CN205644341U - Adjustable current source circuit of modified - Google Patents
Adjustable current source circuit of modified Download PDFInfo
- Publication number
- CN205644341U CN205644341U CN201620449037.7U CN201620449037U CN205644341U CN 205644341 U CN205644341 U CN 205644341U CN 201620449037 U CN201620449037 U CN 201620449037U CN 205644341 U CN205644341 U CN 205644341U
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- Prior art keywords
- resistance
- operational amplifier
- potentiometer
- resistance value
- current source
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Abstract
The utility model belongs to the technical field of the power equipment technique and specifically relates to an adjustable current source circuit of modified, its characterized in that: zener diode D6's the parallelly connected back ground connection of anodal one end with first potentiometre R2 is connected behind the series resistance R1 after zener diode D6's the negative pole and first potentiometre R2's the other end are parallelly connected again, connect an operational amplifier's non inverting input end behind first potentiometre R2's the slip end series resistance R3, back relinking second potentiometre R4's one end, second potentiometre R4's other end ground connection is connected to an operational amplifier's inverting input end and an operational amplifier's output. Compared with the prior art, the utility model, there are very strong stability and higher precision in the signal generation system to the output of current signal, does not receive the interference of external environment and load, the electric current source scope of designing is 4~20mA, can satisfy on -the -spot needs.
Description
Technical field
This utility model relates to electrical equipment technical field, the adjustable current source electricity of a kind of improvement
Road.
Background technology
In the market in adjustable current source circuit, by using V-I chip to realize.Common V-I chip
Having XTR101, XTR110 etc., costly, circuit is the most more complicated for these chip prices, and element is less
It is readily obtained.
Summary of the invention
The purpose of this utility model is to overcome the deficiencies in the prior art, mainly uses NPN audion
With LM358 operational amplifier, use triode operation in magnification region, resistance-variable characteristic, and LM358
Output electric current can be made more accurate as the characteristic of comparator.
For achieving the above object, the adjustable current source circuit of a kind of improvement is designed, it is characterised in that:
Ground connection after the positive pole of Zener diode D6 and one end parallel connection of the first potentiometer R2, Zener diode D6
Negative pole and the first potentiometer R2 other end parallel connection after connect power supply again after series resistance R1；
The in-phase input end of the first operational amplifier is connected after sliding end series resistance R3 of the first potentiometer R2,
The inverting input of the first operational amplifier and the outfan of the first operational amplifier reconnect the second electricity after connecting
One end of position device R4, the other end ground connection of the second potentiometer R4；
The sliding end of the second potentiometer R4 connects the in-phase input end of the second operational amplifier, the second operation amplifier
The base stage of NPN audion is connected after outfan series resistance R5 of device；
One end of resistance R6 is connected the anti-of the second operational amplifier after the outfan parallel connection of the 3rd operational amplifier
Phase input；The other end of resistance R6 is sequentially connected in series the 3rd potentiometer R7, one end of resistance R8, resistance R8
Other end ground connection, the sliding end of the 3rd potentiometer R7 connects the inverting input of the 3rd operational amplifier；
After the emitter stage of NPN audion and the in-phase input end parallel connection of the 3rd operational amplifier, reconnect resistance
One end of R9, the other end ground connection of resistance R9；
The colelctor electrode of NPN audion connects one end of ammeter, and the other end of ammeter connects power supply；
Described the first operational amplifier, the second operational amplifier, the 3rd operational amplifier are respectively adopted LM358
Operational amplifier.
Described Zener diode D6 uses 5.1V Zener diode；The resistance value of described resistance R1 is 1K；
The resistance value of the first potentiometer R2 is 5K；The resistance value of resistance R3 is 1K；The resistance of the second potentiometer R4
Value is 1K；The resistance value of resistance R5 is 1K；The resistance value of resistance R6 is 1K；The electricity of the 3rd potentiometer R7
Resistance is 5K；The resistance value of resistance R8 is 1K；The resistance value of resistance R9 is 0.1K.
The output area of described ammeter is 4～20mA.
Compared with prior art, the output of current signal is had the strongest steady this utility model by signal generating system
Qualitative and higher precision, is not disturbed by external environment and load；The current source scope designed be 4～
20mA, can meet the needs at scene.
Accompanying drawing explanation
Fig. 1 is circuit theory diagrams of the present utility model.
Detailed description of the invention
In conjunction with accompanying drawing, the utility model is further described.
Embodiment 1
Seeing Fig. 1, this utility model current source mainly uses relatively common LM358 operational amplifier, NPN
Audion and Zener diode etc. form, and output area is 4～20mA.Main with LM358 collection in circuit
One-tenth operational amplifier is core, is made up of adjustable voltage module and adjustable current module, uses 5V in circuit
Circuit, arranges the output signal of signal generator by precision resistance dividing potential drop in adjustable voltage module, thus
Export one 0～the change in voltage of 5V, the most again in adjustable current module, according to the line of voltage Yu electric current
Sexual relationship, by NPN triode operation in magnification region, the characteristic of resistance-variable, exports high-precision electricity
Stream signal.See Fig. 1, the following circuit of concrete employing:
Adjustable voltage module: ground connection after the positive pole of Zener diode D6 and one end parallel connection of the first potentiometer R2,
Electricity is connected again after series resistance R1 after the negative pole of Zener diode D6 and the other end parallel connection of the first potentiometer R2
Source；Wherein, Zener diode D6 uses 5.1V Zener diode；The resistance value of described resistance R1 is 1K；
The resistance value of the first potentiometer R2 is 5K.By the first potentiometer R2, make the electricity that adjustable voltage module produces
Pressure is maintained at 0～5V adjustable extent.
Voltage follower: connect the first operational amplifier after sliding end series resistance R3 of the first potentiometer R2
The in-phase input end of LM358-1, inverting input and first computing of the first operational amplifier LM358-1 are put
The outfan of big device LM358-1 reconnects one end of the second potentiometer R4 after connecting, the second potentiometer R4's
Other end ground connection.Wherein, the resistance value of resistance R3 be 1K, the resistance value of the second potentiometer R4 be 1K.The
Two potentiometer R4 are accurate slide resistors, play accurate dividing potential drop effect.And in adjustable voltage module
Zener diode D6 can guarantee that the voltage U01 of the outfan of the first operational amplifier LM358-1 be constantly equal to 0～
5V；The voltage of 0～5V simultaneously produced in adjustable voltage module, after this voltage follower, can make output
Voltage more stable.
Adjustable current module: the sliding end of the second potentiometer R4 in adjustable voltage module connects the second computing and puts
The in-phase input end of big device LM358-2, outfan series resistance R5 of the second operational amplifier LM358-2
The base stage of rear connection NPN audion；One end of resistance R6 and the outfan of the 3rd operational amplifier LM358-3
The inverting input of the second operational amplifier LM358-2 is connected after parallel connection；The other end of resistance R6 is sequentially connected in series
3rd potentiometer R7, one end of resistance R8, the other end ground connection of resistance R8, the slip of the 3rd potentiometer R7
End connects the inverting input of the 3rd operational amplifier LM358-3；The emitter stage of NPN audion and the 3rd computing
After the in-phase input end parallel connection of amplifier LM358-3, reconnect one end of resistance R9, another of resistance R9
End ground connection；The colelctor electrode of NPN audion connects one end of ammeter, and the other end of ammeter connects power supply.
Wherein, the resistance value of resistance R5 is 1K；The resistance value of resistance R6 is 1K；3rd potentiometer R7's
Resistance value is 5K；The resistance value of resistance R8 is 1K.The in-phase input end of the second operational amplifier LM358-2
Voltage U02 be 0～5V, in order to make output electric current be 4～20mA, resistance R9=100 Ω to be chosen.
According to the relation of U=IR, the scope of the voltage U05 at resistance R9 two ends is necessary for 0.4V～2V.Then
By the 3rd operational amplifier LM358-3, U05 is amplified 2.5 times, export the second operational amplifier LM358-2
Inverting input, the second operational amplifier act as the effect of a comparator, utilizes NPN tri-pole simultaneously
Pipe is operated in the characteristic of magnification region, it is ensured that make the in-phase input end voltage of the second operational amplifier LM358-2
Equal with anti-phase input terminal voltage.The output voltage that this guarantees U05 is 0.4～2V, again because of NPN tri-
Collector current and the emitter current of pole pipe are almost equal, so the exporting change scope of ammeter is 4～20
mA.The biggest number requirement of engineering is disclosure satisfy that, the output curent change emulation knot under different magnitudes of voltage through emulation
Fruit is such as following table:
Claims (3)
1. the adjustable current source circuit improved, it is characterised in that:
Ground connection after the positive pole of Zener diode D6 and one end parallel connection of the first potentiometer R2, voltage stabilizing two pole
Power supply is connected again after series resistance R1 after the negative pole of pipe D6 and the other end parallel connection of the first potentiometer R2；
The homophase connecting the first operational amplifier after sliding end series resistance R3 of the first potentiometer R2 is defeated
Enter end, after the inverting input of the first operational amplifier and the outfan connection of the first operational amplifier again
Connect one end of the second potentiometer R4, the other end ground connection of the second potentiometer R4；
The sliding end of the second potentiometer R4 connects the in-phase input end of the second operational amplifier, the second fortune
The base stage of NPN audion is connected after calculating outfan series resistance R5 of amplifier；
One end of resistance R6 is connected the second operation amplifier after the outfan parallel connection of the 3rd operational amplifier
The inverting input of device；The other end of resistance R6 be sequentially connected in series the 3rd potentiometer R7, the one of resistance R8
End, the other end ground connection of resistance R8, the sliding end of the 3rd potentiometer R7 connects the 3rd operational amplifier
Inverting input,
After the emitter stage of NPN audion and the in-phase input end parallel connection of the 3rd operational amplifier, reconnect
One end of resistance R9, the other end ground connection of resistance R9；
The colelctor electrode of NPN audion connects one end of ammeter, and the other end of ammeter connects power supply；
Described the first operational amplifier, the second operational amplifier, the 3rd operational amplifier are respectively adopted
LM358 operational amplifier.
The adjustable current source circuit of a kind of improvement the most as claimed in claim 1, it is characterised in that: described is steady
Pressure diode D6 uses 5.1V Zener diode；The resistance value of described resistance R1 is 1K；First
The resistance value of potentiometer R2 is 5K；The resistance value of resistance R3 is 1K；The resistance of the second potentiometer R4
Value is 1K；The resistance value of resistance R5 is 1K；The resistance value of resistance R6 is 1K；3rd potentiometer R7
Resistance value be 5K；The resistance value of resistance R8 is 1K；The resistance value of resistance R9 is 0.1K.
The adjustable current source circuit of a kind of improvement the most as claimed in claim 1, it is characterised in that: described electricity
The output area of stream table is 4～20mA.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620449037.7U CN205644341U (en) | 2016-05-17 | 2016-05-17 | Adjustable current source circuit of modified |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620449037.7U CN205644341U (en) | 2016-05-17 | 2016-05-17 | Adjustable current source circuit of modified |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205644341U true CN205644341U (en) | 2016-10-12 |
Family
ID=57057509
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620449037.7U Expired - Fee Related CN205644341U (en) | 2016-05-17 | 2016-05-17 | Adjustable current source circuit of modified |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205644341U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112835406A (en) * | 2021-03-10 | 2021-05-25 | 京东方科技集团股份有限公司 | Constant current source circuit, driving method thereof and current control device |
-
2016
- 2016-05-17 CN CN201620449037.7U patent/CN205644341U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112835406A (en) * | 2021-03-10 | 2021-05-25 | 京东方科技集团股份有限公司 | Constant current source circuit, driving method thereof and current control device |
| CN112835406B (en) * | 2021-03-10 | 2022-12-09 | 京东方科技集团股份有限公司 | Constant current source circuit, driving method thereof and current control device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20161012 Termination date: 20210517 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |