CN219757551U - Multi-path multi-sensor temperature acquisition terminal of Internet of things - Google Patents

Abstract

The utility model provides a multi-path multi-sensor temperature acquisition terminal of the Internet of things, which adopts ingenious terminal design to enable the terminal to be compatible with two sensors, namely a thermal resistor and a thermocouple, so as to realize multi-sensor temperature acquisition; the sensor interface module, the constant current source module, the electronic switching module, the voltage conditioning module, the MCU module, the man-machine interaction module and the Internet of things module are electrically connected, so that multichannel acquisition can be realized, external wiring is not needed, the cloud can be directly connected, and the signals can be directly transmitted to equipment such as a computer, a PLC and the like; the electronic change-over switch is adopted, so that the amplifying circuit, the filter circuit and the constant current source circuit can be used in a combined mode, the waste of resources is reduced, and the cost of multi-path temperature acquisition is reduced.

Description

Multi-path multi-sensor temperature acquisition terminal of Internet of things

Technical Field

The utility model relates to the technical field of temperature data detection, in particular to an internet of things multichannel multi-sensor temperature acquisition terminal.

Background

At present, with the development of intelligent production and the development of the industry of the Internet of things, temperature data monitoring is increasingly used in the industry automation and intelligent breeding industry, and the requirements on a temperature data connection network are more and more. The thermal resistor and the thermocouple adopt the two most temperature sensors, and the thermal resistor has the advantages of low price, good chemical stability, high temperature resistance, good linearity and the like, and the thermocouple has the advantages of low price, simple structure, wide measurement range and the like.

The existing temperature measurement products in the market cannot be collected in multiple channels, or when a plurality of collection points are needed, a plurality of devices are needed, the manufacturing cost is high, wiring is troublesome, and the labor cost is increased; and most of the existing temperature measurement products only can support thermal resistors or thermocouples, but cannot support the same. Most of the existing multi-channel thermal resistor acquisition terminals also need to transmit data by adding another Internet of things module. The installation of the appropriate internet of things module causes huge volume, and connection between the internet of things module and the external internet of things module requires wiring operation, so that the external system is also likely to cause interference to communication signals.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present utility model provides a multi-channel multi-sensor temperature acquisition terminal of the internet of things, which is used for solving the problems that the temperature acquisition terminal in the prior art cannot acquire multiple channels, cannot simultaneously support thermal resistors or thermocouples to measure temperature, and must transmit data by adding another internet of things module.

To achieve the above and other related objects, a first aspect of the present utility model provides an internet of things multi-channel multi-sensor temperature acquisition terminal, the terminal comprising: the system comprises a plurality of sensor interface modules, a constant current source module, an electronic switching module, a voltage conditioning module, an MCU module, a man-machine interaction module and an Internet of things module; the sensor interface modules are respectively and correspondingly connected with a sensor and are used for collecting analog voltage signals of the sensors; the constant current source module is used for outputting constant current; the electronic switching module is electrically connected with the sensor interface module, the constant current source module, the voltage conditioning module and the MCU module and is used for transmitting the constant current to the sensor interface module through the electronic switching module and transmitting analog voltage signals acquired by the sensors to the voltage conditioning module; the voltage conditioning module is electrically connected with the MCU module, and is used for filtering and amplifying each received analog voltage signal and transmitting each processed analog voltage signal to the MCU module; the MCU module is electrically connected with the man-machine interaction module and the Internet of things module, and is used for receiving each analog voltage signal output by the voltage conditioning module and obtaining a temperature value corresponding to each analog voltage signal; the man-machine interaction module is used for receiving and displaying each temperature value output by the MCU module; the internet of things module is used for acquiring each temperature value from the MCU module and transmitting the temperature values to the outside.

In some embodiments of the first aspect of the present utility model, the voltage conditioning module comprises: a signal filtering circuit for filtering each received analog voltage signal; and the signal amplifying circuit is electrically connected with the signal filtering circuit and is used for amplifying each filtered analog voltage signal.

In some embodiments of the first aspect of the present utility model, the voltage conditioning module comprises: the signal filtering circuit comprises a capacitor C1; the signal amplifying circuit comprises a first operational amplifier, wherein the reverse input end of the first operational amplifier is connected with one end of a first resistor R4, and the other end of the first resistor R4 is grounded; the positive input end of the first operational amplifier is connected with one end of a second resistor R5, and the other end of the second resistor R5 is grounded after being connected with the capacitor C1; the output end of the first operational amplifier is connected with one end of a third resistor R12, and the other end of the third resistor R12 is connected with the reverse input end of the first operational amplifier.

In some embodiments of the first aspect of the utility model, the types of sensors include: thermocouple sensors and/or thermal resistance sensors.

In some embodiments of the first aspect of the present utility model, the electronic switching module includes: an electronic switch with one of two and four switches; the electronic change-over switch includes: pins 1 to 16; the pins 1 and 12 are connected with a first sensor; the pins 5 and 14 are connected with a second sensor; the pins 2 and 15 are connected with a third sensor; the pins 4 and 11 are connected with a fourth sensor; the pin 3 is connected with the constant current source module; the pin 13 is connected with the voltage conditioning module; the pins 9 and 10 are connected with the MCU module; the pins 6, 7 and 8 are grounded; the pin number 16 is connected with the power supply VDD.

In some embodiments of the first aspect of the present utility model, the man-machine interaction module includes: the driving unit is electrically connected with the MCU module and is used for receiving a temperature value triggering display instruction output by the MCU module; the display unit is electrically connected with the driving unit; the display unit starts the display unit according to the display instruction to display the temperature value.

In some embodiments of the first aspect of the present utility model, the man-machine interaction module further includes a key input unit, configured to send a key command to the MCU module.

In some embodiments of the first aspect of the present utility model, the MCU module includes: the system comprises a channel selection unit, a temperature acquisition unit, a man-machine interaction unit and an Internet of things communication unit; the channel selection unit is electrically connected with the electronic switching module and is used for transmitting a channel selection instruction to the electronic switching module; the temperature acquisition unit is electrically connected with the voltage conditioning module and is used for receiving each analog voltage signal output by the voltage conditioning module and acquiring a temperature value corresponding to each analog voltage signal; the man-machine interaction unit is electrically connected with the man-machine interaction module, and is used for sending the temperature value to the man-machine interaction module and receiving a key instruction sent by the man-machine interaction module; and the internet of things communication unit is in communication connection with the internet of things module and is used for sending each temperature value to the internet of things module.

In some embodiments of the first aspect of the present utility model, the temperature acquisition unit includes: the receiving device is used for receiving each analog voltage signal output by the voltage conditioning module; an AD conversion device for converting each received analog voltage signal into a voltage digital signal; the temperature acquisition device is used for calculating and acquiring temperature values corresponding to the voltage digital signals according to the voltage digital signals; and the register is electrically connected with the temperature acquisition unit and used for storing each temperature value.

In some embodiments of the first aspect of the present utility model, the constant current source module employs a constant current source circuit; wherein, the constant current source circuit includes: the second operational amplifier A, the third operational amplifier B, the fourth resistor R9, the fifth resistor R10, the sixth resistor R8, the seventh resistor R7, the eighth resistor R6 and the ninth resistor R14; one end of the fourth resistor R9 is connected to the power VCC, and the other end is connected to the positive input end of the second amplifier a and one end of the fifth resistor R10; the other end of the fifth resistor R10 is connected with the reverse input end and the output end of the third operational amplifier B; the reverse input end of the second amplifier A is connected with one end of the sixth resistor R8 and one end of the seventh resistor R7; the other end of the sixth resistor R8 is grounded; the other end of the seventh resistor R7 is connected with the output end of the second operational amplifier A and one end of the eighth resistor R6; the other end of the eighth resistor R6 is connected with the positive input end of the third operational amplifier B and one end of the ninth resistor R14; the other end of the ninth resistor R14 is electrically connected with the electronic switching module.

As described above, the multi-channel multi-sensor temperature acquisition terminal of the internet of things has the following beneficial effects:

1. the utility model adopts ingenious terminal design to enable the temperature sensor to be compatible with two sensors, namely a thermal resistor and a thermocouple, and realizes multi-sensor temperature acquisition.

2. Through with sensor interface module, constant current source module, electronic switching module, voltage conditioning module, MCU module, human-computer interaction module and thing networking module electric connection, not only can realize multichannel collection, still need not the external connection, can the lug connection high in the clouds, also can directly transmit equipment such as computer, PLC.

3. The electronic change-over switch is adopted, so that the amplifying circuit, the filter circuit and the constant current source circuit can be used in a combined mode, the waste of resources is reduced, and the cost of multi-path temperature acquisition is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a networked multi-channel multi-sensor temperature acquisition terminal according to an embodiment of the utility model.

Fig. 2 is a schematic structural diagram of a sensor interface module according to an embodiment of the utility model.

Fig. 3 is a schematic structural diagram of a constant current source module according to an embodiment of the utility model.

Fig. 4 is a schematic structural diagram of an electronic switching module according to an embodiment of the utility model.

Fig. 5 is a schematic structural diagram of a voltage conditioning module according to an embodiment of the utility model.

Fig. 6 is a schematic structural diagram of an MCU module according to an embodiment of the present utility model.

Fig. 7A is a schematic diagram of a part of a man-machine interaction module according to an embodiment of the utility model.

Fig. 7B is a schematic diagram of a part of a man-machine interaction module according to an embodiment of the utility model.

Fig. 7C is a schematic diagram of a part of a man-machine interaction module according to an embodiment of the utility model.

Fig. 8 is a schematic structural diagram of an internet of things module according to an embodiment of the utility model.

Detailed Description

Further advantages and effects of the present utility model will become apparent to those skilled in the art from the disclosure of the present utility model, which is described by the following specific examples.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or otherwise, used in the practice of the utility model, are not intended to be critical to the essential characteristics of the utility model, but are intended to fall within the spirit and scope of the utility model. The following detailed description is not to be taken in a limiting sense, and the scope of embodiments of the present utility model is defined only by the claims of the issued patent. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. Spatially relative terms, such as "upper," "lower," "left," "right," "lower," "upper," and the like, may be used herein to facilitate a description of one element or feature as illustrated in the figures as being related to another element or feature.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," "held," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, operations, elements, components, items, categories, and/or groups. The terms "or" and/or "as used herein are to be construed as inclusive, or meaning any one or any combination. Thus, "A, B or C" or "A, B and/or C" means "any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; A. b and C). An exception to this definition will occur only when a combination of elements, functions or operations are in some way inherently mutually exclusive.

In order to make the objects, technical solutions and advantages of the present utility model more apparent, further detailed description of the technical solutions in the embodiments of the present utility model will be given by the following examples with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

Fig. 1 shows a schematic structural diagram of a multi-channel multi-sensor temperature acquisition terminal of the internet of things in an embodiment of the utility model.

The terminal comprises a plurality of sensor interface modules 11, a constant current source module 12, an electronic switching module 13, a voltage conditioning module 14, an MCU module 15, a man-machine interaction module 16 and an Internet of things module 17; the sensor interface modules 11 are respectively and correspondingly connected with a sensor, and are used for collecting analog voltage signals of the sensors; the constant current source module 12 is used for outputting constant current; the electronic switching module 13 is electrically connected with the sensor interface module 11, the constant current source module 12, the voltage conditioning module 14 and the MCU module 15, and is configured to transmit the constant current to the sensor interface module 11 through the electronic switching module 13, and transmit the analog voltage signals collected by the sensors to the voltage conditioning module 14; the voltage conditioning module 14 is electrically connected to the MCU module 15, and is configured to perform filtering and amplifying processing on each received analog voltage signal, and transmit each processed analog voltage signal to the MCU module 15; the MCU module 15 is electrically connected with the man-machine interaction module 16 and the internet of things module 17, and is used for receiving each analog voltage signal output by the voltage conditioning module 14 and obtaining a temperature value corresponding to each analog voltage signal; the man-machine interaction module 16 is configured to receive and display each temperature value output by the MCU module 15; the internet of things module 17 is configured to obtain each temperature value from the MCU module 15, and transmit the temperature value to an external device.

The external device may be a cloud end or a server, or may be an external device, for example, a computer, a PLC device, or an upper computer. Through with sensor interface module, constant current source module, electronic switching module, voltage conditioning module, MCU module, human-computer interaction module and thing networking module electric connection, not only can realize multichannel collection, still need not the external connection, can the lug connection high in the clouds, also can directly transmit equipment such as computer, PLC.

In one embodiment, the voltage conditioning module 14 includes: a signal filtering circuit for filtering each received analog voltage signal; and the signal amplifying circuit is electrically connected with the signal filtering circuit and is used for amplifying each filtered analog voltage signal. The signal filtering circuit comprises a capacitor C1; the signal amplifying circuit comprises a first operational amplifier, wherein the reverse input end of the first operational amplifier is connected with one end of a first resistor R4, and the other end of the first resistor R4 is grounded; the positive input end of the first operational amplifier is connected with one end of a second resistor R5, and the other end of the second resistor R5 is grounded after being connected with the capacitor C1; the output end of the first operational amplifier is connected with one end of a third resistor R12, and the other end of the third resistor R12 is connected with the reverse input end of the first operational amplifier.

The description of fig. 5 is that, the second resistor R5 is connected to the electronic switching module 13, and receives and processes each analog voltage signal transmitted by the electronic switching module 13, specifically, each analog voltage signal is filtered by the capacitor C1 and the second resistor R5, so as to filter noise and interference signals, and ensure that each collected analog voltage signal is accurate; the filtered analog voltage signals pass through an operational amplifier, the operational amplifier can increase the amplitude of the analog voltage signals and improve the signal to noise ratio, so that the reading error is reduced, and the reading error is amplified to the multiple of R12/R4 and then is output to the MCU module 15.

In an embodiment, the type of sensor comprises a thermocouple sensor and/or a thermal resistance sensor.

It should be noted that, at present, the temperature measurement products on the market cannot be collected in multiple channels, or when multiple collection points are needed, multiple devices are needed, the manufacturing cost is high, and the wiring is troublesome, so this embodiment provides multiple sensor interface modules, each sensor interface module includes an external connection port, and the sensor types include thermocouple sensors and thermal resistance sensors through the connection of the external connection port with the corresponding sensor, so that the temperature collection of multiple sensors can be realized.

Preferably, as described with reference to fig. 2, the external connection port is an external connection port P1 with 3 pins, the sensor interface module 11 further includes a resistor R1 and a resistor R2, and the first rectifying diode D1 and the second rectifying diode D2, and each port P1 is connected to three pins of a thermal resistor sensor or two pins of a thermocouple sensor through 3 pins. The embodiment adopts ingenious terminal design to enable the temperature sensor to be compatible with two sensors, namely a thermal resistor and a thermocouple, and realizes multi-sensor temperature acquisition.

The external wiring port P1 includes 3 pins, the pin 1 is grounded, the pin 2 is connected to one end of the first rectifying diode D1 and the resistor R2, and the other end of the resistor R2 is connected to the electronic switching module 13 and is communicated with the voltage conditioning module 14; the pin 3 is connected to the second rectifying diode D2 and one end of the resistor R1, and the other end of the resistor R1 is connected to the electronic switching module 13 and is communicated with the constant current source module 12.

Specifically, the R1 in the sensor interface module 11 is configured to receive the constant current sent by the electronic switching module 12, when the sensor connected to the external wiring port P1 is a thermal resistance sensor, the constant current generates a voltage through the thermal resistance sensor, and the resistance value of the thermal resistance changes with the change of temperature, so that the voltage changes with the change of temperature, and since the pin 2 and the pin 3 of the external wiring port P1 are connected inside the thermal resistance, the change of the temperature value can be calculated through the voltage value of R2. When the sensor connected with the external wiring port P1 is a thermocouple sensor, the thermocouple generates different voltage values along with the temperature change, and the change of the temperature value can be calculated through the R2 voltage value.

In one embodiment, the electronic switching module 13 includes a two-for-one electronic switching switch; the electronic change-over switch comprises pins 1 to 16; the pins 1 and 12 are connected with a first sensor; the pins 5 and 14 are connected with a second sensor; the pins 2 and 15 are connected with a third sensor; the pins 4 and 11 are connected with a fourth sensor; the pin 3 is connected with the constant current source module; the pin 13 is connected with the voltage conditioning module; the pins 9 and 10 are connected with the MCU module; the pins 6, 7 and 8 are grounded; the pin number 16 is connected with the power supply VDD. The electronic switching module is adopted to connect the constant current source module and the voltage conditioning module, so that the amplifying circuit, the filter circuit and the constant current source circuit can be used in a combined mode, the waste of resources is reduced, and the cost of multi-path temperature acquisition is reduced.

Referring to fig. 4, pin No. 3 is connected to the constant current source module 12, and receives the constant current output by the constant current source module 12; the pin X13 is connected with a second resistor R5 in the voltage conditioning module 14, and transmits the received analog voltage signals to the voltage conditioning module 14; the pin Y0 and the pin X0 are connected with the first sensor; the pin Y1 No. 5 and the pin X1 No. 14 are connected with a second sensor; the pin Y2 and the pin X2 of the number 15 are connected with a third sensor; the pin Y3 of the No. 4 and the pin X3 of the No. 11 are connected with a fourth sensor; the No. 10 pin swa and the No. 9 pin swb are connected with the MCU module 15.

For example, when MCU module 15 sets pin swa to 0 and pin swb to 0, pin Y turns on pin Y0 and pin X turns on pin X0, i.e., communicates with the first sensor; when the MCU module 15 sets the pin swa to 1 and the pin swb to 0, the pin Y is communicated with the pin Y1, and the pin X is communicated with the pin X1, namely, communicated with the second sensor; when the MCU module 15 sets the pin swa to 0 and the pin swb to 1, the pin Y is communicated with the pin Y2, and the pin X is communicated with the pin X2, namely, communicated with a third sensor; when the MCU module sets the pin swa to 1 and the pin swb to 1, the pin Y is communicated with the pin Y3, and the pin X is communicated with the pin X3, namely, the fourth sensor is communicated.

Taking the first sensor as an example, the constant current source module 12 outputs a constant current, the electronic switching module 13 receives the constant current through a pin No. 3Y connected with the constant current source module 12, the electronic switching module 13 is connected with the first sensor through a pin No. 1Y 0 and a pin No. 12X 0, the constant current is transmitted to an R1 of the first sensor through a pin No. 1Y 0, the constant current generates a voltage through the first sensor, the voltage varies along with the temperature acquired by the first sensor to obtain different voltage values, namely an analog voltage signal, the analog voltage signal is transmitted to the electronic switching module 13 through a transmission channel connected with a pin No. 12X 0 of the first sensor, and the electronic switching module 13 transmits the analog voltage signal to the voltage conditioning module 14 through a pin No. 13X.

In one embodiment, the human-machine interaction module 16 comprises: the driving unit is electrically connected with the MCU module 15 and is used for receiving a temperature value triggering display instruction output by the MCU module 15; the display unit is electrically connected with the driving unit; the display unit starts the display unit according to the display instruction to display the temperature value.

Specifically, as described with reference to fig. 7B and 7C, the driving unit includes a driving chip, and the display unit includes a 4-bit LED display screen; the No. 16 pin DAT1 of the driving chip is connected with the MCU module 15 and receives a temperature value triggering display instruction output by the MCU module 15; the driving chip is connected with the LED display screen of the display unit through pins 2-9 and pins 12-15, and outputs the display instruction to the display unit so as to display the temperature value on the LED display screen.

In an embodiment, the man-machine interaction module 16 further includes a key input unit, configured to send a key command to the MCU module 15. The key instruction is used for various settings and operations performed on temperature acquisition, such as starting or stopping the temperature acquisition equipment, checking current temperature data, saving temperature data, deriving a historical temperature data report, changing display unit settings, and the like. Wherein, as shown in fig. 7A, the key input unit includes three keys and three pull-up resistors. It should be noted that, the three pull-up resistors may enable the circuit of the whole key input unit to form a high level, press the key, change the circuit into a low level, form a path, and the key input unit is electrically connected to the MCU module 15, and is used for transmitting the key command to the MCU module 15.

In an embodiment, the MCU module 15 includes a channel selection unit, a temperature acquisition unit, a man-machine interaction unit, and an internet of things communication unit; the channel selection unit is electrically connected with the electronic switching module 13 and is used for transmitting a channel selection instruction to the electronic switching module 13; the temperature acquisition unit is electrically connected with the voltage conditioning module 14 and is used for receiving each analog voltage signal output by the voltage conditioning module 14 and acquiring a temperature value corresponding to each analog voltage signal; the man-machine interaction unit is electrically connected with the man-machine interaction module 16, and is used for sending the temperature value to the man-machine interaction module 16 and receiving a key instruction sent by the man-machine interaction module 16; the internet of things communication unit is in communication connection with the internet of things module 17 and is used for sending each temperature value to the internet of things module 17. For example, the channel selection command refers to a command output from the MCU module 15 for selecting a transmission channel for connecting to a certain sensor in the electronic switching module 13.

It should be noted that, as shown in fig. 6, the MCU module 15 includes a crystal oscillator X1, two resistors R21 and R22, and 9 capacitors C21 to C29, where the crystal oscillator, the resistors, and the capacitors are necessary components for the MCU module 15 to work normally. The pin 12 of the MCU module 15 is used for receiving each analog voltage signal output by the voltage conditioning module 14 and converting the analog voltage signal into a temperature value through calculation; the pin 13 of the MCU module 15 is electrically connected with the man-machine interaction module 16, and sends each temperature value to the man-machine interaction module 16; pins 17 and 18 of the MCU module 15 are connected with the electronic switching module and are used for transmitting channel selection instructions; pins 30, 31, and 32 of the MCU module 15 are electrically connected to the man-machine interaction module 16, and are configured to receive a key instruction output by a key input unit of the man-machine interaction module 16, for example, perform operations such as saving temperature data; the pins 42 and 43 of the MCU module 15 are electrically connected with the Internet of things module 17 and are used for uploading the acquired temperature data with the Internet of things module 17. As described with reference to fig. 8, the internet of things module 17 includes: the pin 0 is connected with a power VCC, and the pin 1 is grounded; the No. 2 pin is connected with the No. 43 pin in the MCU module, and the No. 3pin is connected with the No. 42 pin in the MCU module, so that a communication channel is formed to transmit each temperature value.

In an embodiment, the temperature acquisition unit includes: the receiving device is used for receiving each analog voltage signal output by the voltage conditioning module; an AD conversion device for converting each received analog voltage signal into a voltage digital signal; the temperature acquisition device is used for calculating and acquiring temperature values corresponding to the voltage digital signals according to the voltage digital signals; and the register is electrically connected with the temperature acquisition unit and used for storing each temperature value. The AD conversion device is used for converting each analog signal into a digital signal, and a processor is convenient to carry out digital processing.

In one embodiment, as shown in fig. 3, the constant current source module 12 employs a constant current source circuit; the constant current source circuit comprises a second operational amplifier A, a third operational amplifier B, a fourth resistor R9, a fifth resistor R10, a sixth resistor R8, a seventh resistor R7, an eighth resistor R6 and a ninth resistor R14; one end of the fourth resistor R9 is connected to the power VCC, and the other end is connected to the positive input end of the second amplifier a and one end of the fifth resistor R10; the other end of the fifth resistor R10 is connected with the reverse input end and the output end of the third operational amplifier B; the reverse input end of the second amplifier A is connected with one end of the sixth resistor R8 and one end of the seventh resistor R7; the other end of the sixth resistor R8 is grounded; the other end of the seventh resistor R7 is connected with the output end of the second operational amplifier A and one end of the eighth resistor R6; the other end of the eighth resistor R6 is connected with the positive input end of the third operational amplifier B and one end of the ninth resistor R14; the other end of the ninth resistor R14 is electrically connected with the electronic switching module.

The constant current source module 13 outputs constant current, the current is transmitted to the corresponding sensor pin through the electronic switching module 13, when the external sensor is a thermal resistor, the resistance of the thermal resistor changes along with the change of temperature, and according to ohm's law, under the condition of constant current, the voltage at two ends of the thermal resistor also changes along with the change of temperature; when the external sensor is a thermocouple, the voltage across the thermocouple varies with temperature.

In summary, the utility model provides the multi-channel multi-sensor temperature acquisition terminal of the Internet of things, which adopts ingenious terminal design to enable the terminal to be compatible with two sensors, namely a thermal resistor and a thermocouple, so as to realize multi-sensor temperature acquisition; the sensor interface module, the constant current source module, the electronic switching module, the voltage conditioning module, the MCU module, the man-machine interaction module and the Internet of things module are electrically connected, so that multichannel acquisition can be realized, external wiring is not needed, the cloud can be directly connected, and the signals can be directly transmitted to equipment such as a computer, a PLC and the like; the electronic change-over switch is adopted, so that the amplifying circuit, the filter circuit and the constant current source circuit can be used in a combined mode, the waste of resources is reduced, and the cost of multi-path temperature acquisition is reduced. Therefore, the utility model effectively overcomes various defects in the prior art and has high industrial utilization value.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (10)

1. The utility model provides a multichannel multisensor temperature acquisition terminal of thing networking, its characterized in that, the terminal includes: the system comprises a plurality of sensor interface modules, a constant current source module, an electronic switching module, a voltage conditioning module, an MCU module, a man-machine interaction module and an Internet of things module; wherein,,

the sensor interface modules are respectively and correspondingly connected with a sensor and are used for collecting analog voltage signals of the sensors;

the constant current source module is used for outputting constant current;

the electronic switching module is electrically connected with the sensor interface module, the constant current source module, the voltage conditioning module and the MCU module and is used for transmitting the constant current to the sensor interface module through the electronic switching module and transmitting analog voltage signals acquired by the sensors to the voltage conditioning module;

the voltage conditioning module is electrically connected with the MCU module, and is used for filtering and amplifying each received analog voltage signal and transmitting each processed analog voltage signal to the MCU module;

the MCU module is electrically connected with the man-machine interaction module and the Internet of things module, and is used for receiving each analog voltage signal output by the voltage conditioning module and obtaining a temperature value corresponding to each analog voltage signal;

the man-machine interaction module is used for receiving and displaying each temperature value output by the MCU module;

the internet of things module is used for acquiring each temperature value from the MCU module and transmitting the temperature values to the outside.

2. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 1, wherein the voltage conditioning module comprises:

a signal filtering circuit for filtering each received analog voltage signal;

and the signal amplifying circuit is electrically connected with the signal filtering circuit and is used for amplifying each filtered analog voltage signal.

3. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 2, wherein the voltage conditioning module comprises:

the signal filtering circuit comprises a capacitor;

the signal amplifying circuit comprises a first operational amplifier, wherein the reverse input end of the first operational amplifier is connected with one end of a first resistor, and the other end of the first resistor is grounded; the positive input end of the first operational amplifier is connected with one end of a second resistor, and the other end of the second resistor is connected with the capacitor and then grounded; the output end of the first operational amplifier is connected with one end of a third resistor, and the other end of the third resistor is connected with the reverse input end of the first operational amplifier.

4. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 1, wherein the sensor types include: thermocouple sensors and/or thermal resistance sensors.

5. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 1, wherein the electronic switching module comprises: an electronic switch with one of two and four switches; the electronic change-over switch includes: pins 1 to 16;

the pins 1 and 12 are connected with a first sensor; the pins 5 and 14 are connected with a second sensor; the pins 2 and 15 are connected with a third sensor; the pins 4 and 11 are connected with a fourth sensor; the pin 3 is connected with the constant current source module; the pin 13 is connected with the voltage conditioning module; the pins 9 and 10 are connected with the MCU module; the pins 6, 7 and 8 are grounded; the pin number 16 is connected with the power supply VDD.

6. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 1, wherein the man-machine interaction module comprises:

the driving unit is electrically connected with the MCU module and is used for receiving a temperature value triggering display instruction output by the MCU module;

the display unit is electrically connected with the driving unit; the display unit starts the display unit according to the display instruction to display the temperature value.

7. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 6, wherein the man-machine interaction module further comprises a key input unit for sending a key instruction and transmitting the key instruction to the MCU module.

8. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 1, wherein the MCU module comprises: the system comprises a channel selection unit, a temperature acquisition unit, a man-machine interaction unit and an Internet of things communication unit;

the channel selection unit is electrically connected with the electronic switching module and is used for transmitting a channel selection instruction to the electronic switching module;

the temperature acquisition unit is electrically connected with the voltage conditioning module and is used for receiving each analog voltage signal output by the voltage conditioning module and acquiring a temperature value corresponding to each analog voltage signal;

the man-machine interaction unit is electrically connected with the man-machine interaction module, and is used for sending the temperature value to the man-machine interaction module and receiving a key instruction sent by the man-machine interaction module;

and the internet of things communication unit is in communication connection with the internet of things module and is used for sending each temperature value to the internet of things module.

9. The internet of things multi-channel multi-sensor temperature acquisition terminal of claim 8, wherein the temperature acquisition unit comprises:

the receiving device is used for receiving each analog voltage signal output by the voltage conditioning module;

an AD conversion device for converting each received analog voltage signal into a voltage digital signal;

the temperature acquisition device is used for calculating and acquiring temperature values corresponding to the voltage digital signals according to the voltage digital signals;

and the register is electrically connected with the temperature acquisition unit and used for storing each temperature value.

10. The internet of things multi-channel multi-sensor temperature acquisition terminal according to claim 1, wherein the constant current source module adopts a constant current source circuit; wherein, the constant current source circuit includes: a second operational amplifier, a third operational amplifier, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a ninth resistor;

one end of the fourth resistor is connected with a power supply, and the other end of the fourth resistor is connected with the positive input end of the second operational amplifier and one end of the fifth resistor;

the other end of the fifth resistor is connected with the reverse input end and the output end of the third operational amplifier;

the reverse input end of the second operational amplifier is connected with one end of the sixth resistor and one end of the seventh resistor;

the other end of the sixth resistor is grounded; the other end of the seventh resistor is connected with the output end of the second operational amplifier and one end of the eighth resistor;

the other end of the eighth resistor is connected with the positive input end of the third operational amplifier and one end of the ninth resistor;

the other end of the ninth resistor is electrically connected with the electronic switching module.