CN202748160U - Anti-interference temperature sampling circuit - Google Patents
Anti-interference temperature sampling circuit Download PDFInfo
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- CN202748160U CN202748160U CN 201220423907 CN201220423907U CN202748160U CN 202748160 U CN202748160 U CN 202748160U CN 201220423907 CN201220423907 CN 201220423907 CN 201220423907 U CN201220423907 U CN 201220423907U CN 202748160 U CN202748160 U CN 202748160U
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Abstract
An anti-interference temperature sampling circuit belongs to the measuring technology field. The anti-interference temperature sampling circuit comprises a temperature sampling resistor, a signal converting circuit and a differential amplification circuit, an input end of the signal converting circuit is connected with the temperature sampling resistor, the differential amplification circuit comprises an operational amplifier, a first capacitor and six resistors, an inverted input end of the operational amplifier is connected with one differential output end of the signal converting circuit after passing through a first resistor and a second resistor successively, a non-inverting input end is connected with the other differential output end of the signal converting circuit after passing through a third resistor and a fourth resistor successively, a serial-connection point of the first resistor and the second resistor is connected with an output end of the operational amplifier through a fifth resistor, a serial-connection point of the third resistor and the fourth resistor is connected with the ground through a sixth resistor; and the first capacitor is connected between two input ends of the operational amplifier. The circuit has a good inhibition effect on strong radio frequency interference signals, is simple in structure and low in costs, and is suitable for various application occasions.
Description
Technical field
The utility model relates to a kind of temperature sampling circuit that can work under very strong Radio frequency interference (RFI), belong to field of measuring technique.
Background technology
At present, many temperature sampling circuits all consist of take temperature sampling resistance and operational amplifier as main devices, because design is unreasonable, when having very strong Radio Frequency Interfere, Radio Frequency Interfere can be brought the DC maladjustment error to output signal by the input stage rectification of operational amplifier, and this error is difficult to eliminate with the low-pass filter of temperature sampling circuit output terminal, if Radio frequency interference (RFI) is intermittence, will cause temperature sampling circuit to lose efficacy.
Adopt instrument amplifier to add the interference that the RFI wave filter can the strong radiofrequency signal of establishment, improve the reliability of temperature sampling circuit, but can significantly improve like this cost of temperature sampling circuit, be unsuitable for conventional application scenario.Therefore be necessary to design a kind of simple in structure, with low cost and temperature sampling circuit that antijamming capability is strong.
The utility model content
The purpose of this utility model is to overcome the deficiencies in the prior art, a kind of anti-interference temperature sampling circuit simple in structure, with low cost is provided.
Problem described in the utility model is realized by following technical scheme:
A kind of anti-interference temperature sampling circuit, it comprises temperature sampling resistance, signaling conversion circuit and differential amplifier circuit, the input end jointing temp sampling resistor of described signaling conversion circuit; Described differential amplifier circuit comprises operational amplifier, the first electric capacity and six resistance, the inverting input of described operational amplifier connects a difference output end of signaling conversion circuit successively through the first resistance and the second resistance, its in-phase input end connects another difference output end of signaling conversion circuit successively through the 3rd resistance and the 4th resistance, the serial connection of the first resistance and the second resistance o'clock connects the output terminal of operational amplifier through the 5th resistance, the serial connection of the 3rd resistance and the 4th resistance is o'clock through the 6th resistance eutral grounding; The first electric capacity is connected between two input ends of operational amplifier.
Above-mentioned anti-interference temperature sampling circuit, described signaling conversion circuit comprises three end common mode chokes, three resistance and three electric capacity, the positive pole of the input end jointing temp sampling resistor of the first coil of three end common mode chokes, output termination reference voltage, the negative pole of the input end jointing temp sampling resistor of the second coil of three end common mode chokes and tertiary coil, the output terminal of tertiary coil is through the 7th resistance eutral grounding, a termination reference voltage after the 8th resistance and the 9th resistance are connected in series, one end ground connection, the serial connection point of the 8th resistance and the 9th resistance with are connected the output terminal of the second coil of end common mode choke and are connected the second electric capacity with differential amplifier circuit two input ends respectively as two output terminals of differential signal, the 3rd electric capacity and the 4th electric capacity are respectively the filter capacitors of three coil input ends of three end common mode chokes.
Above-mentioned anti-interference temperature sampling circuit, between signaling conversion circuit and differential amplifier circuit, also be provided with filtering circuit, described filtering circuit comprises two resistance and three electric capacity, a termination the 8th resistance of the tenth resistance and being connected in series a little of the 9th resistance, another termination second resistance; The output terminal of the second coil of one termination, the three end common mode chokes of the 11 resistance, another termination the 4th resistance; One termination the tenth resistance of the 5th electric capacity and the tie point of the second resistance, other end ground connection; One termination the 11 resistance of the 6th electric capacity and the tie point of the 4th resistance, other end ground connection; One termination the tenth resistance of the 7th electric capacity and the tie point of the second resistance, the tie point of another termination the 11 resistance and the 4th resistance.
The utility model utilizes signaling conversion circuit to convert the temperature signal of temperature sampling resistance output to differential signal, and this signal is delivered to A/D convertor circuit through filtering circuit filtering, differential amplifier circuit after amplifying.Because the first electric capacity in three end common mode chokes, filtering circuit and the differential amplifier circuit all has good filter action, thereby this circuit has very high common-mode rejection ratio, greatly improve the antijamming capability of temperature sampling circuit, reduced simultaneously the sampling bandwidth.
The utility model not only has good inhibiting effect to strong Radio Frequency Interfere, and simple in structure, and is with low cost, is applicable to various application scenarios.
Description of drawings
The utility model is described in further detail below in conjunction with accompanying drawing.
Fig. 1 is electrical schematic diagram of the present utility model.
Each label is among the figure: RT, temperature sampling resistance; L, three end common mode chokes; F, operational amplifier; C1～C7, electric capacity; R1～R11, the first resistance ~ the 11 resistance.
Embodiment
Referring to Fig. 1, the utility model is comprised of three end common mode choke L, temperature sampling resistance R T, operational amplifier F, 11 resistance and 7 electric capacity; Wherein temperature sampling resistance R T adopts three end PT100, three output terminals of PT100 meet respectively (the first coil L1 of three coils of three end common mode choke L, the second coil L2, tertiary coil L3) input end, the output termination reference voltage (VREF) of the first coil L1, the output terminal of tertiary coil L3 is through the 7th resistance R 7 ground connection, reference voltage V REF is through the 8th resistance R 8 and the 9th resistance R 9 dividing potential drops, the serial connection point of the 8th resistance R 8 and the 9th resistance R 9 is a differential signal output terminal IN+ of signaling conversion circuit, the 8th resistance R 8 wherein, the 9th resistance R 9, the 7th resistance R 7 and temperature sampling resistance R T consist of the sampling electric bridge, electric bridge is output as IN+, IN-, the tenth resistance R 10, the 11 resistance R 11 and the 5th capacitor C 5, the 6th capacitor C 6 and the 7th capacitor C 7 consist of the RC filtering circuit, the first resistance R 1, the 3rd resistance R 3, the 4th capacitor C 4 second resistance R 2, the 5th resistance R 5, the 4th resistance R 4, the 6th resistance R 6 and operational amplifier F have consisted of differential amplifier circuit, wherein the first resistance R 1, the 3rd resistance R 3 and the 4th capacitor C 4 are piths that this circuit is different from existing temperature sampling circuit.
The utility model adopts common operational amplifier to make the effect that has but obtained instrument amplifier.Through on-the-spot test, conventional temperature sample circuit output signal under strong Radio frequency interference (RFI) is a prescription ripple, and the utility model can work.
The utility model principle of work is as follows:
When temperature changes, the resistance of temperature sampling resistance R T changes, IN+, the IN-voltage-to-ground also changes, differential amplifier circuit is delivered in the A/D convertor circuit after this signal is amplified, when temperature sampling resistance R T is subject to very strong Radio frequency interference (RFI), its output signal is first through the first filtering of three end common mode choke L, again through entering in the differential amplifier circuit after the filtering of RC filtering circuit, the first resistance R 1 in the differential amplifier circuit, the 3rd resistance R 3, the 4th capacitor C 4 further improves the antijamming capability of amplifier, improve the amplifier common-mode rejection ratio, reduced simultaneously the sampling bandwidth.Temperature itself is a kind of signal of slow variation, and this circuit has good inhibiting effect to strong Radio frequency interference (RFI).
Claims (3)
1. an anti-interference temperature sampling circuit is characterized in that, it comprises temperature sampling resistance (RT), signaling conversion circuit and differential amplifier circuit, the input end jointing temp sampling resistor (RT) of described signaling conversion circuit; Described differential amplifier circuit comprises operational amplifier (F), the first electric capacity (C1) and six resistance, the inverting input of described operational amplifier (F) connects a difference output end of signaling conversion circuit successively through the first resistance (R1) and the second resistance (R2), its in-phase input end connects another difference output end of signaling conversion circuit successively through the 3rd resistance (R3) and the 4th resistance (R4), the serial connection of the first resistance (R1) and the second resistance (R2) o'clock connects the output terminal of operational amplifier (F) through the 5th resistance (R5), the serial connection of the 3rd resistance (R3) and the 4th resistance (R4) is o'clock through the 6th resistance (R6) ground connection; The first electric capacity (C1) is connected between two input ends of operational amplifier (F).
2. anti-interference temperature sampling circuit according to claim 1, it is characterized in that, described signaling conversion circuit comprises three end common mode chokes (L), three resistance and three electric capacity, the positive pole of the input end jointing temp sampling resistor (RT) of first coil (L1) of three end common mode chokes (L), output termination reference voltage, the negative pole of second coil (L2) of three end common mode chokes (L) and the input end jointing temp sampling resistor (RT) of tertiary coil (L3), the output terminal of tertiary coil (L3) is through the 7th resistance (R7) ground connection, a termination reference voltage after the 8th resistance (R8) is connected in series with the 9th resistance (R9), one end ground connection, the serial connection point of the 8th resistance (R8) and the 9th resistance (R9) with are connected the output terminal of the second coil (L2) of end common mode choke (L) and are connected respectively the second electric capacity (C2) with differential amplifier circuit two input ends as two output terminals of differential signal, the 3rd electric capacity (C3) and the 4th electric capacity (C4) are respectively the filter capacitors of three coil input ends of three end common mode chokes (L).
3. anti-interference temperature sampling circuit according to claim 2, it is characterized in that, between signaling conversion circuit and differential amplifier circuit, also be provided with filtering circuit, described filtering circuit comprises two resistance and three electric capacity, one termination the 8th resistance (R8) of the tenth resistance (R10) and being connected in series a little of the 9th resistance (R9), another termination second resistance (R2); The output terminal of second coil (L2) of one termination, the three end common mode chokes (L) of the 11 resistance (R11), another termination the 4th resistance (R4); One termination the tenth resistance (R10) of the 5th electric capacity (C5) and the tie point of the second resistance (R2), other end ground connection; One termination the 11 resistance (R11) of the 6th electric capacity (C6) and the tie point of the 4th resistance (R4), other end ground connection; One termination the tenth resistance (R10) of the 7th electric capacity (C7) and the tie point of the second resistance (R2), the tie point of another termination the 11 resistance (R11) and the 4th resistance (R4).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220423907 CN202748160U (en) | 2012-08-24 | 2012-08-24 | Anti-interference temperature sampling circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220423907 CN202748160U (en) | 2012-08-24 | 2012-08-24 | Anti-interference temperature sampling circuit |
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| Publication Number | Publication Date |
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| CN202748160U true CN202748160U (en) | 2013-02-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN 201220423907 Expired - Fee Related CN202748160U (en) | 2012-08-24 | 2012-08-24 | Anti-interference temperature sampling circuit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108955917A (en) * | 2018-08-15 | 2018-12-07 | 四川西南交大铁路发展股份有限公司 | A kind of rail temperature measuring device and system |
| CN108955933A (en) * | 2018-08-15 | 2018-12-07 | 四川西南交大铁路发展股份有限公司 | A kind of measuring circuit and parameter selection method improving rail temperature measurement accuracy |
| CN110988440A (en) * | 2019-12-19 | 2020-04-10 | 上海微阱电子科技有限公司 | Current monitoring device and method of CMOS device |
-
2012
- 2012-08-24 CN CN 201220423907 patent/CN202748160U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108955917A (en) * | 2018-08-15 | 2018-12-07 | 四川西南交大铁路发展股份有限公司 | A kind of rail temperature measuring device and system |
| CN108955933A (en) * | 2018-08-15 | 2018-12-07 | 四川西南交大铁路发展股份有限公司 | A kind of measuring circuit and parameter selection method improving rail temperature measurement accuracy |
| CN108955933B (en) * | 2018-08-15 | 2021-06-04 | 四川西南交大铁路发展股份有限公司 | Measuring circuit for improving temperature measurement precision of steel rail and parameter selection method |
| CN110988440A (en) * | 2019-12-19 | 2020-04-10 | 上海微阱电子科技有限公司 | Current monitoring device and method of CMOS device |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C41 | Transfer of patent application or patent right or utility model | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 050035 No. 56, 3 Kunlun street, Shijiazhuang Development Zone, Hebei, China Patentee after: Shijiazhuang Guoyao Eletronic Co.,Ltd. Patentee after: SHENZHEN GYE ELECTRONIC TECHNOLOGY Co.,Ltd. Address before: 050035 No. 56, 3 Kunlun street, Shijiazhuang Development Zone, Hebei, China Patentee before: Shijiazhuang Guoyao Eletronic Co.,Ltd. Patentee before: Shenzhen Guoyao Electronic Technology Co.,Ltd. |
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| TR01 | Transfer of patent right |
Effective date of registration: 20151216 Address after: Longgang District of Shenzhen City, Guangdong province 518129 Buji Bantian Jihua Road, Liuzhou Choi industrial city 10 Building 6 layer Patentee after: SHENZHEN GYE ELECTRONIC TECHNOLOGY Co.,Ltd. Address before: 050035 No. 56, 3 Kunlun street, Shijiazhuang Development Zone, Hebei, China Patentee before: Shijiazhuang Guoyao Eletronic Co.,Ltd. Patentee before: SHENZHEN GYE ELECTRONIC TECHNOLOGY Co.,Ltd. |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130220 Termination date: 20180824 |
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| CF01 | Termination of patent right due to non-payment of annual fee |