Vehicle-mounted inverter multi-output adjustable voltage device

Abstract

The utility model discloses a kind of vehicle-mounted inverter multi-path output adjustable voltage device, including main drive circuit module, boost circuit module, current detection circuit module, over-voltage and under-voltage detection circuit module, low dropout linear regulator module and full-bridge circuit module;The input end of boost circuit module is connected with external voltage and main drive circuit module, and the input end of full-bridge circuit module is connected with output end;The input end of over-voltage and under-voltage detection circuit module is connected with boost circuit module, and main drive circuit module is connected with output end;The input end of low dropout linear regulator module is connected with the output end of over-voltage and under-voltage detection circuit module, and main drive circuit module is connected with output end;The input end of current detection circuit module is connected with the output end of full-bridge circuit module, and main drive circuit module is connected with output end;The input end of full-bridge circuit module is connected with boost circuit module and main drive circuit module respectively.The utility model output voltage can be infinitely adjusted, and output voltage range is wide;Output channel state can be switched.

Description

Technical Field

[0001] This utility model relates to the field of vehicle-mounted electronic equipment technology, specifically to a vehicle-mounted inverter with multiple output adjustable voltage. Background Technology

[0002] The rapid development of domestically produced new energy vehicles has strongly promoted the diversification and intelligentization of on-board electrical equipment. Since new energy vehicles have overcome the limitations of traditional fuel vehicles in terms of electricity usage, the power and intelligence of on-board electrical equipment are gradually increasing. Taking on-board inverters as an example, traditional fuel vehicle inverters are mostly low-power and limited in their application scenarios, with a maximum power of only around 100 watts. Inverters with higher power are beyond the capacity of the vehicle's battery and cannot discharge for extended periods. In contrast, new energy vehicle inverters are powered by the vehicle's power battery. Due to the battery's large capacity, on-board inverters can discharge for extended periods and at high power. Currently, some new energy vehicle inverters even have an external power output reaching kilowatts, far exceeding the inverter output capacity of traditional fuel vehicles. This capability provides the foundation for on-board inverters to discharge for extended periods with high power and in multiple scenarios.

[0003] However, current traditional vehicle inverters still have many technical shortcomings, making it difficult to adapt to the diversified power consumption needs of new energy vehicles. The specific shortcomings are as follows: 1. Traditional vehicle inverters generally adopt a fixed mains power output mode, and the output voltage and frequency cannot be dynamically adjusted. This cannot meet the needs of precision instruments for continuously variable voltage. Furthermore, they lack zoned transparent management functions, which makes it impossible to independently monitor or adjust the operating status of each circuit when powering multiple devices, thus reducing system adaptability and operational safety.

[0004] 2. The rigid fixed output voltage design of traditional vehicle inverters limits equipment compatibility and cannot provide stable support for special loads (such as professional tools) that require stepped voltage reduction or boost. In voltage fluctuation scenarios, it is easy to cause equipment failure or performance degradation.

[0005] 3. Traditional vehicle inverters, with their single fixed-frequency output (such as forced 50Hz / 60Hz), cannot adapt to non-standard frequency devices, leading to compatibility issues in cross-border applications or special industrial scenarios. Furthermore, they cannot optimize the operating efficiency of motor-type loads through frequency adjustment. The limited number of output circuits and their singular functional design (such as providing only standard sockets) fail to meet the diverse power supply needs of multiple devices, do not support expansion module access, and limit the scalability of the vehicle electronic ecosystem.

[0006] 4. Traditional vehicle inverters rely on physical switches for circuit state switching and lack linkage mechanisms. Users need to manually operate each circuit to adjust the power supply strategy. In emergency situations, the equipment may be shut down due to operation delays, and automated circuit management cannot be achieved through preset scenario modes. Utility Model Content

[0007] In view of this, in order to solve the problems of fixed output, poor compatibility and lack of comprehensive protection of existing vehicle inverters, this utility model proposes a vehicle inverter multi-output adjustable voltage device, which supports multiple independent outputs and zone drive, and is suitable for scenarios where multiple devices are powered at the same time; it realizes wide-range stepless adjustment of output voltage and multi-level adjustable frequency, and is compatible with different load requirements; it has a complete protection mechanism to ensure the safe operation of the equipment; and it adopts a modular design to facilitate installation, expansion and maintenance.

[0008] This utility model solves the above problems through the following technical means: This utility model provides a vehicle-mounted inverter with multiple output adjustable voltage, including a main drive circuit module, a boost circuit module, a current detection circuit module, an over / under voltage detection circuit module, a low dropout linear regulator module, and a full-bridge circuit module. The input terminal of the boost circuit module is connected to the external DC voltage and the main drive circuit module respectively, and the output terminal is connected to the input terminal of the full bridge circuit module. It is used to boost the input external voltage to the target DC voltage and output it to the full bridge circuit module through the drive of the main drive circuit module. The main drive circuit module is connected to the boost circuit module, the full-bridge circuit module, the current detection circuit module, the over / under voltage detection circuit module, and the low dropout linear regulator, respectively, and is used to realize signal acquisition, execution judgment and command output. The input terminal of the over / under voltage detection circuit module is connected to the boost circuit module, and the output terminal is connected to the main drive circuit module. It is used to detect whether the output voltage of the boost circuit module is over / under voltage. If over / under voltage is detected, an over / under voltage signal is output to the main drive circuit module. The input terminal of the low dropout linear regulator module is connected to the output terminal of the over / under voltage detection circuit module, and the output terminal is connected to the main drive circuit module. It is used to convert the input voltage into a stable DC voltage to power the main drive circuit module. The input terminal of the current detection circuit module is connected to the output terminal of the full-bridge circuit module, and the output terminal is connected to the main drive circuit module. It is used to detect the output current of the full-bridge circuit module. When the output current of the full-bridge circuit module is abnormal, the output of the full-bridge circuit module is cut off through the main drive circuit module. The input terminals of the full-bridge circuit module are connected to the boost circuit module and the main drive circuit module, respectively. It is used to receive the target DC voltage from the boost voltage module and the PWM drive signal from the main drive circuit module. By alternately switching on and off the internal MOS transistors, the target DC voltage is inverted into an AC voltage of a specified frequency for output.

[0009] Preferably, the full-bridge circuit module includes a first full-bridge circuit and a second full-bridge circuit, wherein the first full-bridge circuit and the second full-bridge circuit simultaneously output AC voltage or output AC voltage through a single channel.

[0010] Preferably, the current detection circuit module includes a first current detection circuit and a second current detection circuit. The first current detection circuit is used to detect the output current of the first full-bridge circuit, and the second current detection circuit is used to detect the output current of the second full-bridge circuit.

[0011] Preferably, the two series diodes D15 and D16 at the input terminal of the first current detection circuit protect the first current detection circuit from damage due to excessive input signal voltage; the output resistor R72 and the output capacitor C35 form a low-pass filter to stabilize the output signal of the first current detection circuit and filter out interference signals.

[0012] Preferably, the two series diodes D17 and D18 at the input of the second current detection circuit protect the second current detection circuit from damage due to excessive input signal voltage; the output resistor R83 and the output capacitor C42 form a low-pass filter to stabilize the output signal of the second current detection circuit and filter out interference signals.

[0013] Preferably, the main drive circuit module includes a chip IC6, model PIC16F18345-E / SO. Pins 11-14 of the chip IC6 are electrically connected to the input of the full-bridge circuit module, used to output complementary PWM signals to drive the switching action of the full-bridge circuit module, thereby inverting the target DC voltage output by the boost circuit module into AC voltage. Pins 9-10 of the chip IC6 are electrically connected to the switching component, used to adjust the output frequency of the full-bridge circuit module. Pins 16-17 of the chip IC6 are electrically connected to the output of the current detection circuit module, used to receive current detection signals. Pins 2-3 of the chip IC6 are electrically connected to the output of the over / under voltage detection circuit module, used to receive over / under voltage protection signals. Pin 15 of the chip IC6 is electrically connected to LED1 indicator light, used to indicate the working status of the main drive circuit module. A protection circuit is provided at the front end of pins 6-7 of the chip IC6 and is electrically connected to the CN4 debugging interface to prevent damage to the main drive circuit module due to excessive voltage during debugging.

[0014] Preferably, the boost circuit module is provided with a feedback adjustment component, which is used to adjust the output voltage of the boost circuit module.

[0015] Preferably, the feedback adjustment component includes a parallel feedback resistor and a dual in-line package (DIP) DIP switch for manually adjusting the output voltage of the boost circuit module.

[0016] Preferably, the feedback adjustment component includes an adjustable resistor to achieve stepless adjustment of the output voltage.

[0017] Preferably, the low dropout linear regulator module includes a current-limiting resistor R81, which limits the current when the current is too high, thereby protecting the low dropout linear regulator module.

[0018] Compared with the prior art, the beneficial effects of this utility model include at least the following: 1. Multiple independent outputs to adapt to complex scenarios: Two independent AC outputs are achieved through two full-bridge modules. The number of output circuits can be expanded by increasing the number of full-bridge modules (such as expanding to 4 or 6 channels). It supports simultaneous power supply and zoned drive for multiple devices (such as zoned adjustment of vehicle transparent windows, power supply for multiple professional tools), which significantly improves system adaptability.

[0019] 2. Wide voltage range adjustable, compatible with various loads: The output voltage supports three levels of adjustment: AC12-48V / 12-60V / 12-70V. It can also achieve stepless smooth adjustment by replacing the adjustable resistor, accurately matching the voltage requirements of different loads such as precision instruments and special tools, and avoiding equipment failure due to voltage mismatch.

[0020] 3. Multiple frequency options and strong cross-scenario compatibility: The output frequency covers three standard frequencies: 40Hz, 50Hz, and 60Hz, which can be compatible with electrical equipment of different power grid systems around the world. At the same time, it supports optimizing the operating efficiency of motor loads through frequency adjustment to reduce energy consumption.

[0021] 4. Comprehensive protection and safe and reliable operation: Built-in overcurrent protection (triggered by current detection module), over- and under-voltage protection (triggered by over- and under-voltage detection module), short circuit protection (triggered by current surge), and EMI protection (EMI circuit of each module) provide comprehensive protection for the safe operation of the inverter and load equipment; in case of failure, the main drive circuit module quickly cuts off the output to prevent the fault from escalating.

[0022] 5. Modular design for easy installation and expansion: Each module is independently designed with a simple structure and uses an aluminum alloy and plastic shell (which takes into account heat dissipation and shielding). It can be installed next to the rear seat, inside the door panel, in the trunk, etc.; it supports module expansion (such as adding a full bridge module or sensor module) to flexibly adapt to different vehicle usage scenarios.

[0023] 6. Excellent EMC performance and stable operation: Both the boost module and the full-bridge module have built-in EMI filter circuits to reduce the impact of electromagnetic interference on other electronic devices in the vehicle, while avoiding external interference from affecting the output stability of the inverter and meeting the electromagnetic compatibility requirements of the vehicle electronic devices. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the vehicle-mounted inverter with multiple output adjustable voltage of this utility model; Figure 2 This is a schematic diagram of the main drive circuit module of this utility model; Figure 3 This is a schematic diagram of the boost circuit module of this utility model; Figure 4 This is a schematic diagram of the first current detection circuit of this utility model; Figure 5 This is a schematic diagram of the second current detection circuit of this utility model; Figure 6 This is a schematic diagram of the over / under voltage detection circuit module and the low dropout linear regulator module of this utility model; Figure 7 This is the schematic diagram of the first full-bridge circuit of this utility model; Figure 8 This is the schematic diagram of the second full-bridge circuit of this utility model. Detailed Implementation

[0026] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the described embodiments are merely some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0027] The terms "first" and "second" used in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a system, product, or device that includes a series of components or units is not limited to the listed components or units, but may optionally include unlisted components or units, or may optionally include other components or units inherent to such products or devices. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] like Figure 1 As shown, this utility model provides a vehicle-mounted inverter with multiple output adjustable voltage, including a main drive circuit module, a boost circuit module, a current detection circuit module, an over / under voltage detection circuit module, a low dropout linear regulator module, and a full-bridge circuit module. The input terminal of the boost circuit module is connected to the external DC voltage and the main drive circuit module respectively, and the output terminal is connected to the input terminal of the full bridge circuit module. It is used to boost the input external voltage to the target DC voltage and output it to the full bridge circuit module through the drive of the main drive circuit module. The main drive circuit module is connected to the boost circuit module, the full-bridge circuit module, the current detection circuit module, the over / under voltage detection circuit module, and the low dropout linear regulator, respectively, and is used to realize signal acquisition, execution judgment and command output. The input terminal of the over / under voltage detection circuit module is connected to the boost circuit module, and the output terminal is connected to the main drive circuit module. It is used to detect whether the output voltage of the boost circuit module is over / under voltage. If over / under voltage is detected, an over / under voltage signal is output to the main drive circuit module. The input terminal of the low dropout linear regulator module is connected to the output terminal of the over / under voltage detection circuit module, and the output terminal is connected to the main drive circuit module. It is used to convert the input voltage into a stable DC voltage to power the main drive circuit module. The input terminal of the current detection circuit module is connected to the output terminal of the full-bridge circuit module, and the output terminal is connected to the main drive circuit module. It is used to detect the output current of the full-bridge circuit module. When the output current of the full-bridge circuit module is abnormal, the output of the full-bridge circuit module is cut off through the main drive circuit module. The input terminals of the full-bridge circuit module are connected to the boost circuit module and the main drive circuit module, respectively. It is used to receive the target DC voltage from the boost voltage module and the PWM drive signal from the main drive circuit module. By alternately switching on and off the internal MOS transistors, the target DC voltage is inverted into an AC voltage of a specified frequency for output.

[0029] Specifically, the full-bridge circuit module includes a first full-bridge circuit and a second full-bridge circuit, which simultaneously output AC voltage or output AC voltage through a single channel.

[0030] Specifically, the current detection circuit module includes a first current detection circuit and a second current detection circuit. The first current detection circuit is used to detect the output current of the first full-bridge circuit, and the second current detection circuit is used to detect the output current of the second full-bridge circuit.

[0031] The modules are interconnected via circuits to achieve signal exchange and energy transfer, as detailed below: Power supply chain: The external DC 9-16V input voltage is divided into two paths. One path is connected to the boost circuit module, and after boosting, it is output to the Vbus bus. The Vbus bus is connected to the power input terminals of the first full-bridge circuit and the second full-bridge circuit respectively. The other path is connected to the over- and under-voltage detection circuit module and the low dropout linear regulator module. After being regulated by the low dropout linear regulator module, it outputs a +5V DC voltage, which powers the main drive circuit module, the current detection circuit module, and the over- and under-voltage detection circuit module.

[0032] Energy input path: The DC 9-16V voltage output from the vehicle's power battery is divided into two paths: Path 1: DC9-16V → EMI circuit of boost circuit module (L1, C2, C3, R3 → boost main circuit (Q1, TL594) → Vbus bus → first full bridge circuit (Q2-Q5, IC2-IC3) → CN2 (load 1); Path 2: DC9-16V → EMI circuit of boost circuit module → boost main circuit → Vbus bus → second full bridge circuit (Q6-Q9, IC4-IC5) → CN3 (load 2); Path 3: DC9-16V → LDO unit (R81, U1) of over / under voltage detection circuit module and low dropout linear regulator module → +5V output → main drive circuit module (IC6), current detection circuit module (OPIC1A / OPIC1B), over / under voltage detection circuit module (IC7 / IC8).

[0033] Drive Link: The main drive circuit module outputs four complementary PWM signals (PWM1~PWM4), which are respectively connected to the drive chips of the first full-bridge circuit (PWM1, PWM2) and the second full-bridge circuit (PWM3, PWM4) to drive the MOSFETs of the full-bridge circuit module to switch on and off, realizing DC to AC conversion; the main drive circuit module is connected to the output terminal of the current detection module through the ISENS1 and ISENS2 pins to obtain the output current signals of the two full-bridge circuits; it is connected to the output terminal of the over- and under-voltage detection circuit module through the UL and OV pins to obtain the over- and under-voltage signals of the Vbus bus; the output frequency (40Hz / 50Hz / 60Hz) is set through the frequency adjustment switch DIPSW2, and the working status is indicated by LED1.

[0034] Drive signal path: Main drive circuit module (IC6) → PWM1 / PWM2 → first full-bridge circuit drive chip (IC2 / IC3) → drive Q2-Q5 to turn on and off; Main drive circuit module (IC6) → PWM3 / PWM4 → second full-bridge circuit drive chip (IC4 / IC5) → drive Q6-Q9 to switch on and off; Current sensing circuit module (OPIC1A) → ISENS1 → RA2 pin of main drive circuit module (IC6); Current sensing circuit module (OPIC1B) → ​​ISENS2 → RA4 pin of main drive circuit module (IC6); Over / under voltage detection circuit module (IC7) → UL → RB4 pin of main drive circuit module (IC6); Over / under voltage detection circuit module (IC8) → OV → RB5 pin of main drive circuit module (IC6); Frequency adjustment switch (DIPSW2) → RB6 / RB7 pins of the main drive circuit module (IC6) → Set the output frequency.

[0035] Protection Link: When the current detection circuit module detects an abnormal output current (overcurrent / short circuit) in the full-bridge circuit module, it outputs a signal to the main drive circuit module, which immediately cuts off the PWM signal of the corresponding full-bridge circuit. When the over / under voltage detection circuit module detects that the Vbus bus voltage exceeds the preset range (undervoltage <12V, overvoltage >70V), it outputs a signal to the main drive circuit module, which cuts off the PWM signals of all full-bridge circuits. The boost circuit module has built-in EMI circuitry and feedback regulation circuitry to ensure stable output voltage and compliance with electromagnetic compatibility standards.

[0036] Protection signal path: Current abnormality: The current detection circuit module outputs an abnormal signal → the main drive circuit module → cuts off the corresponding full-bridge PWM signal → the full-bridge circuit stops outputting; Over / under voltage: The over / under voltage detection circuit module outputs an abnormal signal → the main drive circuit module → cuts off all full-bridge PWM signals → the full-bridge circuit module stops outputting; Debugging protection: ICSP interface → R67 / R68 → D11 / D12 → Main drive circuit module → Prevent overvoltage damage.

[0037] like Figure 2 As shown, the core chip of the main drive circuit module is a PIC16F18345-E / SO, and its pin connections and functions are as follows: Power supply pins: VDD (pin 10) is connected to +5V, and VSS (pin 20) is grounded to ensure stable power supply to the chip; Drive output pins: RC2 (pin 14, PWM1) and RC3 (pin 7, PWM2) are connected to the input terminals of the driver chip of the first full-bridge circuit, and RC4 (pin 15, PWM3) and RC5 (pin 16, PWM4) are connected to the input terminals of the driver chip of the second full-bridge circuit, outputting complementary PWM signals (the dead time can be set by software to avoid MOSFETs from being turned on). Detection input pins: RA2 (pin 17, ISENS1) is connected to the output terminal of the first full-bridge circuit corresponding to the current detection circuit module; RA4 (pin 18, ISENS2) is connected to the output terminal of the second full-bridge circuit corresponding to the current detection circuit module to obtain the current detection signal; RB4 (pin 13, UL) is connected to the undervoltage output terminal of the overvoltage detection circuit module; RB5 (pin 12, 0V) is connected to the overvoltage output terminal of the undervoltage detection circuit module to obtain the overvoltage and undervoltage signals. Frequency adjustment pins: RB6 (pin 11) and RB7 (pin 10) are connected to the frequency adjustment switch DIPSW2 (CHS-02TB). The output frequency (40Hz / 50Hz / 60Hz) is set by the combination of switch states. Status indication and debugging pins: RC0 (pin 16) is connected to LED1 through current-limiting resistor R54 (820R / 0603) to indicate the working status of the main drive circuit module (blinking during normal operation, constantly on / off during faults); RA0 (pin 19, ICSPDAT) and RA1 (pin 18, ICSPCLK) are ICSP debugging interfaces used for program burning and debugging. The front end of the interface is connected in series with protection resistors R67 (22R / 0603) and R68 (22R / 0603) and diodes D11 and D12 to prevent overvoltage damage to the chip during debugging; Reset pin: Vpp / MCLR (pin 9) is connected to +5V through resistor R64 (10k / 0603) to ensure stable chip power-on reset.

[0038] The core functions of the main drive circuit module are: receiving current detection and over / under voltage detection signals, outputting PWM signals according to preset logic to drive the inverter process of the full-bridge circuit module, adjusting the output frequency and voltage, triggering fault protection action (cutting off PWM), and indicating the status through LEDs.

[0039] The main drive circuit module works as follows: 1. Power-on reset: +5V voltage provides a reset signal to the Vpp / MCLR pin of the main drive circuit module through R64 (10k / 0603). After the main drive circuit module completes the power-on reset, it initializes the state of each pin (PWM pin outputs low level, detection pin is set to input mode, and LED1 pin outputs high level).

[0040] 2. Frequency Setting: The main drive circuit module reads the switching state of DIPSW2 through pins RB6 and RB7, and sets the PWM signal frequency according to the preset logic. DIPSW2 All Off: PWM Frequency 40Hz; DIPSW2 pin 1 is closed only: PWM frequency 50Hz; DIPSW2 only has 2 pins closed: PWM frequency 60Hz; DIPSW2 fully closed: 50Hz by default.

[0041] 3. PWM Output Drive: The main drive circuit module generates two complementary PWM signals (PWM1 and PWM2 are complementary, and PWM3 and PWM4 are complementary) according to the set frequency, and outputs them to the full-bridge driver chip through the RC2, RC3, RC4 and RC5 pins; at the same time, the main drive circuit module sets the dead time of the PWM signal (0.5us) through software to avoid the simultaneous conduction (common conduction) of the upper and lower bridge arm MOSFETs of the full-bridge module, which would cause a short circuit.

[0042] 4. Signal Processing: The main drive circuit module acquires ISENS1 and ISENS2 signals (voltage signals output by the current detection module) in real time through RA2 and RA4 pins, and acquires UL and OV signals (level signals output by the over / under voltage detection module) through RB4 and RB5 pins, and processes them as follows: When the current is normal (the current corresponding to ISENS1 / ISENS2 is less than 1.2 times the rated value) and the voltage is normal (UL=low level, OV=low level): the main drive circuit module maintains PWM output, and LED1 flashes at a frequency of 1Hz (normal operation indicator). Overcurrent (current corresponding to ISENS1 / ISENS2 ≥ 1.2 times the rated value): The main drive circuit module immediately sets the PWM signal of the corresponding full bridge to low level, cuts off the output of the full bridge, and LED1 flashes at a frequency of 5Hz (overcurrent fault indication). Short circuit (current corresponding to ISENS1 / ISENS2 ≥ 3 times the rated value): The main drive circuit module immediately sets all full-bridge PWM signals to low level, cuts off all outputs, and LED1 remains lit (short circuit fault indication). Undervoltage (UL=high level) or overvoltage (OV=high level): The main drive circuit module immediately sets all full-bridge PWM signals to low level, cuts off all outputs, and LED1 remains off (overvoltage / undervoltage fault indication).

[0043] 5. Fault Recovery: After a fault occurs, the main drive circuit module checks the fault signal (ISENS1 / ISENS2, UL / OV) every 1 second. If the fault signal disappears (e.g., the overcurrent fault is cleared or the voltage returns to normal), the main drive circuit module resumes PWM output after a 2-second delay, and LED1 resumes normal flashing. If the fault persists, the fault state is maintained.

[0044] like Figure 3 As shown, the core chip of the boost circuit module is the TL594IPWR pulse width modulation chip, supplemented by MOSFETs, EMI circuits, and feedback regulation circuits. The specific structure is as follows: Input circuit: The external DC 9-16V input is filtered by an EMI filter circuit (inductor L1: 105uH / 3A, capacitor C2: 150uF / 25V / 20%, capacitor C3: 100uF / 100V / 20%, resistor R3: 4.7R / 200V / 1%) to remove electromagnetic interference and ensure stable input voltage; The boost main circuit: The drain of MOSFET Q1 (model BNX025H01L) is connected to the output terminal of the EMI circuit, the source is connected to the Vbus bus, and the gate is connected to the output pins (pins 11 and 14) of TL594. The PWM signal output by TL594 drives the MOSFET switch to realize the inductor energy storage and discharge, boosting DC9-16V to the preset voltage (corresponding to the DC bus voltage of AC12-48V / 12-60V / 12-70V). Feedback regulation circuit: Composed of voltage divider resistors R12 (18k / 0603), R13 (4.7k / 0603), R14 (4.7k / 0603) and a range switch DIPSW1 (CHS-02TB). The voltage divider nodes are connected to the feedback input terminals (pins 15 and 16) of TL594. By switching the range of DIPSW1, the voltage division ratio is changed, and the feedback voltage of TL594 is adjusted to achieve three-level regulation of the Vbus bus voltage. If DIPSW1 is replaced with an adjustable resistor (such as a 10k potentiometer), stepless adjustment of the output voltage can be achieved. Oscillation and Enable Circuit: The oscillation frequency of TL594 is set by external components C7 (0.47uF / 0603), R18 (820R / 0603), and C9 (470pF / 0603). The enable terminal (pin 4) is grounded through switch TR1 (PBSS4240DPN). When TR1 is on, the boost module is enabled; when it is off, the boost is stopped. Output and protection circuit: The output of the boost module is connected to an external extended load through connector CN1 (B02B-XASK-1). The output is connected in parallel with capacitors C5 (0.1uF / 0603) and C6 (0.1uF / 0603) to filter out high-frequency noise. The series diodes D1 and D2 (model PMEG10030ELPX) prevent reverse current surges and protect the MOSFET and TL594 chip.

[0045] The core function of the boost circuit module is to boost the DC 9-16V input voltage to the preset DC bus voltage, and to regulate the voltage through a range switch or adjustable resistor to ensure stable output voltage and good EMC performance.

[0046] The boost circuit module works as follows: 1. Power-on initialization: The vehicle power battery outputs DC9-16V. After the input noise is filtered out by the EMI circuit (L1, C2, C3, R3), one path powers the TL594 chip (VCC pin). After the TL594 is powered on, the oscillation circuit composed of C7, R18, and C9 starts to work, generating a fixed frequency oscillation signal (about 100kHz). The other path enables the TL594 through TR1 (PBSS4240DPN) (when TR1 is on, pin 4 of the TL594 is grounded, and the chip is enabled).

[0047] 2. Feedback Regulation and Boost: The TL594 acquires the voltage divider signal from the Vbus bus (composed of a voltage divider circuit consisting of R12, R13, R14, and DIPSW1) through pins 15 and 16 (feedback input) and compares it with the internal reference voltage (5V). If the Vbus voltage is lower than the preset value (such as the DC bus voltage corresponding to AC12-48V, which is about 67V), the TL594 increases the duty cycle of the output PWM, prolongs the conduction time of the MOSFET Q1, increases the energy storage of the inductor L1, and the Vbus voltage rises during discharge. If the Vbus voltage is higher than the preset value, the TL594 reduces the duty cycle of the output PWM, shortens the conduction time of the MOSFET Q1, and lowers the Vbus voltage. By switching the DIPSW1 position (e.g., position 1 corresponds to R12, position 2 corresponds to R13, and position 3 corresponds to R14), the voltage division ratio can be changed to achieve three-level adjustment of Vbus voltage (corresponding to AC12-48V / 12-60V / 12-70V). If replaced with an adjustable resistor, rotating the resistor changes the voltage division ratio to achieve stepless adjustment of Vbus voltage.

[0048] 3. EMC protection: L1 (105uH / 3A) in the EMI circuit suppresses differential mode interference, C2 and C3 (large capacity capacitors) filter out low-frequency interference, and C5 and C6 (0.1uF capacitors) filter out high-frequency interference, ensuring that the output voltage of the boost module is stable and the electromagnetic radiation meets the vehicle standards.

[0049] like Figure 4 and Figure 5 As shown, the current detection circuit module includes two independent current detection circuits (corresponding to the first full-bridge circuit and the second full-bridge circuit, respectively). The core chip of each current detection circuit uses a BA3472WFV-CE2 operational amplifier, and the specific structure is as follows: Input protection circuit: The input terminal of the detection unit is connected to the output terminal of the full-bridge circuit module, and diodes D15 and D16 (corresponding to the first full-bridge circuit) and D17 and D18 (corresponding to the second full-bridge circuit) are connected in series to prevent the operational amplifier from being damaged by excessively high input signal voltage (exceeding +5V); Signal conditioning circuit: Parallel voltage divider resistors R71 (100K / 0603) and R73 (100K / 0603) (corresponding to the first full-bridge circuit), and R81 (100K / 0603) and R84 (100K / 0603) (corresponding to the second full-bridge circuit) are connected at the input terminal to convert the full-bridge output current into a 0-3.3V voltage signal; series resistors R75 (3.3K / 0603) (corresponding to the first full-bridge circuit) and R85 (3.3K / 0603) (corresponding to the second full-bridge circuit) are connected at the feedback terminal of the operational amplifier to adjust the signal gain and ensure detection accuracy. Low-pass filter circuit: The operational amplifier output terminal is connected in series with resistor R72 (270R / 0603) and parallel with capacitor C35 (1000pF / 0603) (corresponding to the first full-bridge circuit), and R83 (270R / 0603) and C42 (1000pF / 0603) (corresponding to the second full-bridge circuit), forming an RC low-pass filter to filter out high-frequency interference signals and stabilize the output signal; Output circuit: The output terminals of the two detection units are defined as ISENS1 and ISENS2 respectively. They are connected to the RA2 and RA4 pins of the main drive circuit module through wires to transmit the detected current signal to the main drive circuit module.

[0050] The core function of the current detection circuit module is to detect the output current of the two full-bridge circuits in real time and convert the current signal into a voltage signal that can be recognized by the main drive circuit module. When the current exceeds the preset threshold (such as 1.2 times the rated current) or short circuit (current surge) is detected, an abnormal signal is output to the main drive circuit module to trigger the protection action.

[0051] The current detection circuit module works as follows (taking the detection of the first full-bridge circuit as an example): 1. Current sampling: The output current of the first full-bridge circuit passes through sampling resistors BL1 (24K) and BL2 (1R), generating a voltage drop across the sampling resistors (voltage drop = current × resistance value). This voltage drop serves as the input terminal of the current detection unit for the detection signal input.

[0052] 2. Input protection: The detection signal first passes through D15 and D16 (series diodes). If the detection signal voltage exceeds +5V (such as a sudden increase in current due to a load short circuit), the diodes will reverse and cut off to prevent excessive voltage from entering the operational amplifier BA3472WFV-CE2 and protect the chip from damage.

[0053] 3. Signal Conditioning: The protected detection signal is divided by R71 and R73 (100K voltage divider resistors) to reduce the voltage signal to the range of 0-3.3V (adapting to the ADC input range of the main drive circuit module), and then input to the non-inverting input of BA3472WFV-CE2; the operational amplifier adjusts the signal gain through R75 (3.3K feedback resistor) to ensure the sensitivity of the detection signal (e.g., a 1A change in current corresponds to a 0.1V change in voltage).

[0054] 4. Low-pass filter: The detection signal output by the operational amplifier passes through an RC low-pass filter composed of R72 (270R) and C35 (1000pF) to filter out high-frequency interference (such as PWM switching noise) in the detection signal and output a stable voltage signal (ISENS1).

[0055] 5. Signal transmission: The ISENS1 signal is transmitted to the RA2 pin of the main drive circuit module through the wire. The main drive circuit module converts the voltage signal into a digital signal through the internal ADC, calculates the corresponding full-bridge output current value, and compares it with the preset threshold to determine whether overcurrent protection is triggered.

[0056] like Figure 6As shown, the over / under voltage detection circuit module includes two voltage comparator chips, IC7 and IC8 (both model BD48K45G). The Vdd pin is connected to +5V, and the GND pin is grounded. The non-inverting input of IC7 is connected to the Vbus bus through voltage divider resistors R77 (100K / 0603) and R79 (100K / 0603), and the inverting input is connected to a +2.5V reference voltage (provided by the VREF pin of the main drive circuit module), used to detect undervoltage (when Vbus < 12V, the voltage after voltage division is < 2.5V, and IC7 outputs a high level, i.e., a UL signal). The inverting input of IC8 is connected to the Vbus bus through voltage divider resistors R78 (100K / 0603) and R80 (39K / 0603), and the non-inverting input is connected to a +2.5V reference voltage, used to detect overvoltage (when Vbus > 70V). When the voltage after voltage division is >2.5V, IC8 outputs a high level, i.e., an OV signal); the Vo pins of IC7 and IC8 are connected to the RB4 and RB5 pins of the main drive circuit module, respectively, to transmit over- and under-voltage signals. The core chip of the low dropout linear regulator (LDO) module uses the NCV1117ST50T3G linear regulator. The input is connected to an external DC 9-16V, with a series current-limiting resistor R81 (100R / 0805) to prevent excessive input current from damaging the LDO. The output is filtered by parallel capacitors C39 (10uF / 0805) and C40 (10uF / 0805) to ensure a stable +5V output voltage. The LDO's Tab pin is grounded to enhance heat dissipation and prevent overheating during prolonged operation.

[0057] The core function of the over / under voltage detection and LDO module is to provide a stable +5V power supply to each module of the system, while monitoring the Vbus bus voltage in real time. When the voltage exceeds the preset range, a protection signal is output to the main drive circuit module to trigger over / under voltage protection.

[0058] The over / under voltage detection and LDO module operation process are as follows: 1. LDO voltage regulation process: The DC 9-16V voltage output from the vehicle power battery is input to the IN pin of NCV1117ST50T3G (U1) through R81 (100R current limiting resistor). U1 regulates the input voltage to 5V and outputs it through the OUT pin. C39 and C40 (10uF capacitors) are connected in parallel at the output to filter out high-frequency noise after voltage regulation, ensuring a stable +5V output (ripple voltage <50mV). R81 limits the input current. When the input current exceeds 1A, the voltage drop across R81 increases, limiting the current input to U1 and protecting U1 from overcurrent damage. The Tab pin of U1 is grounded and dissipates heat through the casing to avoid the chip temperature from getting too high during long-term full-load operation (maximum temperature <85℃).

[0059] 2. Undervoltage detection process: The Vbus bus voltage is divided by R77 (100K) and R79 (100K). The divided voltage (Vdivided = Vbus × R79 / (R77 + R79)) is input to the non-inverting input of IC7 (BD48K45G). The inverting input of IC7 is connected to a +2.5V reference voltage (provided by the VREF pin of the main drive circuit module). When Vbus ≥ 12V, V divider = 12V × 100K / (100K + 100K) = 6V > 2.5V → IC7 outputs a low level (UL = low level), indicating that the voltage is normal; When Vbus < 12V, V divider voltage < 6V. If V divider voltage < 2.5V (corresponding to Vbus < 8.3V), IC7 outputs a high level (UL = high level), indicating an undervoltage fault, and the signal is transmitted to the main drive circuit module.

[0060] 3. Overvoltage detection process: The Vbus bus voltage is divided by R78 (100K) and R80 (39K). The divided voltage (Vdivided = Vbus × R80 / (R78 + R80)) is input to the inverting input of IC8 (BD48K45G); the non-inverting input of IC8 is connected to a +2.5V reference voltage. When Vbus≤70V, Vdivider = 70V×39K / (100K+39K)≈19.9V>2.5V → IC8 outputs a low level (0V=low level), indicating that the voltage is normal; When Vbus>70V, V divider>19.9V, IC8 outputs a high level (0V=high level), indicating an overvoltage fault, and the signal is transmitted to the main drive circuit module.

[0061] like Figure 7 and 8 As shown, the first full-bridge circuit and the second full-bridge circuit have the same structure. Taking the first full-bridge circuit as an example, the specific structure is as follows: The drive circuit includes two driver chips, IC2 and IC3 (both model LM5106MMX / NOPB). The VDD pin is connected to +12V (powered separately by the vehicle battery), and the VSS pin is grounded. The IN pin of IC2 is connected to PWM1 of the main drive circuit module, and the IN pin of IC3 is connected to PWM2 of the main drive circuit module. PWM1 and PWM2 are complementary signals (dead time 0.5-1us). The HB pin of the driver chip is connected to the source of the upper bridge arm MOSFET through the bootstrap capacitor C16 (10uF), the HO pin is connected to the gate of the upper bridge arm MOSFET, and the LO pin is connected to the gate of the lower bridge arm MOSFET, thereby achieving efficient driving of the MOSFET. Full-bridge inverter circuit: Includes four N-channel MOSFETs Q2 (upper bridge left), Q3 (upper bridge right), Q4 (lower bridge left), and Q5 (lower bridge right). The drain of the MOSFET is connected to the Vbus bus, and the source is grounded (PGND). The gate is connected to the HO and LO pins of the driver chip through current-limiting resistors R31 (22R / 0603) and R32 (22R / 0603) to limit the gate current and prevent damage to the MOSFET gate. Output and Filtering Circuit: The output of the full-bridge circuit is connected to the load via connector CN2 (B02B-XASK-1). The output is connected in series with sampling resistors BL1 (24K) and BL2 (1R) for the current detection module to acquire the current signal. The parallel capacitors C12 (100pF / 1206) and C13 (100pF / 1206) filter out high-frequency noise in the output AC signal. Power supply filtering circuit: capacitors C14 (0.1uF / 0603) and C15 (0.1uF / 0603) are connected in parallel at the +12V power supply terminal to filter out power supply noise and ensure stable operation of the driver chip.

[0062] The core function of the full-bridge circuit is to receive complementary PWM signals from the main drive circuit module, and drive the MOSFETs to alternately turn on and off via the driver chip, converting the DC voltage of the Vbus bus into AC voltage at a preset frequency (40Hz / 50Hz / 60Hz), thus achieving multiple independent outputs. The two full-bridge modules can operate simultaneously or individually to meet the diverse power supply needs of multiple loads. The operation of a full-bridge circuit is as follows (taking the first full-bridge circuit as an example): 1. Driver chip initialization: +12V voltage supplies power to driver chips IC2 and IC3. After IC2 and IC3 are powered on, the IN pin (connected to PWM1 and PWM2 of the main driver circuit module) is at a low level, the HO and LO pins output a low level, and the full-bridge MOSFETs Q2-Q5 are all cut off, with no output.

[0063] 2. PWM Drive and Inversion: When the main drive circuit module outputs PWM1 (high level) and PWM2 (low level): When the IN pin of IC2 is high, the HO pin outputs a high level and the LO pin outputs a low level. Then Q2 (left upper bridge arm) and Q5 (right lower bridge arm) are turned on. The Vbus voltage passes through Q2, the load (CN2), Q5, and PGND, forming a current loop, and the load receives a positive voltage. When the main drive circuit module outputs PWM1 (low level) and PWM2 (high level): When the IN pin of IC3 is high, the HO pin outputs a high level and the LO pin outputs a low level. Then Q3 (right upper bridge arm) and Q4 (left lower bridge arm) are turned on. The Vbus voltage passes through Q3, the load (CN2), Q4, and PGND, forming a reverse current loop, and the load receives a reverse voltage. By alternating between PWM1 and PWM2, a continuous AC voltage is obtained across the load. The frequency of the AC voltage is the same as the frequency of the PWM signal (40Hz / 50Hz / 60Hz), and the voltage amplitude is determined by the Vbus bus voltage (the higher the Vbus voltage, the higher the AC voltage amplitude).

[0064] 3. Bootstrap power supply: The HB pins of the driver chips IC2 and IC3 are powered through the bootstrap capacitor C16 (10uF). When Q5 (right lower bridge arm) is turned on, C16 is charged to +12V through Q5 to ground; when Q2 (left upper bridge arm) is turned on, C16 is discharged, providing the drive voltage for the HO pin of IC2, ensuring reliable conduction of the upper bridge arm MOSFET.

[0065] 4. Output filtering: C12 and C13 (100pF capacitors) at the full-bridge output end filter out high-frequency spike noise in the AC output, making the output voltage waveform smoother and meeting the requirements of precision loads for voltage waveform.

[0066] Typical application scenario: Adjustable transparent car windows Requirements: The vehicle's transparent window needs to achieve three zones of transparency adjustment via three independent AC voltages (AC24V, AC36V, AC48V), with a fixed frequency of 50Hz. The voltage must be infinitely adjustable, and automatic overcurrent protection is required. Application Configuration: Expand by adding one full-bridge circuit (third full-bridge circuit), which is connected in parallel with the first and second full-bridge circuits on the Vbus bus; The DIPSW1 of the boost circuit module is replaced with a 10k adjustable resistor to achieve stepless adjustment of Vbus voltage (corresponding to AC24V~AC48V). The frequency adjustment switch DIPSW2 is set to 50Hz; The outputs of the three full-bridge circuits are respectively connected to the three zone drive circuits of the vehicle windows. Working process: 1. The user sends the command "Partition 1 transparency 50%" through the vehicle's central control system → the central control system sends a drive signal to the main drive circuit module through the CAN bus; 2. After receiving the command, the main drive circuit module adjusts the voltage division ratio of the adjustable resistor (driven by the relay) so that the Vbus voltage corresponds to AC36V, and at the same time outputs PWM1 / PWM2 to drive the first full-bridge circuit to output AC36V / 50Hz voltage. 3. The current detection circuit module detects the output current of the first full-bridge circuit in real time (normal operating current is about 0.5A). If the window drive circuit is short-circuited (the current suddenly rises to 2A), the current detection circuit module outputs an abnormal signal to the main drive circuit module. 4. The main drive circuit module immediately cuts off the PWM output of the first full-bridge circuit, stops the power supply to this section, LED1 flashes alarm at 5Hz, and at the same time feeds back fault information to the central control via the CAN bus.

[0067] Installation and maintenance 1. Installation method The device of this utility model adopts a modular design, and the outer shell is made of aluminum alloy (2mm thick), with dimensions of 200mm×150mm×50mm. It can be installed in the following ways: Installation next to the rear seat: Using the mounting holes on the side of the device, fix it to the bracket under the rear seat with M4 screws. The output connectors CN2 and CN3 face outwards from the seat for easy connection to external loads. Door panel installation: The device is embedded into the reserved space of the door trim panel and fixed with clips. The output connector extends into the door panel storage compartment. The hidden installation does not take up interior space. Trunk installation: The device is fixed to the side wall of the trunk using Velcro or screws, suitable for long-term connection of high-power loads (such as car refrigerators).

[0068] Please note the following during installation: Ensure the device is insulated from onboard metal components (use insulating pads) to prevent short circuits; The output wiring harness uses shielded cable with a length not exceeding 2m to reduce signal interference; Leave at least 5cm of space around the device for heat dissipation, and avoid placing it near heat sources (such as exhaust pipes).

[0069] 2. Maintenance Points Regular inspection: Inspect the device's wiring harness (for looseness or aging) and casing (for deformation or corrosion) every 3 months to ensure there is no physical damage; Cleaning and maintenance: Clean the dust inside the heat dissipation holes of the device with compressed air every 6 months to prevent poor heat dissipation from causing the module to overheat; Troubleshooting: If the device is faulty (LED1 abnormal indicator), you can troubleshoot using the following steps: 1) Check if the input voltage (DC9-16V) is normal. If abnormal, check the vehicle battery or wiring harness. 2) Check if the LDO output voltage (+5V) is normal. If it is abnormal, replace the NCV1117ST50T3G chip. 3) Check if the diodes (D15-D18) of the current detection module are shorted. If they are, replace them with diodes of the same model. 4) Check if the MOSFETs (Q2-Q9) of the full-bridge module are conducting. If they are not conducting, replace the MOSFETs or the driver chip LM5106.

[0070] This invention is based on the requirements of multi-channel output and zoned drive. Taking the needs of new energy vehicles for shading, privacy, and projection functions of windows and sunroofs as an example, adjusting the transparency of the windows requires different levels of AC voltage. The continuous voltage output of this invention can meet the stepless adjustment in this example. Adjusting the transparency of the windows in different areas requires zoned drive. The multi-channel output of this invention can meet the requirements of zoned display. Adjusting the transparency state of the vehicle body to display the logo pattern can be achieved by combining the multi-channel output and state drive switch of this invention. This invention features multi-channel output, output state switching, output combination, and output voltage and frequency adjustment.

[0071] This inverter supports multiple independent outputs and zoned drive, allowing users to flexibly configure the number of output circuits according to actual load requirements, easily adapting to complex power consumption scenarios.

[0072] This utility model features a wide-range adjustable inverter output voltage, allowing users to freely select from three ranges: AC12-48V, 12-60V, and 12-70V. It also enables stepless and smooth adjustment of the output voltage, precisely matching the power supply needs of different devices.

[0073] This inverter supports on-demand output frequency adjustment, covering three standard frequencies: 40Hz, 50Hz, and 60Hz. It is compatible with electrical equipment of different standards worldwide, significantly improving equipment applicability.

[0074] Through the switch drive system, this utility model supports online switching of output circuit status, allowing users to adjust the on / off status of single or multiple circuits in real time and quickly respond to dynamic load changes.

[0075] This utility model supports the collaborative operation of multiple inverter modules, and can achieve functional superposition through parallel or cascade connection, which can be flexibly expanded to meet complex power supply scenarios.

[0076] This utility model incorporates multiple safety protection mechanisms, including automatic overcurrent limiting protection at the input end and immediate overvoltage cut-off protection at the output end, comprehensively ensuring the safe operation of the equipment and the stability of power supply.

[0077] This invention includes two basic output circuits, which can achieve multi-circuit output functionality through different output connection methods. The number of basic output circuits can be increased or decreased by adding or removing components.

[0078] The structural components of this utility model are made of aluminum alloy and plastic, and are used for heat dissipation and shielding of the product.

[0079] This utility model is easy to install, has a simple structure, and is convenient to install and use. It can be installed next to the rear seats of a car, inside the door panel, in the trunk, or under the seats, offering flexible installation options.

[0080] This utility model adopts a modular design, and different functions can be achieved by varying the number of modules such as switches.

[0081] This utility model has comprehensive safety protection functions, such as good electromagnetic compatibility, good heat dissipation design, input overcurrent protection, output overvoltage protection, and short circuit protection.

[0082] This invention features an input voltage range of DC 9-16V and an output voltage range of AC 12-48V / 12-60V / 12-70V. The output voltage frequency is adjustable in three settings: 40Hz, 50Hz, and 60Hz. The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A vehicle-mounted inverter with multiple output adjustable voltage, characterized in that, It includes a main drive circuit module, a boost circuit module, a current detection circuit module, an over / under voltage detection circuit module, a low dropout linear regulator module, and a full-bridge circuit module; The input terminals of the boost circuit module are connected to the external DC voltage and the main drive circuit module, respectively, and the output terminal is connected to the input terminal of the full-bridge circuit module. The main drive circuit module is connected to the boost circuit module, the full-bridge circuit module, the current detection circuit module, the over / under voltage detection circuit module, and the low dropout linear regulator, respectively. The input terminal of the over / under voltage detection circuit module is connected to the boost circuit module, and the output terminal is connected to the main drive circuit module. The input terminal of the low dropout linear regulator module is connected to the output terminal of the over / under voltage detection circuit module, and the output terminal is connected to the main drive circuit module. The input terminal of the current detection circuit module is connected to the output terminal of the full-bridge circuit module, and the output terminal is connected to the main drive circuit module. The input terminals of the full-bridge circuit module are connected to the boost circuit module and the main drive circuit module, respectively, and the output terminal outputs an AC voltage of a specified frequency.

2. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 1, characterized in that, The full-bridge circuit module includes a first full-bridge circuit and a second full-bridge circuit, which can output AC voltage simultaneously or output AC voltage individually.

3. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 2, characterized in that, The current detection circuit module includes a first current detection circuit and a second current detection circuit. The first current detection circuit is used to detect the output current of the first full-bridge circuit, and the second current detection circuit is used to detect the output current of the second full-bridge circuit.

4. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 3, characterized in that, The two series diodes D15 and D16 at the input of the first current detection circuit protect the first current detection circuit from damage due to excessive input signal voltage; the output resistor R72 and the output capacitor C35 form a low-pass filter to stabilize the output signal of the first current detection circuit and filter out interference signals.

5. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 3, characterized in that, The two series diodes D17 and D18 at the input of the second current detection circuit protect the second current detection circuit from damage due to excessive input signal voltage; the output resistor R83 and the output capacitor C42 form a low-pass filter to stabilize the output signal of the second current detection circuit and filter out interference signals.

6. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 1, characterized in that, The main drive circuit module includes a chip IC6, model PIC16F18345-E / SO. Pins 11-14 of the chip IC6 are electrically connected to the input of the full-bridge circuit module, used to output complementary PWM signals to drive the switching action of the full-bridge circuit module, thereby inverting the target DC voltage output by the boost circuit module into AC voltage. Pins 9-10 of the chip IC6 are electrically connected to the switching component, used to adjust the output frequency of the full-bridge circuit module. Pins 16-17 of the chip IC6 are electrically connected to the output of the current detection circuit module, used to receive current detection signals. Pins 2-3 of the chip IC6 are electrically connected to the output of the over / under voltage detection circuit module, used to receive over / under voltage protection signals. Pin 15 of the chip IC6 is electrically connected to LED1 indicator light, used to indicate the working status of the main drive circuit module. A protection circuit is provided at the front end of pins 6-7 of the chip IC6 and is electrically connected to the CN4 debugging interface to prevent damage to the main drive circuit module due to excessive voltage during debugging.

7. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 1, characterized in that, The boost circuit module is equipped with a feedback adjustment component, which is used to adjust the output voltage of the boost circuit module.

8. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 7, characterized in that, The feedback adjustment component includes a parallel feedback resistor and a dual in-line package (DIP) DIP switch for manually adjusting the output voltage of the boost circuit module.

9. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 7, characterized in that, The feedback regulation component includes an adjustable resistor to achieve stepless regulation of the output voltage.

10. The vehicle-mounted inverter with multiple output adjustable voltage according to claim 1, characterized in that, The low-dropout linear regulator module includes a current-limiting resistor R81, which limits the current when the current is too high, thereby protecting the low-dropout linear regulator module.

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