Control circuit for vehicle lamp and vehicle lamp system

Abstract

The invention relates to the technical field of automobile lighting, and discloses a control circuit for an automobile lamp and an automobile lamp system. The signal lamp PWM unit is configured to generate a signal lamp PWM signal according to the signal lamp lightening signal; the constant current control unit is configured to generate an illuminating lamp PWM signal according to the illuminating lamp lightening signal, and control the illuminating lamp and the signal lamp to perform time division multiplexing lightening according to the illuminating lamp PWM signal and the signal lamp PWM signal; wherein the PWM period of the illuminating lamp PWM signal is equal to that of the signal lamp PWM signal, and the high level time of the signal lamp PWM signal is within the low level time of the illuminating lamp PWM signal. The same constant-current control unit is adopted to control the illuminating lamp and the signal lamp, the effect of synchronously lightening the illuminating lamp and the signal lamp visually is achieved through transient visual pause of human eyes, the size of an integrated circuit board is reduced, and the reliability and energy saving performance of the control circuit for the vehicle lamp are greatly improved.

Description

Technical Field

[0001] The present application relates to the field of automobile lighting technology, and in particular to a control circuit and an automobile lighting system for automobile lighting. Background Art

[0002] Headlights are a key factor in ensuring road safety. They not only improve the visibility of vehicles at night or in bad weather conditions, but are also used to communicate the driver's intentions to other road users. During vehicle driving, different types of headlights are usually controlled to light up to meet the needs of different driving scenarios. For example, at night, the driver will turn on the headlights. In extreme weather conditions such as heavy fog, signal lights such as position lights need to be turned on at the same time to indicate the vehicle's position.

[0003] In the related art, lighting lamps and signal lights are generally controlled by independent controllers, which leads to complex hardware design and large size of integrated circuit boards. In addition, signal interference is prone to occur between the two controllers, which affects the control effect of the car lights and reduces the reliability of the car light control system. Summary of the invention

[0004] The present application provides a control circuit and a vehicle light system for vehicle lights, which solve the technical problems that the illumination lamp and the signal lamp are controlled by independent control chips respectively, resulting in a complex control circuit and a large size of the integrated circuit board, and the reliability of the vehicle light control system is not high. The illumination lamp and the signal lamp are lit in a time-sharing multiplexed manner by a constant current control unit combined with a corresponding pulse width modulation (PWM) signal, thereby reducing the size and cost of the control circuit board and improving the reliability of the vehicle light control.

[0005] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0006] In a first aspect, an embodiment of the present application provides a control circuit for a vehicle lamp, the control circuit comprising:

[0007] A lighting lamp driving unit, wherein the lighting lamp driving unit is adapted to receive a lighting lamp lighting signal sent by a vehicle body controller;

[0008] a signal light PWM unit, the signal light PWM unit being configured to generate a signal light PWM signal according to a signal light lighting signal sent by the vehicle body controller;

[0009] A constant current control unit, the constant current control unit is configured to generate a lighting lamp PWM signal according to the lighting lamp lighting signal, and control the lighting lamp and the signal lamp to light up in time-division multiplexing according to the lighting lamp PWM signal and the signal lamp PWM signal;

[0010] The PWM periods of the lighting lamp PWM signal and the signal lamp PWM signal are equal, and the high level time of the signal lamp PWM signal occurs within the low level time of the lighting lamp PWM signal.

[0011] The control circuit proposed in the embodiment of the present application generates corresponding lighting lamp PWM signals and signal lamp PWM signals according to the lighting signals of the lighting lamp and the signal lamp, respectively, and sets the high level time of the signal lamp PWM signal to occur within the low level time of the lighting lamp PWM signal, so as to achieve the effect of using the same constant current control unit to control the lighting of the lighting lamp and the signal lamp alternately, and using the short visual pause of the human eye to achieve the visual effect of lighting the lighting lamp and the signal lamp at the same time. Therefore, compared with the related art, the embodiment of the present application can simultaneously control the time-sharing multiplexing lighting of the lighting lamp and the signal lamp, avoiding the circuit complexity and signal interference caused by the use of multiple independent control chips, not only reducing the size of the integrated circuit board, but also greatly improving the reliability and energy saving of the control circuit for the car lamp.

[0012] Optionally, in some embodiments of the present application, the constant current control unit includes:

[0013] A DC-DC chip, wherein the DC-DC chip is configured to generate a lighting lamp PWM signal according to the lighting lamp lighting signal, and to generate a signal lamp dimming signal according to the signal lamp PWM signal;

[0014] a first MOS transistor, wherein the first MOS transistor is configured to be turned on and off according to the PWM signal of the lighting lamp to generate a dimming signal of the lighting lamp;

[0015] The filtering subcircuit is configured to filter the lighting lamp dimming signal and obtain a lighting lamp constant current power supply signal.

[0016] The embodiment of the present application receives a lighting lamp lighting signal through a DC-DC chip, and converts the lighting lamp lighting signal into a lighting lamp PWM signal through the DC-DC chip, and then drives the conduction and shutdown of the first MOS tube through the lighting lamp PWM signal to control the duty cycle of the lighting lamp dimming signal, and processes the lighting lamp dimming signal into a constant current power supply signal corresponding to the duty cycle through a filtering sub-circuit, thereby ensuring the constant current lighting effect of the lighting lamp.

[0017] Optionally, in some embodiments of the present application, the input end of the DC-DC chip is connected to the first output end of the lighting lamp driving unit via a first resistor, the enable end of the DC-DC chip is connected to the input end of the DC-DC chip via a second resistor, the first output end of the DC-DC chip is connected to the gate of the first MOS tube via a third resistor, the second output end of the DC-DC chip is suitable for outputting the signal lamp dimming signal, the source of the first MOS tube is grounded via a fourth resistor, and the drain of the first MOS tube is suitable for outputting the lighting lamp dimming signal.

[0018] Optionally, in some embodiments of the present application, the control circuit further includes a linkage unit, which is configured to trigger the signal light PWM unit to send the signal light PWM signal to the constant current control unit when the lighting light PWM signal is at a low level.

[0019] The embodiment of the present application detects the situation where the PWM signal of the lighting lamp is at a low level through the linkage unit, and can then trigger the signal lamp PWM unit to drive the signal lamp to light up when the lighting lamp is turned off. Therefore, a single chip can be used to automatically control the time-sharing multiplexing lighting of the lighting lamp and the signal lamp, thereby reducing the complexity of the control circuit and improving the reliability and energy saving of the control circuit.

[0020] Optionally, in some embodiments of the present application, the linkage unit includes:

[0021] a fifth resistor, a first end of the fifth resistor being connected to the second output end of the lighting lamp driving unit;

[0022] A first transistor, wherein a collector of the first transistor is connected to the second end of the fifth resistor and has a first connection node, and an emitter of the first transistor is grounded;

[0023] a first diode, wherein an anode of the first diode is connected to the first connection node, and a cathode of the first diode is connected to a trigger end of the signal light PWM unit;

[0024] a first capacitor, wherein a first end of the first capacitor is connected to a base of the first transistor, and a second end of the first capacitor is connected to an emitter of the first transistor;

[0025] a sixth resistor, wherein a first end of the sixth resistor is connected to the base of the first transistor, and a second end of the sixth resistor is connected to the emitter of the first transistor;

[0026] A seventh resistor, wherein a first end of the seventh resistor is connected to the base of the first transistor, and a second end of the seventh resistor is suitable for receiving a lighting lamp PWM signal.

[0027] Optionally, in some embodiments of the present application, the signal light PWM unit includes:

[0028] a PWM generator, the PWM generator being configured to generate the signal light PWM signal according to the signal light lighting signal sent by the vehicle body controller, wherein an input end of the PWM generator is suitable for receiving the signal light lighting signal;

[0029] a second diode, wherein an anode of the second diode is connected to an output terminal of the PWM generator, and a cathode of the second diode is connected to an enable terminal of the DC-DC chip;

[0030] a third diode, wherein the cathode of the third diode is connected to the triggering end of the PWM generator, and the anode of the third diode is configured as the triggering end of the signal light PWM unit;

[0031] a fourth diode, wherein an anode of the fourth diode is connected to the anode of the third diode, and a cathode of the fourth diode is connected to the second output end of the lighting lamp driving unit;

[0032] A second MOS tube, wherein a gate of the second MOS tube is connected to a second output end of the DC-DC chip via an eighth resistor, a source of the second MOS tube is grounded, and a drain of the second MOS tube is connected to the signal lamp.

[0033] The embodiment of the present application is connected to the linkage unit via the trigger end of the PWM generator, which can trigger the signal light PWM unit to drive the signal light to light up when the lighting light is turned off, thereby realizing time-sharing multiplexing lighting of the lighting light and the signal light under the control of a single chip, reducing circuit complexity and hardware cost.

[0034] Optionally, in some embodiments of the present application, the signal light includes at least one of a turn signal light, a position light and a daytime running light.

[0035] Optionally, in some embodiments of the present application, the lighting lamp includes a low beam lamp and a high beam lamp, and the lighting lamp driving unit includes:

[0036] A low beam input terminal, the low beam input terminal being adapted to receive a low beam lighting signal;

[0037] A high beam input terminal, the high beam input terminal being adapted to receive a high beam lighting signal;

[0038] A high and low beam switching subcircuit, the high and low beam switching subcircuit comprising a third MOS tube, wherein the high and low beam switching subcircuit is configured to, when receiving the low beam lighting signal and not receiving the high beam lighting signal, turn on the third MOS tube to short-circuit the high beam, and when receiving both the low beam lighting signal and the high beam lighting signal, turn off the third MOS tube to connect the high beam and the low beam in series.

[0039] The embodiment of the present application utilizes a high and low beam switching sub-circuit to achieve flexible control of the low beam and the high beam, and controls the short circuit of the high beam by the third MOS tube, so that it can quickly switch between the two vehicle light lighting modes of lighting the low beam alone and lighting the low beam and the high beam at the same time, thereby improving the flexibility and switching speed of the high and low beam switching, and there is no need to additionally set up a controller and its peripheral circuits to separately control the low beam and the high beam, which greatly simplifies the complexity of the circuit structure and reduces the hardware cost.

[0040] Optionally, in some embodiments of the present application, the high and low beam switching subcircuit further includes:

[0041] a second triode, wherein the base of the second triode is connected to the gate and source of the third MOS tube via a second capacitor, the emitter of the second triode is grounded, the collector of the second triode is suitable for connecting to the low beam input terminal, and the collector of the second triode is connected to the gate of the third MOS tube via a ninth resistor;

[0042] a third triode, wherein the base of the third triode is suitable for connecting to the high beam input terminal, the emitter of the third triode is grounded, and the collector of the third triode is suitable for connecting to the low beam input terminal;

[0043] A fourth MOS tube, wherein the gate of the fourth MOS tube is connected to the collector of the third triode via a tenth resistor, the drain of the fourth MOS tube is connected to the gate and source of the third MOS tube, and the source of the fourth MOS tube is grounded.

[0044] In a second aspect, an embodiment of the present application provides a vehicle lamp system, the vehicle lamp system comprising:

[0045] lighting;

[0046] signal light;

[0047] According to the control circuit described in the above embodiment, the control circuit is configured to perform time-division multiplexing control on the lighting lamp and the signal lamp.

[0048] The vehicle light system proposed in the embodiment of the present application uses a control circuit to control the lighting lamp and the signal lamp to light up alternately, and uses the short visual pause of the human eye to achieve the effect of lighting the lighting lamp and the signal lamp at the same time visually. Therefore, compared with the related art, the embodiment of the present application can control the lighting of the lighting lamp and the signal lamp in time-sharing multiplexing, avoiding the circuit complexity and signal interference caused by using multiple independent control chips, not only reducing the size of the integrated circuit board, but also greatly improving the reliability and energy saving of the control circuit for the vehicle light. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 This is a schematic diagram of the structure of a control circuit for a vehicle light proposed in an embodiment of the present application;

[0051] Figure 2 Schematic diagram of the waveform of the PWM signal in the embodiment of the present application;

[0052] Figure 3 A circuit diagram of a constant current control unit proposed in an embodiment of the present application;

[0053] Figure 4 A circuit diagram of a linkage unit proposed in an embodiment of the present application;

[0054] Figure 5 A circuit diagram of a signal light PWM unit proposed in an embodiment of the present application;

[0055] Figure 6 A schematic diagram of an LED circuit of a signal light proposed in an embodiment of the present application;

[0056] Figure 7 A schematic diagram of a high and low beam switching sub-circuit proposed in an embodiment of the present application;

[0057] Figure 8 A circuit diagram of an input protection unit proposed in an embodiment of the present application. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0059] Headlights are a key factor in ensuring road safety. They not only improve the visibility of vehicles at night or in bad weather conditions, but are also used to communicate the driver's intentions to other road users. During vehicle driving, different types of headlights are usually controlled to light up to meet the needs of different driving scenarios. For example, at night, the driver will turn on the headlights. In extreme weather conditions such as heavy fog, signal lights such as position lights need to be turned on at the same time to indicate the vehicle's position.

[0060] In the related art, two controllers and corresponding peripheral circuits are generally used to control the lighting and signal lights respectively, and the control and switching of the lights are completed by multiple independent divisions of labor. However, in some application scenarios of the headlight control system, since signal lights such as turn signals, position lights and daytime running lights are generally used to indicate that the vehicle is about to turn, change lanes or display the outline of the vehicle, compared with the working mode of the lighting that usually maintains long-term lighting, the signal lights are briefly lit under specific driving needs. Therefore, the lighting and signal lights are controlled by different controllers separately, which will occupy too many hardware resources, resulting in complex hardware design and large size of integrated circuit boards, and multiple controllers are prone to signal interference with each other. In addition, the controller used to control the signal light and its peripheral circuits usually use a delay circuit composed of resistors and capacitors to switch and delay between the turn signals, position lights and daytime running lights, which are easily affected by the high and low temperature environment and electromagnetic compatibility outdoors, resulting in a failure to switch smoothly, thereby reducing the reliability of the headlight control system.

[0061] In an embodiment of the present application, a control circuit 10 for a vehicle lamp is provided, such as Figure 1 As shown, the control circuit 10 can be used in a lighting system that integrates a high and low beam lamp with a turn signal lamp, a position lamp, a daytime running lamp and other signal lamps of a vehicle. The control circuit 10 includes a lighting lamp driving unit 100, a signal lamp PWM unit 200 and a constant current control unit 300;

[0062] The lighting lamp driving unit 100 is adapted to receive a lighting lamp lighting signal sent by the vehicle body controller 40;

[0063] The signal light PWM unit 200 is configured to generate a signal light PWM signal according to a signal light lighting signal sent by the vehicle body controller 40;

[0064] The constant current control unit 300 is configured to generate a lighting lamp PWM signal according to the filtered lighting lamp lighting signal, and control the lighting lamp 20 and the signal lamp 30 to light up in time-division multiplexing according to the lighting lamp PWM signal and the signal lamp PWM signal;

[0065] The PWM periods of the lighting lamp PWM signal and the signal lamp PWM signal are equal, and the high level time of the signal lamp PWM signal occurs within the low level time of the lighting lamp PWM signal.

[0066] The embodiment of the present application uses a body controller 40 (Body Control Module, BCM) to supply power and control the lighting lamp 20 and the signal lamp 30 respectively according to the working condition, power state, and switch state of the vehicle. Specifically, the driver can drive the body controller 40 to generate a lighting signal and send it to the corresponding input port by turning the lighting lamp and signal lamp levers on both sides of the steering wheel of the car.

[0067] In the embodiment of the present application, the vehicle body controller 40 supplies power to the lighting lamp 20 and the signal lamp 30 in the following ways: supplying power to the lighting lamp 20 alone, supplying power to the signal lamp 30 alone, and supplying power to both the lighting lamp 20 and the signal lamp 30 at the same time.

[0068] When the vehicle body controller 40 sends out a lighting light signal and a signal light signal at the same time, in order to satisfy the function of using a single chip to control the lighting of the lighting light and the signal light, the embodiment of the present application adopts a PWM time-sharing signal modulation method to light the signal light when the lighting light is turned off, and cooperates with a certain PWM cycle to utilize the brief visual pause of the human eye to achieve the effect of visually lighting the lighting light and the signal light at the same time.

[0069] In some embodiments of the present application, the lighting lamp 20 includes a low beam lamp and a high beam lamp, and the signal lamp 30 includes at least one of a position lamp and a daytime running lamp. Taking the low beam lamp, the position lamp, the turn signal lamp and the daytime running lamp as examples, Figure 2 The signal waveforms of the lighting lamp PWM signal and the signal lamp PWM signal are shown, wherein the duty cycle of the low beam PWM signal is D 近 =T ON(近) / (T ON(近) +T OFF(近) ), the duty cycle of the position light PWM signal is D 位 =T ON(位) / (T ON(位) +T OFF(位) ), the duty cycle of the turn signal PWM signal is D 转 =T ON(转) / (T ON(位) +T OFF(转) ), the duty cycle of the daytime running light PWM signal is D 日 =T ON(日) / (TON(日) +T OFF(日) ), the waveform and duty cycle of the high beam PWM signal are the same as those of the low beam PWM signal, and the position lights, turn signals and daytime running lights are all at the time when the low beam or high beam is turned off, that is, T OFF(近) on and off during the specified time period.

[0070] The above duty cycle is determined according to the working current of the lighting lamp and the signal lamp. For example, the average current of the lighting lamp is set to 1A, the peak current of the lighting lamp is set to 1.5A, the current of the position lamp is set to 0.05A, the current of the turn signal lamp is set to 0.1A, and the current of the daytime running lamp is set to 0.12A. On this basis, the duty cycle of the low beam is set to 66%, the duty cycle of the position lamp is set to 3.3%, the duty cycle of the turn signal lamp is set to 6.6%, and the duty cycle of the daytime running lamp is set to 8%. At the same time, in order to take advantage of the short visual pause of the human eye to ensure that the moment when the lighting lamp and the signal lamp are not lit cannot be recognized by the naked eye, the lighting cycle of the low beam, high beam, position lamp, turn signal, and daytime running lamp is 50ms.

[0071] Therefore, the control circuit provided in this embodiment generates corresponding lighting lamp PWM signals and signal lamp PWM signals according to the lighting signals of the lighting lamp and the signal lamp, respectively, and sets the high level time of the signal lamp PWM signal to occur within the low level time of the lighting lamp PWM signal, so as to achieve the effect of using the same constant current control unit 300 to control the lighting of the lighting lamp 20 and the signal lamp 30 alternately, and using the short visual pause of the human eye to achieve the visual effect of lighting the lighting lamp and the signal lamp at the same time. Therefore, compared with the related art, the embodiment of the present application can simultaneously control the time-sharing multiplexing lighting of the lighting lamp 20 and the signal lamp 30, avoids the circuit complexity and signal interference caused by using multiple independent control chips, not only reduces the size of the integrated circuit board, but also greatly improves the reliability and energy saving of the control circuit 10 for vehicle lights.

[0072] In some embodiments of the present application, Figure 3 As shown, the constant current control unit 300 includes a DC-DC chip U3, a first MOS transistor Q1 and a filter sub-circuit 310;

[0073] The DC-DC chip U3 is configured to generate a lighting lamp PWM signal according to the lighting lamp lighting signal, and to generate a signal lamp dimming signal according to the signal lamp PWM signal;

[0074] The first MOS tube Q1 is configured to be turned on and off according to the PWM signal of the lighting lamp to generate a dimming signal of the lighting lamp;

[0075] The filtering subcircuit 310 is configured to filter the lighting lamp dimming signal and obtain a lighting lamp constant current power supply signal.

[0076] The DC-DC chip is an integrated circuit for voltage conversion. The DC-DC chip U3 in the embodiment of the present application adopts PWM modulation mode, and realizes the conversion of the DC power supply level by continuously turning on and off the high-speed switch and controlling the duty cycle of the switch. Therefore, in the embodiment of the present application, the DC-DC chip U3 receives the lighting signal of the lighting lamp, converts the power supply voltage of the vehicle body controller 40 to the lighting lamp 20 into the lighting lamp PWM signal that meets the above-mentioned duty cycle setting, and controls the on and off of the first MOS tube Q1 according to the lighting lamp PWM signal. If the lighting lamp PWM signal is at a high level, the first MOS tube Q1 is turned on, and if the lighting lamp PWM signal is at a low level, the first MOS tube Q1 is turned off. Then, the lighting lamp dimming signal output by the drain of the first MOS tube Q1 is filtered by the filtering subcircuit to obtain the lighting lamp constant current power signal.

[0077] Therefore, the embodiment of the present application receives the lighting signal of the lighting lamp through the DC-DC chip, and converts the lighting signal of the lighting lamp into a lighting lamp PWM signal through the DC-DC chip, and then drives the conduction and shutdown of the first MOS tube through the lighting lamp PWM signal to control the duty cycle of the lighting lamp dimming signal, and processes the lighting lamp dimming signal into a constant current power supply signal corresponding to the duty cycle through the filtering sub-circuit, thereby ensuring the constant current lighting effect of the lighting lamp.

[0078] Specifically, if Figure 3 As shown, the input end of the DC-DC chip U3 is connected to the first output end TP1 of the lighting lamp driving unit 100 via the first resistor R51, the enable end of the DC-DC chip U3 is connected to the input end of the DC-DC chip U3 via the second resistor R16, the first output end GATE of the DC-DC chip U3 is connected to the gate of the first MOS tube Q1 via the third resistor R6, the second output end PWMOUT of the DC-DC chip U3 is suitable for outputting the above-mentioned signal lamp dimming signal, the source of the first MOS tube Q1 is grounded via the fourth resistor R24, and the drain of the first MOS tube Q1 is suitable for outputting the above-mentioned lighting lamp dimming signal.

[0079] The filter subcircuit 310 includes: an input end of a voltage regulator D6 connected to a drain of a first MOS tube Q1, an output end of the voltage regulator D6 connected to a first end of a capacitor C22, and a capacitor C15 and a resistor R10 are first connected in series and then connected in parallel at both ends of the voltage regulator D6, and the first ends of capacitors C22, capacitors C16, capacitors C17, capacitors C18, capacitors C10, capacitors C7, and capacitors C8 are connected and the second ends are all grounded; a first end of a resistor R8 is connected to a connection node between capacitors C10 and capacitor C7, a second end of the resistor R8 is connected to a resistor R12 and has a second connection node, and a capacitor C23 is connected in parallel to both ends of the resistor R8 and connected through the second connection node. The OUV end of the DC-DC chip U3 is connected to the OUV end of the DC-DC chip U3 to realize overvoltage protection of the DC-DC chip U3; the first ends of the capacitors C8 and C19 are connected and the second ends are both grounded, the resistor R2 is connected in series between the first end of the capacitor C8 and the first end of the capacitor C19, and the resistor R5 is connected in parallel across the resistor R2, and the two ends of the resistor R2 are respectively connected to the VSP end and the VSN end of the DC-DC chip U3 through the resistor R76 and the resistor R77 to realize the feedback loop of the constant current power supply signal of the lighting lamp; the inductor L1 is connected in series between the first end of the capacitor C19 and the first end of the capacitor C69, the first end of the capacitor C69 is connected to the first end of the capacitor C1 and the second ends are both grounded.

[0080] The dimming signal of the lighting lamp is sent to the filtering sub-circuit 310 via the voltage regulator D6, and after filtering, a constant current power signal of the lighting lamp is output from a node VLED+ set at the first end of the capacitor C1.

[0081] Specifically, when it is necessary to light up the low beam lamp separately, the LB terminal receives a low beam lamp lighting signal of 9-16V, and is sent to the VIN pin of the DC-DC chip U3 after passing through the input protection subcircuit, the anti-reverse connection subcircuit, the input overvoltage protection subcircuit and the input filter subcircuit, and is stored through the inductor L6 after passing through the input filter subcircuit. In the embodiment of the present application, a boost topology architecture is adopted, and the inductor L6 stores and releases energy according to the number and voltage of the load LEDs. The energy storage and release of the energy storage inductor L6 are controlled by the first MOS tube Q1 in the constant current control unit 300. When the first MOS tube Q1 is turned on, the inductor L6 stores energy, and when the first MOS tube Q1 is turned off, the inductor L6 releases energy. At the same time, the gate signal of the first MOS tube Q1 is provided by the lighting lamp PWM signal output by the GATE pin of the DC-DC chip U3, thereby outputting the lighting lamp dimming signal through the drain of the first MOS tube Q1.

[0082] In some embodiments of the present application, the control circuit 10 further includes a linkage unit 400 , which is configured to trigger the signal light PWM unit 200 to send the signal light PWM signal to the constant current control unit 300 when the lighting light PWM signal is at a low level.

[0083] Therefore, the embodiment of the present application detects the situation where the lighting lamp PWM signal is at a low level through the linkage unit, and can then trigger the signal lamp PWM unit 200 to drive the signal lamp to light up when the lighting lamp is turned off. Therefore, a single chip can be used to automatically control the time-sharing multiplexing lighting of the lighting lamp and the signal lamp, thereby reducing the complexity of the control circuit and improving the reliability and energy saving of the control circuit.

[0084] Furthermore, if Figure 4 As shown, the linkage unit 400 includes a fifth resistor R97, a first transistor Q15, a first diode D30, a first capacitor C85, a sixth resistor R95 and a seventh resistor R96, wherein a first end of the fifth resistor R97 is connected to the second output end TP2 of the lighting lamp driving unit 100, a collector of the first transistor Q15 is connected to the second end of the fifth resistor R97 and has a first connection node, an emitter of the first transistor Q15 is grounded, an anode of the first diode D30 is connected to the first connection node, and the first diode The cathode of D30 is connected to the trigger end of the signal light PWM unit 200, the first end of the first capacitor C85 is connected to the base of the first transistor Q15, the second end of the first capacitor C85 is connected to the emitter of the first transistor Q15, the first end of the sixth resistor R95 is connected to the base of the first transistor Q15, the second end of the sixth resistor R95 is connected to the emitter of the first transistor Q15, the first end of the seventh resistor R96 is connected to the base of the first transistor Q15, and the second end of the seventh resistor R96 is suitable for receiving the lighting light PWM signal.

[0085] In some embodiments of the present application, Figure 5 As shown, the signal light PWM unit 200 includes a PWM generator U1, a second diode D15, a third diode D29, a fourth diode D18 and a second MOS tube Q8, wherein the PWM generator 210 is configured to generate a signal light PWM signal according to a signal light lighting signal sent by the vehicle body controller 40, the input end of the PWM generator 210 is suitable for receiving the signal light lighting signal, the anode of the second diode D15 is connected to the output end of the PWM generator 210, the cathode of the second diode D15 is connected to the enable end of the DC-DC chip U3, and the third The cathode of the diode D29 is connected to the trigger end of the PWM generator 210, the anode of the third diode D29 is configured as the trigger end of the signal light PWM unit 200, the anode of the fourth diode D18 is connected to the anode of the third diode D29, the cathode of the fourth diode D18 is connected to the second output end TP2 of the lighting lamp driving unit 100, the gate of the second MOS tube Q8 is connected to the second output end PWMOUT of the DC-DC chip U3 via the eighth resistor R88, the source of the second MOS tube Q8 is grounded, and the drain of the second MOS tube Q8 is connected to the signal light 30.

[0086] The embodiment of the present application is connected to the linkage unit via the trigger end of the PWM generator, and can trigger the signal light PWM unit 200 to drive the signal light to light up when the lighting light is turned off, thereby realizing time-sharing multiplexing of the lighting light and the signal light under the control of a single chip, reducing circuit complexity and hardware cost.

[0087] It should be noted that in some embodiments of the present application, the signal light includes at least one of a turn signal light, a position light, and a daytime running light. Figure 5 The signal light PWM units 200 corresponding to the turn signal, position light and daytime running light are also shown and connected in parallel with each other, wherein the daytime running light lighting signal is input through the DRL terminal and passes through the corresponding input protection sub-circuit to absorb surge voltage, static electricity and lightning surge, and then the daytime running light lighting signal is sent to the VCC pin of the PWM generator U1, and the corresponding daytime running light PWM signal is output at the output pin of the PWM generator U1, and then the daytime running light PWM signal is sent to the EN pin of the DC-DC chip U3 through the second diode D15, and the VCC pin of the PWM generator U2 is connected to the second output terminal TP2 of the lighting lamp driving unit 100 through the fourth diode D18 to power the PWM generator U1. Similarly, the position light lighting signal is input through the PL terminal, and passes through the corresponding input protection sub-circuit to absorb surge voltage, static electricity and lightning surge, and then the position light lighting signal is sent to the VCC pin of the PWM generator U2, and the corresponding position light PWM signal is output at the output pin of the PWM generator U2, and then the daytime running light PWM signal is sent to the EN pin of the DC-DC chip U3 through the second diode D16, and the VCC pin of the PWM generator U3 is connected to the second output terminal TP2 of the lighting lamp driving unit 100 through the fourth diode D19 to power the PWM generator U2. The turn signal lighting signal is input through the TL terminal, and passes through the corresponding input protection sub-circuit to absorb surge voltage, static electricity and lightning surge, and then the turn signal lighting signal is sent to the VCC pin of the PWM generator U5, and the corresponding turn signal PWM signal is output at the output pin of the PWM generator U5, and then the turn signal PWM signal is sent to the EN pin of the DC-DC chip U3 through the second diode D17, and the VCC pin of the PWM generator U5 is connected to the second output terminal TP2 of the lighting lamp driving unit 100 through the fourth diode D20 to power the PWM generator U5.

[0088] In some embodiments of the present application, the signal light is only lit when the lighting lamp is turned off, that is, the high level time of the signal light PWM signal occurs during the low level time of the lighting lamp PWM signal. Therefore, when the GATE pin of the DC-DC chip U3 outputs a low level, the base of the first transistor Q15 is at a low level, so the first transistor Q15 is not turned on. At this time, the Trig pin of the PWM generator U1, the Trig pin of the PWM generator U2, and the Trig pin of the PWM generator U5 are at a high level, thereby triggering the PWM generator U1, the PWM generator U2, and the PWM generator U5 to normally generate the corresponding signal light PWM signal. At the same time, the output pins of the PWM generator U1, the PWM generator U2, and the PWM generator U5 are connected to the EN pin of the DC-DC chip U3, so that the generated signal light PWM signal is used to enable the DC-DC chip U3 to output the signal light dimming signal through the PWMOUT pin as the second output terminal, and send the signal light dimming signal to the gate of the second MOS tube Q8.

[0089] Further, Figure 6 The LED circuit of the signal light in some embodiments of the present application is shown, wherein WLED1-WLED36 is a multiplexed LED for the daytime running light and the position light, YLED1-YLED36 is an LED for the turn signal light, and the cathode of the LED matrix composed of WLED1-WLED36 is connected to the daytime running light / position light switch circuit, and the cathode of the LED matrix composed of YLED1-YLED36 is connected to the turn signal light switch circuit. Specifically, the drain of the MOS tube Q7 in the daytime running light / position light switch circuit is connected to the cathode of the LED matrix composed of WLED1-WLED36, the source of the MOS tube Q7 is connected to the drain of the second MOS tube Q8 in the signal light PWM unit 200, the gate of the MOS tube Q7 is connected to the DRL terminal and the PL terminal via the resistor R90, and an input protection subcircuit is provided between the resistor R90 and the gate of the MOS tube Q7 to absorb surge voltage, static electricity and lightning surge. The drain of the MOS tube Q9 in the turn signal switch circuit is connected to the cathode of the LED matrix composed of YLED1-YLED36, the source of the MOS tube Q9 is connected to the drain of the second MOS tube Q8 in the signal light PWM unit 200, the gate of the MOS tube Q9 is connected to the TL terminal via the resistor R92, and an input protection subcircuit is also provided between the resistor R902 and the gate of the MOS tube Q9 to absorb surge voltage, static electricity and lightning surge.

[0090] The gate of the second MOS tube Q8 is turned on when receiving a high-level signal light dimming signal, and combined with the reception of the signal light lighting signals at the DRL, PL and TL terminals, the corresponding MOS tubes Q7 and Q9 are turned on, and finally the corresponding daytime running light LED, position light LED and turn signal light LED are turned on and lit normally.

[0091] When the lighting lamp PWM signal outputted by the gate pin of the DC-DC chip U3 is at a high level, the base of the transistor Q15 is at a high level, so the first transistor Q15 is turned on, and at this time, the Trig pins of the PWM generator U1, the Trig pins of the PWM generator U2, and the Trig pins of the PWM generator U5 are at a low level, thereby triggering the PWM generators U1, U2, and U5 to stop generating the corresponding signal lamp PWM signal. At the same time, the output pins of the PWM generators U1, U2, and U5 are connected to the EN pin of the DC-DC chip U3, so the enable end EN of the DC-DC chip U3 is always at a low level, and the PWMOUT pin as the second output end will not output the signal lamp dimming signal, thereby turning off the second MOS tube Q8, and the MOS tubes Q7 and Q9, and finally making the daytime running light LED, position light LED, and turn signal LED non-conductive and unable to light up.

[0092] In some embodiments of the present application, the lighting lamp 20 includes a low beam lamp and a high beam lamp, and the lighting lamp driving unit 100 includes:

[0093] A low beam input terminal LB, the low beam input terminal is suitable for receiving a low beam lighting signal;

[0094] A high beam input terminal HB, the high beam input terminal is suitable for receiving a high beam lighting signal;

[0095] The high and low beam switching sub-circuit includes a third MOS tube Q4, wherein the high and low beam switching sub-circuit is configured to turn on the third MOS tube Q4 to short-circuit the high beam when a low beam lighting signal is received but a high beam lighting signal is not received, and to turn off the third MOS tube Q4 to connect the high beam and the low beam in series when both the low beam lighting signal and the high beam lighting signal are received.

[0096] Furthermore, if Figure 7 As shown, the high and low beam switching sub-circuit also includes:

[0097] a second triode Q5, wherein the base of the second triode Q5 is connected to the gate and source of the third MOS tube Q4 via the second capacitor C13, the emitter of the second triode Q5 is grounded, the collector of the second triode Q5 is suitable for connecting to the low beam input terminal, and the collector of the second triode Q5 is connected to the gate of the third MOS tube Q4 via the ninth resistor R14;

[0098] a third transistor Q6, wherein the base of the third transistor Q6 is suitable for being connected to the high-beam input terminal, the emitter of the third transistor Q6 is grounded, and the collector of the third transistor Q6 is suitable for being connected to the low-beam input terminal;

[0099] The gate of the fourth MOS transistor Q3 is connected to the collector of the third triode Q6 via the tenth resistor R53, the drain of the fourth MOS transistor Q3 is connected to the gate and source of the third MOS transistor Q4, and the source of the fourth MOS transistor Q3 is grounded.

[0100] The embodiment of the present application utilizes a high-beam switching subcircuit to achieve flexible control of the low beam and the high beam, and controls the short circuit of the high beam by the third MOS tube Q4, so that it can quickly switch between the two vehicle light lighting modes of lighting the low beam alone and lighting the low beam and the high beam at the same time, thereby improving the flexibility and switching speed of the high-beam switching, and there is no need to additionally set up a controller and its peripheral circuits to separately control the low beam and the high beam, which greatly simplifies the complexity of the circuit structure and reduces the hardware cost.

[0101] like Figure 8 As shown, in some embodiments of the present application, an input protection unit consisting of an input protection subcircuit, an anti-reverse connection subcircuit, an input overvoltage protection subcircuit and an input filtering subcircuit is further provided between the low beam input terminal LB and the DC-DC chip U3.

[0102] The input protection subcircuit includes a transient voltage suppression diode TVS2, a capacitor C14 and a resistor R4, and receives a low beam lighting signal from the vehicle body controller 40 through the LB terminal to absorb surge voltage, static electricity and lightning surge.

[0103] The anti-reverse connection sub-circuit includes a MOS transistor Q18, a resistor R73, a resistor R74 and a voltage stabilizing diode D34, and is used for performing anti-reverse connection protection through the MOS transistor Q18, and using the drain of the MOS transistor Q18 as the second output terminal TP2 of the lighting lamp driving unit 100.

[0104] The input overvoltage protection subcircuit includes a resistor R60, a resistor R61, a resistor R62, a three-terminal regulator U4, a MOS transistor Q13, a MOS transistor Q2 and peripheral circuits thereof. In some embodiments of the present application, when the voltage of the low beam lighting signal input at the LB terminal is greater than 24V, the voltage is divided by resistors R60 and R61 and compared with the 2.5V reference voltage of the three-terminal regulator U4. At this time, the voltage after voltage division is greater than the reference voltage, so the three-terminal regulator U4 outputs a low level, so that the gate voltage of the MOS transistor Q13 is low and cut off. Since the MOS transistor Q13 is cut off, the gate of the MOS transistor Q2 is high, causing the MOS transistor Q2 to be cut off, and ultimately making it impossible for the low beam lighting signal to be sent to the DC-DC chip U3, thereby protecting the entire circuit from damage due to overvoltage. When the input voltage does not exceed 24V, the voltage is divided by resistors R60 and R61 and compared with the 2.5V reference voltage of the three-terminal regulator U4. At this time, since the voltage after voltage division is less than the reference voltage 2.5V, the three-terminal regulator U4 outputs a high level, so that the gate voltage of the MOS tube Q13 is high and turned on. Since the MOS tube Q13 is turned on, the gate of the MOS tube Q2 is low, causing the MOS tube Q2 to be turned on, and finally the low beam lighting signal can be normally sent to the DC-DC chip U3, thereby ensuring the normal operation of the entire control circuit 10.

[0105] The input filter subcircuit includes an inductor L2, a capacitor C11, a capacitor C2, a capacitor C3, a capacitor C4 and a capacitor C9. The input filter subcircuit forms a π-shaped filter through the inductor L2, the capacitor C11, the capacitor C2, the capacitor C3, the capacitor C4 and the capacitor C9 to filter out various high and low frequency interference sources and ensure that the voltage flowing through the DC-DC chip U3 is a stable voltage. Preferably, the capacitors of the π-shaped filter are combined with nF level and uF level capacitors. In order to reduce the influence of the anti-resonance frequency point, the capacitance values ​​of the capacitors differ by more than 100 times. In addition, the connection node between the capacitor C9 and the inductor L6 is used as the first output terminal TP1 of the lighting lamp driving unit 100.

[0106] Specifically, when it is necessary to light up the low beam lamp separately, the LB terminal receives a low beam lamp lighting signal of 9-16V, and is sent to the VIN pin of the DC-DC chip U3 after passing through the input protection subcircuit, the anti-reverse connection subcircuit, the input overvoltage protection subcircuit and the input filter subcircuit, and is stored through the inductor L6 after passing through the input filter subcircuit. In the embodiment of the present application, a boost topology architecture is adopted, and the inductor L6 stores and releases energy according to the number and voltage of the load LEDs. The energy storage and release of the energy storage inductor L6 are controlled by the first MOS tube Q1 in the constant current control unit 300. When the first MOS tube Q1 is turned on, the inductor L6 stores energy, and when the first MOS tube Q1 is turned off, the inductor L6 releases energy. At the same time, the gate signal of the first MOS tube Q1 is provided by the lighting lamp PWM signal output by the GATE pin of the DC-DC chip U3, thereby outputting the lighting lamp dimming signal through the drain of the first MOS tube Q1.

[0107] In the embodiments of the present application, Figure 7 The diagram shows a low beam lamp composed of LED1 to LED8 connected in series, and a high beam lamp composed of LED9 to LED13 connected in series.

[0108] At the same time, the low beam lighting signal received by the LB end is sent to the gate of the third MOS tube Q4 through the anti-reverse connection diode D7, the resistor R13 and the resistor R14, so that the third MOS tube Q4 is turned on, so LED1 to LED8 are turned on, that is, the low beam is turned on, and because the third MOS tube Q4 is turned on at this time, LED9 to LED13 are short-circuited, and no current passes through LED9 to LED13 at this time, so the high beam will not be turned on.

[0109] When the high and low beams need to be turned on at the same time, the LB terminal receives a 9-16V low beam lighting signal, and the HB terminal receives a 9-16V high beam lighting signal. The high beam lighting signal is sent to the base of the third transistor Q6 after the voltage division of the anti-reverse connection diode D9 and the resistors R22 and R23, so that the third transistor Q6 is turned on, thereby pulling the gate voltage of the third MOS tube Q4 down to the ground, so that the third MOS tube Q4 is turned off. Therefore, LED1 to LED8 are connected in series with LED9 to LED13. At this time, the current of LED9 to LED13 passes normally, so the high beam and the low beam are lit at the same time.

[0110] Therefore, the embodiment of the present application utilizes the high and low beam switching sub-circuit to achieve flexible control of the low beam and the high beam, and controls the short circuit of the high beam by the third MOS tube, so that it can quickly switch between the two vehicle light lighting modes of lighting the low beam alone and lighting both the low beam and the high beam at the same time, thereby improving the flexibility and switching speed of the high and low beam switching, and there is no need to additionally set up a controller and its peripheral circuits to separately control the low beam and the high beam, which greatly simplifies the complexity of the circuit structure and reduces the hardware cost.

[0111] Accordingly, an embodiment of the present application further provides a vehicle lighting system, wherein the vehicle lighting system includes an illumination lamp 20, a signal lamp 30, and a control circuit 10 according to the above embodiment, wherein the control circuit 10 is configured to perform time-division multiplexing control on the illumination lamp and the signal lamp.

[0112] The specific configuration of each of the above modules and units and further functional description are the same as those of the above corresponding embodiments and will not be repeated here.

[0113] The vehicle lamp system proposed in this embodiment uses a control circuit to control the lighting lamp and the signal lamp to light up alternately, and uses the short visual pause of the human eye to achieve the effect of lighting the lighting lamp and the signal lamp at the same time visually. Therefore, compared with the related art, the embodiment of the present application can control the lighting of the lighting lamp and the signal lamp in time-sharing multiplexing, avoiding the circuit complexity and signal interference caused by using multiple independent control chips, not only reducing the size of the integrated circuit board, but also greatly improving the reliability and energy saving of the control circuit for the vehicle lamp.

[0114] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0115] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0116] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0117] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0118] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A control circuit for a vehicle lamp, characterized in that: The control circuit comprises: A lighting lamp driving unit, wherein the lighting lamp driving unit is adapted to receive a lighting lamp lighting signal sent by a vehicle body controller; a signal light PWM unit, the signal light PWM unit being configured to generate a signal light PWM signal according to a signal light lighting signal sent by the vehicle body controller; A constant current control unit, the constant current control unit is configured to generate a lighting lamp PWM signal according to the lighting lamp lighting signal, and control the lighting lamp and the signal lamp to light up in time-division multiplexing according to the lighting lamp PWM signal and the signal lamp PWM signal; The PWM periods of the lighting lamp PWM signal and the signal lamp PWM signal are equal, and the high level time of the signal lamp PWM signal occurs within the low level time of the lighting lamp PWM signal.

2. The control circuit according to claim 1, characterized in that: The constant current control unit comprises: A DC-DC chip, wherein the DC-DC chip is configured to generate a lighting lamp PWM signal according to the lighting lamp lighting signal, and to generate a signal lamp dimming signal according to the signal lamp PWM signal; a first MOS transistor, wherein the first MOS transistor is configured to be turned on and off according to the PWM signal of the lighting lamp to generate a dimming signal of the lighting lamp; The filtering subcircuit is configured to filter the lighting lamp dimming signal and obtain a lighting lamp constant current power supply signal.

3. The control circuit according to claim 2, characterized in that: The input end of the DC-DC chip is connected to the first output end of the lighting lamp driving unit via a first resistor, the enable end of the DC-DC chip is connected to the input end of the DC-DC chip via a second resistor, the first output end of the DC-DC chip is connected to the gate of the first MOS tube via a third resistor, the second output end of the DC-DC chip is suitable for outputting the signal lamp dimming signal, the source of the first MOS tube is grounded via a fourth resistor, and the drain of the first MOS tube is suitable for outputting the lighting lamp dimming signal.

4. The control circuit according to claim 1, characterized in that: The control circuit further comprises a linkage unit, which is configured to trigger the signal light PWM unit to send the signal light PWM signal to the constant current control unit when the lighting light PWM signal is at a low level.

5. The control circuit according to claim 4, characterized in that: The linkage unit comprises: a fifth resistor, a first end of the fifth resistor being connected to the second output end of the lighting lamp driving unit; A first transistor, wherein a collector of the first transistor is connected to the second end of the fifth resistor and has a first connection node, and an emitter of the first transistor is grounded; a first diode, wherein an anode of the first diode is connected to the first connection node, and a cathode of the first diode is connected to a trigger end of the signal light PWM unit; a first capacitor, wherein a first end of the first capacitor is connected to a base of the first transistor, and a second end of the first capacitor is connected to an emitter of the first transistor; a sixth resistor, wherein a first end of the sixth resistor is connected to the base of the first transistor, and a second end of the sixth resistor is connected to the emitter of the first transistor; A seventh resistor, wherein a first end of the seventh resistor is connected to the base of the first transistor, and a second end of the seventh resistor is suitable for receiving a lighting lamp PWM signal.

6. The control circuit according to claim 3, characterized in that: The signal light PWM unit comprises: a PWM generator, the PWM generator being configured to generate the signal light PWM signal according to the signal light lighting signal sent by the vehicle body controller, wherein an input end of the PWM generator is suitable for receiving the signal light lighting signal; a second diode, wherein an anode of the second diode is connected to an output terminal of the PWM generator, and a cathode of the second diode is connected to an enable terminal of the DC-DC chip; a third diode, wherein the cathode of the third diode is connected to the triggering end of the PWM generator, and the anode of the third diode is configured as the triggering end of the signal light PWM unit; a fourth diode, wherein an anode of the fourth diode is connected to the anode of the third diode, and a cathode of the fourth diode is connected to the second output end of the lighting lamp driving unit; A second MOS tube, wherein a gate of the second MOS tube is connected to a second output end of the DC-DC chip via an eighth resistor, a source of the second MOS tube is grounded, and a drain of the second MOS tube is connected to the signal lamp.

7. The control circuit according to any one of claims 1 to 6, characterized in that: The signal light includes at least one of a turn signal light, a position light, and a daytime running light.

8. The control circuit according to any one of claims 1 to 6, characterized in that: The lighting lamp comprises a low beam lamp and a high beam lamp, and the lighting lamp driving unit comprises: A low beam input terminal, the low beam input terminal being adapted to receive a low beam lighting signal; A high beam input terminal, the high beam input terminal being adapted to receive a high beam lighting signal; A high and low beam switching subcircuit, the high and low beam switching subcircuit comprising a third MOS tube, wherein the high and low beam switching subcircuit is configured to, when receiving the low beam lighting signal and not receiving the high beam lighting signal, turn on the third MOS tube to short-circuit the high beam, and when receiving both the low beam lighting signal and the high beam lighting signal, turn off the third MOS tube to connect the high beam and the low beam in series.

9. The control circuit according to claim 8, characterized in that: The high and low beam switching subcircuit also includes: a second triode, wherein the base of the second triode is connected to the gate and source of the third MOS tube via a second capacitor, the emitter of the second triode is grounded, the collector of the second triode is suitable for connecting to the low beam input terminal, and the collector of the second triode is connected to the gate of the third MOS tube via a ninth resistor; a third triode, wherein the base of the third triode is suitable for connecting to the high beam input terminal, the emitter of the third triode is grounded, and the collector of the third triode is suitable for connecting to the low beam input terminal; A fourth MOS tube, wherein the gate of the fourth MOS tube is connected to the collector of the third triode via a tenth resistor, the drain of the fourth MOS tube is connected to the gate and source of the third MOS tube, and the source of the fourth MOS tube is grounded.

10. A vehicle lighting system, characterized in that: The vehicle light system comprises: lighting; signal light; According to any one of claims 1 to 9, the control circuit is configured to perform time-division multiplexing control on the lighting lamp and the signal lamp.

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