CN1029646C - Zero blanking float method and device for micro current measurer - Google Patents
Zero blanking float method and device for micro current measurer Download PDFInfo
- Publication number
- CN1029646C CN1029646C CN 93105379 CN93105379A CN1029646C CN 1029646 C CN1029646 C CN 1029646C CN 93105379 CN93105379 CN 93105379 CN 93105379 A CN93105379 A CN 93105379A CN 1029646 C CN1029646 C CN 1029646C
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- China
- Prior art keywords
- chip microcomputer
- operational amplifier
- circuit
- microcomputer
- mean value
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- Expired - Fee Related
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- 238000006124 Pilkington process Methods 0.000 title claims abstract description 6
- 238000000034 method Methods 0.000 claims abstract description 7
- 230000015654 memory Effects 0.000 claims abstract description 5
- 238000005070 sampling Methods 0.000 claims description 7
- 238000001914 filtration Methods 0.000 claims description 3
- 238000005259 measurement Methods 0.000 abstract description 9
- 230000002349 favourable effect Effects 0.000 abstract 1
- 238000000691 measurement method Methods 0.000 abstract 1
- 239000003990 capacitor Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
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- Measurement Of Current Or Voltage (AREA)
- Indication And Recording Devices For Special Purposes And Tariff Metering Devices (AREA)
Abstract
The present invention relates to a zero blanking float method for a micro current measurer. Before the measurement, a microcomputer repeatedly samples for n times on instrument zero drift values, and an average value is stored in an internal memory. The microcomputer samples for n times on measured signals during the measurement to obtain an average value, then, the average value of the zero drift values is subtracted from the average value of the measured signals, and the result is displayed after the data processing. A measurer for the method comprises an operational amplifier, a zeroing circuit of the operational amplifier, a feedback circuit of the operational amplifier, a filter circuit, an A/D converter, the microcomputer and a display part. The measurer is characterized in that a linkage switch, a status circuit of the linkage switch and a microcomputer input port are arranged between an operational amplifier input end and the microcomputer. The present invention has convenient measurement method, needs no checking zero point, is favorable for automatization, and improves the measurement accuracy.
Description
The present invention relates to electronic measuring instrument and eliminate the method for zero point drift, and apparatus, particularly zero blanking float method and device thereof in Photoelectric Detection instrument and little current detecting instrument.
In the instrument of existing detection weak signal, there is the zero point drift problem of operational amplifier in great majority, mainly owing to reasons such as temperature, humidity produce.This instrument generally is by operational amplifier, and zeroing circuit, feedback circuit, and filtering circuit, the A/D transducer, and single-chip microcomputer, display unit is formed.But along with the time of measuring, the difference of environment, can change the zero point that originally regulated, and promptly produced zero point drift, influences measuring accuracy, all will be adjusted repeatedly zero point when measuring at every turn, and this automatic measurement to instrument has brought difficulty and trouble.
The purpose of this invention is to provide and a kind ofly eliminate the method that electronic measuring instrument zero point drift influences measuring accuracy, and the surveying instrument of this method of use is provided.
Design of the present invention is such: the method for eliminating zero point drift: instrument is before measurement, repeatedly its drift value is carried out n sampling, the mean value of getting its n time drift value leaves in the internal memory of single-chip microcomputer, is used for upgrading the former mean value that leaves n drift value in the single-chip microcomputer internal memory in; Instrument carries out n sampling to measured signal when measuring, get its mean value; And then from the mean value of measuring-signal, deduct the mean value of surveying instrument drift value, obtain actual measurement signal value; This value is carried out numeral by display unit and is shown after data processing.For the feature of using the custom-designed electronic measuring instrument of zero blanking float method is: between the input end and single-chip microcomputer of operational amplifier, be provided with a coupled switch, and on off state circuit, the single-chip microcomputer input port, a switch of coupled switch is connected the input end of operational amplifier, makes them be in normally open, and another switch of coupled switch is in normally off, be connected with the on off state circuit, the on off state circuit is connected with single-chip microcomputer by the single-chip microcomputer input port.
The present invention has following advantage: when feeble signal is measured, do not need to proofread the zero point of surveying instrument, this makes electronic measuring instrument carry out automatic measurement and has created advantage.In the measured value that display unit shows, do not comprise the zero point drift value of surveying instrument, so improved the measuring accuracy of instrument.Measuring method is easy simultaneously.
The invention will be further described below in conjunction with accompanying drawing.
Fig. 1 is an electrical schematic diagram of the present invention.
With reference to Fig. 1, that operational amplifier adopts is OP05 or OP07.Zeroing circuit is a resistance R
1, R
2, R
3, adjustable resistance W
1The electric current zeroing circuit that constitutes and by adjustable resistance W
2The voltage zeroing circuit that constitutes is formed.Feedback circuit is by resistance R
f, capacitor C
fForm.Filtering circuit is by resistance R
4, capacitor C
1Form.The A/D converter using be AD574, what single-chip microcomputer adopted is 8031, that display unit adopts is LED.Coupled switch K
1, K
2, K switch
1Make between two input ends of operational amplifier OP05 and be in normally open, K switch
2With by resistance R
5, capacitor C
2The status circuit of forming is connected.Status circuit communicates with single-chip microcomputer 8031 by single-chip microcomputer input port 74LS244.Y
0It is the chip select control signal of 8031 pairs of single-chip microcomputer input ports of single-chip microcomputer 74LS244.Measuring instrument is not when measuring, because coupled switch K
1Often open, measuring-signal does not insert the input end of operational amplifier OP05, and the value of its output terminal is the drift value of operational amplifier OP05, the digital quantity input single-chip microcomputer 8031 after A/D transducer AD574 conversion.Because K switch
2Normally closed, the state of switch is delivered to single-chip microcomputer by on off state circuit and single-chip microcomputer input port, makes the 1st D of single-chip data line
0Equal zero,, get its mean value and be stored in single-chip microcomputer 8031 internal memories so single-chip microcomputer 8031 is sampled 256 times to the drift value of operational amplifier OP05 repeatedly always.When measuring instrument is being measured, press coupled switch K
1, K
2, K switch
1Connect the measured signal source, what this moment, operational amplifier OP05 exported is actual measured value and its drift value sum.Digital quantity input single-chip microcomputer 8031 after A/D transducer AD574 conversion.Owing to K switch this moment
2Open, on off state makes the 1st D of single-chip data line by on off state circuit and single-chip microcomputer input port
0Equal 1, so 8031 pairs of measured signal samplings of single-chip microcomputer have comprised actual measurement signal value and drift and have been worth two parts in the sampled value, this moment, same sampling was 256 times, got its mean value again.The mean value of the sampled value during measurement deducts the mean value of drift value, obtains actual measured value.After data processing, carry out numeral by display unit and show again.Owing to adopted zero suppression to float value and sampling multicycle mean value, improved the measuring accuracy of measuring instrument.
Claims (2)
1, a kind of zero blanking float method of micro current instrument is characterized in that: before 1. measuring, the single-chip microcomputer of surveying instrument carries out n sampling to its drift value repeatedly, gets its mean value and upgrades the mean value that leaves former n the drift value in its internal memory in; When 2. measuring, the single-chip microcomputer of surveying instrument carries out n sampling to measured signal, gets its mean value; 3. from measuring-signal mean value, deduct the mean value of surveying instrument drift value; 4. its result carries out the numeral demonstration by display unit after data processing.
2, a kind of based on the described method of claim 1 and custom-designed surveying instrument, comprise operational amplifier, and zeroing circuit, feedback circuit, filtering circuit, A/D transducer, single-chip microcomputer, display unit, it is characterized in that between the input end and single-chip microcomputer of operational amplifier, be provided with a coupled switch, on off state circuit and single-chip microcomputer input port, a switch of coupled switch is connected the input end of operational amplifier, another switch is connected with the on off state circuit, and the on off state circuit is connected with single-chip microcomputer by the single-chip microcomputer input port.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93105379 CN1029646C (en) | 1993-05-08 | 1993-05-08 | Zero blanking float method and device for micro current measurer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 93105379 CN1029646C (en) | 1993-05-08 | 1993-05-08 | Zero blanking float method and device for micro current measurer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1080726A CN1080726A (en) | 1994-01-12 |
| CN1029646C true CN1029646C (en) | 1995-08-30 |
Family
ID=4985690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 93105379 Expired - Fee Related CN1029646C (en) | 1993-05-08 | 1993-05-08 | Zero blanking float method and device for micro current measurer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1029646C (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103245846B (en) * | 2012-02-10 | 2015-03-11 | 南京弘毅电气自动化有限公司 | Dynamic zero drift filtering algorithm for relay protection |
| CN102857205B (en) * | 2012-08-30 | 2016-06-01 | 北京经纬恒润科技有限公司 | Signal conditioning device, sensor and signal acquiring processing system |
| CN105629042A (en) * | 2014-10-27 | 2016-06-01 | 北京航天计量测试技术研究所 | Current intelligent measurement module |
| CN104678154B (en) * | 2015-03-13 | 2017-10-20 | 南京大全自动化科技有限公司 | A kind of method that regulation power distribution equipment zero based on adaptive nulling technology floats |
| CN106100100B (en) * | 2016-08-28 | 2018-05-08 | 东文高压电源（天津）股份有限公司 | One kind is based on CIGS thin film component charging control circuit and control method |
| CN109596512B (en) * | 2019-01-10 | 2021-06-08 | 珠海多创科技有限公司 | Method for measuring direct current micro current in object |
| CN113238178A (en) * | 2021-05-14 | 2021-08-10 | 武汉理工大学 | Zero drift signal elimination method of alternating current signal sensor |
-
1993
- 1993-05-08 CN CN 93105379 patent/CN1029646C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1080726A (en) | 1994-01-12 |
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