CN216485240U

CN216485240U - Multifunctional monitoring device

Info

Publication number: CN216485240U
Application number: CN202122149386.0U
Authority: CN
Inventors: 乔兴波; 陈孔亮
Original assignee: Shenzhen Sinway South Technology Co ltd
Current assignee: Shenzhen Sinway South Technology Co ltd
Priority date: 2021-09-07
Filing date: 2021-09-07
Publication date: 2022-05-10
Anticipated expiration: 2031-09-07

Abstract

The utility model relates to the technical field of monitors, and provides a multifunctional monitoring device which comprises a temperature and humidity sensor, a power supply circuit, an electric energy metering chip, a photoelectric communication circuit, an anti-static communication circuit and a main control chip, wherein the electric energy metering chip, the photoelectric communication circuit, the anti-static communication circuit and the main control chip are respectively and electrically connected with the power supply circuit, the main control chip is respectively and electrically connected with the temperature and humidity sensor through the anti-static communication circuit, the electric energy metering chip, the photoelectric communication circuit, the anti-static communication circuit and the main control chip are powered through the power supply circuit, the power supply efficiency of the power supply circuit is improved, the main control chip and the temperature and humidity sensor are communicated through the anti-static communication circuit to monitor temperature and humidity, the main control chip and the electric energy metering chip are communicated through the photoelectric communication circuit to monitor electric energy, and the monitoring performance of the multifunctional monitoring device is improved.

Description

Multifunctional monitoring device

Technical Field

The utility model relates to the technical field of monitors, in particular to a multifunctional monitoring device.

Background

At present, in a plurality of scenes such as industrial production, smart home and the like, a monitoring device such as a smart electric meter is needed to monitor electric energy, so that guarantee is provided for electric safety, and maintenance and inspection work of electricians is reduced.

However, in some cases, the monitoring device itself may be affected by the environment and malfunction, for example, the smart meter may have a large electric energy monitoring error in a production workshop due to an excessively high temperature of the environment, or the smart meter may burn out outdoors due to infiltration of rain in a rainfall environment, and therefore, it is particularly important for the monitoring device to monitor the temperature and humidity of the environment where the monitoring device is located.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problems in the related technology at least to a certain extent, and provides a multifunctional monitoring device which comprises a temperature and humidity sensor, a power supply circuit, an electric energy metering chip, a photoelectric communication circuit, an anti-static communication circuit and a main control chip, wherein the electric energy metering chip, the photoelectric communication circuit, the anti-static communication circuit and the main control chip are respectively electrically connected with the temperature and humidity sensor through the anti-static communication circuit and the electric energy metering chip through the photoelectric communication circuit.

Optionally, the power supply circuit includes a buck-type isolated power supply sub-circuit, a first buck-type voltage-stabilizing sub-circuit, an isolated-to-non-isolated power supply sub-circuit, and a second buck-type voltage-stabilizing sub-circuit, a first voltage output end of the buck-type isolated power supply sub-circuit is electrically connected to a first voltage input end of the first buck-type voltage-stabilizing sub-circuit and a second voltage input end of the second buck-type voltage-stabilizing sub-circuit, respectively, and a second voltage output end of the first buck-type voltage-stabilizing sub-circuit is electrically connected to a third voltage input end of the isolated-to-non-isolated power supply sub-circuit;

and a third voltage output end of the isolation-to-non-isolation power supply sub-circuit is electrically connected with a power supply pin of the electric energy metering chip and a fourth voltage input end of the photoelectric communication circuit respectively, and a fourth voltage output end of the second buck-type voltage-stabilizing sub-circuit is electrically connected with a fifth voltage input end of the photoelectric communication circuit, a sixth voltage input end of the anti-static communication circuit and a power supply pin of the main control chip respectively.

Optionally, the first buck regulator sub-circuit includes a three-terminal regulator tube and a first filter capacitor, an input end of the three-terminal regulator tube is set as the first voltage input end, an output end of the three-terminal regulator tube is set as the second voltage output end through the first filter capacitor, and a ground end of the three-terminal regulator tube is grounded;

the isolated non-isolated power supply sub-circuit comprises an isolated DC-DC converter, a second filter capacitor, a third filter capacitor and a first filter resistor connected with the third filter capacitor in parallel, wherein the input end of the isolated DC-DC converter is set as the third voltage input end which is grounded through the second filter capacitor, one grounding end of the isolated DC-DC converter is grounded to form an isolated voltage input loop with the third voltage input end, the output end of the isolated DC-DC converter is set as the third voltage output end which is connected with zero through the first filter resistor, and the other grounding end of the isolated DC-DC converter is connected with zero to form a non-isolated voltage output loop with the third voltage output end.

Optionally, the second buck-type voltage regulator sub-circuit includes a buck-type voltage regulator chip, a fourth filter capacitor, a freewheeling diode, an inductor, a fifth filter capacitor, a first buck resistor, a second buck resistor, and a shunt resistor, an input end of the buck-type voltage regulator chip is set as the second voltage input end grounded through the fourth filter capacitor, an output end of the buck-type voltage regulator chip is electrically connected to a cathode of the freewheeling diode and the fifth filter capacitor through the inductor, respectively, a ground end of the buck-type voltage regulator chip is grounded to the fourth filter capacitor, an anode of the freewheeling diode, and the fifth filter capacitor, one end of the first buck resistor is electrically connected to a common terminal between the inductor and the fifth filter capacitor, and the other end of the first buck resistor is electrically connected to a feedback terminal of the buck-type voltage regulator chip and one end of the second buck resistor, respectively, and one end of the shunt resistor is electrically connected with one end of the first step-down resistor, and then the common end is set as the fourth voltage output end, and the other end of the shunt resistor is electrically connected with the other end of the second step-down resistor.

Optionally, the number of the circuits of the optoelectronic communication circuit is multiple, each of the circuits of the optoelectronic communication circuit includes an optical coupler, a first pull-up resistor, a second pull-up resistor, and a sixth filter capacitor, an anode of the optical coupler is electrically connected to one end of the first pull-up resistor, a collector of the optical coupler is electrically connected to one end of the second pull-up resistor and one end of the sixth filter capacitor, respectively, and an emitter of the optical coupler is grounded to the other end of the sixth filter capacitor;

in one path of the optoelectronic communication circuit, the other end of the first pull-up resistor is set as the fourth voltage input end, the other end of the second pull-up resistor is set as the fifth voltage input end, a cathode of the optical coupler is electrically connected with a first data sending pin of the electric energy metering chip, and a collector of the optical coupler is also electrically connected with a second data receiving pin of the main control chip;

in another way among the photoelectric communication circuit, the other end of first pull-up resistance establishes to fifth voltage input end, the other end of second pull-up resistance establishes to fourth voltage input end, the negative pole of optical coupler with main control chip's second data transmission pin electricity is connected, optical coupler's collecting electrode still with electric energy metering chip's first data receiving pin electricity is connected.

Optionally, the multifunctional monitoring device further comprises a USB communication circuit, an acoustic alarm circuit, an ethernet communication circuit, a display circuit and a key circuit, wherein the USB communication circuit and the acoustic alarm circuit are electrically connected between the second voltage output terminal and the main control chip respectively, and the ethernet communication circuit, the display circuit and the key circuit are electrically connected between the fourth voltage output terminal and the main control chip respectively.

Optionally, the multifunctional monitoring device further includes an RJ45 interface circuit, an auxiliary control chip and a plurality of differential communication circuits, the fourth voltage output terminal is respectively connected with each path of the seventh voltage input terminal of the differential communication circuit and the power pin of the auxiliary control chip, a pair of differential signal transmission pins of the main control chip are connected with the third data receiving pin and the third data sending pin of the auxiliary control chip through one path, the fourth data receiving pin and the fourth data sending pin of the main control chip are connected with another path of the differential communication circuit respectively and the pair of differential signal transmission terminals of the RJ45 interface circuit are electrically connected.

Optionally, the at least one path of differential communication circuit includes an RS485 communication chip, a third pull-up resistor, a fourth pull-up resistor, a power supply bypass capacitor, a bidirectional voltage regulator diode, a pull-down resistor, an NPN-type triode, a first light-emitting sub-circuit, a fifth pull-up resistor, a second light-emitting sub-circuit, a first current-limiting resistor, and a second current-limiting resistor;

a power supply pin of the RS485 communication chip, one end of the third pull-up resistor and one end of the fourth pull-up resistor are respectively set as the seventh voltage input end, the sixth voltage input end of the RS485 communication chip is grounded through the power supply bypass capacitor, the in-phase pin of the RS485 communication chip is respectively and electrically connected with the other end of the third pull-up resistor and one end of the bidirectional voltage stabilizing diode, the reverse-phase pin of the RS485 communication chip is respectively electrically connected with the other end of the bidirectional voltage stabilizing diode and grounded through the pull-down resistor, the receiver output pin of the RS485 communication chip is electrically connected with the other end of the fourth pull-up resistor, the receiving enabling pin and the sending enabling pin of the RS485 communication chip are both electrically connected with the collector electrode of the NPN type triode, the grounding pin of the RS485 communication chip, the input pin of the driver and the emitter of the NPN type triode are grounded together;

the first light-emitting sub-circuit is electrically connected between two ends of the fourth pull-up resistor, the seventh voltage input end of the fourth pull-up resistor is electrically connected with the collector of the NPN type triode through the fifth pull-up resistor, the seventh voltage input end of the fourth pull-up resistor is electrically connected with the base of the NPN type triode sequentially through the first current-limiting resistor and the second current-limiting resistor, and the second light-emitting sub-circuit is electrically connected between the seventh voltage input end of the fourth pull-up resistor and the second current-limiting resistor;

the pair of differential signal transmission pins of the main control chip are respectively and electrically connected with the anti-phase pin and the in-phase pin of the RS485 communication chip, the third data receiving pin is electrically connected with the receiver output pin of the RS485 communication chip, and the third data sending pin is electrically connected with the base electrode of the NPN type triode through the second current limiting resistor.

Optionally, the multifunctional monitoring device further includes a first voltage sampling circuit, a second voltage sampling circuit and a current sampling circuit, the first voltage sampling circuit includes a lightning protection sub-circuit, a voltage divider sub-circuit and a filter sub-circuit, a voltage output end of the lightning protection sub-circuit passes through the voltage divider sub-circuit with a voltage input end of the filter sub-circuit and a voltage positive input pin of the electric energy metering chip are electrically connected, a voltage input end of the second voltage sampling circuit is electrically connected with a voltage negative input pin of the electric energy metering chip, a pair of current output ends of the current sampling circuit is electrically connected with a pair of current input pins of the electric energy metering chip.

Optionally, the lightning protection sub-circuit comprises a connection terminal and a piezoresistor, a live wire end of the connection terminal is electrically connected with one end of the piezoresistor and a voltage input end of the voltage divider sub-circuit respectively, and a null wire end of the connection terminal is grounded with the other end of the piezoresistor.

The multifunctional monitoring device has the beneficial effects that: the power supply circuit supplies power to the electric energy metering chip, the photoelectric communication circuit, the anti-static communication circuit and the main control chip, the power supply efficiency of the power supply circuit is improved, the communication is provided for the main control chip and the temperature and humidity sensor through the anti-static communication circuit so as to monitor the temperature and humidity, the communication is provided for the main control chip and the electric energy metering chip through the photoelectric communication circuit so as to monitor the electric energy, and the monitoring performance of the multifunctional monitoring device is improved.

Drawings

Fig. 1 is a schematic circuit diagram of a multifunctional monitoring device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a buck isolated power supply sub-circuit according to an embodiment of the present invention;

FIG. 3 is a diagram of a first buck regulator sub-circuit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an isolated to non-isolated power supply sub-circuit according to an embodiment of the present invention;

FIG. 5 is a diagram of a second buck regulator sub-circuit according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an electric energy metering chip and its peripheral circuits according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of an optoelectronic communication circuit according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of another optical-electrical communication circuit according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of an anti-electrostatic communication circuit according to an embodiment of the utility model;

fig. 10 is a schematic diagram of an RJ45 interface circuit according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of a differential communication circuit according to an embodiment of the present invention;

FIG. 12 is a diagram of an auxiliary control chip and its peripheral circuits according to an embodiment of the present invention;

FIG. 13 is a diagram of a first voltage sampling circuit according to an embodiment of the present invention;

FIG. 14 is a diagram of a second voltage sampling circuit according to an embodiment of the present invention;

FIG. 15 is a schematic diagram of a current sampling circuit according to an embodiment of the present invention;

fig. 16 is a circuit diagram of a multifunctional monitoring device according to an embodiment of the present invention.

Detailed Description

In order that the above objects, features and advantages of the present invention will become more apparent, embodiments in accordance with the present invention will be described in detail below with reference to the accompanying drawings, wherein like reference numerals refer to the same or similar elements throughout the different views unless otherwise specified.

It is noted that the terms "aspect," "optionally," and "exemplary" described in the present specification mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or the embodiment is included in at least one embodiment or an exemplary embodiment of the present invention, and embodiments described in the following exemplary embodiments do not represent all embodiments of the present invention, and are merely examples of apparatuses and methods consistent with some aspects disclosed in the present invention as detailed in the claims, and the scope of the present invention is not limited thereto, and features in various embodiments of the present invention may be combined with each other without contradiction.

Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the present invention, "a plurality" means at least two, e.g., two or three, etc., unless specifically limited otherwise.

Referring to fig. 1, the multifunctional monitoring device according to an embodiment of the present invention includes a temperature and humidity sensor, a power supply circuit, and an electric energy metering chip, an optoelectronic communication circuit, an anti-static communication circuit, and a main control chip that are electrically connected to the power supply circuit, respectively, where the main control chip is electrically connected to the temperature and humidity sensor through the anti-static communication circuit, and is electrically connected to the electric energy metering chip through the optoelectronic communication circuit.

For example, the electric energy metering chip may adopt a single-phase anti-electricity-stealing metering chip U1 shown in fig. 6, the model of the single-phase anti-electricity-stealing metering chip U1 may be RN8209G, and the main control chip may adopt an MCU chip (not shown in the figure) of the model STM32F429, and it should be understood that both the foregoing chips may be implemented by using the prior art, and will not be described herein again.

For electric energy measurement chip, photoelectric communication circuit, prevent that static communication circuit and main control chip supply power through power supply circuit, promoted power supply efficiency, provide communication for main control chip and temperature and humidity sensor through preventing static communication circuit to monitor the humiture, provide communication for main control chip and electric energy measurement chip through photoelectric communication circuit, with the monitoring electric energy, promoted multi-functional monitoring device's monitoring performance.

Alternatively, referring to fig. 2, 3, 4, 5 and 16, the power supply circuit includes a buck-type isolated power supply sub-circuit, a first buck-type voltage-stabilizing sub-circuit, an isolated-to-non-isolated power supply sub-circuit and a second buck-type voltage-stabilizing sub-circuit, the buck-type isolated power supply sub-circuit is provided with a first voltage output end, the first buck-type voltage-stabilizing sub-circuit is provided with a first voltage input end and a second voltage output end, the second buck-type voltage-stabilizing sub-circuit is provided with a second voltage input end and a fourth voltage output end, the isolated-to-non-isolated power supply sub-circuit is provided with a third voltage input end and a third voltage output end, the optoelectronic communication circuit is provided with a fourth voltage input end and a fifth voltage input end, and the anti-static communication circuit is provided with a sixth voltage input end.

The first voltage output end is electrically connected with the first voltage input end and the second voltage input end respectively, the second voltage output end is electrically connected with the third voltage input end, the third voltage output end is electrically connected with a power pin of the electric energy metering chip and the fourth voltage input end respectively, and the fourth voltage output end is electrically connected with the fifth voltage input end, the sixth voltage input end and a power pin of the main control chip respectively.

For example, the step-down isolated power supply sub-circuit may adopt an isolated AC-DC switching power supply circuit as shown in fig. 2, wherein a full-bridge rectifier bridge may be electrically connected to a live line and a zero line of a mains supply, a 220V AC voltage is directly obtained from the mains supply through the full-bridge rectifier bridge to convert the 220V AC voltage into a 12V DC voltage, two diodes are respectively electrically connected to a secondary winding of a transformer, a common terminal between the two diodes may be set as a first voltage output terminal suitable for outputting the 12V DC voltage, and the step-down isolated power supply sub-circuit uses the ground as a constant zero reference potential.

The first isolation voltage from the voltage-reducing isolation power supply sub-circuit is converted into a second isolation voltage for supplying power to the isolation-to-non-isolation power supply sub-circuit through the first voltage-reducing type voltage-stabilizing sub-circuit, the second isolation voltage is converted into a non-isolation voltage for supplying power to the electric energy metering chip and the photoelectric communication circuit through the isolation-to-non-isolation power supply sub-circuit, the non-isolation power consumption requirements of the electric energy metering chip and the photoelectric communication circuit are met at the same time, the first isolation voltage is converted into a third isolation voltage for supplying power to the photoelectric communication circuit, the differential communication circuit and the main control chip through the second voltage-reducing type voltage-stabilizing sub-circuit, the isolation power consumption requirements of the auxiliary control chip, the photoelectric communication circuit, the anti-static communication circuit and the main control chip are met at the same time, the power supply purpose of the voltage-reducing type isolation power supply sub-circuit is expanded, and the power supply performance is improved.

Optionally, referring to fig. 2, 3 and 16, the first buck regulator sub-circuit includes a three-terminal regulator tube U3 and a first filter capacitor C1, a voltage input terminal Vin of the three-terminal regulator tube U3 is set as a first voltage input terminal, a voltage output terminal Vout of the three-terminal regulator tube U3 is set as a second voltage output terminal that is grounded through the first filter capacitor C1, and a ground terminal GND of the three-terminal regulator tube U3 is grounded.

Illustratively, the model of the three-terminal regulator tube U3 may be 78M05, the 12V dc voltage as the first isolation voltage may be converted into the 5V dc voltage as the second isolation voltage by the three-terminal regulator tube U3, the ground terminal GND of the three-terminal regulator tube U3 may be connected to the ground as the reference potential, and the first filter capacitor C1 filters between the second voltage output terminal of the three-terminal regulator tube U3 and the ground terminal GND, which gives consideration to the reliability and simplicity of the first buck regulator sub-circuit.

Optionally, referring to fig. 3, 4 and 16, the isolated to non-isolated power supply sub-circuit includes an isolated DC-DC converter U4, a second filter capacitor C2, a third filter capacitor C3 and a first filter resistor R1 connected in parallel to the third filter capacitor C3, a voltage input terminal Vin of the isolated DC-DC converter U4 is set as a third voltage input terminal grounded through the second filter capacitor C2, a ground terminal GND1 of the isolated DC-DC converter U4 is grounded to form an isolated voltage input loop with the third voltage input terminal, a voltage output terminal Vout of the isolated DC-DC converter U4 is set as a third voltage output terminal that is connected to zero through the first filter resistor R1, and another ground terminal GND2 of the isolated DC-DC converter is connected to zero to form a non-isolated voltage output loop with the third voltage output terminal.

Illustratively, the isolated DC-DC converter U4 may be H0505S-1WR2, the isolated DC-DC converter U4 may convert the second isolated voltage into a non-isolated voltage, the voltage value of the non-isolated voltage may be 5V, the ground terminal GND1 of the isolated DC-DC converter U4 may be connected to the ground, the other ground terminal GND2 of the isolated DC-DC converter U4 and the power ground AGND of the single-phase anti-theft power metering chip U1 may both be connected to the zero line of the utility power, and the potentials of the two terminals are the same and can fluctuate along with the zero line, which facilitates to convert the isolated DC-DC converter into the non-isolated power supply sub circuit and to improve the power monitoring accuracy.

Illustratively, the two second filter capacitors C2 after being connected in parallel filter between the third voltage input terminal of the isolated DC-DC converter U4 and the ground terminal GND1, the two third filter capacitors C3 after being connected in parallel filter between the third voltage output terminal of the isolated DC-DC converter U4 and the ground terminal GND2, and the first filter resistor R1 is used as a dummy load resistor, which helps to ensure the reliability of the isolated to non-isolated power supply sub-circuit.

Alternatively, referring to fig. 2, 5 and 16, the second buck-type voltage-stabilizing sub-circuit includes a buck-type voltage-stabilizing chip U5, a fourth filter capacitor C4, a freewheeling diode D, an inductor L, a fifth filter capacitor C5, a first buck resistor R2, a second buck resistor R3 and a shunt resistor R4, a voltage input terminal Vin of the buck-type voltage-stabilizing chip U5 is set as a second voltage input terminal grounded through the fourth filter capacitor C4, a voltage output terminal Vout of the buck-type voltage-stabilizing chip U5 is electrically connected to a cathode of the freewheeling diode D and to the fifth filter capacitor C5 through the inductor L, respectively, a ground terminal GND of the buck-type voltage-stabilizing chip U5 is grounded to the fourth filter capacitor C4, an anode of the freewheeling diode D and the fifth filter capacitor C5, one end of the first buck resistor R2 is electrically connected to a common terminal between the inductor L and the fifth filter capacitor C5, and the other end of the first buck resistor R2 is electrically connected to a feedback terminal of the buck feedback resistor FB 5 and the second buck feedback resistor R3, a common end of the shunt resistor R4 electrically connected to one end of the first voltage-reducing resistor R2 is set as a fourth voltage output end, and the other end of the shunt resistor R4 is electrically connected to the other end of the second voltage-reducing resistor R3.

Illustratively, the buck regulator chip U5 may be of a model LM2576SX-ADJ, wherein the control terminal ON/OFF is electrically connected between the ground terminal GND and the anode of the freewheeling diode D, the ground terminal GND of the buck regulator chip U5 is connected to the ground, and the first isolation voltage may be converted into a 3.3V dc voltage as the third isolation voltage by the buck regulator chip U5.

Illustratively, three fifth filter capacitors C5 are connected in parallel to form a capacitor filter circuit, two shunt resistors R4 are connected in parallel, and a common end between any fifth filter capacitor C5 and the inductor L, the first voltage-reducing resistor R2 and any shunt resistor R4 can be set as a fourth voltage output end.

The voltage is filtered between the second voltage input end of the buck-type voltage-stabilizing chip U5 and the ground end GND through the fourth filter capacitor C4, the freewheeling diode D freewheels between the voltage output end Vout of the buck-type voltage-stabilizing chip U5 and the ground end GND, reverse voltage protection caused by voltage mutation caused by the inductor L is eliminated, filtering is performed between the inductor L and the freewheeling diode D through the fifth filter capacitor C5, voltage is reduced through the first buck resistor R2 and the second buck resistor R3, current is limited through the shunt resistor R4, and the reliability of the second buck-type voltage-stabilizing sub-circuit is improved.

Alternatively, referring to fig. 7 and 8, the number of the optical communication circuits is multiple, each optical communication circuit includes an optical coupler OC, a first pull-up resistor R5, a second pull-up resistor R6, and a sixth filter capacitor C6, an anode of the optical coupler OC is electrically connected to one end of the first pull-up resistor R5, a collector of the optical coupler OC is electrically connected to one end of the second pull-up resistor R6 and one end of the sixth filter capacitor C6, respectively, and an emitter of the optical coupler OC is grounded to the other end of the sixth filter capacitor C6, for example, an emitter of the optical coupler OC is connected to ground.

Referring to fig. 6, 7 and 16, in one path of the optoelectronic communication circuit, the other end of the first pull-up resistor R5 is set as a fourth voltage input end, the other end of the second pull-up resistor R6 is set as a fifth voltage input end, the cathode of the optical coupler OC is electrically connected to the first data transmission pin TX of the power metering chip, and the collector of the optical coupler OC is also electrically connected to the second data reception pin RX of the main control chip, for example, the first data transmission pin TX may be a pin SDO on a single-phase anti-theft power metering chip U1 of the model RN8209G, and the second data reception pin RX may be a pin PD6 (not shown in the drawing) on an MCU chip of the model STM32F 429.

Referring to fig. 6, 8 and 16, in another optical-electrical communication circuit, the other end of the first pull-up resistor R5 is set as a fifth voltage input end, the other end of the second pull-up resistor R6 is set as a fourth voltage input end, the cathode of the optical coupler OC is electrically connected to the second data transmission pin TX of the main control chip, and the collector of the optical coupler OC is also electrically connected to the first data reception pin RX of the power metering chip, for example, the second data transmission pin TX may be a pin PD5 (not shown) on the MCU chip of model STM32F429, and the first data reception pin RX may be a pin SDI on the single-phase anti-theft power metering chip U1 of model RN 8209G.

Data are transmitted to the main control chip from the electric energy metering chip through one path of photoelectric communication circuit, and data are transmitted to the electric energy metering chip from the main control chip through the other path of photoelectric communication circuit, so that bidirectional communication is performed between the electric energy metering chip and the main control chip, and the communication performance of the multifunctional monitoring device is improved.

Optionally, referring to fig. 9, the anti-static communication circuit includes a static electricity suppressor U6 and a first RJ45 interface, a power supply pin Vbus of the static electricity suppressor U6 and a power supply pin VSS of the first RJ45 interface are respectively set as sixth voltage input ends, a first input/output pin I01-1 of the static electricity suppressor U6 is electrically connected to a dummy pin NC of the first RJ45 interface, a second input/output pin I01-2 of the static electricity suppressor U6 is left empty, a third input/output pin I02-1 of the static electricity suppressor U6 is electrically connected to a bidirectional data transmission pin SDA of the first RJ45 interface, a fourth input/output pin I02-2 of the static electricity suppressor U6 is electrically connected to an input/output pin of the main control chip, and a ground pin GND of the static electricity suppressor U6 and a ground pin EGND of the first RJ45 interface are respectively grounded, thereby ensuring reliability of the circuit.

Illustratively, the fourth input/output pin I02-2 is electrically connected to the input/output pin PB6 on the MCU chip of model STM32F429 through a current-limiting resistor, the ground pin GND of the electrostatic suppressor U6 may be connected to the ground, the ground pin EGND of the first RJ45 interface may be grounded for lightning protection, and the temperature and humidity sensor is connected to the first RJ45 interface in a hot-plug manner.

Optionally, referring to fig. 10, 11, 12, and 16, the multifunctional monitoring device further includes an RJ45 interface circuit, an auxiliary control chip, and multiple differential communication circuits, where a fourth voltage output terminal is electrically connected to a seventh voltage input terminal of each differential communication circuit and a power pin of the auxiliary control chip, a pair of differential signal transmission pins of the main control chip is electrically connected to a third data receiving pin and a third data transmitting pin of the auxiliary control chip through one differential communication circuit, and a fourth data receiving pin and a fourth data transmitting pin of the main control chip are electrically connected to a pair of differential signal transmission terminals of the RJ45 interface circuit through another differential communication circuit.

Illustratively, the RJ45 interface circuit includes a thermistor PTC, a bidirectional zener diode TVS1 and two second RJ45 interfaces, one end of the thermistor PTC is electrically connected to a common terminal between inverting pins 485B of the two second RJ45 interfaces, the other end of the thermistor PTC is set to an inverting terminal 485B, a common terminal between inverting pins 485A of the two second RJ45 interfaces is a non-inverting terminal 485A, the bidirectional zener diode TVS1 is electrically connected between the inverting terminal 485B and the non-inverting terminal 485A, the inverting terminal 485B and the non-inverting terminal 485A form a pair of differential signal terminals of the RJ45 interface circuit, the fourth data receiving pin RX may employ a pin PC7 on an MCU chip having a model of STM32F429, and the fourth data transmitting pin TX may employ a pin PC6 on an MCU chip having a model of STM32F 429.

The power supply circuit supplies power to the auxiliary control chip and the multi-path differential communication circuit, the main control chip and the auxiliary control chip are communicated through one path of differential communication circuit, the main control chip and the RJ45 interface circuit are communicated through the other path of differential communication circuit, a communication channel is expanded, the auxiliary chip and the electric energy metering chip are supported to share control pressure for the main control chip respectively, and the power supply performance, the communication performance and the monitoring performance of the power supply monitoring device are improved.

Optionally, referring to fig. 11, each differential communication circuit includes an RS485 communication chip U7, a third pull-up resistor R7, a fourth pull-up resistor R8, a power bypass capacitor C7, a bidirectional zener diode TVS2, a pull-down resistor R9, an NPN-type transistor Q, a first light emitting sub-circuit, a fifth pull-up resistor R10, a second light emitting sub-circuit, a first current limiting resistor R11, and a second current limiting resistor R12.

A power supply pin VCC of the RS485 communication chip U7, one end of a third pull-up resistor R7 and one end of a fourth pull-up resistor R8 are respectively set as a seventh voltage input end, a sixth voltage input end of the RS485 communication chip U7 is grounded through a power bypass capacitor C7, an in-phase pin A of the RS485 communication chip U7 is respectively and electrically connected with the other end of the third pull-up resistor R7 and one end of a bidirectional zener diode TVS2, an anti-phase pin B of the RS485 communication chip is respectively and electrically connected with the other end of the bidirectional zener diode TVS2 and grounded through a pull-down resistor R9, a receiver output pin RO of the RS485 communication chip U7 is electrically connected with the other end of the fourth pull-up resistor R8, a receive enable pin RE and a transmit enable pin DE of the RS485 communication chip U7 are both electrically connected with a collector of the NPN type triode Q, a ground pin of the RS485 communication chip U7, an input pin DI of the NPN driver and an emitter of the NPN type triode Q are commonly grounded, the pull-down resistor R9 may be a first pull-down resistor.

The first light-emitting sub-circuit is electrically connected between two ends of a fourth pull-up resistor R8, a seventh voltage input end of the fourth pull-up resistor R8 is electrically connected with a collector of the NPN type triode Q through a fifth pull-up resistor R10, a seventh voltage input end of the fourth pull-up resistor R8 is electrically connected with a base of the NPN type triode Q through a first current-limiting resistor R11 and a second current-limiting resistor R12 in sequence, the second light-emitting sub-circuit is electrically connected between the seventh voltage input end of the fourth pull-up resistor R8 and a second current-limiting resistor R12, and an emitter of the NPN type triode Q is connected with the ground.

Illustratively, the first light emitting sub-circuit may be formed by a light emitting diode LED and a third current limiting resistor R13 connected in series, wherein an anode of the light emitting diode LED is electrically connected to the sixth voltage input terminal of the fourth pull-up resistor R8, and a cathode of the light emitting diode LED is electrically connected to a common terminal between the first current limiting resistor R11 and the second current limiting resistor R12 through the third current limiting resistor R13, and it is understood that the second light emitting sub-circuit is similar to the first light emitting sub-circuit and is not described herein again.

Referring to fig. 11, 12 and 16, a pair of differential signal transmission pins of the main control chip are electrically connected to an inverting pin B and an non-inverting pin a of the RS485 communication chip U7, respectively, the third data receiving pin RX is electrically connected to a receiver output pin RO of the RS485 communication chip U7, and the third data transmitting pin TX is electrically connected to a base of the NPN type triode through a second current limiting resistor R12.

Illustratively, a pin PC10 and a pin PC11 (not shown in the figure) on the MCU chip of model STM32F429 may constitute a first pair of differential signal transmission pins, the auxiliary control chip may employ an embedded MCU chip U2 as shown in fig. 10, the embedded MCU chip U2 may be of model STM32F103C8T6, the pin PA10 of the embedded MCU chip U2 may be set as a third data receiving pin RX, and the pin PA9 of the embedded MCU chip U2 may be set as a third data transmitting pin TX.

The communication between the main control chip and the auxiliary control chip is carried out through an RS485 communication chip U7, signals are clamped at a high level and limited through a third pull-up resistor R7, a fourth pull-up resistor R8 and a fifth pull-up resistor R10 respectively, the signals are filtered through a power supply bypass capacitor C7, the signals are regulated in a bidirectional mode through a bidirectional voltage stabilizing diode TVS2, the signals are clamped at a low level and limited through a pull-down resistor R9, the signals are switched between a second current limiting resistor R12 and the RS485 communication chip U7 through an NPN type triode Q, the power supply state display is carried out through a first light-emitting electronic circuit at a sixth voltage input end of the fourth pull-up resistor R8 and a receiver output pin RO of the RS communication chip U7, the power supply state display is carried out through a second light-emitting electronic circuit at a sixth voltage input end of the fourth pull-up resistor R8 and a second current limiting resistor R12, the power supply state display is carried out through a first current limiting resistor R11 and a second current limiting resistor R12 which are connected in series between a sixth voltage input end of the base of the fourth pull-up resistor R8 and the NPN type triode Q, the reliability and the display performance of the differential communication circuit are improved.

Optionally, referring to fig. 6, 13 and 16, the multifunctional monitoring device further includes a first voltage sampling circuit, the first voltage sampling circuit includes a lightning protection sub-circuit, a voltage divider sub-circuit and a filter sub-circuit, and a voltage output end of the lightning protection sub-circuit is electrically connected to a voltage input end of the filter sub-circuit and a voltage positive input pin of the electric energy metering chip through the voltage divider sub-circuit.

Illustratively, referring to fig. 13, the lightning protection sub-circuit includes a connection terminal JP adapted to be connected to the mains supply and a voltage dependent resistor VR electrically connected between a live wire end and a zero line end of the connection terminal JP, the live wire end of the connection terminal JP is set as a fifth voltage output end, the fifth voltage output end is a voltage output end of the lightning protection sub-circuit, and the zero line end of the connection terminal JP is electrically connected to the zero line, which is helpful for considering lightning protection performance and simplicity of the circuit.

For example, referring to fig. 13, the voltage divider sub-circuit may be formed by connecting six third voltage-dropping resistors R14 in series, the filter sub-circuit may be a first RC parallel filter circuit formed by connecting a first voltage-stabilizing resistor R15 and a seventh filter capacitor C8 in parallel, one end of the last third voltage-dropping resistor R14 may be electrically connected to the positive voltage input pin V3P of the single-phase anti-theft electric-power metering chip U1, one end of the first voltage-stabilizing resistor R15 may be a seventh voltage input end electrically connected between the last third voltage-dropping resistor R14 and the positive voltage input pin V3P of the single-phase anti-theft electric-power metering chip U1, the seventh voltage input end is a voltage input end of the filter sub-circuit, and the other end of the first voltage-stabilizing resistor R15 may be connected to a zero line, so that a reference potential of the first voltage sampling circuit is the same as a reference potential of the electric-power metering chip.

Referring to fig. 6, 14 and 16, the multifunctional monitoring device further includes a second voltage sampling circuit having a voltage input terminal electrically connected to the voltage negative input pin of the electric energy metering chip.

For example, the second voltage sampling circuit may be a second RC parallel filter circuit formed by connecting a second voltage-stabilizing resistor R16 and an eighth filter capacitor C9 in parallel, one end of the second voltage-stabilizing resistor R16 may be a seventh voltage input end electrically connected to the voltage negative input pin V3N of the single-phase anti-electricity-stealing metering chip U1, the seventh voltage input end is a voltage input end of the second voltage sampling circuit, and the other end of the second voltage-stabilizing resistor R16 may be connected to a zero line, so that the reference potential of the non-isolated second voltage sampling circuit is the same as the reference potential of the electric energy metering chip.

Referring to fig. 6, 15 and 16, the multifunctional monitoring device further includes a current sampling circuit, and a pair of current output terminals of the current sampling circuit is electrically connected to a pair of current input pins of the electric energy metering chip.

Exemplarily, the current sampling circuit includes a current transformer CT, a first sampling resistor R17, a second sampling resistor R18, a third current limiting resistor R19, a ninth filter capacitor C10, a fourth current limiting resistor R20, and a tenth filter capacitor C11, the current transformer CT may be connected to the mains, one current positive output pin 3 and one current negative output pin 6 of the current transformer CT are adapted to output current in a differential manner, wherein the current positive output pin 3 is electrically connected to one end of the first sampling resistor R17 and one end of the third current limiting resistor R19, the current negative output pin 6 is electrically connected to one end of the second sampling resistor R18 and one end of the fourth current limiting resistor R20, the other end of the first sampling resistor R17 and the other end of the second sampling resistor R18 may both be connected to the zero line, the other end of the third current limiting resistor R19 is grounded or connected to zero through the ninth filter capacitor C10, a common end between the third current limiting resistor R19 and the ninth filter capacitor C10 may be connected to the anti-stealing metering chip U1 The current sampling circuit is characterized by comprising a current output end electrically connected with a current positive input pin V1P, the other end of a fourth current-limiting resistor R20 is grounded or connected to zero through a tenth filter capacitor C11, and a common end between the fourth current-limiting resistor R20 and the tenth filter capacitor C11 can be the other current output end electrically connected with a current negative input pin V1N of a single-phase anti-electricity-stealing metering chip U1, so that the reliability of the current sampling circuit is ensured.

Because any one of first voltage sampling circuit, second voltage sampling circuit and current sampling circuit is non-isolation sampling circuit, so the electric energy measurement chip needs non-isolation power consumption, in order to cooperate with aforementioned non-isolation sampling circuit, requires that supply circuit has non-isolation for the voltage of electric energy measurement chip to promote the electric energy monitoring precision.

Can sample the signal and input voltage sampling signal to the electric energy measurement chip with the difference mode through first voltage sampling circuit and second voltage sampling circuit, sample the signal and input current sampling signal to the electric energy measurement chip with the difference mode through current sampling circuit, help promoting the electric energy monitoring precision.

Optionally, referring to fig. 6, the multifunctional monitoring device further includes a peripheral circuit electrically connected to the electric energy metering chip, which may include a first crystal oscillator filter sub-circuit, a second pull-down resistor, and two filter sub-circuits, the first crystal oscillator filter circuit IS electrically connected between the oscillation input pin OSCI and the oscillation output pin OSCO of the electric energy metering chip, the communication interface type selection pin IS of the electric energy metering chip IS grounded through the second pull-down resistor, the reference voltage input output pin REFV of the electric energy metering chip IS grounded through one filter sub-circuit, the power supply pin DVDD of the electric energy metering chip IS grounded through the other filter sub-circuit, and the two filter sub-circuits may be respectively a capacitor filter circuit formed by connecting two capacitors in parallel, which helps to ensure the reliability of the crystal oscillator filter circuit.

Illustratively, the first crystal oscillator filter sub-circuit comprises a crystal oscillator, an eleventh filter capacitor and a twelfth filter capacitor, one end of the crystal oscillator is electrically connected with one end of the eleventh filter capacitor and the oscillation input pin OSCI of the electric energy metering chip respectively, the other end of the crystal oscillator is electrically connected with one end of the twelfth filter capacitor and the oscillation output pin OSCO of the electric energy metering chip respectively, and the other end of the eleventh filter capacitor is grounded with the other end of the twelfth filter capacitor.

Alternatively, referring to fig. 12, the multifunction monitor device further includes a peripheral circuit electrically connected to the auxiliary control chip, the peripheral circuit including a second crystal oscillation filter sub-circuit, a third pull-down resistor and two sixth pull-up resistors, the second crystal oscillation filter sub-circuit being electrically connected between the oscillation input pin PD0-OSC _ IN and the oscillation output pin PD1-OSC _ OUT of the auxiliary control chip, the start pin BOOTO of the auxiliary control chip being grounded through the third pull-down resistor, the asynchronous reset pin NRST of the auxiliary control chip being electrically connected to the fourth voltage output terminal through one sixth pull-up resistor, the power supply pin VDDA of the auxiliary control chip being electrically connected to the fourth voltage output terminal through another sixth pull-up resistor, any one of the power supply pin VDD _1, the power supply pin VDD _2 and the power supply pin VDD _3 of the auxiliary control chip being electrically connected between the two sixth pull-up resistors, it can be understood that, the second crystal oscillator filtering sub-circuit may be similar to the first crystal oscillator filtering sub-circuit, and is not described herein again.

Optionally, referring to fig. 16, the multifunctional monitoring apparatus further includes a USB communication circuit, an acoustic alarm circuit, an ethernet communication circuit, a display circuit, and a key circuit, where the USB communication circuit and the acoustic alarm circuit are electrically connected between the second voltage output terminal and the main control chip, respectively, and the ethernet communication circuit, the display circuit, and the key circuit are electrically connected between the fourth voltage output terminal and the main control chip, respectively.

Illustratively, the voltage input end of the USB communication circuit is set as an eighth voltage input end electrically connected to the second voltage output end, a pair of differential signal transmission ends of the USB communication circuit may be electrically connected to the pin PA11 and the pin PA12 on the MCU chip with the model number STM32F429, and the pin PA11 and the pin PA12 may constitute a second pair of differential signal transmission pins, which is helpful to improve the communication performance of the multifunctional monitoring apparatus.

Illustratively, a voltage input end of the acoustic alarm circuit is set to be a ninth voltage input end electrically connected with the second voltage output end, and a voice control signal input end of the acoustic alarm circuit may be electrically connected with a pin PB15 on an MCU chip of model STM32F429, so that the main control chip controls the acoustic alarm circuit to alarm when the power is abnormal or the temperature and humidity are abnormal, so that an electrician can maintain the multifunctional monitoring device.

Illustratively, the voltage input terminal of the ethernet communication circuit is set as a tenth voltage input terminal electrically connected to the fourth voltage output terminal, the ethernet communication circuit may be provided with an ethernet chip of model LAN8720AI, the pin TXD0 and the pin TXD1 of the ethernet chip may be electrically connected to the pin PB12 and the pin PB13 on the MCU chip of model STM32F429 in turn, the pin PB12 and the pin PB13 may constitute a third pair of differential signal transmission pins, the pin RXD0 and the pin RXD1 of the ethernet chip may be electrically connected to the pin PC4 and the pin PC5 on the MCU chip of model STM32F429 in turn, and the pin PC4 and the pin PC5 may constitute a fourth pair of differential signal transmission pins, so as to transmit data between the ethernet communication circuit and the main control chip in a differential manner, which is helpful for improving the communication performance of the multifunctional monitoring apparatus.

Exemplarily, a voltage input end of the display circuit is set to be an eleventh voltage input end electrically connected with the fourth voltage output end, the display circuit may be provided with an LCD display, pin LCD _ RS, pin LCD _ RST, pin LCD _ CS, pin LCD _ SDA, and pin LCD _ SCK of the LCD display screen may be sequentially electrically connected with pin PE5, pin PE6, pin PI7, pin PE4, and pin PE3 on the MCU chip with model number STM32F429, and the main control chip may control the display circuit to display the temperature and humidity, so that an electrician may know the environmental condition of the multifunctional monitoring device.

Illustratively, the voltage input end of the key circuit is set as a twelfth voltage input end electrically connected with the fourth voltage output end, and the key signal control end of the key circuit may be electrically connected with any one of the pin PD12, the pin PD13 and the pin PB14 on the MCU chip with the model number STM32F429, so that an electrician can control the main control chip through the key circuit.

It should be noted that the USB communication circuit, the sound alarm circuit, the ethernet communication circuit, the display circuit, and the key circuit may be implemented by using the existing technologies, and are not described herein again.

For example, the multifunctional monitoring device can be applied to electronic devices such as an intelligent electric meter, an intelligent socket and an intelligent gas meter, taking the intelligent electric meter as an example, a temperature and humidity sensor is installed on the outer surface of the intelligent electric meter, temperature and humidity acquisition is performed on the external environment where the intelligent electric meter is located through the temperature and humidity sensor, and temperature and humidity signals are provided for an anti-static communication circuit, a power supply circuit, an electric energy metering chip, an optoelectronic communication circuit, the anti-static communication circuit and a main control chip are all integrated in a circuit board, the circuit board is installed on the inner surface of the intelligent electric meter, the electric energy metering chip can calculate a voltage value or/and a current value according to a voltage sampling signal, the electric energy metering chip can provide the voltage value or/and the current value to the main control chip in an isolated communication mode through the optoelectronic communication circuit, and the main control chip can turn off or turn on the power supply circuit according to the voltage value or/or the current value The intelligent electric meter is characterized in that a temperature and humidity signal can be provided for the main control chip in an isolated communication mode through the anti-static communication circuit, and the main control chip can also perform turn-off or turn-on control on the power supply circuit according to the temperature and humidity signal, so that the intelligent electric meter is shut down under the condition that the commercial power fails or the temperature and humidity of the environment are abnormal, or the intelligent electric meter is powered on under the condition that the commercial power and the temperature and humidity of the environment are recovered to be normal.

It should be noted that the embodiment provided by the present invention only relates to the improvement of the shape and the structure of the product, and does not relate to the improvement of the software program, so that a person skilled in the art can simply adopt the software program in the prior art to implement the circuit with the monitoring capability, and details are not described here.

Although embodiments of the present invention have been shown and described, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the spirit and scope of the present disclosure, and that such changes will fall within the scope of the present invention.

Claims

1. The utility model provides a multifunctional monitoring device, its characterized in that, multifunctional monitoring device include temperature and humidity sensor, supply circuit and respectively with electric energy metering chip, photoelectric communication circuit, prevent static communication circuit and the main control chip that the supply circuit electricity is connected, the main control chip passes through respectively prevent static communication circuit with temperature and humidity sensor electricity is connected, pass through photoelectric communication circuit with electric energy metering chip electricity is connected.

2. The multifunctional monitoring device according to claim 1, wherein the power supply circuit comprises a buck-type isolated power supply sub-circuit, a first buck-type voltage regulator sub-circuit, an isolated to non-isolated power supply sub-circuit, and a second buck-type voltage regulator sub-circuit, a first voltage output terminal of the buck-type isolated power supply sub-circuit being electrically connected to a first voltage input terminal of the first buck-type voltage regulator sub-circuit and a second voltage input terminal of the second buck-type voltage regulator sub-circuit, a second voltage output terminal of the first buck-type voltage regulator sub-circuit being electrically connected to a third voltage input terminal of the isolated to non-isolated power supply sub-circuit;

3. The multifunctional monitoring device according to claim 2, wherein the first buck regulator sub-circuit comprises a three-terminal regulator tube and a first filter capacitor, an input terminal of the three-terminal regulator tube is provided as the first voltage input terminal, an output terminal of the three-terminal regulator tube is provided as the second voltage output terminal through the first filter capacitor, and a ground terminal of the three-terminal regulator tube is grounded;

4. The multifunctional monitoring device according to claim 2, wherein the second buck-type regulator sub-circuit includes a buck-type regulator chip, a fourth filter capacitor, a freewheeling diode, an inductor, a fifth filter capacitor, a first buck resistor, a second buck resistor, and a shunt resistor, an input terminal of the buck-type regulator chip is provided as the second voltage input terminal that is grounded through the fourth filter capacitor, output terminals of the buck-type regulator chip are electrically connected to a cathode of the freewheeling diode and to the fifth filter capacitor through the inductor, respectively, a ground terminal of the buck-type regulator chip is grounded to the fourth filter capacitor, an anode of the freewheeling diode, and the fifth filter capacitor, and a terminal of the first buck resistor is electrically connected to a common terminal between the inductor and the fifth filter capacitor, the other end of the first voltage reduction resistor is electrically connected with the feedback end of the buck-type voltage stabilization chip and one end of the second voltage reduction resistor respectively, a common end of one end of the shunt resistor, which is electrically connected with one end of the first voltage reduction resistor, is set as the fourth voltage output end, and the other end of the shunt resistor is electrically connected with the other end of the second voltage reduction resistor.

5. The multifunctional monitoring device according to claim 2, wherein the number of the optical-electrical communication circuits is multiple, each optical-electrical communication circuit includes an optical coupler, a first pull-up resistor, a second pull-up resistor, and a sixth filter capacitor, an anode of the optical coupler is electrically connected to one end of the first pull-up resistor, a collector of the optical coupler is electrically connected to one end of the second pull-up resistor and one end of the sixth filter capacitor, respectively, and an emitter of the optical coupler is grounded to the other end of the sixth filter capacitor;

6. The multi-function monitoring device of claim 2, further comprising a USB communication circuit, an acoustic alarm circuit, an ethernet communication circuit, a display circuit, and a key circuit, the USB communication circuit and the acoustic alarm circuit being electrically connected between the second voltage output terminal and the main control chip, respectively, and the ethernet communication circuit, the display circuit, and the key circuit being electrically connected between the fourth voltage output terminal and the main control chip, respectively.

7. The multi-function monitoring device of claim 2, further comprising an RJ45 interface circuit, an auxiliary control chip, and a plurality of differential communication circuits, wherein the fourth voltage output terminal is electrically connected to the seventh voltage input terminal of each of the differential communication circuits and the power pin of the auxiliary control chip, the pair of differential signal transmission pins of the main control chip are electrically connected to the third data receiving pin and the third data transmitting pin of the auxiliary control chip through one of the differential communication circuits, and the fourth data receiving pin and the fourth data transmitting pin of the main control chip are electrically connected to the pair of differential signal terminals of the RJ45 interface circuit through the other of the differential communication circuits.

8. The multifunctional monitoring device according to claim 7, wherein at least one of the differential communication circuits comprises an RS485 communication chip, a third pull-up resistor, a fourth pull-up resistor, a power supply bypass capacitor, a bidirectional zener diode, a pull-down resistor, an NPN type triode, a first light emitting sub-circuit, a fifth pull-up resistor, a second light emitting sub-circuit, a first current limiting resistor, and a second current limiting resistor;

9. The multifunctional monitoring device according to any one of claims 1-8, further comprising a first voltage sampling circuit, a second voltage sampling circuit, and a current sampling circuit, wherein the first voltage sampling circuit comprises a lightning protection sub-circuit, a voltage divider sub-circuit, and a filter sub-circuit, wherein a voltage output terminal of the lightning protection sub-circuit is electrically connected to a voltage input terminal of the filter sub-circuit and a voltage positive input pin of the power metering chip through the voltage divider sub-circuit, a voltage input terminal of the second voltage sampling circuit is electrically connected to a voltage negative input pin of the power metering chip, and a pair of current output terminals of the current sampling circuit is electrically connected to a pair of current input pins of the power metering chip.

10. The multifunctional monitoring device according to claim 9, wherein the lightning protection sub-circuit comprises a connection terminal and a voltage dependent resistor, wherein the live wire end of the connection terminal is electrically connected with one end of the voltage dependent resistor and the voltage input end of the voltage dependent sub-circuit respectively, and the live wire end of the connection terminal is grounded with the other end of the voltage dependent resistor.