CN201955374U - Micro current detection and amplification device - Google Patents
Micro current detection and amplification device Download PDFInfo
- Publication number
- CN201955374U CN201955374U CN2010206351013U CN201020635101U CN201955374U CN 201955374 U CN201955374 U CN 201955374U CN 2010206351013 U CN2010206351013 U CN 2010206351013U CN 201020635101 U CN201020635101 U CN 201020635101U CN 201955374 U CN201955374 U CN 201955374U
- Authority
- CN
- China
- Prior art keywords
- circuit
- operational amplifier
- limiter
- filtering
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Amplifiers (AREA)
Abstract
The utility model discloses a micro current detection and amplification device, which comprises a sampling circuit, an MCU (microprogrammed control unit) control circuit used for controlling sampling voltage, and an amplification circuit used for amplifying the sampling voltage output by the sampling circuit, wherein a filtering limiter circuit is connected between the sampling circuit and the amplification circuit; the amplification circuit comprises a first amplification circuit and a second amplification circuit; the filtering limiter circuit comprises a first filtering limiter circuit and the second filtering limiter circuit; under the control of the MCU control circuit, a first way sampling voltage output by the sampling circuit is subjected to amplitude limiting and filtration by the first filtering limiter circuit, and then is input to the first amplification circuit for amplification; and under the control of the MCU control circuit, a second way sampling voltage is subjected to amplitude limiting and filtration by the second filtering limiter circuit, and then is input to the second amplification circuit for amplification. The micro current detection and amplification device can be used for accurate sampling, has adjustable magnification ratio, is simple and easy to realize, and has the advantages of simple circuit, reasonable design, strong practicability and high anti-interference performance; and the use and the operation are much simplified.
Description
Technical field
The present invention relates to a kind of little current detecting multiplying arrangement.
Technical background
Little electric current is more and more frequent in daily detection is handled, this just need amplify the detection of little electric current. but common amplifier can not use, even because their input offset voltage is more than hundreds of microvolts. be enough to flood signal. offset voltage can return to zero, but drift is to be difficult to eliminate, so need special circuit for the detection amplification of little electric current.
Summary of the invention
For overcoming above technological deficiency, it is simple to the invention provides a kind of circuit, reasonable in design, practical, uses simplified control, little current detecting multiplying arrangement of strong interference immunity.
For achieving the above object, concrete technical scheme is:
A kind of little current detecting multiplying arrangement of the present invention, comprise sample circuit, the MCU control circuit of control sampled voltage size, and the amplifying circuit that the sampled voltage of sample circuit output is amplified, also be connected with the filtering amplitude limiter circuit between sample circuit and the amplifying circuit, described amplifying circuit comprises first amplifying circuit and second amplifying circuit, the filtering amplitude limiter circuit comprises the first filtering amplitude limiter circuit and the second filtering amplitude limiter circuit, the first via sampled voltage of MCU control circuit control sample circuit output through the first filtering amplitude limiter circuit limit filtration after input first amplifying circuit amplify; The second road sampled voltage of MCU control circuit control sample circuit output through the second filtering amplitude limiter circuit limit filtration after input second amplifying circuit amplify.
Further, described sample circuit comprises sampling resistor, triode and relay, sampling resistor R124 and R126 series connection, sampling resistor R126 two ends relay K 303 in parallel, the base stage control end SWICH mouth of triode V230 is connected to the MCU control circuit, and the MCU control circuit is realized relay K 303 is disconnected and closed control by the control to the SWICH mouth; First via sampled voltage is the R124 terminal voltage when relay K 303 closures, and when relay K 303 disconnected, the second road sampled voltage was R124, voltage sum on R126 two resistance.
Further, described first amplifying circuit comprises the first operational amplifier N241 and first feedback circuit, described first feedback circuit comprises potentiometer RW204 and resistance R 249,6 pin of the first operational amplifier N241 meet potentiometer RW204, draw the back and form feedback circuit with the negative pole input port that resistance R 249 is connected in series to the first operational amplifier N241; Second amplifying circuit comprises the second operational amplifier N242 and second feedback circuit, described second feedback circuit comprises potentiometer RW205 and resistance R 252,6 pin of the second operational amplifier N242 meet potentiometer RW205, draw the back and form feedback circuit with negative pole input port 2 pin that resistance R 252 is connected in series to the second operational amplifier N242.
Further, the first filtering amplitude limiter circuit comprises limiter tube V246, V250 and capacitor C 243, C247, the negative electrode of the anode of limiter tube V246 and limiter tube V250 is connected to the 3 end input ports of sample circuit and operational amplifier N241, the anode of the negative electrode of limiter tube V246 and limiter tube V250 is connected ground, and the 3 end input port voltages of the first operational amplifier N241 are carried out amplitude limit. and capacitor C 243 and C247 are connected on the 3 end input ports of the first operational amplifier N241 and voltage is waited to amplify in ground with the filtering first operational amplifier N241 input end noise; The second filtering amplitude limiter circuit comprises limiter tube V251, V252 and capacitor C 244, C248, the negative electrode of the anode of limiter tube V251 and limiter tube V252 is connected to the 3 end input ports of the sample circuit and the second operational amplifier N242, the anode of the negative electrode of limiter tube V251 and limiter tube V252 is connected ground, 3 end input port voltages to the second operational amplifier N242 carry out amplitude limit, and capacitor C 244 and C248 are connected on the 3 end input ports of the second operational amplifier N242 and voltage is waited to amplify in ground with the filtering second operational amplifier N242 input end noise.
Further, the described second operational amplifier N242 adopts the chopper-zero-stabilized type amplifier TLC2652CP of low maladjustment voltage drift; The described first operational amplifier N241 adopts the non-chopper-zero-stabilized type amplifier OP-07 of low maladjustment voltage drift.
The present invention with respect to the beneficial effect of prior art is:
Be the circuit of major programme with the steady zero property operational amplifier TLC2652CP of high-precision and low-offset voltage chopping, precision resistance among the present invention, MCU realizes the two-way resistance sampling to relay on-off, obtains the two-way sampled voltage.Sampling accurately is input to respectively that operational amplifier amplifies with different enlargement factors and handles through diode limiting, electric capacity filter out noise the two-way sampled voltage.Enlargement factor of the present invention is adjustable, simply is easy to realize.
Description of drawings
Fig. 1 is the block diagram of the little current detecting multiplying arrangement of the present invention;
Fig. 2 is a sample circuit device composition diagram of the present invention;
Fig. 3 is amplifying circuit of the present invention and filtering amplitude limiter circuit device composition diagram.
Embodiment
Referring to Fig. 1, the block diagram of the little current detecting multiplying arrangement of the present invention, comprise sample circuit 3, the MCU control circuit 4 of control sampled voltage size, and the amplifying circuit that the sampled voltage of sample circuit output is amplified, wherein also be connected with the filtering amplitude limiter circuit between sample circuit and the amplifying circuit, amplifying circuit comprises first amplifying circuit 11 and second amplifying circuit 12, the filtering amplitude limiter circuit comprises the first filtering amplitude limiter circuit 21 and the second filtering amplitude limiter circuit 22, the first via sampled voltage of MCU control circuit 4 control sample circuits 3 outputs through the first filtering amplitude limiter circuit, 21 limit filtrations after input first amplifying circuit 11 amplify; The second road sampled voltage of MCU control circuit 4 control sample circuits 3 outputs through the second filtering amplitude limiter circuit, 22 limit filtrations after input second amplifying circuit 12 amplify.
The sample circuit device is formed as Fig. 2, sample circuit comprises sampling resistor, triode and relay, sampling resistor R124 and R126 series connection, sampling resistor R126 two ends relay K 303 in parallel, the base stage control end SWICH mouth of triode V230 is connected to MCU control circuit 4, and MCU control circuit 4 is realized relay K 303 is disconnected and closed control by the control to the SWICH mouth; First via sampled voltage is the R124 terminal voltage when relay K 303 closures, and when relay K 303 disconnected, the second road sampled voltage was R124, voltage sum on R126 two resistance.
Little current amplification circuit and filtering amplitude limiter circuit device are formed as shown in Figure 3, first amplifying circuit 11 comprises the first operational amplifier N241 and first feedback circuit, described first feedback circuit comprises potentiometer RW204 and resistance R 249,6 pin of the first operational amplifier N241 meet potentiometer RW204, draw the back and form feedback circuit with the negative pole input port that resistance R 249 is connected in series to the first operational amplifier N241; Second amplifying circuit 12 comprises the second operational amplifier N242 and second feedback circuit, described second feedback circuit comprises potentiometer RW205 and resistance R 252,6 pin of the second operational amplifier N242 meet potentiometer RW205, draw the back and form feedback circuit with negative pole input port 2 pin that resistance R 252 is connected in series to the second operational amplifier N242.
The first filtering amplitude limiter circuit 21 comprises limiter tube V246, V250 and capacitor C 243, C247, the negative electrode of the anode of limiter tube V246 and limiter tube V250 is connected to the 3 end input ports of sample circuit 3 and operational amplifier N241, the anode of the negative electrode of limiter tube V246 and limiter tube V250 is connected ground, and the 3 end input port voltages of the first operational amplifier N241 are carried out amplitude limit. and capacitor C 243 and C247 are connected on the 3 end input ports of the first operational amplifier N241 and voltage is waited to amplify in ground with the filtering first operational amplifier N241 input end noise; The second filtering amplitude limiter circuit 22 comprises limiter tube V251, V252 and capacitor C 244, C248, the negative electrode of the anode of limiter tube V251 and limiter tube V252 is connected to the 3 end input ports of the sample circuit 3 and the second operational amplifier N242, the anode of the negative electrode of limiter tube V251 and limiter tube V252 is connected ground, 3 end input port voltages to the second operational amplifier N242 carry out amplitude limit, and capacitor C 244 and C248 are connected on the 3 end input ports of the second operational amplifier N242 and voltage is waited to amplify in ground with the filtering second operational amplifier N242 input end noise.
The realization of enlargement factor of the present invention is to regulate by each feedback resistance in the feedback circuit to realize that trimmer potentiometer RW204 and potentiometer RW205 can get required enlargement factor in the circuit.
Claims (5)
1. little current detecting multiplying arrangement, comprise sample circuit (3), the MCU control circuit (4) of control sampled voltage size, and the amplifying circuit that the sampled voltage of sample circuit output is amplified, it is characterized in that: also be connected with the filtering amplitude limiter circuit between sample circuit and the amplifying circuit, described amplifying circuit comprises first amplifying circuit (11) and second amplifying circuit (12), the filtering amplitude limiter circuit comprises the first filtering amplitude limiter circuit (21) and the second filtering amplitude limiter circuit (22), the first via sampled voltage of MCU control circuit (4) control sample circuit (3) output through first filtering amplitude limiter circuit (21) limit filtration after input first amplifying circuit (11) amplify; The second road sampled voltage of MCU control circuit (4) control sample circuit (3) output through second filtering amplitude limiter circuit (22) limit filtration after input second amplifying circuit (12) amplify.
2. little current detecting multiplying arrangement as claimed in claim 1, it is characterized in that: described sample circuit (3) comprises sampling resistor, triode and relay, sampling resistor R124 and R126 series connection, sampling resistor R126 two ends relay K 303 in parallel, the base stage control end SWICH mouth of triode V230 is connected to MCU control circuit (4), and MCU control circuit (4) is realized relay K 303 is disconnected and closed control by the control to the SWICH mouth; First via sampled voltage is the R124 terminal voltage when relay K 303 closures, and when relay K 303 disconnected, the second road sampled voltage was R124, voltage sum on R126 two resistance.
3. little current detecting multiplying arrangement as claimed in claim 2, it is characterized in that: described first amplifying circuit (11) comprises the first operational amplifier N241 and first feedback circuit, described first feedback circuit comprises potentiometer RW204 and resistance R 249,6 pin of the first operational amplifier N241 meet potentiometer RW204, draw the back and form feedback circuit with the negative pole input port that resistance R 249 is connected in series to the first operational amplifier N241; Second amplifying circuit (12) comprises the second operational amplifier N242 and second feedback circuit, described second feedback circuit comprises potentiometer RW205 and resistance R 252,6 pin of the second operational amplifier N242 meet potentiometer RW205, draw the back and form feedback circuit with negative pole input port 2 pin that resistance R 252 is connected in series to the second operational amplifier N242.
4. little current detecting multiplying arrangement as claimed in claim 3, it is characterized in that: the first filtering amplitude limiter circuit (21) comprises limiter tube V246, V250 and capacitor C 243, C247, the negative electrode of the anode of limiter tube V246 and limiter tube V250 is connected to the 3 end input ports of sample circuit (3) and operational amplifier N241, the anode of the negative electrode of limiter tube V246 and limiter tube V250 is connected ground, and the 3 end input port voltages of the first operational amplifier N241 are carried out amplitude limit. and capacitor C 243 and C247 are connected on the 3 end input ports of the first operational amplifier N241 and voltage is waited to amplify in ground with the filtering first operational amplifier N241 input end noise; The second filtering amplitude limiter circuit (22) comprises limiter tube V251, V252 and capacitor C 244, C248, the negative electrode of the anode of limiter tube V251 and limiter tube V252 is connected to the 3 end input ports of the sample circuit (3) and the second operational amplifier N242, the anode of the negative electrode of limiter tube V251 and limiter tube V252 is connected ground, 3 end input port voltages to the second operational amplifier N242 carry out amplitude limit, and capacitor C 244 and C248 are connected on the 3 end input ports of the second operational amplifier N242 and voltage is waited to amplify in ground with the filtering second operational amplifier N242 input end noise.
5. as claim 3 or 4 described little current detecting multiplying arrangements, it is characterized in that: the described second operational amplifier N242 adopts the chopper-zero-stabilized type amplifier TLC2652CP of low maladjustment voltage drift; The described first operational amplifier N241 adopts the non-chopper-zero-stabilized type amplifier OP-07 of low maladjustment voltage drift.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206351013U CN201955374U (en) | 2010-12-01 | 2010-12-01 | Micro current detection and amplification device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206351013U CN201955374U (en) | 2010-12-01 | 2010-12-01 | Micro current detection and amplification device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201955374U true CN201955374U (en) | 2011-08-31 |
Family
ID=44499482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010206351013U Expired - Lifetime CN201955374U (en) | 2010-12-01 | 2010-12-01 | Micro current detection and amplification device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201955374U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102098012A (en) * | 2010-12-01 | 2011-06-15 | 海信科龙电器股份有限公司 | Detection and amplification device for micro current |
| CN107167649A (en) * | 2017-05-23 | 2017-09-15 | 杭州兆华电子有限公司 | A kind of electret microphone current testing circuit and its method of testing |
-
2010
- 2010-12-01 CN CN2010206351013U patent/CN201955374U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102098012A (en) * | 2010-12-01 | 2011-06-15 | 海信科龙电器股份有限公司 | Detection and amplification device for micro current |
| CN102098012B (en) * | 2010-12-01 | 2013-06-26 | 海信科龙电器股份有限公司 | Detection and amplification device for micro current |
| CN107167649A (en) * | 2017-05-23 | 2017-09-15 | 杭州兆华电子有限公司 | A kind of electret microphone current testing circuit and its method of testing |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102098012B (en) | Detection and amplification device for micro current | |
| CN204836096U (en) | Piezoelectric acceleration sensor's charge amplifier | |
| CN204188702U (en) | A kind of current detection circuit | |
| CN102288234A (en) | Electromagnetic flow meter | |
| CN201955374U (en) | Micro current detection and amplification device | |
| CN103151993A (en) | Precision alternating current amplifier | |
| CN203422416U (en) | High-end current detection circuit | |
| CN203193573U (en) | Precise alternating current amplifier | |
| CN206339589U (en) | Current detection circuit | |
| CN102751975B (en) | PWM and AI multiplexing port and controller | |
| CN106301068B (en) | A kind of digital driving power | |
| CN213544659U (en) | Non-isolated direct current bus voltage detection circuit | |
| CN204241556U (en) | A kind of 220VAC load current detection circuit | |
| CN202794285U (en) | Isolation processing circuit for small analog alternating current (AC) or direct current (DC) signals | |
| CN202614719U (en) | Amplifying circuit for carbon monoxide sensor | |
| CN204131469U (en) | For calibrating the accurate alternating voltage amplifier of lightning arrester block property current tester | |
| CN205377830U (en) | Analog output circuit | |
| CN205157638U (en) | Current acquisition circuit | |
| CN103869863B (en) | Sensor conditioning circuit | |
| CN104374995A (en) | 220 VAC load current detecting circuit | |
| CN204101618U (en) | A kind of Acquisition Circuit of high-frequency dust removing electric power outputting current | |
| CN203433402U (en) | Pulse digital amplifier circuit | |
| CN201608649U (en) | Pulse width modulation signal conversion voltage circuit | |
| CN208421050U (en) | A kind of unidirectional current sample circuit | |
| CN202583057U (en) | Probe signal processing circuit for infrared gas sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20110831 Effective date of abandoning: 20130626 |
|
| RGAV | Abandon patent right to avoid regrant |