CN202256477U - Digital voltmeter adaptable for automatically switching range - Google Patents
Digital voltmeter adaptable for automatically switching range Download PDFInfo
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- CN202256477U CN202256477U CN2011200010556U CN201120001055U CN202256477U CN 202256477 U CN202256477 U CN 202256477U CN 2011200010556 U CN2011200010556 U CN 2011200010556U CN 201120001055 U CN201120001055 U CN 201120001055U CN 202256477 U CN202256477 U CN 202256477U
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Abstract
The utility model relates to a digital voltmeter adaptable for automatically switching range, and belongs to the technical field of electronic measurement. The voltmeter comprises an input circuit, a range switching circuit, an A/D converter, a master single chip, an LED (light emitting diode) display module and a power module, wherein the input circuit, the range switching circuit, the A/D converter, the master single chip, and the LED display module are connected in sequence; the input circuit, the range switching circuit, the A/D converter, the master single chip and the LED display module are connected with the power module, respectively. The voltmeter is capable of precisely measuring a direct-current voltage of 0-400V, and is capable of automatically switching the range with stable performance and sensitive response.
Description
Technical field
The utility model relates to the automatic converting digital voltage table of a kind of range, belongs to electronic measuring technology field.
Background technology
Voltage is a fundamental physical quantity, is one of three basic parameters (voltage, electric current, power) that characterize in the lumped circuit electrical signal energy, and voltage measurement is the substance in the electronic surveying.In electronic circuit, the duty of circuit such as resonance, balance, by the dynamic range of, saturated and working point all show with voltage form usually.The control signal of electronic equipment, feedback signal and other information mainly show as voltage.In the measurement of non electrical quantity, also utilize various kinds of sensors part device more, convert non-electrical quantity to voltage parameter.
Digital voltmeter is to adopt Digital Measuring Technique, converts continuous amount (input voltage) to discontinuous, discrete digitized forms and the instrument that shows.As a kind of surveying instrument of the most basic in the hyundai electronics measurement and core, also increasingly high to the precision and the functional requirement of its measurement.Because voltage measurement is the most general; Coverage is wide; Particularly differ under the great situation in micro voltage, high voltage and measured signal power; Should guarantee that the measuring accuracy of weak signal takes into account the measurement range of strong signal again, the voltage table of traditional manual switch range has certain degree of difficulty on measuring technique; Simultaneously, if measurement range selection is improper, not only can cause measuring accuracy to descend even the instrument damage.Voltage measurement is the basis of electronic surveying, in the measurement debugging of electronic circuit and equipment, requires test result to have measuring accuracy height, stable performance.The automatic converting digital voltage table of a kind of range shows that from test result this voltage table has the precision height, and the characteristics of stable performance are widely used in voltage measurement.
The utility model content
The utility model provides a kind of range automatic converting digital voltage table; Have 16 bit resolutions; Is core with single chip computer AT 89S52 as the master controller of measuring; LTC1865 is the basis with the A/D conversion chip, in conjunction with the range automatic switching circuit, can carry out the range accurate measurement of conversion automatically to the DC voltage of 0～400V.
The utility model adopts following technical scheme for solving its technical matters:
The automatic converting digital voltage table of a kind of range; Comprise input circuit, range change-over circuit, A/D converter, main control singlechip, LED display module and power module; Wherein, Input circuit, range change-over circuit, A/D converter, main control singlechip and LED display module link to each other in proper order, and input circuit, range change-over circuit, A/D converter, main control singlechip and LED display module all are connected with power module respectively.
The beneficial effect of the utility model is following:
1, it is fast to have a slewing rate, precision high (remaining in 0.025%), stable performance, circuit characteristic of simple.
2, range is changed and the high definition digital Presentation Function automatically.
3, voltage measurement wide ranges can accurately be measured the DC voltage of 0～400V.
4, have stronger expanded function, input end adds an absolute value converter, converts the alternating voltage amplitude into corresponding DC voltage value, realizes the measurement of of ac.
5, response is sensitive, shows stable.
Description of drawings:
Fig. 1 is the structured flowchart of the automatic converting digital voltage table of range.
Fig. 2 digital voltmeter electrical schematic diagram.
Fig. 3 range automatic switching circuit figure.
Fig. 4 main program flow chart.
Fig. 5 range converse routine process flow diagram.
Embodiment
Below in conjunction with accompanying drawing the invention is explained further details.
Digital voltmeter measuring DC voltage scope is 0～400V, and measuring accuracy≤0.025% can carry out range conversion (design is divided into 0～0.4V, 0.4～4V, 4V～40V, four ranges of 40V～400V) automatically.The structured flowchart of the automatic converting digital voltage table of range is as shown in Figure 1, and it mainly partly is made up of input circuit, range change-over circuit, A/D conversion, main control singlechip, LED demonstration and power module etc.Simulating signal to be measured is through input circuit processing, filtering interfering output direct current signal; The range change-over circuit is according to the size of prime direct current signal, and the signal voltage that selection decays or the amplifying signal processing mode is guaranteed to deliver to the A/D converter automatically is between 0.4～4V; The result that main control singlechip is changed according to A/D controls the automatic realization of range change-over circuit, and the result that will change simultaneously calculates, handles and send LED to show.
This voltage table selects for use AT89S52 as main control singlechip, is a kind of low-power consumption, high-performance CMOS 8 8-digit microcontrollers.AT89S52 adopts the high-density nonvolatile memory technology of atmel corp to make; Compatibility standard MCS-51 order set and 80C52 pin configuration; Its outstanding feature be sheet include 8K byte ISP (In System Programmable) can be erasable repeatedly 1000 times the Flash program storage; Make it rewriting, no longer rely on special-purpose programming tool, also need not pull down chip from circuit board the storer internal program.
A/D converter is selected 16 successive approximation converter LTC1865 of Linear company.It is the serial analog to digital converter of difference input, two-channel 2-4 50ksps, single power supply, can be in-40 ℃～+ 125 ℃ temperature range reliably working, have characteristics such as high-speed, high precision, low-power consumption.
The data output interface of LTC1865 adopts the SPI mode, because AT89S52 does not have special SPI mouth, therefore needs to simulate with general purpose I/O pin.SCK with P2.0 and LTC1865 is connected, and comes regularly cleer and peaceful set P2.0 through software.Connect the SDI mouth with P2.1, LTC1865 is write the selection that configuration words is realized input mode.Connect SDO with P2.2, be responsible for reading in of data.With P2.3 as chip selection signal.Concrete connection is referring to shown in Figure 2.The beginning of LTC1865 change-over period is triggered by the rising edge of CONV pin; Again CONV is dragged down after having passed through one period switching time; Export a time clock through the variation of software control single-chip microcomputer P2.0 pin high-low level this moment, reads in data from ground of P2.2 mouth simultaneously, in this course; Single-chip microcomputer can be regarded a main device that has the SPI interface as, and two pins of P2.0 and P2.2 have served as SCLK and two pins of MISO in the SPI interface respectively.When 16 bit data run through finish after, promptly stop P2.0 mouth pulse output.
The range Implementation of automatic transformation and the course of work: utilize voltage attenuation input buffer, operational amplifier and No. 2 electronic switches to combine and realize the range auto-conversion function with the scm software programming.The hardware circuit diagram of its realization is as shown in Figure 3, and wherein AD822BP is two precision operational-amplifiers of a single supply produced of ADI, low-power consumption, rail-to-rail output (full press output), and input impedance is 1013 Ω, and common-mode rejection ratio is 80dB; MAX4602 is the cmos analog switch that a conducting resistance is merely 2.5 Ω, and there are four normal open switch inside, and each switch all can be handled the rail-to-rail simulating signal, has low-power consumption, small size, reliability advantages of higher.
Range conversion automatically begins by just establishing range, till selecting suitable range.A/D change-over circuit input reference signal is 0～5V; The higher limit of voltage to be measured is 400V, and AT89S52 is 0 to switch controlling signal RS_SWH_1, the setting of RS_SWH_2 initial value, and promptly 2 way switch are off-state; Voltage attenuation input buffering this moment level is confirmed 100 times of attenuated input signals by R1 and R2 dividing potential drop; And the computing amplifier stage is in the voltage follow state, and enlargement factor is 1, thereby guarantees that A/D converted input signal is between 0～4V; Single-chip microcomputer is confirmed the state of RS_SWH_1, RS_SWH_2 again according to the result of A/D conversion, thereby measured signal is on the suitable range, and each parameters relationship of range automatic switching circuit and setting are referring to table 1.
The automatic conversion parameter of table 1 range concerns and table is set
| Range | RS_SWH_1 | Attenuation coefficient | RS_SWH_2 | Enlargement factor | The A/D input |
| The first value of establishing | 0 | 100 | 0 | 1 | 0～4V |
| 0～0.4V | 1 | 1 | 1 | 10 | 0～4V |
| 0.4～4V | 1 | 1 | 0 | 1 | 0.4～4V |
| 4V～40V | 0 | 100 | 1 | 10 | 0.4～4V |
| 40V～400V | 0 | 100 | 0 | 1 | 0.4～4V |
The program that range is changed the high accuracy number voltage table automatically adopts modular design, uses the C language.Program is made up of master routine, range conversion routine, A/D conversion routine, LED display subroutine.
Single-chip microcomputer powers on and carries out initial work earlier, and the initial value of switch controlling signal is set, and promptly RS_SWH_1, RS_SWH_2 are 0; Then start the A/D conversion to measured signal; Call the range converse routine thereupon and judge whether range is suitable,, then reset the numerical value of switch controlling signal, restart the A/D conversion if be not suitable for, suitable until range; Output data send LED to show.Its software design process flow diagram is as shown in Figure 4.
The automatic conversion routine of range is called after accomplishing one-shot measurement by master routine; When this program is called, up-to-date measurement data and the threshold value of just establishing range (maximum amount journey) are compared, if exceed threshold value; Then for overflow or the double sampling gap between measured signal become suddenly big; The scope that exceeds original suitable range needs the state according to switch controlling signal, takes corresponding Disposal Measures; If in normal range, also need further with other range threshold ratio; If current maximum amount journey is suitable range, promptly exportable video data; Otherwise select an only range and sampling in other three ranges, realization flow is as shown in Figure 5.Become big for fear of measured signal between the double sampling gap, exceed the input reference signal of LTC1865, taked holding circuit like D1, D2 among Fig. 3 suddenly.
Claims (1)
1. automatic converting digital voltage table of range; It is characterized in that comprising input circuit, range change-over circuit, A/D converter, main control singlechip, LED display module and power module; Wherein, Input circuit, range change-over circuit, A/D converter, main control singlechip and LED display module link to each other in proper order, and input circuit, range change-over circuit, A/D converter, main control singlechip and LED display module all are connected with power module respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200010556U CN202256477U (en) | 2011-01-05 | 2011-01-05 | Digital voltmeter adaptable for automatically switching range |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011200010556U CN202256477U (en) | 2011-01-05 | 2011-01-05 | Digital voltmeter adaptable for automatically switching range |
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| CN202256477U true CN202256477U (en) | 2012-05-30 |
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| CN2011200010556U Expired - Fee Related CN202256477U (en) | 2011-01-05 | 2011-01-05 | Digital voltmeter adaptable for automatically switching range |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102854376A (en) * | 2012-09-28 | 2013-01-02 | 上海理工大学 | Digital voltmeter and measuring method thereof |
| CN103226163A (en) * | 2013-03-05 | 2013-07-31 | 丽水职业技术学院 | Alternating and direct current universal millivoltmeter circuit |
| CN105067866A (en) * | 2015-08-14 | 2015-11-18 | 武汉华中数控股份有限公司 | General voltage test device |
| CN106338639A (en) * | 2015-07-06 | 2017-01-18 | 河北工业大学 | Pulse peak voltage measurement and display device |
| CN107121589A (en) * | 2017-04-18 | 2017-09-01 | 国网浙江省电力公司衢州供电公司 | A kind of digital 220kV electroscope for power transmission line |
| CN107257229A (en) * | 2017-06-30 | 2017-10-17 | 安徽大恒能源科技有限公司 | A kind of high-precision measuring method based on photovoltaic module data monitoring system |
-
2011
- 2011-01-05 CN CN2011200010556U patent/CN202256477U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102854376A (en) * | 2012-09-28 | 2013-01-02 | 上海理工大学 | Digital voltmeter and measuring method thereof |
| CN103226163A (en) * | 2013-03-05 | 2013-07-31 | 丽水职业技术学院 | Alternating and direct current universal millivoltmeter circuit |
| CN106338639A (en) * | 2015-07-06 | 2017-01-18 | 河北工业大学 | Pulse peak voltage measurement and display device |
| CN105067866A (en) * | 2015-08-14 | 2015-11-18 | 武汉华中数控股份有限公司 | General voltage test device |
| CN105067866B (en) * | 2015-08-14 | 2017-10-31 | 武汉华中数控股份有限公司 | A kind of common voltage test device |
| CN107121589A (en) * | 2017-04-18 | 2017-09-01 | 国网浙江省电力公司衢州供电公司 | A kind of digital 220kV electroscope for power transmission line |
| CN107257229A (en) * | 2017-06-30 | 2017-10-17 | 安徽大恒能源科技有限公司 | A kind of high-precision measuring method based on photovoltaic module data monitoring system |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120530 Termination date: 20140105 |