Redundant power supply switching circuit structure of vehicle-mounted TBOX

Abstract

The utility model provides a kind of redundancy power supply switching circuit structure of vehicle-mounted TBOX, including mains input interface circuit, mains step-down conversion circuit, dynamic voltage monitoring and switching circuit, backup battery input circuit, battery boost circuit and vehicle-mounted TBOX system, the output end of mains input interface circuit is electrically connected with the input end of mains step-down conversion circuit and the input end of dynamic voltage monitoring and switching circuit respectively, the output end of mains step-down conversion circuit is electrically connected with vehicle-mounted TBOX system, the output end of dynamic voltage monitoring and switching circuit is electrically connected with the input end of backup battery input circuit, the output end of backup battery input circuit is electrically connected with the input end of battery boost circuit, the input end of battery boost circuit is electrically connected with vehicle-mounted TBOX system.The utility model triggers contactless switching by dynamic voltage monitoring, semiconductor switch, multistage protection and redundancy framework, solves the problem of low efficiency, delay and other problems in traditional vehicle-mounted TBOX power supply switching.

Description

Technical Field

[0001] This utility model relates to the field of power circuit technology for vehicle-mounted equipment, and in particular to the redundant power switching circuit structure of a vehicle-mounted TBOX. Background Technology

[0002] As a core component of the Internet of Vehicles (IoV), the vehicle-mounted TBOX needs to maintain stable power supply under complex vehicle power environments (such as cold starts and voltage drops). Existing solutions generally use a combination of a main power supply (24V battery) and a backup battery (such as a NiMH battery), providing multi-level voltages to the MCU, communication modules, etc., through power conversion modules (DC-DC, LDO). Existing vehicle-mounted TBOX power switching technologies have some problems and shortcomings, including the risk of power interruption due to switching response time delay, electromagnetic interference affecting switching stability, insufficient voltage threshold monitoring accuracy, and the lack of redundant power supply parallel power supply design. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: The redundant power switching circuit structure of the vehicle-mounted TBOX includes a main power input interface circuit, a main power step-down conversion circuit, a dynamic voltage monitoring and switching circuit, a backup battery input circuit, a battery boost circuit, and a vehicle-mounted TBOX system. The output terminal of the main power input interface circuit is electrically connected to the input terminal of the main power step-down conversion circuit and the input terminal of the dynamic voltage monitoring and switching circuit, respectively. The output terminal of the main power step-down conversion circuit is electrically connected to the vehicle-mounted TBOX system. The output terminal of the dynamic voltage monitoring and switching circuit is electrically connected to the input terminal of the battery input circuit. The output terminal of the battery input circuit is electrically connected to the input terminal of the battery boost circuit. The input terminal of the battery boost circuit is electrically connected to the vehicle-mounted TBOX system.

[0005] The main power input interface circuit includes interface BATT, interface VBAT, ground, power inductor L3101, filter capacitors C3101, C3102, and C3103, and diodes D3101, D3102, D3103, and D3104. Interfaces BATT and VBAT are current input ports, and ground is the negative terminal of the circuit. Power inductor L3101 is connected in series between interface BATT and interface VBAT. Filter capacitors C3101, C3102, and C3103 are connected in parallel between interface VBAT and ground. In this circuit, diode D3101 is a reverse-connection diode used to prevent reverse current flow. It is connected in series between interface BATT and interface VBAT, and the cathode of diode D3101 is electrically connected to filter capacitors C3102 and C3103 respectively. Diode D3102 is a TVS transient voltage suppressor used to protect the circuit. It is connected in parallel between interface BATT and ground. Diodes D3103 and D3104 are rectifier diodes. Diode D3104 is connected in series with D3102, and diodes D3103 are connected in parallel with D3102.

[0006] The main power supply step-down converter circuit includes an interface VBAT, a ground terminal, a DC-DC step-down chip U3101, a filter capacitor, a voltage divider feedback resistor network, an energy storage inductor, an interface 5VDC-CDC, an interface 5VMEM, an interface 3VMEM, an MCU unit, and a freewheeling diode. The interface VBAT is the positive power supply terminal, and the ground terminal is the negative power supply terminal. Pins 1 and 2 of the DC-DC step-down chip are connected to inductor L3103, pin 3 of the DC-DC step-down chip is connected to filter C3112, pin 4 of the DC-DC step-down chip is connected to capacitor C3124, pin 5 of the DC-DC step-down chip is connected to voltage divider resistor R3117, and pins 6, 7, 9, 10, 11, 12, and 15 of the DC-DC step-down chip are connected to the ground terminal. Pins 16 and 17 are grounded respectively. Pins 13 and 14 of the DC-DC step-down chip are electrically connected to the VBAT interface. Energy storage inductors include L3102 and L3103. Energy storage inductor L3102 is connected in series between the VBAT interface and pins 13 and 14 of the DC-DC step-down chip, and energy storage inductor L3103 is connected in series between pins 1 and 2 of the DC-DC step-down chip and the 5VDC-DC interface. Voltage divider resistors include R3105, R3107, R3112, R3116, R3117, R3118, R3119, R3129, R3200, R3134, R3136, R3126, R3138, R3132, and R3128. Filter capacitors include C3105. C3106, C3107, C3108, C3109, C3122, C3112, C3113, C3171, C3124, C3114, C3115, C3116, C3118, C3125; voltage divider resistor R3105 is connected in series between pins 1 and 2 of the DC-DC step-down chip and ground; voltage divider resistor R3112 is connected between pin 14 of the DC-DC step-down chip and ground; voltage divider resistor R3116 is connected in series between the 3V3MEM interface and pin 8 of the DC-DC step-down chip; voltage divider resistor R3117 is connected between the 5VDC-DC interface and pins 1 and 2 of the DC-DC step-down chip; voltage divider resistor R3118 is connected to the pins of the DC-DC step-down chip. Between pin 5 and ground, voltage divider resistor R3119 is connected between the 5V DC-DC interface and voltage divider resistor R3128. Voltage divider resistors R3129 and R3200 are connected in series between pin 7 of the DC-DC step-down chip and ground. Voltage divider resistor R3134 is connected in series between pin 6 of the DC-DC step-down chip and ground. Voltage divider resistor R3136 is connected in series between pin 9 of the DC-DC step-down chip and ground. Voltage divider resistors R3126 and R3138 are connected in series between the 5V DC-DC interface and ground. Voltage divider resistor R3132 is connected between the MCU unit and the gate (G) of freewheeling diode Q3105. Voltage divider resistor R3128 is connected in series between voltage divider resistor R3119 and the drain (D) of freewheeling diode Q3105.Filter capacitor C3105 is connected in series with voltage divider resistor R3105; filter capacitors C3106 and C3109 are connected in parallel with the 5V DC-DC interface; filter capacitors C3107 and C3108 are connected in parallel with energy storage inductor L3102; filter capacitor C3122 is connected in series on pin 11 of the DC-DC step-down chip; filter capacitor C3112 is connected between pin 3 of the DC-DC step-down chip and the input terminal of energy storage inductor L3103; filter capacitor C3113 is connected in parallel with voltage divider resistor R3118; filter capacitor C3171 is connected between pin 5 of the DC-DC step-down chip and ground; filter capacitor C3124 is connected in series on pin 4 of the DC-DC step-down chip; filter capacitors C3114, C3115, and C3116 are connected in parallel between the output terminal of energy storage inductor L3103 and ground; filter capacitor C3... 118 is connected in parallel with the voltage divider resistor R3119. The filter capacitor C3125 is connected between the gate (G) of the freewheeling diode Q3105 and ground. The 5VDC-CDC interface is the power output; the 5VMEM interface is a 5V storage or specific function module power supply interface; and the 3VMEM interface is a 3.3V storage or specific function module power supply interface. The MCU unit is the control unit. The freewheeling diode is a combination switch of a PMOS and an NMOS transistor. The drain (D) and source (S) of the freewheeling diode Q3104 are connected to the 5VDC-CDC and 5VMEM interfaces, respectively. The gate (G) of the freewheeling diode Q3104 is connected to the voltage divider resistor R3128. The drain (D) of the freewheeling diode Q3105 is connected to the voltage divider resistor R3128. The gate (G) of the freewheeling diode Q3105 is connected to the filter capacitor C3125. The source (S) of the freewheeling diode Q3105 is grounded.

[0007] The dynamic voltage monitoring and switching circuit includes an interface BATT, an interface 3V3MEM, an interface V_NIMH, an interface V_BOOST_IN, diodes, a two-channel diode D3111, a low-voltage detection chip, a composite switching circuit module, a MOSFET module, voltage divider resistors, and filter capacitors. Interface BATT is the positive terminal of the main power supply, interface 3V3MEM is a reference voltage source providing the switching threshold reference voltage, interface V_NIMH is the positive terminal of the backup power supply, and interface V_BOOST_IN is the output interface. The diodes include D3108, D3112, D3110, and D3113. Diode D3108 is connected in series with the positive terminal of interface BATT, and one end of diode D3112 is connected to the low-voltage detection chip. Pin 3 of the low-voltage detection chip is connected, and the other end is connected to the voltage divider resistor R3240. One end of diode D3110 is electrically connected to pin 6 of the low-voltage detection chip, and the other end is grounded. Diode D3113 is connected in parallel between the interface BATT and ground. The two-channel diode D3111 is connected in parallel with the low-voltage detection chip. Pin 3 of the two-channel diode D3111 is electrically connected to the voltage divider resistor R3240. Pins 1 and 2 of the two-channel diode D3111 are electrically connected to the input terminals of voltage divider resistors R3244 and R3245. The low-voltage detection chip has 6 pins. Pins 1, 2, and 5 of the low-voltage detection chip are grounded. Pins 4 and 6 of the low-voltage detection chip are connected to the two-channel diode D3111. Pin 3 is connected to the BATT interface. The composite switch circuit module includes transistors Q3101A and Q3101B. The MOSFET module includes transistors Q3102A, Q3102B, Q3103A, Q3103B, Q3107A, Q3107B, Q3108A, Q3108B, and Q3106. The voltage divider resistors include R3101, R3102, R3247, R3246, R3240, R3241, R3242, R3243, R3244, R3245, R3135, R3132, R3137, R3140, R3102, R3103, R3101, R3108, R3109, R3124, and R312. 0. Voltage divider resistors R3101 and R3102 are connected in series between the interface BATT and ground. Voltage divider resistors R3247 and R3246 are connected in parallel with diode D3113. Voltage divider resistor R3240 is connected in series between diode D3112 and dual-channel diode D3111. Voltage divider resistor R3241 is connected in series with pin 2 of dual-channel diode D3111. Voltage divider resistor R3242 is connected between pins 3 and 4 of the low-voltage detection chip. Voltage divider resistor R3243 is connected to pin 4 of the low-voltage detection chip. Voltage divider resistors R3244 and R3245 are connected to pins 1 and 2 of voltage divider resistor R3243 and dual-channel diode D3111, respectively. Voltage divider resistor R3135 is connected to voltage divider resistor R3241.Voltage divider resistor R3137 is connected to pin 1 of transistor Q3106; voltage divider resistor R3140 is connected between pin 1 of transistor Q3106 and ground; voltage divider resistor R3102 is connected to pin 5 of transistor Q3101A; voltage divider resistor R3103 is connected between voltage divider resistor R3102 and ground; voltage divider resistor R33101 is connected between pin 3 of transistor Q3101A and interface V_NIMH; voltage divider resistor R3108 is connected between interface V_NIMH and pin 3 of transistor Q3107A; and voltage divider resistor R3120 is connected to transistor Q3107A. Pin 3 of transistor Q3107B is connected to pin 6 of transistor Q3108B. Voltage divider resistor R3124 is connected between pin 6 of transistor Q3103B and pin 6 of transistor Q3108B. Voltage divider resistor R3109 is connected between interface V_BOOST_IN and pin 3 of transistor Q3108A. Filter capacitor C3230 is connected in series between pin 1 of the low-voltage detection chip and ground; filter capacitor C3231 is connected in series between pin 4 of the low-voltage detection chip and ground; filter capacitor C3126 is connected in parallel with voltage divider resistor R3140; and filter capacitor C3127 is connected in parallel with transistor Q3106.

[0008] The low voltage detection chip integrates a reference comparator for real-time monitoring of the main power supply voltage.

[0009] Pin 5 of transistor Q3101A is connected to voltage divider resistor R3102; pin 3 of transistor Q3101A is connected to voltage divider resistor R3101; pin 4 of transistor Q3101A is grounded; pin 2 of transistor Q3101B is connected to voltage divider resistor R3101; pin 6 of transistor Q3101B is connected to voltage divider resistor R3108; pin 1 of transistor Q3101B is grounded; pin 1 of transistor Q3106 is connected to voltage divider resistor R3137; pin 2 of transistor Q3106 is grounded; pin 4 of transistor Q3106 is grounded. Pin 3 is connected to voltage divider resistor R3241. Pin 1 of transistor Q3102A is connected to interface V_BOOST_IN. Pin 2 of transistor Q3102A is connected to resistor R3124. Pins 6 and 7 of transistor Q3102A are connected to pins 3 and 8 of transistor Q3102B, respectively. Pin 4 of transistor Q3102B is connected to the positive terminal of interface V_NIMH. Pin 5 of transistor Q3102B is connected to resistor R3120. Pin 3 of transistor Q3103A is connected to resistor R3120. Pin 4 of transistor Q3103A is connected to the positive terminal of interface V_NIMH; pin 5 of transistor Q3103A is connected to resistor R33108; pin 1 of transistor Q3103B is connected to interface V_BOOST_IN; pin 2 of transistor Q3103B is connected to resistor R3109; pin 6 of transistor Q3103B is connected to resistor R3124; pin 3 of transistor Q3107A is connected to resistor R3108; pin 4 of transistor Q3107A is grounded; pin 5 of transistor Q3107A is connected to resistor R3241; and pin 4 of transistor Q3107A is connected to ground. Pin 1 of transistor Q3107B is grounded. Pin 2 of transistor Q3107B is connected to resistor R3108. Pin 6 of transistor Q3107B is connected to resistor R3120. Pin 3 of transistor Q3108A is connected to resistor R3109. Pin 4 of transistor Q3108A is grounded. Pin 5 of transistor Q3108A is connected to resistor R3241. Pin 1 of transistor Q3108B is grounded. Pin 2 of transistor Q3108B is connected to resistor R3109. Pin 6 of transistor Q3108B is connected to resistor R3124.

[0010] The backup battery input circuit includes an interface V_NIMH, an interface 3V3LevelShift, an interface NIMH_NTC_ADC, resistors R3005 and R3006, filter capacitors C3009 and C3010, a ferrite bead FB3001, an ESD transistor D3005, and a connector J3003. Connector J3003 has five pins. The V_NIMH interface is the backup power input, the 3V3LevelShift interface is a level conversion interface, and the NIMH_NTC_ADC interface is used to connect to the battery's NTC. Filter capacitors C3009 and C3010 are connected in parallel. One end is connected to the positive terminal of interface V_NIMH, and the other end is connected to the ground. One end of the ferrite bead FB3001 is connected to the output terminal of the parallel filter capacitors C3009 and C3010, and the other end is connected to a pin of connector J3003. The cathode of the ESD protection diode D3005 is connected to a pin of connector J3003, and the anode is connected to the ground. Connector J3003 has multiple pins. Pin 3 is connected to the ferrite bead FB3001. One end of pin 2 is connected to the cathode of the ESD protection diode D3005, and the other end is connected to one end of resistors R3005 and R3006 respectively. Pins 1, 4, and 5 are grounded respectively.

[0011] The battery boost circuit includes a boost chip U3105, interfaces VBOOST_IN, MCU_Boost_EN, 5VMEM, and BOOST_VCC, an energy storage inductor L3105, filter capacitors C3145, C3143, C3141, C3151, C3152, C3153, C3172, C3128, and C3130, and resistors R3156, R3142, R3144, R3167, R3174, R3147, and R3164. The boost chip U3105 has input pins. The interface consists of SW, enable pin EN, and output pin VOUT. Interface VBOOST_IN is the positive terminal of the backup power supply. Interface VBOOST_IN is connected in series with resistor R3156 to the input pin SW of boost chip U3105. Interface MCU_Boost_EN is the enable control unit. The output of interface MCU_Boost_EN is connected in series with resistor R3142 to resistor R3144. The other end of resistor R3144 is connected to interface VBOOST_IN. Interface 5VMEM is the output interface. Interface BOOST_VCC is connected to the boost chip U3105. The VCC and MODE pins of the 3105 are connected. The energy storage inductor L3105 is connected in series between the interface VBOOST_IN and the input pin SW of the boost chip U3105. Filter capacitors C3145, C3143, and C3141 are connected in parallel between resistor R3156 and ground. Filter capacitors C3151, C3152, C3153, and C3172 are connected in parallel between the output pin VOUT of the boost chip U3105 and ground. Filter capacitor C3130 is connected between the BOOST_VCC interface and the AGN pin of the boost chip U3105. Between D, resistor R3156 is connected in series at the output terminal of interface VBOOST_IN. Resistors R3167 and R3174 are connected in series between interface 5VMEM and ground. After being connected in series, they are connected in parallel between the output voltage and ground to form a voltage divider circuit. Resistors R3142 and R3144 form the upper resistor, which is connected in series between interface MCU_Boost_EN and interface VBOOST_IN. Resistor R3147 and capacitor C3128 form a compensation network, which is connected in parallel between enable pin EN and ground. Resistor R3164 is connected in series with interface 5VMEM.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. By replacing diodes with modules composed of cascaded PMOS and NMOS transistors, the voltage drop is significantly reduced, further improving efficiency.

[0013] 2. By integrating a reference comparator inside the low-voltage detection chip, and based on the comparator threshold trigger and contactless switch design, the switching time is shortened to the millisecond level, avoiding power interruption.

[0014] 3. Multiple MOSFET modules are set in the circuit to isolate the main and backup circuits by using the reverse cutoff characteristics of the MOSFETs, thereby blocking reverse current and improving circuit safety.

[0015] 4. Integrating a TVS diode in the main power input interface circuit forms a transient voltage suppressor, which can withstand higher transient voltage surges and greatly improve safety performance.

[0016] 5. The dynamic voltage monitoring and switching circuit adopts dual power input and multi-path independent power supply, and automatically switches when any power supply fails to ensure continuous system operation. Attached Figure Description

[0017] Figure 1 This is the overall circuit diagram of the redundant power switching circuit structure of the vehicle-mounted TBOX in Embodiment 1 of the present invention.

[0018] Figure 2 This is a schematic diagram of the main power input interface circuit of the redundant power switching circuit structure of the vehicle-mounted TBOX in Embodiment 1 of the present invention.

[0019] Figure 3 This is a schematic diagram of the main power step-down converter circuit of the redundant power switching circuit structure of the vehicle-mounted TBOX in Embodiment 1 of the present invention.

[0020] Figure 4 This is a schematic diagram of the dynamic voltage monitoring and switching circuit of the redundant power switching circuit structure of the vehicle-mounted TBOX in Embodiment 1 of the present invention.

[0021] Figure 5 This is a schematic diagram of the backup battery input circuit of the redundant power switching circuit structure of the vehicle-mounted TBOX in Embodiment 1 of the present invention.

[0022] Figure 6 This is a schematic diagram of the battery boost circuit of the redundant power switching circuit structure of the vehicle-mounted TBOX in Embodiment 1 of the present invention. Detailed Implementation

[0023] To provide a better understanding of the purpose, structure, features, and functions of this utility model, detailed descriptions are provided below with reference to specific embodiments.

[0024] In this embodiment, as Figure 1As shown, the redundant power switching circuit structure of the vehicle-mounted TBOX includes a main power input interface circuit 101, a main power step-down conversion circuit 102, a dynamic voltage monitoring and switching circuit 104, a backup battery input circuit 105, a battery boost circuit 106, and a vehicle-mounted TBOX system 103. The output terminal of the main power input interface circuit is electrically connected to the input terminal of the main power step-down conversion circuit and the input terminal of the dynamic voltage monitoring and switching circuit, respectively. The output terminal of the main power step-down conversion circuit is electrically connected to the vehicle-mounted TBOX system. The output terminal of the dynamic voltage monitoring and switching circuit is electrically connected to the input terminal of the battery input circuit. The output terminal of the battery input circuit is electrically connected to the input terminal of the battery boost circuit. The input terminal of the battery boost circuit is electrically connected to the vehicle-mounted TBOX system.

[0025] The in-vehicle TBOX system 106 is existing technology, and this invention does not modify it.

[0026] like Figure 2As shown, the main power input interface circuit 101 includes interface BATT, interface VBAT, ground, power inductor L3101, filter capacitors C3101, C3102, C3103, and diodes D3101, D3102, D3103, and D3104. Interface BATT and interface VBAT are current input ports, and ground is the negative terminal of the circuit. Power inductor L3101 is connected in series between interface BATT and interface VBAT. Filter capacitors C3101, C3102, and C3103 are connected in parallel between interface VBAT and ground. Between the terminals, diode D3101 is a reverse-connection diode used to prevent reverse current flow, connected in series between interface BATT and interface VBAT, and the cathode of diode D3101 is electrically connected to filter capacitors C3102 and C3103 respectively. Diode D3102 is a TVS transient voltage suppressor used to protect the circuit, connected in parallel between interface BATT and ground. Diodes D3103 and D3104 are rectifier diodes, with diode D3104 connected in series with D3102 and diode D3103 connected in parallel with D3102. The core of the main power input interface circuit 101 consists of precision-fitted filter capacitors C3101, C3102, and C3103, and diodes D3101, D3102, D3103, and D3104. This further enhances the circuit's anti-interference capability and safety. Diode D3102 acts as a TVS transient voltage suppressor, enabling it to respond quickly to transient overvoltage conditions, limiting the overvoltage to a safe level and effectively protecting subsequent circuits from damage. To smooth the power input and reduce the impact of voltage fluctuations on the vehicle-mounted TBOX system, the circuit also incorporates a power inductor L3101 combined with capacitors C3102 and C3103. Additionally, a reverse diode D3101 is added to ensure reverse power flow. Current flows out from the positive terminal of the interface BATT, passes through the reverse diode D3101 and the power inductor L3101, and finally enters the interface VBAT, thus connecting with subsequent circuits. Other branches are connected to the negative terminal.

[0027] like Figure 3As shown, the main power supply buck converter circuit 102 includes an interface VBAT, a ground terminal, a DC-DC buck chip U3101, a filter capacitor, a voltage divider feedback resistor network, an energy storage inductor, an interface 5VDC-CDC, an interface 5VMEM, an interface 3VMEM, an MCU unit, and a freewheeling diode. The interface VBAT is the positive power supply terminal, and the ground terminal is the negative power supply terminal. Pins 1 and 2 of the DC-DC buck chip are connected to the inductor L3103, pin 3 of the DC-DC buck chip is connected to the filter C3112, pin 4 of the DC-DC buck chip is connected to the capacitor C3124, pin 5 of the DC-DC buck chip is connected to the voltage divider resistor R3117, and pins 6, 7, 9, 10, 11, and 12 of the DC-DC buck chip are connected to the filter C3112. Pins 15, 16, and 17 are grounded respectively. Pins 13 and 14 of the DC-DC step-down chip are electrically connected to the VBAT interface. Energy storage inductors include L3102 and L3103. Energy storage inductor L3102 is connected in series between the VBAT interface and pins 13 and 14 of the DC-DC step-down chip, and energy storage inductor L3103 is connected in series between pins 1 and 2 of the DC-DC step-down chip and the 5V DC-DC interface. Voltage divider resistors include R3105, R3107, R3112, R3116, R3117, R3118, R3119, R3129, R3200, R3134, R3136, R3126, R3138, R3132, and R3128. Filter capacitors include C310... 5. C3106, C3107, C3108, C3109, C3122, C3112, C3113, C3171, C3124, C3114, C3115, C3116, C3118, C3125. Voltage divider resistor R3105 is connected in series between pins 1 and 2 of the DC-DC step-down chip and ground. Voltage divider resistor R3112 is connected between pin 14 of the DC-DC step-down chip and ground. Voltage divider resistor R3116 is connected in series between the 3V3MEM interface and pin 8 of the DC-DC step-down chip. Voltage divider resistor R3117 is connected between the 5VDC-DC interface and pins 1 and 2 of the DC-DC step-down chip. Voltage divider resistor R3118 is connected to the DC-DC step-down chip... Between pin 5 and ground, voltage divider resistor R3119 is connected between the 5V DC-DC interface and voltage divider resistor R3128. Voltage divider resistors R3129 and R3200 are connected in series between pin 7 of the DC-DC step-down chip and ground. Voltage divider resistor R3134 is connected in series between pin 6 of the DC-DC step-down chip and ground. Voltage divider resistor R3136 is connected in series between pin 9 of the DC-DC step-down chip and ground. Voltage divider resistors R3126 and R3138 are connected in series between the 5V DC-DC interface and ground. Voltage divider resistor R3132 is connected between the MCU unit and the gate (G) of freewheeling diode Q3105. Voltage divider resistor R3128 is connected in series between voltage divider resistor R3119 and the drain (D) of freewheeling diode Q3105.Filter capacitor C3105 is connected in series with voltage divider resistor R3105; filter capacitors C3106 and C3109 are connected in parallel with the 5V DC-DC interface; filter capacitors C3107 and C3108 are connected in parallel with energy storage inductor L3102; filter capacitor C3122 is connected in series on pin 11 of the DC-DC step-down chip; filter capacitor C3112 is connected between pin 3 of the DC-DC step-down chip and the input terminal of energy storage inductor L3103; filter capacitor C3113 is connected in parallel with voltage divider resistor R3118; filter capacitor C3171 is connected between pin 5 of the DC-DC step-down chip and ground; filter capacitor C3124 is connected in series on pin 4 of the DC-DC step-down chip; filter capacitors C3114, C3115, and C3116 are connected in parallel between the output terminal of energy storage inductor L3103 and ground; filter capacitor C3... 118 is connected in parallel with the voltage divider resistor R3119. The filter capacitor C3125 is connected between the gate (G) of the freewheeling diode Q3105 and ground. The 5VDC-CDC interface is the power output; the 5VMEM interface is a 5V storage or specific function module power supply interface; and the 3VMEM interface is a 3.3V storage or specific function module power supply interface. The MCU unit is the control unit. The freewheeling diode is a combination switch of a PMOS and an NMOS transistor. The drain (D) and source (S) of the freewheeling diode Q3104 are connected to the 5VDC-CDC and 5VMEM interfaces, respectively. The gate (G) of the freewheeling diode Q3104 is connected to the voltage divider resistor R3128. The drain (D) of the freewheeling diode Q3105 is connected to the voltage divider resistor R3128. The gate (G) of the freewheeling diode Q3105 is connected to the filter capacitor C3125. The source (S) of the freewheeling diode Q3105 is grounded.

[0028] The main power supply buck converter circuit 102 adopts a high-efficiency DC-DC buck circuit architecture. The DC-DC buck chip, as the core component of the circuit, is responsible for bucking the 24V input voltage to ensure a stable 5V output voltage. The circuit includes capacitors C3106, C3107, C3108, and C3109 for energy storage. These capacitors provide short-term energy buffering during load changes, ensuring a stable power supply to the TBOX system even under instantaneous demand, thus guaranteeing normal system operation. A combination switch design using PMOS and NMOS transistors is employed at the power output. Controlled by the MCU control unit, this combination switch can flexibly supply power to the downstream TBOX system load. Simultaneously, it effectively prevents reverse backflow when powered by the backup battery, ensuring the safety and reliability of power switching and further enhancing the system's stability and security. The current enters the circuit from the VBAT interface, and after being buffered by the energy storage capacitor, it enters the DC-DC buck chip. The DC-DC buck chip reduces the voltage, and the current after reduction conducts from pin 8 of the DC-DC buck chip to the 3VMEM interface, and from pins 1 and 2 of the DC-DC buck chip to the 5VDCCDC interface. Then, it passes through the freewheeling diode, which is a combination switch of PMOS and NMOS transistors, and conducts to the 5VMEM interface.

[0029] like Figure 4As shown, the dynamic voltage monitoring and switching circuit 104 includes an interface BATT, an interface 3V3MEM, an interface V_NIMH, an interface V_BOOST_IN, diodes, a two-channel diode D3111, a low-voltage detection chip, a composite switching circuit module, a MOSFET module, voltage divider resistors, and filter capacitors. The BATT interface is the positive terminal of the main power supply, the 3V3MEM interface is a reference voltage source providing the switching threshold reference voltage, the V_NIMH interface is the positive terminal of the backup power supply, and the V_BOOST_IN interface is the output interface. The diodes include D3108, D3112, D3110, and D3113. Diode D3108 is connected in series with the positive terminal of the BATT interface, and one end of diode D3112 is connected to the low-voltage... Pin 3 of the detection chip is connected, and the other end is connected to the voltage divider resistor R3240. One end of diode D3110 is electrically connected to pin 6 of the low-voltage detection chip, and the other end is grounded. Diode D3113 is connected in parallel between the interface BATT and ground. The two-channel diode D3111 is connected in parallel with the low-voltage detection chip. Pin 3 of the two-channel diode D3111 is electrically connected to the voltage divider resistor R3240. Pins 1 and 2 of the two-channel diode D3111 are electrically connected to the input terminals of voltage divider resistors R3244 and R3245. The low-voltage detection chip has 6 pins. Pins 1, 2, and 5 of the low-voltage detection chip are grounded. Pins 4 and 6 of the low-voltage detection chip are connected to the two-channel diode D3111. Pin 3 of the chip is connected to the BATT interface. The composite switch circuit module includes transistors Q3101A and Q3101B. The MOSFET module includes transistors Q3102A, Q3102B, Q3103A, Q3103B, Q3107A, Q3107B, Q3108A, Q3108B, and Q3106. The voltage divider resistors include R3101, R3102, R3247, R3246, R3240, R3241, R3242, R3243, R3244, R3245, R3135, R3132, R3137, R3140, R3102, R3103, R3101, R3108, R3109, R3124, and R3106. 20. Voltage divider resistors R3101 and R3102 are connected in series between the interface BATT and ground. Voltage divider resistors R3247 and R3246 are connected in parallel with diode D3113. Voltage divider resistor R3240 is connected in series between diode D3112 and dual-channel diode D3111. Voltage divider resistor R3241 is connected in series with pin 2 of dual-channel diode D3111. Voltage divider resistor R3242 is connected between pins 3 and 4 of the low-voltage detection chip. Voltage divider resistor R3243 is connected to pin 4 of the low-voltage detection chip. Voltage divider resistors R3244 and R3245 are connected to pins 1 and 2 of voltage divider resistor R3243 and dual-channel diode D3111, respectively. Voltage divider resistor R3135 is connected to voltage divider resistor R3241.Voltage divider resistor R3137 is connected to pin 1 of transistor Q3106; voltage divider resistor R3140 is connected between pin 1 of transistor Q3106 and ground; voltage divider resistor R3102 is connected to pin 5 of transistor Q3101A; voltage divider resistor R3103 is connected between voltage divider resistor R3102 and ground; voltage divider resistor R33101 is connected between pin 3 of transistor Q3101A and interface V_NIMH; voltage divider resistor R3108 is connected between interface V_NIMH and pin 3 of transistor Q3107A; and voltage divider resistor R3120 is connected to transistor Q3107A. Pin 3 of transistor Q3107B is connected to pin 6 of transistor Q3108B. Voltage divider resistor R3124 is connected between pin 6 of transistor Q3103B and pin 6 of transistor Q3108B. Voltage divider resistor R3109 is connected between interface V_BOOST_IN and pin 3 of transistor Q3108A. Filter capacitor C3230 is connected in series between pin 1 of the low-voltage detection chip and ground; filter capacitor C3231 is connected in series between pin 4 of the low-voltage detection chip and ground; filter capacitor C3126 is connected in parallel with voltage divider resistor R3140; and filter capacitor C3127 is connected in parallel with transistor Q3106.

[0030] In this configuration, pin 5 of transistor Q3101A is connected to voltage divider resistor R3102; pin 3 of transistor Q3101A is connected to voltage divider resistor R3101; pin 4 of transistor Q3101A is grounded; pin 2 of transistor Q3101B is connected to voltage divider resistor R3101; pin 6 of transistor Q3101B is connected to voltage divider resistor R3108; pin 1 of transistor Q3101B is grounded; pin 1 of transistor Q3106 is connected to voltage divider resistor R3137; pin 2 of transistor Q3106 is grounded; and pin 4 of transistor Q3101B is grounded. Pin 3 of transistor Q3102A is connected to voltage divider resistor R3241. Pin 1 of transistor Q3102A is connected to interface V_BOOST_IN. Pin 2 of transistor Q3102A is connected to resistor R3124. Pins 6 and 7 of transistor Q3102A are connected to pins 3 and 8 of transistor Q3102B, respectively. Pin 4 of transistor Q3102B is connected to the positive terminal of interface V_NIMH. Pin 5 of transistor Q3102B is connected to resistor R3120. Pin 3 of transistor Q3103A is connected to resistor R3120. Pin 4 of transistor A is connected to the positive terminal of interface V_NIMH; pin 5 of transistor Q3103A is connected to resistor R33108; pin 1 of transistor Q3103B is connected to interface V_BOOST_IN; pin 2 of transistor Q3103B is connected to resistor R3109; pin 6 of transistor Q3103B is connected to resistor R3124; pin 3 of transistor Q3107A is connected to resistor R3108; pin 4 of transistor Q3107A is grounded; pin 5 of transistor Q3107A is connected to resistor R3241; transistor... Pin 1 of transistor Q3107B is grounded, pin 2 of transistor Q3107B is connected to resistor R3108, pin 6 of transistor Q3107B is connected to resistor R3120, pin 3 of transistor Q3108A is connected to resistor R3109, pin 4 of transistor Q3108A is grounded, pin 5 of transistor Q3108A is connected to resistor R3241, pin 1 of transistor Q3108B is grounded, pin 2 of transistor Q3108B is connected to resistor R3109, and pin 6 of transistor Q3108B is connected to resistor R3124.

[0031] The core component of the dynamic voltage monitoring and switching circuit 104 is the low-voltage detection chip U3103. The output of the low-voltage detection chip U3103 is connected to the switching circuit, which contains multiple MOSFETs. These MOSFETs collectively constitute the main switching elements of the switching circuit. When the main power supply fails, a signal triggered by a reference comparator activates the backup path, achieving seamless switching between main and backup power supplies. Multiple resistors are placed at the input and output terminals of the low-voltage detection chip for current limiting and voltage division, ensuring the normal operation of the voltage detection chip. Current enters the dynamic voltage monitoring and switching circuit 104 from the BATT interface, passes through the diode for backflow prevention and the resistor for voltage division and current limiting, and then enters the low-voltage detection chip U3103. Pin 6 of the low-voltage detection chip U3103 is then connected to the interface V_BOOST_IN. The 3V3MEM interface serves as a reference voltage source, providing a switching threshold reference voltage. When the voltage falls below the set threshold, the comparator sends a switching signal, triggering the NMOS and PMOS transistor combination module (MOSFET switching module). The MOSFET switching module activates, quickly switching to the backup power supply to ensure the continuous operation of the TBOX. The V_NIMH interface is connected to the V_BOOST_IN interface through the MOSFET switching module. Under normal conditions, the low-voltage detection chip monitors the main power supply voltage in real time, and both the BATT and V_NIMH interfaces are connected to the V_BOOST_IN interface. When the voltage falls below the set threshold, the comparator sends a switching signal, triggering the MOSFET switching module. The MOSFET switching module quickly disconnects from the BATT interface, thus ensuring the continuous operation of the TBOX. The entire switching process was seamless and rapid, avoiding TBOX malfunctions caused by power outages.

[0032] Furthermore, the low-voltage detection chip U3101 integrates a reference comparator for real-time monitoring of the main power supply voltage. The U3101 low-voltage detection chip integrates a precision comparator to monitor the main power supply voltage in real time. This chip has high sensitivity and accuracy, and can quickly trigger a switching signal when the main power supply voltage falls below a set threshold.

[0033] like Figure 5As shown, the backup battery input circuit 105 includes an interface V_NIMH, an interface 3V3LevelShift, an interface NIMH_NTC_ADC, resistors R3005 and R3006, filter capacitors C3009 and C3010, a ferrite bead FB3001, an ESD transistor D3005, and a connector J3003. Connector J3003 has five pins. The interface V_NIMH is the backup power input, the interface 3V3LevelShift is a level conversion interface, the interface NIMH_NTC_ADC is used to connect the battery's NTC, and filter capacitors C3009 and C3010 are connected in parallel. One end of the FB3001 is connected to the positive terminal of the V_NIMH interface, and the other end is connected to ground. One end of the FB3001 ferrite bead is connected to the output terminal of the parallel filter capacitors C3009 and C3010, and the other end is connected to a pin of connector J3003. The cathode of the ESD protection diode D3005 is connected to a pin of connector J3003, and the anode is connected to ground. Connector J3003 has multiple pins. Pin 3 is connected to the FB3001 ferrite bead. One end of pin 2 is connected to the cathode of the ESD protection diode D3005, and the other end is connected to one end of resistors R3005 and R3006, respectively. Pins 1, 4, and 5 are grounded. The backup battery input circuit 105 serves as a backup for the main power supply circuit, ensuring rapid power switching in the event of a main power failure. Current enters the circuit from the 3V3LevelShift interface, passes through resistor R3005, enters pin 2 of connector J3003, and then connects to the V_NIMH interface from pin 3 of connector J3003. Among them, resistor R3005 is used to limit the current and prevent excessive current from damaging circuit components; ESD transistor D3005 is used to prevent electrostatic interference during battery insertion and removal and ensure unidirectional current flow; ferrite bead FB3001 and filter capacitors C3009 and C3010 are used for filtering to reduce the impact of power supply noise on the circuit and ensure stable circuit operation.

[0034] like Figure 6As shown, the battery boost circuit 106 includes a boost chip U3105, interfaces VBOOST_IN, MCU_Boost_EN, 5VMEM, and BOOST_VCC, an energy storage inductor L3105, filter capacitors C3145, C3143, C3141, C3151, C3152, C3153, C3172, C3128, and C3130, and resistors R3156, R3142, R3144, R3167, R3174, R3147, and R3164. The boost chip U3105 is equipped with... The input pin is SW, the enable pin is EN, and the output pin is VOUT. The VBOOST_IN interface is the positive terminal of the backup power supply. The VBOOST_IN interface is connected in series with the input pin SW of the boost chip U3105 through resistor R3156. The MCU_Boost_EN interface is the enable control unit. The output of the MCU_Boost_EN interface is connected in series with resistor R3144 through resistor R3142. The other end of resistor R3144 is connected to the VBOOST_IN interface. The 5VMEM interface is the output interface. The BOOST_VCC interface is connected to the boost... The VCC and MODE pins of the U3105 chip are connected. The energy storage inductor L3105 is connected in series between the interface VBOOST_IN and the input pin SW of the boost chip U3105. Filter capacitors C3145, C3143, and C3141 are connected in parallel between resistor R3156 and ground. Filter capacitors C3151, C3152, C3153, and C3172 are connected in parallel between the output pin VOUT of the boost chip U3105 and ground. Filter capacitor C3130 is connected between the BOOST_VCC interface and pin A of the boost chip U3105. Between GND, resistor R3156 is connected in series at the output of interface VBOOST_IN. Resistors R3167 and R3174 are connected in series between interface 5VMEM and ground. After being connected in series, they are then connected in parallel between the output voltage and ground, forming a voltage divider circuit. Resistors R3142 and R3144 form a supervising resistor, connected in series between interface MCU_Boost_EN and interface VBOOST_IN. Resistor R3147 and capacitor C3128 form a compensation network, connected in parallel between enable pin EN and ground. Resistor R3164 is connected in series with interface 5VMEM. When the backup battery is used as the power source, the battery boost circuit 106 can reliably boost the battery voltage to the operating voltage level required by the system, ensuring normal operation of the system under backup power. Boost chip U3105, as the core of this circuit, is responsible for boosting the input battery voltage. Controlled by the pull-up enable signal from interface MCU_Boost_EN, this circuit ensures that the boost function is activated when needed, stabilizing the output voltage required by the system.Resistors R3156, R3142, R3144, R3147, and R3164 are used to limit the battery power supply and prevent excessive current from damaging circuit components. Resistors R3167 and R3174 are connected in series between the 5VMEM interface and ground for voltage detection and feedback control to ensure stable operation of the boost circuit. The energy storage inductor L3105 and filter capacitors C3145, C3143, C3141, C3151, C3152, C3153, C3172, and C3128 together constitute the energy storage section of the boost circuit, achieving voltage boost conversion. The main current enters the circuit from the interface VBOOST_IN, passes through the filter capacitors C3145, C3143, and C3141 and the energy storage inductor L3105, enters the SW pin of the boost chip U3105, and then flows out from the VOUT pin of the boost chip U3105. After passing through the filter capacitors C3151, C3152, C3153, and C3172, it is connected to the interface 5VMEM.

[0035] In this embodiment, seamless switching between main and backup power supplies is achieved through dynamic voltage comparison control and multi-level semiconductor switching. Parallel power supply paths and redundant circuit design eliminate the risk of single-point failures. Combined with filtering protection and anti-interference measures, the power supply reliability of the vehicle-mounted TBOX under complex operating conditions is improved. Its core innovation lies in the cooperation between the main power supply and the backup battery to avoid system shutdown due to a single power supply failure, ensuring stable operation of the vehicle-mounted TBOX under various power conditions. Furthermore, the dynamic voltage monitoring and switching circuit monitors the main power supply voltage in real time, quickly switching to the backup power supply in case of voltage fluctuations or failures, ensuring the continuity and stability of the system power supply. The main power supply buck converter circuit and the battery boost circuit respectively adapt the main power supply and backup battery voltages, ensuring normal operation of the system under different power inputs and improving power utilization and system stability.

[0036] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations will be apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. The redundant power switching circuit structure of a vehicle-mounted TBOX, characterized in that: The system includes a main power input interface circuit (101), a main power step-down converter circuit (102), a dynamic voltage monitoring and switching circuit (104), a backup battery input circuit (105), a battery boost circuit (106), and an on-board TBOX system (103). The output terminal of the main power input interface circuit (101) is electrically connected to the input terminal of the main power step-down converter circuit (102) and the input terminal of the dynamic voltage monitoring and switching circuit (104), respectively. The output terminal of the main power step-down converter circuit (102) is electrically connected to the on-board TBOX system (103). The output terminal of the dynamic voltage monitoring and switching circuit (104) is electrically connected to the input terminal of the backup battery input circuit (105). The output terminal of the backup battery input circuit (105) is electrically connected to the input terminal of the battery boost circuit (106). The input terminal of the battery boost circuit (106) is electrically connected to the on-board TBOX system (103).

2. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 1, characterized in that: The main power input interface circuit (101) includes interface BATT, interface VBAT, ground, power inductor L3101, filter capacitors C3101, C3102, C3103, and diodes D3101, D3102, D3103, and D3104. Interface BATT and interface VBAT are current input ports, ground is the negative terminal of the circuit, power inductor L3101 is connected in series between interface BATT and interface VBAT, and filter capacitors C3101, C3102, and C3103 are connected in parallel between interface VBAT and interface VBAT. Between the ground terminals, diode D3101 is a reverse connection protection diode used to prevent reverse current flow. It is connected in series between the BATT and VBAT interfaces, and the cathode of diode D3101 is electrically connected to filter capacitors C3102 and C3103 respectively. Diode D3102 is a TVS transient voltage suppressor used to protect the circuit. It is connected in parallel between the BATT interface and the ground terminal. Diodes D3103 and D3104 are rectifier diodes. Diode D3104 is connected in series with D3102, and diodes D3103 are connected in parallel with D3102.

3. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 1, characterized in that: The main power supply step-down converter circuit (102) includes an interface VBAT, a ground terminal, a DC-DC step-down chip U3101, a filter capacitor, a voltage divider feedback resistor network, an energy storage inductor, an interface 5VDC-CDC, an interface 5VMEM, an interface 3VMEM, an MCU unit, and a freewheeling diode. The interface VBAT is the positive terminal of the power supply, and the ground terminal is the negative terminal of the power supply. Pins 1 and 2 of the DC-DC step-down chip are connected to the inductor L3103, pin 3 of the DC-DC step-down chip is connected to the filter C3112, pin 4 of the DC-DC step-down chip is connected to the capacitor C3124, pin 5 of the DC-DC step-down chip is connected to the voltage divider resistor R3117, and pins 6, 7, 9, 10, 11, and 12 of the DC-DC step-down chip are connected to the filter C3112. Pins 15, 16, and 17 are grounded respectively. Pins 13 and 14 of the DC-DC step-down chip are electrically connected to the VBAT interface. Energy storage inductors include L3102 and L3103. Energy storage inductor L3102 is connected in series between the VBAT interface and pins 13 and 14 of the DC-DC step-down chip, and energy storage inductor L3103 is connected in series between pins 1 and 2 of the DC-DC step-down chip and the 5V DC-DC interface. Voltage divider resistors include R3105, R3107, R3112, R3116, R3117, R3118, R3119, R3129, R3200, R3134, R3136, R3126, R3138, R3132, and R3128. Filter capacitors include C310...

5. C3106, C3107, C3108, C3109, C3122, C3112, C3113, C3171, C3124, C3114, C3115, C3116, C3118, C3125. Voltage divider resistor R3105 is connected in series between pins 1 and 2 of the DC-DC step-down chip and ground. Voltage divider resistor R3112 is connected between pin 14 of the DC-DC step-down chip and ground. Voltage divider resistor R3116 is connected in series between the 3V3MEM interface and pin 8 of the DC-DC step-down chip. Voltage divider resistor R3117 is connected between the 5VDC-DC interface and pins 1 and 2 of the DC-DC step-down chip. Voltage divider resistor R3118 is connected to the DC-DC step-down chip... Between pin 5 and ground, voltage divider resistor R3119 is connected between the 5V DC-DC interface and voltage divider resistor R3128. Voltage divider resistors R3129 and R3200 are connected in series between pin 7 of the DC-DC step-down chip and ground. Voltage divider resistor R3134 is connected in series between pin 6 of the DC-DC step-down chip and ground. Voltage divider resistor R3136 is connected in series between pin 9 of the DC-DC step-down chip and ground. Voltage divider resistors R3126 and R3138 are connected in series between the 5V DC-DC interface and ground. Voltage divider resistor R3132 is connected between the MCU unit and the gate (G) of freewheeling diode Q3105. Voltage divider resistor R3128 is connected in series between voltage divider resistor R3119 and the drain (D) of freewheeling diode Q3105.Filter capacitor C3105 is connected in series with voltage divider resistor R3105; filter capacitors C3106 and C3109 are connected in parallel with the 5V DC-DC interface; filter capacitors C3107 and C3108 are connected in parallel with energy storage inductor L3102; filter capacitor C3122 is connected in series on pin 11 of the DC-DC step-down chip; filter capacitor C3112 is connected between pin 3 of the DC-DC step-down chip and the input terminal of energy storage inductor L3103; filter capacitor C3113 is connected in parallel with voltage divider resistor R3118; filter capacitor C3171 is connected between pin 5 of the DC-DC step-down chip and ground; filter capacitor C3124 is connected in series on pin 4 of the DC-DC step-down chip; filter capacitors C3114, C3115, and C3116 are connected in parallel between the output terminal of energy storage inductor L3103 and ground; filter capacitor C3... 118 is connected in parallel with the voltage divider resistor R3119. The filter capacitor C3125 is connected between the gate (G) of the freewheeling diode Q3105 and ground. The 5VDC-CDC interface is the power output; the 5VMEM interface is a 5V storage or specific function module power supply interface; and the 3VMEM interface is a 3.3V storage or specific function module power supply interface. The MCU unit is the control unit. The freewheeling diode is a combination switch of a PMOS and an NMOS transistor. The drain (D) and source (S) of the freewheeling diode Q3104 are connected to the 5VDC-CDC and 5VMEM interfaces, respectively. The gate (G) of the freewheeling diode Q3104 is connected to the voltage divider resistor R3128. The drain (D) of the freewheeling diode Q3105 is connected to the voltage divider resistor R3128. The gate (G) of the freewheeling diode Q3105 is connected to the filter capacitor C3125. The source (S) of the freewheeling diode Q3105 is grounded.

4. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 1, characterized in that: The dynamic voltage monitoring and switching circuit (104) includes an interface BATT, an interface 3V3MEM, an interface V_NIMH, an interface V_BOOST_IN, diodes, a two-channel diode D3111, a low-voltage detection chip, a composite switching circuit module, a MOSFET module, voltage divider resistors, and filter capacitors. The BATT interface is the positive terminal of the main power supply, the 3V3MEM interface is a reference voltage source providing the switching threshold reference voltage, the V_NIMH interface is the positive terminal of the backup power supply, and the V_BOOST_IN interface is the output interface. The diodes include D3108, D3112, D3110, and D3113. Diode D3108 is connected in series with the positive terminal of the BATT interface, and one end of diode D3112 is connected to the low-voltage... Pin 3 of the detection chip is connected, and the other end is connected to the voltage divider resistor R3240. One end of diode D3110 is electrically connected to pin 6 of the low-voltage detection chip, and the other end is grounded. Diode D3113 is connected in parallel between the interface BATT and ground. The two-channel diode D3111 is connected in parallel with the low-voltage detection chip. Pin 3 of the two-channel diode D3111 is electrically connected to the voltage divider resistor R3240. Pins 1 and 2 of the two-channel diode D3111 are electrically connected to the input terminals of voltage divider resistors R3244 and R3245. The low-voltage detection chip has 6 pins. Pins 1, 2, and 5 of the low-voltage detection chip are grounded. Pins 4 and 6 of the low-voltage detection chip are connected to the two-channel diode D3111. Pin 3 of the chip is connected to the BATT interface. The composite switch circuit module includes transistors Q3101A and Q3101B. The MOSFET module includes transistors Q3102A, Q3102B, Q3103A, Q3103B, Q3107A, Q3107B, Q3108A, Q3108B, and Q3106. The voltage divider resistors include R3101, R3102, R3247, R3246, R3240, R3241, R3242, R3243, R3244, R3245, R3135, R3132, R3137, R3140, R3102, R3103, R3101, R3108, R3109, R3124, and R3106.

20. Voltage divider resistors R3101 and R3102 are connected in series between the interface BATT and ground. Voltage divider resistors R3247 and R3246 are connected in parallel with diode D3113. Voltage divider resistor R3240 is connected in series between diode D3112 and dual-channel diode D3111. Voltage divider resistor R3241 is connected in series with pin 2 of dual-channel diode D3111. Voltage divider resistor R3242 is connected between pins 3 and 4 of the low-voltage detection chip. Voltage divider resistor R3243 is connected to pin 4 of the low-voltage detection chip. Voltage divider resistors R3244 and R3245 are connected to pins 1 and 2 of voltage divider resistor R3243 and dual-channel diode D3111, respectively. Voltage divider resistor R3135 is connected to voltage divider resistor R3241.Voltage divider resistor R3137 is connected to pin 1 of transistor Q3106; voltage divider resistor R3140 is connected between pin 1 of transistor Q3106 and ground; voltage divider resistor R3102 is connected to pin 5 of transistor Q3101A; voltage divider resistor R3103 is connected between voltage divider resistor R3102 and ground; voltage divider resistor R33101 is connected between pin 3 of transistor Q3101A and interface V_NIMH; voltage divider resistor R3108 is connected between interface V_NIMH and pin 3 of transistor Q3107A; and voltage divider resistor R3120 is connected to transistor Q3107A. Pin 3 of transistor Q3107B is connected to pin 6 of transistor Q3108B. Voltage divider resistor R3124 is connected between pin 6 of transistor Q3103B and pin 6 of transistor Q3108B. Voltage divider resistor R3109 is connected between interface V_BOOST_IN and pin 3 of transistor Q3108A. Filter capacitor C3230 is connected in series between pin 1 of the low-voltage detection chip and ground; filter capacitor C3231 is connected in series between pin 4 of the low-voltage detection chip and ground; filter capacitor C3126 is connected in parallel with voltage divider resistor R3140; and filter capacitor C3127 is connected in parallel with transistor Q3106.

5. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 4, characterized in that: The low voltage detection chip integrates a reference comparator for real-time monitoring of the main power supply voltage.

6. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 5, characterized in that: Pin 5 of transistor Q3101A is connected to voltage divider resistor R3102; pin 3 of transistor Q3101A is connected to voltage divider resistor R3101; pin 4 of transistor Q3101A is grounded; pin 2 of transistor Q3101B is connected to voltage divider resistor R3101; pin 6 of transistor Q3101B is connected to voltage divider resistor R3108; pin 1 of transistor Q3101B is grounded; pin 1 of transistor Q3106 is connected to voltage divider resistor R3137; pin 2 of transistor Q3106 is grounded; pin 4 of transistor Q3106 is grounded. Pin 3 is connected to voltage divider resistor R3241. Pin 1 of transistor Q3102A is connected to interface V_BOOST_IN. Pin 2 of transistor Q3102A is connected to resistor R3124. Pins 6 and 7 of transistor Q3102A are connected to pins 3 and 8 of transistor Q3102B, respectively. Pin 4 of transistor Q3102B is connected to the positive terminal of interface V_NIMH. Pin 5 of transistor Q3102B is connected to resistor R3120. Pin 3 of transistor Q3103A is connected to resistor R3120. Pin 4 of transistor Q3103A is connected to the positive terminal of interface V_NIMH; pin 5 of transistor Q3103A is connected to resistor R33108; pin 1 of transistor Q3103B is connected to interface V_BOOST_IN; pin 2 of transistor Q3103B is connected to resistor R3109; pin 6 of transistor Q3103B is connected to resistor R3124; pin 3 of transistor Q3107A is connected to resistor R3108; pin 4 of transistor Q3107A is grounded; pin 5 of transistor Q3107A is connected to resistor R3241; and pin 4 of transistor Q3107A is connected to ground. Pin 1 of transistor Q3107B is grounded. Pin 2 of transistor Q3107B is connected to resistor R3108. Pin 6 of transistor Q3107B is connected to resistor R3120. Pin 3 of transistor Q3108A is connected to resistor R3109. Pin 4 of transistor Q3108A is grounded. Pin 5 of transistor Q3108A is connected to resistor R3241. Pin 1 of transistor Q3108B is grounded. Pin 2 of transistor Q3108B is connected to resistor R3109. Pin 6 of transistor Q3108B is connected to resistor R3124.

7. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 1, characterized in that: The backup battery input circuit (105) includes an interface V_NIMH, an interface 3V3LevelShift, an interface NIMH_NTC_ADC, resistors R3005 and R3006, filter capacitors C3009 and C3010, a ferrite bead FB3001, an ESD transistor D3005, and a connector J3003. Connector J3003 has five pins. Interface V_NIMH is the backup power input, interface 3V3LevelShift is a level conversion interface, interface NIMH_NTC_ADC is used to connect to the battery's NTC, filter capacitors C3009 and C3010 are connected in parallel, one end connected to the positive terminal of interface V_NIMH, and the other end connected to ground. One end of the ferrite bead FB3001 is connected to the output terminal of the parallel connection of filter capacitors C3009 and C3010, and the other end is connected to connector J3003. One pin of the connector J3003 is connected to the cathode of the ESD protection diode D3005, and the anode is connected to the ground. The connector J3003 has multiple pins. Pin 3 is connected to the ferrite bead FB3001. One end of pin 2 is connected to the cathode of the ESD protection diode D3005, and the other end is connected to one end of resistors R3005 and R3006 respectively. Pins 1, 4 and 5 are grounded respectively.

8. The redundant power switching circuit structure of the vehicle-mounted TBOX according to claim 1, characterized in that: The battery boost circuit (106) includes a boost chip U3105, interfaces VBOOST_IN, MCU_Boost_EN, 5VMEM, and BOOST_VCC, an energy storage inductor L3105, filter capacitors C3145, C3143, C3141, C3151, C3152, C3153, C3172, C3128, and C3130, and resistors R3156, R3142, R3144, R3167, R3174, R3147, and R3164. The boost chip U3105 has an input... The input pin is SW, the enable pin is EN, and the output pin is VOUT. The VBOOST_IN interface is the positive terminal of the backup power supply. The VBOOST_IN interface is connected in series with the input pin SW of the boost chip U3105 through resistor R3156. The MCU_Boost_EN interface is the enable control unit. The output of the MCU_Boost_EN interface is connected in series with resistor R3144 through resistor R3142. The other end of resistor R3144 is connected to the VBOOST_IN interface. The 5VMEM interface is the output interface. The BOOST_VCC interface is connected to the boost chip... The VCC and MODE pins of the U3105 are connected. The energy storage inductor L3105 is connected in series between the interface VBOOST_IN and the input pin SW of the boost chip U3105. Filter capacitors C3145, C3143, and C3141 are connected in parallel between resistor R3156 and ground. Filter capacitors C3151, C3152, C3153, and C3172 are connected in parallel between the output pin VOUT of the boost chip U3105 and ground. Filter capacitor C3130 is connected between the BOOST_VCC interface and the AG pin of the boost chip U3105. Between ND, resistor R3156 is connected in series at the output of interface VBOOST_IN. Resistors R3167 and R3174 are connected in series between interface 5VMEM and ground. After being connected in series, they are connected in parallel between the output voltage and ground to form a voltage divider circuit. Resistors R3142 and R3144 form the upper resistor, which is connected in series between interface MCU_Boost_EN and interface VBOOST_IN. Resistor R3147 and capacitor C3128 form a compensation network, which are connected in parallel between enable pin EN and ground. Resistor R3164 is connected in series with interface 5VMEM.

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