Power supply conversion device of vehicle lighting system

Abstract

The utility model provides a power supply conversion device for a vehicle lighting system. The power supply conversion device comprises an input filter circuit, a BUCK step-down circuit, a rectification filter circuit, an output detection feedback circuit, a PWM drive circuit and a starting circuit. The input filter circuit receives a 110V direct-current power supply, filters the 110V direct-current power supply and then transmits the electric energy to the BUCK voltage reduction circuit, and the BUCK voltage reduction circuit reduces the voltage to the voltage suitable for a lighting system. The rectification filter circuit carries out rectification and smoothing processing on the pulsating voltage output by the BUCK circuit, and it is ensured that the output voltage is stable. The output detection feedback circuit monitors the output voltage and transmits a feedback signal to the PWM controller, and the duty ratio of the PWM signal is adjusted, so that the working state of the BUCK step-down circuit is controlled, and the stability of the output voltage is ensured. According to the utility model, high-efficiency voltage conversion is realized, the power supply stability of the vehicle lighting system is ensured through an accurate feedback mechanism, and the vehicle lighting system has relatively high practicability and stability.

Description

TECHNICAL FIELD

[0001] The utility model belongs to power conversion technical field, concretely relates to a vehicle lighting system power supply conversion device. BACKGROUND

[0002] With the continuous development of automobile electronic technology, the requirement for power management in vehicles is getting higher and higher, especially the stability and reliability of power supply for vehicle lighting system are strict. The traditional vehicle lighting system mostly depends on the vehicle battery to provide power, however, with the limitation of battery technology, especially the fluctuation of battery voltage, it may cause the performance of lighting system unstable, and even affect the driving safety. In addition, there are different voltage level requirements in the electrical system of the automobile, especially the vehicle lighting system often needs lower stable DC voltage power supply, so a high-efficiency and stable power conversion device is needed.

[0003] In the traditional power conversion technology, the common DC-DC step-down converter (such as BUCK circuit) is widely used to convert higher input voltage into appropriate output voltage. However, there are some problems in the existing technology, such as low efficiency, slow response, unstable output voltage, etc., which seriously affect the stability and reliability of the lighting system, especially in the case of dynamic load change, the control accuracy and response speed of the step-down circuit are particularly important.

[0004] In order to meet the demand of stable voltage and high-efficiency power conversion for vehicle lighting system, some step-down circuits based on PWM control have appeared in the prior art, but there are still the following shortcomings:

[0005] Efficiency problem: the traditional power conversion device often has low efficiency when dealing with high input voltage (such as 110V DC power supply), which leads to large system heat, and further affects the long-term stability of the power supply and the use experience of the vehicle.

[0006] Feedback control lag: the feedback control system of some power conversion devices responds slowly, which cannot quickly respond to load changes, resulting in large output voltage fluctuation and affecting the normal work of lighting equipment.

[0007] Complexity and poor stability: some power conversion devices in the prior art have complex structure, too many control chips and driving circuits are used, which increases the complexity and cost of the system, and in some special working conditions, the system may be unstable or unable to start.

[0008] Therefore, how to provide a simple structure, high efficiency, and stable work in the vehicle lighting system and meet various working conditions of power conversion device has become a problem to be solved in power management technology. UTILITY MODEL CONTENT

[0009] The utility model discloses a vehicle lighting system power supply conversion device can overcome the defects of prior art.

[0010] The utility model discloses a vehicle lighting system power supply conversion device can overcome the defects of prior art.

[0011] The utility model provides a vehicle lighting system power supply conversion device, including input filter circuit, BUCK voltage reducing circuit, rectifier filter circuit, output detection feedback circuit, PWM drive circuit, starting circuit, input filter circuit input end is connected to 110V direct current power supply, and output end is connected with BUCK voltage reducing circuit input end, the input end of starting circuit is connected with BUCK voltage reducing circuit output end, and output end is connected with PWM drive circuit, BUCK voltage reducing circuit output end is connected with rectifier filter circuit input end, rectifier filter circuit output end is connected with output detection feedback circuit input end, and output detection feedback circuit output end is connected with PWM drive circuit input end, PWM drive circuit output end is connected with BUCK voltage reducing circuit.

[0012] Further, the rectifier filter circuit includes three parallel first filter capacitors, second filter capacitors, third filter capacitors, four parallel jumpers; the BUCK voltage reducing circuit output end is connected with the first filter capacitor, the second filter capacitor, the third filter capacitor and the jumper respectively.

[0013] Further, the output detection feedback circuit includes a dual-channel operational amplifier, the 2 pin of the dual-channel operational amplifier is connected with the BUCK voltage reducing circuit output end, and the 3 pin of the dual-channel operational amplifier is connected with the output end of the rectifier filter circuit.

[0014] Further, the PWM drive circuit includes a PWM controller, a half-bridge driver, first, second, third resistors, first and second capacitors, fourth, fifth, sixth, seventh resistors, and NPN and PNP transistors.

[0015] Further, the 1 pin of the dual operational amplifier is connected with the 9 pin of the PWM controller, the output end of the rectification filter circuit is connected with the 16 pin of the PWM controller, the 2 pin of the PWM controller is connected with the first resistor through the first resistor, the 6 pin of the PWM controller is connected with the first resistor, the second resistor and the third resistor in series, the 7 pin of the PWM controller is connected with the first resistor, the second resistor and the first capacitor in series, the 8 pin of the PWM controller is grounded, the 12 pin, the 13 pin and the 15 pin of the PWM controller are connected with the output end of the starting circuit, the 11 pin of the PWM controller is connected with the 1 pin of the half-bridge driver, and the 14 pin of the PWM controller is connected with the 1 pin of the half-bridge driver through the third resistor and the fifth resistor in series.

[0016] Further, the 2 pin of the half-bridge driver is connected with the output end of the starting circuit, the 3 pin of the half-bridge driver is grounded through the sixth resistor and the second capacitor in parallel, the 4 pin of the half-bridge driver is grounded, the 8 pin of the half-bridge driver is connected with the collector of the NPN triode, the 7 pin of the half-bridge driver is connected with the base of the NPN triode and the base of the PNP triode through the seventh resistor respectively, and the 6 pin of the half-bridge driver is connected with the collector of the PNP triode.

[0017] Further, the BUCK voltage reduction circuit comprises the first N-type MOS tube, the second N-type MOS tube, the third N-type MOS tube and the fourth N-type MOS tube in parallel.

[0018] Further, the output end of the input filter circuit is connected with the drain of the first N-type MOS tube, the drain of the second N-type MOS tube, the drain of the third N-type MOS tube and the drain of the fourth N-type MOS tube respectively, the emitter of the NPN triode is connected with the gate of the first N-type MOS tube, the gate of the second N-type MOS tube, the gate of the third N-type MOS tube and the gate of the fourth N-type MOS tube respectively, and the source of the first N-type MOS tube, the source of the second N-type MOS tube, the source of the third N-type MOS tube and the source of the fourth N-type MOS tube are connected with the input end of the rectification filter circuit and the 6 pin of the half-bridge driver respectively.

[0019] Further, the starting circuit comprises a voltage stabilizer, a first diode, a fourth filter capacitor, a third capacitor and a fourth capacitor.

[0020] Further, the 1 pin of the voltage stabilizer is connected with the output end of the BUCK voltage reduction circuit, the 2 pin of the voltage stabilizer is grounded, the 3 pin of the voltage stabilizer is connected with the anode of the first diode, and the cathode of the first diode is connected with the fourth filter capacitor, the third capacitor, the fourth capacitor and the PWM driving circuit respectively.

[0021] Compared with the prior art, the utility model has the following advantages:

[0022] (1) The utility model discloses a BUCK voltage reduction circuit is used, high input voltage (such as 110V DC power supply) is converted into the low output voltage required, adopts the N type MOS pipe of parallel connection and the PWM drive circuit of accurate control, improves the power conversion efficiency, reduces the energy loss. This design effectively improves the efficiency of power conversion, reduces the heat, prolongs the service life of system, guarantees the stability of vehicle lighting system.

[0023] (2) By using LM2903DR dual-channel operational amplifier as output detection feedback circuit, the utility model discloses can accurately monitor and adjust the output voltage of BUCK voltage reduction circuit. Operational amplifier compares with the voltage of rectifier filter circuit, generates feedback signal and transfers to PWM controller (SG2524DR), thereby dynamically adjusts the duty cycle of PWM signal, maintains stable output voltage. This feedback mechanism significantly improves the stability and response speed of power conversion system, ensures that the vehicle lighting system can still maintain stable voltage supply when the load changes.

[0024] (3) The utility model discloses the combination of SG2524DR PWM controller and L6384D013TR half-bridge driver in PWM drive circuit, the former controls the MOS pipe of BUCK voltage reduction circuit through generating accurate PWM signal, and the latter efficiently drives the gate of MOS pipe, ensures the efficient switching of current. This technical combination greatly improves the accuracy of PWM control, reduces switching loss, improves conversion efficiency and the stability of circuit.

[0025] (4) In rectifier filter circuit, three parallel filter capacitors are used, and jumper configuration is combined to ensure the stability of output current. This multiple filtering design can effectively remove high-frequency noise and voltage fluctuation in the power supply, provide more stable output power, adapt to different lighting load requirements, further improve the reliability and stability of the system.

[0026] (5) The utility model discloses a starting circuit containing voltage stabilizer, diode and filter capacitor, which ensures that the system can obtain stable voltage supply during starting. The voltage stabilizer of starting circuit adjusts voltage level to avoid the common problems of starting failure or voltage overshoot in traditional power supply system. This design ensures that the power conversion device can start smoothly in various environments, further improving the reliability of the system.

[0027] (6) The utility model discloses highly integrated chips and modular design in circuit design, reduces the circuit complexity through reasonable arrangement of each circuit module, improves the stability and maintainability of system. Especially by using efficient PWM controller and driver combination, the energy loss in power conversion process is reduced, and the overall efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a device structure diagram of the utility model;

[0029] Figure 2 is a starting circuit diagram of the utility model;

[0030] Figure 3 is a filter circuit diagram of the utility model;

[0031] Figure 4 is a first part diagram of input filter circuit of the utility model;

[0032] Figure 5 is a second part diagram of input filter circuit of the utility model;

[0033] Figure 6 is a BUCK voltage reduction circuit diagram of the utility model;

[0034] Figure 7 is a rectification filter circuit diagram of the utility model;

[0035] Figure 8 is an output circuit diagram of the utility model;

[0036] Figure 9 is an output detection feedback circuit diagram of the utility model;

[0037] Figure 10 is a first part diagram of PWM drive circuit of the utility model;

[0038] Figure 11 is a second part diagram of PWM drive circuit of the utility model;

[0039] In the drawing, reference signs are: C3, first filter capacitor, C4, second filter capacitor, C5, third filter capacitor, R19, first resistance, R20, second resistance, R21, third resistance, C32, first capacitor, R17, fourth resistance, R18, fifth resistance, R23, sixth resistance, C33, second capacitor, R24, seventh resistance, Q13, NPN triode, Q12, PNP triode, Q1, first N type MOS tube, Q3, second N type MOS tube, Q5, third N type MOS tube, Q7, fourth N type MOS tube, Q9, voltage stabilizer, D3A, first diode, C22, fourth filter capacitor, C29, third capacitor, C34, fourth capacitor, U1B, two-way operational amplifier, U2, PWM controller, U3, half bridge driver. DETAILED DESCRIPTION

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present utility model.

[0041] Example 1:

[0042] This embodiment provides a power supply conversion device for a vehicle lighting system, such as... Figure 1 As shown, the circuit includes an input filter circuit, a buck converter circuit, a rectifier filter circuit, an output detection feedback circuit, a PWM drive circuit, and a startup circuit. The input terminal of the input filter circuit is connected to a 110V DC power supply, and its output terminal is connected to the input terminal of the buck converter circuit. The input terminal of the startup circuit is connected to the output terminal of the buck converter circuit, and its output terminal is connected to the PWM drive circuit. The output terminal of the buck converter circuit is connected to the input terminal of the rectifier filter circuit, the output terminal of the rectifier filter circuit is connected to the input terminal of the output detection feedback circuit, the output terminal of the output detection feedback circuit is connected to the input terminal of the PWM drive circuit, and the output terminal of the PWM drive circuit is connected to the buck converter circuit.

[0043] like Figure 2 As shown, the startup circuit includes a voltage regulator, a first diode, a fourth filter capacitor, a third capacitor, and a fourth capacitor. Pin 1 of the voltage regulator is connected to the output of the BUCK step-down circuit, pin 2 is grounded, pin 3 is connected to the anode of the first diode, and the cathode of the first diode is connected to the fourth filter capacitor, the third capacitor, the fourth capacitor, and the PWM drive circuit, respectively.

[0044] Figure 3 The filter circuit in this embodiment has its input terminal connected to the output terminal of the input filter circuit and its output terminal connected to the dual operational amplifier in the output detection feedback circuit. It is used to filter the current output by the input filter circuit and to power the dual operational amplifier.

[0045] Figure 4 Figure 5 This embodiment's input filter circuit's main function is to receive power from a 110V DC power supply and filter out high-frequency noise and voltage fluctuations in the input power. The circuit uses capacitors (such as electrolytic and ceramic capacitors) to filter out noise, ensuring a stable power supply voltage. The filtered voltage is then input to the BUCK step-down circuit's input terminal, initiating the power conversion process.

[0046] Figure 6For the BUCK voltage reduction circuit of the embodiment, it includes first, second, third and fourth N-type MOS transistors connected in parallel, wherein the drain of the MOS transistor is connected to the output of the input filter circuit, the source is connected to the input of the rectifier filter circuit, and the gate is connected to the PWM drive circuit.

[0047] Figure 7 For the rectifier filter circuit of the embodiment, it includes a plurality of parallel filter capacitors, and the output of the BUCK voltage reduction circuit passes through the rectifier filter circuit to smooth the pulsed direct current after rectification and provide a stable direct current source. The rectifier filter circuit includes a plurality of filter capacitors and a jumper, and the purpose is to smooth the pulsed current output by the BUCK voltage reduction circuit and remove high-frequency noise therein.

[0048] The output of the rectifier filter circuit is connected to the output detection feedback circuit (LM2903DR), which detects whether the output voltage of the BUCK voltage reduction circuit is stable. If the output voltage deviates from the preset value, the feedback signal will be sent back to the PWM controller to adjust the duty cycle of the PWM signal.

[0049] Figure 8 For the output circuit of the embodiment, it outputs DC 24V.

[0050] Figure 9 For the output detection feedback circuit of the embodiment, it includes a dual-channel operational amplifier (LM2903DR chip), the 2 pin of the dual-channel operational amplifier is connected to the output of the BUCK voltage reduction circuit, the 3 pin of the dual-channel operational amplifier is connected to the output of the rectifier filter circuit, and the 1 pin is connected to the PWM drive circuit, which is mainly used for detecting and comparing the difference between the output voltage of the BUCK voltage reduction circuit and the output voltage of the rectifier filter circuit. The operational amplifier is connected to the output of the BUCK voltage reduction circuit through its 2 pin (negative input terminal), and the 3 pin (positive input terminal) is connected to the output of the rectifier filter circuit. The 1 pin (output terminal) is connected to the 9 pin (PWM controller input terminal) of the SG2524DR chip, and the duty cycle of the PWM controller is adjusted through the feedback signal to ensure that the system output voltage is stable. The 4 pin (Vcc) is connected to the power supply of the filter circuit, and the 5 pin (ground terminal) is grounded. The working of the LM2903DR chip is to compare the input voltage and the target output voltage, feed back the difference to the PWM controller (SG2524DR), thereby adjusting the output PWM signal to ensure that the output voltage is always stable. Figure 3

[0051] Figure 10 Figure 11 ​For the PWM drive circuit of the embodiment, the PWM drive circuit comprises a PWM controller, a half-bridge driver, a first resistor, a second resistor, a third resistor, a first capacitor, a fourth resistor, a fifth resistor, a sixth resistor, a second capacitor, a seventh resistor, an NPN triode, a PNP triode, the 1 pin of the dual-channel operational amplifier is connected with the 9 pin of the PWM controller, the output end of the rectification filter circuit is connected with the 16 pin of the PWM controller, the 2 pin of the PWM controller is connected with the first resistor, the 6 pin of the PWM controller is connected with the first resistor, the second resistor and the third resistor in series, the 7 pin of the PWM controller is connected with the first resistor, the second resistor and the first capacitor in series, the 8 pin of the PWM controller is grounded, the 12 pin, the 13 pin and the 15 pin of the PWM controller are connected with the output end of the starting circuit, the 11 pin of the PWM controller is connected with the 1 pin of the half-bridge driver, the 14 pin of the PWM controller is connected with the 1 pin of the half-bridge driver through the third resistor and the fifth resistor in series. The 2 pin of the half-bridge driver is connected with the output end of the starting circuit, the 3 pin of the half-bridge driver is grounded through the sixth resistor and the second capacitor in parallel, the 4 pin of the half-bridge driver is grounded, the 8 pin of the half-bridge driver is connected with the collector of the NPN triode, the 7 pin of the half-bridge driver is connected with the base of the NPN triode and the base of the PNP triode through the seventh resistor respectively, the 6 pin of the half-bridge driver is connected with the collector of the PNP triode. The emitter of the NPN triode is connected with the gate of the first N-type MOS tube, the gate of the second N-type MOS tube, the gate of the third N-type MOS tube and the gate of the fourth N-type MOS tube respectively, the source of the first N-type MOS tube, the source of the second N-type MOS tube, the source of the third N-type MOS tube and the source of the fourth N-type MOS tube are connected with the input end of the rectification filter circuit and the 6 pin of the half-bridge driver respectively.

[0052] The core component of the output detection feedback circuit is a dual operational amplifier (LM2903DR). The function of this circuit is to monitor and feedback whether the output voltage of the BUCK step-down circuit meets the preset value, and then adjust the working state of the PWM drive circuit to maintain the stability of the output voltage. Pin 2 (negative input terminal) of LM2903DR is directly connected to the output terminal of the BUCK step-down circuit, receiving the pulsed DC voltage output by the circuit. This voltage is usually a high-frequency pulsed DC current after conversion by the PWM-controlled switching element (such as MOSFET) in the BUCK step-down circuit. Therefore, the output detection feedback circuit needs to detect and adjust it. If the voltage output by the BUCK step-down circuit deviates, the feedback circuit will make corresponding adjustments according to the error. Pin 3 (positive input terminal) of the operational amplifier is connected to the output terminal of the rectifier filter circuit. The rectifier filter circuit smooths the pulsed DC through the rectification and filtering process, making the output voltage more stable and passing it to the positive input terminal for comparison. LM2903DR compares the voltages at the two input terminals and obtains the difference between them.

[0053] The PWM controller is SG2524DR chip, and the half-bridge driver is L6384D013TR chip. The core of the PWM drive circuit is the PWM controller (SG2524DR). Pin 9 of SG2524DR chip 9 is connected to the output terminal (pin 1) of LM2903DR, receiving the feedback signal from the output detection feedback circuit, adjusting the duty cycle of the PWM signal according to the feedback signal, pin 16 of SG2524DR chip is connected to the output terminal of the rectifier filter circuit, used to receive the power voltage signal, pin 6 is grounded through the third resistor, and the duty cycle of the PWM signal is adjusted through the external resistor. This affects the width of the SG2524DR output PWM signal, thereby changing the switching frequency of the BUCK step-down circuit, and adjusting the output voltage, pin 7 is grounded through the first capacitor, and the pin of the external capacitor is connected, used to set the internal oscillation frequency.

[0054] SG2524DR chip according to pin 9 is connected to the output terminal (pin 1) of LM2903DR, receiving the feedback signal from the output detection feedback circuit, adjusting the PWM signal according to the feedback signal, and outputting the PWM signal to the 1 pin of the L6384D013TR chip through the 11 and 13 pins. The L6384D013TR chip outputs the PWM signal output by the SG2524DR chip through the 7 pin, and the 7 pin is connected to the gate of the MOS tube in the BUCK step-down circuit. By controlling the gate of the MOS tube, the conduction of the MOS tube is controlled, thereby controlling the voltage output by the BUCK step-down circuit.

[0055] Example 2:

[0056] The parts not mentioned in this example are the same as in Example 1.

[0057] The core component of the output detection feedback circuit is a dual operational amplifier (LM2903DR). The function of this circuit is to monitor and feedback whether the output voltage of the BUCK step-down circuit meets the preset value, and then adjust the working state of the PWM drive circuit to maintain the stability of the output voltage. Pin 2 (negative input) of LM2903DR is directly connected to the output terminal of the BUCK step-down circuit, receiving the pulsed DC voltage output by the circuit. This voltage is usually a high-frequency pulsed DC current after conversion by the PWM-controlled switching element (such as MOSFET) in the BUCK step-down circuit, so the output detection feedback circuit needs to detect and adjust it. If the output voltage of the BUCK step-down circuit deviates, the feedback circuit will make corresponding adjustments according to the error. Pin 3 (positive input) of the operational amplifier is connected to the output terminal of the rectifier filter circuit. The rectifier filter circuit smooths the pulsed DC through the rectification and filtering process, making the output voltage more stable and passing it to the positive input for comparison. LM2903DR compares the voltages at the two input terminals and obtains the difference between them.

[0058] Pin 1 (output) of LM2903DR outputs a voltage signal, which is determined by the voltage difference at the input and used as an error signal feedback to the PWM controller. This error signal adjusts the working state of the PWM drive circuit, thereby adjusting the output voltage of the BUCK step-down circuit to restore it to the target voltage value. When the operational amplifier detects that the output voltage of the BUCK step-down circuit is too high or too low, the change in the feedback signal will be transmitted to the PWM drive circuit through pin 1, adjusting the duty cycle of the PWM signal.

[0059] The core component of the PWM drive circuit is the PWM controller (SG2524DR). Pin 9 of SG2524DR is connected to the output terminal (pin 1) of LM2903DR, receiving the feedback signal from the output detection feedback circuit. Through this feedback signal, the PWM controller can adjust the duty cycle of the output signal to maintain the stable operation of the BUCK step-down circuit. Specifically, when the output voltage is too high, the feedback signal will adjust the PWM controller to reduce the duty cycle, thereby reducing the output voltage of the BUCK step-down circuit; conversely, when the output voltage is too low, the feedback signal will increase the duty cycle to increase the output voltage. Pin 16 of the PWM controller is connected to the output terminal of the rectifier filter circuit, which is used to provide a reference voltage input to help the controller adjust its operating state and ensure it can respond to voltage changes in a timely manner. Pin 2 is connected to other pins of the PWM controller through a resistor, adjusting the internal frequency, gain, and other parameters of the controller to optimize the generation process of the PWM signal.

[0060] The operation of the PWM drive circuit also includes controlling the switching of the MOSFET through the half-bridge driver. The half-bridge driver (L6384D013TR) is usually connected to pin 11 of the PWM controller, through which it receives the input of the PWM signal and controls the operation of the MOSFET. Pin 1 (IN) of the half-bridge driver receives the PWM modulation signal from the PWM controller, which controls the driving of the MOSFET gate by the half-bridge driver, thereby adjusting the switching of the current. Pin 2 of the half-bridge driver is connected to the output of the start-up circuit, which is responsible for providing the necessary start-up voltage for the driver. Pin 7 of the half-bridge driver controls the gate of the MOSFET, which is connected to the bases of the NPN and PNP transistors through resistors, adjusting the switching state of the MOSFET. The base control signal of the transistors comes from pin 7 of the half-bridge driver, and after connecting through resistors, the switching state of the transistors in turn controls the switching of the MOSFET gate. Pin 6 is connected to the collector of the PNP transistor, and the emitter of the NPN transistor is connected to the gates of multiple N-type MOSFETs to adjust their switching operation and control the current flowing through the BUCK step-down circuit. Through this process, the half-bridge driver ensures that the MOSFET switches as required, thereby adjusting the current size to maintain the stability of the output voltage.

[0061] The working principle of the BUCK step-down circuit is based on the control of the switching element (such as MOSFET) by the PWM signal, thereby achieving the step-down of the input voltage. The circuit contains multiple parallel N-type MOSFETs. The input filter circuit transmits the voltage signal from the DC power supply to the drains of these MOSFETs after filtering. According to the PWM control signal, the gates of these MOSFETs are precisely controlled, and the switching period is adjusted by the PWM controller. Through gate driving, the switching action of the MOSFETs causes the input voltage to be adjusted within a certain switching period, and a stepped DC voltage is output. This pulsed DC voltage enters the rectifier filter circuit and is smoothed into a stable DC voltage by the filter capacitor, ultimately serving as the power supply for the load. The stability of the output voltage depends on the switching accuracy of the BUCK step-down circuit, and the precise PWM control and feedback adjustment mechanism enables the BUCK step-down circuit to automatically adjust the output voltage according to the changes in the load, ensuring the stability of the voltage at the load end.

[0062] The entire system ensures the stability of the voltage through the close cooperation of the output detection feedback circuit, the PWM drive circuit, and the BUCK step-down circuit. Deviation of the output voltage will be detected by the feedback circuit, and the working state of the BUCK step-down circuit will be adjusted through the PWM drive circuit, ultimately ensuring the stable power output required by the vehicle lighting system.

[0063] The above merely describes a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be encompassed within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A power supply conversion device for a vehicle lighting system, characterized by, The input filter circuit, the BUCK voltage reduction circuit, the rectification filter circuit, the output detection feedback circuit, the PWM drive circuit and the starting circuit are connected.

2. The power supply conversion device for a vehicle lighting system according to claim 1, characterized by The rectification filter circuit includes three parallel first filter capacitors, second filter capacitors and third filter capacitors, and four parallel jumpers.

3. The power supply conversion device for a vehicle lighting system according to claim 1, characterized by The output detection feedback circuit includes a double-channel operational amplifier, the 2 pin of which is connected with the output end of the BUCK voltage reduction circuit, and the 3 pin of which is connected with the output end of the rectification filter circuit.

4. The power supply conversion device for a vehicle lighting system according to claim 1, characterized by The PWM drive circuit includes a PWM controller, a half-bridge driver, first, second and third resistors, a first capacitor, fourth, fifth and sixth resistors, a second capacitor, a seventh resistor, an NPN transistor and a PNP transistor.

5. The power supply conversion device for a vehicle lighting system according to claim 3, characterized by The 1 pin of the double-channel operational amplifier is connected with the 9 pin of the PWM controller, the output end of the rectification filter circuit is connected with the 16 pin of the PWM controller, the 2 pin of the PWM controller is connected with the first resistor, the 6 pin of the PWM controller is connected with the first, second and third resistors in series, the 7 pin of the PWM controller is connected with the first, second and first capacitor in series, the 8 pin of the PWM controller is grounded, the 12, 13 and 15 pins of the PWM controller are connected with the output end of the starting circuit, the 11 pin of the PWM controller is connected with the 1 pin of the half-bridge driver, and the 14 pin of the PWM controller is connected with the 1 pin of the half-bridge driver through the third and fifth resistors in series.

6. The power supply conversion device for a vehicle lighting system according to claim 4, characterized by The 2 pin of the half-bridge driver is connected with the output end of the starting circuit, the 3 pin of the half-bridge driver is grounded through the sixth resistor and the second capacitor in parallel, the 4 pin of the half-bridge driver is grounded, the 8 pin of the half-bridge driver is connected with the collector of the NPN transistor, the 7 pin of the half-bridge driver is connected with the base of the NPN transistor and the base of the PNP transistor through the seventh resistor, and the 6 pin of the half-bridge driver is connected with the collector of the PNP transistor.

7. The power supply conversion device for a vehicle lighting system according to claim 1, characterized by The BUCK voltage reduction circuit includes first, second, third and fourth N-type MOS transistors in parallel.

8. The power supply conversion device for a vehicle lighting system according to claim 4, characterized by The output end of the input filter circuit is connected with the drain of the first N-type MOS, the drain of the second N-type MOS, the drain of the third N-type MOS and the drain of the fourth N-type MOS respectively, the emitter of the NPN triode is connected with the gate of the first N-type MOS, the gate of the second N-type MOS, the gate of the third N-type MOS and the gate of the fourth N-type MOS respectively, and the source of the first N-type MOS, the source of the second N-type MOS, the source of the third N-type MOS and the source of the fourth N-type MOS are connected with the input end of the rectifier filter circuit and the 6th pin of the half-bridge driver respectively.

9. The power supply conversion device for a vehicle lighting system according to claim 1, characterized by The starting circuit comprises a voltage stabilizer, a first diode, a fourth filter capacitor, a third capacitor and a fourth capacitor.

10. The power supply conversion device for a vehicle lighting system according to claim 9, characterized by The 1st pin of the voltage stabilizer is connected with the output end of the BUCK voltage reduction circuit, the 2nd pin is grounded, the 3rd pin is connected with the anode of the first diode, and the cathode of the first diode is connected with the fourth filter capacitor, the third capacitor, the fourth capacitor and the PWM driving circuit respectively.

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