CPE device and circuit

Abstract

This invention discloses a CPE device and its circuitry. The device includes: a 5G cellular communication module connected to a switch group for communicating with a base station and transmitting base station data to the switch group; a switch group connected to a target interface for connecting the target interface to the 5G cellular communication module when the target interface is connected to a PC device; and a target interface for connecting to a PC device, transmitting base station data to the PC device when connected, and also for receiving configuration signals when connected to the PC device, wherein the configuration signals are signals emitted by the PC device for configuring the CPE device. This invention solves the technical problem that traditional CPE devices cannot expand to other functions.

Description

Technical Field

[0001] This invention relates to the field of computers, and more specifically, to a CPE device and circuit. Background Technology

[0002] CPE (Customer Premises Equipment) refers to connection devices used to access the Internet or typically access services on a provider's network. It serves as the boundary or bridging point between the operator's wireless cellular wide area network (WAN) and the user's local area network (LAN). Existing CPE devices connect to the operator's 5G NR / 4G LTE wireless cellular network via an antenna on one end. After conversion by the CPE device, the other end forms a wired Ethernet (typically an RJ45 port) and wireless Wi-Fi connection, providing network connectivity for users' PCs, mobile phones, smart home devices, etc. Because CPE devices need to support both wired Ethernet and wireless Wi-Fi simultaneously, at least two high-speed baseband interfaces are required. Therefore, to achieve this simultaneous support, the PCIe and USB 3.0 interfaces are completely occupied by these two functional modules, preventing the expansion of other functions. Summary of the Invention

[0003] This invention provides a CPE device and circuit to solve the technical problem that traditional CPE devices cannot be expanded with other functions.

[0004] According to one aspect of the present invention, a CPE device is provided, comprising: a 5G cellular communication module connected to a switch group for communicating with a base station and transmitting base station data to the switch group; the switch group connected to a target interface for connecting the target interface to the 5G cellular communication module when the target interface is connected to a PC device; the target interface for connecting to the PC device, transmitting base station data to the PC device when connected to the PC device, and further for receiving a configuration signal when connected to the PC device, wherein the configuration signal is a signal issued by the PC device for configuring the CPE device.

[0005] As an optional example, the switch group includes: a first switch, connected to the first USB port, the Ethernet module, and the target interface of the 5G cellular communication module respectively, for connecting the first USB port of the 5G cellular communication module to the target interface when the target interface is connected to the PC device, and connecting the first USB port of the 5G cellular communication module to the Ethernet module when the target interface is not connected to the PC device; a second switch, connected to the second USB port and a third switch of the 5G cellular communication module respectively, for connecting the second USB port of the 5G cellular communication module to the third switch when the target interface is connected to the PC device, and connecting the second USB port of the 5G cellular communication module to the Ethernet module when the target interface is not connected to the PC device; and a third switch, connected to the second switch and the target interface respectively, for connecting the second switch to the forward end of the target interface when the target interface is forward connected to the PC device, and connecting the second switch to the reverse end of the target interface when the target interface is reverse connected to the PC device.

[0006] As an optional example, the device further includes: an Ethernet module connected to an Ethernet interface, used to transmit the base station data to the Ethernet interface when connected to the first USB end and the second USB end of the 5G cellular communication module respectively; the Ethernet interface is used to transmit the base station data to the target device when connected to a target device and the Ethernet module is connected to the first USB end and the second USB end of the 5G cellular communication module, wherein the target device is any device capable of accessing the Internet.

[0007] As an optional example, the device further includes: a non-inverting step-down circuit, which is connected to the 5G cellular communication module, the switch group and the target interface respectively, for stepping down the voltage of the target interface and controlling the switch group to switch when the target interface is connected to the PC device.

[0008] As an optional example, the device further includes a logic control chip, which is connected to the third switch and the target interface respectively, for detecting the high and low voltages of the forward and reverse terminals of the target interface, and controlling the third switch to switch.

[0009] As an optional example, the device also includes a WIFI module connected to the PCI-E terminal of the 5G cellular communication module, used to modulate or demodulate the base station data and transmit it wirelessly through the antenna of the WIFI module.

[0010] According to another aspect of the present invention, a CPE circuit is provided, comprising: a 5G cellular communication module, wherein a first USB terminal of the 5G cellular communication module is connected to an input terminal of a first switch, and a second USB terminal of the 5G cellular communication module is connected to an input terminal of a second switch; the first switch, wherein a first output terminal of the first switch is connected to a positive terminal of a target interface, and a second output terminal of the first switch is connected to a first input terminal of an Ethernet module, wherein the target interface is used to connect to a PC device; the second switch, wherein a first output terminal of the second switch is connected to a second input terminal of the Ethernet module, and a second output terminal of the second switch is connected to an input terminal of a third switch; the third switch, wherein a first output terminal of the third switch is connected to a positive terminal of the target interface; and the target interface, wherein a negative terminal of the target interface is connected to a second output terminal of the third switch.

[0011] As an alternative example, when the target interface is connected in the forward direction to the PC device, the first output terminal of the first switch is turned on, the second output terminal of the first switch is turned off, the first output terminal of the second switch is turned off, the second output terminal of the second switch is turned on, the first output terminal of the third switch is turned on, and the second output terminal of the third switch is turned off.

[0012] As an optional example, when the target interface is not connected to the PC device, the first output terminal of the first switch is disconnected, the second output terminal of the first switch is connected, the first output terminal of the second switch is connected, the second output terminal of the second switch is connected, the first output terminal of the third switch is disconnected, and the second output terminal of the third switch is disconnected.

[0013] As an optional example, the circuit further includes: a non-inverting buck circuit, which is connected to the IO terminal of the 5G cellular communication module, the control terminal of the first switch, the control terminal of the second switch, and the positive terminal of the target interface, respectively; and a logic control chip, which is connected to the positive terminal of the target interface, the negative terminal of the target interface, and the control terminal of the third switch, respectively.

[0014] In this embodiment of the invention, a 5G cellular communication module is used, connected to a switch group, for communicating with a base station to transmit base station data to the switch group. The switch group is connected to a target interface, for connecting the target interface to the 5G cellular communication module when the target interface is connected to a PC device. The target interface is used to connect to the PC device, for transmitting base station data to the PC device when connected, and also for receiving a configuration signal when connected to the PC device. The configuration signal is a signal issued by the PC device for configuring the CPE device. Since the target interface of the CPE device switches to a communication state when connected to the PC device, the PC device can configure the CPE device through the target interface, thereby achieving the purpose of expanding other functions while transmitting the network, thus solving the technical problem that traditional CPE devices cannot expand other functions. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0016] Figure 1 This is a structural diagram of an optional CPE device according to an embodiment of the present invention;

[0017] Figure 2 This is a flowchart of an optional CPE device according to an embodiment of the present invention;

[0018] Figure 3 This is a structural diagram of an optional CPE circuit according to an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, apparatus, system, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, apparatus, products, or devices.

[0021] According to a first aspect of the present invention, a CPE device is provided, optionally, as... Figure 1 As shown, the above-mentioned equipment includes:

[0022] The 5G cellular communication module 102 is connected to the switch group and is used to communicate with the base station and transmit base station data to the switch group.

[0023] Switch group 104, connected to the target interface, is used to connect the target interface to the 5G cellular communication module when the target interface is connected to a PC device.

[0024] The target interface 106 is used to connect to a PC device, transmit base station data to the PC device when connected to the PC device, and also to receive configuration signals when connected to the PC device, wherein the configuration signals are signals issued by the PC device for configuring the CPE device.

[0025] Optionally, in this embodiment, the CPE device can be a 5G CPE device, the target interface can be a Type-C interface, a USB interface, an Android interface, etc., and the PC device can be a host PC. The CPE device's workflow is as follows: Figure 2 As shown, when the USB Type-C port, i.e. the target interface, on the CPE device is connected to the host PC via a USB cable, the 5G cellular module connects to the USB Type-C interface through the switch group, switching its working state to slave (master-slave communication) to perform master-slave communication. This allows the PC to configure the CPE device and transmit the received base station data to the PC.

[0026] Optionally, in this embodiment, when the target interface on the CPE device is connected to the host PC via a USB cable, the host PC can perform local upgrades on the CPE device, transmit data to the CPE device, and troubleshoot and repair the CPE device. The host PC can send AT commands to the CPE device and receive responses from the CPE device.

[0027] Optionally, in this embodiment, when the target interface of the CPE device is connected to the PC device, the working state of the USB interface of the CPE device is switched to the communication state. The PC device can configure the CPE device through the target interface, thereby achieving the purpose of expanding other functions while transmitting the network, thus solving the technical problem that traditional CPE devices cannot expand other functions.

[0028] As an optional example, the switch group includes:

[0029] The first switch is connected to the first USB port, the Ethernet module, and the target interface of the 5G cellular communication module, respectively. It is used to connect the first USB port of the 5G cellular communication module to the target interface when the target interface is connected to a PC device, and to connect the first USB port of the 5G cellular communication module to the Ethernet module when the target interface is not connected to a PC device.

[0030] The second switch is connected to the second USB port and the third switch of the 5G cellular communication module respectively. When the target interface is connected to a PC device, the second USB port of the 5G cellular communication module is connected to the third switch. When the target interface is not connected to a PC device, the second USB port of the 5G cellular communication module is connected to the Ethernet module.

[0031] The third switch is connected to the second switch and the target interface respectively. When the target interface is connected to the PC device in the forward direction, the second switch is connected to the forward end of the target interface. When the target interface is connected to the PC device in the reverse direction, the second switch is connected to the reverse end of the target interface.

[0032] Optionally, in this embodiment, the switch group includes three switches: a first switch, a second switch, and a third switch. The first switch switches between two signal paths on the first USB terminal of the 5G cellular communication module, allowing the first USB terminal of the 5G cellular communication module to be connected to an Ethernet module or a target interface. The second switch switches between two signal paths on the second USB terminal of the 5G cellular communication module, allowing the second USB terminal of the 5G cellular communication module to be connected to an Ethernet module or a target interface. The third switch switches between two signal paths on the third switch, i.e., switching the third switch to either the forward or reverse end of the target interface to achieve reversible insertion.

[0033] Optionally, in this embodiment, when the target interface is connected to the PC device in the forward direction, the first switch is switched to connect to the target interface, the second switch is switched to connect to the third switch, and the third switch is switched to connect to the forward end of the target interface. This allows the 5G cellular communication module to transmit received base station data to the PC device through the first USB port of the 5G cellular communication module and the target interface, and simultaneously transmit the data to the PC device through the second USB port of the 5G cellular communication module, the second switch, the third switch, and the target interface. When the target interface is connected to the PC device in the reverse direction, the first switch is switched to connect to the target interface, the second switch is switched to connect to the third switch, and the third switch is switched to connect to the reverse end of the target interface. This allows the 5G cellular communication module to transmit received base station data to the PC device through the first USB port of the 5G cellular communication module and the target interface, and simultaneously transmit the data to the PC device through the second USB port of the 5G cellular communication module, the second switch, the third switch, and the target interface. When the target interface is not connected to the PC device, the first switch is switched to connect to the Ethernet module, the second switch is switched to connect to the Ethernet module, and the third switch is disconnected, so that the 5G cellular communication module transmits the received base station data to the Ethernet module through the first USB end of the 5G cellular communication module and the first switch, and at the same time transmits it to the Ethernet module through the second USB end of the 5G cellular communication module and the second switch.

[0034] As an optional example, the above-mentioned device also includes:

[0035] The Ethernet module, connected to the Ethernet interface, is used to transmit base station data to the Ethernet interface when connected to the first USB end and the second USB end of the 5G cellular communication module respectively.

[0036] An Ethernet interface is used to transmit base station data to a target device when the Ethernet module is connected to the first USB port and the second USB port of the 5G cellular communication module. The target device can be any device that can access the Internet.

[0037] Optionally, in this embodiment, the CPE device further includes an Ethernet module and an Ethernet interface. When the target interface is not connected to the PC device, the first switch is switched to connect to the Ethernet module, and the second switch is switched to connect to the Ethernet module, so that the 5G cellular communication module transmits the received base station data to the Ethernet module through the first USB end of the 5G cellular communication module and the first switch, and at the same time transmits it to the Ethernet module through the second USB end of the 5G cellular communication module and the second switch. The Ethernet module re-encodes and decodes the received base station data into a wired network signal, and transmits it wiredly through the Ethernet interface and network cable.

[0038] As an optional example, the above-mentioned device also includes:

[0039] The in-phase step-down circuit is connected to the 5G cellular communication module, the switch group, and the target interface respectively. It is used to step down the voltage of the target interface when the target interface is connected to the PC device and control the switch group to switch.

[0040] Optionally, in this embodiment, the non-inverting buck circuit is generally composed of operational amplifiers. "Non-inverting" means that the signals are in phase; that is, when the input is high, the output is also high. When the input goes low, the output also goes low. The buck circuit reduces the VBUS5V voltage of the target interface to 1.8V to meet the I / O interface level requirements of the 5G cellular communication module, thereby controlling the master-slave communication switching and switch group switching of the 5G cellular communication module's USB terminal.

[0041] As an optional example, the above-mentioned device also includes:

[0042] The logic control chip is connected to the third switch and the target interface respectively. It is used to detect the voltage levels at the positive and negative terminals of the target interface and control the third switch to switch.

[0043] Optionally, in this embodiment, the logic control chip is responsible for detecting the high and low levels of the positive and negative signals in the target interface, and outputting high and low levels accordingly to indicate whether the USB cable is plugged in correctly or incorrectly, thereby controlling the synchronous switching of the third switch to realize the correct plugging and reversing of the target interface.

[0044] As an optional example, the above-mentioned device also includes:

[0045] The WIFI module is connected to the PCI-E terminal of the 5G cellular communication module. It is used to modulate or demodulate base station data and transmit it wirelessly through the antenna of the WIFI module.

[0046] Optionally, in this embodiment, the WIFI module interacts with the 5G cellular communication module via a wired connection to the PCI-E port of the 5G cellular communication module. Inside the WIFI module, the base station data is modulated or demodulated into a 2.4GHz or 5GHz wireless WIFI signal, which is then wirelessly transmitted through the WIFI antenna.

[0047] It should be noted that, for the sake of simplicity, the foregoing device embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0048] According to another aspect of the embodiments of this application, a CPE circuit is also provided, such as... Figure 3 As shown, it includes:

[0049] The 5G cellular communication module 302 has a first USB terminal connected to the input terminal of a first switch, and a second USB terminal connected to the input terminal of a second switch.

[0050] The first switch 304 has its first output terminal connected to the positive terminal of the target interface, and its second output terminal connected to the first input terminal of the Ethernet module. The target interface is used to connect to a PC device.

[0051] The second switch 306 has its first output terminal connected to the second input terminal of the Ethernet module, and its second output terminal connected to the input terminal of the third switch.

[0052] The third switch 308 has its first output terminal connected to the positive terminal of the target interface.

[0053] The target interface 310 is connected to the second output terminal of the third switch via its reverse terminal.

[0054] Optionally, in this embodiment, the 5G cellular communication module includes a first USB terminal, a second USB terminal, an IO terminal, and a PCI-E terminal. The first USB terminal is connected to the input terminal of a first switch, the second USB terminal is connected to the input terminal of a second switch, the IO terminal is connected to a non-inverting buck circuit, and the PCI-E terminal is connected to a WIFI module. The first switch includes an input terminal, a first output terminal, and a second output terminal. The input terminal is connected to the first USB terminal of the 5G cellular communication module and the non-inverting buck circuit, the first output terminal is connected to the positive terminal of the target interface, and the second output terminal is connected to the first input terminal of the Ethernet module. The second switch includes an input terminal, a first output terminal, and a second output terminal. The input terminal is connected to the second USB terminal of the 5G cellular communication module and the non-inverting buck circuit, the first output terminal is connected to the second input terminal of the Ethernet module, and the second output terminal is connected to the input terminal of a third switch. The second switch also includes an input terminal, a first output terminal, and a second output terminal. The input terminal is connected to the second output terminal of the second switch, the first output terminal is connected to the positive terminal of the target interface, and the second output terminal is connected to the negative terminal of the target interface. The target interface includes a positive terminal and a negative terminal. The positive terminal is connected to the first output terminal of the third switch, and the negative terminal is connected to the second output terminal of the third switch.

[0055] As an alternative example, when the target interface is connected to the PC device in the forward direction, the first output terminal of the first switch is turned on, the second output terminal of the first switch is turned off, the first output terminal of the second switch is turned off, the second output terminal of the second switch is turned on, the first output terminal of the third switch is turned on, and the second output terminal of the third switch is turned off.

[0056] Optionally, in this embodiment, when the target interface is connected to the PC device in the forward direction, the first switch is switched to connect to the target interface, the second switch is switched to connect to the third switch, and the third switch is switched to connect to the forward end of the target interface, so that the 5G cellular communication module transmits the received base station data to the PC device through the first USB end of the 5G cellular communication module and the target interface, and at the same time transmits it to the PC device through the second USB end of the 5G cellular communication module, the second switch, the third switch, and the target interface.

[0057] As an optional example, when the target interface is not connected to the PC device, the first output terminal of the first switch is disconnected, the second output terminal of the first switch is connected, the first output terminal of the second switch is connected, the second output terminal of the second switch is connected, the first output terminal of the third switch is disconnected, and the second output terminal of the third switch is disconnected.

[0058] Optionally, in this embodiment, when the target interface is not connected to the PC device, the first switch is switched to connect to the Ethernet module, the second switch is switched to connect to the Ethernet module, and the third switch is disconnected, so that the 5G cellular communication module transmits the received base station data to the Ethernet module through the first USB end of the 5G cellular communication module and the first switch, and at the same time transmits it to the Ethernet module through the second USB end of the 5G cellular communication module and the second switch.

[0059] As an optional example, the circuit described above also includes:

[0060] The in-phase buck circuit is connected to the IO terminal of the 5G cellular communication module, the control terminal of the first switch, the control terminal of the second switch, and the positive terminal of the target interface, respectively.

[0061] The logic control chip is connected to the positive terminal of the target interface, the negative terminal of the target interface, and the control terminal of the third switch, respectively.

[0062] Optionally, in this embodiment, the non-inverting buck circuit is generally composed of operational amplifiers. "Non-inverting" means the signals are in phase; that is, when the input is high, the output is also high. When the input goes low, the output also goes low. The buck circuit reduces the VBUS5V voltage of the target interface to 1.8V to meet the I / O interface level requirements of the 5G cellular communication module, thereby controlling the master-slave communication switching and switch group switching of the USB end of the 5G cellular communication module. The logic control chip is responsible for detecting the high and low levels of the positive and negative signals in the target interface, and outputting corresponding high and low levels to indicate whether the USB cable is plugged in correctly or incorrectly, thereby controlling the synchronous switching of the third switch to achieve correct plugging / reverse plugging of the target interface.

[0063] For other examples of this embodiment, please refer to the examples above, which will not be repeated here.

Claims

1. A CPE device, characterized by, include: A 5G cellular communication module, connected to a switch group, is used to communicate with a base station and transmit base station data to the switch group; The switch group is connected to the target interface and is used to connect the target interface to the 5G cellular communication module when the target interface is connected to a PC device. The target interface is used to connect to the PC device, and when connected to the PC device, transmits the base station data to the PC device. It is also used to receive configuration signals when connected to the PC device, wherein the configuration signals are signals sent by the PC device for configuring the CPE device, and the configuration signals include local upgrade, fault debugging, or sending AT commands. The target interface is also used to enable the 5G cellular communication module to transmit the received base station data to the Ethernet module of the CPE device when not connected to a PC device. The switch group includes: A first switch is connected to the first USB port, the Ethernet module, and the target interface of the 5G cellular communication module, respectively. It is used to connect the first USB port of the 5G cellular communication module to the target interface when the target interface is connected to the PC device, and to connect the first USB port of the 5G cellular communication module to the Ethernet module when the target interface is not connected to the PC device. The second switch is connected to the second USB port and the third switch of the 5G cellular communication module, respectively. When the target interface is connected to the PC device, the second USB port of the 5G cellular communication module is connected to the third switch, and when the target interface is not connected to the PC device, the second USB port of the 5G cellular communication module is connected to the Ethernet module. The third switch is connected to the second switch and the target interface respectively, and is used to connect the second switch to the positive end of the target interface when the target interface is connected to the PC device in the forward direction, and to connect the second switch to the negative end of the target interface when the target interface is connected to the PC device in the reverse direction. The device also includes: A non-inverting step-down circuit is connected to the 5G cellular communication module, the switch group, and the target interface respectively. It is used to step down the voltage of the target interface when the target interface is connected to the PC device and control the switch group to switch.

2. The apparatus of claim 1, wherein, The device also includes: An Ethernet module, connected to an Ethernet interface, is used to transmit base station data to the Ethernet interface when connected to both the first USB port and the second USB port of the 5G cellular communication module. The Ethernet interface is used to transmit base station data to the target device when the Ethernet module is connected to the target device and the Ethernet module is connected to the first USB end and the second USB end of the 5G cellular communication module, wherein the target device is any device that can access the Internet.

3. The device according to claim 1, characterized in that, The device also includes: A logic control chip, connected to the third switch and the target interface respectively, is used to detect the high and low voltages of the positive and negative terminals of the target interface and control the third switch to switch.

4. The device according to claim 1, characterized in that, The device also includes: The WIFI module is connected to the PCI-E terminal of the 5G cellular communication module and is used to modulate or demodulate the base station data and transmit it wirelessly through the antenna of the WIFI module.

5. A CPE circuit applied to the CPE device of claim 1, characterized in that, include: A 5G cellular communication module, wherein the first USB terminal of the 5G cellular communication module is connected to the input terminal of a first switch, and the second USB terminal of the 5G cellular communication module is connected to the input terminal of a second switch; The first switch has its first output terminal connected to the positive terminal of the target interface, and is used to connect the first USB interface of the 5G cellular communication module to the target interface when the target interface is connected to a PC device. The second output terminal of the first switch is connected to the first input terminal of the Ethernet module, and is used to connect the first USB terminal of the 5G cellular communication module to the Ethernet module when the target interface is not connected to the PC device. The target interface is used to connect to the PC device. The second switch has its first output terminal connected to the second input terminal of the Ethernet module, and is used to connect the second USB interface of the 5G cellular communication module to the Ethernet module when the target interface is not connected to the PC device. The second output terminal of the second switch is connected to the input terminal of the third switch, and is used to connect the second USB terminal of the 5G cellular communication module to the third switch when the target interface is connected to the PC device. The third switch has its first output terminal connected to the positive terminal of the target interface for connecting the target interface to the PC device in a positive direction, or its second output terminal connected to the negative terminal of the target interface for connecting the target interface to the PC device in a negative direction. The target interface, the positive or negative end of the target interface is connected to the third switch; The in-phase step-down circuit is connected to the 5G cellular communication module, the control terminal of the first switch, the control terminal of the second switch, and the target interface, respectively. It is used to step down the voltage of the target interface when the target interface is connected to the PC device, and to control the switching of the first switch and the second switch.

6. The circuit according to claim 5, characterized in that, When the target interface is positively connected to the PC device, the first output terminal of the first switch is turned on, the second output terminal of the first switch is turned off, the first output terminal of the second switch is turned off, the second output terminal of the second switch is turned on, the first output terminal of the third switch is turned on, and the second output terminal of the third switch is turned off.

7. The circuit according to claim 5, characterized in that, When the target interface is not connected to the PC device, the first output terminal of the first switch is disconnected, the second output terminal of the first switch is connected, the first output terminal of the second switch is connected, the second output terminal of the second switch is connected, the first output terminal of the third switch is disconnected, and the second output terminal of the third switch is disconnected.

8. The circuit according to claim 5, characterized in that, The circuit also includes: The logic control chip is connected to the positive terminal of the target interface, the negative terminal of the target interface, and the control terminal of the third switch, respectively.

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