4G front-end commercial power supply monitoring and control device

Abstract

The utility model relates to the technical field of circuits, in particular to a 4G front-end commercial power supply monitoring and control device. Comprising a main control module, a system power supply module, a voltage and current detection module, an alternating current voltage reduction module, a battery charging management module, a voltage detection module and a 4G internet access module, wherein the main control module is electrically connected with the 4G internet access module, the battery charging management module, the voltage detection module and the voltage and current detection module; according to the scheme, through the voltage and current detection module and the voltage detection module, key data such as voltage and current of commercial power can be collected in real time and uploaded to the main control module for processing, and commercial power supply faults can be quickly responded in combination with the emergency power supply disconnection module; and the standby battery is automatically switched to supply power or fault recovery is realized through automatic reclosing work, the power failure time is reduced, the battery charging management module ensures that the standby battery is kept in an optimal charging state in a non-fault state, and reliable power support is provided in an emergency.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of circuit design especially relates to a 4G front end commercial power supply monitoring and control device. BACKGROUND

[0002] With the rapid development of the Internet of Things technology, the Internet of Things monitoring sites are widely deployed in public safety and social governance fields. However, these sites generally use 220V commercial power supply mode, and when encountering power transient faults such as line short circuit, overload, lightning strike, etc., manual intervention or long time waiting for power supply recovery is often required. This not only seriously affects the power supply continuity of the site, but also leads to an increase in maintenance cost and a decrease in efficiency.

[0003] Traditional solutions usually use automatic reclosing switches to replace ordinary air switches to realize automatic recovery of power. However, the automatic reclosing switches on the market currently have single functions and lack networking monitoring capabilities, making it difficult to meet the needs of modern monitoring sites. For example, after the site goes offline, it is difficult to accurately determine whether the power failure is caused by commercial power supply quality problems or thunderstorm weather, which still needs to rely on manual inspection and processing, increasing the difficulty and cost of maintenance, and reducing the efficiency and response timeliness of maintenance.

[0004] Power transient faults such as short circuit, overload, and lightning strike are common causes of circuit breaker tripping, and such faults often recover automatically within a short time. Traditional devices cannot automatically detect fault recovery status and cannot provide reliable data support for analyzing and predicting fault causes. In this case, the power supply reliability and stability of the site are difficult to guarantee, thereby affecting the normal operation of the Internet of Things monitoring site. UTILITY MODEL CONTENTS

[0005] The utility model provides a 4G front end commercial power supply monitoring and control device to solve the problems existing in the prior art, which can quickly restore power supply after fault automatic elimination by combining 4G communication, big data analysis, and intelligent control technology, reduce power failure loss, and further provide deep diagnosis of power supply environment data to help analyze potential power supply risks and business anomalies.

[0006] The utility model significantly solves the pain point problems in the power supply management of the current Internet of Things monitoring site and provides an efficient and reliable technical solution for the industry.

[0007] The utility model is implemented by the following technical solutions:

[0008] A 4G front end commercial power supply monitoring and control device, comprising a main control module, a system power supply module, a voltage and current detection module, an alternating current voltage reduction module, a battery charging management module, a voltage detection module, and a 4G online module.

[0009] The master module is electrically connected with the 4G online module, the battery charging management module, the voltage detection module and the voltage and current detection module respectively.

[0010] The input end of the system power module is electrically connected with the 220V voltage input end, and the output end of the system power module is electrically connected with the input end of the battery charging management module and the input end of the voltage detection module respectively.

[0011] The input end of the voltage and current detection module is electrically connected with the 220V voltage input end.

[0012] The input end of the AC voltage reduction module is electrically connected with the 220V voltage input end, and the output end of the AC voltage reduction module is connected with the voltage input end of the voltage and current detection module.

[0013] The 4G online module is electrically connected with the master module.

[0014] Further, the emergency power disconnecting module is electrically connected with the master module.

[0015] Further, the offline data storage module and the system clock module are electrically connected with the master module.

[0016] Further, the master module comprises an MCU control chip U1, and the model of the MCU control chip U1 is STM32F103CBT6.

[0017] Further, the system power module comprises a 12V power adapter U4, the model of the 12V power adapter U4 is 220V-12B, the 1 pin of the 12V power adapter U4 is connected with the 220V live wire, the 2 pin of the 12V power adapter U4 is connected with the 220V neutral wire, the 4 pin of the 12V power adapter U4 is connected with one end of a fuse F1, and the other end of the fuse F1 is connected with a VCC voltage end.

[0018] Further, the voltage and current detection module comprises a voltage acquisition circuit, a current acquisition circuit and an electric energy metering chip U10, the model of the electric energy metering chip U10 is BL0942, the 4 pin of the electric energy metering chip U10 is connected with the voltage acquisition circuit, the 2 pin and the 3 pin of the electric energy metering chip U10 are connected with the current acquisition circuit, the 9 pin of the electric energy metering chip U10 is connected with the 30 pin of the MCU control chip U1, the 10 pin of the electric energy metering chip U10 is connected with the 31 pin of the MCU control chip U1, one end of a resistor R136 is connected with the 6 pin of the electric energy metering chip U10, and the other end of the resistor R136 is connected with one end of a resistor R137 and the 32 pin of the MCU control chip U1 respectively, and the other end of the resistor R137 is grounded.

[0019] Further, the AC voltage reduction module comprises a 5V power adapter U7 and a voltage stabilizer U11, the model number of the 5V power adapter U7 is 220V-05B, the model number of the voltage stabilizer U11 is AMS1117-3.3, the 1st pin of the power adapter U7 is connected with a 220V live wire, the 2nd pin of the power adapter U7 is connected with a 220V zero line, the 3rd pin and the 4th pin of the power adapter U7 are connected with the 3rd pin of the voltage stabilizer U11, and the 2nd pin and the 4th pin of the voltage stabilizer U11 are connected with an AC VCC_3V3 voltage terminal.

[0020] Further, the battery charging management module comprises a battery charging management chip U12, the model number of the battery charging management chip U12 is TP5100, a voltage input terminal of the battery charging management chip U12 is connected with a VCC voltage terminal, and the LX terminal of the battery charging management chip U12 is connected with a voltage input terminal of a battery pack and an emergency power disconnecting module and the 10th pin of an MCU control chip U1.

[0021] Further, the voltage detection module comprises a triode Q12, the base of the triode Q12 is connected with one end of a resistor R123 and one end of a resistor R124, the other end of the resistor R123 is connected with a VCC voltage terminal, the emitter of the triode Q12 is connected with the other end of the resistor R124 and then grounded, and the collector of the triode Q12 is connected with one end of a resistor R13 and the 33rd pin of the MCU control chip U1.

[0022] Further, the 4G network module comprises a 4G antenna, a 4G communication chip U20 and an eSIM patch card U21, and the model number of the 4G communication chip U20 is EC800K-CN.

[0023] The 4G antenna and the eSIM patch card U21 are electrically connected with the 4G communication chip U20, and the 4G communication chip U20 is electrically connected with the 21st pin and the 22nd pin of the MCU control chip U1.

[0024] Advantages of the utility model:

[0025] (1) The 4G front-end mains power supply monitoring and control device can realize real-time acquisition of the voltage and current of mains power and upload of the data to a main control module for processing, remote uploading of data by a 4G network module, real-time monitoring of the running state of mains power by a big data analysis platform, and data support for fault analysis and prediction.

[0026] (2) The utility model provides a kind of 4G front-end commercial power supply monitoring and control device, and main control module is combined with emergency power disconnecting module by real-time monitoring power supply state, can quickly respond to commercial power supply failure, automatically switch to standby battery power supply or realize fault recovery through automatic reclosing function, reduce power-off time, battery charging management module ensures that standby battery keeps optimum charging state under non-fault state, provides reliable power support in emergency situation;

[0027] (3) The utility model provides a kind of 4G front-end commercial power supply monitoring and control device, combined with 4G communication module and offline data storage module, device can realize real-time transmission and local backup of data, guarantee the integrity of data, system can be linked with cloud big data analysis platform, utilize intelligent algorithm to carry out fault prediction and analysis, optimize power supply management, improve the intelligent degree of system. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained according to these drawings without creative labor for ordinary skilled in the art.

[0029] Figure 1 System module block diagram of the 4G front-end commercial power supply monitoring and control device proposed by the utility model;

[0030] Figure 2 MCU control chip circuit principle diagram of the 4G front-end commercial power supply monitoring and control device proposed by the utility model;

[0031] Figure 3 System power module circuit principle diagram of the 4G front-end commercial power supply monitoring and control device proposed by the utility model;

[0032] Figure 4 Voltage and current detection module circuit principle diagram of the 4G front-end commercial power supply monitoring and control device proposed by the utility model;

[0033] Figure 5 AC voltage reduction module circuit principle diagram of the 4G front-end commercial power supply monitoring and control device proposed by the utility model;

[0034] Figure 6 Battery charging management module principle diagram of the 4G front-end commercial power supply monitoring and control device proposed by the utility model;

[0035] Figure 7The utility model provides a kind of 4G front end voltage detection module circuit schematic of commercial power supply monitoring and control device of power supply;

[0036] Figure 8 The utility model provides a kind of 4G front end emergency power disconnect module circuit schematic of commercial power supply monitoring and control device of power supply;

[0037] Figure 9 The utility model provides a kind of 4G front end offline data storage module circuit schematic of commercial power supply monitoring and control device of power supply;

[0038] Figure 10 The utility model provides a kind of 4G front end system clock module circuit schematic of commercial power supply monitoring and control device of power supply;

[0039] Figure 11 The utility model provides a kind of 4G front end 4G online module circuit schematic of commercial power supply monitoring and control device Figure 1 ;

[0040] Figure 12 The utility model provides a kind of 4G front end 4G online module circuit schematic of commercial power supply monitoring and control device Figure 2 ;

[0041] Figure 13 The utility model provides a kind of 4G front end 4G online module circuit schematic of commercial power supply monitoring and control device Figure 3 ;

[0042] Figure 14 The utility model provides a kind of 4G front end 4G online module circuit schematic of commercial power supply monitoring and control device Figure 4 ;

[0043] Figure 15 The utility model provides a kind of 4G front end 4G online module circuit schematic of commercial power supply monitoring and control device Figure 5 . Specific implementation

[0044] To make the purpose, technical scheme and advantage of the utility model more clear and obvious, below combining with example and drawing, the utility model is further detailed, the utility model illustrative implementation and its explanation are only used to explain the utility model, and not as the limitation of the utility model.

[0045] Example 1

[0046] Reference Figures 1-15The utility model relates to a kind of 4G front end mains power supply monitoring and control device, including main control module, system power module, voltage and current detection module, AC voltage reduction module, battery charging management module, voltage detection module and 4G online module;

[0047] The main control module is electrically connected with the 4G online module, the battery charging management module, the voltage detection module and the voltage and current detection module respectively;The input end of the system power module is electrically connected with the 220V voltage input end, and the output end of the system power module is electrically connected with the input end of the battery charging management module and the input end of the voltage detection module respectively.

[0048] The input end of the voltage and current detection module is electrically connected with the 220V voltage input end.

[0049] The input end of the AC voltage reduction module is electrically connected with the 220V voltage input end, and the output end of the AC voltage reduction module is connected with the voltage input end of the voltage and current detection module;The 4G online module is electrically connected with the main control module.

[0050] The embodiment also includes an emergency power disconnecting module, which is electrically connected with the main control module.

[0051] The embodiment also includes an offline data storage module and a system clock module, which are electrically connected with the main control module.

[0052] Specifically,

[0053] The main control module includes an MCU control chip U1, and the model of the MCU control chip U1 is STM32F103CBT6.

[0054] The system power module includes a 12V power adapter U4, the model of the 12V power adapter U4 is 220V-12B, the 1 pin of the 12V power adapter U4 is connected with a 220V live wire, the 2 pin of the 12V power adapter U4 is connected with a 220V neutral wire, the 4 pin of the 12V power adapter U4 is connected with one end of a fuse F1, and the other end of the fuse F1 is connected with a VCC voltage end.

[0055] The voltage and current detection module includes a voltage acquisition circuit, a current acquisition circuit and an electric energy metering chip U10, the model of the electric energy metering chip U10 is BL0942, the voltage acquisition circuit includes a resistor R25, one end of the resistor R25 is connected with the AC voltage reduction module, the other end of the resistor R25 is connected with one end of a resistor R23, the other end of the resistor R23 is connected with one end of a capacitor C39, and the other end of the capacitor C39 is connected with the 4 pin of the electric energy metering chip U10.

[0056] The current acquisition circuit includes a current sampling point J5, the 1 pin of the current sampling point J5 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with one end of a capacitor C37 and the 3 pin of an electric energy metering chip U10 respectively, the other end of the capacitor C37 is connected with one end of a capacitor C38 and then grounded, the other end of the capacitor C38 is connected with one end of a resistor R18 and the 2 pin of the electric energy metering chip U10 respectively, the other end of the resistor R18 is connected with the 2 pin of the current sampling point J5, the 9 pin of the electric energy metering chip U10 is connected with the 30 pin of an MCU control chip U1, the 10 pin of the electric energy metering chip U10 is connected with the 31 pin of the MCU control chip U1, the 6 pin of the electric energy metering chip U10 is connected with one end of a resistor R136, the other end of the resistor R136 is connected with one end of a resistor R137 and the 32 pin of the MCU control chip U1 respectively, and the other end of the resistor R137 is grounded.

[0057] The AC voltage reduction module includes a 5V power adapter U7 and a voltage stabilizer U11, the model number of the 5V power adapter U7 is 220V-05B, the model number of the voltage stabilizer U11 is AMS1117-3.3, the 1 pin of the power adapter U7 is connected with one end of a capacitor C1, one end of a voltage-dependent resistor R20, one end of a resistor R25 and one end of a fuse F2 respectively, the other end of the fuse F2 is connected with a 220V live wire, the other end of the voltage-dependent resistor R20 is connected with a 220V neutral wire, the other end of the capacitor C1 and the 2 pin of the power adapter U7 respectively, the 3 pin of the power adapter U7 is connected with one end of a capacitor C44 and then grounded, the other end of the capacitor C44 is connected with the 4 pin of the power adapter U7 and the 3 pin of the voltage stabilizer U11 respectively, and the 2 pin and the 4 pin of the voltage stabilizer U11 are connected with an AC VCC_3V3 voltage end.

[0058] The battery charging management module includes a battery charging management chip U12, the model of the battery charging management chip U12 is TP5100, the 1, 4, 5, 16 pins of the battery charging management chip U12 are connected with one end of a capacitor C16, one end of a capacitor C15, one end of a capacitor C13, one end of a capacitor C22 and a VCC voltage end, the 15 pin of the battery charging management chip U12 is connected with the cathode of a red light emitting diode D1, the anode of the red light emitting diode D1 is connected with one end of a resistor R8 and the anode of a green light emitting diode D3, the other end of the resistor R8 is connected with the VCC voltage end, the cathode of the green light emitting diode D3 is connected with the 14 pin of the battery charging management chip U12, the 2, 3 pins of the battery charging management chip U12 are connected with one end of an inductor L1, the cathode of a Schottky diode D2, the 8 pin of the battery charging management chip U12, one end of a capacitor C26, one end of a capacitor C28, the other end of the inductor L1 and one end of a resistor R5, the other end of the resistor R5 is connected with one end of a capacitor C30, one end of a capacitor C29, the 9 pin of the battery charging management chip U12, the positive pole of a battery pack BT1, one end of a capacitor C17, one end of a capacitor C23, one end of a resistor R19 and an emergency power-off module, the other end of the capacitor C29 is connected with the other end of the capacitor C30, the other end of the capacitor C28, the other end of the capacitor C26, the anode of the Schottky diode, the negative pole of the battery pack BT1, one end of a thermistor R12, one end of a resistor R16, the other end of the capacitor C17, the other end of the capacitor C23 and ground, the other end of the resistor R16 is connected with the 11 pin of the battery charging management chip U12, one end of a resistor R24 and the other end of the thermistor R12, the other end of the resistor R24 is connected with the 10 pin of the battery charging management chip U12, the other end of the resistor R19 is connected with one end of a resistor R27, one end of a capacitor C32 and the 10 pin of an MCU control chip U1.

[0059] The voltage detection module includes a transistor Q12, the base of the transistor Q12 is connected with one end of a resistor R123 and one end of a resistor R124, the other end of the resistor R123 is connected with a VCC voltage end, the emitter of the transistor Q12 is connected with the other end of the resistor R124 and ground, the collector of the transistor Q12 is connected with one end of a resistor R13 and the 33 pin of the MCU control chip U1.

[0060] The emergency power-off module comprises a relay drive chip U6 and a relay P4, the model of the relay drive chip U6 is MD7620A, the 1 pin of the relay P4 is connected with the 1 pin of the relay drive chip U6, the 2 pin of the relay P4 is connected with the 4 pin of the relay drive chip U6, the 5 pin of the relay drive chip U6 is connected with one end of the capacitor C41 and the other end of the resistor R5 respectively, the 6 pin of the relay drive chip U6 is connected with one end of the resistor R21, the other end of the resistor R21 is connected with the 18 pin of the MCU control chip U1, the 3 pin of the relay drive chip U6 is connected with one end of the resistor R17, and the other end of the resistor R17 is connected with the 19 pin of the MCU control chip U1.

[0061] The 4G network module comprises a 4G antenna, a 4G communication chip U20 and an eSIM patch card U21, and the model of the 4G communication chip U20 is EC800K-CN.

[0062] The 4G antenna and the eSIM patch card U21 are respectively connected with the 4G communication chip U20, and the 4G communication chip U20 is connected with the 21 pin and the 22 pin of the MCU control chip U1.

[0063] After the device is started, the system power module is connected with 220V mains, converts alternating current into direct current, and provides stable working power supply for the main control module, the voltage detection module, the voltage and current detection module, the battery charging management module and other functional modules. At the same time, the voltage and current detection module collects mains voltage and current in real time through the voltage acquisition circuit, the current acquisition circuit and the electric energy metering chip BL0942, and analyzes and processes the collected data through the STM32F103CBT6 chip in the main control module; in addition, the voltage detection module realizes auxiliary detection of mains voltage through the transistor Q12 and related circuits, further improving the detection accuracy.

[0064] In the running process, the main control module comprehensively analyzes the data fed back by the voltage and current detection module and the voltage detection module, realizes remote uploading of data through the 4G communication module EC800K-CN, the 4G communication module is connected with the external network through the 4G antenna, and data encryption transmission is realized by using the eSIM card, and the collected mains running state information is uploaded to the cloud big data analysis platform. The cloud platform can analyze and predict the data through intelligent algorithms, and provide optimization scheme for power supply management.

[0065] Meanwhile, the device combines the emergency power-off module for fault response. When the main control module detects that the mains power supply is abnormal or power failure, it quickly switches to the backup battery power supply mode through the relay drive chip MD7620A and the relay P4, ensuring the continuous operation of critical equipment. The battery charging management module based on the intelligent charging control function of the TP5100 chip monitors the status of the backup battery in real time and manages the charging of the battery under non-fault conditions, ensuring that the backup battery is always in the best state.

[0066] In addition, the device supports local storage and backup of data. The offline data storage module is connected with the main control module, which can save key data in the local storage under network anomalies or other special circumstances, ensuring the integrity of the data. The system clock module provides accurate time reference to support data recording and event analysis. After the normal power supply is restored, the main control module can restore the mains power supply through the automatic reclosing function and upload the offline stored data to the cloud platform, realizing the overall synchronization and update of the data.

[0067] During the operation of the entire device, the modules cooperate with each other through circuits and logic control to ensure the stability and reliability of the power supply system. With the help of 4G communication and cloud big data platform, the device can monitor, analyze and optimize power supply management in real time, providing support for the construction of intelligent power system.

[0068] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. The skilled person in the art should understand that the utility model is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the utility model, and various changes and improvements can be made to the utility model without departing from the spirit and scope of the utility model. These changes and improvements all fall within the scope of the claimed utility model. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A 4G front-end AC power supply monitoring and control device, characterized in that, The system power module, the voltage and current detection module, the AC voltage reduction module, the battery charging management module, the voltage detection module and the 4G network module are connected with the main control module. The main control module is connected with the 4G network module, the battery charging management module, the voltage detection module and the voltage and current detection module. The input end of the system power module is connected with the 220V voltage input end, and the output end of the system power module is connected with the input end of the battery charging management module and the input end of the voltage detection module. The input end of the voltage and current detection module is connected with the 220V voltage input end. The input end of the AC voltage reduction module is connected with the 220V voltage input end, and the output end of the AC voltage reduction module is connected with the voltage input end of the voltage and current detection module. The 4G network module is connected with the main control module.

2. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The emergency power disconnect module is connected with the main control module.

3. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The offline data storage module and the system clock module are connected with the main control module.

4. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The main control module comprises an MCU control chip U1, and the model of the MCU control chip U1 is STM32F103CBT6.

5. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The system power module comprises a 12V power adapter U4, the model of the 12V power adapter U1 is 220V-12B, the 1st pin of the 12V power adapter U4 is connected with the 220V live wire, the 2nd pin of the 12V power adapter U4 is connected with the 220V neutral wire, the 4th pin of the 12V power adapter U4 is connected with one end of a fuse F1, and the other end of the fuse F1 is connected with a VCC voltage end.

6. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The voltage and current detection module comprises a voltage acquisition circuit, a current acquisition circuit and an electric energy metering chip U10, the model of the electric energy metering chip U10 is BL0942, the voltage acquisition circuit is connected with the 4th pin of the electric energy metering chip U10, the current acquisition circuit is connected with the 2nd pin and the 3rd pin of the electric energy metering chip U10, the 9th pin of the electric energy metering chip U10 is connected with the 30th pin of the MCU control chip U1, the 10th pin of the electric energy metering chip U10 is connected with the 31st pin of the MCU control chip U1, the 6th pin of the electric energy metering chip U10 is connected with one end of a resistor R136, and the other end of the resistor R136 is connected with one end of a resistor R137 and the 32nd pin of the MCU control chip U1, and the other end of the resistor R137 is grounded.

7. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The AC voltage reduction module comprises a 5V power adapter U7 and a voltage stabilizer U11, the model of the 5V power adapter U7 is 220V-05B, the model of the voltage stabilizer U11 is AMS1117-3.3, the 1st pin of the power adapter U7 is connected with the 220V live wire, the 2nd pin of the power adapter U7 is connected with the 220V neutral wire, the 3rd pin and the 4th pin of the power adapter U7 are connected with the 3rd pin of the voltage stabilizer U11, and the 2nd pin and the 4th pin of the voltage stabilizer U11 are connected with an AC VCC_3V3 voltage end.

8. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The battery charging management module comprises a battery charging management chip U12, the model of the battery charging management chip U12 is TP5100, the voltage input end of the battery charging management chip U12 is connected with the VCC voltage end, and the LX end of the battery charging management chip U12 is connected with the voltage input end of the battery pack and the emergency power-off module and the 10th pin of the MCU control chip U1 respectively.

9. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The voltage detection module comprises a triode Q12, the base of the triode Q12 is connected with one end of a resistor R123 and one end of a resistor R124, the other end of the resistor R123 is connected with the VCC voltage end, the emitter of the triode Q12 is connected with the other end of the resistor R124 and then grounded, and the collector of the triode Q12 is connected with one end of a resistor R13 and the 33th pin of the MCU control chip U1 respectively.

10. A 4G front-end AC power supply monitoring and control device according to claim 1, characterized in that, The 4G network module comprises a 4G antenna, a 4G communication chip U20 and an eSIM patch card U21, the model of the 4G communication chip U20 is EC800K-CN, the 4G antenna and the eSIM patch card U21 are electrically connected with the 4G communication chip U20 respectively, and the 4G communication chip U20 is electrically connected with the 21st pin and the 22nd pin of the MCU control chip U1.

Images