Circuit for realizing automobile LED matrix control through discrete device

Abstract

The utility model discloses a circuit for realizing automobile LED matrix control through discrete devices, which comprises a discrete matrix switch module, the discrete matrix switch module comprises a plurality of switch circuits, and each switch circuit comprises a D trigger, a triode Q1, a triode Q2, a triode Q3 and an MOS tube M1. According to the automobile LED matrix control circuit, matrix control over automobile LEDs is achieved through the D trigger and common resistors, diodes, capacitors, triodes and MOS tubes, and compared with a matrix chip, the automobile LED matrix control circuit has the great advantages in the aspects of delivery time and cost; according to the utility model, light control with multiple functions can be realized through one high-voltage constant-current drive, and the cost is effectively reduced.

Description

Technical Field

[0001] This utility model belongs to the field of automotive LED matrix control technology, specifically relating to a circuit that realizes automotive LED matrix control through discrete devices. Background Technology

[0002] With the development of automotive technology, the functions of vehicle lights are becoming increasingly diverse. In addition to basic illumination, conventional low beam headlights, high beam headlights, turn signals, daytime running lights, and position lights also need to achieve various lighting effects. This has led to a growing demand for LED matrix control solutions, and consequently, an increasing requirement for the number of LED channels. This has resulted in the following problems:

[0003] 1. The increased demand for channels has led to a significant increase in the number of components, resulting in higher costs.

[0004] 2. For the application of matrix chips, the market currently mainly uses integrated chip solutions, which brings about cost and delivery time issues that have a critical impact on project research and development.

[0005] 3. The number of channels in the matrix solution of integrated chips is fixed, but in practical applications, it is not always possible to fully utilize all matrix channels, resulting in redundant channels and cost overload. Utility Model Content

[0006] The purpose of this invention is to provide a circuit for controlling an automotive LED matrix using discrete components, thereby solving the problems mentioned in the background section. The circuit for controlling an automotive LED matrix using discrete components provided by this invention features low cost and short lead time.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a circuit for controlling an automotive LED matrix using discrete devices, comprising a discrete matrix switch module. The discrete matrix switch module includes several switching circuits, each including a D flip-flop, transistors Q1, Q2, and Q3, and a MOSFET M1. The drain of MOSFET M1 is the DDC_OUTP terminal, the source of MOSFET M1 is the TURNP_OUAT terminal, the gate of MOSFET M1 is connected to one end of resistor R1, and the other end of resistor R1 is connected to the emitter of transistor Q2 and the collector of transistor Q3. The source of MOSFET M1 is connected to the emitter of transistor Q3. The bases of transistors Q2 and Q3 are both connected to one end of resistor R4. The collector of transistor Q2 is connected to one end of resistor R3. The other end of resistor R3 is connected to one end of resistor R2. The connection between resistors R2 and R3 is connected to the constant current output terminal of high-voltage constant current drive 1. The other ends of resistors R2 and R4 are connected to the collector of transistor Q1. The emitter of transistor Q1 is connected to ground. The base of transistor Q1 is connected to one end of resistor R13. The other end of resistor R13 is connected to the NQ pin of the D flip-flop.

[0008] Furthermore, a resistor R5 is connected in parallel across the two ends of resistor R1.

[0009] Furthermore, the gate of MOSFET M1 is connected to one end of resistor R6 and one end of resistor R7, the other end of resistor R6 is connected to the source of MOSFET M1, and the other end of resistor R7 is connected to the drain of MOSFET M1.

[0010] Furthermore, the emitter of transistor Q3 is connected to one end of capacitor C1, and the other end of capacitor C1 is connected to the collector of transistor Q2.

[0011] To prevent transistor Q3 from being overvoltage-damped, the emitter of transistor Q3 is further connected to the positive terminal of diode D2, and the negative terminal of diode D2 is connected to the base of transistor Q3.

[0012] To protect transistors Q2 and Q3, the emitter of transistor Q3 is further connected to the positive terminal of Zener diode D3, the negative terminal of Zener diode D3 is connected to the collector of transistor Q2, the base of transistor Q2 is connected to the positive terminal of diode D1, and the negative terminal of diode D1 is connected to the collector of transistor Q2.

[0013] To determine the LED's operating status and provide feedback to the vehicle body, a transistor Q4 is further included. The emitter of transistor Q4 is connected to one end of resistors R8 and R9, respectively. The other end of resistor R8 is connected to the drain of MOSFET M1. The base of transistor Q4 is connected to one end of resistors R10 and R11, respectively. The other ends of resistors R9 and R10 are both connected to a +5V voltage. The other end of resistor R11 is connected to the source of MOSFET M1. The collector of transistor Q4 is the VO_CORN terminal. The collector of transistor Q4 is connected to one end of resistor R12, and the other end of resistor R12 is connected to ground.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model achieves matrix control of automotive LEDs by using D flip-flops and commonly used resistors, diodes, capacitors, transistors and MOSFETs. Compared with using matrix chips, it has significant advantages in both delivery time and cost.

[0016] 2. This utility model can achieve multiple lighting functions through a single high-voltage constant current drive, effectively reducing costs;

[0017] 3. This utility model clamps the voltage between the base and emitter of transistor Q3 to within 1V using diode D2, which can prevent transistor Q3 from being overvoltage-damaged.

[0018] 4. This utility model uses Zener diode D3 to maintain the voltage between the collector of transistor Q2 and the base of transistor Q3 within a reasonable range, thus protecting transistors Q2 and Q3. At the same time, a diode D1 is connected in parallel to protect transistor Q2.

[0019] 5. This utility model, through the cooperation of transistor Q4 and its peripheral components, enables MCU2 to determine the LED working status by the voltage at the collector terminal of transistor Q4 and to feed back the lighting working status to the vehicle body. Attached Figure Description

[0020] Figure 1 This is a circuit block diagram of the present invention;

[0021] Figure 2 This is a circuit diagram of the switching circuit of this utility model.

[0022] In the diagram: 1. High-voltage constant current drive; 2. MCU; 3. Discrete matrix switch module; 4. Vehicle lighting module. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example 1

[0025] Please see Figures 1-2 This utility model provides the following technical solution: a circuit for controlling an automotive LED matrix using discrete devices, comprising a discrete matrix switch module 3. The discrete matrix switch module 3 includes several switching circuits, each including a D flip-flop, transistors Q1 (NPN type), Q2 (NPN type), Q3 (PNP type), and a MOSFET M1. The drain of MOSFET M1 is the DDC_OUTP terminal, and the source of MOSFET M1 is the TURNP_OUAT terminal. The DDC_OUTP and TURNP_OUAT terminals are connected in parallel to the corresponding functional LEDs. The gate of MOSFET M1 is connected to one end of resistor R1, and the other end of resistor R1 is connected to the emitter of transistor Q2 and the emitter of transistor Q3. The collector is connected, the source of MOSFET M1 is connected to the emitter of transistor Q3, the bases of transistors Q2 and Q3 are both connected to one end of resistor R4, the collector of transistor Q2 is connected to one end of resistor R3, the other end of resistor R3 is connected to one end of resistor R2, resistor R2 provides current limiting protection for transistor Q1, resistor R3 provides current limiting protection for transistors Q2 and Q3, the connection between resistors R2 and R3 is connected to the constant current output terminal of high voltage constant current drive 1, the other ends of resistors R2 and R4 are respectively connected to the collector of transistor Q1, the emitter of transistor Q1 is connected to the ground terminal, the base of transistor Q1 is connected to one end of resistor R13, and the other end of resistor R13 is connected to the NQ pin of D flip-flop.

[0026] By adopting the above technical solution, the present invention realizes automotive LED matrix control through the following steps:

[0027] (1) When the power supply is turned on, the high voltage constant current drive 1 starts to work and prepares to output current. When the light enable signal is received, the MCU2 turns on the corresponding switch circuit in the discrete matrix switch module 3 and controls the output current of the high voltage constant current drive 1 to light up the corresponding function.

[0028] (2) When a function lighting request is received, MCU2 sends a low level to the DATA pin of the D flip-flop, and when the rising edge of CLOCK arrives, it transmits all the DATA pin signals of the D flip-flops to the output NQ terminal. At this time, the NQ terminal is at a high level. When the light needs to be lit, point A (the connection point of resistors R2 and R3, i.e. the output terminal of high voltage constant current drive 1) is activated. At this time, transistor Q1 meets the conduction condition, and point B (the collector of transistor Q1) is pulled down to a low level by transistor Q1. When the LED is lit, since the LED is forward-conducting, the voltage at point C is lower than that at point A. When the LED is off, point C is effectively short-circuited with DDC_OUTP, and the voltage at point C does not exceed that at point A. Since point B is at a low level at this time, transistor Q2 does not meet the conduction condition, while transistor Q3 meets the conduction condition. The gate of MOS transistor M1 is pulled down to a low level (relative to point C) by transistor Q3, so MOS transistor M1 is cut off. At this time, the output current of high voltage constant current drive 1 flows through the LED, thus achieving the goal of lighting the corresponding LED.

[0029] (3) When the corresponding LED needs to be turned off, MCU2 inputs a high level to the DATA pin of the D flip-flop. At this time, the NQ terminal outputs a low level, the base of transistor Q1 is at a low level, so the voltage at point B is pulled up by point A, transistor Q2 is turned on, and transistor Q3 is turned off. At this time, the gate of MOSFET M1 is at a high level, so MOSFET M1 is turned on. The output current of high voltage constant current drive 1 is short-circuited by MOSFET M1 and cannot flow through the parallel LED, thus achieving the purpose of turning off the LED.

[0030] This invention achieves matrix control of automotive LEDs by using D flip-flops and commonly used resistors, diodes, capacitors, transistors, and MOSFETs. Compared with using matrix chips, it has significant advantages in both delivery time and cost. This invention can achieve multiple lighting functions with a single high-voltage constant current driver, effectively reducing costs.

[0031] Specifically, resistor R5 is connected in parallel across resistor R1.

[0032] By adopting the above technical solution, it is easy to adjust the resistance value.

[0033] Specifically, the gate of MOSFET M1 is connected to one end of resistors R6 and R7, the other end of resistor R6 is connected to the source of MOSFET M1, and the other end of resistor R7 is connected to the drain of MOSFET M1.

[0034] By adopting the above technical solution, resistor R6 acts as a pull-down resistor, ensuring that MOSFET M1 does not turn on when the circuit is in an undetermined state, and also serves as an anti-static resistor; resistor R7 provides a discharge circuit for the LED current when the LED is off, ensuring that the LED turns off quickly.

[0035] Specifically, the emitter of transistor Q3 is also connected to one end of capacitor C1, and the other end of capacitor C1 is connected to the collector of transistor Q2.

[0036] By employing the above technical solution for filtering, the impact of voltage fluctuations can be reduced.

[0037] Example 2

[0038] The difference between this embodiment and embodiment 1 is that, specifically, the emitter of transistor Q3 is connected to the positive terminal of diode D2, and the negative terminal of diode D2 is connected to the base of transistor Q3.

[0039] By adopting the above technical solution, the voltage between the base and emitter of transistor Q3 is clamped within 1V by diode D2, which can prevent transistor Q3 from being overvoltage-damped and solve the problem of Vc=(n-1)*V when the LED is lit. D / n, V B When the voltage is low, transistor Q3 will experience excessive reverse voltage.

[0040] Example 3

[0041] The difference between this embodiment and embodiment 1 is that, specifically, the emitter of transistor Q3 is connected to the positive terminal of Zener diode D3, the negative terminal of Zener diode D3 is connected to the collector of transistor Q2, the base of transistor Q2 is connected to the positive terminal of diode D1, and the negative terminal of diode D1 is connected to the collector of transistor Q2.

[0042] By adopting the above technical solution, the voltage between the collector of transistor Q2 and the base of transistor Q3 is maintained within a reasonable range by the Zener diode D3, thus protecting transistors Q2 and Q3. At the same time, due to the presence of the Zener diode D3, the voltage difference between the base and collector of transistor Q2 may be too large, with the base being larger than the collector, which could easily damage transistor Q2. Therefore, a diode D1 is connected in parallel to clamp the voltage to a safe range.

[0043] Example 4

[0044] The difference between this embodiment and Embodiment 1 is that, specifically, it also includes transistor Q4. The emitter of transistor Q4 is connected to one end of resistors R8 and R9, respectively. The other end of resistor R8 is connected to the drain of MOSFET M1. The base of transistor Q4 is connected to one end of resistors R10 and R11, respectively. The other ends of resistors R9 and R10 are both connected to +5V voltage. The other end of resistor R11 is connected to the source of MOSFET M1. The collector of transistor Q4 is the VO_CORN terminal. The collector of transistor Q4 is connected to one end of resistor R12, and the other end of resistor R12 is connected to ground.

[0045] By adopting the above technical solution, when the light is turned on, the voltage across MOSFET M1 is the same as the voltage across the LED. Therefore, the base voltage of transistor Q4 is lower than the emitter voltage, and transistor Q4 is turned on, with the VO_CORN terminal at a high level. When the LED is short-circuited, the base voltage of transistor Q4 is approximately equal to the emitter voltage, and transistor Q4 is turned off, with the VO_CORN terminal at a low level. When the LED is open-circuited, the positive voltage of the faulty LED and the LEDs before it is high, the output state of the VO_CORN terminal remains unchanged, and the positive voltage of the LEDs after the faulty LED is low. The channel that was previously lit and had a high VO_CORN terminal now reports a low VO_CORN terminal. MCU2 can locate the faulty LED through this state change, short-circuit the switch connected in parallel with the LED, and report the fault.

[0046] This invention, through the cooperation of transistor Q4 and its peripheral components, enables MCU2 to determine the LED working status by the voltage at the collector terminal of transistor Q4 and to feed back the lighting working status to the vehicle body.

[0047] In summary, this invention achieves matrix control of automotive LEDs by using D flip-flops and commonly used resistors, diodes, capacitors, transistors, and MOSFETs. Compared to using matrix chips, it offers significant advantages in both delivery time and cost. This invention achieves multiple lighting functions with a single high-voltage constant-current driver, effectively reducing costs. This invention clamps the voltage between the base and emitter of transistor Q3 to within 1V using diode D2, preventing overvoltage breakdown of transistor Q3. This invention maintains the voltage between the collector of transistor Q2 and the base of transistor Q3 within a reasonable range using Zener diode D3, protecting both transistors Q2 and Q3. Simultaneously, a diode D1 in parallel protects transistor Q2. Through the cooperation of transistor Q4 and its peripheral components, MCU2 can determine the LED operating status based on the voltage at the collector of transistor Q4 and provide feedback on the lighting status to the vehicle body.

[0048] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A circuit for controlling an automotive LED matrix using discrete devices, characterized in that: The system includes a discrete matrix switch module, which comprises several switching circuits. These circuits include a D flip-flop, transistors Q1, Q2, and Q3, and a MOSFET M1. The drain of MOSFET M1 is the DDC_OUTP terminal, and its source is the TURNP_OUAT terminal. The gate of MOSFET M1 is connected to one end of resistor R1, and the other end of resistor R1 is connected to the emitter of transistor Q2 and the collector of transistor Q3. The source of MOSFET M1 is connected to the emitter of transistor Q3. The bases of transistors Q2 and Q3 are connected to one end of resistor R4. The collector of transistor Q2 is connected to one end of resistor R3. The other end of resistor R3 is connected to one end of resistor R2. The connection between resistors R2 and R3 is connected to the constant current output terminal of the high voltage constant current drive (1). The other ends of resistors R2 and R4 are connected to the collector of transistor Q1. The emitter of transistor Q1 is connected to the ground terminal. The base of transistor Q1 is connected to one end of resistor R13. The other end of resistor R13 is connected to the NQ pin of the D flip-flop.

2. The circuit for controlling an automotive LED matrix using discrete devices according to claim 1, characterized in that: A resistor R5 is connected in parallel across the two ends of the resistor R1.

3. The circuit for controlling an automotive LED matrix using discrete devices according to claim 1, characterized in that: The gate of the MOS transistor M1 is connected to one end of resistors R6 and R7, respectively. The other end of resistor R6 is connected to the source of the MOS transistor M1, and the other end of resistor R7 is connected to the drain of the MOS transistor M1.

4. The circuit for controlling an automotive LED matrix using discrete devices according to claim 1, characterized in that: The emitter of transistor Q3 is also connected to one end of capacitor C1, and the other end of capacitor C1 is connected to the collector of transistor Q2.

5. The circuit for controlling an automotive LED matrix using discrete devices according to claim 1, characterized in that: The emitter of transistor Q3 is connected to the positive terminal of diode D2, and the negative terminal of diode D2 is connected to the base of transistor Q3.

6. The circuit for controlling an automotive LED matrix using discrete devices according to claim 1, characterized in that: The emitter of transistor Q3 is connected to the positive terminal of Zener diode D3, the negative terminal of Zener diode D3 is connected to the collector of transistor Q2, the base of transistor Q2 is connected to the positive terminal of diode D1, and the negative terminal of diode D1 is connected to the collector of transistor Q2.

7. The circuit for controlling an automotive LED matrix using discrete devices according to claim 1, characterized in that: It also includes transistor Q4. The emitter of transistor Q4 is connected to one end of resistors R8 and R9, respectively. The other end of resistor R8 is connected to the drain of MOSFET M1. The base of transistor Q4 is connected to one end of resistors R10 and R11, respectively. The other ends of resistors R9 and R10 are both connected to +5V voltage. The other end of resistor R11 is connected to the source of MOSFET M1. The collector of transistor Q4 is the VO_CORN terminal.

8. The circuit for controlling an automotive LED matrix using discrete devices according to claim 7, characterized in that: The collector of the transistor Q4 is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the ground terminal.

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