Intelligent control circuit for car lamp

Abstract

The utility model discloses an intelligent control circuit for a vehicle lamp, which relates to the technical field of control circuits and comprises a detection unit, a control unit and a control unit, the ADC analog-to-digital conversion unit is used for converting analog signals of the voltage and the temperature into digital signals; the PWM dimming unit is used for outputting a control signal according to the digital signal converted by the ADC analog-to-digital conversion unit and controlling a lamp group by controlling the switching frequency and the duty ratio of current; the current balancing unit is used for uniformly distributing current in the dimming process of the PWM dimming unit; the detection unit is connected with the input end of the PWM dimming unit, the PWM dimming unit is connected with the current balancing unit, and the output end of the PWM dimming unit is connected with a driving circuit of a lamp group. According to the utility model, the problem that the whole lamp group system cannot work normally due to the short-circuit fault of a certain light source can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of control circuits, and particularly provides an intelligent control circuit for vehicle lights. Background Art

[0002] In the existing vehicle lighting safety control system, although most vehicles are equipped with a basic lighting system, there are still some significant defects in actual applications, which may seriously affect the safety and reliability of vehicle driving. The lighting systems of many vehicles lack a perfect self-check mechanism. When the vehicle starts, the lighting system often simply powers on and lights up, without in-depth fault detection. This results in some potential lighting faults, such as bulb damage and line short circuits, being difficult to detect in a timely manner, thus increasing the hidden danger of driving safety.

[0003] With the development of society and the progress of technology, electric vehicles, as an environmentally friendly and convenient way of travel, have an increasing market demand. An important part of an electric vehicle is its vehicle lighting system, which plays a crucial role in night driving. However, traditional vehicle lighting systems usually use multiple drivers to drive different light sources respectively. This design not only increases the complexity and cost of the system, but also when a certain light source fails, it may affect the entire system from working properly, causing potential safety hazards. Summary of the Utility Model

[0004] In order to solve at least one technical problem mentioned in the background art, the purpose of the utility model is to provide an intelligent control circuit for vehicle lights to avoid the problem that the entire lamp group system cannot work properly due to a short circuit fault of a certain light source.

[0005] To achieve the above purpose, the utility model provides the following technical solutions, including:

[0006] A detection unit: used to receive analog signals of voltage and temperature;

[0007] An ADC analog-to-digital conversion unit: used to convert the analog signals of voltage and temperature into digital signals;

[0008] A PWM dimming unit: used to output a control signal according to the digital signal converted by the ADC analog-to-digital conversion unit, and control the lamp group by controlling the switching frequency and duty cycle of the current;

[0009] A current equalization unit: used to make the current evenly distributed during the dimming process of the PWM dimming unit;

[0010] The detection unit is connected to the input end of the PWM dimming unit, the PWM dimming unit is connected to the current equalization unit, and the output end of the PWM dimming unit is connected to the driving circuit of the lamp group.

[0011] Further, the detection unit includes an overvoltage detection circuit, a temperature detection circuit, and a lamp group fault detection circuit;

[0012] The overvoltage detection circuit, the temperature detection circuit, and the lamp group fault detection circuit are connected to the signal input end of the PWM dimming unit.

[0013] Further, the overvoltage detection circuit is composed of a second transient voltage suppressor, a twenty-third capacitor, a twenty-seventh resistor, and a twenty-ninth resistor;

[0014] The first end of the twenty-seventh resistor is connected to the voltage input end, and the second end of the twenty-seventh resistor is connected in parallel with the first end of the twenty-ninth resistor, the first end of the twenty-third capacitor, and the first end of the second transient voltage suppressor on the PWM dimming unit; the second end of the twenty-ninth resistor is grounded, and the second end of the twenty-third capacitor and the second end of the second transient voltage suppressor are connected in parallel to the ground.

[0015] Further, the temperature detection circuit is composed of a fortieth resistor, a forty-first resistor, a forty-fourth resistor, and a twenty-ninth capacitor;

[0016] The first end of the fortieth resistor is connected to the PWM dimming unit, and the second end of the fortieth resistor, the first end of the twenty-ninth capacitor, and the first end of the forty-first resistor are connected in parallel at the positive end of the temperature detection; the second end of the twenty-ninth capacitor is connected in parallel with the first end of the forty-fourth resistor to the ground, the second end of the forty-fourth resistor is connected to the negative end of the temperature detection, and the second end of the forty-first resistor is connected to the PWM dimming unit.

[0017] Further, the lamp group fault detection circuit is composed of a fifth transient voltage suppressor, a thirtieth capacitor, a thirty-first capacitor, a thirty-eighth resistor, a thirty-ninth resistor, a forty-second resistor, and a forty-third resistor;

[0018] The first ends of the thirty-eighth resistor and the thirty-ninth resistor are respectively connected to the lamp group, and the second end of the thirty-eighth resistor is connected in parallel with the first end of the forty-second resistor and the first end of the thirtieth capacitor at the first end of the fifth transient voltage suppressor;

[0019] The second end of the thirty-ninth resistor is connected in parallel with the first end of the forty-third resistor and the first end of the thirty-first capacitor at the second end of the fifth transient voltage suppressor;

[0020] The second ends of the forty-second resistor and the forty-third resistor are connected in parallel to the ground, and the second end of the thirtieth capacitor, the second end of the thirty-first capacitor, and the third end of the fifth transient voltage suppressor are connected in parallel to the ground.

[0021] Further, the ADC analog-to-digital conversion unit uses the model AD7899, the PWM dimming unit uses the model TL494, and the current balancing unit uses the model INA219.

[0022] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0023] The present utility model realizes that in a vehicle lighting system, a detection unit can actively complete a self-check when the system is powered on, check whether the high-beam and low-beam light source boards are short-circuited or open-circuited, and adjust the current according to the self-check results, preventing in the case where the high-beam and low-beam work simultaneously, due to the lack of one of the light sources, the two-channel current is applied to one light source, resulting in the light source board being burned out, avoiding the failure of the entire lamp group due to a short-circuit fault in one of the high-beam and low-beam light sources. When one of them is short-circuited, the short-circuited channel will be disconnected, and the current will be reduced to ensure that the other light source can work normally. Description of the Drawings

[0024] Figure 1 It is a structural block diagram of the intelligent control circuit for vehicle lights provided by an embodiment of the present utility model;

[0025] Figure 2 It is a schematic diagram of the overvoltage detection circuit in the intelligent control circuit for vehicle lights provided by an embodiment of the present utility model;

[0026] Figure 3 It is a schematic diagram of the temperature detection circuit in the intelligent control circuit for vehicle lights provided by an embodiment of the present utility model;

[0027] Figure 4 It is a schematic diagram of the lamp group fault detection circuit in the intelligent control circuit for vehicle lights provided by an embodiment of the present utility model. Detailed Embodiment

[0028] The technical solutions in the embodiments of the present utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without any creative work shall fall within the protection scope of the present utility model.

[0029] Please refer to Figure 1 , this embodiment provides an intelligent control circuit for vehicle lights, including:

[0030] A detection unit: used to receive analog signals of voltage and temperature;

[0031] An ADC analog-to-digital conversion unit: used to convert the analog signals of voltage and temperature into digital signals;

[0032] PWM Dimming Unit: It is used to output a control signal according to the digital signal converted by the ADC Analog-to-Digital Conversion Unit, and control the lamp group by controlling the switching frequency and duty cycle of the current.

[0033] Current Balancing Unit: It is used to evenly distribute the current during the dimming process of the PWM Dimming Unit.

[0034] The Detection Unit is connected to the input end of the PWM Dimming Unit, the PWM Dimming Unit is connected to the Current Balancing Unit, and the output end of the PWM Dimming Unit is connected to the driving circuit of the lamp group.

[0035] Specifically, the intelligent headlight control circuit is a single-channel LED driver that utilizes ADC analog-to-digital conversion unit, MOSFET switch, PWM dimming, and current balancing technologies. In the lamp group of the vehicle lighting system, it checks whether the high-beam and low-beam light source boards are short-circuited or open-circuited, and actively realizes channel isolation and maximum current adjustment according to the self-check results, preventing the light source board from burning out due to the application of the current of both channels to one light source due to the lack of one of the light sources under the logic of simultaneous operation of high-beam and low-beam lights. In addition, the intelligent lamp control protection technology can continuously monitor the working status of the high-beam and low-beam light sources after power-on. A short-circuit fault in one of the high-beam and low-beam light sources will cause the entire lamp to fail. Therefore, the intelligent lamp control protection technology will monitor the working conditions of the two light sources in real time. When one of them is short-circuited, it will disconnect the short-circuited channel and reduce the current to ensure that the other light source can work normally.

[0036] Specifically, the Detection Unit is responsible for receiving the analog signals of voltage and temperature. These signals may come from the light source board or other relevant sensors, and are used to judge the working status of the light source board. The ADC Analog-to-Digital Conversion Unit is used to convert the analog signals received by the Detection Unit into digital signals for subsequent digital processing. The PWM Dimming Unit then outputs a control signal according to the digital signal output by the ADC Analog-to-Digital Conversion Unit to adjust the switching frequency and duty cycle of the current, thereby controlling the brightness of the lamp group. In addition, it may also adjust the current output according to the self-check results to prevent damage to the light source board caused by short circuit or open circuit.

[0037] Specifically, the Current Balancing Unit ensures that during the PWM dimming process, the current can be evenly distributed to each light source board, preventing a certain light source board from being damaged due to overcurrent. During the self-check process, the Detection Unit may measure the voltage and temperature of the light source board to judge whether it is in a normal working state. If a short circuit or open circuit is found, the PWM Dimming Unit can adjust the output current or disconnect the short-circuited channel according to the digital signal provided by the ADC Analog-to-Digital Conversion Unit, and reduce the current of the remaining light sources to ensure their normal operation.

[0038] Among them, the Detection Unit includes an overvoltage detection circuit, a temperature detection circuit, and a lamp group fault detection circuit;

[0039] The overvoltage detection circuit, temperature detection circuit, lamp group fault detection circuit are connected to the signal input end of the PWM dimming unit.

[0040] Refer to Figure 2 , wherein, the overvoltage detection circuit is composed of a second transient voltage suppressor TVS2, a twenty-third capacitor C23, a twenty-seventh resistor R27 and a twenty-ninth resistor R29;

[0041] The first end of the twenty-seventh resistor R27 is connected to the voltage input end VCC, and the second end of the twenty-seventh resistor R27, the first end of the twenty-ninth resistor R29, the first end of the twenty-third capacitor C23 and the first end of the second transient voltage suppressor TVS2 are connected in parallel to the PWM dimming unit; the second end of the twenty-ninth resistor R29 is grounded, and the second end of the twenty-third capacitor C23 and the second end of the second transient voltage suppressor TVS2 are connected in parallel to the ground.

[0042] Refer to Figure 3 , wherein, the temperature detection circuit is composed of a fortieth resistor R40, a forty-first resistor R41, a forty-fourth resistor R44 and a twenty-ninth capacitor C29;

[0043] The first end of the fortieth resistor R40 is connected to the PWM dimming unit, and the second end of the fortieth resistor R40, the first end of the twenty-ninth capacitor C29 and the first end of the forty-first resistor R41 are connected in parallel to the positive temperature detection terminal NTC1+; the second end of the twenty-ninth capacitor C29 is connected in parallel to the ground with the first end of the forty-fourth resistor R44; the second end of the forty-fourth resistor R44 is connected to the negative temperature detection terminal NTC1-; the second end of the forty-first resistor R41 is connected to the PWM dimming unit.

[0044] Refer to Figure 4 , wherein, the lamp group fault detection circuit is composed of a fifth transient voltage suppressor TVS5, a thirtieth capacitor C30, a thirty-first capacitor C31, a thirty-eighth resistor R38, a thirty-ninth resistor R39, a forty-second resistor R42 and a forty-third resistor R43;

[0045] The first end of the thirty-eighth resistor R38 and the first end of the thirty-ninth resistor R39 are respectively connected to the lamp group, and the second end of the thirty-eighth resistor R38, the first end of the forty-second resistor R42 and the first end of the thirtieth capacitor C30 are connected in parallel to the first end of the fifth transient voltage suppressor TVS5;

[0046] The second end of the thirty-ninth resistor R39, the first end of the forty-third resistor R43 and the first end of the thirty-first capacitor C31 are connected in parallel to the second end of the fifth transient voltage suppressor TVS5;

[0047] The second terminal of the forty-second resistor R42 and the second terminal of the forty-third resistor R43 are connected in parallel to ground. The second terminal of the thirtieth capacitor C30, the second terminal of the thirty-first capacitor C31, and the third terminal of the fifth transient voltage suppressor TVS5 are connected in parallel to ground.

[0048] Among them, the ADC analog-to-digital conversion unit uses the model AD7899, the PWM dimming unit uses the model TL494, and the current balancing unit uses the model INA219.

[0049] Specifically, a high-speed MOSFET switch, model IRF540N, is selected. It has a low on-resistance and can effectively reduce the power consumption of the system. Then, a PWM dimming chip, model TL494, is selected. It can generate a stable PWM signal for adjusting the brightness of the LED. Finally, a current balancing chip, model INA219, is selected. It can achieve current balancing for two channels.

[0050] Specifically, power-on self-check and fault judgment, system initialization: When the vehicle lighting system is powered on, the detection unit starts to work and receives voltage and temperature analog signals from the light source board and other relevant sensors. Analog signal conversion: The ADC analog-to-digital conversion unit converts these analog signals into digital signals for subsequent processing. Self-check and fault judgment: Software or hardware logic determines whether the light source board is in a normal working state based on the converted digital signals. For example, by comparing whether the voltage value is within the preset range, or by judging whether there is an overheating phenomenon based on the temperature value. If an abnormality such as a short circuit or an open circuit is detected, the fault handling process is entered.

[0051] Specifically, fault handling and current adjustment, fault handling: When a short circuit or open circuit fault is detected, the PWM dimming unit takes different measures according to the fault type, short circuit or open circuit, and the position, low beam or high beam. For example, if the low beam light source board is short-circuited, the PWM dimming unit can disconnect the low beam channel and reduce the current of the high beam channel to ensure the normal operation of the high beam light source.

[0052] Specifically, current adjustment: During the fault handling process, the PWM dimming unit changes the magnitude of the output current by adjusting the switching frequency and duty cycle of the control signal. This adjustment can be based on a preset fault handling strategy or can be dynamically adjusted according to real-time voltage and temperature data. Current balancing: The current balancing unit ensures that the current is evenly distributed on the remaining working light source boards throughout the process. This helps prevent a light source board from being damaged due to overcurrent and improves the reliability and stability of the system.

[0053] Specifically, continuous monitoring and protection. Continuous monitoring: During the normal operation of the system, the detection unit and the ADC analog-to-digital conversion unit continuously receive and convert the analog signals of voltage and temperature to understand the working state of the light source board in real time. Protection mechanism: If any abnormalities are found during continuous monitoring, such as overheating, overcurrent, etc., the PWM dimming unit can immediately take actions, such as reducing the current, closing the faulty channel, etc., to protect the light source board and the entire lighting system from damage.

[0054] The utility model realizes that in a vehicle lighting system, the detection unit can actively complete a self-check when the system is powered on, check whether the high-beam and low-beam light source boards are short-circuited or open-circuited, and adjust the current according to the self-check results, preventing the light source board from being burned out due to the lack of one of the light sources and the current of both channels being applied to one light source when the high-beam and low-beam are working simultaneously, avoiding the failure of the entire lamp group due to a short-circuit fault in one of the high-beam and low-beam light sources. When one of them is short-circuited, the short-circuited channel will be disconnected and the current will be reduced to ensure that the other light source can work normally.

[0055] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims in the present utility model.

Claims

1. An intelligent control circuit for a vehicle lamp, characterized in that, Comprising: Detection unit: for receiving analog signals of voltage and temperature; ADC analog-to-digital conversion unit: for converting the analog signals of voltage and temperature into digital signals; PWM dimming unit: for outputting a control signal according to the digital signals converted by the ADC analog-to-digital conversion unit, and controlling the lamp group by controlling the switching frequency and duty cycle of the current; Current equalization unit: for making the current evenly distributed during the dimming process of the PWM dimming unit; The detection unit is connected to the input end of the PWM dimming unit, the PWM dimming unit is connected to the current equalization unit, and the output end of the PWM dimming unit is connected to the drive circuit of the lamp group.

2. The intelligent control circuit for vehicle lamps according to claim 1, wherein The detection unit includes an overvoltage detection circuit, a temperature detection circuit and a lamp group fault detection circuit; The overvoltage detection circuit, the temperature detection circuit and the lamp group fault detection circuit are connected to the signal input end of the PWM dimming unit.

3. The intelligent control circuit for a vehicle lamp according to claim 2, wherein, The overvoltage detection circuit is composed of a second transient voltage suppressor, a twenty-third capacitor, a twenty-seventh resistor and a twenty-ninth resistor; The first end of the twenty-seventh resistor is connected to the voltage input end, and the second end of the twenty-seventh resistor, the first end of the twenty-ninth resistor, the first end of the twenty-third capacitor and the first end of the second transient voltage suppressor are connected in parallel to the PWM dimming unit; the second end of the twenty-ninth resistor is grounded, and the second end of the twenty-third capacitor and the second end of the second transient voltage suppressor are connected in parallel to the ground.

4. The intelligent control circuit for a vehicle lamp according to claim 2, wherein The temperature detection circuit is composed of a fortieth resistor, a forty-first resistor, a forty-fourth resistor and a twenty-ninth capacitor; The first end of the fortieth resistor is connected to the PWM dimming unit, and the second end of the fortieth resistor, the first end of the twenty-ninth capacitor and the first end of the forty-first resistor are connected in parallel to the positive terminal of the temperature detection; the second end of the twenty-ninth capacitor is connected in parallel to the ground with the first end of the forty-fourth resistor, the second end of the forty-fourth resistor is connected to the negative terminal of the temperature detection, and the second end of the forty-first resistor is connected to the PWM dimming unit.

5. The intelligent control circuit for a vehicle lamp according to claim 2, wherein The lamp group fault detection circuit is composed of a fifth transient voltage suppressor, a thirtieth capacitor, a thirty-first capacitor, a thirty-eighth resistor, a thirty-ninth resistor, a forty-second resistor and a forty-third resistor; The first ends of the thirty-eighth resistor and the thirty-ninth resistor are respectively connected to the lamp group, and the second end of the thirty-eighth resistor is connected in parallel to the first end of the forty-second resistor and the first end of the thirtieth capacitor at the first end of the fifth transient voltage suppressor; The second end of the thirty-ninth resistor is connected in parallel to the first end of the forty-third resistor and the first end of the thirty-first capacitor at the second end of the fifth transient voltage suppressor; The second ends of the forty-second resistor and the forty-third resistor are connected in parallel to the ground, and the second end of the thirtieth capacitor, the second end of the thirty-first capacitor and the third end of the fifth transient voltage suppressor are connected in parallel to the ground.

6. The intelligent control circuit for a vehicle lamp according to claim 1, wherein, The ADC analog-to-digital conversion unit uses the model AD7899, the PWM dimming unit uses the model TL494, and the current balancing unit uses the model INA219.

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