A circuit for current signal long line transmission data processing

Abstract

The application relates to the technical field of data transmission, in particular to a circuit for current signal long-line transmission data processing. The circuit comprises an isolation power supply, a first module, a sampling resistor R1, a second module and a third module; the first module is used for data acquisition, coding and modulation into a current signal; the second module is used for voltage signal processing and outputs the processed voltage signal to the third module; the third module is used for voltage signal decoding, storage and display; the isolation power supply, the first module and the sampling resistor R1 are sequentially and in series connected on a dry line; the second module is connected in parallel with the sampling resistor R1; the sampling resistor R1 is indirectly connected with the first module; the second module comprises a capacitor C0, an operational amplifier circuit and a second-order low-pass filter circuit; the capacitor C0 is connected in parallel with the sampling resistor R1; the operational amplifier circuit and the second-order low-pass filter circuit are connected in series and then connected in parallel with the sampling resistor R1; the output end of the second-order low-pass filter circuit is connected with the third module, so that signal filtering and noise reduction are realized.

Description

Technical Field

[0001] This application relates to the field of data transmission technology, and in particular to a circuit for long-line transmission data processing of current signals. Background Technology

[0002] Currently, in many industrial fields, milliampere-level current signals are used as variables for various sensors, or the changes in milliampere-level current are controlled by coding rules to transmit multiple sets of data over long distances. However, due to the large number of power devices in industrial environments, interference is easily introduced, especially harmonics and surges from devices such as frequency converters and servo drives. In addition, when the application scenario is special, conventional methods such as separate wiring and the use of shielded wires cannot be used, resulting in signal fluctuations and decreased accuracy. Consequently, the decoding program cannot effectively identify changes in current and cannot decode the data.

[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Utility Model Content

[0004] The purpose of this application is to provide a circuit for long-line transmission of current signals and data processing, so as to solve or alleviate the problems existing in the prior art.

[0005] To achieve the above objectives, this application provides the following technical solution: A circuit for long-line transmission data processing of current signals, the circuit comprising an isolation power supply, a first module, a sampling resistor R1, a second module, and a third module; The first module is used for data acquisition, encoding, and modulation into a current signal; the second module is used for voltage signal processing and outputting the processed voltage signal to the third module; the third module is used for voltage signal decoding, storage, and display. The isolation power supply, the first module, and the sampling resistor R1 are connected in series on the main circuit; the second module and the sampling resistor R1 are connected in parallel; the sampling resistor R1 and the first module are connected indirectly. The second module includes capacitor C0, operational amplifier circuit, and second-order low-pass filter circuit; The capacitor C0 is connected in parallel with the sampling resistor R1; the operational amplifier circuit and the second-order low-pass filter circuit are connected in series, and then connected in parallel with the sampling resistor R1; the output of the second-order low-pass filter circuit is connected to the third module.

[0006] Preferably, the second module further includes an independently configured first-order low-pass filter circuit; The output of the second-order low-pass filter circuit is connected to the independently configured first-order low-pass filter circuit, and the output of the independently configured first-order low-pass filter circuit is connected to the third module.

[0007] Preferably, the operational amplifier circuit is connected in series with multiple second-order low-pass filter circuits.

[0008] Preferably, the non-inverting input terminal of the operational amplifier in the operational amplifier circuit is grounded through an adjustable resistor R4.

[0009] Preferably, after the positive and negative power supply terminals of the operational amplifiers in the operational amplifier circuit and the second-order low-pass filter circuit are powered on, they are both grounded through capacitors.

[0010] Preferably, in the final second-order low-pass filter circuit, multiple capacitors are connected in parallel and grounded in the first-order low-pass filter circuit.

[0011] Preferably, the first module includes a data acquisition and encoding module, a current-limiting resistor R21, and a transistor N1; The collector of transistor N1 is connected to current-limiting resistor R21, the emitter is connected to the negative power supply terminal of the data acquisition and encoding module, and the base is connected to the output terminal of the data acquisition and encoding module; the other end of current-limiting resistor R21 is connected to the positive power supply terminal of the data acquisition and encoding module. The data acquisition and encoding module outputs a PWM signal to control the transistor N1 to turn on and off.

[0012] Preferably, the first module further includes a resistor R20; the output terminal of the data acquisition and encoding module is also grounded through the resistor R20.

[0013] Compared with the closest prior art, the technical solution of this application has the following beneficial effects: This application uses the first module to complete data acquisition and encoding, and modulates it into a current signal. Then, it is converted into a voltage signal through the sampling resistor R1. After being filtered by capacitor C0, amplified by an operational amplifier circuit, and filtered again by a second-order low-pass filter circuit, it is output to the third module, effectively realizing the noise reduction processing of the voltage signal. Attached Figure Description

[0014] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 The circuit structure diagrams provided according to some embodiments of this application are shown.

[0015] Explanation of reference numerals in the attached figures: 1. Isolated power supply; 2. Third module; 3. Data acquisition and encoding module. Detailed Implementation

[0016] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0017] In the following description, the terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.

[0019] In the description of this application, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and do not require that this application be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. The terms "connected," "linked," and "set up" used in this application should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; direct connections or indirect connections through intermediate components; wired connections, radio connections, or wireless communication signal connections. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0020] The following will be combined with the appendix Figure 1 A circuit for long-line transmission data processing of current signals according to this application will be described in further detail.

[0021] A circuit for long-line transmission data processing of current signals, the circuit includes an isolation power supply 1, a first module, a sampling resistor R1, a second module, and a third module 2; The first module is used for data acquisition, encoding, and modulation into a current signal; the second module is used for voltage signal processing and outputting the processed voltage signal to the third module 2; the third module 2 is used for voltage signal decoding, storage, and display. The isolation power supply 1, the first module, and the sampling resistor R1 are connected in series on the main circuit; the second module is connected in parallel with the sampling resistor R1; and the sampling resistor R1 is connected indirectly with the first module. The second module includes capacitor C0, operational amplifier circuit, and second-order low-pass filter circuit; Capacitor C0 is connected in parallel with sampling resistor R1; the operational amplifier circuit and the second-order low-pass filter circuit are connected in series, and then connected in parallel with sampling resistor R1; the output of the second-order low-pass filter circuit is connected to the third module 2.

[0022] In a specific embodiment of this application, the main circuit current flows out from the positive power supply terminal of isolation power supply 1, flows sequentially through the first module and sampling resistor R1, and then flows back to the negative power supply terminal of isolation power supply 1; the operational amplifier circuit is specifically an inverting proportional operational amplifier circuit, including resistor R2, resistor R3, and operational amplifier U1. One end of resistor R2 is connected to the negative power supply terminal of isolation power supply 1, and the other end is connected to the inverting input terminal of operational amplifier U1. The inverting input terminal of operational amplifier U1 is also directly connected to the output terminal of operational amplifier U1 through resistor R3, and the non-inverting input terminal of operational amplifier U1 is grounded; the second-order low-pass filter circuit is specifically an inverting... A second-order low-pass filter circuit includes resistors R7, R8, and R9, capacitors C15 and C20, and operational amplifier U2. Resistor R7 and capacitor C15 form a first-order low-pass filter circuit. Resistor R7 is connected to the output of the operational amplifier circuit, and capacitor C15 is grounded. The output of this first-order low-pass filter circuit is connected to the inverting input and output of operational amplifier U2 through resistors R8 and R9, respectively. The inverting input of operational amplifier U2 is also directly connected to the output of operational amplifier U2 through capacitor C20. The non-inverting input of operational amplifier U2 is grounded.

[0023] By adjusting the values ​​of resistors R2 and R3, the voltage signal can be amplified to the required voltage range of the AD conversion input port of the third module 2, that is, the voltage range that the AD conversion input port of the third module 2 can receive and recognize. The third module 2 can use ARM / DSP / MCU chips, etc. Different manufacturers, series and models of ARM / DSP / MCU chips have different power supply voltages, and the requirements of the corresponding AD conversion input port are different, generally 1.8V / 3.3V / 5V, etc.

[0024] After the first module completes data acquisition and encoding, it modulates the data into a current signal. This current signal flows through the sampling resistor R1 and is then converted into a voltage signal. Since the sampling resistor R1 is indirectly connected to the first module, the potential V at the end of the sampling resistor R1 furthest from the first module is... aThis can be considered as a voltage signal converted from a current signal. The voltage signal is first filtered by capacitor C0, then amplified by the operational amplifier circuit to the required voltage range of the third module 2, and finally filtered by a second-order low-pass filter circuit to output a potential V. Data To the third module 2.

[0025] The second module also includes an independently configured first-order low-pass filter circuit; The output of the second-order low-pass filter circuit is connected to an independently configured first-order low-pass filter circuit, and the output of the independently configured first-order low-pass filter circuit is connected to the third module 2.

[0026] In a specific embodiment of this application, the independently configured first-order low-pass filter circuit includes a resistor R19 and a capacitor C13. Resistor R19 is connected to the output terminal of the second-order low-pass filter circuit, and capacitor C13 is grounded; voltage signal V a After being filtered by a second-order low-pass filter circuit, the signal undergoes final filtering by a separately configured first-order low-pass filter circuit to further reduce voltage signal noise. The voltage signal V is then output from the output of this separately configured first-order low-pass filter circuit. Data To the third module 2.

[0027] The operational amplifier circuit is connected in series with multiple second-order low-pass filter circuits.

[0028] In specific embodiments of this application, the second-order low-pass filter circuits are all inverting second-order low-pass filter circuits, and the operational amplifier circuit is connected in series with four second-order low-pass filter circuits in sequence; except for the first second-order low-pass filter circuit composed of resistors R7, R8, R9, capacitors C15, C20, and operational amplifier U2, the second second-order low-pass filter circuit includes resistors R10, R11, R12, capacitors C16, C21, and operational amplifier U3, wherein resistors R10 and C16 form a first-order low-pass filter circuit, and resistor R10... The first second-order low-pass filter circuit is connected to its output. Capacitor C16 is grounded. The output of this first-order low-pass filter circuit is connected to the inverting input and output of operational amplifier U3 via resistors R11 and R12, respectively. The inverting input of operational amplifier U3 is also directly connected to its output via capacitor R21. The non-inverting input of operational amplifier U3 is grounded. The third second-order low-pass filter circuit includes resistors R13, R14, and R15, capacitors C17 and C22, and operational amplifier U4. Resistor R13 and capacitor C17 form a first-order low-pass filter circuit. Resistor R13 is connected to the output of the second second-order low-pass filter circuit, and capacitor C17 is grounded. The output of this first-order low-pass filter circuit is connected to the inverting input and output of operational amplifier U4 via resistors R14 and R15, respectively. The inverting input of operational amplifier U4 is also directly connected to the output of operational amplifier U4 via capacitor R22. The non-inverting input of operational amplifier U4 is grounded. The fourth second-order low-pass filter circuit includes resistors R16, R17, and R18. R18, C18, C24, and operational amplifier U5 are connected. Resistor R16 and capacitor C18 form a first-order low-pass filter circuit. Resistor R16 is connected to the output of a third second-order low-pass filter circuit. Capacitor C18 is grounded. The output of this first-order low-pass filter circuit is connected to the inverting input and output of operational amplifier U5 through resistors R17 and R18, respectively. The inverting input of operational amplifier U5 is also directly connected to the output of operational amplifier U5 through capacitor R24. The non-inverting input of operational amplifier U5 is grounded.

[0029] By setting up multiple second-order low-pass filter circuits and adjusting the values ​​of resistors and capacitors in these circuits according to the voltage signal noise, multi-stage filtering of the amplified voltage signal can be achieved.

[0030] The non-inverting input of the operational amplifier in the operational amplifier circuit is grounded through an adjustable resistor R4 to adjust the bias voltage of the operational amplifier and ensure that the voltage signal is amplified normally.

[0031] After the positive and negative power supply terminals of the operational amplifiers in the operational amplifier circuit and the second-order low-pass filter circuit are connected to the power supply, they are grounded through capacitors to filter out power supply noise.

[0032] In specific embodiments of this application, after the positive and negative power supply terminals of operational amplifier U1 are powered on, they are grounded through capacitors C1 and C2, respectively; after the positive and negative power supply terminals of operational amplifier U2 are powered on, they are grounded through capacitors C3 and C4, respectively; after the positive and negative power supply terminals of operational amplifier U3 are powered on, they are grounded through capacitors C5 and C6, respectively; after the positive and negative power supply terminals of operational amplifier U4 are powered on, they are grounded through capacitors C7 and C8, respectively; and after the positive and negative power supply terminals of operational amplifier U5 are powered on, they are grounded through capacitors C9 and C10, respectively.

[0033] In the final second-order low-pass filter circuit, multiple capacitors are connected in parallel to ground in the first-order low-pass filter circuit.

[0034] In a specific embodiment of this application, the last second-order low-pass filter circuit is the fourth second-order low-pass filter circuit. The first-order low-pass filter circuit in the fourth second-order low-pass filter circuit also includes capacitors C19 and C23. Capacitors C19 and C23 are respectively connected in parallel with capacitor C18 to filter out noise in different frequency bands.

[0035] The first module includes data acquisition and encoding module 3, current limiting resistor R21, and transistor N1; The collector of transistor N1 is connected to the current-limiting resistor R21, the emitter is connected to the negative power supply terminal of data acquisition and encoding module 3, and the base is connected to the output terminal of data acquisition and encoding module 3; the other end of the current-limiting resistor R21 is connected to the positive power supply terminal of data acquisition and encoding module 3. The data acquisition and encoding module 3 outputs a PWM signal to control the transistor N1 to turn on and off.

[0036] In a specific embodiment of this application, the emitter of transistor N1 and the negative power supply terminal of data acquisition and encoding module 3 are grounded; data acquisition and encoding module 3 can use chips such as ARM / DSP / MCU; a I represents the main circuit current flowing through the sampling resistor R1. b I represents the branch current flowing through data acquisition and encoding module 3. c This represents the branch current flowing through the current-limiting resistor R21 and transistor N1; the data acquisition and encoding module 3 outputs a PWM signal, and when the output terminal of the data acquisition and encoding module 3 is high, transistor N1 is turned on, I c ≠0, I a =I b +Ic When the output of the control data acquisition and encoding module 3 is low, transistor N1 is turned off, and I c =0, I a =I b ;I c The magnitude of the current is determined by the resistance value of R21 and the voltage of the isolation power supply 1. The time when the current is equal to zero and not equal to zero is determined by the encoding method of the data acquisition and encoding module 3.

[0037] The first module also includes a resistor R20; the output of the data acquisition and encoding module 3 is also grounded through a resistor R20.

[0038] In a specific embodiment of this application, since the emitter of transistor N1 is grounded, the output terminal of the data acquisition and encoding module 3 is connected to the emitter of transistor N1 through resistor R20. Resistor R20 is the base-to-ground resistance of transistor N1, and its function is to ensure that the base voltage is 0V under uncertain conditions. For example, during the power-on process, the chip pin of the data acquisition and encoding module 3 is in a high-impedance state (disconnected), and the base lead of transistor N1 is essentially floating. At this time, resistor R20 ensures that the base voltage is 0V, thereby turning off transistor N1.

[0039] A processing method for a circuit used for long-line transmission of current signals, comprising: Step S1: The first module acquires and encodes data, and modulates it into a current signal; Step S2: The sampling resistor R1 acquires the current signal and converts it into a voltage signal; Step S3: First, the voltage signal is filtered by capacitor C0, and then amplified by the operational amplifier circuit to the required voltage range of the third module 2. Then, it is processed by the second-order low-pass filter circuit and finally output to the third module 2.

[0040] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A circuit for long-line transmission and data processing of current signals, characterized in that, The circuit includes an isolated power supply, a first module, a sampling resistor R1, a second module, and a third module; The first module is used for data acquisition, encoding, and modulation into a current signal; the second module is used for voltage signal processing and outputting the processed voltage signal to the third module; the third module is used for voltage signal decoding, storage, and display. The isolation power supply, the first module, and the sampling resistor R1 are connected in series on the main circuit; the second module and the sampling resistor R1 are connected in parallel; the sampling resistor R1 and the first module are connected indirectly. The second module includes capacitor C0, operational amplifier circuit, and second-order low-pass filter circuit; The capacitor C0 is connected in parallel with the sampling resistor R1; the operational amplifier circuit and the second-order low-pass filter circuit are connected in series, and then connected in parallel with the sampling resistor R1; the output of the second-order low-pass filter circuit is connected to the third module.

2. The circuit for long-line transmission data processing of current signals as described in claim 1, characterized in that, The second module also includes an independently configured first-order low-pass filter circuit; The output of the second-order low-pass filter circuit is connected to the independently configured first-order low-pass filter circuit, and the output of the independently configured first-order low-pass filter circuit is connected to the third module.

3. The circuit for long-line transmission data processing of current signals as described in claim 1, characterized in that, The operational amplifier circuit is connected in series with multiple second-order low-pass filter circuits.

4. The circuit for long-line transmission data processing of current signals as described in claim 1, characterized in that, The non-inverting input terminal of the operational amplifier in the operational amplifier circuit is grounded through an adjustable resistor R4.

5. The circuit for long-line transmission data processing of current signals as described in claim 1, characterized in that, The positive and negative power supply terminals of the operational amplifiers in the operational amplifier circuit and the second-order low-pass filter circuit are grounded through capacitors after being powered on.

6. The circuit for long-line transmission data processing of current signals as described in claim 3, characterized in that, In the final second-order low-pass filter circuit, multiple capacitors are connected in parallel to ground in the first-order low-pass filter circuit.

7. The circuit for long-line transmission data processing of current signals as described in claim 1, characterized in that, The first module includes a data acquisition and encoding module, a current-limiting resistor R21, and a transistor N1; The collector of transistor N1 is connected to current-limiting resistor R21, the emitter is connected to the negative power supply terminal of the data acquisition and encoding module, and the base is connected to the output terminal of the data acquisition and encoding module; the other end of current-limiting resistor R21 is connected to the positive power supply terminal of the data acquisition and encoding module. The data acquisition and encoding module outputs a PWM signal to control the transistor N1 to turn on and off.

8. The circuit for long-line transmission data processing of current signals as described in claim 7, characterized in that, The first module also includes a resistor R20; the output terminal of the data acquisition and encoding module is also grounded through the resistor R20.

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