CN203759112U - High-frequency current detection circuit - Google Patents
High-frequency current detection circuit Download PDFInfo
- Publication number
- CN203759112U CN203759112U CN201420150350.1U CN201420150350U CN203759112U CN 203759112 U CN203759112 U CN 203759112U CN 201420150350 U CN201420150350 U CN 201420150350U CN 203759112 U CN203759112 U CN 203759112U
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- China
- Prior art keywords
- diode
- resistance
- circuit
- operational amplifier
- frequency current
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- Expired - Lifetime
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- 238000001514 detection method Methods 0.000 title abstract description 14
- 238000006243 chemical reaction Methods 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 description 6
- 238000007689 inspection Methods 0.000 description 6
- 238000001914 filtration Methods 0.000 description 4
- 238000005070 sampling Methods 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000009527 percussion Methods 0.000 description 1
Abstract
The utility model discloses a high-frequency current detection circuit and relates to the field of current detection. The high-frequency current detection circuit comprises a current reducing circuit, a bridge rectifier circuit, and an amplifier circuit; the current reducing circuit is mainly composed of a transformer; the bridge rectifier circuit is mainly composed of a diode; the amplifier circuit is mainly composed of an integrated operational amplifier. High current to be detected is reduced and converted into voltage amplified and filtered, and the voltage is detected and used for indicating the high current to be detected; by the use of the high-frequency current detection circuit, the problems that current detection range is limited and detection precision is low during detecting of high current of the traditional circuit are solved.
Description
Technical field
The utility model relates to current detection circuit, relates in particular to a kind of checking of great current circuit.
Background technology
In prior art, more conventional current detection circuit is that inspection leakage resistance is connected in the loop at sensed current place, examines the voltage at leakage resistance two ends determine sensed current by detection.As shown in Figure 1, for detecting the tested electric current I of the load of flowing through, inspection leakage resistance R is connected in the loop at load place, sensed current I flows through equally and examines leakage resistance R, detect the voltage U at resistance R two ends by measurement, because the resistance of detection resistance R is known, can draw the size of sensed current I according to Ohm law, I=U/R.
Ensureing that Power supply in the situation that, the scope that prior art detects electric current is still restricted, and precision is not high yet while detecting large electric current; Meanwhile, inspection leakage resistance R has the restriction of rated power, exceedes certain power, and inspection leakage resistance R is with regard to cisco unity malfunction, and therefore the restriction of the rated power of resistance also makes to use inspection leakage resistance to be restricted in the application of measuring large electric current.
Summary of the invention
The purpose of this utility model is when leakage resistance is measured large electric current, to examine leakage resistance resistance and be subject to the impact of discrete parameter and cause the measured poor problem of large current accuracy in order to solve to examine in prior art, and proposes a kind of high-frequency current testing circuit; This high-frequency current testing circuit has solved and when traditional circuit detects large electric current, has detected the limited and not high problem of accuracy of detection of range of current.
The technical solution of the utility model is as follows:
High-frequency current testing circuit of the present utility model, comprises that an electric current of mainly being realized by transformer dwindles circuit, a bridge rectifier circuit of mainly being realized by diode and an amplifying circuit of mainly being realized by integrated operational amplifier.
Particularly, bridge rectifier circuit: one end of the 3rd resistance connects power supply VCC, four articles of branch roads of other end access: Article 1 branch road is the series circuit of the first diode and the 3rd diode composition, wherein the negative pole of the first diode connects described the 3rd resistance, the anodal negative pole that connects the 3rd diode, the plus earth of the 3rd diode; Article 2 branch road is the series circuit of the second diode and the 4th diode composition, and wherein the negative pole of the second diode connects described the 3rd resistance, the anodal negative pole that connects the 4th diode, the plus earth of the 4th diode; Article 3 branch road is the 6th resistance of a ground connection; Article 4 branch road is second resistance, this second resistance the other end be connected with the in-phase input end of an integrated operational amplifier.
Electric current dwindles circuit: the primary coil of pull-up resistor two ends and a transformer is connected to form loop, and secondary coil one end of this transformer is connected with the positive pole of described the first diode, and the other end is connected with the positive pole of described the second diode.
Amplifying circuit: the inverting input of described integrated operational amplifier is connected with one end of the 5th resistance, this end of the 5th resistance is also and between the output terminal of described integrated operational amplifier, be connected to a parallel circuit being made up of the 4th resistance and the 5th electric capacity; The other end ground connection of the 5th resistance.
One end of the first resistance is connected with the output terminal of described integrated operational amplifier, and the other end is linked into the AD conversion mouthful of MCU.
More preferably, above-mentioned high-frequency current testing circuit, one end of the AD conversion mouth of its first resistance access MCU is also connected with the first electric capacity of a ground connection.
More preferably, above-mentioned high-frequency current testing circuit, one end that its second resistance accesses the in-phase input end of described integrated operational amplifier is also connected with the 4th electric capacity of a ground connection.
More preferably, above-mentioned high-frequency current testing circuit, its integrated operational amplifier adopts symmetric double Power supply mode, the stabilized voltage supply of its positive supply termination+15V, the stabilized voltage supply of negative supply termination-15V.
More preferably, above-mentioned high-frequency current testing circuit, the stabilized voltage supply of connect+15V of its integrated operational amplifier positive power source terminal is also connected with the second electric capacity of a ground connection, and the stabilized voltage supply of connect-15V of negative power end is also connected with the 3rd electric capacity of a ground connection.
More preferably, above-mentioned high-frequency current testing circuit, also comprises a two-diode clamp circuit, and this two-diode clamp circuit is made up of the 5th diode and the 6th diode; The wherein plus earth of the 5th diode, negative pole connects the positive pole of the 6th diode; The positive pole of the 6th diode is also connected with one end of the AD conversion of described the first resistance access MCU mouthful; The negative pole of the 6th diode is connected with described power supply VCC.
More preferably, above-mentioned high-frequency current testing circuit, described transformer is high-frequency transformer.
The beneficial effects of the utility model:
1, high-frequency current testing circuit of the present utility model, filter capacitor comprises the first electric capacity, the 3rd electric capacity and the 4th electric capacity, plays the slow effect starting, and filtering high-frequency percussion electric current or undesired signal, eliminate the impact of these signals on measuring accuracy, improve measuring accuracy.
2, high-frequency current testing circuit of the present utility model, adopt high-frequency transformer when mutual inductor use, the former secondary turn ratio of detected electric current and high-frequency transformer is inversely proportional to, the turn ratio is less, electric current that can be tested is just larger, and this is not restricted this high-frequency current testing circuit in the application of measuring large electric current.
Brief description of the drawings
Fig. 1 uses inspection leakage resistance to detect the circuit diagram of electric current in prior art;
Fig. 2 is high-frequency current testing circuit figure of the present utility model.
Embodiment
Now to be described further the utility model with accompanying drawing in order better illustrating in conjunction with the embodiments, to should be appreciated that specific embodiment described herein is only in order to explain the utility model, and be not used in restriction high-frequency current testing circuit of the present utility model.
Be illustrated in figure 2 high-frequency current testing circuit of the present utility model, comprise that an electric current of mainly being realized by transformer dwindles circuit, a bridge rectifier circuit of mainly being realized by diode and an amplifying circuit of mainly being realized by integrated operational amplifier.
Electric current dwindles circuit:
The device of realizing electric current reduction capability is the transformer BT1 in Fig. 2, and the turn ratio of its primary coil and secondary coil is N
1/ N
2; On primary coil, be connected to pull-up resistor R, might as well establish the detected electric current of need of flowing through on pull-up resistor R is I
1, the electric current I on transformer BT1 secondary
2=(N
1/ N
2) * I
1; As the turn ratio N of former secondary
1/ N
2be less than at 1 o'clock, can realize electric current reduction capability.
Compare pull-up resistor R, transformer BT1 is especially in the time that BT1 is high-frequency transformer, and the rated power of its secondary coil can be very large, can be applicable to the detection occasion in the time that power is very large.
Bridge rectifier circuit:
High-frequency current testing circuit of the present utility model rectification circuit used is,---the first diode DS1, the second diode DS2, the 3rd diode DS3 and the 4th diode DS4---classical bridge rectifier electric current of formation by four diodes.Particularly, one end of the 3rd resistance R 3 connects power supply VCC, four articles of branch roads of other end access: Article 1 branch road is the series circuit of the first diode DS1 and the 3rd diode DS3 composition, wherein the negative pole of the first diode DS1 connects described the 3rd resistance R 3, the anodal negative pole that connects the 3rd diode DS3, the plus earth of the 3rd diode DS3; Article 2 branch road is the series circuit of the second diode DS2 and the 4th diode DS4 composition, and wherein the negative pole of the second diode DS2 connects described the 3rd resistance R 3, the anodal negative pole that connects the 4th diode DS4, the plus earth of the 4th diode DS4; Article 3 branch road is the 6th resistance R 6 of a ground connection; Article 4 branch road is second resistance R 2, this second resistance R 2 the other end be connected with the in-phase input end of integrated operational amplifier IC1A.
The secondary access bridge rectifier circuit that above-mentioned electric current is dwindled to the transformer BT1 in circuit, secondary coil one end of this transformer BT1 is connected with the positive pole of the first diode DS1 in bridge rectifier circuit, and the other end is connected with the positive pole of the second diode DS2.
Therefore, the electric current of inflow bridge rectifier circuit is I
2; Electric current I
2after bridge rectifier, access the 6th resistance R 6 of sample, realize by detecting the voltage of the 6th resistance R 6 object that detects electric current.The second resistance R 2 is current-limiting resistances, therefore U
2=U
1=R6*I
2=R6* (N
1/ N
2) * I
1; Wherein, as shown in Figure 2, U
1, U
2there is respectively the voltage-to-ground of the 3rd resistance R 3, the second resistance R 2 left ends.
Electric current through the 6th resistance R 6 of over-sampling is little current signal, compares the large current signal that detects pull-up resistor R, and the resistor power of the 6th resistance R 6 of sampling is low, has greatly improved accuracy of detection.
Amplifying circuit:
Above-mentioned voltage signal U
1after the second resistance R 2 of current limliting, connect the 4th capacitor C 4, the second resistance R 2 of filtering of a ground connection and the 4th capacitor C 4 to voltage signal U
1form capacitance-resistance filter, obtain voltage signal U
2.Voltage signal U
2be connected to the in-phase input end of integrated operational amplifier IC1A, because the inverting input of this integrated operational amplifier IC1A is connected with one end of the 5th resistance R 5, this end of the 5th resistance R 5 also and between the output terminal of described integrated operational amplifier IC1A, be connected to a parallel circuit being made up of the 4th resistance R 4 and the 5th capacitor C 5, the other end ground connection of the 5th resistance R 5, therefore voltage signal U
2obtain voltage signal U through operational amplification circuit active power filtering and homophase amplification---enlargement factor K=(1+R4/R5)---
3, the voltage signal U after amplification
3the first capacitor C 1, the first resistance R 1 and the first capacitor C 1 that after the first resistance R 1 of current limliting, connect the filtering of a ground connection form capacitance-resistance filter to voltage signal U3, thereby obtain voltage signal U
4, wherein U
4=U
3=K*U
2=(1+R4/R5) * R6* (N
1/ N
2) * I
1; Wherein, as shown in Figure 2, U
3, U
4be respectively the output terminal of integrated operational amplifier IC1A, the voltage-to-ground of the first resistance R 1 left end.In addition, integrated operational amplifier IC1A adopts symmetric double Power supply mode, the stabilized voltage supply of its positive supply termination+15V, the stabilized voltage supply of negative supply termination-15V; The stabilized voltage supply of connect+15V of the positive power source terminal of integrated operational amplifier IC1A is also connected with the second electric capacity of a ground connection, and the stabilized voltage supply of connect-15V of negative power end is also connected with the 3rd electric capacity of a ground connection.
Voltage signal U4 meets a two-diode clamp circuit DA1, and this clamping circuit DA1 is made up of the 5th diode and the 6th diode; The wherein plus earth of the 5th diode, negative pole connects the positive pole of the 6th diode; The positive pole of the 6th diode is also connected with one end of the AD conversion of described the first resistance access MCU mouthful; The negative pole of the 6th diode is connected with described power supply VCC.The function of clamping circuit DA1 is for working as voltage signal U
4while exceeding VCC, by U
4voltage clamping be: the pressure drop of VCC+DA1, as voltage signal U
4voltage during lower than GND, by U
4voltage clamping be: the pressure drop of negative DA1.The object of this clamping circuit DA1 is to protect the AD conversion mouthful of following MCU.
By voltage signal U
4be connected to the AD conversion mouthful of MCU, by AD converse routine by analog quantity voltage signal U
4convert digital quantity to and carry out computing, calculate the electric current I that needs survey
1value:
I
1=N
2*R5*U
4/(N
1*R6*(R4+R5))；
From above formula, need the electric current I of surveying
1size and the turn ratio N of high-frequency transformer BT1
1/ N
2be inversely proportional to, be inversely proportional to the 6th resistance R 6 of sampling.While detecting the electric current of different sizes, change the turn ratio N of high-frequency transformer
1/ N
2just can realize with the 6th resistance R 6 of sampling.
From the above, voltage signal U
4value characterized and needed the electric current I that detects
1so the high-frequency current testing circuit that the utility model provides can detect the electric current I on pull-up resistor R
1.
Claims (7)
1. a high-frequency current testing circuit, is characterized in that:
Comprise that an electric current of mainly being realized by transformer dwindles circuit, a bridge rectifier circuit of mainly being realized by diode and an amplifying circuit of mainly being realized by integrated operational amplifier;
Bridge rectifier circuit: one end of the 3rd resistance connects power supply VCC, four articles of branch roads of other end access: Article 1 branch road is the series circuit of the first diode and the 3rd diode composition, wherein the negative pole of the first diode connects described the 3rd resistance, the anodal negative pole that connects the 3rd diode, the plus earth of the 3rd diode; Article 2 branch road is the series circuit of the second diode and the 4th diode composition, and wherein the negative pole of the second diode connects described the 3rd resistance, the anodal negative pole that connects the 4th diode, the plus earth of the 4th diode; Article 3 branch road is the 6th resistance of a ground connection; Article 4 branch road is second resistance, this second resistance the other end be connected with the in-phase input end of an integrated operational amplifier;
Electric current dwindles circuit: the primary coil of pull-up resistor two ends and a transformer is connected to form loop, and secondary coil one end of this transformer is connected with the positive pole of described the first diode, and the other end is connected with the positive pole of described the second diode;
Amplifying circuit: the inverting input of described integrated operational amplifier is connected with one end of the 5th resistance, this end of the 5th resistance is also and between the output terminal of described integrated operational amplifier, be connected to a parallel circuit being made up of the 4th resistance and the 5th electric capacity; The other end ground connection of the 5th resistance;
One end of the first resistance is connected with the output terminal of described integrated operational amplifier, and the other end is linked into the AD conversion mouthful of MCU.
2. high-frequency current testing circuit as claimed in claim 1, is characterized in that: one end of the AD conversion mouth of described the first resistance access MCU is also connected with the first electric capacity of a ground connection.
3. high-frequency current testing circuit as claimed in claim 1, is characterized in that: one end that described the second resistance accesses the in-phase input end of described integrated operational amplifier is also connected with the 4th electric capacity of a ground connection.
4. high-frequency current testing circuit as claimed in claim 1, is characterized in that: described integrated operational amplifier adopts symmetric double Power supply mode, the stabilized voltage supply of its positive supply termination+15V, the stabilized voltage supply of negative supply termination-15V.
5. the high-frequency current testing circuit as described in claim 1 or 4, it is characterized in that: the stabilized voltage supply of connect+15V of described integrated operational amplifier positive power source terminal is also connected with the second electric capacity of a ground connection, the stabilized voltage supply of connect-15V of negative power end is also connected with the 3rd electric capacity of a ground connection.
6. high-frequency current testing circuit as claimed in claim 1, is characterized in that: also comprise a two-diode clamp circuit, this two-diode clamp circuit is made up of the 5th diode and the 6th diode; The wherein plus earth of the 5th diode, negative pole connects the positive pole of the 6th diode; The positive pole of the 6th diode is also connected with one end of the AD conversion of described the first resistance access MCU mouthful; The negative pole of the 6th diode is connected with described power supply VCC.
7. high-frequency current testing circuit as claimed in claim 1, is characterized in that: described transformer is high-frequency transformer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420150350.1U CN203759112U (en) | 2014-03-31 | 2014-03-31 | High-frequency current detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420150350.1U CN203759112U (en) | 2014-03-31 | 2014-03-31 | High-frequency current detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203759112U true CN203759112U (en) | 2014-08-06 |
Family
ID=51254368
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420150350.1U Expired - Lifetime CN203759112U (en) | 2014-03-31 | 2014-03-31 | High-frequency current detection circuit |
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| Country | Link |
|---|---|
| CN (1) | CN203759112U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104991107A (en) * | 2015-07-31 | 2015-10-21 | 苏州华电电气股份有限公司 | Measurement device of power grid primary current and method thereof |
| CN106026532A (en) * | 2016-06-22 | 2016-10-12 | 宁波兴泰科技有限公司 | Position signal input module of servo motor |
| CN111342649A (en) * | 2020-03-21 | 2020-06-26 | 安徽兆立普医疗器械有限公司 | Oscillation current output and feedback circuit of high-frequency oscillation thermotherapy rehabilitation instrument |
| CN113614548A (en) * | 2019-03-29 | 2021-11-05 | 英福康有限责任公司 | Amplifier arrangement for amplifying a current |
| CN114221527A (en) * | 2022-02-22 | 2022-03-22 | 深圳市深澳视觉科技有限公司 | Alternating current-direct current energy conversion control circuit and high-frequency medical equipment |
-
2014
- 2014-03-31 CN CN201420150350.1U patent/CN203759112U/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104991107A (en) * | 2015-07-31 | 2015-10-21 | 苏州华电电气股份有限公司 | Measurement device of power grid primary current and method thereof |
| CN106026532A (en) * | 2016-06-22 | 2016-10-12 | 宁波兴泰科技有限公司 | Position signal input module of servo motor |
| CN106026532B (en) * | 2016-06-22 | 2018-12-04 | 宁波兴泰科技有限公司 | The position signal input module of servo motor |
| CN113614548A (en) * | 2019-03-29 | 2021-11-05 | 英福康有限责任公司 | Amplifier arrangement for amplifying a current |
| CN113614548B (en) * | 2019-03-29 | 2024-02-20 | 英福康有限责任公司 | Amplifier device for amplifying small currents |
| CN111342649A (en) * | 2020-03-21 | 2020-06-26 | 安徽兆立普医疗器械有限公司 | Oscillation current output and feedback circuit of high-frequency oscillation thermotherapy rehabilitation instrument |
| CN114221527A (en) * | 2022-02-22 | 2022-03-22 | 深圳市深澳视觉科技有限公司 | Alternating current-direct current energy conversion control circuit and high-frequency medical equipment |
| CN114221527B (en) * | 2022-02-22 | 2022-05-20 | 深圳市深澳视觉科技有限公司 | Alternating current-direct current energy conversion control circuit and high-frequency medical equipment |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C53 | Correction of patent of invention or patent application | ||
| CB03 | Change of inventor or designer information |
Inventor after: Cong Xiaoliang Inventor before: Jiang Haifeng Inventor before: Luo Jianbin |
|
| COR | Change of bibliographic data |
Free format text: CORRECT: INVENTOR; FROM: JIANG HAIFENG LUO JIANBIN TO: CONG XIAOLIANG |
|
| CX01 | Expiry of patent term |
Granted publication date: 20140806 |