A V / I conversion circuit based on intelligent reconstruction of an electric valve positioner

Abstract

This utility model discloses a V / I conversion circuit based on the intelligent transformation of an electric valve positioner, including a DAC conversion chip U2, operational amplifier U4B, operational amplifier U4A, and transistor Q1. Pins 8 and 9 of the DAC conversion chip U2 are connected to a microcontroller for receiving data. Pins 5 and 6 of the DAC conversion chip U2 both output voltage data and are connected to pin 5 of the operational amplifier U4B. Pin 7 of the operational amplifier U4B outputs processed voltage data and is connected to pin 3 of the operational amplifier U4A. Pin 1 of the operational amplifier U4A outputs amplified voltage data and is connected to the base of the transistor Q1. The collector of the transistor Q1 outputs the converted current signal to the I / P electrical conversion unit. A capacitor C12 is also provided at the collector of the transistor Q1. This utility model's voltage / current conversion circuit is simple, replacing the original force balance principle, easy to integrate, low in cost, provides a smooth current signal, and improves the positioning accuracy of the electric valve positioner.

Description

Technical Field

[0001] This utility model relates specifically to a V / I conversion circuit based on the intelligent transformation of an electric valve positioner. Background Technology

[0002] An electric valve positioner controls the air intake and exhaust of a pneumatic actuator, driving the valve to a set point. It typically uses an I / P (Inverter-to-Press) electrical conversion unit to convert the current signal into an electrical signal to control the valve opening. The I / P component of the electric valve positioner is its core component. It first receives the electrical signal (4-20mA) from the control system and converts it into electromagnetic force through internal circuitry to control the nozzle back pressure and thus the pneumatic output. In the I / P electrical conversion unit, "I" refers to current and "P" refers to air pressure. Currently, ordinary mechanical electric valve positioners achieve positioning based on the principle of force balance. This results in a complex structure, susceptibility to interference, uneven current signals, and reduced accuracy. Furthermore, it leads to complex debugging, low accuracy, and poor stability. Utility Model Content

[0003] To address the shortcomings of the existing technology, this invention provides a V / I conversion circuit based on the intelligent transformation of an electric valve positioner. This voltage / current conversion circuit is simple, replaces the original force balance principle, is easy to integrate, has low cost, provides a smooth current signal, and improves the positioning accuracy of the electric valve positioner.

[0004] To achieve the above technical objectives, this utility model adopts the following technical solution: a V / I conversion circuit based on the intelligent transformation of an electric valve positioner, including a DAC conversion chip U2, operational amplifier U4B, operational amplifier U4A, and transistor Q1. Pins 8 and 9 of the DAC conversion chip U2 are connected to a microcontroller for receiving data. Pins 5 and 6 of the DAC conversion chip U2 both output voltage data and are connected to pin 5 of the operational amplifier U4B. Pin 7 of the operational amplifier U4B outputs processed voltage data and is connected to pin 3 of the operational amplifier U4A. Pin 1 of the operational amplifier U4A outputs amplified voltage data and is connected to the base of the transistor Q1. The collector of the transistor Q1 outputs the converted current signal to the I / P electrical conversion unit. A capacitor C12 is also provided at the collector of the transistor Q1.

[0005] Pin 8 of the DAC converter chip U2 is connected to pin 15 of the microcontroller, and pin 9 of the DAC converter chip U2 is connected to pin 17 of the microcontroller.

[0006] The DAC converter chip U2 has a resistor R12 connected to pin 5 and a resistor R13 connected to pin 6. Both resistors R12 and R13 are connected to pin 5 of the operational amplifier U4B.

[0007] One of the 6 pins of the operational amplifier U4B is connected to resistor R15, which is connected to pin 7 of the operational amplifier U4B. The other pin is connected to resistor R14, which is grounded.

[0008] Pin 2 of the operational amplifier U4A is connected to resistor R16, resistor R16 is connected to resistor R17, and resistor R17 is grounded; pin 4 of the operational amplifier U4A is grounded; pin 8 of the operational amplifier U4A is connected to capacitor C11, and capacitor C11 is grounded.

[0009] The emitter of transistor Q1 is connected to resistor R17; the collector of transistor Q1 is connected to capacitor C12 and two-core terminal JP_COIL. Capacitor C12 and capacitor C11 are connected to EP+, and the two-core terminal JP_COIL is connected to the I / P electrical conversion unit.

[0010] The DAC conversion chip U2 is model AD5322BRMZ.

[0011] The operational amplifiers U4A and U4B are of the TLV8542DR model.

[0012] The transistor Q1 is of model BCX56-16.

[0013] In summary, this utility model achieves the following technical effects:

[0014] This utility model features a simple voltage / current conversion circuit that replaces the original force balance principle, making it easy to integrate, low in cost, and providing a smooth current signal, thereby improving the positioning accuracy of the electric valve positioner.

[0015] The intelligent control I / P component can detect interferences such as valve stem friction and medium pressure fluctuations in real time, and adjust the output air pressure to overcome unbalanced forces, ensuring accurate valve positioning. Attached Figure Description

[0016] Figure 1 It is a V / I conversion circuit based on the intelligent transformation of electric valve positioners;

[0017] Figure 2 This is a schematic diagram of the product to which this utility model is applied. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings.

[0019] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0020] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] Example:

[0025] Figure 1This is a V / I conversion circuit based on the intelligent transformation of an electric valve positioner. It is applied to an electric valve positioner and includes a DAC conversion chip U2, operational amplifier U4B, operational amplifier U4A, and transistor Q1. Pins 8 and 9 of the DAC conversion chip U2 are connected to a microcontroller for receiving data. Pins 5 and 6 of the DAC conversion chip U2 output voltage data and are connected to pin 5 of operational amplifier U4B. Pin 7 of operational amplifier U4B outputs processed voltage data and is connected to pin 3 of operational amplifier U4A. Pin 1 of operational amplifier U4A outputs amplified voltage data and is connected to the base of transistor Q1. The collector of transistor Q1 outputs the converted current signal to the I / P electrical conversion unit. The collector of transistor Q1 is also equipped with a capacitor C12.

[0026] The V / I conversion circuit of this application converts the voltage signal into a current signal and outputs the current signal to the I / P electrical conversion unit. The I / P electrical conversion unit then processes the current signal to regulate the valve.

[0027] Pin 8 of DAC converter chip U2 is connected to pin 15 of the microcontroller, and pin 9 of DAC converter chip U2 is connected to pin 17 of the microcontroller. Pin 5 of DAC converter chip U2 is connected to resistor R12, and pin 6 of DAC converter chip U2 is connected to resistor R13. Resistors R12 and R13 are both connected to pin 5 of op-amp U4B.

[0028] The control software detects valve position data through the valve position detection unit, compares the set position data sampled from the input signal, calculates the difference, and sends the corresponding data to pins 8 and 9 of U2 through the SPI port (pins 15 and 17 for synchronous serial communication) of the microcontroller (not shown), thereby outputting voltage data through pins 5 and 6 of U2.

[0029] The DAC converter chip U2 uses the AD5322BRMZ dual-channel 12-bit voltage output DAC chip.

[0030] Pin 6 of op-amp U4B is connected to resistor R15 on one side, which is connected to pin 7 of op-amp U4B on the other side. Resistor R14 is grounded.

[0031] Pin 2 of op-amp U4A is connected to resistor R16, which is connected to resistor R17, and resistor R17 is grounded; pin 4 of op-amp U4A is grounded; pin 8 of op-amp U4A is connected to capacitor C11, and capacitor C11 is grounded.

[0032] Op-amps U4B and U4A are the same op-amp, using the TLV8542DR model, and are used for voltage summing and amplification.

[0033] The emitter of transistor Q1 is connected to resistor R17; the collector of transistor Q1 is connected to capacitor C12 and two-core terminal JP_COIL. Capacitor C12 and capacitor C11 are connected to EP+. The two-core terminal JP_COIL is connected to the I / P electrical conversion unit.

[0034] Transistor Q1 is of model BCX56-16.

[0035] Pins 5 and 6 of U2 output two voltages, which are then converted into current by an operational amplifier circuit U4 and a V / I conversion circuit composed of resistors R12, R13, R14, R15, R16, R17 and transistor Q1. To further explain, the voltage values ​​generated at pins 5 and 6 of U2 are added by an operational amplifier circuit composed of U4B, and the combined voltage is supplied to pin 3 of another operational amplifier U4A via pin 7. U4A and transistor Q1 convert this voltage signal into a current signal, which is then supplied to the I / P electrical conversion unit connected to the two-pin terminal JP_COIL. Capacitor C12 is a filter capacitor to ensure a smooth and clean output current signal. The I / P electrical conversion unit can control air pressure changes according to different current magnitudes, controlling the valve to move to a designated position and achieving precise valve positioning.

[0036] This application's U2 outputs two voltage channels, which meets the requirements for the intelligent transformation of mechanical positioners.

[0037] Figure 2 This is a schematic diagram of the product to which this utility model is applied. It includes a main board 1, which contains all the control components for the intelligent transformation of the electric valve positioner. The V / I conversion circuit of this application is also integrated on this main board. Two support pillars 3 are fixed on the main board, as is a mounting plate 2, which is fixed to the support pillars 3. An LCD display screen 4 and three buttons 8 are fixed on the mounting plate. The main board 1 also has multiple terminal blocks 5, 6, and 7, as well as buttons 9.

[0038] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the scope of the technical solution of the present utility model.

Claims

1. A V / I conversion circuit based on intelligent retrofit of an electric valve positioner, characterized by: The system includes a DAC converter chip U2, operational amplifier U4B, operational amplifier U4A, and transistor Q1. Pins 8 and 9 of the DAC converter chip U2 are connected to a microcontroller for receiving data. Pins 5 and 6 of the DAC converter chip U2 both output voltage data and are connected to pin 5 of the operational amplifier U4B. Pin 7 of the operational amplifier U4B outputs processed voltage data and is connected to pin 3 of the operational amplifier U4A. Pin 1 of the operational amplifier U4A outputs amplified voltage data and is connected to the base of the transistor Q1. The collector of the transistor Q1 outputs a converted current signal to the I / P electrical conversion unit. A capacitor C12 is also provided at the collector of the transistor Q1.

2. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 1, characterized in that Pin 8 of the DAC converter chip U2 is connected to pin 15 of the microcontroller, and pin 9 of the DAC converter chip U2 is connected to pin 17 of the microcontroller.

3. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 1, characterized in that: The DAC converter chip U2 has a resistor R12 connected to pin 5 and a resistor R13 connected to pin 6. Both resistors R12 and R13 are connected to pin 5 of the operational amplifier U4B.

4. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 3, characterized in that: One of the 6 pins of the operational amplifier U4B is connected to resistor R15, which is connected to pin 7 of the operational amplifier U4B. The other pin is connected to resistor R14, which is grounded.

5. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 1, characterized in that: Pin 2 of the operational amplifier U4A is connected to resistor R16, resistor R16 is connected to resistor R17, and resistor R17 is grounded; pin 4 of the operational amplifier U4A is grounded; pin 8 of the operational amplifier U4A is connected to capacitor C11, and capacitor C11 is grounded.

6. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 1, characterized in that: The emitter of transistor Q1 is connected to resistor R17; the collector of transistor Q1 is connected to capacitor C12 and two-core terminal JP_COIL. Capacitor C12 and capacitor C11 are connected to EP+, and the two-core terminal JP_COIL is connected to the I / P electrical conversion unit.

7. The V / I conversion circuit based on the intelligent transformation of an electric valve positioner according to claim 1, characterized in that: The DAC conversion chip U2 is model AD5322BRMZ.

8. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 1, characterized in that: The operational amplifiers U4A and U4B are of the TLV8542DR model.

9. The V / I conversion circuit based on intelligent reconstruction of an electric valve positioner according to claim 1, characterized in that: The transistor Q1 is of model BCX56-16.

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