Infrared temperature measuring device with output of 4-20 ma

Abstract

The utility model relates to the technical field of infrared temperature measurement, and discloses an infrared temperature measurement device outputting 4-20mA, which comprises a power supply, a voltage conversion circuit, a 4-20mA converter, a CPU circuit and an infrared temperature measurement probe, the power supply is connected with the 4-20mA converter, the 4-20mA converter is respectively connected with the CPU circuit and the voltage conversion circuit, the CPU circuit is connected with the infrared temperature measurement probe, the voltage conversion circuit is connected with the CPU circuit, and the infrared temperature measurement probe is connected with the voltage conversion circuit. The infrared temperature measuring device has the advantages of being simple in structure and convenient to wire.

Description

Technical Field

[0001] The utility model relates to the technical field of infrared temperature measurement, in particular to an infrared temperature measurement device with an output of 4-20mA. Background Art

[0002] Infrared temperature measurement is a technology based on the theory of thermal radiation. The temperature of an object is related to the energy radiated from its own surface. The higher the surface temperature of the object, the greater the radiated energy. It uses the relationship between infrared radiation and the temperature of the object to measure the surface temperature of the object. The infrared sensor measures the surface temperature of the object. The advantage of infrared temperature measurement technology is that it does not contact the object being measured, so it will not cause damage or pollution to the object being measured. In addition, due to the wide operating temperature range, it can be measured in high temperature, low temperature, dark environment and other environments.

[0003] The most widely used standard analog electrical signal in industry is to use 4~20mA DC current to transmit analog quantity. The reason for using current signal is that it is not easy to be interfered, and the internal resistance of the current source is infinite. The wire resistance connected in series in the loop does not affect the accuracy, and it can be transmitted for hundreds of meters on ordinary twisted pair cables. Utility Model Content

[0004] The utility model aims to provide an infrared temperature measuring device with an output of 4-20mA, which has the characteristics of simple structure and convenient wiring.

[0005] The utility model is realized by the following technical scheme: an infrared temperature measuring device with an output of 4-20mA, comprising a power supply, a voltage conversion circuit, a 4-20mA converter, a CPU circuit and an infrared temperature measuring probe, wherein the power supply is connected to the 4-20mA converter, the 4-20mA converter is respectively connected to the CPU circuit and the voltage conversion circuit, the CPU circuit is connected to the infrared temperature measuring probe, and the voltage conversion circuit is connected to the infrared temperature measuring probe.

[0006] In order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the 4-20mA converter includes a chip U1, a transistor Q1, a diode D1, a capacitor C1, a capacitor C4, a capacitor C5, a resistor R1 and a resistor R2, the VREG pin (pin 8) of the chip U1 is connected to the voltage conversion circuit, the VREF pin (pin 1) of the chip U1 is grounded through a resistor R2 and a capacitor C4 connected in series, and the VREF pin (pin 1) of the chip U1 is also grounded through a capacitor C5; the VREF pin (pin 1) of the chip U1 is also connected to the CPU circuit, and the IN pin of the chip U1 The pin (pin 2) is connected to the CPU circuit through the resistor R1; the third end (collector) of the transistor Q1 is connected to the V+ pin (pin 7) of the chip U1, the second end (base) of the transistor Q1 is connected to the Base pin (pin 6) of the chip U1, the first end (emitter) of the transistor Q1 is connected to the Emitter pin (pin 5) of the chip U1, one end of the power supply is connected to the V+ pin (pin 7) of the chip U1 through the diode D1, the other end of the power supply is connected to the IO pin (pin 4) of the chip U1, the capacitor C1 is connected between the V+ pin (pin 7) and the IO pin (pin 4) of the chip U1, and the IRET pin (pin 3) of the chip U1 is grounded.

[0007] In order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the transistor Q1 adopts a triode, and the first and third ends of the triode are the emitter, the base and the collector respectively; the positive pole of the diode D1 is connected to the power supply.

[0008] In order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the voltage conversion circuit realizes the function of converting 5v to 3.3v, including chip U4, capacitor C2 and capacitor C3, the IN pin (pin 3) of chip U4 is connected to 5V DC and grounded through capacitor C2, the IN pin (pin 3) of chip U4 is also connected to the 4-20mA converter (VREG pin of chip U1); the OUT pin (pin 2) of chip U4 is connected to the VDD pin (pin 3) of the infrared temperature measuring probe, and the OUT pin (pin 2) of chip U4 is also grounded through capacitor C3, and the GND pin (pin 1) of chip U4 is grounded.

[0009] In order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the CPU circuit includes a CPU chip U3 and a capacitor C6; the VDDA pin (pin 5) and the VDD pin (pin 1 and pin 17) of the CPU chip U3 are connected to the VREF pin (pin 1) of the chip U1; the VDDA pin (pin 5) of the CPU chip U3 is also grounded through the capacitor C6; the PA10 pin (pin 20) of the CPU chip U3 is connected to the SDA pin (pin 2) of the infrared temperature measuring probe; the PA9 pin (pin 19) of the CPU chip U3 is connected to the SCL pin (pin 1) of the infrared temperature measuring probe; the RST pin (pin 4), SWDIO pin (pin 23) and SWCLK pin (pin 24) of the CPU chip U3 are connected to empty space; the remaining pins of the CPU chip U3 are all grounded; the VSS pin (pin 4) of the infrared temperature measuring probe is grounded.

[0010] In order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the power supply includes a VIP terminal and a VIN terminal, and the VIP terminal is connected to the V+ pin (pin 7) of the chip U1 through a diode D1, and the VIN terminal is directly connected to the IO pin (pin 4) of the chip U1.

[0011] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0012] (1) The utility model can realize non-contact temperature measurement and has a wide range of application scenarios. It plays an important role in industrial manufacturing, safety monitoring, medical diagnosis, logistics and transportation, etc., and provides a reliable temperature detection method for related industries.

[0013] (2) The utility model adopts 4-20mA analog output, which is a commonly used analog control method. It can convert the sensor signal into a 4-20mA analog signal and transmit it to the remote control system. 4-20mA analog output has good stability, reliability and high precision, so it has been widely used in the field of industrial control.

[0014] (3) The utility model only needs to connect two wires (VIP, VIP). The current on the wires can be detected according to the temperature change, and the wiring is very simple.

[0015] (4) The utility model can effectively combine the advantages of infrared temperature measurement technology and 4-20mA direct current transmission analog quantity, measure the temperature of the object being measured in a non-contact manner, and then output a 4-20mA direct current analog signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a principle block diagram of the utility model.

[0017] Figure 2 This is a typical circuit schematic diagram of the utility model. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the embodiments, but the implementation manner of the present invention is not limited thereto.

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is claimed, but merely represents selected embodiments of the utility model.

[0020] It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. At the same time, in the description of this application, relational terms such as "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone.

[0021] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by terms, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0022] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, "multiple" means two or more, and "multi-bit" means two or more, unless otherwise clearly and specifically defined.

[0023] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] It should be noted that, in some embodiments, the MOS tube or MOSFET in the circuit can be replaced by other transistors that realize similar functions. For example, the MOS tube can be replaced by a bipolar transistor, a silicon carbide (SiC) transistor, a gallium nitride (GaN) transistor, a cubic indium phosphide (InP) transistor, a gallium arsenide (GaAs) transistor, a field effect transistor (Field Effect Transistor, FET), a junction field effect transistor (Junction Field-Effect Transistor, JFET), a heterojunction bipolar transistor (Heterojunction Bipolar Transistor, HBT) or an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT). Therefore, the MOS tube structure in the above example cannot be understood as a limitation to the present application.

[0025] The electronic device may be a device including a circuit or device of a semiconductor device, such as a mobile phone, a computer, a television, a communication device, a communication device, etc. The electronic device provided in the embodiment of the present application has the same implementation principle and technical effects as the following high data flow transmission interface structure circuit embodiment. For the sake of brief description, for any part not mentioned in the electronic device embodiment, reference may be made to the corresponding content in the high data flow transmission interface structure circuit embodiment.

[0026] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0027] Alternatively, the present invention may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the present invention may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part.

[0028] In this article, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, principle, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, principle, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, principle, article or device including the elements.

[0029] Embodiment 1:

[0030] The utility model designs an infrared temperature measuring device with an output of 4-20mA, which has the characteristics of simple structure and convenient wiring. Figure 1 , Figure 2 As shown, it includes a power supply, a voltage conversion circuit, a 4-20mA converter, a CPU circuit and an infrared temperature measuring probe. The power supply is connected to the 4-20mA converter, the 4-20mA converter is respectively connected to the CPU circuit and the voltage conversion circuit, the CPU circuit is connected to the infrared temperature measuring probe, and the voltage conversion circuit is connected to the infrared temperature measuring probe.

[0031] As a preferred design solution, the 4-20mA converter is used to output 5V, and then the 5V is converted into 3.3V through the LDO (chip U4) to power the infrared temperature probe.

[0032] The 4-20mA converter also outputs 2.5v (2v5) to power the CPU chip U3.

[0033] The infrared temperature probe (U2) measures the temperature of the point heat source through infrared.

[0034] The CPU circuit reads the temperature value through I2C and outputs the corresponding voltage value according to the temperature value.

[0035] The 4-20mA converter converts the voltage value output by the CPU circuit into a 4-20mA current signal output.

[0036] After CPU chip U3 reads the temperature data through I2C, it outputs a voltage Vout; chip U1 converts the voltage signal into a current signal and outputs it: Iout=100*(Vout / R1).

[0037] Embodiment 2:

[0038] This embodiment is further optimized on the basis of the above embodiment, and the same points as the above technical solution are not repeated here. Figure 1 , Figure 2 As shown, in order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the 4-20mA converter includes a chip U1, a transistor Q1, a diode D1, a capacitor C1, a capacitor C4, a capacitor C5, a resistor R1 and a resistor R2, the VREG (pin 8) of the chip U1 is connected to the voltage conversion circuit, the VREF pin (pin 1) of the chip U1 is grounded through a resistor R2 and a capacitor C4 connected in series, and the VREF pin (pin 1) of the chip U1 is also grounded through a capacitor C5; the VREF pin (pin 1) of the chip U1 is also connected to the CPU circuit, and the VREF pin (pin 1) of the chip U1 is connected to the CPU circuit. The IN pin (pin 2) is connected to the CPU circuit through the resistor R1; the third end (collector) of the transistor Q1 is connected to the V+ pin (pin 7) of the chip U1, the second end (base) of the transistor Q1 is connected to the Base pin (pin 6) of the chip U1, the first end (emitter) of the transistor Q1 is connected to the Emitter pin (pin 5) of the chip U1, one end of the power supply is connected to the V+ pin (pin 7) of the chip U1 through the diode D1, the other end of the power supply is connected to the IO pin (pin 4) of the chip U1, the capacitor C1 is connected between the V+ pin (pin 7) and the IO pin (pin 4) of the chip U1, and the IRET pin (pin 3) of the chip U1 is grounded.

[0039] Embodiment 3:

[0040] This embodiment is further optimized on the basis of any of the above embodiments, and the same points as the above technical solutions are not repeated here. Figure 1 , Figure 2 As shown, in order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the transistor Q1 adopts a triode, and the first and third ends of the triode are the emitter, the base and the collector respectively; the positive electrode of the diode D1 is connected to the power supply.

[0041] Embodiment 4:

[0042] This embodiment is further optimized on the basis of any of the above embodiments, and the same points as the above technical solutions are not repeated here. Figure 1 , Figure 2As shown, in order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the voltage conversion circuit realizes the function of 5v to 3.3v, including chip U4, capacitor C2 and capacitor C3, the IN pin (pin 3) of chip U4 is connected to 5V DC and grounded through capacitor C2, the IN pin (pin 3) of chip U4 is also connected to the 4-20mA converter (VREG pin of chip U1); the OUT pin (pin 2) of chip U4 is connected to the VDD pin (pin 3) of the infrared temperature measuring probe, and the OUT pin (pin 2) of chip U4 is also grounded through capacitor C3, and the GND pin (pin 1) of chip U4 is grounded.

[0043] Embodiment 5:

[0044] This embodiment is further optimized on the basis of any of the above embodiments, and the same points as the above technical solutions are not repeated here. Figure 1 , Figure 2 As shown, in order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the CPU circuit includes a CPU chip U3 and a capacitor C6, the VDDA pin (pin 5) and the VDD pin (pin 1 and pin 17) of the CPU chip U3 are connected to the VREF pin (pin 1) of the chip U1, and the VDDA pin (pin 5) of the CPU chip U3 is also grounded through the capacitor C6; the PA10 pin (pin 20) of the CPU chip U3 is connected to the SDA pin (pin 2) of the infrared temperature measuring probe, the PA9 pin (pin 19) of the CPU chip U3 is connected to the SCL pin (pin 1) of the infrared temperature measuring probe, the RST pin (pin 4), the SWDIO pin (pin 23) and the SWCLK pin (pin 24) of the CPU chip U3 are connected to empty, and the remaining pins of the CPU chip U3 are all grounded; the VSS pin (pin 4) of the infrared temperature measuring probe is grounded.

[0045] Embodiment 6:

[0046] This embodiment is further optimized on the basis of any of the above embodiments, and the same points as the above technical solutions are not repeated here. Figure 1 , Figure 2 As shown, in order to better realize the infrared temperature measuring device with an output of 4-20mA described in the utility model, the following setting structure is particularly adopted: the power supply includes a VIP terminal and a VIN terminal, and the VIP terminal is connected to the V+ pin (pin 7) of the chip U1 through a diode D1, and the VIN terminal is directly connected to the IO pin (pin 4) of the chip U1.

[0047] Embodiment 7:

[0048] An infrared temperature measuring device with an output of 4-20mA has the characteristics of simple structure and convenient wiring. Figure 1 , Figure 2 Shown, including

[0049] The power supply consists of the VIP terminal and the VIN terminal;

[0050] A 5v to 3.3v voltage conversion circuit composed of chip U4, capacitor C2 and capacitor C3;

[0051] A 4-20mA converter composed of chip U1, transistor Q1, diode D1, capacitor C1, capacitor C4, capacitor C5, resistor R1 and resistor R2;

[0052] The CPU chip U3, capacitor C6 and infrared temperature probe (U2) are composed of the CPU circuit.

[0053] Among them, pin 8 of chip U1 is connected to pin 3 of chip U4, pin 3 of chip U4 is grounded through capacitor C2, pin 1 of chip U1 is grounded through resistor R2 and capacitor C4 connected in series, and pin 1 of chip U1 is also grounded through capacitor C5; pin 1 of chip U1 is also connected to pin 1 of CPU chip U3, and pin 2 of chip U1 is connected to pin 10 of CPU chip U3 through resistor R1; the collector of transistor Q1 is connected to pin 7 of chip U1, the base of transistor Q1 is connected to pin 6 of chip U1, the emitter of transistor Q1 is connected to pin 5 of chip U1, the VIP end of the power supply (connected to the positive pole of diode D1) is connected to pin 7 of chip U1 through diode D1, the VIN of the power supply is connected to pin 4 of chip U1, capacitor C1 is connected between pin 7 and pin 4 of chip U1, and pin 3 of chip U1 is grounded.

[0054] Pin 2 of chip U4 is connected to pin 3 of the infrared temperature probe (U2), pin 2 of chip U4 is also grounded through capacitor C3, and pin 1 of chip U4 is grounded.

[0055] Pins 5, 1 and 17 of the CPU chip U3 are connected in common, and pin 5 of the CPU chip U3 is also grounded through capacitor C6; pin 20 of the CPU chip U3 is connected to pin 2 of the infrared temperature probe (U2), pin 19 of the CPU chip U3 is connected to pin 1 of the infrared temperature probe (U2), pins 4, 23 and 24 of the CPU chip U3 are left empty, pins 25 to 32 of the CPU chip U3 are connected in common and grounded, pins 2 and 3 of the CPU chip U3 are connected in common and grounded, pins 6 to 9 of the CPU chip U3 are connected in common and grounded, pins 11 to 16 of the CPU chip U3 are connected in common and grounded, pin 18 of the CPU chip U3 is grounded, pins 21 and 22 of the CPU chip U3 are connected in common and grounded, and pin 4 of the infrared temperature probe is grounded.

[0056] Preferably, when implementing this embodiment, each component may refer to components with the following parameters.

[0057]

[0058] The 4-20mA converter is used to output 5V, which is then converted into 3.3V through LDO (chip U4) to power the infrared temperature probe.

[0059] The 4-20mA converter also outputs 2.5v (2v5) to power the CPU chip U3.

[0060] The infrared temperature probe (U2) measures the temperature of the point heat source through infrared.

[0061] The CPU circuit reads the temperature value through I2C and outputs the corresponding voltage value according to the temperature value.

[0062] The 4-20mA converter converts the voltage value output by the CPU circuit into a 4-20mA current signal output.

[0063] After CPU chip U3 reads the temperature data through I2C, it outputs a voltage Vout; chip U1 converts the voltage signal into a current signal and outputs it: Iout=100*(Vout / R1).

[0064] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An infrared temperature measuring device with an output of 4-20mA, characterized in that: It includes a power supply, a voltage conversion circuit, a 4-20mA converter, a CPU circuit and an infrared temperature measuring probe. The power supply is connected to the 4-20mA converter, the 4-20mA converter is respectively connected to the CPU circuit and the voltage conversion circuit, the CPU circuit is connected to the infrared temperature measuring probe, and the voltage conversion circuit is connected to the infrared temperature measuring probe.

2. The infrared temperature measuring device with an output of 4-20mA according to claim 1, characterized in that: The 4-20mA converter includes a chip U1, a transistor Q1, a diode D1, a capacitor C1, a capacitor C4, a capacitor C5, a resistor R1 and a resistor R2. The VREG pin of the chip U1 is connected to the voltage conversion circuit, the VREF pin of the chip U1 is grounded through a resistor R2 and a capacitor C4 connected in series, and the VREF pin of the chip U1 is also grounded through a capacitor C5; the VREF pin of the chip U1 is also connected to the CPU circuit, and the IN pin of the chip U1 is connected to the CPU circuit through a resistor R1; the third end of the transistor Q1 is connected to the V+ pin of the chip U1, the second end of the transistor Q1 is connected to the Base pin of the chip U1, the first end of the transistor Q1 is connected to the Emitter pin of the chip U1, one end of the power supply is connected to the V+ pin of the chip U1 through a diode D1, the other end of the power supply is connected to the IO pin of the chip U1, the capacitor C1 is connected between the V+ pin and the IO pin of the chip U1, and the IRET pin of the chip U1 is grounded.

3. The infrared temperature measuring device with an output of 4-20mA according to claim 2, characterized in that: The transistor Q1 is a triode, and the first and third terminals of the triode are the emitter, the base and the collector in sequence; the positive electrode of the diode D1 is connected to the power supply.

4. The infrared temperature measuring device with an output of 4-20mA according to claim 2, characterized in that: The voltage conversion circuit realizes the function of converting 5V to 3.3V, and includes chip U4, capacitor C2 and capacitor C3. The IN pin of chip U4 is connected to 5V DC and grounded through capacitor C2, and the IN pin of chip U4 is connected to the VREG pin of chip U1; the OUT pin of chip U4 is connected to the VDD pin of the infrared temperature measuring probe, and the OUT pin of chip U4 is also grounded through capacitor C3, and the GND pin of chip U4 is grounded.

5. An infrared temperature measuring device with an output of 4-20mA according to claim 2, 3 or 4, characterized in that: The CPU circuit includes a CPU chip U3 and a capacitor C6. The VDDA pin and VDD pin of the CPU chip U3 are connected in common and connected to the VREF pin of the chip U1. The VDDA pin of the CPU chip U3 is also grounded through the capacitor C6; the PA10 pin of the CPU chip U3 is connected to the SDA pin of the infrared temperature probe, the PA9 pin of the CPU chip U3 is connected to the SCL pin of the infrared temperature probe, the RST pin, SWDIO pin and SWCLK pin of the CPU chip U3 are left empty, and the remaining pins of the CPU chip U3 are all grounded; the VSS pin of the infrared temperature probe is grounded.

6. An infrared temperature measuring device with an output of 4-20mA according to claim 2, 3 or 4, characterized in that: The power supply includes a VIP terminal and a VIN terminal, and the VIP terminal is connected to the V+ pin of the chip U1 through a diode D1, and the VIN terminal is directly connected to the IO pin of the chip U1.

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