Circuit for converting 0-5V control voltage based on 4-20MA analog quantity

Abstract

The utility model discloses a circuit based on 4-20MA analog quantity conversion 0-5V control voltage, and relates to the technical field of electronic ballasts. The circuit based on 4-20MA analog quantity conversion 0-5V control voltage comprises a current-voltage conversion module, a signal processing module and an output control module, and the current-voltage conversion module is connected with the output end of 4-20MA analog quantity and used for converting a current signal of the 4-20MA analog quantity into a voltage signal; the signal processing module is connected with the current-voltage conversion module and is used for processing an input voltage signal, and the output control module is connected with the output end of the signal processing module and is used for outputting 0-5V control voltage. The circuit based on 4-20MA analog quantity conversion 0-5V control voltage provided by the utility model is used for meeting the requirement of accurate control of an electronic ballast.

Description

Technical Field

[0001] This utility model relates to the field of electronic ballast technology, and in particular to a circuit based on 4-20mA analog quantity to 0-5V control voltage conversion. Background Technology

[0002] In the application scenarios of electronic ballasts for ultraviolet electronic ballasts and other gas discharge lamps, there are many problems. On the one hand, the operating environment is often quite harsh, which makes it extremely inconvenient to observe the working status of the light source. On the other hand, when it is necessary to remotely control the working status of the ultraviolet electronic ballast, it is necessary to use the 4-20mA analog signal commonly used in industrial control to control the working status of the electronic ballast. For example, by adjusting the output lamp current of the electronic ballast through the 4-20mA analog signal, the irradiance of the light source can be adjusted.

[0003] Currently, the traditional solution utilizes the frequency control interface circuitry within the dedicated electronic ballast chip. However, this traditional approach has significant drawbacks. Commonly used dedicated electronic ballast chips are mostly analog circuits, exhibiting poor performance in terms of matching and flexibility, inconsistent across different products, and complex peripheral circuitry. This not only increases production costs but also reduces system stability and reliability. Summary of the Invention

[0004] The purpose of this invention is to provide a circuit based on 4-20mA analog-to-0-5V control voltage conversion to meet the requirements for precise control of electronic ballasts.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A circuit based on 4-20mA analog-to-0-5V control voltage conversion includes:

[0007] A current-to-voltage conversion module is connected to the output terminal of a 4-20mA analog DC1 signal and is used to convert the current signal of the 4-20mA analog DC1 signal into a voltage signal.

[0008] A signal processing module, connected to the current-to-voltage conversion module, is used to process the input voltage signal;

[0009] The output control module is connected to the output terminal of the signal processing module and is used to output a 0-5V control voltage.

[0010] Optionally, the current-to-voltage conversion module includes a first resistor R1, a second resistor R2, and a third resistor R3, which are connected in parallel.

[0011] Optionally, the signal processing module includes a filtering module, which includes a first capacitor C1, a second capacitor C2, and a fourth resistor R4 connected to the output terminal of the current-to-voltage conversion module, for filtering the voltage signal.

[0012] Optionally, the signal processing module further includes a dual operational amplifier module, which includes a first operational amplifier A1 and a second operational amplifier A2. The first operational amplifier A1 and the second operational amplifier A2 are configured as voltage followers. The input terminal of the first operational amplifier A1 is connected to the output terminal of the current-to-voltage conversion module through the fourth resistor R4, and the output terminal of the first operational amplifier A1 is connected to the input terminal of the second operational amplifier A2 through the fifth resistor R5.

[0013] Optionally, the signal processing module further includes an optocoupler U1, the input terminal of which is connected to the output terminal of the second operational amplifier A2 via a sixth resistor R6.

[0014] Optionally, the output control module includes a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9 connected to the output terminal of the optocoupler U1, for outputting a DC voltage of 0-5V.

[0015] Compared with existing technologies, this invention adopts a dual operational amplifier module and optocoupler isolation design, which, compared with traditional dedicated chip analog circuits for electronic ballasts, can better adapt to different application scenarios and control requirements. The characteristics of the operational amplifier chip and optocoupler make the circuit easier to integrate with other devices or systems. Only appropriate adjustments to relevant parameters are needed to meet different control requirements, greatly improving the system's versatility and flexibility. Furthermore, through standardized circuit design and parameter adjustment, the solution of this invention can ensure performance consistency between different products. In large-scale production, it can effectively reduce product performance differences, improve product quality stability, and reduce debugging costs and quality control difficulties during production. Moreover, it simplifies the peripheral circuit: the circuit structure of this invention is relatively simple, reducing the number and complexity of electronic components. Compared with traditional solutions, the simplification of the peripheral circuit not only reduces the difficulty and cost of circuit design but also improves the reliability and stability of the system. Due to the reduced number of components, the probability of failure is correspondingly reduced, thereby reducing maintenance costs and repair time. Attached Figure Description

[0016] The accompanying drawings, which are provided to further illustrate the present invention and constitute a part of the present invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention.

[0017] Figure 1 The circuit schematic diagram provided for the embodiments of this utility model.

[0018] Figure label:

[0019] 1-Current-to-voltage conversion module; 2-Signal processing module; 3-Output control module. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present 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 indicated technical features. 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. "Several" means one or more, unless otherwise explicitly specified.

[0022] Please see Figure 1 The circuit based on the conversion of a 4-20mA analog signal to a 0-5V control voltage provided in this embodiment of the invention includes a current-to-voltage conversion module 1, a signal processing module 2, and an output control module 3. The current-to-voltage conversion module 1 is connected to the output terminal of the 4-20mA analog signal DC1 and is used to convert the current signal of the 4-20mA analog signal DC1 into a voltage signal. The signal processing module 2 is connected to the current-to-voltage conversion module 1 and is used to process the input voltage signal. The output control module 3 is connected to the output terminal of the signal processing module 2 and is used to output a 0-5V control voltage.

[0023] In this application, the current-voltage module includes a first resistor R1, a second resistor R2, and a third resistor R3, which are connected in parallel.

[0024] The signal processing module 2 includes a filtering module, a dual operational amplifier module, and an optocoupler U1. Specifically, the filtering module includes a first capacitor C1, a second capacitor C2, and a fourth resistor R4 connected to the output of the current-to-voltage conversion module 1, used for filtering the voltage signal. The dual operational amplifier module includes a first operational amplifier A1 and a second operational amplifier A2, configured as voltage followers. The input of the first operational amplifier A1 is connected to the output of the current-to-voltage conversion module 1 via the fourth resistor R4, and the output of the first operational amplifier A1 is connected to the input of the second operational amplifier A2 via the fifth resistor R5. The input of the optocoupler U1 is connected to the output of the second operational amplifier A2 via the sixth resistor R6.

[0025] In this application, the output control module 3 includes a seventh resistor R7, an eighth resistor R8, and a ninth resistor R9 connected to the output terminal of the optocoupler U1, for outputting a DC voltage of 0-5V.

[0026] In this application, a dual operational amplifier module is used to complete the voltage conversion of 4-20mA analog current; an optocoupler is used to achieve isolated voltage conversion.

[0027] The specific circuit connection is as follows: DC1 is a 4-20mA analog signal commonly used in industrial control. This current signal flows through three resistors connected in parallel: the first resistor R1, the second resistor R2, and the third resistor R3 (actually three 250-ohm resistors in parallel). According to the parallel resistance calculation formula, the parallel resistance is 750 ohms. Through this 750-ohm resistor, a voltage signal that changes synchronously with the 4-20mA analog current is obtained. This voltage signal is first filtered by the first capacitor C1 to remove high-frequency noise, and then further filtered by the filter circuit composed of the fourth resistor R4 and the second capacitor C2 before entering the first operational amplifier A1. The first operational amplifier A1 is set as a voltage follower. The characteristic of a voltage follower is that the input voltage and the output voltage are equal. Its function is to improve the driving capability of the input signal and reduce the attenuation during signal transmission. The output voltage of the first operational amplifier A1 passes through the fifth resistor R5 and enters the second operational amplifier A2. The second operational amplifier A2 is also configured as a voltage follower, further buffering and amplifying the signal. The output voltage is filtered by the third capacitor C3 and driven by the sixth resistor R6 to drive the optocoupler U1. The optocoupler U1 provides electrical isolation, ensuring that its secondary impedance follows the 4-20mA current variation. The secondary winding of the optocoupler passes through an impedance matching network composed of the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9. By adjusting the parameters (shown in the diagram), a 0-5V DC voltage that synchronously changes with the 4-20mA current can be obtained. This voltage is then output to other subsequent circuits for processing, providing a stable and reliable control signal for controlling the operation of the electronic ballast.

[0028] As can be seen from the structure of the circuit based on the 4-20mA analog-to-0-5V control voltage conversion described above, this invention adopts a dual operational amplifier module and optocoupler isolation design, which, compared to traditional dedicated analog circuits for electronic ballasts, can better adapt to different application scenarios and control requirements. The characteristics of the operational amplifier chip and optocoupler make the circuit easier to integrate with other devices or systems; only appropriate adjustments to relevant parameters are needed to meet different control requirements, greatly improving the system's versatility and flexibility. Furthermore, through standardized circuit design and parameter adjustment, the solution of this invention can ensure performance consistency between different products. In large-scale production, it can effectively reduce product performance differences, improve product quality stability, and reduce debugging costs and quality control difficulties during production. Moreover, it simplifies the peripheral circuit: the circuit structure of this invention is relatively simple, reducing the number and complexity of electronic components. Compared to traditional solutions, the simplification of the peripheral circuit not only reduces the difficulty and cost of circuit design but also improves the reliability and stability of the system. Due to the reduced number of components, the probability of failure is correspondingly reduced, thereby reducing maintenance costs and repair time.

[0029] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0030] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A circuit for converting 4-20MA analog quantity into 0-5V control voltage, characterized in that, The utility model relates to a 4-20MA analog quantity DC1 current-voltage conversion circuit, comprising: a current-voltage conversion module connected to the output end of 4-20MA analog quantity DC1 for converting the current signal of 4-20MA analog quantity DC1 into a voltage signal; a signal processing module connected to the current-voltage conversion module for processing the input voltage signal; an output control module connected to the output end of the signal processing module for outputting a 0-5V control voltage.

2. The circuit for converting 4-20 mA analog quantity into 0-5 V control voltage according to claim 1, characterized in that, The current-voltage conversion module comprises a first resistor R1, a second resistor R2 and a third resistor R3 connected in parallel.

3. The circuit for converting 4-20 mA analog quantity into 0-5 V control voltage according to claim 1, characterized in that, The signal processing module comprises a filter module comprising a first capacitor C1, a second capacitor C2 and a fourth resistor R4 connected to the output end of the current-voltage conversion module for filtering the voltage signal.

4. The circuit for converting 4-20 mA analog quantity into 0-5 V control voltage according to claim 3, characterized in that, The signal processing module further comprises a double operational amplifier module comprising a first operational amplifier A1 and a second operational amplifier A2 configured as a voltage follower, the input end of the first operational amplifier A1 being connected to the output end of the current-voltage conversion module through the fourth resistor R4, and the output end of the first operational amplifier A1 being connected to the input end of the second operational amplifier A2 through a fifth resistor R5.

5. The circuit for converting 4-20 mA analog quantity into 0-5 V control voltage according to claim 4, characterized in that, The signal processing module further comprises an optoelectronic coupler U1, the input end of the optoelectronic coupler U1 being connected to the output end of the second operational amplifier A2 through a sixth resistor R6.

6. The circuit for converting 4-20 mA analog quantity into 0-5 V control voltage according to claim 5, characterized in that, The output control module comprises a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9 connected to the output end of the optoelectronic coupler U1 for outputting a 0-5V direct current voltage.

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