CN102346464A - 0-20mA or 4-20mA direct current analog quantity output device - Google Patents
0-20mA or 4-20mA direct current analog quantity output device Download PDFInfo
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- CN102346464A CN102346464A CN2011101584340A CN201110158434A CN102346464A CN 102346464 A CN102346464 A CN 102346464A CN 2011101584340 A CN2011101584340 A CN 2011101584340A CN 201110158434 A CN201110158434 A CN 201110158434A CN 102346464 A CN102346464 A CN 102346464A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
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Abstract
The invention relates to a 0-20mA or 4-20mA direct current analog quantity output device. According to the technical scheme of the invention, a voltage output end AOUT and data input ends DI0-DI7 of a D/A (Digital/Analog) converter (2) are respectively and correspondingly connected with a voltage input end VIN1 and data output ends P1.0- P1.7 of a current output type operational amplifier (4), a voltage input end VIN2 and a voltage output end VOUT of an voltage output type operational amplifier (7) are respectively and correspondingly connected with a sampling output end VSP of a sampling resistor (5) and a voltage input end AIN of an A/D (Analog/Digital) converter (8), data input ends P2.0-P2.7 of a CPU (Central Processing Unit) module (1) are connected with data output ends Do0-Do7 of the A/D converter (8), a command receiving end RX of the CPU module (1) is externally connected with the upper computer, a current output end IOUT of the current output type operational amplifier (4) and a sampling input end of the sampling resistor IIN (5) are respectively and externally connected with a current input end IL1 and current output end IL2 of a load. The device has the advantages of current output accuracy, simpleness in operation and good stability.
Description
Technical field
The invention belongs to the DC output devices technical field.Be specifically related to a kind of 0～20mA or 4～20mA DC analogue quantity output device.
Background technology
In industry spot,, can produce following problem after conditioning if the signal of gathering is voltage signal and the transmission of long line: the first, because the signal of transmission is a voltage signal, transmission line is easy to receive interference of noise; The second, the distributed resistance of transmission line can produce voltage drop; The 3rd, the working power how instrument amplifier is provided at the scene also is a problem.
In order to address the above problem and avoid the influence of correlation noise, industry spot adopts DC current to come transmission signals in a large number.The reason that adopts current signal is not allow to be subject to disturb.And the current source internal resistance is infinitesimal in theory, and conductor resistance is connected on does not influence precision in the loop, on general twisted-pair power cable, can transmit hundreds of rice.Therefore, all require to have 0～20mA or 4～20mA DC analogue quantity output function in a lot of Industry Control instrument.To the DC analogue quantity output of 0～20mA or 4～20mA, main solution has following several kinds at present:
The integrated chip scheme.Chip AD694 that voltage/current conversion chip XTR111 that provides like TI company and ADI company provide etc.But this type of chip receives the interference of external environment easily, and the precision of output current is reduced.
The discrete component scheme.This type of scheme relies on operational amplifier, triode and resistance etc. to form voltage more.This type of circuit also can comparatively accurately be realized the function of steady current output, and with low cost.Therefore 0～20mA of present most of instrument or 4～20mA current output signal all are to realize with various complicated circuitry.But the defective of this type of circuit is complicated, the trouble of adjustment, and the electric current output accuracy is not high, and in addition, along with the increase of circuit complexity, the probability that fault takes place also increases.Therefore this type of circuit also can not adapt to the research and development and the application of product gradually.
Summary of the invention
The present invention is intended to overcome above-mentioned technical deficiency, and purpose provides that a kind of circuit structure is simple, the output current precision is high, simple to operate and 0～20mA or 4～20mA DC analogue quantity output device of good stability.
For realizing above-mentioned purpose, the technical scheme that the present invention adopts is: this output unit is made up of CPU module, voltage/current modular converter and sampling feedback module.The data output end P1.0-P1.7 of CPU module is connected with the voltage/current modular converter, and the data input pin P2.0-P2.7 of CPU module is connected with the sampling feedback module, the external host computer of command reception end RX of CPU module.
The voltage/current modular converter is made up of D/A converter and current-output type operational amplifier.The voltage output end A of D/A converter
OUTVoltage input end V with the current-output type operational amplifier
IN1Connect the data input pin D of D/A converter
I0-D
I7 are connected the current output terminal I of current-output type operational amplifier with the data output end P1.0-P1.7 of CPU module
OUTThe current input terminal I of external load
L1
The sampling feedback module is made up of sampling resistor, voltage output type operational amplifier and A/D converter.The voltage output end V of voltage output type operational amplifier
OUTVoltage input end A with A/D converter
INConnect the voltage input end V of voltage output type operational amplifier
IN2Sampling output terminal V with sampling resistor
SPConnect; The data output end D of A/D converter
o0-D
o7 are connected with the data input pin P2.0-P2.7 of CPU module; The sampling input end I of sampling resistor
INThe current output terminal I of external load
L2
In the technique scheme, described host computer is a kind of among computing machine, single-chip microcomputer, FPGA and the DSP; The voltage output end A of D/A converter
OUTVoltage output range and the voltage input end A of A/D converter
INInput voltage range identical.
Because adopt technique scheme, the present invention is made up of CPU module, voltage/current modular converter and sampling feedback module, and is simple in structure.In use, this output unit can be regulated automatically, and the user is simple to operate.Only need the CPU module of this output unit to be set the DC simulation electric current I of setting through user instruction
SIt is the arbitrary value in 0～20mA or the 4～20mA scope; This output unit just circulates automatically as follows, makes the DC simulation electric current I of output
OWith the DC simulation electric current I of setting
SIdentical.
The first step: if cycle index N=1, according to the DC simulation electric current I of setting
S, the CPU module is the initial voltage value that D/A converter is set a digital quantity, D/A converter converts the initial voltage value of digital quantity in the adjusting DC simulation voltage V again
1If cycle index N＞1, then the CPU module is the output voltage values that D/A converter is set the digital quantity in the adjusting, and the output voltage values of the digital quantity during D/A converter will be regulated again converts the DC simulation voltage V in the adjusting to
1
Second step: the DC simulation voltage V in the adjusting
1Convert the DC simulation electric current I in the adjusting to through the current-output type operational amplifier
R, amplify simultaneously or decay, with the DC simulation electric current I in guaranteeing to regulate
RIn 0～20mA or 4～20mA scope, the DC simulation electric current I in the adjusting
RExternal load;
The 3rd step: the DC simulation electric current I in the adjusting that sampling resistor is returned load feedback
RConvert feedback DC simulation voltage V to
2, the feedback DC simulation voltage V that voltage output type operational amplifier is changed sampling resistor
2Amplify or decay, with guarantee to amplify or decay after DC simulation voltage V
3In the input range of A/D converter, the represented current value of the current value that the magnitude of voltage of the digital quantity in guarantee regulating simultaneously is represented and the initial voltage value of digital quantity is consistent;
The 4th step: the DC simulation voltage V after A/D converter will amplify or decay
3Convert the input voltage value of digital quantity to, the CPU module compares the input voltage value of digital quantity and the initial voltage value of digital quantity, and the output voltage values of the digital quantity in will regulating according to the difference of these two magnitudes of voltage makes progress or regulates downwards; If the input voltage value of digital quantity equals the initial voltage value of digital quantity, the CPU module is the output voltage values of the digital quantity in the adjusting no longer; If the input voltage value of digital quantity is greater than the initial voltage value of digital quantity, the output voltage values of the digital quantity during the CPU module will be regulated is regulated downwards; If the input voltage value of digital quantity is less than the initial voltage value of digital quantity, the output voltage values of the digital quantity during the CPU module will be regulated is to adjusted;
Repeat the first step～the 4th step in the above-mentioned steps, circulation according to this makes the input voltage value of digital quantity equal the initial voltage value of digital quantity all the time, has realized the DC simulation current value I of this closed loop adjustment process output
O=I
S, reach customer requirements.
In addition, the close-loop feedback control of the present invention's employing had both guaranteed the DC simulation electric current I of output
OPrecision (error that can accomplish 0～20mA or 4～20mA DC simulation electric current in theory is 0); Lose under the accurate situation at some partial function of signal or circuit that disturbs even guaranteed again; This output unit still can fast automaticly be regulated, to guarantee the DC simulation electric current I of output
OWith the DC simulation electric current I of setting
SConsistent.
Therefore, the present invention has that circuit structure is simple, the output current precision is high, simple to operate and the characteristics of good stability, and this device has the wide application prospect of ten minutes.
Description of drawings
Fig. 1 is a kind of structural representation of the present invention.
Embodiment
Below in conjunction with accompanying drawing and embodiment the present invention being done further description, is not the restriction to protection domain of the present invention.
Embodiment
A kind of 0～20mA or 4～20mA DC analogue quantity output device.As shown in Figure 1, this output unit is made up of CPU module 1, voltage/current modular converter 3 and sampling feedback module 6.The data output end P1.0-P1.7 of CPU module 1 is connected with voltage/current modular converter 3, and the data input pin P2.0-P2.7 of CPU module 1 is connected with sampling feedback module 6, the external host computer of command reception end RX of CPU module 1.
Voltage/current modular converter 3 is made up of D/A converter 2 and current-output type operational amplifier 4.The voltage output end A of D/A converter 2
OUTVoltage input end V with current-output type operational amplifier 4
IN1Connect the data input pin D of D/A converter 2
I0-D
I7 are connected the current output terminal I of current-output type operational amplifier 4 with the data output end P1.0-P1.7 of CPU module 1
OUTThe current input terminal I of external load
L1
In this embodiment, host computer is a kind of among computing machine, single-chip microcomputer, FPGA and the DSP; The voltage output end A of D/A converter 2
OUTVoltage output range and the voltage input end A of A/D converter 8
INInput voltage range identical.
This embodiment is made up of CPU module 1, voltage/current modular converter 3 and sampling feedback module 6, and is simple in structure.
In use, this output unit can be regulated automatically, and the user is simple to operate.Only need the CPU module 1 of this output unit to be set the DC simulation electric current I of setting through user instruction
SIt is the arbitrary value in 0～20mA or the 4～20mA scope; This output unit just circulates automatically as follows, makes the DC simulation electric current I of output
OWith the DC simulation electric current I of setting
SIdentical.
The first step: if cycle index N=1, according to the DC simulation electric current I of setting
S, CPU module 1 is the initial voltage value that D/A converter 2 is set a digital quantity, D/A converter 2 converts the initial voltage value of digital quantity in the adjusting DC simulation voltage V again
1If cycle index N＞1, then CPU module 1 is the output voltage values that D/A converter 2 is set the digital quantity in the adjusting, and the output voltage values of the digital quantity during D/A converter 2 will be regulated again converts the DC simulation voltage V in the adjusting to
1
Second step: the DC simulation voltage V in the adjusting
1Convert the DC simulation electric current I in the adjusting to through current-output type operational amplifier 4
R, amplify simultaneously or decay, with the DC simulation electric current I in guaranteeing to regulate
RIn 0～20mA or 4～20mA scope, the DC simulation electric current I in the adjusting
RExternal load;
The 3rd step: the DC simulation electric current I in the adjusting that sampling resistor 5 is returned load feedback
RConvert feedback DC simulation voltage V to
2, the feedback DC simulation voltage V that voltage output type operational amplifier 7 is changed sampling resistor 5
2Amplify or decay, with guarantee to amplify or decay after DC simulation voltage V
3In the input range of A/D converter 8, the represented current value of the current value that the magnitude of voltage of the digital quantity in guarantee regulating simultaneously is represented and the initial voltage value of digital quantity is consistent;
The 4th step: the DC simulation voltage V after A/D converter 8 will amplify or decay
3Convert the input voltage value of digital quantity to, CPU module 1 compares the input voltage value of digital quantity and the initial voltage value of digital quantity, and the output voltage values of the digital quantity in will regulating according to the difference of these two magnitudes of voltage makes progress or regulates downwards; If the input voltage value of digital quantity equals the initial voltage value of digital quantity, CPU is the output voltage values of the digital quantity in the adjusting not; If the input voltage value of digital quantity is greater than the initial voltage value of digital quantity, the output voltage values of the digital quantity during CPU module 1 will be regulated is regulated downwards; If the input voltage value of digital quantity is less than the initial voltage value of digital quantity, the output voltage values of the digital quantity during CPU will regulate is to adjusted;
Repeat the first step～the 4th step in the above-mentioned steps, circulation according to this makes the input voltage value of digital quantity equal the initial voltage value of digital quantity all the time, has realized the DC simulation current value I of this closed loop adjustment process output
O=I
S, reach customer requirements.
In addition, the close-loop feedback control of this embodiment employing had both guaranteed the DC simulation electric current I of output
OPrecision (error that can accomplish 0～20mA or 4～20mA DC simulation electric current in theory is 0); Lose under the accurate situation at some partial function of signal or circuit that disturbs even guaranteed again; This output unit still can fast automaticly be regulated, to guarantee the DC simulation electric current I of output
OWith the DC simulation electric current I of setting
SConsistent.
Therefore, this embodiment has that circuit structure is simple, the output current precision is high, simple to operate and the characteristics of good stability, and this device has the wide application prospect of ten minutes.
Claims (2)
1. a 0～20mA or 4～20mA DC analogue quantity output device is characterized in that this output unit is made up of CPU module (1), voltage/current modular converter (3) and sampling feedback module (6); The data output end P1.0-P1.7 of CPU module (1) is connected with voltage/current modular converter (3), and the data input pin P2.0-P2.7 of CPU module (1) is connected with sampling feedback module (6), the external host computer of command reception end RX of CPU module (1);
Voltage/current modular converter (3) is made up of D/A converter (2) and current-output type operational amplifier (4); The voltage output end A of D/A converter (2)
OUTVoltage input end V with current-output type operational amplifier (4)
IN1Connect the data input pin D of D/A converter (2)
I0-D
I7 are connected the current output terminal I of current-output type operational amplifier (4) with the data output end P1.0-P1.7 of CPU module (1)
OUTThe current input terminal I of external load
L1
Sampling feedback module (6) is made up of sampling resistor (5), voltage output type operational amplifier (7) and A/D converter (8); The voltage output end V of voltage output type operational amplifier (7)
OUTVoltage input end A with A/D converter (8)
INConnect the voltage input end V of voltage output type operational amplifier (7)
IN2Sampling output terminal V with sampling resistor (5)
SPConnect; The data output end D of A/D converter (8)
o0-D
o7 are connected with the data input pin P2.0-P2.7 of CPU module (1); The sampling input end I of sampling resistor (5)
INThe current output terminal I of external load
L2
2. 0～20mA according to claim 1 or 4～20mA DC analogue quantity output device is characterized in that described host computer is a kind of among computing machine, single-chip microcomputer, FPGA and the DSP.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101584340A CN102346464A (en) | 2011-06-14 | 2011-06-14 | 0-20mA or 4-20mA direct current analog quantity output device |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101584340A CN102346464A (en) | 2011-06-14 | 2011-06-14 | 0-20mA or 4-20mA direct current analog quantity output device |
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| CN102346464A true CN102346464A (en) | 2012-02-08 |
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|---|---|---|---|
| CN2011101584340A Pending CN102346464A (en) | 2011-06-14 | 2011-06-14 | 0-20mA or 4-20mA direct current analog quantity output device |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102611372A (en) * | 2012-03-09 | 2012-07-25 | 北京经纬恒润科技有限公司 | Method and system for acquiring feedback current of driver of stepping motor |
| CN103345238A (en) * | 2013-07-31 | 2013-10-09 | 哈尔滨工业大学 | Voltage output circuit with configurable network |
| CN108983859A (en) * | 2018-08-08 | 2018-12-11 | 上海精密计量测试研究所 | Programmable power supply |
| CN110955172A (en) * | 2019-10-30 | 2020-04-03 | 中国船舶重工集团公司第七一九研究所 | Electric isolation type 0-20 mA driving circuit with output self-detection function |
| CN111323623A (en) * | 2020-03-19 | 2020-06-23 | 中国计量科学研究院 | Josephson array simulation system and method |
| CN114371335A (en) * | 2021-12-29 | 2022-04-19 | 苏州联讯仪器有限公司 | High-precision digital source meter |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5550443A (en) * | 1994-08-25 | 1996-08-27 | Samsung Electronics Co., Ltd. | Automatic beam current control circuit for multimode monitor and method thereof |
| CN2836027Y (en) * | 2005-08-18 | 2006-11-08 | 方大集团股份有限公司 | Motor winding current detecting circuit for shielded door |
| CN1885695A (en) * | 2006-05-31 | 2006-12-27 | 武汉大学 | Soft start/stop DC switch power supply and its controlling method |
| CN201583858U (en) * | 2009-11-10 | 2010-09-15 | 郑州大方桥梁机械有限公司 | Adjustable current source with self-changed double polarities based on CAN bus control |
-
2011
- 2011-06-14 CN CN2011101584340A patent/CN102346464A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5550443A (en) * | 1994-08-25 | 1996-08-27 | Samsung Electronics Co., Ltd. | Automatic beam current control circuit for multimode monitor and method thereof |
| CN2836027Y (en) * | 2005-08-18 | 2006-11-08 | 方大集团股份有限公司 | Motor winding current detecting circuit for shielded door |
| CN1885695A (en) * | 2006-05-31 | 2006-12-27 | 武汉大学 | Soft start/stop DC switch power supply and its controlling method |
| CN201583858U (en) * | 2009-11-10 | 2010-09-15 | 郑州大方桥梁机械有限公司 | Adjustable current source with self-changed double polarities based on CAN bus control |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102611372A (en) * | 2012-03-09 | 2012-07-25 | 北京经纬恒润科技有限公司 | Method and system for acquiring feedback current of driver of stepping motor |
| CN102611372B (en) * | 2012-03-09 | 2014-12-24 | 北京经纬恒润科技有限公司 | Method and system for acquiring feedback current of driver of stepping motor |
| CN103345238A (en) * | 2013-07-31 | 2013-10-09 | 哈尔滨工业大学 | Voltage output circuit with configurable network |
| CN103345238B (en) * | 2013-07-31 | 2015-08-19 | 哈尔滨工业大学 | Voltage output circuit with configurable network |
| CN108983859A (en) * | 2018-08-08 | 2018-12-11 | 上海精密计量测试研究所 | Programmable power supply |
| CN110955172A (en) * | 2019-10-30 | 2020-04-03 | 中国船舶重工集团公司第七一九研究所 | Electric isolation type 0-20 mA driving circuit with output self-detection function |
| CN111323623A (en) * | 2020-03-19 | 2020-06-23 | 中国计量科学研究院 | Josephson array simulation system and method |
| CN114371335A (en) * | 2021-12-29 | 2022-04-19 | 苏州联讯仪器有限公司 | High-precision digital source meter |
| CN114371335B (en) * | 2021-12-29 | 2022-10-18 | 苏州联讯仪器有限公司 | High-precision digital source meter |
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Application publication date: 20120208 |