control signal detection circuit. The gate control signal detection circuit includes transient voltage suppression diode DT1, diode DD2, resistor DR1, and resistor DR2. One end of resistor DR1 is connected to a 5V voltage, and the other end is connected between diode DD2 and resistor DR2. The other end of resistor DR2 is connected to pin 6 PH5 of MCU chip 3. The other end of diode DD2 is connected to one end of transient voltage suppression diode DT1 and is connected to the input terminal of gate control light driver circuit 19. The other end of transient voltage suppression diode DT1 is grounded. The gate control light driver circuit 19 includes NMOS transistor DQ1, resistor DR4, resistor RD5, gate control LED DL1, and capacitor DC2. Gate control LED DL1 and capacitor DC2 are connected in parallel. One end of DL1 is connected to the output terminal of the gate control signal detection circuit, and the other end is connected to one end of resistor DR5. The other end of resistor DR5 is connected to the drain (D) terminal of NMOS transistor DQ1. The gate (G) terminal of NMOS transistor DQ1 is connected to pin 26 PB0 of MCU chip 3 through resistor DR4.

[0077] When the gate control power supply is input, it first passes through transient voltage suppression diode DT1, then through diode DD2, and is pulled up to 5V by resistor DR1. Then, it passes through resistor DR2 to form DOOR_IN_SIG, which is connected to pin 6 (PH5) of chip U2, allowing the chip to detect the gate control signal and the gate being open. Simultaneously, the gate control LED DL1 and capacitor DC2 are connected in parallel, resistor DR5 is the drive resistor, and the gate of NMOS transistor DQ1 forms a DOOR_LED_CON network through resistor DR4, connected to pin 26 (PB0) of chip U2. When the gate is open, the gate control signal DOOR is low; when the gate is closed, the gate control signal DOOR is floating. When the gate control indicator button SD1 is pressed, the gate control indicator lights up, indicating that the gate control is disabled. When the gate is opened or closed, the corresponding indicator lights are powered off and need to be restarted by pressing the button again. When the gate control indicator button SD1 is pressed again, the gate control indicator lights off, indicating that the gate control is enabled. When the gate is opened or closed, the corresponding indicator lights will automatically restart after power failure.

[0078] like Figure 7 As shown, the multiple function button modules include a door control indicator button module 7, a front interior light button module 8, a left reading light button module 9, a right reading light button module 10, and a backlight button module 11. The door control indicator button module 7 includes a door control indicator button SD1. Pin 2 of the door control indicator button SD1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistors DR3, DR8, Zener diode DD3, and DF7, and then connected to pin 46 (PC10) of the MCU chip 3. The front interior light button module 8 includes a front interior light button SF1. Pin 2 of the front interior light button SF1 is connected to a 5V power supply. Pin 1 is connected in sequence to voltage divider resistors FR1, FR3, Zener diode FD1, and FR2, and then connected to pin 47 (PC11) of the MCU chip 3. The left reading light button module 9 includes a left reading light button 10, a right reading light button 11, and a backlight button module 11. The left reading light button SL1 has its pin 2 connected to a 5V power supply. Its pin 1 is connected in sequence to voltage divider resistors LR1, LR3, LD1, and LR2, and then to pin 45 (PC9) of MCU chip 3. The right reading light button module 10 includes a right reading light button SR1, whose pin 2 is connected to a 5V power supply. Its pin 1 is connected in sequence to voltage divider resistors RR1, RR5, RD4, and RR4, and then to pin 44 (PG7) of MCU chip 3. The backlight button module 11 includes a backlight button SB1, whose pin 2 is connected to a 5V power supply. Its pin 1 is connected in sequence to voltage divider resistors BR1 and BR3, RD1 and BR2, and then to pin 43 (PG6) of MCU chip 3.

[0079] Resistors FR2, DR7, LR2, RR4, and BR2 are 0Ω resistors and can be used as jumpers if needed. Correspondingly, the front interior light button detection forms a Front interior light _KD network, connected to pin 47 (PC11) of MCU chip 3; the door control indicator button detection forms a Door control indicator _KD network, connected to pin 46 (PC10) of MCU chip 3; the left reading light button detection forms a Left reading light _KD network, connected to pin 45 (PC9) of MCU chip 3; the right reading light button detection forms a Right reading light _KD network, connected to pin 44 (PG7) of MCU chip 3; and the backlight button detection forms a Backlight _KD network, connected to pin 43 (PG6) of MCU chip 3. The button switches are normally in the open state. When a button is pressed, the switch closes, executing the relevant lighting function detection signals; when the button is pressed again, the switch opens, and the lighting function disappears.

[0080] like Figure 8 As shown, the 5V power supply unit includes chip U1, capacitors UC3, UC2, UC1, UC32, chip U3, capacitors UC21, UC31, UC22, UC4, Zener diode UD1, and resistor UR19. Pin 8 of chip U1 is connected to the positive terminal of the vehicle body power supply. One end of capacitors UC1 and UC32 is connected to pin 8 of chip U1, and the other end is grounded. Pin 1 of chip U1 is connected to a 5V voltage. One end of capacitors UC3 and UC2 is connected to pin 1 of chip U1, and the other end is grounded. Pin 1 of chip U3 is connected to the positive network of the vehicle body power supply. Connect one end of capacitor UC21 to pin 1 of chip U3 and the other end to pin 2 of chip U3. Pin 2 of chip U3 is grounded. Pin 3 of chip U3 is connected to a 3.3V voltage. Connect one end of capacitors UC31, UC22 and UC4 to pin 3 of chip U1. Connect the other ends of capacitors UC31 and UC22 to pin 4 of chip U3. Pin 2 of chip U3 is grounded. The other end of capacitor UC4 is grounded. Connect the negative terminal of Zener diode UD1 to pin 3 of chip U1. Connect its positive terminal to one end of resistor UR19. The other end of resistor UR19 is grounded.

[0081] Chips U1 and U3 are voltage conversion chips that convert the input voltage into the appropriate voltage value required by subsequent circuits. Capacitors UC32 and UC1 are input processing capacitors for chip U1, smoothing the POWER signal. Capacitors UC2 and UC3 are output capacitors. Chip U1 converts the input POWER voltage to 5V, which can be used as a pull-up power signal for subsequent circuits. Capacitor UC21 is the input capacitor for chip U3, while capacitors UC31, UC22, and UC4 are the output capacitors for chip U3. Capacitor UC4 is a reserved capacitor to prevent open circuits in either capacitor UC31 or UC22. Chip U3 converts the input POWER voltage to 3.3V to power MCU chip 3. Zener diode UD1 can stabilize the output voltage of chip U3 at 3.3V. Resistor UR19 acts as a current-limiting resistor for Zener diode UD1. When the circuit is working, it can limit the current flowing through Zener diode UD1, avoiding transient high voltage and instantaneous high current, so that the voltage regulation circuit can work stably.

[0082] like Figure 9As shown, pin 1 of MCU chip 3 (represented by U2 in the figure) is connected to one end of resistor UR2. The other end of resistor UR2 is connected to one end of capacitor UC23 and one end of resistor UR27, respectively. The other end of capacitor UC23 is grounded, and the other end of resistor UR27 is connected to the L_READ_CON network. The brightness adjustment of the left reading light is achieved through the LIN signal from vehicle body 1 and the internal registers and memory of MCU chip 3. UR27 is a thermistor. When the temperature of resistor UR27 detected by this pin exceeds the limit temperature of the left reading light, the thermal protection function is activated, turning off the light. Pin 3 of MCU chip 3 is connected to one end of resistor UR29. The other end of resistor UR29 is connected to the CO_IN network. Pin 4 of MCU chip 3 is connected to one end of resistor UR30. The other end of resistor UR30 is connected to the CO_OUT network. The CO_IN and CO_OUT networks are connected to the crystal oscillator output port. With an external crystal oscillator, its stable oscillation frequency can provide a reference clock signal to MCU chip 3, ensuring the consistency of command execution and data processing when receiving instructions from vehicle body 1. Pin 5 of MCU chip 3 is connected to the RST network, which is one of the test points used for repeated software programming of the chip. This network is also pulled up to 3.3V through resistor UR1, and capacitor UC6 is grounded. Pin 6 of MCU chip 3 is connected to one end of resistor UR5, and the other end of resistor UR5 is connected to the DOOR_IN_SIG network for detecting gating signal input. Pin 7 of MCU chip 3 is connected to one end of resistor UR4, and the other end of resistor UR4 is connected to one end of capacitor UC26 and resistor UR28 respectively. The other end of capacitor UC26 is grounded, and the other end of resistor UR28 is connected to the R_READ_CON network. This allows for the configuration of functions such as brightness adjustment of the right reading light through the LIN signal of vehicle body 1 and the internal registers and memory of MCU chip 3. UR28 is a thermistor; when the temperature of resistor UR28 detected by this pin exceeds the limit temperature of the right reading light, the thermal protection function is activated, turning off the light. Pin 10 of MCU chip 3 is connected to one end of capacitors UC9, UC8, and UC7 and grounded. Pin 11 of MCU chip 3 is connected to the other end of capacitors UC9, UC8, and UC7 and connected to a 3.3V voltage. Pin 13 of MCU chip 3 is connected to one end of capacitors UC12, UC11, and UC10 and grounded. Pin 14 of MCU chip 3 is connected to the other end of capacitors UC12, UC11, and UC10 and connected to a 3.3V voltage. Pins 14 and 13 of MCU chip 3 are set as power supply input pins, and the 3.3V output of chip U3 supplies power to MCU chip 3.Pin 15 of MCU chip 3 is connected to one end of capacitor UC30, and the other end of capacitor UC30 is grounded. Pin 16 of MCU chip 3 is connected to one end of capacitor UC13, and the other end of capacitor UC13 is grounded. Pin 17 of MCU chip 3 is connected to one end of capacitor UC29 and resistor UR6, and the other end of capacitor UC29 is grounded. The other end of resistor UR6 is connected to one end of capacitor UC19, and the other end of capacitor UC19 is grounded. Resistor UR6, capacitor UC29, and capacitor UC19 form a π-type filter. Capacitors UC29 and UC19 are used to absorb high-frequency signals, which can better filter out signals in the preset frequency range and eliminate noise and interference signals. Pin 18 of MCU chip 3 is connected to one end of capacitor UC28 and resistor UR7. The other end of capacitor UC28 is grounded. The other end of resistor UR7 is connected to one end of capacitor UC20. The other end of capacitor UC20 is grounded. Pin 19 of MCU chip 3 is connected to resistor UR22 and capacitor UC33 in sequence and then grounded. Pin 22 of MCU chip 3 is connected to resistor UR23 and capacitor UC34 in sequence and then grounded. Pin 23 of MCU chip 3 is connected to resistor UR24 and capacitor UC35 in sequence and then grounded. Pin 25 of MCU chip 3 is connected to one end of capacitors UC14 and UC15. The other ends of capacitors UC14 and UC15 are grounded. Pin 26 of MCU chip 3 is connected to one end of resistor UR9. The other end of resistor UR9 is connected to capacitor UC27 and the DOOR_LED_CON network, respectively, which can adjust the brightness of the door control indicator light. Pin 30 of MCU chip 3 is connected to one end of resistor UR11. The other end of resistor UR11 is connected to one end of resistor UR13 and the ER_SCL network. The other end of resistor UR13 is connected to 3.3V. This connection is used for error detection of the serial clock signal. Pin 31 of MCU chip 3 is connected to one end of resistor UR10. The other end of resistor UR10 is connected to one end of resistor UR12 and the ER_SDA network. The other end of resistor UR12 is connected to 3.3V. This connection is used for error detection of the serial data signal. Pin 34 of MCU chip 3 is connected to the Sf network to detect the status of the lamp and provide timely feedback. Pin 37 of MCU chip 3 is connected to one end of resistors UR20 and UR21. The other end of resistor UR20 is connected to 5V, and the other end of UR21 is grounded. This connection is used for 5V voltage detection. Pin 39 of MCU chip 3 is connected to the DATA network and is one of the test points for repeated software programming. Pin 40 of MCU chip 3 is connected to the CLOCK network and is one of the test points for repeated software programming. Pin 43 of MCU chip 3 is connected to the Backlight_KD network, used to detect whether the backlight button is pressed. Pin 44 of MCU chip 3 is connected to the Rightreading light_KD network, used to detect whether the right reading light button is pressed.Pin 45 of MCU chip 3 is connected to the Left reading light_KD network, used to detect whether the left reading light button is pressed. Pin 46 of MCU chip 3 is connected to the Door control indicator_KD network, used to detect whether the door control indicator button is pressed. Pin 47 of MCU chip 3 is connected to the Front interior light_KD network, used to detect whether the front interior light button is pressed.

[0083] like Figure 10 As shown, the feedback detection circuit includes resistor SR5, transient voltage suppression diode ST1, capacitor SC2, resistor SR4, NMOS transistor SQ1, resistor SR3, capacitor SC1, and resistor SR2. One end of resistor SR5 is connected to the positive network of the vehicle power supply, and the other end is connected to the status feedback signal line. One end of transient voltage suppression diode ST1 and capacitor SC2 are connected to the status feedback signal line, and the other end is grounded. One end of resistor SR4 is connected to the status feedback signal line, and the other end is connected to the drain (D) terminal of NMOS transistor SQ1. The source (S) terminal of NMOS transistor SQ1 is grounded. One end of resistor SR3, capacitor SC1, and resistor SR2 is connected to the gate (G) terminal of NMOS transistor SQ1, and the other end of resistor SR3 and capacitor SC1 is grounded. The other end of resistor SR2 is connected to the Sf network.

[0084] The state feedback hardwire from vehicle body 1 is connected to the drain (D) of NMOS transistor SQ1 via transient voltage suppression diode ST1 and capacitor SC2. Resistor SR4 is the bias resistor for the drain of NMOS transistor SQ1. Resistor SR5 is pulled up to the power supply line. The gate (G) of NMOS transistor SQ1 is connected to the Sf network via resistor SR2, which is connected to pin 34 of MCU chip 3. MCU chip 3 operates on a high-level active-high logic for the Sf network. When a light malfunctions, such as an open-circuit LED, the Sf network sends a high-level command to MCU chip 3. MCU chip 3 then interacts with vehicle body 1 via the LIN signal to inform the driver of the malfunction, providing timely warning.

[0085] This embodiment's front interior lighting circuit, based on the existing interior lights, adds door control indicator lights, button backlights, and left and right reading lights, making the front interior lighting more functional and comprehensive, thus improving the passenger's in-vehicle experience. In addition to the hard-wired input of door control and backlight signals, a LIN signal line is added, with only one master node and many slave nodes. This master-slave communication structure improves the orderliness and reliability of signal transmission between the lights and the vehicle body 1. Synchronization also adds byte verification and error detection functions during signal transmission, improving signal accuracy. The synchronous redundancy design adds hard-wired status feedback for all lights, promptly relaying any abnormal statuses to the vehicle body 1, providing timely alerts. Through the information interaction between the LIN signal and the microcontroller, the brightness of the interior lights and left and right reading lights can be adjusted to meet different user needs.

[0086] In the front indoor lighting circuit, the left and right reading lights adopt a linear circuit scheme to reduce power loss, while the backlight adopts a resistive drive scheme, which is easy to pass electromagnetic compatibility (EMC test) and has a low cost.

[0087] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A front chamber light circuit, characterized by, include: The front-end protection module (2) has its input end connected to the positive terminal of the vehicle body (1) power supply, and its output end connected to the power input terminal of the MCU control module and the power input terminal of the drive module respectively. The MCU control module includes an MCU chip (3), a 5V power supply unit (4), a LIN communication unit (5), and a data storage unit (6). The input terminal of the 5V power supply unit (4) is connected to the output terminal of the front-end protection module (2), and its output terminal is connected to the power supply pin of the MCU chip (3). The LIN signal line of the LIN communication unit (5) is connected to the LIN bus of the vehicle body (1), and its data line is connected to the communication pin of the MCU chip (3). The data storage unit (6) is connected to the MCU chip (3) through an I²C or SPI bus. Multiple function button modules, one end of each button module is grounded, and the other end is connected to the GPIO input pin of the MCU chip (3); A driving module composed of multiple LED driving circuits, with the input terminal of each driving circuit connected to the PWM output pin of the MCU chip (3) and the output terminal connected to the positive terminal of the corresponding LED load; Multiple LED lighting units are provided, with the negative terminal of each LED lighting unit grounded and the positive terminal connected to the output terminal of the corresponding driving circuit.

2. The front indoor light circuit according to claim 1, characterized in that: The multiple function button module includes: The door control indicator button module (7) includes a door control indicator button SD1. The second pin of the door control indicator button SD1 is connected to a 5V power supply. Its first pin is connected in sequence to a voltage divider resistor DR3, a voltage divider resistor DR8, a Zener diode DD3 and a voltage divider resistor DF7, and then connected to the 46th pin PC10 of the MCU chip (3). The front interior light button module (8) includes a front interior light button SF1. The second pin of the front interior light button SF1 is connected to a 5V power supply. Its first pin is connected in sequence to a voltage divider resistor FR1, a voltage divider resistor FR3, a Zener diode FD1 and a voltage divider resistor FR2, and then connected to the 47th pin PC11 of the MCU chip (3). The left reading light button module (9) includes a left reading light button SL1. The second pin of the left reading light button SL1 is connected to a 5V power supply. Its first pin is connected in sequence to a voltage divider resistor LR1, a voltage divider resistor LR3, a Zener diode LD1 and a voltage divider resistor LR2, and then connected to the 45th pin PC9 of the MCU chip (3). The right reading light button module (10) includes a right reading light button SR1. The second pin of the right reading light button SR1 is connected to a 5V power supply. Its first pin is connected in sequence to a voltage divider resistor RR1, a voltage divider resistor RR5, a Zener diode RD4, and a voltage divider resistor RR4, and then connected to the 44th pin PG7 of the MCU chip (3). The backlight button module (11) includes a backlight button SB1. The second pin of the backlight button SB1 is connected to a 5V power supply. Its first pin is connected in sequence to a voltage divider resistor BR1, a voltage divider resistor BR3, a Zener diode RD1 and a voltage divider resistor BR2, and then connected to the 43rd pin PG6 of the MCU chip (3).

3. The front indoor light circuit according to claim 1, characterized in that: Multiple LED driver circuits include: The reading light driving circuit (18) includes a left reading light driving circuit and a right reading light driving circuit. The output of the left reading light driving circuit is connected to pin 1 PH8 of the MCU chip (3), and the output of the right reading light driving circuit is connected to pin 7 PH6 of the MCU chip (3). The input of the reading light driving circuit is connected to the first front-end protection circuit. The door control light driver circuit (19) has its output terminal connected to pin PB0 of the MCU chip (3) on the 26th pin. Indoor light driving circuit (20) and key backlight driving circuit (21).

4. The front cabin light circuit of claim 3, wherein: The first front-end protection circuit includes a filter capacitor RC1, a filter capacitor RC5, a common-mode rejection inductor RL3, a resistor R9, a capacitor RC4, a transient voltage suppression diode RT1, a capacitor RC14, a capacitor RC2, a capacitor RC3, a reverse connection protection diode RD3, and a capacitor RC13. The filter capacitors RC1 and RC5 are connected in parallel, with one end connected to the positive network of the vehicle power supply and the other end grounded. The common-mode rejection inductor RL3 includes a first terminal, a second terminal, a third terminal, and a fourth terminal. The first terminal is connected to the positive network of the vehicle power supply, and the second and third terminals are grounded. One end of the resistor R9 is connected to the first terminal, and the other end is connected to the fourth terminal. One end of the capacitors RC4, RT1, RC14, RC2, and RC3 is connected to the fourth terminal, and the other ends are all grounded. The positive terminal of the reverse connection protection diode RD3 is connected to the fourth terminal, and its negative terminal is connected to one end of the capacitor RC13, and is also connected to the input terminals of the left and right reading light drive circuits. The other end of the capacitor RC13 is grounded. The left reading light driver circuit includes resistor R4, transistor RQ3, reference diode RD2, capacitor RC7, filter capacitor C1, first left reading LED RL1, second left reading LED RL2, absorption capacitor LC1, absorption capacitor LC2, resistor R5, NMOS transistor RQ1, resistor R8, capacitor RC11, and resistor R7. The base of transistor RQ3 is connected to one end of filter capacitor C1, reference diode RD2 and resistor R4. The other end of filter capacitor C1 and reference diode RD2 is grounded. The other end of resistor R4 is connected to the output of the first front-end protection circuit. Capacitor RC7 is connected in parallel with reference diode RD2. The drain of NMOS transistor RQ1 is connected to one end of resistor R5. The other end of resistor R5 is connected to the emitter of transistor RQ3. The source of NMOS transistor RQ1 is grounded. The gate of NMOS transistor RQ1 is connected to one end of resistor R8, capacitor RC11 and resistor R7. The other end of resistor R8 and capacitor RC11 is grounded. The other end of resistor R7 is connected to pin PH8 of MCU chip (3). The collector of transistor RQ3 is connected from bottom to top to resistor R12, first left reading LED RL1, and second left reading LED RL2, and then to the output of the first front-end protection circuit. The first left reading LED RL1 and the second left reading LED RL2 are connected in parallel to absorption capacitor LC1 and absorption capacitor LC2, respectively. The right reading light driving circuit includes resistor R2, transistor RQ4, reference diode RD1, filter capacitor RC12, capacitor RC5, first right reading LED RR2, second right reading LED RR3, absorption capacitor RC9, absorption capacitor RC8, resistor R14, resistor R13, resistor R1, NMOS transistor RQ2, resistor R3, capacitor RC10, and resistor R6. The base of transistor RQ4 is connected to one end of filter capacitor RC12, reference diode RD1 and resistor R2. The other end of filter capacitor RC12 and reference diode RD1 is grounded. The other end of resistor R2 is connected to the output of the first front-end protection circuit. Capacitor RC5 is connected in parallel with reference diode RD1. The drain of NMOS transistor RQ2 is connected to one end of resistor R1. The other end of resistor R1 is connected to the emitter of transistor RQ4. The source of NMOS transistor RQ2 is grounded. The gate of NMOS transistor RQ2 is connected to one end of resistor R3, capacitor RC10 and resistor R6. The other end of resistor R3 and capacitor RC10 is grounded. The other end of resistor R6 is connected to pin 7 PH6 of MCU chip (3). The collector of transistor RQ3 is connected from bottom to top to resistor R14, second right reading LED RR3, and first right reading LED RR2, and then to the output of the first front-end protection circuit. The first right reading LED RR2, the second right reading LED RR3, and resistor R14 are connected in parallel to absorption capacitors RC9, RC8, and resistor R13, respectively.

5. The front indoor light circuit according to claim 3, characterized in that: The input terminal of the gate control light driving circuit (19) is connected to the gate control signal detection circuit. The gate control signal detection circuit includes transient voltage suppression diode DT1, diode DD2, resistor DR1 and resistor DR2. One end of resistor DR1 is connected to 5V voltage, and the other end is connected between diode DD2 and resistor DR2. The other end of resistor DR2 is connected to pin 6 PH5 of MCU chip (3). The other end of diode DD2 is connected to one end of transient voltage suppression diode DT1 and connected to the input terminal of the gate control light driving circuit. The other end of transient voltage suppression diode DT1 is grounded. The gate control light driver circuit (19) includes an NMOS transistor DQ1, a resistor DR4, a resistor RD5, a gate control LED DL1, and a capacitor DC2. The gate control LED DL1 and the capacitor DC2 are connected in parallel. One end of the LED is connected to the output of the gate control signal detection circuit, and the other end is connected to one end of the resistor DR5. The other end of the resistor DR5 is connected to the drain of the NMOS transistor DQ1. The gate of the NMOS transistor DQ1 is connected to pin PB0 of the MCU chip (3) through the resistor DR4.

6. The front cabin light circuit of claim 3, wherein: The input terminal of the indoor lamp driving circuit (20) is connected to the second front-end protection circuit. The second front-end protection circuit includes transient suppression diode IT1, capacitor IC1, capacitor IC2 and anti-reverse diode ID1. One end of transient suppression diode IT1, capacitor IC1 and capacitor IC2 is connected to the positive terminal network of the vehicle body power supply, and the other end is grounded. The positive terminal of diode ID1 is connected to the positive terminal of the vehicle body power supply, and its negative terminal is connected to the input terminal of the indoor lamp driving circuit. The indoor light driver circuit (20) includes transistor IQ1, filter capacitor IC3, resistor IR7, base bias diode ID2, filter capacitor IC4, resistor IR1, resistor IR6, first indoor LED IL1, second indoor LED IL2, third indoor LED IL3, fourth indoor LED IL4, capacitor IC5, capacitor IC6, capacitor IC7, capacitor IC8, Zener diode ID3, Zener diode ID4, current limiting resistor IR2, current limiting resistor IR3, current limiting resistor IR4 and current limiting resistor IR5. The base of transistor IQ1 is connected to one end of filter capacitor IC3 and resistor IR7. The other end of filter capacitor IC3 is grounded. The other end of resistor IR7 is connected to resistor IR1 and one end of base bias diode ID2. The other end of resistor IR1 is connected to the output terminal of the second front-end protection circuit. The other end of base bias diode ID2 is grounded. Filter capacitor IC4 is connected in parallel across the two ends of bias diode ID2. The first indoor LED light IL1 and the second indoor LED light IL2 are connected in series, with capacitors IC5 and IC6 connected in parallel between them respectively. The third indoor LED light IL3 and the fourth indoor LED light IL4 are connected in series, with capacitors IC7 and IC8 connected in parallel between them respectively. The input terminals of the third indoor LED light IL3 and the first indoor LED light IL1 are connected to the output terminal of the second front-end protection circuit. The output terminals of the second indoor LED light IL2 and the fourth indoor LED light IL4 are connected to each other. One end of current-limiting resistors IR2 and IR3 is connected to the output terminal of Zener diode ID3, and the other end is connected to the collector of transistor IQ1. The input terminal of Zener diode ID3 is connected to the output terminals of the second indoor LED IL2 and the fourth indoor LED IL4. One end of current-limiting resistors IR3 and IR4 is connected to the output terminal of Zener diode ID4, and the other end is connected to the collector of transistor IQ1. The input terminal of Zener diode ID4 is connected to the output terminals of the second indoor LED IL2 and the fourth indoor LED IL4.

7. The front compartment light circuit of claim 3, wherein: The input terminal of the button backlight driving circuit (21) is connected to the third front-end protection circuit. The third front-end protection circuit includes diode BT1, capacitor BC3, first resistor BR6 and diode BD2. Diode BT1, capacitor BC3 and first resistor BR6 are connected in parallel. One end is connected to the backlight power input network and the other end is grounded. The positive terminal of diode BD2 is connected to the backlight power input network and the other end is connected to the button backlight driving circuit. The backlight driving circuit (21) includes a second backlight LED BC2, a first backlight LED BC1, a capacitor BC2, a capacitor BC1, a second resistor BR4, a third resistor BR5 and a fourth resistor BR7. One end of the second backlight LED BL2 is connected to the output end of the third front-end protection circuit, and the other end is connected to one end of the first backlight LED BL1. The second backlight LED BL2 and the first backlight LED BL1 are connected in parallel with capacitors BC2 and BC1, respectively. The second resistor BR4, the third resistor BR5, and the fourth resistor BR7 are connected in parallel, with one end connected to the other end of the first background light LED BL1, and the other ends are all grounded.

8. The front cabin light circuit of claim 1, wherein: The 5V power supply unit (4) includes chip U1, capacitors UC3, UC2, UC1, UC32, chip U3, capacitors UC21, UC31, UC22, UC4, Zener diode UD1, and resistor UR19. Pin 8 of chip U1 is connected to the positive terminal of the vehicle power supply. One end of capacitors UC1 and UC32 is connected to pin 8 of chip U1, and the other end is grounded. Pin 1 of chip U1 is connected to 5V voltage. One end of capacitors UC3 and UC2 is connected to pin 1 of chip U1, and the other end is grounded. Pin 1 of chip U3 is connected to the positive network of the vehicle's power supply. One end of capacitor UC21 is connected to pin 1 of chip U3, and the other end is connected to pin 2 of chip U3. Pin 2 of chip U3 is grounded. Pin 3 of chip U3 is connected to a 3.3V voltage. One end of capacitors UC31, UC22, and UC4 is connected to pin 3 of chip U1. The other ends of capacitors UC31 and UC22 are connected to pin 4 of chip U3. Pin 2 of chip U3 is grounded, and the other end of capacitor UC4 is grounded. The negative terminal of Zener diode UD1 is connected to pin 3 of chip U1, and its positive terminal is connected to one end of resistor UR19. The other end of resistor UR19 is grounded.

9. The front compartment light circuit of claim 1, wherein: The MCU chip (3) has its pin 1 connected to one end of resistor UR2, and the other end of resistor UR2 connected to one end of capacitor UC23 and resistor UR27 respectively. The other end of capacitor UC23 is grounded, and the other end of resistor UR27 is connected to the L_READ_CON network. The MCU chip (3) has its pin 3 connected to one end of resistor UR29, and the other end of resistor UR29 is connected to the CO_IN network. The MCU chip (3) has its pin 4 connected to one end of resistor UR30, and the other end of resistor UR30 is connected to the CO_OUT network. The MCU chip (3) has its pin 5 connected to the RST network. The MCU chip (3) has its pin 6 connected to one end of resistor UR5, and the other end of resistor UR5 is connected to the DOOR_IN_SIG network. The MCU chip (3) has its pin 7 connected to one end of resistor UR4, and the other end of resistor UR4 is connected to capacitor UC26 and resistor UR28 respectively. One end of capacitor UC26 is grounded, the other end of resistor UR28 is connected to the R_READ_CON network, pin 10 of MCU chip (3) is connected to one end of capacitors UC9, UC8 and UC7 and grounded, pin 11 of MCU chip (3) is connected to the other end of capacitors UC9, UC8 and UC7 and connected to 3.3V voltage, pin 13 of MCU chip (3) is connected to one end of capacitors UC12, UC11 and UC10 and grounded, and pin 14 of MCU chip (3) is connected to the other end of capacitors UC12, UC11 and UC10 and connected to 3.3V voltage.With a voltage of 3V, pin 15 of MCU chip (3) is connected to one end of capacitor UC30, and the other end of capacitor UC30 is grounded. Pin 16 of MCU chip (3) is connected to one end of capacitor UC13, and the other end of capacitor UC13 is grounded. Pin 17 of MCU chip (3) is connected to one end of capacitor UC29 and resistor UR6, and the other end of capacitor UC29 is grounded. The other end of resistor UR6 is connected to one end of capacitor UC19, and the other end of capacitor UC19 is grounded. Pin 18 of MCU chip (3) is connected to one end of capacitor UC28 and resistor UR7. The other end of capacitor UC28 is grounded, the other end of resistor UR7 is connected to one end of capacitor UC20, the other end of capacitor UC20 is grounded, pin 19 of MCU chip (3) is connected to resistor UR22 and capacitor UC33 in sequence and then grounded, pin 22 of MCU chip (3) is connected to resistor UR23 and capacitor UC34 in sequence and then grounded, pin 23 of MCU chip (3) is connected to resistor UR24 and capacitor UC35 in sequence and then grounded, pin 25 of MCU chip (3) is connected to one end of capacitor UC14 and capacitor UC15, and the other end of capacitor UC14 and capacitor UC15 is grounded. The other end is grounded. Pin 26 of MCU chip (3) is connected to one end of resistor UR9. The other end of resistor UR9 is connected to capacitor UC27 and the DOOR_LED_CON network. Pin 30 of MCU chip (3) is connected to one end of resistor UR11. The other end of resistor UR11 is connected to one end of resistor UR13 and the ER_SCL network. The other end of resistor UR13 is connected to 3.3V. Pin 31 of MCU chip (3) is connected to one end of resistor UR10. The other end of resistor UR10 is connected to one end of resistor UR12 and the ER_SDA network. The other end of resistor UR12 is connected to 3.3V. Pin 34 of MCU chip (3) is connected to the Sf network. Pin 37 of MCU chip (3) is connected to one end of resistors UR20 and UR21. The other end of resistor UR20 is connected to 5V, and the other end of UR21 is grounded. Pin 39 of MCU chip (3) is connected to the DATA network. Pin 40 of MCU chip (3) is connected to the CLOCK network. Pin 43 of MCU chip (3) is connected to the Backlight_KD network. Pin 44 of MCU chip (3) is connected to the Right reading light_KD network. Pin 45 of MCU chip (3) is connected to the Left reading light_KD network. Pin 46 of MCU chip (3) is connected to the Door control indicator_KD network. Pin 47 of MCU chip (3) is connected to the Front interiorlight_KD network.

10. The front compartment light circuit of claim 9, wherein: It also includes a feedback detection circuit, which includes a resistor SR5, a transient voltage suppression diode ST1, a capacitor SC2, a resistor SR4, an NMOS transistor SQ1, a resistor SR3, a capacitor SC1, and a resistor SR2. One end of the resistor SR5 is connected to the positive network of the vehicle body power supply, and the other end is connected to the status feedback signal line. One end of the transient voltage suppression diode ST1 and the capacitor SC2 are connected to the status feedback signal line, and the other end is grounded. One end of the resistor SR4 is connected to the status feedback signal line, and the other end is connected to the drain (D) terminal of the NMOS transistor SQ1. The source (S) terminal of the NMOS transistor SQ1 is grounded. One end of the resistor SR3, the capacitor SC1, and the resistor SR2 are connected to the gate (G) terminal of the NMOS transistor SQ1, and the other end of the resistor SR3 and the capacitor SC1 is grounded. The other end of the resistor SR2 is connected to the Sf network.

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