CN203117295U - Resistance value detection circuit and device - Google Patents
Resistance value detection circuit and device Download PDFInfo
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- CN203117295U CN203117295U CN 201320039897 CN201320039897U CN203117295U CN 203117295 U CN203117295 U CN 203117295U CN 201320039897 CN201320039897 CN 201320039897 CN 201320039897 U CN201320039897 U CN 201320039897U CN 203117295 U CN203117295 U CN 203117295U
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- operational amplifier
- resistance value
- testing
- constant voltage
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Abstract
The utility model belongs to the circuit detection field and provides a resistance value detection circuit which is used for detecting whether the resistance value of a resistor R1 to be detected has changed or not. The resistance value detection circuit comprises a divider resistor R2; a constant-voltage module having an output end output a constant voltage; and an operational amplifier. The positive input end of the operational amplifier is connected with the output end of the constant-voltage module. The inverting input end of the operational amplifier serves as a first testing end and is grounded through the divider resistor R2. The output end of the operational amplifier serves as a second testing end. The resistor R1 to be detected is connected between the first testing end and the second testing end. A constant current source circuit is formed by combining the operational amplifier and the divider resistor R2. The currents of the resistor R1 to be detected and the divider resistor R2 are equal to each other and constant. Therefore, when the output voltage of the operational amplifier is detected to be changed, then the resistance value of the resistor R1 to be detected is indicated to be also changed. In this way, the problem that resistance value measurement in common occasions cannot reach a precision grade is well solved.
Description
Technical field
The utility model belongs to the electric circuit inspection field, relates in particular to a kind of resistance value observation circuit and device.
Background technology
At present, in a lot of control products, sometimes need that resistance is invariable in the product, can not vary with temperature and change, except the resistance that adopts micron order, also need resistance value is monitored in real time, and in general application scenario, lack under the accurate measuring equipment situation, can not reach micron order to the measurement of resistance value, this moment, the slight change of resistance value can not be made good indication.
The utility model content
The purpose of the utility model embodiment is to provide a kind of simple and reliable resistance value observation circuit, is intended to solve general occasion can not reach micron order to the measurement of resistance value problem.
The utility model embodiment is achieved in that a kind of resistance value testing circuit, and whether the resistance that is used for test testing resistance R1 changes, and comprising:
Divider resistance R2;
The constant voltage module, its output terminal output constant voltage;
Operational amplifier, its normal phase input end is connected with the output terminal of described constant voltage module, the inverting input of described operational amplifier is as first test lead and through described divider resistance R2 ground connection, the output terminal of described operational amplifier is as second test lead, described testing resistance R1 is connected between described first test lead and second test lead, and the voltage that the output terminal of described operational amplifier is exported changes along with the change in resistance of described testing resistance R1.
Further, described constant voltage module is high-precision reference voltage source.
Further, described constant voltage module is that model is the reference voltage source of AD581.
Further, the model of described operational amplifier is OP07, OP37,0P211 or LM4562.
Another purpose of the utility model embodiment is to provide a kind of resistance value pick-up unit, comprises the resistance value testing circuit that whether changes for the resistance of testing testing resistance R1, and described resistance value testing circuit comprises:
Divider resistance R2;
The constant voltage module, its output terminal output constant voltage;
Operational amplifier, its normal phase input end is connected with the output terminal of described constant voltage module, the inverting input of described operational amplifier is as first test lead and through described divider resistance R2 ground connection, the output terminal of described operational amplifier is as second test lead, described testing resistance R1 is connected between described first test lead and second test lead, and the voltage that the output terminal of described operational amplifier is exported changes along with the change in resistance of described testing resistance R1.
Further, described constant voltage module is high-precision reference voltage source.
Further, described constant voltage module is that model is the reference voltage source of AD581.
Further, the model of described operational amplifier is OP07, OP37,0P211 or LM4562.
During above-mentioned resistance value testing circuit test resistance, according under the situation of current constant, if resistance value changes, the principle that also changes of the dividing potential drop of this resistance so, and utilize operational amplifier to form constant-current source circuit in conjunction with divider resistance R2, the electric current that forms testing resistance R1 and divider resistance R2 equates also constant, so if detect to such an extent that the output voltage of operational amplifier occur to change, variation has also taken place in the resistance that then can indicate testing resistance R1, the testing circuit that utilizes simple components and parts to be combined into has solved general occasion can not reach micron order to the measurement of resistance value problem.
Description of drawings
Fig. 1 is the circuit diagram of the resistance value observation circuit that provides of the utility model embodiment.
Embodiment
In order to make the technical problems to be solved in the utility model, technical scheme and beneficial effect clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein only in order to explaining the utility model, and be not used in restriction the utility model.
As shown in Figure 1, a kind of resistance value testing circuit, whether its resistance that is used for test testing resistance R1 changes, and comprises divider resistance R2, constant voltage module 110 and operational amplifier 120.
The output terminal output constant voltage Vout of constant voltage module 110; The normal phase input end 1 of operational amplifier 120 is connected with the output terminal of constant voltage module 110, the inverting input 2 of operational amplifier 120 is as first test lead 130 and through divider resistance R2 ground connection, the output terminal 3 of operational amplifier 120 is as second test lead 140, testing resistance R1 is connected between first test lead 130 and second test lead 140, and the voltage that the output terminal 3 of operational amplifier 120 is exported changes along with the change in resistance of testing resistance R1.
During above-mentioned resistance value testing circuit test resistance, first test lead 130 and second test lead 140 are connected the two ends of testing resistance R1.According under the situation of current constant, if resistance value changes, the principle that also changes of the dividing potential drop of this resistance so, and utilize operational amplifier 120 to form constant-current source circuit in conjunction with divider resistance R2, the electric current that forms testing resistance R1 and divider resistance R2 equates also constant, so if detect to such an extent that the output voltage of operational amplifier 120 occur to change, variation has also taken place in the resistance that then can indicate testing resistance R1, the testing circuit that utilizes simple components and parts to be combined into has solved general occasion can not reach micron order to the measurement of resistance value problem.
In a preferred embodiment, constant voltage module 110 is high-precision reference voltage source, and in the present embodiment, constant voltage module 110 is the reference voltage source of AD581 for model.Yet in other embodiments, constant voltage module 110 can be that model is 7805 three-terminal voltage-stabilizing integrated chip.
In the present embodiment, the model that operational amplifier 120 is is OP07, at this moment, and the dual power supply of operational amplifier 120 positive-negative power input ends (4 shown in Fig. 1 and 5) access ± 12V.In other embodiments, the supply voltage scope that operational amplifier 120 positive-negative power input ends (4 and 5) insert: ± 3V～± 22V, also can use single supply to insert positive supply input end 4, negative supply input end 5 ground connection.
In other preferred embodiment, operational amplifier 120 can also be that model is the operational amplifier 120 of 0P211, LM4562, uA741, uA709, LM301, LM308, LF356, op37 or max427.
Form negative-feedback circuit by operational amplifier 120, the normal phase input end of operational amplifier 120 is connected with the output terminal of constant voltage module 110, according to operational amplifier 120 " empty short " principle, the normal phase input end 1 of operational amplifier 120 and the voltage of inverting input 2 are Vout.
Do not suck electric current because the normal phase input end 1 input impedance height of operational amplifier 120, normal phase input end 1 can be thought, therefore the size of current that flows through from testing resistance R1 and divider resistance R2 is fixed.So, form the constant-current source circuit that operational amplifier 120 and divider resistance R2 form, the electric current of supposing this constant-current source circuit is Ir, and the output terminal 3 that necessarily equals operational amplifier 120 of the electric current by divider resistance R2 flows through the electric current of testing resistance R1, therefore the voltage V that leads to the output terminal 3 of test operational amplifier 120, can calculate the resistance of testing resistance R1, computing formula is: r1=V/Ir, r1 are the resistance of testing resistance R1.Because the constant current value that Ir provides for constant-current source circuit, thus only need by test operational amplifier 120 output voltage V just as can be known testing resistance R1 no change is arranged.The resistance value testing circuit is simple and reliable, can arbitrarily assemble use in general use occasion.
In addition, also provide a kind of resistance value pick-up unit, it comprises above-mentioned resistance value testing circuit, and the circuit structure of resistance value testing circuit and the principle of work and power thereof repeat no more as mentioned above here.
The above only is preferred embodiment of the present utility model; not in order to limit the utility model; all any modifications of within spirit of the present utility model and principle, doing, be equal to and replace and improvement etc., all should be included within the protection domain of the present utility model.
Claims (8)
1. whether a resistance value testing circuit changes for the resistance of testing testing resistance R1, it is characterized in that, comprising:
Divider resistance R2;
The constant voltage module, its output terminal output constant voltage;
Operational amplifier, its normal phase input end is connected with the output terminal of described constant voltage module, the inverting input of described operational amplifier is as first test lead and through described divider resistance R2 ground connection, the output terminal of described operational amplifier is as second test lead, described testing resistance R1 is connected between described first test lead and second test lead, and the voltage that the output terminal of described operational amplifier is exported changes along with the change in resistance of described testing resistance R1.
2. resistance value testing circuit as claimed in claim 1 is characterized in that, described constant voltage module is high-precision reference voltage source.
3. resistance value testing circuit as claimed in claim 1 or 2 is characterized in that, described constant voltage module is that model is the reference voltage source of AD581.
4. resistance value testing circuit as claimed in claim 1 is characterized in that, the model of described operational amplifier is OP07, OP37,0P211 or LM4562.
5. a resistance value pick-up unit is characterized in that, comprises the resistance value testing circuit that whether changes for the resistance of testing testing resistance R1, and described resistance value testing circuit comprises:
Divider resistance R2;
The constant voltage module, its output terminal output constant voltage;
Operational amplifier, its normal phase input end is connected with the output terminal of described constant voltage module, the inverting input of described operational amplifier is as first test lead and through described divider resistance R2 ground connection, the output terminal of described operational amplifier is as second test lead, described testing resistance R1 is connected between described first test lead and second test lead, and the voltage that the output terminal of described operational amplifier is exported changes along with the change in resistance of described testing resistance R1.
6. resistance value pick-up unit as claimed in claim 5 is characterized in that, described constant voltage module is high-precision reference voltage source.
7. as claim 5 or 6 described resistance value pick-up units, it is characterized in that described constant voltage module is that model is the reference voltage source of AD581.
8. resistance value pick-up unit as claimed in claim 5 is characterized in that, the model of described operational amplifier is OP07, OP37,0P211 or LM4562.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320039897 CN203117295U (en) | 2013-01-24 | 2013-01-24 | Resistance value detection circuit and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320039897 CN203117295U (en) | 2013-01-24 | 2013-01-24 | Resistance value detection circuit and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203117295U true CN203117295U (en) | 2013-08-07 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320039897 Expired - Fee Related CN203117295U (en) | 2013-01-24 | 2013-01-24 | Resistance value detection circuit and device |
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| CN (1) | CN203117295U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109708827A (en) * | 2018-12-18 | 2019-05-03 | 瑞纳智能设备股份有限公司 | Circuit and method with pipeline node leakage flow hierarchical detection |
| CN110954730A (en) * | 2019-12-26 | 2020-04-03 | 崔建国 | Linear scale ohmmeter based on constant current source and manufacturing method |
| CN111190054A (en) * | 2020-03-18 | 2020-05-22 | 成都优蕊光电科技有限公司 | Ultrahigh resistance value measuring circuit and device for alternating current characteristic detection |
| CN113702711A (en) * | 2020-05-21 | 2021-11-26 | 圣邦微电子（北京）股份有限公司 | Resistance test circuit and resistance test method |
| CN113702710A (en) * | 2020-05-21 | 2021-11-26 | 圣邦微电子（北京）股份有限公司 | Resistance test circuit and resistance test method |
-
2013
- 2013-01-24 CN CN 201320039897 patent/CN203117295U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109708827A (en) * | 2018-12-18 | 2019-05-03 | 瑞纳智能设备股份有限公司 | Circuit and method with pipeline node leakage flow hierarchical detection |
| CN110954730A (en) * | 2019-12-26 | 2020-04-03 | 崔建国 | Linear scale ohmmeter based on constant current source and manufacturing method |
| CN111190054A (en) * | 2020-03-18 | 2020-05-22 | 成都优蕊光电科技有限公司 | Ultrahigh resistance value measuring circuit and device for alternating current characteristic detection |
| CN113702711A (en) * | 2020-05-21 | 2021-11-26 | 圣邦微电子（北京）股份有限公司 | Resistance test circuit and resistance test method |
| CN113702710A (en) * | 2020-05-21 | 2021-11-26 | 圣邦微电子（北京）股份有限公司 | Resistance test circuit and resistance test method |
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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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130807 Termination date: 20190124 |