CN104460496A - Numerical control constant current source circuit based on PLC - Google Patents

Numerical control constant current source circuit based on PLC Download PDF

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Publication number
CN104460496A
CN104460496A CN201410849557.2A CN201410849557A CN104460496A CN 104460496 A CN104460496 A CN 104460496A CN 201410849557 A CN201410849557 A CN 201410849557A CN 104460496 A CN104460496 A CN 104460496A
Authority
CN
China
Prior art keywords
plc
circuit
input end
control constant
source circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201410849557.2A
Other languages
Chinese (zh)
Inventor
徐庆富
江明珠
李清卉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GUILIN MYAO ELECTRONIC TECHNOLOGY Co Ltd
Original Assignee
GUILIN MYAO ELECTRONIC TECHNOLOGY Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GUILIN MYAO ELECTRONIC TECHNOLOGY Co Ltd filed Critical GUILIN MYAO ELECTRONIC TECHNOLOGY Co Ltd
Priority to CN201410849557.2A priority Critical patent/CN104460496A/en
Publication of CN104460496A publication Critical patent/CN104460496A/en
Pending legal-status Critical Current

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Classifications

    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00Programme-control systems
    • G05B19/02Programme-control systems electric
    • G05B19/04Programme control other than numerical control, i.e. in sequence controllers or logic controllers
    • G05B19/05Programmable logic controllers, e.g. simulating logic interconnections of signals according to ladder diagrams or function charts
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05FSYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10Regulating voltage or current
    • G05F1/46Regulating voltage or current wherein the variable actually regulated by the final control device is dc
    • G05F1/56Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices
    • G05F1/565Regulating voltage or current wherein the variable actually regulated by the final control device is dc using semiconductor devices in series with the load as final control devices sensing a condition of the system or its load in addition to means responsive to deviations in the output of the system, e.g. current, voltage, power factor

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Electromagnetism (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Amplifiers (AREA)

Abstract

The invention discloses a numerical control constant current source circuit based on a PLC. The numerical control constant current source circuit comprises the PLC, a keyboard, a DAC, a low-pass filter, an operation amplifier, a current output circuit and an ADC conversion circuit. The output end of the PLC is connected with the input end of the DAC, the output end of the DAC is connected with the input end of the low-pass filter, the output end of the low-pass filter is connected with the input end of the current output circuit and the input end of the ADC conversion circuit, the output end of the ADC conversion circuit is connected with the input end of the PLC, and the keyboard is connected with the input end of the PLC. The numerical control constant current source circuit has the advantages that the accuracy and the efficiency of the circuit are improved, errors and power losses caused by power amplification can be reduced, and a flexible and adjustable microampere-level current can be output.

Description

Based on PLC digital-control constant-flow source circuit
Technical field
The present invention relates to a kind of constant-current source circuit, be specifically related to based on PLC digital-control constant-flow source circuit.
Background technology
Constant current source is that a kind of extraneous electric network source produces fluctuation or electric network impedance characteristic changes, and still can keep constant current source by output current.Microampere order constant current source is compared with general constant-current source circuit, and microampere order constant current source output current is little, is widely used in intelligent instrument and advanced detection technique.But microampere order constant current source is vulnerable to the impact of ripple and noise in circuit.At present, the magnitude of voltage that microampere order constant current source mainly exports as requested, single-chip microcomputer calculates corresponding magnitude of voltage, by DA conversion links output voltage, the process of circuit after filtering, with links such as operational amplifier, transistor, current sampling circuit and Voltage to current transducer, export constant electric current in loop, pull-up resistor place.But have the leakage current of several microamperes or few tens of microamps, affect the precision of circuit, power attenuation is large, far exceedes the error range that microampere order circuit allows, and can not meet the demand exporting small area analysis.So, develop and a kind ofly can reduce error because power amplification causes and power attenuation, export high-precision current, improve circuit efficiency, there is important practical significance.
Summary of the invention
The technical problem to be solved in the present invention be to provide a kind of have improve the precision of circuit and efficiency, the error because power amplification causes and power attenuation can be reduced, export microampere order constant current adjustable flexibly based on PLC digital-control constant-flow source circuit.
Based on PLC digital-control constant-flow source circuit, comprise PLC, keyboard, DAC converter, low-pass filter, operational amplifier, current output circuit, ADC change-over circuit, the output terminal of described PLC connects the input end of DAC converter, the output terminal of DAC converter connects the input end of low-pass filter, the output terminal of low-pass filter connects the input end of current output circuit and ADC change-over circuit respectively, the output terminal of ADC change-over circuit connects the input end of PLC, and described keyboard connects the input end of PLC.
Further, described PLC output terminal is also connected with display circuit, convenient display electric current current set value and electric current moment output valve.
Further, current detecting amplifying circuit is also connected with between described operational amplifier and ADC change-over circuit.
Preferably, described operational amplifier is FET type amplifier.
Beneficial effect of the present invention is: the present invention arranges output current value by keyboard, data are sent into liquid crystal display display current set value by PLC, data are sent into DAC converter simultaneously, after low-pass filter, operational amplifier process, export the adjustable microampere order constant current source of numerical control; This signal is converted to digital signal by ADC, and these data are read in internal data memory by PLC, by the feedback element of digital quantity form, makes electric current more stable, then sends into LED display, sees predetermined value and output valve by display.
Accompanying drawing explanation
Fig. 1 is the structured flowchart that the present invention is based on PLC digital-control constant-flow source circuit.
Embodiment
Accompanying drawing discloses concrete structure of the present invention without limitation, and below in conjunction with accompanying drawing, the invention will be further described.
As shown in Figure 1, based on PLC digital-control constant-flow source circuit, comprise PLC, keyboard, DAC converter, low-pass filter, operational amplifier, current output circuit, ADC change-over circuit, the output terminal of described PLC connects the input end of DAC converter, the output terminal of DAC converter connects the input end of low-pass filter, the output terminal of low-pass filter connects the input end of current output circuit and ADC change-over circuit respectively, the output terminal of ADC change-over circuit connects the input end of PLC, and described keyboard connects the input end of PLC.Described PLC output terminal is also connected with display circuit.Current detecting amplifying circuit is also connected with between described operational amplifier and ADC change-over circuit.Described operational amplifier is FET type amplifier.

Claims (4)

1. based on PLC digital-control constant-flow source circuit, comprise PLC, keyboard, DAC converter, low-pass filter, operational amplifier, current output circuit, ADC change-over circuit, it is characterized in that: the output terminal of described PLC connects the input end of DAC converter, the output terminal of DAC converter connects the input end of low-pass filter, the output terminal of low-pass filter connects the input end of current output circuit and ADC change-over circuit respectively, the output terminal of ADC change-over circuit connects the input end of PLC, and described keyboard connects the input end of PLC.
2. according to claim 1 based on PLC digital-control constant-flow source circuit, it is characterized in that: described PLC output terminal is also connected with display circuit.
3. according to claim 1 based on PLC digital-control constant-flow source circuit, it is characterized in that: between described operational amplifier and ADC change-over circuit, be also connected with current detecting amplifying circuit.
4. according to claim 1 based on PLC digital-control constant-flow source circuit, it is characterized in that: described operational amplifier is FET type amplifier.
CN201410849557.2A 2014-12-31 2014-12-31 Numerical control constant current source circuit based on PLC Pending CN104460496A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201410849557.2A CN104460496A (en) 2014-12-31 2014-12-31 Numerical control constant current source circuit based on PLC

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201410849557.2A CN104460496A (en) 2014-12-31 2014-12-31 Numerical control constant current source circuit based on PLC

Publications (1)

Publication Number Publication Date
CN104460496A true CN104460496A (en) 2015-03-25

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN201410849557.2A Pending CN104460496A (en) 2014-12-31 2014-12-31 Numerical control constant current source circuit based on PLC

Country Status (1)

Country Link
CN (1) CN104460496A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106023661A (en) * 2016-06-24 2016-10-12 南京恒立达光电有限公司 Integrated teaching and scientific research experiment platform
CN106054714A (en) * 2016-06-24 2016-10-26 南京恒立达光电有限公司 General numerical control power supply

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201378188Y (en) * 2009-04-23 2010-01-06 中南林业科技大学 Numerically-controlled resistance measurement device
CN201470476U (en) * 2009-08-31 2010-05-19 襄樊九鼎昊天环保设备有限公司 PLC-touch screen control constant curernt source
CN201955696U (en) * 2010-01-07 2011-08-31 张永炬 High-precision numerical control constant current source
CN204302754U (en) * 2014-12-31 2015-04-29 桂林铭瑶电子科技有限公司 Based on PLC digital-control constant-flow source circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201378188Y (en) * 2009-04-23 2010-01-06 中南林业科技大学 Numerically-controlled resistance measurement device
CN201470476U (en) * 2009-08-31 2010-05-19 襄樊九鼎昊天环保设备有限公司 PLC-touch screen control constant curernt source
CN201955696U (en) * 2010-01-07 2011-08-31 张永炬 High-precision numerical control constant current source
CN204302754U (en) * 2014-12-31 2015-04-29 桂林铭瑶电子科技有限公司 Based on PLC digital-control constant-flow source circuit

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106023661A (en) * 2016-06-24 2016-10-12 南京恒立达光电有限公司 Integrated teaching and scientific research experiment platform
CN106054714A (en) * 2016-06-24 2016-10-26 南京恒立达光电有限公司 General numerical control power supply
CN106054714B (en) * 2016-06-24 2018-05-11 南京恒立达光电有限公司 A kind of Universal digital control power
CN106023661B (en) * 2016-06-24 2018-07-10 南京恒立达光电有限公司 A kind of teaching and scientific research synthesis experiment platform

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Application publication date: 20150325