Digital circuit decoding circuit for LED car lamp

Abstract

The utility model discloses a digital circuit decoding circuit for an LED vehicle lamp, which comprises a low-brightness signal input end, a first rectifier module, a second rectifier module, a first MOS (Metal Oxide Semiconductor) tube, a second MOS tube, a third MOS tube, a power management chip, a voltage division module, an LED module, a high-brightness signal input end, an MCU (Microprogrammed Control Unit) control chip, a low-brightness signal input end, a first rectifier module and a power management chip which are connected in sequence, the voltage division module is connected between the first rectification module and the power management chip, and the first MOS tube is connected between the low-light signal input end and the voltage division module; the high-brightness signal input end, the second rectifier module and the power management chip are sequentially connected, the second MOS tube is connected between the MCU control chip and the power management chip, and after the second MOS tube is conducted, the MCU control chip outputs a PWM signal to the power management chip to control the output power of the power management chip; and the power management chip is connected with the LED module through the third MOS tube so as to output power to control the LED module to work.

Description

Technical Field:

[0001] The utility model relates to the technical field of LED vehicle lamps, and particularly refers to a digital circuit decoding circuit for LED vehicle lamps. Background Art:

[0002] At present, due to limited volume and insufficient heat dissipation, the power of automotive LED lamps in the aftermarket cannot reach that of the original halogen lamps. This can cause an alarm on the dashboard or abnormal lamp functions during vehicle startup self-check. Therefore, the common solution is to install an external resistor decoder to make up for the insufficient power to pass the self-check.

[0003] An automotive LED decoder is used to solve the problem of the vehicle dashboard's lamp failure light turning on when upgrading the original halogen bulb to an LED headlamp. Its principle is to increase the current in the automotive headlamp circuit. After installing the decoder, when the vehicle's on-board computer performs a self-check, it detects that the headlamp current is normal and the failure light will not turn on, which means passing the decoding.

[0004] The conventional products on the market currently are external resistor decoders. The overall external dimensions of the products are large, and there is a problem of having no suitable space position to fixedly install the external decoder. Or there are various abnormal conditions such as the high temperature of the decoder causing deformation and damage to the installation surface, increasing the modification cost and difficulty, and reducing the customer's intention to modify.

[0005] Chinese Utility Model Patent No. 202320621057.8 discloses an internal decoder structure for an LED vehicle lamp. The internal decoder structure for the LED vehicle lamp includes a lamp housing and a connector for connecting to the vehicle lamp socket. The connector is arranged at the rear end of the lamp housing, and a decoding module is arranged at the front end of the lamp housing. The decoding module includes a mounting seat and a decoding resistor. The mounting seat is fixedly installed on the front end of the lamp housing, and the decoding resistor is encapsulated in the inner cavity of the mounting seat. The decoding resistor is powered by the vehicle power supply. By placing the decoding resistor in the mounting seat made of ceramic material and then installing the mounting seat on the lamp housing, this internal decoder structure for the LED vehicle lamp changes the external resistor decoder into an internal one. The product is small, beautiful, cost-effective, easy and simple to modify, and can achieve plug-and-play and rapid decoding. A heat insulation plate is used to block the heat between the mounting seat and the lamp housing, so that the heat generated by the decoding resistor does not transfer to the lamp housing and will not affect the circuit and structure.

[0006] The above-mentioned built-in decoder structure of the LED car light changes the external resistor decoder to an internal one. However, the overall volume of this decoding module is relatively large and requires a large installation space, that is, the lamp housing needs to be provided with a large installation space for the decoding module to be installed, which in turn makes the volume of the entire LED car light larger. For small LED car lights such as turn signal lights, brake lights, and reverse lights, it may not be possible to install them due to insufficient internal space; when the resistor decoder is working, the excess power is converted into heat through the resistor, resulting in the resistor decoder generating a huge amount of heat, which easily causes the melting of automotive plastic parts or wires and leads to safety accidents, and it is not safe and reliable to use.

[0007] In view of this, the inventor proposes the following technical solutions. Summary of the Utility Model:

[0008] The purpose of the present utility model is to overcome the deficiencies of the prior art and provide a digital circuit decoding circuit for LED car lights.

[0009] To solve the above technical problems, the present utility model adopts the following technical solutions: The digital circuit decoding circuit for LED car lights includes a low-brightness signal input terminal, a first rectification module, a power management chip, a voltage division module, a first MOS transistor, an LED module, a third MOS transistor, a high-brightness signal input terminal, a second rectification module, an MCU control chip, and a second MOS transistor arranged on a PCB board. The low-brightness signal input terminal, the first rectification module, and the power management chip are connected in sequence. The voltage division module is connected between the first rectification module and the power management chip, and the first MOS transistor is connected between the low-brightness signal input terminal and the voltage division module to control the input voltage of the dimming pin of the power management chip by the voltage division module; the high-brightness signal input terminal, the second rectification module, and the power management chip are connected in sequence. The high-brightness signal input terminal is connected to the second MOS transistor to control the on / off of the second MOS transistor. The second MOS transistor is also connected between the MCU control chip and the power management chip. When the second MOS transistor is turned on, the MCU control chip outputs a PWM signal to the power management chip to control the output power of the power management chip; the LED module is connected to the first rectification module and the second rectification module; the power management chip is connected to the LED module through the third MOS transistor to output power to control the operation of the LED module.

[0010] Furthermore, in the above technical solution, a first voltage stabilization module is further arranged between the first rectification module and the voltage division module. The first voltage stabilization module includes a first resistor connected to the first rectification module and a first voltage stabilization diode connected to the first resistor.

[0011] Furthermore, in the above technical solution, the output ends of the first rectification module and the second rectification module are connected, and a filtering module is connected. The filtering module includes a capacitor C1 and a capacitor C2 connected in parallel with each other. One end of the capacitor C1 is connected to the output ends of the first rectification module and the second rectification module, and the other end of the capacitor C1 is connected to the ground.

[0012] Furthermore, in the above technical solution, the voltage division module includes a first voltage division resistor R13 and a second voltage division resistor R14 connected in series with each other. The first voltage division resistor R13 is connected to the first resistor. The cathode of the first voltage stabilizing diode is connected to the connection line between the first voltage division resistor R13 and the first resistor. The anode of the first voltage stabilizing diode is grounded. The second voltage division resistor R14 is connected to the first MOS transistor.

[0013] Furthermore, in the above technical solution, the D pole of the first MOS transistor is connected to the second voltage division resistor R14 of the voltage division module. The S pole of the first MOS transistor is grounded. The G pole of the first MOS transistor is connected to the resistor R5 and the first diode and then connected to the low-brightness signal input terminal.

[0014] Furthermore, in the above technical solution, the D pole of the second MOS transistor is connected to the resistor R4 and then connected to the dimming pin of the power management chip. The S pole of the second MOS transistor is connected to the DIM pin of the MCU control chip. The G pole of the second MOS transistor is connected to the resistor R2 and the second diode and then connected to the high-brightness signal input terminal.

[0015] Furthermore, in the above technical solution, the resistor R2 is also connected to the VCC pin of the MCU control chip. The resistor R2 is also connected to the second voltage stabilizing diode and then grounded. The VCC pin of the MCU control chip is also connected to a capacitor C3 for charging and then grounded.

[0016] Furthermore, in the above technical solution, the DRV pin of the power management chip is connected to the resistor R8 and then connected to the G pole of the third MOS transistor. The S pole of the third MOS transistor is grounded. The D pole of the third MOS transistor is connected to the LED module.

[0017] Furthermore, in the above technical solution, the LED module includes multiple LEDs connected in series and an inductor L1 connected to the LEDs. The inductor L1 is connected to the D pole of the third MOS transistor. The other end of the LED connected to the inductor L1 is connected to the resistor R11 and then connected to the output ends of the first rectification module and the second rectification module.

[0018] Furthermore, in the above technical solution, the D pole of the third MOS transistor is also connected to the anode of the third diode. The cathode of the third diode is connected to the other end of the resistor R11 connected to the LED.

[0019] After adopting the above technical solution, the utility model has the following beneficial effects compared with the prior art: The utility model uses an MCU control chip to control the dimming power of the power management chip, keeping it in a high-power state for 3 seconds, thereby making up for the insufficient power. Subsequently, the power is gradually reduced to suppress the continuous rise of its heat. The high power in the early stage enables the vehicle computer to self-check without faults, enabling the LED headlight to achieve the same power as the original vehicle halogen lamp to meet the usage requirements. At the same time, compared with the resistance decoder, since the circuit of the utility model is integrated on the PCB board, its volume becomes smaller, occupying less installation space, and it can be applied to small LED headlights such as turn signal lights, brake lights, and reverse lights. At the same time, the utility model does not generate a large amount of heat during operation, which can reduce the heat generation of the entire LED headlight, ensure the working quality of the LED headlight, and thus is not likely or even will not cause safety accidents caused by the melting of automotive plastic parts or wires, making it safer and more reliable to use. Brief Description of the Drawings:

[0020] Figure 1 It is the circuit diagram of the utility model. Detailed Embodiment:

[0021] The utility model will be further described below in conjunction with specific embodiments and the drawings.

[0022] See Figure 1As shown in the figure, it is a digital circuit decoding circuit for an LED headlight, which includes a low-brightness signal input terminal 1, a first rectification module 2, a power management chip 101, a voltage division module 3, a first MOS transistor 102, an LED module 4, a third MOS transistor 103, a high-brightness signal input terminal 5, a second rectification module 6, an MCU control chip 104, and a second MOS transistor 105 arranged on a PCB board. Among them, the low-brightness signal input terminal 1, the first rectification module 2, and the power management chip 101 are connected in sequence. The voltage division module 3 is connected between the first rectification module 2 and the power management chip 101, and the first MOS transistor 102 is connected between the low-brightness signal input terminal 1 and the voltage division module 3 to control the input voltage of the dimming pin of the power management chip 101 by the voltage division module 3. The high-brightness signal input terminal 5, the second rectification module 6, and the power management chip 101 are connected in sequence. The high-brightness signal input terminal 5 is connected to the second MOS transistor 105 to control the on / off of the second MOS transistor 105. The second MOS transistor 105 is also connected between the MCU control chip 104 and the power management chip 101. After the second MOS transistor 105 is turned on, the MCU control chip 104 outputs a PWM signal to the power management chip 101 to control the output power of the power management chip 101. The LED module 4 is connected to the first rectification module 2 and the second rectification module 6. The power management chip 101 is connected to the LED module 4 through the third MOS transistor 103 to output power to control the operation of the LED module 4. In specific use, when the low-brightness signal input terminal 1 is at a high level, it is in a low-brightness output state. The first MOS transistor 102 is immediately turned on, and the input voltage is divided by the voltage division module 3 and then a stable voltage is input to the dimming pin DIM of the 3rd pin of the power management chip 101, thereby controlling the power management chip 101 to output a stable power. The power size is determined by the stable voltage of the dimming pin DIM of the 3rd pin of the power management chip 101, and further ensures the stable operation of the LED module. When the high-brightness signal input terminal 5 is at a high level, it is in a high-brightness output state. The MCU control chip 104 is powered on and operates, and the second MOS transistor 105 is in a conducting state. A PWM signal is output from the 5th pin of the MCU control chip 104 through the second MOS transistor 105 to the dimming pin DIM of the 3rd pin of the power management chip 101, thereby controlling the output power of the power management chip 101. The output power size and change mode are determined by the PWM signal, and further ensures the stable operation of the LED module. The PWM control mode of the MCU control chip 104 is: after power-on, it first outputs 100% full load. At the same time, the MCU control chip 104 starts timing. After 3 seconds of full-load output, the output power linearly starts to decrease from the initial 100% until it reaches 20% and then stably operates for a long time without further decrease. The power decrease process is required to be completed in about 10 seconds.That is to say, the present utility model uses an MCU control chip to control the dimming power of the power management chip, so that it maintains a high-power state for 3 seconds, thereby making up for the insufficient power. Subsequently, the power is gradually reduced to suppress the continuous rise of its heat. The high power in the early stage enables the vehicle computer to self-check without faults, enabling the LED headlight to achieve the same power as the original vehicle halogen lamp to meet the usage requirements. At the same time, compared with the resistance decoder, since the circuit of the present utility model is integrated on the PCB board, its volume becomes smaller, and the installation space required is smaller. It can be applied to small LED headlights such as turn signal lights, brake lights, and reverse lights. At the same time, the present utility model does not generate a large amount of heat during operation, which can reduce the heat generation of the entire LED headlight, ensure the working quality of the LED headlight, and thus is not likely or even will not cause safety accidents caused by the melting of automotive plastic parts or wires, making it safer and more reliable to use.

[0023] The low-brightness signal input terminal 1 includes an L2 terminal and an L3 terminal. Among them, when any one of the L2 terminal and the L3 terminal is at a high level, it is in the low-brightness output state.

[0024] The high-brightness signal input terminal 5 includes an H1 terminal and an H4 terminal. Among them, when any one of the H1 terminal and the H4 terminal is at a high level, it is in the high-brightness output state.

[0025] A first voltage stabilizing module 8 is further provided between the first rectifying module 2 and the voltage dividing module 3. The first voltage stabilizing module 8 includes a first resistor 81 connected to the first rectifying module 2 and a first voltage stabilizing diode 82 connected to the first resistor 81. The voltage dividing module 3 includes a first voltage dividing resistor R13 and a second voltage dividing resistor R14 connected in series. The first voltage dividing resistor R13 is connected to the first resistor 81. The cathode of the first voltage stabilizing diode 82 is connected to the connection line between the first voltage dividing resistor R13 and the first resistor 81. The anode of the first voltage stabilizing diode 82 is grounded. The second voltage dividing resistor R14 is connected to the first MOS transistor 102. During operation, when the input terminal of the low-brightness signal input terminal 1 is at a high level, it is in the low-brightness output state, and the first MOS transistor 102 is immediately turned on. The input voltage is regulated by the first resistor 81 and the first voltage stabilizing diode 82 and then divided by the first voltage dividing resistor R13 and the second voltage dividing resistor R14 of the voltage dividing module 3 to input a stable voltage to the dimming pin DIM of the 3rd pin of the power management chip 101, thereby ensuring that the power management chip 101 outputs a stable power and ensuring the stable operation of the LED module.

[0026] The output terminals of the first rectifying module 2 and the second rectifying module 6 are connected and connected to a filtering module 9. The filtering module 9 includes a capacitor C1 and a capacitor C2 connected in parallel. One end of the capacitor C1 is connected to the output terminals of the first rectifying module 2 and the second rectifying module 6, and the other end of the capacitor C1 is connected to the ground.

[0027] The D pole of the first MOS transistor 102 is connected to the second voltage dividing resistor R14 of the voltage dividing module 3. The S pole of the first MOS transistor 102 is grounded. The G pole of the first MOS transistor 102 is connected to the resistor R5 and the first diode 106 and then connected to the low brightness signal input terminal 1. When working, when a high level is input to the low brightness signal input terminal 1, the G pole of the first MOS transistor 102 controls its D pole and S pole to conduct, grounding the second voltage dividing resistor R14.

[0028] The D pole of the second MOS transistor 105 is connected to the resistor R4 and then connected to the dimming pin of the power management chip 101. The S pole of the second MOS transistor 105 is connected to the DIM pin of the MCU control chip 104. The G pole of the second MOS transistor 105 is connected to the resistor R2 and the second diode 107 and then connected to the high brightness signal input terminal 5. When a high level is input to the high brightness signal input terminal 5, the G pole of the second MOS transistor 105 controls its D pole and S pole to conduct, connecting the dimming pin of the power management chip 101 and the DIM pin of the MCU control chip 104, and then enabling

[0029] A PWM signal is output from the 5th pin of the MCU control chip 104 through the second MOS transistor 105 to the 3rd pin dimming pin DIM of the power management chip 101, thereby controlling the output power of the power management chip 101. The magnitude and change mode of the output power are determined by the PWM signal, and then ensuring the stable operation of the LED module.

[0030] The resistor R2 is also connected to the VCC pin of the MCU control chip 104. The resistor R2 is also connected to the second voltage stabilizing diode 108 and then grounded, and then enabling the resistor R2 to input a stable voltage to the VCC pin of the MCU control chip 104, ensuring the working quality of the MCU control chip 104 and protecting the MCU control chip 104 at the same time; the VCC pin of the MCU control chip 104 is also connected to a capacitor C3 for charging and then grounded. Among them, to prevent the MCU control chip 104 from continuing to work after power off, the capacitance of the capacitor C3 cannot be too large, and it should be ensured that the power of the capacitor C3 is discharged within 0.3 seconds. Among them, in this embodiment, the capacitor C3 is 0.1UF.

[0031] The DRV pin of the power management chip 101 is connected to the resistor R8 and then connected to the G pole of the third MOS transistor 103. The S pole of the third MOS transistor 103 is grounded. The D pole of the third MOS transistor 103 is connected to the LED module 4. When the power management chip 101 outputs the conduction magnitude of the G pole of the third MOS transistor 103 to control the operation of the LED module 4, and then realizes the operation of controlling the LED module 4 with different powers.

[0032] The LED module 4 includes multiple series-connected LEDs 41 and an inductor L1 connected to the LEDs 41. The inductor L1 can effectively filter, thereby preventing crosstalk, and further ensuring that the power management chip can better control the operation of the LED module 4. The inductor L1 is connected to the D pole of the third MOS transistor 103, and the other end of the LED 41 connected to the inductor L1 is connected to the output terminals of the first rectification module 2 and the second rectification module 6 after being connected to a resistor R11.

[0033] The D pole of the third MOS transistor 103 is also connected to the anode of a third diode 109, and the cathode of the third diode 109 is connected to the other end of the resistor R11 connected to the LED 41. The third diode 109 plays a role in protecting the LED 41.

[0034] In summary, the present utility model uses an MCU control chip to control the dimming power of the power management chip, keeping it in a high-power state for 3 seconds, thereby making up for the insufficient power. Subsequently, the power is gradually reduced to suppress the continuous rise of its heat. The high power in the early stage enables the vehicle computer to self-check without faults, enabling the LED headlight to achieve the same power as the original vehicle halogen lamp to meet the usage requirements. At the same time, compared with the resistance decoder, since the circuit is integrated on the PCB board, the present utility model has a smaller volume and requires less installation space, and can be applied to small LED headlights such as turn signal lights, brake lights, and reverse lights. At the same time, the present utility model does not generate a large amount of heat during operation, can reduce the heat generation of the entire LED headlight, ensure the working quality of the LED headlight, and is not likely or even will not cause safety accidents due to the melting of automotive plastic parts or wires, making it safer and more reliable to use.

[0035] Certainly, the above are only specific embodiments of the present utility model and are not intended to limit the scope of implementation of the present utility model. Any equivalent changes or modifications made according to the structure, characteristics, and principles described in the patent application scope of the present utility model should be included within the patent application scope of the present utility model.

Claims

1. A digital circuit decoding circuit for LED car lights, characterized in that: It comprises a low-brightness signal input terminal (1) arranged on a PCB board, a first rectifier module (2), a power management chip (101), a voltage divider module (3), a first MOS tube (102), an LED module (4), a third MOS tube (103), a high-brightness signal input terminal (5), a second rectifier module (6), an MCU control chip (104), and a second MOS tube (105). The low-brightness signal input terminal (1), the first rectifier module (2), and the power management chip (101) are connected in sequence, the voltage divider module (3) is connected between the first rectifier module (2) and the power management chip (101), and the first MOS tube (102) is connected between the low-brightness signal input terminal (1) and the voltage divider module (3) to control the voltage input of the voltage divider module (3) to the dimming pin of the power management chip (101); The highlight signal input end (5), the second rectifier module (6), and the power management chip (101) are connected in sequence; the highlight signal input end (5) is connected to the second MOS tube (105) to control the on and off of the second MOS tube (105); the second MOS tube (105) is also connected between the MCU control chip (104) and the power management chip (101); when the second MOS tube (105) is turned on, the MCU control chip (104) outputs a PWM signal to the power management chip (101) to control the output power of the power management chip (101); The LED module (4) is connected to a first rectifier module (2) and a second rectifier module (6); the power management chip (101) is connected to the LED module (4) via a third MOS tube (103) to output power to control the operation of the LED module (4).

2. The digital circuit decoding circuit for LED vehicle lights according to claim 1, characterized in that: A first voltage stabilizing module (8) is also provided between the first rectifier module (2) and the voltage divider module (3), and the first voltage stabilizing module (8) comprises a first resistor (81) connected to the first rectifier module (2) and a first voltage stabilizing diode (82) connected to the first resistor (81).

3. The digital circuit decoding circuit for LED vehicle lights according to claim 1, characterized in that: The output ends of the first rectifier module (2) and the second rectifier module (6) are connected and are also connected to a filter module (9), the filter module (9) comprising a capacitor C1 and a capacitor C2 connected in parallel with each other, one end of the capacitor C1 being connected to the output ends of the first rectifier module (2) and the second rectifier module (6), and the other end of the capacitor C1 being connected to the ground.

4. The digital circuit decoding circuit for LED vehicle lights according to claim 1, characterized in that: The voltage dividing module (3) comprises a first voltage dividing resistor R13 and a second voltage dividing resistor R14 connected in series, the first voltage dividing resistor R13 is connected to the first resistor (81), the cathode of the first voltage zener diode (82) is connected to the connection line between the first voltage dividing resistor R13 and the first resistor (81), the anode of the first voltage zener diode (82) is grounded, and the second voltage dividing resistor R14 is connected to the first MOS tube (102).

5. The digital circuit decoding circuit for LED vehicle lights according to claim 4, characterized in that: The D pole of the first MOS tube (102) is connected to the second voltage-dividing resistor R14 of the voltage-dividing module (3), the S pole of the first MOS tube (102) is grounded, and the G pole of the first MOS tube (102) is connected to the resistor R5 and the first diode (106) and then connected to the low-brightness signal input terminal (1).

6. A digital circuit decoding circuit for LED vehicle lights according to any one of claims 1 to 5, characterized in that: The D pole of the second MOS tube (105) is connected to the resistor R4 and then to the dimming pin of the power management chip (101); the S pole of the second MOS tube (105) is connected to the DIM pin of the MCU control chip (104); and the G pole of the second MOS tube (105) is connected to the resistor R2 and the second diode (107) and then to the highlight signal input terminal (5).

7. The digital circuit decoding circuit for LED vehicle lights according to claim 6, characterized in that: The resistor R2 is also connected to the VCC pin of the MCU control chip (104), and the resistor R2 is also connected to the second voltage stabilizing diode (108) and then grounded; the VCC pin of the MCU control chip (104) is also connected to a capacitor C3 for charging and then grounded.

8. A digital circuit decoding circuit for LED vehicle lights according to any one of claims 1 to 5, characterized in that: The DRV pin of the power management chip (101) is connected to the resistor R8 and then to the G pole of the third MOS tube (103); the S pole of the third MOS tube (103) is grounded; and the D pole of the third MOS tube (103) is connected to the LED module (4).

9. A digital circuit decoding circuit for LED vehicle lights according to any one of claims 1 to 5, characterized in that: The LED module (4) comprises a plurality of LEDs (41) connected in series and an inductor L1 connected to the LEDs (41); the inductor L1 is connected to the D pole of a third MOS tube (103); the other end of the LED (41) connected to the inductor L1 is connected to a resistor R11 and then connected to the output ends of the first rectifier module (2) and the second rectifier module (6).

10. The digital circuit decoding circuit for LED vehicle lights according to claim 9, characterized in that: The D pole of the third MOS tube (103) is also connected to the anode of the third diode (109), and the cathode of the third diode (109) is connected to the other end of the resistor R11 connected to the LED (41).

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