Power supply control circuit and power supply management system for low-power-consumption camera of special vehicle

Abstract

The utility model provides a special vehicle low-power-consumption camera power supply control circuit and a power supply management system. The special vehicle low-power-consumption camera power supply control circuit comprises a power supply control module, an overvoltage protection module and a camera shooting output module. The power supply control module comprises a power supply control chip, an energy storage inductor, a feedback resistor and a power change-over switch unit, the power mode is dynamically adjusted through the power switching end of the vehicle-mounted microcontroller, the output voltage is monitored in real time in combination with the feedback resistor, intelligent switching of different power operation modes is achieved, and the power consumption of the system is effectively reduced. The overvoltage protection module directly samples the output voltage of the power supply control module, and when an overvoltage fault is detected, the power supply enable signal end of the vehicle-mounted microcontroller is forcibly grounded through a hardware circuit, the power supply control chip is triggered to turn off the output, and a dual protection mechanism is formed. According to the circuit, the stable work of the vehicle-mounted camera is ensured, and the improvement of low power consumption and high reliability is realized at the same time.

Description

Technical Field

[0001] This disclosure relates to the technical field of power management for special vehicles, and in particular to a power control circuit and power management system for a low-power camera in special vehicles. Background Technology

[0002] In the field of special vehicles, with the continuous improvement of vehicle intelligence and automation, the application of high-power, high-definition cameras is becoming increasingly widespread. These cameras are not only used for conventional vehicle monitoring, but also widely applied in critical tasks such as autonomous driving, obstacle detection, and environmental perception. However, special vehicles typically need to power multiple high-power cameras simultaneously, which places higher demands on the power control circuitry.

[0003] Existing power systems for special vehicles face significant challenges when multiple high-power cameras operate simultaneously. The concurrent operation of these cameras drastically increases overall system power consumption, requiring the power circuit to output hundreds of watts or even higher. This necessitates a high-power output capability to ensure a stable power supply for each camera, enabling them to function properly and provide clear, accurate images to the vehicle. Therefore, to extend the driving range of special vehicles while reducing energy consumption, the power circuit must also be designed for low power consumption—that is, minimizing its own energy loss while maintaining high power output.

[0004] In practical applications, the working environment of special vehicles is complex and variable. When the power circuit is over-voltaged, it will cause serious damage to electrical equipment such as cameras. Excessive voltage will break down the electronic components inside the camera, causing it to lose its normal function, or even cause safety accidents such as short circuits and fires, which will seriously affect the normal operation and mission execution of special vehicles. Utility Model Content

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a low-power power control circuit and power management system for low-power cameras in special vehicles that can simultaneously ensure power supply to multiple cameras and has overvoltage protection.

[0006] The purpose of this disclosure is achieved through the following technical solution:

[0007] A power control circuit for a low-power camera in a special vehicle includes a power control module, an overvoltage protection module, and a camera output module. The power control module includes a power supply control chip, an energy storage inductor, a feedback resistor, and a power switching unit. The input terminal of the power switching unit is connected to an external power supply terminal, and the control terminal of the power switching unit is connected to the power switching terminal of an on-board microcontroller. The output terminal of the power switching unit is connected to a first terminal of the energy storage inductor, and the second terminal of the energy storage inductor is connected to the power supply terminal of the camera output module. One end of the feedback resistor is connected to the feedback input terminal of the power supply control chip, and the other end of the feedback resistor is connected to the second terminal of the energy storage inductor. The enable input terminal of the power supply control chip is connected to the power enable signal terminal of the on-board microcontroller.

[0008] The overvoltage protection module is used to receive the voltage signal output by the power control module and ground the power enable signal terminal of the vehicle microcontroller when an overvoltage fault occurs in the circuit; the camera output module is used to receive the voltage signal output by the power control module to control the vehicle camera to work.

[0009] In one embodiment, the power switching unit includes a high-power output switch and a low-power output switch. The first terminal of the high-power output switch is connected to an external power supply terminal. The second terminal of the high-power output switch is connected to the first terminal of the energy storage inductor and the first terminal of the low-power output switch. The control terminal of the high-power output switch is connected to the high-load signal output terminal of the power supply control chip. The control terminal of the low-power output switch is connected to the low-load signal output terminal of the power supply control chip. The second terminal of the low-power output switch is grounded.

[0010] In one embodiment, the power control module further includes a chip enable switch, the first end of which is connected to an external power supply terminal, the control terminal of which is connected to the power enable signal terminal of the vehicle microcontroller, and the second end of which is connected to the enable input terminal of the power supply control chip.

[0011] In one embodiment, the overvoltage protection module includes a Zener diode and an overvoltage blocking switch unit. The negative terminal of the Zener diode is connected to the second terminal of the energy storage inductor, the positive terminal of the Zener diode is connected to the control terminal of the overvoltage blocking switch unit, the first terminal of the overvoltage blocking switch unit is connected to the power enable signal terminal of the vehicle microcontroller, and the second terminal of the overvoltage blocking switch unit is grounded.

[0012] In one embodiment, the overvoltage blocking switch unit includes a current-limiting resistor, a first electronic switch, and a second electronic switch. The control terminal of the first electronic switch is connected to the positive terminal of the Zener diode. The first end of the first electronic switch is connected to the control terminal of the second electronic switch. The second end of the first electronic switch is grounded. The first end of the second electronic switch is connected to the power enable signal terminal of the vehicle microcontroller. The second end of the second electronic switch is grounded. The current-limiting resistor is connected in series between the control terminal of the second electronic switch and the external power supply terminal.

[0013] In one embodiment, the power control module further includes a backflow prevention unit, which includes an isolation diode, a voltage divider resistor, a third electronic switch, and a fourth electronic switch. The first terminal of the third electronic switch and the first terminal of the voltage divider resistor are both connected to the second terminal of the energy storage inductor. The second terminal of the voltage divider resistor is connected to the control terminal of the third electronic switch. The second terminal of the third electronic switch is connected to the positive terminal of the isolation diode. The negative terminal of the isolation diode is connected to the power supply terminal of the camera output module. The first terminal of the fourth electronic switch is connected to the control terminal of the third electronic switch. The control terminal of the fourth electronic switch is used to connect to the camera enable signal terminal of the vehicle microcontroller. The second terminal of the fourth electronic switch is grounded.

[0014] In one embodiment, the backflow prevention protection unit further includes an overcurrent protection element, the first end of which is connected to the negative terminal of the isolation diode, and the second end of which is connected to the power supply terminal of the camera output module.

[0015] In one embodiment, the power supply control chip is model SCT82A30DHK.

[0016] In one embodiment, the camera output module includes a camera main control chip and a camera output circuit, wherein the drive signal output terminal of the camera main control chip is connected to the drive signal receiving terminal that controls the camera output circuit.

[0017] This application also provides a power management system, including the power control circuit for a low-power camera in a special vehicle as described in any embodiment.

[0018] Compared with the prior art, this disclosure has at least the following advantages:

[0019] The aforementioned power control circuit for the low-power camera in special vehicles monitors the output voltage through a feedback resistor and drives the power switching unit to switch to different power operation modes based on voltage changes, thereby effectively reducing circuit power consumption. On the other hand, by monitoring the voltage signal in real time through an overvoltage protection module, the power enable signal terminal of the vehicle microcontroller can be grounded through hardware circuitry in the event of an overvoltage fault, causing the power supply control chip to stop supplying power and thus preventing damage to the equipment from excessive voltage. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A circuit diagram of a power control circuit for a low-power camera in a special vehicle, as shown in one embodiment.

[0022] Figure 2 for Figure 1 The circuit diagram of the backflow prevention protection unit is shown below;

[0023] Figure 3 for Figure 1 The circuit diagram of the overvoltage protection module shown is shown.

[0024] Figure 4 for Figure 1 The circuit diagram of the camera output module is shown. Detailed Implementation

[0025] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0026] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments:

[0029] like Figure 1 As shown, a power control circuit 10 for a low-power camera in a special vehicle according to an embodiment of this disclosure includes a power control module 100, an overvoltage protection module 200, and a camera output module 300. The power control module 100 includes a power supply control chip U1, an energy storage inductor L3, a feedback resistor R3, and a power switching unit. The input terminal of the power switching unit is connected to an external power supply terminal, and the control terminal of the power switching unit is connected to the power switching terminal of the vehicle microcontroller. The output terminal of the power switching unit is connected to the first terminal of the energy storage inductor L3, and the second terminal of the energy storage inductor L3 is connected to the power supply terminal of the camera output module 300. One end of the feedback resistor R3 is connected to the feedback input terminal FB of the power supply control chip U1, and the other end of the feedback resistor R3 is connected to the second terminal of the energy storage inductor L3. The enable input terminal VIN of the power supply control chip U1 is connected to the power enable signal terminal DC_EN of the vehicle microcontroller.

[0030] The overvoltage protection module 200 is used to receive the voltage signal output by the power control module 100 and ground the DC_EN power enable signal terminal of the vehicle microcontroller when an overvoltage fault occurs in the circuit; the camera output module 300 is used to receive the voltage signal output by the power control module 100 to control the vehicle camera to work.

[0031] In this embodiment, when the special vehicle starts and the on-board battery begins to supply power, the power enable signal terminal DC_EN of the on-board microcontroller outputs a level signal to the enable input terminal VIN of the power supply control chip U1, causing the power supply control chip U1 to enter the working state. At this time, the power supply control chip U1 sends a PWM control signal to the control terminal of the power switching unit through the power switching terminal to turn on the power switching unit. Then, the voltage of the external power supply is transmitted to the first terminal of the energy storage inductor L3, and a voltage signal is output through its second terminal to power the camera output module 300. After receiving the voltage signal, the camera output module 300 drives the on-board camera to start working normally, performing image acquisition and transmission operations.

[0032] Meanwhile, feedback resistor R3 is connected between the feedback input terminal FB of power supply control chip U1 and the second terminal of energy storage inductor L3, forming a feedback loop. Feedback resistor R3 monitors the output voltage of the second terminal of energy storage inductor L3 in real time and transmits this voltage signal as a feedback voltage signal to power supply control chip U1. Specifically, when the driver completely turns off the vehicle camera, feedback resistor R3 sends a feedback voltage signal to power supply control chip U1 based on the change in output voltage at the second terminal of energy storage inductor L3. This causes power supply control chip U1 to drive the power switching unit to switch to low-power operation mode, thereby reducing the power consumption of the special vehicle low-power camera power control circuit. When the driver needs to view multiple vehicle camera feeds, feedback resistor R3 again drives the power switching unit to switch to high-power operation mode based on the change in output voltage at the second terminal of energy storage inductor L3, thus enabling the special vehicle low-power camera power control circuit 10 to flexibly adjust its output power.

[0033] Furthermore, the overvoltage protection module 200 is internally equipped with an overvoltage detection circuit, which monitors the voltage signal output by the power control module 100 in real time and compares it with a preset overvoltage threshold. In the event of an overvoltage fault, the overvoltage protection module 200 grounds the DC_EN power enable signal terminal of the vehicle microcontroller via hardware circuitry. This causes the VIN enable input terminal of the power supply control chip U1 to receive a low-level signal, stopping the power supply control chip U1 from operating and turning off the power switching unit, thereby stopping power supply to the camera output module 300. This effectively prevents excessive voltage from damaging the camera output module 300 and the vehicle camera.

[0034] The aforementioned power control circuit 10 for the special vehicle low-power camera monitors the output voltage through feedback resistor R3 and drives the power switching unit to switch to different power operation modes according to voltage changes, thereby effectively reducing circuit power consumption. On the other hand, the overvoltage protection module 200 monitors the voltage signal in real time, and can ground the DC_EN power enable signal terminal of the vehicle microcontroller through hardware circuitry when an overvoltage fault occurs, so that the power supply control chip U1 stops supplying power, thereby preventing damage to the equipment caused by excessive voltage.

[0035] In one embodiment, please refer to Figure 1The power switching unit includes a high-power output switch Q2 and a low-power output switch Q3. The first terminal of the high-power output switch Q2 is connected to the external power supply terminal, and the second terminal of the high-power output switch Q2 is connected to the first terminal of the energy storage inductor L3 and the first terminal of the low-power output switch Q3, respectively. The control terminal of the high-power output switch Q2 is connected to the high-load signal output terminal HO of the power supply control chip U1, and the control terminal of the low-power output switch Q3 is connected to the low-load signal output terminal LO of the power supply control chip U1. The second terminal of the low-power output switch Q3 is grounded. In this embodiment, when the special vehicle driver needs to observe the images from multiple vehicle-mounted cameras, the load demand of the camera output module 300 increases. The feedback resistor R3 detects a drop in the output voltage at the second terminal of the energy storage inductor L3 and transmits a feedback voltage signal to the power supply control chip U1 based on this voltage change. After receiving the feedback signal, the power supply control chip U1 determines that high power output is required, and then outputs a high-level control signal through the high-load signal output terminal HO, while simultaneously outputting a low-level control signal to the low-load signal output terminal LO. When the control terminal of the high-power output switch Q2 receives a high-level signal, it turns on. Since the first terminal of the high-power output switch Q2 is connected to the external power supply terminal, the voltage of the external power supply is transmitted to the first terminal of the energy storage inductor L3 through the high-power output switch Q2.

[0036] Simultaneously, the control terminal of the low-power output switch Q3 turns off upon receiving a low-level signal, preventing a short circuit caused by current flowing through Q3. At this time, the voltage from the external power supply provides a larger current and power to the camera output module 300 through the high-power output switch Q2 and the energy storage inductor L3, enabling the camera output module 300 to drive multiple vehicle cameras to operate normally, thus meeting the driver's need to view multiple images.

[0037] When the driver completely shuts down the vehicle camera, the load demand of the camera output module 300 is relatively small. The feedback resistor R3 detects an increase in the output voltage at the second terminal of the energy storage inductor L3 and transmits a feedback voltage signal to the power supply control chip U1 based on this voltage change. After receiving the feedback signal, the power supply control chip U1 determines that low power output is required and outputs a low-level control signal to the high load signal output terminal HO, while simultaneously outputting a high-level control signal to the low load signal output terminal LO. Upon receiving the low-level signal, the control terminal of the high-power output switch Q2 turns off, cutting off the power supply path from the external power supply to the energy storage inductor L3 through the high-power output switch Q2. Meanwhile, the control terminal of the low-power output switch Q3 turns on upon receiving the high-level signal, but since its second terminal is grounded, the camera output module 300 maintains a basic standby state with a small current mainly through the energy storage function of the energy storage inductor L3, thereby effectively reducing the power consumption of the special vehicle low-power camera power control circuit 10.

[0038] In another embodiment, both the high-power output switch Q2 and the low-power output switch Q3 are N-channel MOSFETs. The first terminal of both the high-power output switch Q2 and the low-power output switch Q3 are the drains of the N-channel MOSFETs, the second terminal of both the high-power output switch Q2 and the low-power output switch Q3 are the sources of the N-channel MOSFETs, and the control terminal of both the high-power output switch Q2 and the low-power output switch Q3 are the gates of the N-channel MOSFETs.

[0039] In one embodiment, please refer to Figure 1 The power control module 100 also includes a chip enable switch Q1. The first terminal of the chip enable switch Q1 is connected to an external power supply terminal. The control terminal of the chip enable switch Q1 is connected to the power enable signal terminal DC_EN of the vehicle microcontroller. The second terminal of the chip enable switch Q1 is connected to the enable input terminal VIN of the power supply control chip U1. In this embodiment, when the special vehicle starts and the on-board battery begins supplying power, the power enable signal terminal DC_EN of the vehicle microcontroller outputs a high-level signal to the control terminal of the chip enable switch Q1. Upon receiving the high-level signal, the chip enable switch Q1 turns on. Since the first terminal of the chip enable switch Q1 is connected to the external power supply terminal, the voltage of the external power supply is transmitted to the enable input terminal VIN of the power supply control chip U1 through the chip enable switch Q1. After the enable input terminal VIN of the power supply control chip U1 receives the high-level signal, the power supply control chip U1 enters the working state.

[0040] When an overvoltage fault occurs in the circuit, the overvoltage protection module 200 grounds the power enable signal terminal DC_EN of the vehicle microcontroller, causing it to output a low-level signal. Upon receiving the low-level signal, the control terminal of the chip enable switch Q1 turns off, cutting off the power supply path from the external power source to the enable input terminal VIN of the power supply control chip U1. After receiving the low-level signal at its enable input terminal VIN, the power supply control chip U1 stops operating, effectively preventing damage to the camera output module 300 and the vehicle camera caused by excessive voltage. When the special vehicle is in a long-term parking or standby state, the vehicle microcontroller can control the power enable signal terminal DC_EN to output a low-level signal according to the actual situation, turning off the chip enable switch Q1. At this time, the power supply control chip U1 stops operating, and the entire power control circuit is in a low-power state, thereby reducing the circuit's energy consumption.

[0041] In another embodiment, the chip enable switch Q1 is an N-channel MOS transistor, the first terminal of the chip enable switch Q1 is the drain of the N-channel MOS transistor, the second terminal of the chip enable switch Q1 is the source of the N-channel MOS transistor, and the control terminal of the chip enable switch Q1 is the gate of the N-channel MOS transistor.

[0042] In one embodiment, please refer to Figure 3 The overvoltage protection module 200 includes a Zener diode ZD2 and an overvoltage blocking switch unit. The cathode of the Zener diode ZD2 is connected to the second terminal of the energy storage inductor L3, and the anode of the Zener diode ZD2 is connected to the control terminal of the overvoltage blocking switch unit. The first terminal of the overvoltage blocking switch unit is connected to the power enable signal terminal DC_EN of the vehicle microcontroller, and the second terminal of the overvoltage blocking switch unit is grounded. In this embodiment, when an overvoltage fault occurs in the voltage signal output by the power control module 100, the voltage at the second terminal of the energy storage inductor L3 increases. When this voltage exceeds the Zener diode ZD2's regulation voltage, the Zener diode ZD2 breaks down and conducts. After the Zener diode ZD2 conducts, it raises the voltage at the control terminal of the overvoltage blocking switch unit to its conduction threshold, causing the overvoltage blocking switch unit to conduct. After the overvoltage blocking switch unit conducts, it grounds the power enable signal terminal DC_EN of the vehicle microcontroller. At this time, the power enable signal terminal DC_EN outputs a low-level signal. This low-level signal is transmitted to the control terminal of the chip enable switch Q1, and the chip enable switch Q1 is turned off. Since the chip enable switch Q1 is turned off, the power supply path from the external power supply to the enable input terminal VIN of the power supply control chip U1 is cut off. After the enable input terminal VIN of the power supply control chip U1 receives the low-level signal, the power supply control chip U1 stops working.

[0043] In one embodiment, please refer to Figure 3The overvoltage blocking switch unit includes a current-limiting resistor R4, a first electronic switch Q4, and a second electronic switch Q5. The control terminal of the first electronic switch Q4 is connected to the positive terminal of the Zener diode ZD2. The first terminal of the first electronic switch Q4 is connected to the control terminal of the second electronic switch Q5, and the second terminal of the first electronic switch Q4 is grounded. The first terminal of the second electronic switch Q5 is connected to the power enable signal terminal DC_EN of the vehicle microcontroller, and the second terminal of the second electronic switch Q5 is grounded. The current-limiting resistor R4 is connected in series between the control terminal of the second electronic switch Q5 and the external power supply terminal. In this embodiment, when the voltage signal output by the power control module 100 is normal, the voltage signal does not exceed the Zener voltage value of the Zener diode ZD2, so the Zener diode ZD2 is in the off state. At this time, there is no conduction signal at the control terminal of the first electronic switch Q4, and the first electronic switch Q4 remains in the off state. Because the first electronic switch Q4 is off, the connection between its first terminal and the control terminal of the second electronic switch Q5 is in a high-impedance state. The control terminal of the second electronic switch Q5 is connected to the external power supply terminal through the current-limiting resistor R4, but due to the limitation of the current-limiting resistor R4 and the control logic of the second electronic switch Q5 itself, the second electronic switch Q5 is also in the off state. The power enable signal terminal DC_EN of the vehicle microcontroller remains disconnected from ground, the power enable signal is output normally, the power supply control chip U1 can work normally, and the entire power control circuit is in a normal power supply state.

[0044] Furthermore, when an overvoltage fault occurs in the voltage signal output by the power control module 100, the voltage at the second terminal of the energy storage inductor L3 increases and exceeds the voltage regulation value of the Zener diode ZD2, causing the Zener diode ZD2 to break down and conduct. After the Zener diode ZD2 conducts, the voltage at the control terminal of the first electronic switch Q4 increases to its conduction threshold voltage, thus turning on the first electronic switch Q4. After the first electronic switch Q4 conducts, the connection between its first terminal and the control terminal of the second electronic switch Q5 becomes low-impedance, pulling down the voltage at the control terminal of the second electronic switch Q5. After receiving a low-level signal, the control terminal of the second electronic switch Q5 conducts, grounding the power enable signal terminal DC_EN of the vehicle microcontroller. After the power enable signal terminal DC_EN is grounded, a low-level signal is output, which is transmitted to the control terminal of the chip enable switch Q1, turning off the chip enable switch Q1. Because the enable switch Q1 of the chip is turned off, the power supply path from the external power supply to the enable input terminal VIN of the power supply control chip U1 is cut off. After the enable input terminal VIN of the power supply control chip U1 receives a low-level signal, the power supply control chip U1 stops working, thereby cutting off the power supply path from the external power supply to the energy storage inductor L3 and the camera output module 300, thus effectively avoiding damage to the camera output module 300 and the vehicle camera caused by excessive voltage.

[0045] In another embodiment, the first electronic switch Q4 is an NPN transistor, and the second electronic switch Q5 is a PNP transistor. The first terminal of the first electronic switch Q4 is the collector of the NPN transistor, the second terminal of the first electronic switch Q4 is the emitter of the NPN transistor, and the control terminal of the first electronic switch Q4 is the base of the NPN transistor. The first terminal of the second electronic switch Q5 is the emitter of the PNP transistor, the second terminal of the second electronic switch Q5 is the collector of the PNP transistor, and the control terminal of the second electronic switch Q5 is the base of the PNP transistor.

[0046] In one embodiment, please refer to Figure 2 The power control module 100 also includes a backflow prevention unit 110, which includes an isolation diode D2, a voltage divider resistor R5, a third electronic switch Q6, and a fourth electronic switch Q7. The first terminal of the third electronic switch Q6 and the first terminal of the voltage divider resistor R5 are both connected to the second terminal of the energy storage inductor L3. The second terminal of the voltage divider resistor R5 is connected to the control terminal of the third electronic switch Q6. The second terminal of the third electronic switch Q6 is connected to the anode of the isolation diode D2, and the cathode of the isolation diode D2 is connected to the power supply terminal of the camera output module 300. The first terminal of the fourth electronic switch Q7 is connected to the control terminal of the third electronic switch Q6. The control terminal of the fourth electronic switch Q7 is used to connect to the camera enable signal terminal CAM_EN of the vehicle microcontroller, and the second terminal of the fourth electronic switch Q7 is grounded. In this embodiment, when the special vehicle is normally powered and the camera enable signal terminal CAM_EN of the vehicle microcontroller outputs a high-level signal, the control terminal of the fourth electronic switch Q7 receives the high-level signal, thus turning it on. After the fourth electronic switch Q7 is turned on, it pulls the control terminal voltage of the third electronic switch Q6 to a low level, thus turning on the third electronic switch Q6. Once Q6 is on, the voltage output from the energy storage inductor L3 can be transmitted to the power supply terminal of the camera output module 300 through the third electronic switch Q6 and the isolation diode D2, providing the camera output module 300 with normal operating voltage and enabling the vehicle camera to function properly. At this time, the isolation diode D2 is in a forward-biased state, allowing current to flow from the energy storage inductor L3 to the camera output module 300.

[0047] When the camera enable signal terminal CAM_EN of the vehicle microcontroller outputs a low-level signal, the control terminal of the fourth electronic switch Q7 receives a low-level signal, turning it off. At this time, the control terminal of the third electronic switch Q6 is no longer pulled low to ground potential. The voltage divider resistor R5 divides the voltage output of the energy storage inductor L3. Since the fourth electronic switch Q7 is off, the voltage at the control terminal of the third electronic switch Q6 no longer meets the conduction condition, and the third electronic switch Q6 is turned off. After the third electronic switch Q6 is turned off, the power supply path between the energy storage inductor L3 and the camera output module 300 is cut off, preventing the power supply from continuing to supply power to the camera output module 300 when the camera function is not needed, thereby reducing the power consumption of the circuit. At the same time, due to the unidirectional conduction characteristic of the isolation diode D2, the reverse voltage cannot turn on the isolation diode D2, thus preventing the reverse voltage that may be generated inside the camera output module 300 from flowing back into the power control module.

[0048] In another embodiment, the third electronic switch Q6 is a P-channel MOSFET, the fourth electronic switch Q7 is an NPN transistor, the first terminal of the third electronic switch Q6 is the source of the P-channel MOSFET, the second terminal of the third electronic switch Q6 is the source of the P-channel MOSFET, the control terminal of the third electronic switch Q6 is the gate of the P-channel MOSFET, the first terminal of the fourth electronic switch Q7 is the collector of the NPN transistor, the second terminal of the fourth electronic switch Q7 is the emitter of the NPN transistor, and the control terminal of the fourth electronic switch Q7 is the base of the NPN transistor.

[0049] In one embodiment, please refer to Figure 2 The backflow prevention unit 110 also includes an overcurrent protection element FUSE. The first terminal of the overcurrent protection element FUSE is connected to the negative terminal of the isolation diode D2, and the second terminal of the overcurrent protection element FUSE is connected to the power supply terminal of the camera output module 300. In this embodiment, when an abnormal situation occurs in the circuit, the current suddenly increases sharply, causing the current through the overcurrent protection element FUSE to exceed its rated value. At this time, the overcurrent protection element FUSE will respond quickly. Because the overcurrent protection element FUSE typically uses special materials or structural designs, when the current exceeds a set threshold, its internal fuse will melt due to overheating, thereby cutting off the power supply path from the energy storage inductor L3 through the isolation diode D2 to the camera output module 300, preventing excessive current from continuing to flow to the camera output module 300, and thus avoiding damage to the camera output module 300 and its connected vehicle camera and other equipment due to overcurrent.

[0050] In one embodiment, the power supply control chip U1 is an SCT82A30DHK. In this embodiment, the input voltage range of the SCT82A30DHK is 4.5V to 36V to adapt to the on-board batteries of special vehicles, thereby meeting the high power requirements of multiple cameras. When the on-board microcontroller outputs a high level via DC_EN, after the chip enable switch Q1 is turned on, the VIN pin of the SCT82A30DHK is powered. The chip drives the high-power switch Q2 and the low-power switch Q3 through the HO and LO pins respectively, adjusting the duty cycle according to the feedback voltage to stabilize the output voltage. Specifically, when multiple cameras are working simultaneously, the feedback resistor R3 detects a drop in output voltage. The FB pin of the SCT82A30DHK receives the feedback signal, and the power supply control chip U1 compares the feedback voltage with the reference voltage through its internal error amplifier, increasing the PWM duty cycle to improve the output voltage. When the cameras are turned off, the feedback voltage rises, and the power supply control chip U1 detects a light-load state. The SCT82A30DHK automatically switches to pulse frequency modulation mode to reduce the switching frequency and minimize power loss.

[0051] In one embodiment, please refer to Figure 4 The camera output module 300 includes a camera main control chip U2 and a camera output circuit. The drive signal output terminal of the camera main control chip U2 is connected to the drive signal receiving terminal of the camera output circuit. In this embodiment, the camera main control chip U2 is model XS9950. When the driver needs to observe the images from multiple vehicle cameras, the feedback resistor R3 detects a drop in the output voltage at the second terminal of the energy storage inductor L3. The power supply control chip U1 drives the power switching unit to switch to high-power operation mode, providing a larger current and power to the camera output module 300. At this time, the XS9950 chip can reasonably allocate drive signals according to the access status of multiple cameras, ensuring that each camera can work normally, and integrating and processing the collected image data to meet the needs of multiple cameras working simultaneously. This allows the driver to observe images from different angles simultaneously, improving driving safety and control over the vehicle's surrounding environment. When the driver only needs to observe the image from a single camera or the load demand of the camera output module 300 is small, the feedback resistor R3 detects an increase in the output voltage at the second terminal of the energy storage inductor L3. The power supply control chip U1 then drives the power switching unit to switch to a low-power operating mode. The camera main control chip U2 adjusts the drive signal accordingly, reducing the camera's frame rate or resolution, decreasing the amount of image data processed, and thus reducing the overall power consumption of the camera output module 300.

[0052] This application also provides a power management system, including a power control circuit 10 for a low-power camera in a special vehicle according to any embodiment. In this embodiment, when the special vehicle starts and the on-board battery begins to supply power, the power enable signal terminal DC_EN of the on-board microcontroller outputs a level signal to the enable input terminal VIN of the power supply control chip U1, causing the power supply control chip U1 to enter the working state. At this time, the power supply control chip U1 sends a PWM control signal to the control terminal of the power switching unit through the power switching terminal to turn on the power switching unit. Then, the voltage of the external power supply is transmitted to the first terminal of the energy storage inductor L3, and the voltage signal is output through its second terminal to power the camera output module 300. After receiving the voltage signal, the camera output module 300 drives the on-board camera to start normal operation, performing image acquisition and transmission operations. At the same time, the feedback resistor R3 is connected between the feedback input terminal FB of the power supply control chip U1 and the second terminal of the energy storage inductor L3 to form a feedback loop. The feedback resistor R3 monitors the output voltage of the second terminal of the energy storage inductor L3 in real time and transmits the voltage signal as a feedback voltage signal to the power supply control chip U1. Specifically, when the driver completely shuts down the vehicle camera, the feedback resistor R3 sends a voltage signal to the power supply control chip U1 based on the output voltage change at the second terminal of the energy storage inductor L3. This causes the power supply control chip U1 to switch the power switching unit to a low-power operating mode, thereby reducing the power consumption of the special vehicle low-power camera power control circuit. When the driver needs to view multiple vehicle camera feeds, the feedback resistor R3 again sends the power switching unit to a high-power operating mode based on the output voltage change at the second terminal of the energy storage inductor L3. This allows the special vehicle low-power camera power control circuit 10 to flexibly adjust its output power. Furthermore, the overvoltage protection module 200 has an internal overvoltage detection circuit that monitors the voltage signal output by the power control module 100 in real time and compares it with a preset overvoltage threshold. When an overvoltage fault occurs, the overvoltage protection module 200 grounds the power enable signal terminal DC_EN of the vehicle microcontroller through hardware circuitry, so that the enable input terminal VIN of the power supply control chip U1 receives a low-level signal, the power supply control chip U1 stops working, the power switching unit is turned off, thereby stopping the power supply to the camera output module 300, thus effectively preventing excessive voltage from damaging the camera output module 300 and the vehicle camera.

[0053] Compared with the prior art, this disclosure has at least the following advantages:

[0054] The aforementioned power control circuit 10 for the special vehicle low-power camera monitors the output voltage through feedback resistor R3 and drives the power switching unit to switch to different power operation modes according to voltage changes, thereby effectively reducing circuit power consumption. On the other hand, the overvoltage protection module 200 monitors the voltage signal in real time, and can ground the DC_EN power enable signal terminal of the vehicle microcontroller through hardware circuitry when an overvoltage fault occurs, so that the power supply control chip U1 stops supplying power, thereby preventing damage to the equipment caused by excessive voltage.

[0055] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A special vehicle low-power consumption camera power supply control circuit, characterized in that, Includes a power control module, an overvoltage protection module, and a camera output module. The power control module includes a power control chip, an energy storage inductor, a feedback resistor, and a power switching unit. The input terminal of the power switching unit is connected to an external power supply terminal, and the control terminal of the power switching unit is connected to the power switching terminal of the vehicle microcontroller. The output terminal of the power switching unit is connected to the first terminal of the energy storage inductor, and the second terminal of the energy storage inductor is connected to the power supply terminal of the camera output module. One end of the feedback resistor is connected to the feedback input terminal of the power control chip, and the other end of the feedback resistor is connected to the second terminal of the energy storage inductor. The enable input terminal of the power control chip is connected to the power enable signal terminal of the vehicle microcontroller. The overvoltage protection module is used to receive the voltage signal output by the power control module and ground the power enable signal terminal of the vehicle microcontroller when an overvoltage fault occurs in the circuit. The camera output module is used to receive the voltage signal output by the power control module in order to control the vehicle camera to work.

2. The special vehicle low power consumption camera power control circuit of claim 1, wherein, The power switching unit includes a high-power output switch and a low-power output switch. The first terminal of the high-power output switch is connected to an external power supply terminal. The second terminal of the high-power output switch is connected to the first terminal of the energy storage inductor and the first terminal of the low-power output switch. The control terminal of the high-power output switch is connected to the high-load signal output terminal of the power supply control chip. The control terminal of the low-power output switch is connected to the low-load signal output terminal of the power supply control chip. The second terminal of the low-power output switch is grounded.

3. The power control circuit for a low-power camera on a special vehicle according to claim 1, characterized in that, The power control module also includes a chip enable switch. The first end of the chip enable switch is used to connect to an external power supply terminal, the control terminal of the chip enable switch is connected to the power enable signal terminal of the vehicle microcontroller, and the second end of the chip enable switch is connected to the enable input terminal of the power supply control chip.

4. The power control circuit for a low-power camera on a special vehicle according to claim 1, characterized in that, The overvoltage protection module includes a Zener diode and an overvoltage blocking switch unit. The negative terminal of the Zener diode is connected to the second terminal of the energy storage inductor, the positive terminal of the Zener diode is connected to the control terminal of the overvoltage blocking switch unit, the first terminal of the overvoltage blocking switch unit is connected to the power enable signal terminal of the vehicle microcontroller, and the second terminal of the overvoltage blocking switch unit is grounded.

5. The power control circuit for a low-power camera on a special vehicle according to claim 4, characterized in that, The overvoltage blocking switch unit includes a current-limiting resistor, a first electronic switch, and a second electronic switch. The control terminal of the first electronic switch is connected to the positive terminal of the Zener diode. The first end of the first electronic switch is connected to the control terminal of the second electronic switch. The second end of the first electronic switch is grounded. The first end of the second electronic switch is connected to the power enable signal terminal of the vehicle microcontroller. The second end of the second electronic switch is grounded. The current-limiting resistor is connected in series between the control terminal of the second electronic switch and the external power supply terminal.

6. The power control circuit for a low-power camera on a special vehicle according to claim 1, characterized in that, The power control module also includes a backflow prevention unit, which includes an isolation diode, a voltage divider resistor, a third electronic switch, and a fourth electronic switch. The first terminal of the third electronic switch and the first terminal of the voltage divider resistor are both connected to the second terminal of the energy storage inductor. The second terminal of the voltage divider resistor is connected to the control terminal of the third electronic switch. The second terminal of the third electronic switch is connected to the positive terminal of the isolation diode. The negative terminal of the isolation diode is connected to the power supply terminal of the camera output module. The first terminal of the fourth electronic switch is connected to the control terminal of the third electronic switch. The control terminal of the fourth electronic switch is used to connect to the camera enable signal terminal of the vehicle microcontroller. The second terminal of the fourth electronic switch is grounded.

7. The power control circuit for a low-power camera on a special vehicle according to claim 6, characterized in that, The backflow prevention protection unit also includes an overcurrent protection element. The first end of the overcurrent protection element is connected to the negative terminal of the isolation diode, and the second end of the overcurrent protection element is connected to the power supply terminal of the camera output module.

8. The power control circuit for a low-power camera on a special vehicle according to claim 1, characterized in that, The power supply control chip is model SCT82A30DHK.

9. The power control circuit for a low-power camera on a special vehicle according to claim 1, characterized in that, The camera output module includes a camera main control chip and a camera output circuit. The drive signal output terminal of the camera main control chip is connected to the drive signal receiving terminal that controls the camera output circuit.

10. A power management system, characterized in that, Includes the power control circuit for a low-power camera for special vehicles as described in any one of claims 1 to 9.

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