Vehicle-mounted USB extended audio isolation Bluetooth transmitting device

Abstract

The utility model belongs to the technical field of Bluetooth, and relates to a vehicle-mounted USB extended audio isolation Bluetooth transmitting device, which comprises a USB communication socket, a USB HUB main control chip, a USB bus adapter chip, an audio isolation transformer and an audio socket which are electrically connected. The USB communication socket is connected with the USB HUB main control chip to ensure stable transmission of data signals and is used for being connected with a vehicle or an external power supply; the USB HUB main control chip is used for communicating and controlling with the USB bus adapter chip and the audio isolation transformer; and the USB bus adapter chip is arranged between the USB HUB main control chip and the audio isolation transformer and is used for signal conversion and adaptation and converting digital audio signals from the USB HUB main control chip into signal formats suitable for being processed by the audio isolation transformer. The audio background noise can be effectively filtered and eliminated, and the Bluetooth connection compatibility of the vehicle-mounted Bluetooth equipment is better.

Description

Technical Field

[0001] The utility model relates to the technical field of Bluetooth, and more specifically, to a vehicle-mounted USB extended audio isolation Bluetooth transmitting device. Background Art

[0002] An audio Bluetooth transmitting box, as a professional audio transmission device, its main function is to wirelessly transmit the audio signals of non-Bluetooth audio devices (such as TVs, computers, CD players, etc.) to Bluetooth receiving devices such as Bluetooth headsets and Bluetooth speakers through Bluetooth technology.

[0003] In the prior art, the Bluetooth connection compatibility of the audio Bluetooth transmitting box is poor, and it often fails to connect to the Bluetooth devices of the multimedia systems in the central consoles of various brands of cars. It also cannot communicate with Android system devices through the USB interface, and there is no display operation interface for functions such as searching, pairing, and setting OTA upgrades of the Bluetooth transmitting box. The background noise of audio transmission is relatively large, and it does not support the USB interface expansion function. Usually, it only transmits audio to Bluetooth speakers or other Bluetooth home electronic devices through the Bluetooth transmitting box, with a single function and unable to meet the growing multi-functional usage needs of people. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is that in the prior art, the audio Bluetooth transmitting box usually only transmits audio to Bluetooth speakers or other Bluetooth home electronic devices through the Bluetooth transmitting box, with a single function and unable to meet the growing multi-functional usage needs of people. In view of the above-mentioned defects of the prior art, a vehicle-mounted USB extended audio isolation Bluetooth transmitting device is provided, including:

[0005] A USB communication socket, a USB HUB main control chip, a USB bus adapter chip, an audio isolation transformer, and an audio socket that are electrically connected;

[0006] The USB communication socket is connected to the USB HUB main control chip to ensure the stable transmission of data signals and is used to connect to a vehicle or an external power supply;

[0007] The USB HUB main control chip is used to communicate with and control the USB bus adapter chip and the audio isolation transformer;

[0008] The USB bus adapter chip is provided between the USB HUB main control chip and the audio isolation transformer and is used for signal conversion and adaptation to convert the digital audio signal from the USB HUB main control chip into a signal format suitable for processing by the audio isolation transformer;

[0009] The audio isolation transformer is used to achieve electrical isolation of audio signals, ensure that the audio signals are not affected by external electromagnetic interference during transmission, further process the converted audio signals, and then output them to the audio socket;

[0010] The audio socket is an output interface for audio signals, and transmits the processed audio signals to an external electronic device.

[0011] Preferably, the device further includes: a USB expansion interface for connecting to an external electronic device.

[0012] Preferably, multiple audio isolation transformers are provided.

[0013] Preferably, the device further includes: a lower cover for loading the USB communication socket, the USB HUB main control chip, the USB bus adapter chip, the audio isolation transformer, and the audio socket.

[0014] Preferably, multiple USB expansion interfaces are provided.

[0015] Preferably, two audio isolation transformers are provided, including a first audio isolation transformer and a second audio isolation transformer.

[0016] Preferably, the device further includes: an upper cover, which is arranged in cooperation with the lower cover and is used to cover the lower cover.

[0017] Preferably, the USB HUB main control chip includes any one of Genesys Logic GL850G, VIA Labs VL813, and ASMedia ASM1074.

[0018] Preferably, the USB bus adapter chip includes any one of Texas Instruments TUSB3200 and Microchip USB2514.

[0019] Preferably, the audio isolation transformer is any one of 600, TDK Lambda LA-50, and Murata Electronics DTL1000.

[0020] Implementing the in-vehicle USB expansion audio isolation Bluetooth transmitting device of the present utility model has the following beneficial effects: it can effectively filter and eliminate audio background noise, can be normally connected to the central control multimedia Bluetooth devices of various brands of cars, has better Bluetooth connection compatibility with in-vehicle Bluetooth devices, can communicate with the USB interface of the Android system, and can display the Bluetooth transmitting box search, pairing, and setting operation interface. After Bluetooth transmission through one USB interface of the Android system, it can be expanded into two USB communication interfaces. Brief Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings. The present invention will be further described below in conjunction with the drawings and embodiments. In the drawings:

[0022] Figure 1 is the overall assembly drawing of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present invention;

[0023] Figure 2 is the back view of the PCBA of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present invention;

[0024] Figure 3 is the audio background noise filtering circuit diagram of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present invention;

[0025] Figure 4 is the USB data communication circuit diagram of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present invention;

[0026] Figure 5 is the USB interface expansion circuit diagram of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present invention;

[0027] In the figures, 1 - upper cover, 2 - lower cover, 3 - USB communication socket, 4 - USB HUB main control chip, 5 - USB bus adapter chip, 6 - first audio isolation transformer, 7 - 3.5mm audio socket, 8 - second audio isolation transformer, 9 - first USB expansion interface, 10 - second USB expansion interface. Detailed Embodiment

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a certain specific posture (as shown in the attached drawings). If the specific posture changes, then the directional indications will also change accordingly.

[0030] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0031] In this embodiment, two audio isolation transformers and two USB expansion interfaces are taken as examples for illustration. Specifically in implementation, the number of audio isolation transformers and USB expansion interfaces can be determined according to actual needs, and the number of audio isolation transformers and USB expansion interfaces is not limited herein.

[0032] Figure 1 is the general assembly drawing of the in-vehicle USB expansion audio isolation Bluetooth transmitting device of the present utility model; Figure 2 is the back view of the PCBA of the in-vehicle USB expansion audio isolation Bluetooth transmitting device of the present utility model. Please refer to Figure 1 、 Figure 2 In the in-vehicle USB expansion audio isolation Bluetooth transmitting device provided in the first embodiment of the present utility model, it includes an upper cover 1, a lower cover 2, a USB communication socket 3, a USB HUB main control chip 4, a USB bus adapter chip 5, a first audio isolation transformer 6, a 3.5 mm audio socket 7, a second audio isolation transformer 8, a first USB expansion interface 9, a second USB expansion interface 10. The USB communication socket 3, the USB HUB main control chip 4, the USB bus adapter chip 5, the first audio isolation transformer 6, the 3.5 mm audio socket 7, the second audio isolation transformer 8, the first USB expansion interface 9 and the second USB expansion interface 10 are electrically connected.

[0033] The USB communication socket is connected to the USB HUB main control chip to ensure the stable transmission of data signals and is used to connect to a vehicle or an external power supply;

[0034] The USB HUB main control chip is used to communicate and control with the USB bus adapter chip and the audio isolation transformer;

[0035] The USB bus adapter chip is provided between the USB HUB master chip and the audio isolation transformer for signal conversion and adaptation, converting the digital audio signal from the USB HUB master chip into a signal format suitable for processing by the audio isolation transformer.

[0036] The audio isolation transformer is used to achieve electrical isolation of the audio signal, ensuring that the audio signal is not affected by external electromagnetic interference during transmission, further processing the converted audio signal, and then outputting it to the audio socket.

[0037] The audio socket is an output interface for the audio signal, transmitting the processed audio signal to an external electronic device. The USB communication socket is the bridge for the device to connect to the external world. It is responsible for receiving power and data signals from the vehicle or an external power source. Through the standard USB interface, users can easily connect the device to the vehicle or an external device to achieve power supply and data transmission.

[0038] The USB communication socket serves as the input interface of this device. The USB communication socket is connected to the vehicle or an external power source through a standard USB cable, providing a power and data transmission channel. This socket is directly connected to the USB HUB master chip to ensure stable transmission of data signals.

[0039] The USB HUB master chip serves as the core control unit of the entire device. The USB HUB master chip communicates and controls components such as the USB bus adapter chip and the audio isolation transformer through an internal bus. This chip is responsible for managing devices connected to the USB expansion interface, coordinating data transmission, and ensuring effective communication between devices. The USB HUB master chip is the control center of the entire device, responsible for managing and coordinating all devices connected to the USB expansion interface. This chip has powerful data processing capabilities and device management capabilities, can intelligently identify and manage connected devices, ensuring the stability and efficiency of data transmission. At the same time, it also provides a series of control commands and interfaces for other components to call and execute.

[0040] The USB bus adapter chip is located between the USB HUB master chip and the audio isolation transformer, playing a role in signal conversion and adaptation. This chip converts the digital audio signal from the USB HUB master chip into a signal format suitable for processing by the audio isolation transformer. The USB bus adapter chip plays a key role in signal conversion and adaptation in the device. Since there are significant differences in format and level between the audio signal and the USB data signal, signal conversion and adaptation are required through this chip. This chip can convert the digital audio signal from the USB HUB master chip into a signal format suitable for processing by the audio isolation transformer, ensuring accurate transmission of the audio signal.

[0041] The audio isolation transformer is used to achieve electrical isolation of audio signals, ensuring that the signals are not affected by external electromagnetic interference during transmission. The audio isolation transformer further processes the converted audio signals and then outputs them to the audio socket. The audio isolation transformer is an important component in the device for achieving electrical isolation of audio signals. It transfers the audio signals from one side to the other through the principle of electromagnetic induction while achieving electrical isolation. This isolation method can effectively prevent the influence of external electromagnetic interference on audio signals and improve the purity and stability of audio signals. In addition, the audio isolation transformer also has certain signal amplification and filtering functions, which can further optimize the processing of audio signals.

[0042] As the output interface for audio signals, the audio socket can be connected to audio devices such as headphones and speakers to transmit the processed audio signals to users. The audio socket is the interface in the device for outputting audio signals. It adopts a standard audio jack design, which can conveniently connect audio devices such as headphones and speakers. Through the audio socket, users can hear the processed and optimized audio signals and enjoy a high-quality audio experience.

[0043] The USB expansion interface provides additional USB interfaces, allowing users to connect more USB devices such as USB flash drives and Bluetooth adapters. These devices communicate with the USB HUB main control chip through the USB expansion interface to achieve data transmission and sharing. The USB expansion interface provides additional USB interfaces for the device, allowing users to connect more USB devices. These devices can communicate and transfer data with the USB HUB main control chip through the USB expansion interface. The existence of the USB expansion interface greatly expands the functions and application scope of the device, enabling users to use various USB devices more flexibly.

[0044] The USB expansion interface is used to connect external electronic devices. Multiple USB expansion interfaces are provided. In this embodiment, two are provided, including the first USB expansion interface and the second USB expansion interface.

[0045] Multiple audio isolation transformers are provided. In this embodiment, two are provided, including the first audio isolation transformer and the second audio isolation transformer.

[0046] The lower cover is used to load the USB communication socket, USB HUB main control chip, USB bus adapter chip, audio isolation transformer, and audio socket.

[0047] The upper cover is provided in cooperation with the lower cover and is used to cover the lower cover.

[0048] It should be noted that the material selection of the upper cover and the lower cover is crucial. They not only determine the durability, weight, and appearance texture of this device, but also directly affect the stability of signal transmission and the user experience. Preferably, ABS (acrylonitrile-butadiene-styrene) plastic can be used as the material for making the upper cover and the lower cover.

[0049] ABS plastic has good mechanical properties, including high impact strength and toughness, which enables the in-vehicle Bluetooth transmitter to remain stable when coping with the bumps and vibrations during vehicle driving, reducing the risk of damage caused by external forces. In addition, ABS plastic also has excellent processing properties, facilitating processes such as injection molding, which is conducive to meeting the design requirements of complex structures and precise fits.

[0050] ABS plastic has excellent insulation properties, which is particularly important for the in-vehicle USB extended audio isolation Bluetooth transmitter. Good insulation properties can effectively reduce electromagnetic interference, ensure the stability and clarity of Bluetooth signal transmission, and improve the audio transmission quality. At the same time, ABS plastic also has strong chemical corrosion resistance, capable of withstanding various chemical substances that may exist inside the vehicle, extending the service life of the product.

[0051] From the perspectives of aesthetics and cost, ABS plastic is easy to color and surface-treat, which can meet the aesthetic needs of different users. At the same time, its raw material price is moderate and the processing cost is relatively low, which is conducive to controlling the overall cost of the product and improving market competitiveness.

[0052] The USB HUB main control chip can expand a single USB interface of the vehicle into multiple ones, allowing users to connect multiple USB devices simultaneously, such as mobile phones, USB flash drives, Bluetooth adapters, etc. These chips not only support high-speed data transmission (such as a transmission rate of 5Gbps under the USB 3.0 standard), but also have good compatibility and stability, ensuring the normal operation of the connected devices. In some optional implementation methods, the USB HUB main control chip includes but is not limited to any one of Genesys Logic GL850G, VIALabs VL813, and ASMedia ASM1074.

[0053] When a USB device is connected through the expansion port, the USB HUB main control chip will automatically identify the device type and load the corresponding driver. Subsequently, the chip will manage the data transmission between devices to ensure the stability and efficiency of the data stream. Through the built-in hub technology, the chip can process the requests of multiple devices in parallel, realizing the synchronous transmission and sharing of data. In addition, these chips also support the hot plug function, allowing users to plug and unplug devices when the devices are powered on, improving the convenience of use.

[0054] The USB bus adapter chip plays a bridging role in the in-vehicle USB extended audio isolation Bluetooth transmitting device. It is responsible for converting USB signals into other types of signals or protocols for communication with different audio devices or Bluetooth modules. These chips usually have a high degree of flexibility and configurability to meet the requirements of various application scenarios. In some alternative implementation manners, the USB bus adapter chip includes but is not limited to any one of Texas Instruments TUSB3200 and Microchip USB2514. The USB bus adapter chip converts the data signal received by the USB interface into the format required by the Bluetooth module or audio processing chip through built-in conversion logic. For example, in the Bluetooth transmitting function, the adapter chip encapsulates the audio data into the format specified by the Bluetooth protocol and sends it wirelessly to the Bluetooth receiving device. At the same time, the chip is also responsible for processing the response signal of the Bluetooth receiving device to ensure smooth and stable communication. In addition, some advanced USB bus adapter chips also support audio signal processing functions such as audio decoding, amplification, and filtering to further improve the sound quality performance.

[0055] The audio isolation transformer in the in-vehicle USB extended audio isolation Bluetooth transmitting device is mainly used to achieve electrical isolation and noise suppression of audio signals. Through the isolation transformer, problems such as ground loop interference and electromagnetic radiation can be effectively avoided during the transmission of audio signals, thereby improving the purity and stability of the sound quality. In addition, the isolation transformer can also protect audio devices from electrical faults such as voltage fluctuations and short circuits to a certain extent.

[0056] In some alternative implementation manners, the audio isolation transformer includes but is not limited to any one of 600, TDK Lambda LA-50, and Murata Electronics DTL1000.

[0057] The audio isolation transformer works based on the principle of electromagnetic induction. It usually consists of a primary winding and a secondary winding, which are isolated from each other by an insulating layer. When an audio signal passes through the primary winding, a changing magnetic field is generated in the magnetic core. This magnetic field then induces a corresponding electromotive force in the secondary winding, thus realizing the transmission of the audio signal. Since there is insulation between the primary winding and the secondary winding, there is no direct electrical connection between them, thus achieving electrical isolation of the audio signal. In addition, the isolation transformer can also suppress the interference of noise and electromagnetic radiation through its internal filter circuit and shielding structure to further improve the sound quality performance.

[0058] The working principle of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present utility model is:

[0059] Power and data input, receiving power and data signals from a vehicle or an external power source through a USB communication socket. These signals are transmitted to the USB HUB main control chip for processing.

[0060] Device identification and management, the USB HUB main control chip identifies the devices connected to the USB expansion interface and manages and configures them according to the types and requirements of the devices. It ensures that each device can obtain sufficient power and bandwidth resources to achieve stable data transmission.

[0061] Signal conversion and adaptation, the USB bus adapter chip converts the digital audio signal from the USB HUB main control chip into a signal format suitable for processing by the audio isolation transformer. This step ensures the accuracy and stability of the audio signal during subsequent processing.

[0062] Electrical isolation and signal processing, the audio isolation transformer performs electrical isolation and signal processing on the converted audio signal. It uses the principle of electromagnetic induction to transmit the audio signal from one side to the other, while achieving electrical isolation and signal optimization. The processed audio signal is purer, more stable and suitable for subsequent output and playback.

[0063] Audio output and playback, the processed audio signal is output through the audio socket to the connected audio devices (such as headphones, speakers, etc.). Users can hear high-quality audio content through these devices and enjoy a pleasant audio experience.

[0064] Bluetooth transmission and connection, in addition to the above audio processing functions, the in-vehicle USB expansion audio isolation Bluetooth transmitter can also achieve Bluetooth transmission function through a Bluetooth adapter. Users can connect the Bluetooth adapter to the USB expansion interface and connect to Bluetooth devices such as mobile phones and tablets through Bluetooth. After successful connection, this device can wirelessly transmit the audio signal to these devices through Bluetooth to achieve wireless audio playback and control.

[0065] Figure 3 is the audio background noise filtering circuit diagram of the in-vehicle USB expansion audio isolation Bluetooth transmitter of the present utility model. As Figure 3 shown, the method of using two 600 audio isolation transformers is adopted to filter and eliminate the audio background noise. The left and right channel audio signals are input to the first and third pins of the audio isolation transformer. After passing through the audio isolation transformer, the audio signal is output through the fourth and fifth pins of the audio isolation transformer, and the background noise of the audio signal will be filtered and eliminated.

[0066] Figure 4 is the USB data communication circuit diagram of the in-vehicle USB expansion audio isolation Bluetooth transmitter of the present utility model. As Figure 4As shown in the figure, the Bluetooth module communicates with the USB interface of the Android system through a USB bus adapter. The USB bus adapter chip CH340G is used to implement USB data communication. The serial communication of the Bluetooth module passes through the second and third pins of the USB bus adapter chip CH340G and is converted into the fifth and sixth pins of the USB data communication chip, thus realizing communication with the USB interface of the Android system.

[0067] Figure 5 It is the USB interface expansion circuit diagram of the in-vehicle USB extended audio isolation Bluetooth transmitting device of the present utility model. As Figure 5 shown, the USB interface of the Android system realizes the USB interface expansion function through the USB2.0 HUB main control chip FE1.1s in this embodiment. The USB interface of the Android system passes through the 14th and 15th pins of the HUB chip and can realize the expansion of two USB communication interfaces through the processing of the USB2.0 HUB main control chip FE1.1s.

[0068] In specific implementation, the Bluetooth module can adopt the Qualcomm QCC3040 Bluetooth module, and the Bluetooth version 5.2 can be used, which shows better Bluetooth connection compatibility for in-vehicle Bluetooth devices.

[0069] The serial communication of the Bluetooth module passes through the second and third pins of the USB bus adapter chip CH340G and is converted into the fifth and sixth pins of the USB data communication chip, thus realizing communication with the USB interface of the Android system. Finally, the Android system software realizes the display operation interfaces such as Bluetooth transmitter box search, pairing, setting, and OTA upgrade.

[0070] The analog audio signal to be transmitted is input into the 3.5mm audio socket. After passing through the first audio isolation transformer 6 and the second audio isolation transformer 8, the background noise of the audio signal to be transmitted is filtered and eliminated, and then it enters the Bluetooth module. Then, the Bluetooth module communicates with the USB interface of the external Android system through the USB bus adapter chip 5 and the USB communication socket 3, thus realizing the Bluetooth transmitter box search, pairing, and setting operation interfaces. The USB interface of the external Android system passes through the USB communication socket 3 and the USB2.0 HUB main control chip 4, and the first USB expansion interface 9 and the second USB expansion interface 10 can be realized, thus realizing the USB interface expansion function.

[0071] Through the design of the above embodiments, the beneficial effects of the present utility model are as follows: it can effectively filter and eliminate audio background noise, can be normally connected to the central control multimedia Bluetooth devices of various brands of automobiles, has better Bluetooth connection compatibility with in-vehicle Bluetooth devices, can communicate with the USB interface of the Android system, and can display the search, pairing and setting operation interface of the Bluetooth transmitter box. After Bluetooth transmission through one USB interface of the Android system, it can be expanded into two USB communication interfaces.

[0072] The present utility model is described according to specific embodiments, but those skilled in the art should understand that various changes and equivalent replacements can be made without departing from the scope of the present utility model. In addition, in order to adapt to the specific situations of the technology of the present utility model, many modifications can be made to the present utility model without departing from its protection scope. Therefore, the present utility model is not limited to the specific embodiments disclosed herein, but includes all embodiments falling within the protection scope of the claims.

Claims

1. A vehicle-mounted USB extended audio isolation Bluetooth transmitter, characterized in that: include: Through the electrical connection of USB communication socket, USB HUB main control chip, USB bus adapter chip, audio isolation transformer, audio socket; The USB communication socket is connected to the USB HUB main control chip to ensure stable transmission of data signals and is used to connect to a vehicle or an external power source; The USB HUB main control chip is used to communicate and control with the USB bus adapter chip and the audio isolation transformer; The USB bus adapter chip is disposed between the USB HUB main control chip and the audio isolation transformer, and is used for signal conversion and adaptation, converting the digital audio signal from the USB HUB main control chip into a signal format suitable for processing by the audio isolation transformer; The audio isolation transformer is used to achieve electrical isolation of the audio signal, ensuring that the audio signal is not affected by external electromagnetic interference during transmission, further processing the converted audio signal, and then outputting it to the audio socket; The audio socket is used as an output interface of the audio signal to transmit the processed audio signal to an external electronic device.

2. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to claim 1, characterized in that: The device also includes: a USB expansion interface for connecting an external electronic device.

3. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to claim 1, characterized in that: The audio isolation transformer is provided in plurality.

4. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to claim 1, characterized in that: The device further comprises: a lower cover for loading the USB communication socket, the USB HUB main control chip, the USB bus adapter chip, the audio isolation transformer and the audio socket.

5. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to claim 2, characterized in that: The USB expansion interface is set to be multiple.

6. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to claim 3, characterized in that: The audio isolation transformers are provided in two numbers, including a first audio isolation transformer and a second audio isolation transformer.

7. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to claim 4, characterized in that: The device further comprises an upper cover, which is matched with the lower cover and used to cover the lower cover.

8. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to any one of claims 1 to 7, characterized in that: The USB HUB main control chip includes any one of Genesys Logic GL850G, VIA Labs VL813, and ASMediaASM1074.

9. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to any one of claims 1 to 7, characterized in that: The USB bus adapter chip includes any one of: Texas Instruments TUSB3200 and Microchip USB2514.

10. The vehicle-mounted USB extended audio isolation Bluetooth transmitter according to any one of claims 1 to 7, characterized in that: The audio isolation transformer is any one of 600, TDK Lambda LA-50, and Murata Electronics DTL1000.

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