CN206348387U - Low-cost electric current detection circuit - Google Patents
Low-cost electric current detection circuit Download PDFInfo
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- CN206348387U CN206348387U CN201720014039.8U CN201720014039U CN206348387U CN 206348387 U CN206348387 U CN 206348387U CN 201720014039 U CN201720014039 U CN 201720014039U CN 206348387 U CN206348387 U CN 206348387U
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Abstract
The utility model discloses a kind of Low-cost electric current detection circuit, including constantan wire, conversion chip and main control chip, the periphery of conversion chip includes first resistor, second resistance and 3rd resistor, 3rd resistor is series between current output terminal and the signal input negative terminal of conversion chip, the signal input positive terminal of conversion chip is connected together with current reflux end, the two ends of constantan wire are connected to current output terminal and current reflux end, second resistance and the second electric capacity are parallel to together and are connected to the signal output part and signal input negative terminal of conversion chip, the two ends of first resistor are connected to the signal output part and signal input positive terminal of conversion chip, it ensure that the current signal stable by constantan wire, it is not in the situation for detecting that electric current is inaccurate, and because the cost of constantan wire is low, small volume, therefore, it is possible to improve the processing efficiency of detection circuit, reduce the area of detection circuit, so as to which effectively reduction detects the cost of circuit.
Description
Technical field
The utility model is related to current detecting field, especially a kind of Low-cost electric current detection circuit.
Background technology
Current electric current detecting method, mainly uses current transformer to be detected, but current transformer cost is high, chi
Very little big, the space for taking circuit board is more, therefore is unfavorable for the miniaturization of circuit board, and because the volume of current transformer is big,
Therefore the speed that plug-in unit installation is carried out to it is slow, further, since the current transformer situation that its pin deforms in processing
It is very universal, therefore after current transformer is inserted on circuit board, stress can be produced and caused inside current transformer
Connection appearance is bad, so as to cause the situation for detecting that electric current is inaccurate.
Utility model content
To solve the above problems, the purpose of this utility model is to provide a kind of Low-cost electric current detection circuit, using putting
The current signal for flowing through constantan wire is converted to voltage signal by big device, so as to accurately be detected to electric current, due to passing through health
The electric current of copper wire is difficult to be influenceed and changed by external force, therefore, it is possible to ensure the current signal stable by constantan wire, no
The inaccurate situation of detection electric current occurs, and because the cost of constantan wire is low, small volume, therefore, it is possible to improve detection circuit
Processing efficiency, reduce detection circuit area so that effectively reduction detection circuit cost.
The technical scheme that the invention for solving the technical problem is used is：
Low-cost electric current detection circuit, including for exporting the current output terminal of current signal to be measured, for making electricity to be measured
Stream signal flowed back current reflux end, the constantan wire for gathering current signal, for by constantan wire electric current letter
Number it is converted into the conversion chip of voltage signal and for judging the big of sensed current signal according to the voltage signal being converted to
Small main control chip, the periphery of conversion chip includes the first electric capacity, the second electric capacity and the 3rd electric capacity for being used to improve stability, turns
Change first resistor, second resistance that the periphery of chip also includes being used to the current signal for flowing through constantan wire is converted to voltage signal
And 3rd resistor, 3rd resistor is series between current output terminal and the signal input negative terminal of conversion chip, the letter of conversion chip
Number input positive terminal is connected together with current reflux end, and the two ends of constantan wire are connected to current output terminal and current reflux
End, second resistance and the second electric capacity is parallel to together and two tie point is connected to the signal output part of conversion chip
With signal input negative terminal, the two ends of first resistor are connected to the signal output part and signal input positive terminal of conversion chip, the
The two ends of one electric capacity are connected to the signal input positive terminal of bias voltage and conversion chip, and the two ends of the 3rd electric capacity are connected respectively
In reference ground and the signal input negative terminal of conversion chip, the signal output part of conversion chip and the detection pin of main control chip connect
It is connected together.
Further, in addition to for suppressing voltage signal so as to avoid the 4th too high resistance of voltage signal, the 4th resistance
It is series between the signal output part of conversion chip and the detection pin of main control chip.
Further, in addition to voltage clamping circuit, voltage clamping circuit is arranged between the 4th resistance and main control chip, electricity
Pressing clamp circuit includes diode and the 4th electric capacity, and the positive pole of diode and the 4th capacitance connection are together with and are connected to the simultaneously
Between four resistance and main control chip, negative pole and the bias voltage of diode are connected together, the other end ground connection of the 4th electric capacity.
Further, bias voltage is 5V.
Further, the model LM358 of conversion chip.
The beneficial effects of the utility model are：Low-cost electric current detection circuit, due to the electric current by constantan wire be difficult by
The influence of external force and change, therefore the medium detected by the use of constantan wire as current signal can obtain the inspection of accurate electric current
Measured value, is not in the situation for detecting that electric current is inaccurate so as to ensure the current signal stable by constantan wire, and by
In the cost of constantan wire is low, small volume, therefore, it is possible to improve the processing efficiency of detection circuit, reduce the area of detection circuit, from
And effectively reduce the cost of detection circuit；Conversion chip and the first electric capacity of its periphery, the second electric capacity, the 3rd electric capacity, the first electricity
Resistance, second resistance and 3rd resistor cooperate so that be converted into voltage signal by the current signal for flowing through constantan wire, so as to
Enough by main control chip effective detection, therefore, it is possible to accurately measure the current signal value for flowing through constantan wire；4th resistance can rise
To the effect for suppressing voltage signal peak value so that the voltage signal exported by conversion chip, which is in, can be received the scope of detection
Within, cause the inaccurate situation for even burning out main control chip of detection so as to avoid voltage signal peak value too high；By two poles
The voltage signal values for being output to main control chip can be limited in bias voltage by the voltage clamping circuit that pipe and the 4th electric capacity are constituted
Within the scope of so that the voltage of detection circuit can be balanced, and limit the voltage signal for being output to main control chip
It is worth the magnitude of voltage range of receiving not over main control chip, so as to the situation for avoiding main control chip from being burned out；Magnitude of voltage is
5V bias voltage is consistent with the supply voltage of conversion chip, enables to the magnitude of voltage of whole detection circuit to be balanced, and
And the power supply for additionally supplying bias voltage can also be saved, so as to play reduction detection circuit area and reduction detection circuit cost
Effect；The model LM358 of conversion chip, effectively can be converted into the current signal for flowing through constantan wire measuring
Voltage signal, so as to ensure that the good detection to current signal.
Brief description of the drawings
The utility model is described in further detail with example below in conjunction with the accompanying drawings.
Fig. 1 is the circuit theory diagrams of the utility model Low-cost electric current detection circuit.
Embodiment
Reference picture 1, Low-cost electric current detection circuit of the present utility model, including for exporting the electric current of current signal to be measured
Output terminals A CN1, current reflux end ACN2, the constantan for gathering current signal for making current signal to be measured be flowed back
Silk J5, the conversion chip U1 for the current signal by constantan wire J5 being converted into voltage signal and for according to being converted to
Voltage signal judge sensed current signal size main control chip U2, conversion chip U1 periphery includes being used to improve steady
Qualitatively the first electric capacity C10, the second electric capacity C33 and the 3rd electric capacity C35, conversion chip U1 periphery also include flowing through health for handle
Copper wire J5 current signal is converted to the first resistor R31, second resistance R32 and 3rd resistor R34 of voltage signal, 3rd resistor
R34 is series between current output terminal ACN1 and conversion chip U1 signal input negative terminal 2, and conversion chip U1 signal input is just
End 3 is connected together with current reflux end ACN2, and constantan wire J5 two ends are connected to current output terminal ACN1 and electric current is returned
Flow end ACN2, second resistance R32 and the second electric capacity C33 is parallel to together and two tie point is connected to conversion chip
U1 signal output part 1 and signal input negative terminal 2, the signal that first resistor R31 two ends are connected to conversion chip U1 is defeated
Go out end 1 and signal input positive terminal 3, the first electric capacity C10 two ends are connected to bias voltage and conversion chip U1 signal is defeated
Enter anode 3, the 3rd electric capacity C35 two ends are connected to reference ground and conversion chip U1 signal input negative terminal 2, change core
The detection pin SEN of piece U1 signal output part 1 and main control chip U2 is connected together, wherein, in addition to voltage clamping circuit,
Voltage clamping circuit is arranged between the 4th resistance R36 and main control chip U2, and voltage clamping circuit includes diode D1 and the 4th
Electric capacity C23, diode D1 positive pole and the 4th electric capacity C23 are connected together and while are connected to the 4th resistance R36 and master control core
Between piece U2, diode D1 negative pole and bias voltage are connected together, the 4th electric capacity C23 other end ground connection.When no electricity
When stream flows through constantan wire J5, conversion chip U1 is not changed to any current signal, therefore conversion chip U1 does not have voltage
Signal output, but because voltage clamping circuit has been limited in the magnitude of voltage for being transferred to main control chip U2 the scope of bias voltage
It is interior, therefore main control chip U2 can receive the sine wave-shaped signal that a peak value is bias voltage value, therefore main control chip U2
It can be handled according to the peak value for the sine wave-shaped signal of bias voltage value and obtain a stable normalized current conversion value；When having
When electric current flows through constantan wire J5, in conversion chip U1 and first resistor R31, second resistance R32 and 3rd resistor R34 cooperation
Under effect, the voltage signal of conversion chip U1 outputs disclosure satisfy that following equation：
VF=bias voltage-Ia*RJ5*R32/R34
Wherein, VF is to be transferred to the voltage signal values that main control chip U2 is detected, Ia is the electric current for flowing through constantan wire J5
Signal value, RJ5For constantan wire J5 resistance value, R32For second resistance R32 resistance value, R34For 3rd resistor R34 resistance value；
Another K=RJ5*R32/R34, wherein K is a positive number, therefore can be obtained：
VF=bias voltage-Ia*K
From above formula, when the current signal for flowing through constantan wire J5 is bigger, what is obtained is transferred to main control chip U2 progress
The voltage signal values VF of detection is smaller, therefore, and now main control chip U2 receives the sine wave that a peak value is less than bias voltage
Signal, and it is smaller to flow through the peak value for the voltage signal that constantan wire J5 current signal is bigger, and main control chip U2 is received, therefore
Main control chip U2 can according to the peak value of the voltage signal difference and judge flow through constantan wire J5 current signal size, from
And the accurate detection of current signal is ensure that, and because constantan wire J5 cost is low, small volume, therefore, it is possible to improve detection
The processing efficiency of circuit, reduces the area of detection circuit, so that the effectively cost of reduction detection circuit.
Wherein, reference picture 1, for suppressing voltage signal so as to avoid the 4th too high resistance R36 of voltage signal, is series at
Between conversion chip U1 signal output part 1 and main control chip U2 detection pin SEN.4th resistance R36 can play suppression
The effect of voltage signal peak value so that the voltage signal exported by conversion chip U1 be in can be received detection scope it
It is interior, cause the inaccurate situation for even burning out main control chip U2 of detection so as to avoid voltage signal peak value too high.
Wherein, reference picture 1, bias voltage is 5V, conversion chip U1 model LM358.Magnitude of voltage is 5V biased electrical
Pressure is consistent with conversion chip U1 supply voltage, enables to the magnitude of voltage of whole detection circuit to be balanced, and can also
The power supply for additionally supplying bias voltage is saved, so that play a part of reducing detection circuit area and reduction detection circuit cost,
And because bias voltage is 5V, therefore it is updated among above formula, can obtained：
VF=5- Ia*K
Therefore when no electric current flows through constantan wire J5, main control chip U2 can receive the sine wave that a peak value is 5V
Shape signal；When there is electric current to flow through constantan wire J5, main control chip U2, which can receive sinusoidal waveform of the peak value less than 5V, to be believed
Number.It is less than or equal to 5V voltage signal because main control chip U2 can generally receive peak value, therefore ensure that main control chip
U2 can be detected accurately and effectively to the current signal for flowing through constantan wire J5.Conversion chip U1 model LM358, can
Effectively the current signal for flowing through constantan wire J5 is converted into the voltage signal that can be measured, so as to ensure that to current signal
Good detection.
Above is to it is of the present utility model it is preferable implementation illustrated, but the utility model be not limited to it is above-mentioned
Embodiment, those skilled in the art can also make a variety of be equal on the premise of without prejudice to the utility model spirit
Deformation is replaced, and these equivalent deformations or replacement are all contained in the application claim limited range.
Claims (5)
1. Low-cost electric current detection circuit, it is characterised in that：Including the current output terminal for exporting current signal to be measured
（ACN1）, current reflux end for making current signal to be measured be flowed back（ACN2）, constantan wire for gathering current signal
（J5）, for pass through the constantan wire（J5）Current signal be converted into the conversion chip of voltage signal（U1）With for basis
The voltage signal being converted to judges the main control chip of the size of sensed current signal（U2）, the conversion chip（U1）It is outer
Enclose including the first electric capacity for improving stability（C10）, the second electric capacity（C33）With the 3rd electric capacity（C35）, the conversion chip
（U1）Periphery also include being used for flowing through the constantan wire（J5）Current signal be converted to the first resistor of voltage signal
（R31）, second resistance（R32）And 3rd resistor（R34）, the 3rd resistor（R34）It is series at the current output terminal
（ACN1）With conversion chip（U1）Signal input negative terminal（2）Between, the conversion chip（U1）Signal input positive terminal（3）With
The current reflux end（ACN2）It is connected together, the constantan wire（J5）Two ends be connected to the current output terminal
（ACN1）With current reflux end（ACN2）, the second resistance（R32）With the second electric capacity（C33）Be parallel to together and two
Tie point is connected to the conversion chip（U1）Signal output part（1）With signal input negative terminal（2）, the first resistor
（R31）Two ends be connected to the conversion chip（U1）Signal output part（1）With signal input positive terminal（3）, described
One electric capacity（C10）Two ends be connected to bias voltage and the conversion chip（U1）Signal input positive terminal（3）, described
Three electric capacity（C35）Two ends be connected to reference ground and the conversion chip（U1）Signal input negative terminal（2）, described turn
Change chip（U1）Signal output part（1）With the main control chip（U2）Detection pin（SEN）It is connected together.
2. Low-cost electric current detection circuit according to claim 1, it is characterised in that：Also include being used to suppress voltage signal
So as to avoid the 4th too high resistance of voltage signal（R36）, the 4th resistance（R36）It is series at the conversion chip（U1）'s
Signal output part（1）With the main control chip（U2）Detection pin（SEN）Between.
3. Low-cost electric current detection circuit according to claim 2, it is characterised in that：Also include voltage clamping circuit, institute
State voltage clamping circuit and be arranged at the 4th resistance（R36）And main control chip（U2）Between, the voltage clamping circuit includes
Diode（D1）With the 4th electric capacity（C23）, the diode（D1）Positive pole and the 4th electric capacity（C23）It is connected together simultaneously
It is connected to the 4th resistance simultaneously（R36）And main control chip（U2）Between, the diode（D1）Negative pole and the biasing
Voltage is connected together, the 4th electric capacity（C23）The other end ground connection.
4. Low-cost electric current detection circuit according to claim 3, it is characterised in that：The bias voltage is 5V.
5. Low-cost electric current detection circuit according to claim 2, it is characterised in that：The conversion chip（U1）Model
For LM358.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720014039.8U CN206348387U (en) | 2017-01-05 | 2017-01-05 | Low-cost electric current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720014039.8U CN206348387U (en) | 2017-01-05 | 2017-01-05 | Low-cost electric current detection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN206348387U true CN206348387U (en) | 2017-07-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720014039.8U Active CN206348387U (en) | 2017-01-05 | 2017-01-05 | Low-cost electric current detection circuit |
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| Country | Link |
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| CN (1) | CN206348387U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112666378A (en) * | 2020-12-31 | 2021-04-16 | 深圳市云鼠科技开发有限公司 | Current detection amplifying circuit |
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2017
- 2017-01-05 CN CN201720014039.8U patent/CN206348387U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112666378A (en) * | 2020-12-31 | 2021-04-16 | 深圳市云鼠科技开发有限公司 | Current detection amplifying circuit |
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