CN202486646U - Constant current circuit - Google Patents
Constant current circuit Download PDFInfo
- Publication number
- CN202486646U CN202486646U CN2012200880169U CN201220088016U CN202486646U CN 202486646 U CN202486646 U CN 202486646U CN 2012200880169 U CN2012200880169 U CN 2012200880169U CN 201220088016 U CN201220088016 U CN 201220088016U CN 202486646 U CN202486646 U CN 202486646U
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- Prior art keywords
- mos transistor
- operational amplifier
- power supply
- utility
- model
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Abstract
The utility model discloses a constant current circuit which comprises the following components: an operational amplifier, an MOS (Metal Oxide Semiconductor) transistor, a reference power supply, a load circuit and a resistor, wherein an inverting input terminal of the operational amplifier is connected with one end of the resistor and is also connected with a source electrode of the MOS transistor; the other end of the resistor is grounded; a noninverting input terminal of the operational amplifier is connected with the reference power supply; an output end of the operational amplifier is connected with a grid electrode of the MOS transistor; and a drain electrode of the MOS transistor is connected with a cathode of the load circuit. According to the utility model, a stable and accurate current value can be acquired; and meanwhile, the constant current circuit has the advantages of simple structure, low cost and wide application range.
Description
Technical field
The utility model relates to a kind of constant-current circuit.
Background technology
In recent years; Constant-current circuit plays an important role in circuit such as battery feed circuit and constant-current drive circuit; This mainly be since in theory constant-current circuit can fill and part utilize battery electric power, thereby maximum continuation of the journey is provided, continue constant voltage and also there is a kind of battery to provide now.
But conventional constant-current circuit often has shortcomings such as complex structure, cost height, narrow application range because it is to design to concrete application.
The utility model content
The purpose of the utility model is, a kind of constant-current circuit is provided, and can obtain stable and precise current value, has characteristics simple in structure, that cost is low, the scope of application is wide simultaneously.
For achieving the above object, the utility model adopts following technical scheme:
A kind of constant-current circuit; Comprise operational amplifier, MOS transistor, resistance, reference power supply and load circuit, the inverting input of said operational amplifier is connected with an end of resistance, is connected with the source electrode of MOS transistor simultaneously; The other end of said resistance connects ground; The in-phase input end of said operational amplifier connects reference power supply, and the output terminal of said operational amplifier is connected with the grid of MOS transistor, and the drain electrode of said MOS transistor is connected with the negative pole of load circuit.
In this constant-current circuit, said MOS transistor is that the N ditch strengthens MOS transistor.
The beneficial effect of the utility model is: the utility model can obtain stable and precise current value, has advantage simple in structure, that cost is low, the scope of application is wide simultaneously.
Description of drawings
Fig. 1 is a constant-current circuit circuit diagram in the utility model.
Description of reference numerals:
U1 ... Operational amplifier;
Q1 ... The N ditch strengthens MOS transistor;
R1 ... Resistance;
V
REFThe reference voltage that reference power supply provides;
V
Cc1The supply voltage that the power supply of load circuit provides;
V
Cc2The supply voltage that the power supply of operational amplifier provides;
G ... The N ditch strengthens the grid of MOS transistor;
S ... The N ditch strengthens the source electrode of MOS transistor;
D ... The N ditch strengthens the drain electrode of MOS transistor.
Embodiment
For the purpose, technical scheme and the advantage that make the utility model is clearer,, the utility model is further elaborated below in conjunction with accompanying drawing and embodiment.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
See also Fig. 1, in an embodiment of the utility model, said constant-current circuit comprises operational amplifier U1; MOS transistor, promptly the N ditch strengthens MOS transistor Q1; Reference power supply and resistance R 1.
The inverting input of operational amplifier U1 links to each other with an end of resistance R 1, and the source S with N ditch enhancing MOS transistor is connected simultaneously, and the other end of R1 connects ground; The in-phase input end of operational amplifier U1 connects reference power supply, and output terminal is connected with the grid G that the N ditch strengthens MOS transistor Q1; And the N ditch strengthens the negative pole that the drain D of MOS transistor connects load circuit, and the positive pole of said load circuit is connected with its power supply, and the supply voltage that this power supply provides is V
Cc1, said operational amplifier U1 is connected with its power supply, and the supply voltage that this power supply provides is V
Cc2
During the utility model work, resistance R 1 is a sample resistance, and reference power supply is to given voltage V of in-phase input end input of operational amplifier U1
REF, the electrorheological in load circuit hour can cause the electric current on the resistance R 1 to diminish, and then the voltage decreases on the resistance R 1, and the voltage decreases of the reverse input end of operational amplifier U1 just is because operational amplifier U1 is to V
REFAmplify with the difference of the voltage of reverse input end, so this moment, operational amplifier U1 then can increase output, the conducting electric current that makes the N ditch strengthen MOS transistor Q1 increases, and then the electric current in the load circuit is strengthened; When the electrorheological in the load circuit is big, can cause the electrorheological on the resistance R 1 big, and then the voltage on the resistance R 1 become big; Just the voltage of the reverse input of operational amplifier U1 becomes big; In like manner operational amplifier U1 then can reduce output, makes the N ditch strengthen MOS transistor Q1 conducting electric current and reduces, and then the electric current in the load circuit is diminished; Electric current in the load circuit finally maintains constant giving on the value like this, has realized constant current work.
Change V
REFCan change the constant current value of electric current in the load circuit, V
REFAvailable potentiometer is regulated input or is imported by MCU control with the DAC chip, but adopts potentiometer manual adjustments output current, adopts the DAC input can realize numerical control constant current electronic load.
The preferred embodiment that the above is merely the utility model is not the practical range that is used for limiting the utility model; If do not break away from the spirit and the scope of the utility model, the utility model is made amendment or is equal to replacement, all should be encompassed in the middle of the protection domain of the utility model claim.
Claims (2)
1. a constant-current circuit is characterized in that, comprises operational amplifier, MOS transistor, resistance, reference power supply and load circuit; The inverting input of said operational amplifier is connected with an end of resistance; Be connected with the source electrode of MOS transistor simultaneously, the other end of said resistance connects ground, and the in-phase input end of said operational amplifier connects reference power supply; The output terminal of said operational amplifier is connected with the grid of MOS transistor, and the drain electrode of said MOS transistor is connected with the negative pole of load circuit.
2. constant-current circuit according to claim 1 is characterized in that, said MOS transistor is that the N ditch strengthens MOS transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012200880169U CN202486646U (en) | 2012-03-09 | 2012-03-09 | Constant current circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012200880169U CN202486646U (en) | 2012-03-09 | 2012-03-09 | Constant current circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202486646U true CN202486646U (en) | 2012-10-10 |
Family
ID=46961055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012200880169U Expired - Fee Related CN202486646U (en) | 2012-03-09 | 2012-03-09 | Constant current circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202486646U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112859980A (en) * | 2021-01-12 | 2021-05-28 | 东莞浩立自动化科技有限公司 | Constant current control system for intelligently detecting load and control method thereof |
| CN113258435A (en) * | 2021-07-02 | 2021-08-13 | 中科慧远视觉技术(北京)有限公司 | Narrow-pulse-width high-power laser constant-current driving circuit and optical module |
| CN113364259A (en) * | 2021-06-11 | 2021-09-07 | 深圳市费思泰克科技有限公司 | Constant-current bleeder circuit with time-delay turn-off protection |
-
2012
- 2012-03-09 CN CN2012200880169U patent/CN202486646U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112859980A (en) * | 2021-01-12 | 2021-05-28 | 东莞浩立自动化科技有限公司 | Constant current control system for intelligently detecting load and control method thereof |
| CN113364259A (en) * | 2021-06-11 | 2021-09-07 | 深圳市费思泰克科技有限公司 | Constant-current bleeder circuit with time-delay turn-off protection |
| CN113258435A (en) * | 2021-07-02 | 2021-08-13 | 中科慧远视觉技术(北京)有限公司 | Narrow-pulse-width high-power laser constant-current driving circuit and optical module |
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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: 20121010 Termination date: 20150309 |
|
| EXPY | Termination of patent right or utility model |