Intelligent temperature control start-stop circuit and method thereof

Abstract

The application discloses an intelligent temperature control start-stop circuit, which comprises a power module, a temperature sensor module, a microcontroller module, a fan driving module, a fan self-checking module, a light emitting diode constant current driving module and an over-temperature protection module. The power module outputs a working voltage; the temperature sensor module outputs a temperature sampling signal, and the fan self-checking module outputs a fan state detection signal; the microcontroller module controls the start-stop and rotating speed of a cooling fan through the fan driving module according to the signals, and controls the light emitting diode constant current driving module and the over-temperature protection module to adjust the output power of a light emitting diode light source. The application can reduce invalid operation of the cooling fan, and limit the output power of the light emitting diode light source when the fan is abnormal or the temperature is too high.

Description

Technical Field

[0001] This invention relates to the field of vehicle lighting technology, specifically to an intelligent temperature-controlled start-stop circuit and method thereof. Background Technology

[0002] LED automotive lights are widely used in the automotive lighting field due to their high luminous efficiency, fast response speed, and long lifespan. LED light sources generate heat during operation, especially in high-power and compact installation environments, where heat easily accumulates in and around the LED source. To reduce operating temperature, existing LED automotive lights typically employ passive cooling with heat sinks or forced air cooling with cooling fans to accelerate heat transfer to the external environment.

[0003] Existing LED automotive lights that use cooling fans typically control the cooling fan to run continuously or control its start / stop based on a single temperature threshold. This makes it difficult to adapt to the heat dissipation requirements of LED automotive lights under different ambient temperatures and workloads. Continuous operation of the cooling fan increases energy consumption and operating noise, and accelerates the mechanical wear of the cooling fan; frequent start-stop cycles will affect the lifespan of the cooling fan. In addition, when the cooling fan stalls, experiences abnormal current, or other operational malfunctions, existing automotive lights cannot respond in a timely manner, easily leading to continuous heat accumulation, causing light decay, performance degradation, or even damage to the LED light source.

[0004] Therefore, the technical problem to be solved by this application is how to improve the adaptability and reliability of the LED vehicle lamp heat dissipation system under different temperature conditions and abnormal fan conditions, while taking into account heat dissipation effect, fan life, operating noise and energy consumption. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an intelligent temperature control start-stop circuit and method to overcome the shortcomings of the existing LED vehicle light cooling system, which has insufficient adaptability to the cooling fan operation status under different temperature conditions, and insufficient protection capability when the cooling fan operates abnormally or the vehicle light temperature is too high, resulting in long ineffective operation time of the cooling fan, shortened service life and reduced reliability of LED light source.

[0006] The purpose of this invention is to address the defects and shortcomings of the existing technology by providing an intelligent temperature control start-stop circuit for use in LED vehicle lights, including a power supply module 100, a temperature sensor module 200, a microcontroller module 300, a fan drive module 400, a fan self-test module 500, an LED constant current drive module 600, and an over-temperature protection module 700. The power module 100 is electrically connected to the temperature sensor module 200, the microcontroller module 300, the fan drive module 400, and the LED constant current drive module 600, respectively. The power module 100 has the function of protecting and stepping down the input power supply and outputting the corresponding working voltage. The temperature sensor module 200 is electrically connected to the microcontroller module 300, and the temperature sensor module 200 has the function of detecting the temperature of the LED vehicle light and outputting a temperature sampling signal; The microcontroller module 300 is electrically connected to the fan drive module 400, the fan self-test module 500, the LED constant current drive module 600, and the over-temperature protection module 700, respectively. The microcontroller module 300 has the functions of controlling the start and stop and speed of the cooling fan according to the temperature sampling signal, judging the operating status of the cooling fan according to the fan status detection signal, and controlling the output power of the LED light source. The fan drive module 400 is connected between the power supply module 100, the microcontroller module 300 and the cooling fan. The fan drive module 400 has the function of connecting or disconnecting the power supply path of the cooling fan according to the fan control signal output by the microcontroller module 300 and adjusting the speed of the cooling fan. The fan self-test module 500 is connected between the cooling fan and the microcontroller module 300. The fan self-test module 500 has the function of detecting the current flowing through the cooling fan and outputting the fan status detection signal to the microcontroller module 300. The LED constant current driving module 600 is connected between the power supply module 100, the microcontroller module 300 and the LED light source. The LED constant current driving module 600 has the function of outputting a constant driving current to the LED light source and adjusting the output power of the LED light source according to the dimming control signal. The over-temperature protection module 700 is connected between the microcontroller module 300 and the LED constant current drive module 600. The over-temperature protection module 700 has the function of limiting the output of the LED constant current drive module 600 according to the over-temperature control signal output by the microcontroller module 300.

[0007] Furthermore, the power module 100 includes a power input terminal U3, a fuse element U1, an input capacitor C1, a step-down chip U2, an energy storage inductor L1, a freewheeling diode D1, a first feedback resistor R1, a second feedback resistor R2, an output capacitor C2, and a power output terminal U4. The first pin of the power input terminal U3 is connected to the protected power supply terminal through the fuse element U1, and the second pin of the power input terminal U3 is grounded; The input capacitor C1 is connected between the protected power supply terminal and the ground terminal, and the input terminal of the step-down chip U2 is connected to the protected power supply terminal. The switching terminal of the step-down chip U2 is connected to the regulated output terminal through the energy storage inductor L1, and the freewheeling diode D1 is connected between the switching terminal and the ground terminal of the step-down chip U2. The first feedback resistor R1 and the second feedback resistor R2 are connected in series between the regulated output terminal and the ground terminal, and the connection node of the first feedback resistor R1 and the second feedback resistor R2 is connected to the feedback terminal of the step-down chip U2. The output capacitor C2 is connected between the regulated output terminal and the ground terminal. The first pin of the power output terminal U4 is connected to the regulated output terminal, and the second pin of the power output terminal U4 is grounded.

[0008] Furthermore, the temperature sensor module 200 includes a negative temperature coefficient thermistor R13, a voltage divider resistor R14, and a filter capacitor C10; The negative temperature coefficient thermistor R13 is connected between the regulated output terminal of the power module 100 and the temperature sampling node. The voltage divider resistor R14 is connected between the temperature sampling node and the ground terminal, the filter capacitor C10 is connected in parallel with the voltage divider resistor R14, and the temperature sampling node is connected to the temperature sampling terminal of the microcontroller module 300.

[0009] Furthermore, the microcontroller module 300 includes a microcontroller U5, a crystal oscillator X1, a first oscillation capacitor C3, a second oscillation capacitor C4, a reset resistor R3, a reset capacitor C5, and a decoupling capacitor C6. The power supply terminal of the microcontroller U5 is connected to the regulated output terminal of the power module 100, and the ground terminal of the microcontroller U5 is grounded. The crystal oscillator X1 is connected between the two oscillation terminals of the microcontroller U5, and the first oscillation capacitor C3 and the second oscillation capacitor C4 are respectively connected between the corresponding oscillation terminal and the ground terminal; The reset resistor R3 is connected between the regulated output terminal and the reset terminal of the microcontroller U5, the reset capacitor C5 is connected between the reset terminal of the microcontroller U5 and the ground terminal, and the decoupling capacitor C6 is connected between the power supply terminal and the ground terminal of the microcontroller U5. The fan control terminal, fan status detection terminal, dimming control terminal, and over-temperature control terminal of the microcontroller U5 are respectively connected to the fan drive module 400, the fan self-test module 500, the LED constant current drive module 600, and the over-temperature protection module 700.

[0010] Furthermore, the fan drive module 400 includes a fan connector U9, a P-channel MOSFET Q1, a first transistor Q2, a gate pull-up resistor R11, and a base limiting current resistor R12. The source of the P-channel MOSFET Q1 is connected to the protected power supply terminal of the power module 100, the drain of the P-channel MOSFET Q1 is connected to the first pin of the fan connector U9, and the second pin of the fan connector U9 is connected to the fan self-test module 500. The gate pull-up resistor R11 is connected between the source and gate of the P-channel field-effect transistor Q1; The collector of the first transistor Q2 is connected to the gate of the P-channel field-effect transistor Q1, the emitter of the first transistor Q2 is grounded, and the base of the first transistor Q2 is connected to the fan control terminal of the microcontroller module 300 through the base current limiting resistor R12, so as to control the on / off state of the P-channel field-effect transistor Q1 according to the fan control signal.

[0011] Furthermore, the fan self-test module 500 includes a current sampling resistor R5, a detection resistor R6, a second transistor Q3, and a detection filter capacitor C7; The current sampling resistor R5 is connected between the second pin of the fan connector U9 and the ground terminal, and the detection resistor R6 is connected between the second pin of the fan connector U9 and the base of the second transistor Q3; The emitter of the second transistor Q3 is grounded, and the collector of the second transistor Q3 is connected to the fan status detection terminal of the microcontroller module 300. The detection filter capacitor C7 is connected between the collector of the second transistor Q3 and the ground terminal, so that the second transistor Q3 changes its conduction state according to the sampling voltage formed across the current sampling resistor R5 and outputs the fan status detection signal.

[0012] Furthermore, the LED constant current driving module 600 includes a constant current driving chip U7, a driving freewheeling diode D3, a driving filter capacitor C8, a current setting resistor R7, a first LED LED2, a second LED LED4, a third LED LED6, and a driving inductor L3. The power supply terminal of the constant current drive chip U7 is connected to the protected power supply terminal of the power module 100, and the drive filter capacitor C8 is connected between the power supply terminal and the ground terminal of the constant current drive chip U7. The driving freewheeling diode D3 is connected between the switching terminal of the constant current driving chip U7 and the protected power supply terminal, and the current setting resistor R7 is connected between the protected power supply terminal and the current detection terminal of the constant current driving chip U7. The first light-emitting diode LED2, the second light-emitting diode LED4, and the third light-emitting diode LED6 are connected in series between the current detection terminal of the constant current driving chip U7 and the driving inductor L3, and the other end of the driving inductor L3 is connected to the switching terminal of the constant current driving chip U7. The over-temperature protection module 700 includes a dimming input resistor R8, a third transistor Q4, and an over-temperature control resistor R9. The dimming input resistor R8 is connected between the dimming control terminal of the microcontroller module 300 and the dimming terminal of the constant current drive chip U7. The collector of the third transistor Q4 is connected to the dimming terminal of the constant current drive chip U7, the emitter of the third transistor Q4 is grounded, and the base of the third transistor Q4 is connected to the over-temperature control terminal of the microcontroller module 300 through the over-temperature control resistor R9.

[0013] On the other hand, the present invention also provides an intelligent temperature control start-stop method, applied to LED vehicle lights, comprising: In response to the power-on of the LED headlights, the cooling fan is controlled to run within a preset self-test duration; During the operation of the cooling fan, a fan status detection signal is acquired, and the operation of the cooling fan is determined based on the fan status detection signal. If the cooling fan is found to be operating abnormally, the output power of the light-emitting diode light source is reduced to the first protection power. Acquire the temperature sampling signal of the LED vehicle light, and determine the corresponding current temperature based on the temperature sampling signal; The target operating state of the cooling fan is determined based on the temperature range of the current temperature, and when the current temperature drops, the target operating state is determined according to the down-level temperature threshold that is lower than the corresponding up-level temperature threshold. Based on the target operating state, a fan control signal is output to control the cooling fan to stop or operate at a corresponding speed; The current temperature is compared with the over-temperature protection threshold. When the current temperature is higher than the over-temperature protection threshold, the output power of the LED light source is reduced to a second protection power. When the current temperature is reduced to below the over-temperature recovery threshold, the output power of the LED light source is restored. The over-temperature recovery threshold is lower than the over-temperature protection threshold.

[0014] Furthermore, the preset self-test duration is 3 seconds; Within the preset self-test duration, a fan status detection signal is generated based on the operating current flowing through the cooling fan. When the operating current is not within the preset current range, it is determined that the cooling fan is stalled or the current is abnormal, and the output power of the light-emitting diode light source is reduced to 50% of the rated output power.

[0015] Furthermore, determining the target operating state of the cooling fan based on the temperature range of the current temperature includes: when the current temperature is below 55°C, determining the target operating state as a stopped state; When the current temperature is between 55°C and 70°C, the target operating state is determined to be a low-speed operating state, and the speed corresponding to the low-speed operating state is 3000 rpm. When the current temperature is between 70°C and 85°C, the target operating state is determined to be a medium-speed operating state, and the speed corresponding to the medium-speed operating state is 5000 rpm. When the current temperature is higher than 85°C, the target operating state is determined to be a high-speed operating state, and the speed corresponding to the high-speed operating state is 7000 rpm. When the current temperature drops, each of the downgrade temperature thresholds is set to be 5°C lower than the corresponding upgrade temperature threshold. The over-temperature protection threshold is set to 95°C. When the current temperature is higher than 95°C, the output power of the LED light source is reduced to 70% of the rated output power, and the output power of the LED light source is restored when the current temperature drops below 85°C.

[0016] This invention discloses an intelligent temperature-controlled start-stop circuit, comprising a power supply module, a temperature sensor module, a microcontroller module, a fan drive module, a fan self-test module, an LED constant current drive module, and an over-temperature protection module. The power supply module outputs a working voltage; the temperature sensor module outputs a temperature sampling signal; and the fan self-test module outputs a fan status detection signal. Based on these signals, the microcontroller module controls the start-stop and speed of the cooling fan via the fan drive module, and controls the LED constant current drive module and the over-temperature protection module to adjust the output power of the LED light source. This invention reduces ineffective operation of the cooling fan and limits the output power of the LED light source when the fan malfunctions or the temperature is too high. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an intelligent temperature control start-stop circuit architecture according to the present invention; Figure 2 This is a schematic diagram of a power module circuit structure according to the present invention; Figure 3 This is a schematic diagram of the circuit structure of a temperature sensor module according to the present invention; Figure 4 This is a schematic diagram of a microcontroller module circuit structure according to the present invention; Figure 5 This is a schematic diagram of the fan and its self-test circuit structure of the present invention; Figure 6 This is a schematic diagram of the circuit structure of the LED constant current drive module of the present invention.

[0019] Figure label: 100. Power module; 200. Temperature sensor module; 300. Microcontroller module; 400. Fan drive module; 500. Fan self-test module; 600. LED constant current drive module; 700. Over-temperature protection module. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings.

[0021] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive element, but such modifications are protected by patent law as long as they fall within the scope of the claims of the present invention.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] Reference Figure 1This embodiment provides an intelligent temperature-controlled start-stop circuit for use in LED vehicle lights. It includes a power supply module 100, a temperature sensor module 200, a microcontroller module 300, a fan drive module 400, a fan self-test module 500, an LED constant current drive module 600, and an over-temperature protection module 700. The power supply module 100 is electrically connected to the temperature sensor module 200, the microcontroller module 300, the fan drive module 400, and the LED constant current drive module 600. The power supply module 100 has the function of protecting and stepping down the input power supply, and outputting a corresponding operating voltage. The temperature sensor module 200 is electrically connected to the microcontroller module 300, and the temperature sensor module 200 has the function of detecting the temperature of the LED vehicle light and outputting a temperature sampling signal. The microcontroller module 300 is electrically connected to the fan drive module 400, the fan self-test module 500, the LED constant current drive module 600, and the over-temperature protection module 700, respectively. The microcontroller module 300 has the function of controlling the start, stop, and speed of the cooling fan according to the temperature sampling signal, determining the operating status of the cooling fan according to the fan status detection signal, and controlling the output power of the LED light source. The fan drive module 400 is connected between the power supply module 100, the microcontroller module 300, and the cooling fan. The fan drive module 400 has the function of connecting or disconnecting the power supply path of the cooling fan according to the fan control signal output by the microcontroller module 300, and adjusting the speed of the cooling fan. The fan self-test module 500 is connected between the cooling fan and the microcontroller module 300. The fan self-test module 500 has the function of detecting the current flowing through the cooling fan and outputting the fan status detection signal to the microcontroller module 300. The light-emitting diode... The LED constant current drive module 600 is connected between the power supply module 100, the microcontroller module 300, and the LED light source. The LED constant current drive module 600 has the function of outputting a constant drive current to the LED light source and adjusting the output power of the LED light source according to the dimming control signal. The over-temperature protection module 700 is connected between the microcontroller module 300 and the LED constant current drive module 600. The over-temperature protection module 700 has the function of limiting the output of the LED constant current drive module 600 according to the over-temperature control signal output by the microcontroller module 300.

[0025] In this embodiment, the aforementioned intelligent temperature control start-stop circuit is housed within the LED headlight. The power module 100 is connected to the vehicle's power supply and provides protection and step-down of the input 12V or 24V voltage. The protected input voltage powers the fan drive module 400 and the LED constant current drive module 600, while the stepped-down 3.3V operating voltage powers the temperature sensor module 200 and the microcontroller module 300.

[0026] In the aforementioned temperature sensor module 200, the negative temperature coefficient thermistor R13 is disposed on the light-emitting diode light source substrate or an adjacent adapter board, and forms a voltage divider circuit with the voltage divider resistor R14. The resistance value of the negative temperature coefficient thermistor R13 changes with temperature, causing the voltage of the temperature sampling node to change accordingly. After being filtered by the filter capacitor C10, the voltage is input to the temperature sampling terminal of the microcontroller U5.

[0027] The microcontroller U5 determines the current temperature based on the temperature sampling signal and outputs a fan control signal to the fan drive module 400. The fan drive module 400 controls the P-channel MOSFET Q1 to turn on or off through the first transistor Q2, thereby connecting or disconnecting the power supply path of the cooling fan. The microcontroller U5 can also adjust the duty cycle of the fan control signal so that the cooling fan runs at a speed corresponding to the current temperature.

[0028] The operating current of the cooling fan flows through the current sampling resistor R5 in the fan self-test module 500, forming a corresponding sampling voltage. This sampling voltage controls the conduction state of the second transistor Q3 through the detection resistor R6, thereby forming a fan status detection signal and feeding it back to the microcontroller U5, enabling the microcontroller U5 to determine whether the cooling fan is operating normally.

[0029] The aforementioned LED constant current drive module 600 forms a constant current drive circuit through the constant current drive chip U7, the current setting resistor R7, the drive inductor L3, and the drive freewheeling diode D3 to output a constant drive current to the LED light source. The dimming control signal output by the microcontroller U5 is transmitted to the dimming terminal of the constant current drive chip U7 to adjust the output power of the LED light source.

[0030] When the headlight temperature exceeds the over-temperature protection threshold, the microcontroller U5 outputs an over-temperature control signal to the over-temperature protection module 700, which turns on the third transistor Q4 and pulls down the dimming terminal voltage of the constant current driver chip U7, thereby limiting the output of the LED constant current driver module 600 and realizing over-temperature protection for the LED light source.

[0031] Further, the power module 100 includes a power input terminal U3, a fuse U1, an input capacitor C1, a step-down chip U2, an energy storage inductor L1, a freewheeling diode D1, a first feedback resistor R1, a second feedback resistor R2, an output capacitor C2, and a power output terminal U4; the first pin of the power input terminal U3 is connected to the protected power supply terminal through the fuse U1, and the second pin of the power input terminal U3 is grounded; the input capacitor C1 is connected between the protected power supply terminal and the ground terminal, and the input terminal of the step-down chip U2 is connected to the protected power supply terminal; the step-down chip U2... The switching terminal of the step-down chip U2 is connected to the regulated output terminal through the energy storage inductor L1. The freewheeling diode D1 is connected between the switching terminal and the ground terminal of the step-down chip U2. The first feedback resistor R1 and the second feedback resistor R2 are connected in series between the regulated output terminal and the ground terminal. The connection node of the first feedback resistor R1 and the second feedback resistor R2 is connected to the feedback terminal of the step-down chip U2. The output capacitor C2 is connected between the regulated output terminal and the ground terminal. The first pin of the power output terminal U4 is connected to the regulated output terminal, and the second pin of the power output terminal U4 is grounded.

[0032] In this embodiment, as Figure 2 The schematic diagram of a power module circuit is shown below. Pin 1 of the power input terminal U3 is used to connect to a 12V vehicle power supply and is connected to the protected power supply terminal via fuse U1; pin 2 of the power input terminal U3 is grounded. When the input current increases abnormally, fuse U1 disconnects the input power supply path to protect the subsequent circuits. The positive terminal of the input capacitor C1 is connected to the protected power supply terminal, and the negative terminal is grounded, used to filter out ripple and interference in the input voltage.

[0033] The step-down chip U2 uses an XL7005A, with its input connected to the protected power supply and its switching terminal connected to the regulated output terminal via an energy storage inductor L1. The freewheeling diode D1 uses a Schottky diode SS34, with its cathode connected to the switching terminal of the step-down chip U2 and its anode grounded, to provide a freewheeling path for the energy storage inductor L1 when the switching terminal of the step-down chip U2 is turned off.

[0034] The first feedback resistor R1 is connected between the regulated output terminal and the feedback terminal, and the second feedback resistor R2 is connected between the feedback terminal and the ground terminal. The first feedback resistor R1 and the second feedback resistor R2 divide the voltage at the regulated output terminal and feed the voltage division result back to the buck chip U2, causing the buck chip U2 to adjust the switching state and stabilize the output voltage at 3.3V.

[0035] The positive terminal of the output capacitor C2 is connected to the regulated output terminal, and the negative terminal is grounded, used to filter the stepped-down voltage. Pin 1 of the power output terminal U4 outputs a 3.3V operating voltage, and pin 2 is grounded, thus providing a stable operating voltage for the temperature sensor module 200 and the microcontroller module 300.

[0036] Furthermore, the temperature sensor module 200 includes a negative temperature coefficient thermistor R13, a voltage divider resistor R14, and a filter capacitor C10; the negative temperature coefficient thermistor R13 is connected between the regulated output terminal of the power supply module 100 and the temperature sampling node; the voltage divider resistor R14 is connected between the temperature sampling node and the ground terminal; the filter capacitor C10 is connected in parallel with the voltage divider resistor R14; and the temperature sampling node is connected to the temperature sampling terminal of the microcontroller module 300.

[0037] In this embodiment, as Figure 3 The schematic diagram of a temperature sensor module circuit is shown below. The negative temperature coefficient thermistor R13 is an MF52A103F3950 type thermistor, which is mounted on the LED light source substrate or an adjacent adapter board to detect the temperature of the LED vehicle light. One end of the negative temperature coefficient thermistor R13 is connected to a 3.3V regulated output terminal, and the other end is connected to the temperature sampling node NET_ADC_TEMP. The voltage divider resistor R14 is a 10kΩ resistor, connected between the temperature sampling node NET_ADC_TEMP and the ground terminal.

[0038] The resistance of the negative temperature coefficient thermistor R13 decreases as temperature increases, causing the voltage of the temperature sampling node NET_ADC_TEMP to increase accordingly. The filter capacitor C10, a 100nF capacitor, is connected in parallel with the voltage divider resistor R14 to filter out high-frequency interference in the temperature sampling signal. The temperature sampling node NET_ADC_TEMP is connected to the temperature sampling terminal of microcontroller U5, enabling microcontroller U5 to determine the current temperature of the LED headlight based on the sampled voltage.

[0039] Further, the microcontroller module 300 includes a microcontroller U5, a crystal oscillator X1, a first oscillation capacitor C3, a second oscillation capacitor C4, a reset resistor R3, a reset capacitor C5, and a decoupling capacitor C6; the power supply terminal of the microcontroller U5 is connected to the regulated output terminal of the power supply module 100, and the ground terminal of the microcontroller U5 is grounded; the crystal oscillator X1 is connected between the two oscillation terminals of the microcontroller U5, and the first oscillation capacitor C3 and the second oscillation capacitor C4 are respectively connected between the corresponding oscillation terminal and the ground terminal. The reset resistor R3 is connected between the regulated output terminal and the reset terminal of the microcontroller U5; the reset capacitor C5 is connected between the reset terminal of the microcontroller U5 and the ground terminal; and the decoupling capacitor C6 is connected between the power supply terminal and the ground terminal of the microcontroller U5. The fan control terminal, fan status detection terminal, dimming control terminal, and over-temperature control terminal of the microcontroller U5 are respectively connected to the fan drive module 400, the fan self-test module 500, the LED constant current drive module 600, and the over-temperature protection module 700.

[0040] In this embodiment, as Figure 4 The circuit diagram of a microcontroller module shown is illustrated below. Microcontroller U5 is an SH8F5725 microcontroller. Pin 1 is the power supply terminal and is connected to a 3.3V regulated output, while pin 14 is the ground terminal. Decoupling capacitor C6 is a 100nF capacitor connected between the power supply terminal and the ground terminal of microcontroller U5 to filter out power supply interference and stabilize the operating voltage of microcontroller U5.

[0041] Crystal oscillator X1 is an 8MHz crystal oscillator and is connected between pins 2 and 3 of microcontroller U5. The first oscillation capacitor C3 and the second oscillation capacitor C4 are both 22pF capacitors, connected between the two ends of crystal oscillator X1 and the ground terminal, respectively, to form the clock signal required for the operation of microcontroller U5.

[0042] The reset resistor R3 is a 10kΩ resistor, connected between the 3.3V regulated output terminal and pin 4 of the microcontroller U5; the reset capacitor C5 is a 100nF capacitor, connected between pin 4 of the microcontroller U5 and the ground terminal, so as to generate a reset signal during power-on and enable the microcontroller U5 to enter the predetermined initial state.

[0043] Pin 8 of the microcontroller U5 receives a temperature sampling signal via the temperature sampling node NET_ADC_TEMP. Pin 5 outputs a fan control signal to the fan driver module 400 via the fan control terminal FAN_CTRL. Pin 11 receives a fan status detection signal via the fan status detection terminal FAN_CHECK_N. Pin 6 outputs a dimming control signal via the dimming control terminal LED_PWM. Pin 7 outputs an over-temperature control signal to the over-temperature protection module 700 via the over-temperature control terminal OVERTEMP_CTRL. The microcontroller U5 controls the start, stop, and speed of the cooling fan based on the temperature sampling signal and the fan status detection signal, and adjusts the output power of the LED light source when the temperature is too high or the cooling fan is malfunctioning.

[0044] Further, the fan drive module 400 includes a fan connector U9, a P-channel MOSFET Q1, a first transistor Q2, a gate pull-up resistor R11, and a base limiting current resistor R12. The source of the P-channel MOSFET Q1 is connected to the protected power supply terminal of the power module 100, the drain of the P-channel MOSFET Q1 is connected to the first pin of the fan connector U9, and the second pin of the fan connector U9 is connected to the fan self-test module 500. The gate pull-up resistor R11 is connected between the source and the gate of the P-channel MOSFET Q1. The collector of the first transistor Q2 is connected to the gate of the P-channel MOSFET Q1, the emitter of the first transistor Q2 is grounded, and the base of the first transistor Q2 is connected to the fan control terminal of the microcontroller module 300 through the base limiting current resistor R12, so as to control the on / off state of the P-channel MOSFET Q1 according to the fan control signal.

[0045] In this embodiment, as Figure 5 The schematic diagram of the fan and its self-test circuit is shown below. The P-channel MOSFET Q1 is an AO3401 type MOSFET, and the first transistor Q2 is an S8050 type transistor. The source of the P-channel MOSFET Q1 is connected to the protected power supply terminal VIN_FUSED, and the drain is connected to pin 1 of the fan connector U9 to supply power to the positive terminal of the cooling fan. Pin 2 of the fan connector U9 is connected to the fan self-test module 500.

[0046] The fan control signal FAN_CTRL output by microcontroller U5 is input to the base of the first transistor Q2 via a 1kΩ base-limiting current resistor R12. The emitter of the first transistor Q2 is grounded, and its collector is connected to the gate of the P-channel MOSFET Q1. A 10kΩ gate pull-up resistor R11 is connected between the gate and source of the P-channel MOSFET Q1 to pull up the gate voltage of the P-channel MOSFET Q1 to the protected power supply terminal VIN_FUSED when the first transistor Q2 is turned off.

[0047] When the fan control signal FAN_CTRL turns on the first transistor Q2, the gate voltage of the P-channel MOSFET Q1 is pulled low, and Q1 turns on to supply power to the cooling fan. When the first transistor Q2 turns off, the gate pull-up resistor R11 turns off Q1, thus stopping the power supply to the cooling fan. The microcontroller U5 can adjust the on / off time ratio of the P-channel MOSFET Q1 by changing the duty cycle of the fan control signal FAN_CTRL, thereby adjusting the speed of the cooling fan.

[0048] Furthermore, the fan self-test module 500 includes a current sampling resistor R5, a detection resistor R6, a second transistor Q3, and a detection filter capacitor C7. The current sampling resistor R5 is connected between the second pin of the fan connector U9 and the ground terminal, and the detection resistor R6 is connected between the second pin of the fan connector U9 and the base of the second transistor Q3. The emitter of the second transistor Q3 is grounded, and the collector of the second transistor Q3 is connected to the fan status detection terminal of the microcontroller module 300. The detection filter capacitor C7 is connected between the collector of the second transistor Q3 and the ground terminal, so that the second transistor Q3 changes its conduction state according to the sampling voltage formed across the current sampling resistor R5 and outputs the fan status detection signal.

[0049] In this embodiment, as Figure 5 The schematic diagram of the fan and its self-test circuit is shown below. The current sampling resistor R5 is a 4.7Ω resistor and is connected between pin 2 of the fan connector U9 and the ground terminal. When the cooling fan is running, the operating current flows to the ground terminal through pin 2 of the fan connector U9 and the current sampling resistor R5, so that the negative terminal FAN_NEG of the fan forms a sampling voltage relative to the ground terminal.

[0050] The sensing resistor R6 is a 10kΩ resistor, connected between the negative terminal of the fan (FAN_NEG) and the base of the second transistor Q3. The second transistor Q3 is an S8050 type transistor, with its emitter grounded and its collector connected to the microcontroller U5 through the fan status sensing node (FAN_CHECK_N). When the sampling voltage reaches the conduction condition of the second transistor Q3, Q3 conducts and pulls the fan status sensing node (FAN_CHECK_N) low; when the cooling fan does not generate operating current or the operating current is lower than the corresponding threshold, the second transistor Q3 is turned off.

[0051] The detection filter capacitor C7 is a 100nF capacitor connected between the fan status detection node FAN_CHECK_N and the ground terminal to filter out transient interference generated during the start-up, shutdown, and speed adjustment of the cooling fan. During the power-on self-test, the microcontroller U5 controls the operation of the cooling fan and determines whether the power supply circuit of the cooling fan is generating operating current based on the voltage level of the fan status detection node FAN_CHECK_N.

[0052] Further, the LED constant current driving module 600 includes a constant current driving chip U7, a driving freewheeling diode D3, a driving filter capacitor C8, a current setting resistor R7, a first LED LED2, a second LED LED4, a third LED LED6, and a driving inductor L3; the power supply terminal of the constant current driving chip U7 is connected to the protected power supply terminal of the power module 100, and the driving filter capacitor C8 is connected between the power supply terminal and the ground terminal of the constant current driving chip U7; the driving freewheeling diode D3 is connected between the switching terminal of the constant current driving chip U7 and the protected power supply terminal, and the current setting resistor R7 is connected between the protected power supply terminal and the current detection terminal of the constant current driving chip U7; the first LED LED2, the... The second light-emitting diode LED4 and the third light-emitting diode LED6 are connected in series between the current detection terminal of the constant current driving chip U7 and the driving inductor L3. The other end of the driving inductor L3 is connected to the switching terminal of the constant current driving chip U7. The over-temperature protection module 700 includes a dimming input resistor R8, a third transistor Q4, and an over-temperature control resistor R9. The dimming input resistor R8 is connected between the dimming control terminal of the microcontroller module 300 and the dimming terminal of the constant current driving chip U7. The collector of the third transistor Q4 is connected to the dimming terminal of the constant current driving chip U7, the emitter of the third transistor Q4 is grounded, and the base of the third transistor Q4 is connected to the over-temperature control terminal of the microcontroller module 300 through the over-temperature control resistor R9.

[0053] In this embodiment, as Figure 6 The schematic diagram of the LED constant current drive module circuit is shown below. The constant current drive chip U7 is a PT4115B89E type. Its pin 5 is the power supply terminal and is connected to the protected power supply terminal VIN_FUSED, and its pin 2 is grounded. The drive filter capacitor C8 is a 10μF capacitor. Its positive terminal is connected to the protected power supply terminal VIN_FUSED, and its negative terminal is grounded. It is used to filter out ripple in the input voltage.

[0054] The driving freewheeling diode D3 is an SS34 Schottky diode, with its anode connected to pin 1 of the constant current driving chip U7 and its cathode connected to the protected power supply terminal VIN_FUSED. The current setting resistor R7 is a 330mΩ resistor, connected between the protected power supply terminal VIN_FUSED and pin 4 of the constant current driving chip U7 to set the constant current driving current of the LED light source.

[0055] The first LED (LED2), the second LED (LED4), and the third LED (LED6) are connected in series and, together with the 68μH driving inductor L3, are connected between pin 4 and pin 1 of the constant current driving chip U7. The constant current driving chip U7 controls the switching state of pin 1 to enable the driving inductor L3 to store and release energy, and forms a freewheeling path through the driving freewheeling diode D3, thereby maintaining a stable driving current through each LED.

[0056] The dimming control signal LED_PWM is transmitted to pin 3 of the constant current driver chip U7 via the dimming input resistor R8 to adjust the output power of the LED light source by changing the duty cycle of the LED_PWM signal. The third transistor Q4 is an S8050 type transistor, with its collector connected to pin 3 of the constant current driver chip U7, its emitter grounded, and its base receiving the over-temperature control signal OVERTEMP_CTRL via the over-temperature control resistor R9. When the third transistor Q4 is turned on, pin 3 of the constant current driver chip U7 is pulled low, thereby limiting or turning off the output of the LED constant current driver module 600.

[0057] This embodiment also provides an intelligent temperature control start-stop method applied to LED vehicle lights, comprising: responding to the power-on of the LED vehicle light, controlling a cooling fan to operate within a preset self-test duration; acquiring a fan status detection signal during the operation of the cooling fan, determining whether the cooling fan has an operational abnormality based on the fan status detection signal, and reducing the output power of the LED light source to a first protection power when the cooling fan has an operational abnormality; acquiring a temperature sampling signal of the LED vehicle light, determining the corresponding current temperature based on the temperature sampling signal; determining a target operating state of the cooling fan based on the temperature range of the current temperature, and determining the target operating state according to a downgrading temperature threshold below the corresponding upgrading temperature threshold when the current temperature drops; outputting a fan control signal according to the target operating state to control the cooling fan to stop or operate at a corresponding speed; comparing the current temperature with an over-temperature protection threshold, reducing the output power of the LED light source to a second protection power when the current temperature is higher than the over-temperature protection threshold, and restoring the output power of the LED light source when the current temperature drops below an over-temperature recovery threshold, wherein the over-temperature recovery threshold is lower than the over-temperature protection threshold.

[0058] In this embodiment, the aforementioned intelligent temperature control start / stop method is executed by the microcontroller U5. After the LED headlights are powered on, the microcontroller U5 controls the cooling fan to run for 3 seconds via the fan control signal FAN_CTRL, and during this period reads the fan status detection signal FAN_CHECK_N to determine whether the power supply circuit of the cooling fan is generating operating current.

[0059] When the fan status detection signal FAN_CHECK_N is not at the preset level, the microcontroller U5 determines that the cooling fan is malfunctioning and reduces the output power of the LED light source to 50% of the rated output power via the dimming control signal LED_PWM as the first protection power. After completing the power-on self-test, the microcontroller U5 continues to perform temperature monitoring.

[0060] The microcontroller U5 acquires the voltage of the temperature sampling node NET_ADC_TEMP and determines the current temperature based on the temperature-resistance relationship of the negative temperature coefficient thermistor R13. When the current temperature is below 55℃, the cooling fan is stopped; when the current temperature is between 55℃ and 70℃, the cooling fan runs at a low speed of 3000 rpm; when the current temperature is between 70℃ and 85℃, the cooling fan runs at a medium speed of 5000 rpm; and when the current temperature is above 85℃, the cooling fan runs at a high speed of 7000 rpm.

[0061] The microcontroller U5 controls the cooling fan to run at the corresponding speed by changing the duty cycle of the fan control signal FAN_CTRL. As the current temperature drops, the temperature threshold for each speed reduction is set 5°C lower than the corresponding temperature threshold for the speed increase. That is, after high-speed operation, when the temperature drops to 80°C, it switches to medium speed; after medium speed operation, when the temperature drops to 65°C, it switches to low speed; and after low speed operation, when the temperature drops to 50°C, the cooling fan stops. This avoids the cooling fan frequently switching between speeds near the temperature thresholds.

[0062] The microcontroller U5 also compares the current temperature with the 95°C over-temperature protection threshold. When the current temperature is higher than 95°C, the output power of the LED light source is reduced to 70% of the rated output power as a second protection power through the dimming control signal LED_PWM or the over-temperature control signal OVERTEMP_CTRL; when the current temperature drops below 85°C, the normal output power of the LED light source is restored.

[0063] After completing the above control, the microcontroller U5 reacquires the temperature sampling signal every 5 seconds and repeats the temperature range judgment, cooling fan control and over-temperature protection.

[0064] Furthermore, the preset self-test duration is 3 seconds; within the preset self-test duration, the fan status detection signal is generated based on the operating current flowing through the cooling fan; when the operating current is not within the preset current range, it is determined that the cooling fan is stalled or the current is abnormal, and the output power of the light-emitting diode light source is reduced to 50% of the rated output power.

[0065] In this embodiment, after the LED headlights are powered on, the microcontroller U5 controls the cooling fan to run continuously for 3 seconds via the fan control signal FAN_CTRL. During these 3 seconds, the operating current of the cooling fan flows through the current sampling resistor R5, forming a sampling voltage at the fan's negative terminal FAN_NEG. The second transistor Q3 changes its conduction state according to the sampling voltage, thereby outputting a fan status detection signal to the microcontroller U5 through the fan status detection node FAN_CHECK_N.

[0066] The aforementioned preset current range is pre-set based on the rated operating current of the cooling fan and the allowable current fluctuation range. The microcontroller U5 determines whether the cooling fan is operating normally based on whether the fan status detection signal is within the preset state corresponding to the normal operating current. When the cooling fan's operating current is outside the preset current range, the microcontroller U5 determines that the cooling fan is stalled or experiencing an abnormal current.

[0067] When a malfunction is detected in the cooling fan, the microcontroller U5 reduces the duty cycle of the dimming control signal LED_PWM, causing the LED constant current drive module 600 to reduce the output power of the LED light source to 50% of the rated output power, thereby reducing the heat generated by the LED light source.

[0068] Further, determining the target operating state of the cooling fan based on the temperature range of the current temperature includes: when the current temperature is below 55°C, determining the target operating state as a stopped state; when the current temperature is between 55°C and 70°C, determining the target operating state as a low-speed operating state, with a speed of 3000 rpm; when the current temperature is between 70°C and 85°C, determining the target operating state as a medium-speed operating state, with a speed of 5000 rpm; when the current temperature is above 85°C, determining the target operating state as a high-speed operating state, with a speed of 7000 rpm; when the current temperature decreases, setting each down-level temperature threshold to be 5°C lower than the corresponding up-level temperature threshold; setting the over-temperature protection threshold to 95°C; when the current temperature is above 95°C, reducing the output power of the LED light source to 70% of its rated output power, and restoring the output power of the LED light source when the current temperature drops below 85°C.

[0069] In this embodiment, the microcontroller U5 determines the current temperature based on the sampling voltage of the temperature sampling node NET_ADC_TEMP, and compares the current temperature with the pre-stored temperature range to determine the target operating state of the cooling fan.

[0070] When the current temperature is below 55℃, the microcontroller U5 stops the cooling fan; when the current temperature reaches 55℃ but is below 70℃, it outputs a fan control signal FAN_CTRL corresponding to 3000 rpm; when the current temperature reaches 70℃ but is not higher than 85℃, it outputs a fan control signal FAN_CTRL corresponding to 5000 rpm; and when the current temperature is above 85℃, it outputs a fan control signal FAN_CTRL corresponding to 7000 rpm. The microcontroller U5 adjusts the duty cycle of the fan control signal FAN_CTRL to make the cooling fan run at the target speed.

[0071] When the current temperature drops, the microcontroller U5 employs hysteresis downshift control. When the cooling fan is running at high speed, it switches to medium speed when the current temperature drops to 80℃; when the cooling fan is running at medium speed, it switches to low speed when the current temperature drops to 65℃; and when the cooling fan is running at low speed, it stops when the current temperature drops to 50℃, thus avoiding frequent switching of the cooling fan near the temperature threshold.

[0072] When the current temperature is above 95℃, the microcontroller U5 reduces the duty cycle of the dimming control signal LED_PWM, reducing the output power of the LED light source to 70% of the rated output power; when the current temperature drops below 85℃, the microcontroller U5 restores the normal duty cycle of the dimming control signal LED_PWM, restoring the normal output power of the LED light source.

[0073] The above is only used to illustrate the technical solution of the present invention and is not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. An intelligent temperature-controlled start-stop circuit, applied to LED vehicle lights, characterized in that, It includes a power supply module (100), a temperature sensor module (200), a microcontroller module (300), a fan drive module (400), a fan self-test module (500), an LED constant current drive module (600), and an over-temperature protection module (700). The power supply module (100) is electrically connected to the temperature sensor module (200), the microcontroller module (300), the fan drive module (400), and the LED constant current drive module (600), respectively. The power supply module (100) has the function of protecting and stepping down the input power supply and outputting the corresponding working voltage. The temperature sensor module (200) is electrically connected to the microcontroller module (300), and the temperature sensor module (200) has the function of detecting the temperature of the LED vehicle light and outputting a temperature sampling signal; The microcontroller module (300) is electrically connected to the fan drive module (400), the fan self-test module (500), the LED constant current drive module (600), and the over-temperature protection module (700), respectively. The microcontroller module (300) has the functions of controlling the start and stop and speed of the cooling fan according to the temperature sampling signal, judging the operating status of the cooling fan according to the fan status detection signal, and controlling the output power of the LED. The fan drive module (400) is connected between the power supply module (100), the microcontroller module (300) and the cooling fan. The fan drive module (400) has the function of connecting or disconnecting the power supply path of the cooling fan according to the fan control signal output by the microcontroller module (300) and adjusting the speed of the cooling fan. The fan self-test module (500) is connected between the cooling fan and the microcontroller module (300). The fan self-test module (500) has the function of detecting the current flowing through the cooling fan and outputting the fan status detection signal to the microcontroller module (300). The LED constant current driving module (600) is connected between the power supply module (100), the microcontroller module (300) and the LED light source. The LED constant current driving module (600) has the function of outputting a constant driving current to the LED light source and adjusting the output power of the LED light source according to the dimming control signal. The over-temperature protection module (700) is connected between the microcontroller module (300) and the LED constant current drive module (600). The over-temperature protection module (700) has the function of limiting the output of the LED constant current drive module (600) according to the over-temperature control signal output by the microcontroller module (300).

2. The intelligent temperature control start / stop circuit according to claim 1, characterized in that, The power module (100) includes a power input terminal U3, a fuse element U1, an input capacitor C1, a step-down chip U2, an energy storage inductor L1, a freewheeling diode D1, a first feedback resistor R1, a second feedback resistor R2, an output capacitor C2, and a power output terminal U4. The first pin of the power input terminal U3 is connected to the input protection node through the fuse element U1, and the second pin of the power input terminal U3 is grounded; The input capacitor C1 is connected between the input protection node and the ground terminal, and the input terminal of the step-down chip U2 is connected to the input protection node; The switching terminal of the step-down chip U2 is connected to the regulated output node through the energy storage inductor L1, and the freewheeling diode D1 is connected between the switching terminal and the ground terminal of the step-down chip U2. The first feedback resistor R1 and the second feedback resistor R2 are connected in series between the regulated output node and the ground terminal, and the connection node of the first feedback resistor R1 and the second feedback resistor R2 is connected to the feedback terminal of the step-down chip U2. The output capacitor C2 is connected between the regulated output node and the ground terminal. The first pin of the power output terminal U4 is connected to the regulated output node, and the second pin of the power output terminal U4 is grounded.

3. The intelligent temperature control start / stop circuit according to claim 1, characterized in that, The temperature sensor module (200) includes a negative temperature coefficient thermistor R13, a voltage divider resistor R14, and a filter capacitor C10; The negative temperature coefficient thermistor R13 is connected between the regulated output node and the temperature sampling node of the power module (100); The voltage divider resistor R14 is connected between the temperature sampling node and the ground terminal, the filter capacitor C10 is connected in parallel with the voltage divider resistor R14, and the temperature sampling node is connected to the temperature sampling terminal of the microcontroller module (300).

4. The intelligent temperature control start / stop circuit according to claim 1, characterized in that, The microcontroller module (300) includes a microcontroller U5, a crystal oscillator X1, a first oscillation capacitor C3, a second oscillation capacitor C4, a reset resistor R3, a reset capacitor C5, and a decoupling capacitor C6. The power supply terminal of the microcontroller U5 is connected to the regulated output node of the power module (100), and the ground terminal of the microcontroller U5 is grounded. The crystal oscillator X1 is connected between the two oscillation terminals of the microcontroller U5, and the first oscillation capacitor C3 and the second oscillation capacitor C4 are respectively connected between the corresponding oscillation terminal and the ground terminal; The reset resistor R3 is connected between the regulated output node and the reset terminal of the microcontroller U5, the reset capacitor C5 is connected between the reset terminal of the microcontroller U5 and the ground terminal, and the decoupling capacitor C6 is connected between the power supply terminal and the ground terminal of the microcontroller U5. The fan control terminal, fan status detection terminal, dimming control terminal, and over-temperature control terminal of the microcontroller U5 are respectively connected to the fan drive module (400), the fan self-test module (500), the LED constant current drive module (600), and the over-temperature protection module (700).

5. The intelligent temperature control start / stop circuit according to claim 1, characterized in that, The fan drive module (400) includes a fan connector U9, a P-channel field-effect transistor Q1, a first transistor Q2, a gate pull-up resistor R11, and a base limiting current resistor R12. The source of the P-channel MOSFET Q1 is connected to the input protection node of the power module (100), the drain of the P-channel MOSFET Q1 is connected to the first pin of the fan connector U9, and the second pin of the fan connector U9 is connected to the fan self-test module (500). The gate pull-up resistor R11 is connected between the source and gate of the P-channel field-effect transistor Q1; The collector of the first transistor Q2 is connected to the gate of the P-channel field-effect transistor Q1, the emitter of the first transistor Q2 is grounded, and the base of the first transistor Q2 is connected to the fan control terminal of the microcontroller module (300) through the base current limiting resistor R12, so as to control the on / off state of the P-channel field-effect transistor Q1 according to the fan control signal.

6. The intelligent temperature control start / stop circuit according to claim 5, characterized in that, The fan self-test module (500) includes a current sampling resistor R5, a detection resistor R6, a second transistor Q3, and a detection filter capacitor C7; The current sampling resistor R5 is connected between the second pin of the fan connector U9 and the ground terminal, and the detection resistor R6 is connected between the second pin of the fan connector U9 and the base of the second transistor Q3; The emitter of the second transistor Q3 is grounded, and the collector of the second transistor Q3 is connected to the fan status detection terminal of the microcontroller module (300). The detection filter capacitor C7 is connected between the collector of the second transistor Q3 and the ground terminal, so that the second transistor Q3 changes its conduction state according to the sampling voltage formed across the current sampling resistor R5 and outputs the fan status detection signal.

7. The intelligent temperature control start / stop circuit according to claim 1, characterized in that, The LED constant current drive module (600) includes a constant current drive chip U7, a drive freewheeling diode D3, a drive filter capacitor C8, a current setting resistor R7, a first LED LED2, a second LED LED4, a third LED LED6, and a drive inductor L3. The power supply terminal of the constant current drive chip U7 is connected to the input protection node of the power module (100), and the drive filter capacitor C8 is connected between the power supply terminal and the ground terminal of the constant current drive chip U7. The driving freewheeling diode D3 is connected between the switching terminal of the constant current driving chip U7 and the input protection node, and the current setting resistor R7 is connected between the input protection node and the current detection terminal of the constant current driving chip U7. The first light-emitting diode LED2, the second light-emitting diode LED4, and the third light-emitting diode LED6 are connected in series between the current detection terminal of the constant current driving chip U7 and the driving inductor L3, and the other end of the driving inductor L3 is connected to the switching terminal of the constant current driving chip U7. The over-temperature protection module (700) includes a dimming input resistor R8, a third transistor Q4, and an over-temperature control resistor R9. The dimming input resistor R8 is connected between the dimming control terminal of the microcontroller module (300) and the dimming terminal of the constant current drive chip U7. The collector of the third transistor Q4 is connected to the dimming terminal of the constant current drive chip U7. The emitter of the third transistor Q4 is grounded. The base of the third transistor Q4 is connected to the over-temperature control terminal of the microcontroller module (300) through the over-temperature control resistor R9.

8. A smart temperature-controlled start-stop method, applied to LED vehicle lights, characterized in that, include: In response to the power-on of the LED headlights, the cooling fan is controlled to run within a preset self-test duration; During the operation of the cooling fan, a fan status detection signal is acquired, and the operation of the cooling fan is determined based on the fan status detection signal. If the cooling fan is found to be operating abnormally, the output power of the light-emitting diode light source is reduced to the first protection power. Acquire the temperature sampling signal of the LED vehicle light, and determine the corresponding current temperature based on the temperature sampling signal; The target operating state of the cooling fan is determined based on the temperature range of the current temperature, and when the current temperature drops, the target operating state is determined according to the down-level temperature threshold that is lower than the corresponding up-level temperature threshold. Based on the target operating state, a fan control signal is output to control the cooling fan to stop or operate at a corresponding speed; The current temperature is compared with the over-temperature protection threshold. When the current temperature is higher than the over-temperature protection threshold, the output power of the LED light source is reduced to a second protection power. When the current temperature is reduced to below the over-temperature recovery threshold, the output power of the LED light source is restored. The over-temperature recovery threshold is lower than the over-temperature protection threshold.

9. The intelligent temperature control start / stop method according to claim 8, characterized in that, The preset self-test duration is 3 seconds; Within the preset self-test duration, a fan status detection signal is generated based on the operating current flowing through the cooling fan. When the operating current is not within the preset current range, it is determined that the cooling fan is stalled or the current is abnormal, and the output power of the light-emitting diode light source is reduced to 50% of the rated output power.

10. The intelligent temperature control start / stop method according to claim 8, characterized in that, Determining the target operating state of the cooling fan based on the temperature range of the current temperature includes: When the current temperature is below 55°C, the target operating state is determined to be a stopped state; When the current temperature is between 55°C and 70°C, the target operating state is determined to be a low-speed operating state, and the speed corresponding to the low-speed operating state is 3000 rpm. When the current temperature is between 70°C and 85°C, the target operating state is determined to be a medium-speed operating state, and the speed corresponding to the medium-speed operating state is 5000 rpm. When the current temperature is higher than 85°C, the target operating state is determined to be a high-speed operating state, and the speed corresponding to the high-speed operating state is 7000 rpm. When the current temperature drops, each of the downgrade temperature thresholds is set to be 5°C lower than the corresponding upgrade temperature threshold. The over-temperature protection threshold is set to 95°C. When the current temperature is higher than 95°C, the output power of the LED light source is reduced to 70% of the rated output power, and the output power of the LED light source is restored when the current temperature drops below 85°C.

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