CN205880721U - Adjustable constant current source circuit - Google Patents
Adjustable constant current source circuit Download PDFInfo
- Publication number
- CN205880721U CN205880721U CN201620753057.3U CN201620753057U CN205880721U CN 205880721 U CN205880721 U CN 205880721U CN 201620753057 U CN201620753057 U CN 201620753057U CN 205880721 U CN205880721 U CN 205880721U
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- China
- Prior art keywords
- field effect
- effect transistor
- circuit
- resistance
- adjustable constant
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Abstract
The utility model relates to an adjustable constant current source circuit, produce circuit, drive circuit and field effect transistor including PWM, the output of PWM production circuit links to each other with drive circuit's input, drive circuit's output links to each other with field effect transistor's grid, field effect transistor's drain electrode links to each other with the load. The utility model discloses the realization is to the control of adjustable big current control component.
Description
Technical field
This utility model relates to constant-current source circuit, particularly relates to a kind of adjustable constant flow source circuit.
Background technology
Constant-current source be not with load change in resistance, for load provide constant current power supply, its robot, LED drive,
Power communications etc. have application.At some control fields, the control signal of some element is electric current, and the size of input current controls
The duty that element is different, and, it is desirable to it is the biggest that input current reaches 1A.And electricity of typically its output of constant-current source circuit
Stream is tens milliamperes, and can not adjust, or output still its precision being capable of big electric current is the highest.
Utility model content
Technical problem to be solved in the utility model is to provide a kind of adjustable constant flow source circuit, it is achieved to adjustable great current
Control the control of element.
This utility model solves its technical problem and be the technical scheme is that a kind of adjustable constant flow source circuit of offer, bag
Including PWM and produce circuit, drive circuit and field effect transistor, described PWM produces the outfan of circuit and the input phase of drive circuit
Even, the outfan of described drive circuit is connected with the grid of field effect transistor, and the drain electrode of described field effect transistor is connected with load.
Described PWM produces circuit and is used for producing unipolar pwm signal, and the dutycycle of described pwm signal can be carried out
Control to adjust.
Described drive circuit includes High voltage output buffer, photoelectrical coupler, the first resistance and the second resistance, described photoelectricity
Bonder is isolated form photoelectrical coupler, and the outfan that the input of described High voltage output buffer produces circuit with PWM is connected,
Outfan is connected with the input of isolated form photoelectrical coupler；The outfan of described isolated form photoelectrical coupler passes through the first resistance
With the second resistance eutral grounding；Node between described first resistance and the second resistance is connected with the grid of field effect transistor.
Described isolated form photoelectrical coupler uses ACPL-T350 chip, and the ANODE end of described ACPL-T350 chip is with high
The outfan of pressure output buffer is connected；The Vo end of described ACPL-T350 chip passes through the first resistance and the second resistance eutral grounding.
Described drive circuit includes High voltage output buffer, photoelectrical coupler, the first resistance and the second resistance, described photoelectricity
Bonder uses ACPL-T350 chip, the outfan that the input of described High voltage output buffer produces circuit with PWM to be connected,
Outfan is connected with the ANODE end of ACPL-T350 chip；The Vo end of described ACPL-T350 chip passes through the first resistance and second
Resistance eutral grounding；Node between described first resistance and the second resistance is connected with the grid of field effect transistor.
The two ends, left and right of described ACPL-T350 chip use different power supplys.
Described PWM produces and is additionally provided with a pull down resistor between circuit and High voltage output buffer.
Described field effect transistor is N-channel field effect transistor, the grid outputing signal to field effect transistor of described drive circuit；
The source ground of field effect transistor, and power supply connect with described load is altogether；The drain electrode of field effect transistor is connected with load one end, load
Another terminates positive supply.
Described field effect transistor is P-channel field-effect transistor (PEFT) pipe, the grid outputing signal to field effect transistor of described drive circuit；
The source electrode of field effect transistor connects positive supply；The drain electrode of field effect transistor is connected with load one end, loads other end ground connection.
The outfan of described field effect transistor is additionally provided with diode.
Beneficial effect
Owing to have employed above-mentioned technical scheme, this utility model compared with prior art, has the following advantages that and amasss
Pole effect: this utility model is by the Duty ratio control to pwm signal, it is achieved the constant-current source circuit of output adjustable current size,
This utility model circuit can be good with output linearity degree, and stability is high, the maximum big electric current up to several amperes.
Accompanying drawing explanation
Fig. 1 is structured flowchart of the present utility model；
Fig. 2 is the circuit diagram of this utility model embodiment.
Detailed description of the invention
Below in conjunction with specific embodiment, this utility model is expanded on further.Should be understood that these embodiments are merely to illustrate this
Utility model rather than limit scope of the present utility model.In addition, it is to be understood that reading the content that this utility model is lectured
Afterwards, this utility model can be made various changes or modifications by those skilled in the art, and these equivalent form of values fall within this Shen equally
Please appended claims limited range.
Embodiment of the present utility model relates to a kind of adjustable constant flow source circuit, as it is shown in figure 1, include that PWM produces circuit
101, drive circuit 102 and field effect transistor 103, described PWM produces the outfan of circuit 101 and the input of drive circuit 102
Being connected, the outfan of described drive circuit 102 is connected with the grid of field effect transistor 103, and the drain electrode of described field effect transistor 103 is with negative
Carry 104 to be connected.Wherein, described PWM generation circuit is used for producing unipolar pwm signal, and the dutycycle energy of described pwm signal
Enough it is controlled adjusting, by the Duty ratio control to pwm signal, can realize exporting the adjustable purpose of size of current.
As in figure 2 it is shown, described drive circuit includes High voltage output buffer, photoelectrical coupler, the first resistance R2 and second
Resistance R5, described High voltage output buffer uses 7407 chips, and described photoelectrical coupler uses ACPL-T350 chip, described height
The outfan that the input of pressure output buffer produces circuit with PWM is connected, outfan and the ANODE end of ACPL-T350 chip
It is connected；Wherein, described PWM produces and is additionally provided with a pull down resistor R4, by under this between circuit and High voltage output buffer
Pull-up resistor R4 makes signal input for can be clearly zero during low level.The Vo end of described ACPL-T350 chip is by the first electricity
Resistance R2 and the second resistance R5 ground connection；The grid phase of the node between described first resistance R2 and the second resistance R5 and field effect transistor
Even.Wherein, described field effect transistor is N-channel field effect transistor, the source ground of field effect transistor, and power supply connect with described load
Altogether；The drain electrode of field effect transistor is connected with load one end, loads another termination positive supply.The outfan of described field effect transistor is also
Being provided with diode D1, this diode D1 can play a protective role.
It should be noted that the drive circuit in present embodiment can also is that the drive circuit of other forms, as long as its
It is capable of driving the purpose of field effect transistor.
It is noted that described field effect transistor can also be P-channel field-effect transistor (PEFT) pipe, when field effect transistor uses P-channel
During field effect transistor, the grid outputing signal to field effect transistor of described drive circuit；The source electrode of field effect transistor connects positive supply；Field effect
Should pipe drain electrode with load one end be connected, load other end ground connection.
In present embodiment, the pwm signal that pwm signal produces is unipolar pwm signal, and it exports Transistor-Transistor Logic level signal,
High level is positive voltage, and low level is 0V.ACPL-T350 chip drives element drives field effect as the field effect transistor of isolated form
Pipe, is using different power supplys (left end is VCC, and right-hand member is A20V) simultaneously around, the interference introduced at isolation load, improves
The stability of system.
Claims (9)
1. an adjustable constant flow source circuit, it is characterised in that include that PWM produces circuit, drive circuit and field effect transistor, described
PWM produces the outfan of circuit and is connected with the input of drive circuit, the outfan of described drive circuit and the grid of field effect transistor
The most connected, the drain electrode of described field effect transistor is connected with load.
Adjustable constant flow source circuit the most according to claim 1, it is characterised in that described PWM produces circuit and is used for producing list
The pwm signal of polarity, and the dutycycle of described pwm signal can be controlled adjust.
Adjustable constant flow source circuit the most according to claim 1, it is characterised in that described drive circuit includes that High voltage output delays
Rushing device, photoelectrical coupler, the first resistance and the second resistance, described photoelectrical coupler is isolated form photoelectrical coupler, described high pressure
The outfan that the input of output buffer produces circuit with PWM is connected, outfan and the input of isolated form photoelectrical coupler
It is connected；The outfan of described isolated form photoelectrical coupler passes through the first resistance and the second resistance eutral grounding；Described first resistance and
Node between two resistance is connected with the grid of field effect transistor.
Adjustable constant flow source circuit the most according to claim 3, it is characterised in that described isolated form photoelectrical coupler uses
ACPL-T350 chip, the ANODE end of described ACPL-T350 chip is connected with the outfan of High voltage output buffer；Described
The Vo end of ACPL-T350 chip passes through the first resistance and the second resistance eutral grounding.
Adjustable constant flow source circuit the most according to claim 4, it is characterised in that the left and right two of described ACPL-T350 chip
End uses different power supplys.
Adjustable constant flow source circuit the most according to claim 3, it is characterised in that described PWM produces circuit and High voltage output
A pull down resistor it is additionally provided with between buffer.
Adjustable constant flow source circuit the most according to claim 1, it is characterised in that described field effect transistor is N-channel field effect
Ying Guan, the grid outputing signal to field effect transistor of described drive circuit；The source ground of field effect transistor, and with described load institute
Connect power supply altogether；The drain electrode of field effect transistor is connected with load one end, loads another termination positive supply.
Adjustable constant flow source circuit the most according to claim 1, it is characterised in that described field effect transistor is P-channel field effect
Ying Guan, the grid outputing signal to field effect transistor of described drive circuit；The source electrode of field effect transistor connects positive supply；Field effect transistor
Drain and be connected with load one end, load other end ground connection.
Adjustable constant flow source circuit the most according to claim 1, it is characterised in that the outfan of described field effect transistor also sets
There is diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620753057.3U CN205880721U (en) | 2016-07-15 | 2016-07-15 | Adjustable constant current source circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620753057.3U CN205880721U (en) | 2016-07-15 | 2016-07-15 | Adjustable constant current source circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205880721U true CN205880721U (en) | 2017-01-11 |
Family
ID=57696244
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620753057.3U Withdrawn - After Issue CN205880721U (en) | 2016-07-15 | 2016-07-15 | Adjustable constant current source circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205880721U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106055004A (en) * | 2016-07-15 | 2016-10-26 | 宁波帝洲自动化科技有限公司 | Adjustable constant current source circuit |
-
2016
- 2016-07-15 CN CN201620753057.3U patent/CN205880721U/en not_active Withdrawn - After Issue
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106055004A (en) * | 2016-07-15 | 2016-10-26 | 宁波帝洲自动化科技有限公司 | Adjustable constant current source circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20170111 Effective date of abandoning: 20180227 |