CN2237844Y - Digital intelligent temp. transducer - Google Patents
Digital intelligent temp. transducer Download PDFInfo
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- CN2237844Y CN2237844Y CN 95229306 CN95229306U CN2237844Y CN 2237844 Y CN2237844 Y CN 2237844Y CN 95229306 CN95229306 CN 95229306 CN 95229306 U CN95229306 U CN 95229306U CN 2237844 Y CN2237844 Y CN 2237844Y
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- Analogue/Digital Conversion (AREA)
Abstract
The utility model relates to a digital intelligent temperature transducer, comprising a computer circuit, a cold junction compensator, a multiplex switcher, an amplifying sampling holder, an A/D digital-analog converter, a control circuit, two paths of D/A analog-digital converter and a V1 voltage-current conversion circuit. The cold junction compensator and thermal couple temperature signal is connected with the A/D through the multiplex switcher and through the amplifying sampling holder, the output end of the A/D and the date input end of the D/A are both connected with the data bus line of the computer, and the output end of the D/A is connected with the input end of the voltage-current conversion circuit. The input end of the control circuit is connected with the output end of the computer, and the output end of the control circuit is connected with the channel selection end of the multiplex switcher. Therefore, the nonlinear compensation has high precision, and two paths of temperature can be converted with temperature digital display.
Description
The utility model relates to the thermocouple temperature transmitter, belongs to the electronic measuring instrument field.
Analog thermocouple temperature transmitter is used for a long time, because the restriction of its device level, makes that the zero stability of complete machine is poor, nonlinear compensation trouble, precision be low, and a complete machine has only an output loop, does not have temperature to show.
In view of above-mentioned, the utility model will provide a kind of digital temperature transmitter, and its available mathematical method solution nonlinear compensation and zero point, a complete machine had the input and output of two-way temperature, is equivalent to two analogue instruments, and has temperature digital to show from normal moveout correction.
For realizing this purpose, the utility model adopts following technical proposals:
A kind of digital intelligent temperature transmitter comprises cabinet and microcomputer circuit, it is characterized in that: it also comprises junction compensator, multi-channel switcher, amplification sampling maintenance, analog to digital conversion, control, two-way digital-to-analog conversion and all circuit of voltage current transformation, and wherein: described microcomputer circuit is connected to display and keyboard by parallel interface; Described junction compensator is an operational amplifier, one two thermocouple output signals of input termination, and another input end grounding, its output connects the signal input part of described multi-channel switcher; The output of described multi-channel switcher connects the input of described analog to digital converter through described amplification sampling hold circuit, the data output of described analog to digital converter connects the data bus of described microcomputer circuit, the data input port of described digital to analog converter connects the data bus of described microcomputer circuit, the delivery outlet of described digital to analog converter connects the input of described voltage current transformating circuit, the input of described control circuit connects the output of described microcomputer circuit, and the output of described control circuit connects the channel selecting end of described multi-channel switcher.
Two-way thermocouple temperature signal is after control circuit is selected, send into analog to digital converter with the cold junction compensation signal through multi-channel switcher, amplification sampling hold circuit, the result of conversion send display after by MICROCOMPUTER PROCESSING, and after digital to analog converter converts analog quantity to again by the voltage current transformating circuit output current signal.
Below in conjunction with drawings and Examples the utility model is described in detail.
Fig. 1 is a circuit composition frame chart of the present utility model;
Fig. 2 is circuit theory diagrams of the present utility model.
The utility model comprises cabinet and circuit.See also Fig. 1, circuit of the present utility model is made up of junction compensator, multi-channel switcher, amplification sampling hold circuit, analog to digital converter, microcomputer circuit, control circuit, two-way digital to analog converter and voltage current transformating circuit.Wherein: microcomputer circuit is connected to display and keyboard by parallel interface; The output of junction compensator connects the signal input part of multi-channel switcher; The output of multi-channel switcher connects the input of analog to digital converter through the amplification sampling hold circuit, the data output of analog to digital converter connects the data bus of microcomputer circuit, the data input port of digital to analog converter connects the data bus of microcomputer circuit, the delivery outlet of digital to analog converter connects the input of voltage current transformating circuit, the input of control circuit connects the output of microcomputer circuit, and the output of control circuit connects the channel selecting end of multi-channel switcher.
See also Fig. 2, multi-channel switcher U1 adopts AD7502; Amplify sampling hold circuit by AD524 amplifier U2, LM308 amplifier U3, the AD582 sampling holder U4 of serial connection constitute successively; Analog to digital converter U5 adopts AD574A; Microcomputer circuit by 8031 microprocessor U7,27C64 ROM (read-only memory) U10,6116 random access memory U11, LS373 address latch U12, LS138 address decoder U13,8155 parallel interface U27, display DISP, keyboard KEY routinely connection constitute; 7402 rejection gate U16 and LS75 latch U6 constitute the control circuit of the input channel of selecting multi-channel switcher U1; Digital to analog converter U8 and U9 adopt 0832, LF356 operational amplifier U25, uA741 operational amplifier U24 and two-stage drive triode U23, U22 are connected in series the formation voltage current transformating circuit successively, and digital to analog converter U9, LF356 operational amplifier U18, uA741 operational amplifier U19, two-stage drive triode U20, U21 constitute second way weighted-voltage D/A converter and the voltage current transformating circuit; UA741 operational amplifier U29 constitutes junction compensator.
In Fig. 2: the output of AD581 thermocouple U26 and AD590 thermocouple U28 and connect after connect the inverting input of operational amplifier U29 in the junction compensator, its in-phase input end ground connection, its output connects S4 and the S5 input end of multi-channel switcher U1.The input end S port of multi-channel switcher U1 meets two-way thermocouple temperature signal INPUT, and its output is sent into amplifier U2 from 4 and 12 pin.Output 9 pin of amplifier U2 connect 3 pin of amplifier U3.Output 6 pin of amplifier U3 connect 1 pin of sampling holder U4.The output of sampling holder U4 connects 13 pin of analog to digital converter U5.Data output DB0～DB11 of analog to digital converter U5 connects the data bus of microcomputer circuit, the PSEN of microprocessor U7, RD through LS08 with the door U14 with after, one the tunnel connects the R/C pin of analog to digital converter U5 through LS00 Sheffer stroke gate U15, another road and WR signal connect the CE pin of analog to digital converter U5 behind Sheffer stroke gate U15, the P13 pin of microprocessor U7 connects the A0 pin of analog to digital converter U5, the STATUS pin of analog to digital converter U5 connects the input end of LS125 triple gate U17, and the output of this triple gate meets data line D7.In each way mould conversion output, data port DI0～DI7 of digital to analog converter U8 (or U9) connects the data bus of microcomputer circuit, 2 pin connect the WR pin of microprocessor U7, and 11,12 pin connect the input pin 2 and 3 of operational amplifier U25 (or U18) in the voltage current transformating circuit.In the output pin of address decoder U13: 7 pin connect the CE pin of parallel interface U27, and 9～15 pin connect the CS pin of analog to digital converter U5, the CE pin of random access memory U11,1 pin of digital to analog converter U9,1 pin of digital to analog converter U8, the control end of triple gate U17, the input of rejection gate U16, the CE pin of ROM (read-only memory) U10 respectively.The WR signal of microprocessor U7 and the output of 14 pin of address decoder U13 connect 4 pin of latch U6 behind rejection gate U16, the data port D0 of latch U6～D2 connects the data bus of microcomputer circuit, and output terminal Q0～Q2 of latch U6 connects 16,1 and 3 pin of multi-channel switcher U1 respectively.
Narrate principle of work below:
Solidify the management application software that is used for calculation process and control among the ROM (read-only memory) U10, and stored electric thermo-couple temperature-thermoelectrical potential curve mathematic model of setting up with the mode of curve fitting.The temperature signal of two-way thermocouple is after latch U6 selects one, the temperature compensation signal of sending with junction compensator enters multi-channel switcher U1 together, after amplifier U2 and amplifier U3 amplification, send among the sampling holder U4 again and keep, the analog signals of sampling holder U4 output is converted to ten binary digit signals through analog to digital converter U5, after this digital data carries out computing and processing by microprocessor U7, convert the two-way analog quantity to through two-way digital to analog converter U8 and U9 respectively on the one hand, again by voltage current transformating circuit output two-way 4～20mA current signal, send display DISP through parallel interface U27 on the other hand, by the measured temperature of display DISP display digit amount.Keyboard KEY is used for the switching and the instrument panel operation of input channel.
The utlity model has following advantages:
1. owing to adopt microcomputer circuit, thus the measured value of digital quantity can be shown intuitively, can Adopt curve-fitting method, improve the nonlinear compensation precision;
2. the change that can finish simultaneously the two-way temperature signal is sent;
3. employing cold-junction compensation has overcome the unsettled shortcoming of analog instrument zero.
Claims (2)
1. a digital intelligent temperature transmitter comprises cabinet and microcomputer circuit, it is characterized in that: it also comprises junction compensator, multi-channel switcher, amplification sampling maintenance, analog to digital conversion, control, two-way digital-to-analog conversion and all circuit of voltage current transformation, wherein:
Described microcomputer circuit is connected to display and keyboard by parallel interface;
Described junction compensator is an operational amplifier, one two thermocouple output signals of input termination, and another input end grounding, its output connects the signal input part of described multi-channel switcher;
The output of described multi-channel switcher connects the input of described analog to digital converter through described amplification sampling hold circuit, the data output of described analog to digital converter connects the data bus of described microcomputer circuit, the data input port of described digital to analog converter connects the data bus of described microcomputer circuit, the delivery outlet of described digital to analog converter connects the input of described voltage current transformating circuit, the input of described control circuit connects the output of described microcomputer circuit, and the output of described control circuit connects the channel selecting end of described multi-channel switcher.
2. digital intelligent temperature transmitter as claimed in claim 1, it is characterized in that: described control circuit is a latch, its control input end connects the write signal and the address decode signal of described microcomputer circuit, its data input pin connects the data bus of described microcomputer circuit, and its data output end connects the channel selecting end of described multi-channel switcher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95229306 CN2237844Y (en) | 1995-12-27 | 1995-12-27 | Digital intelligent temp. transducer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95229306 CN2237844Y (en) | 1995-12-27 | 1995-12-27 | Digital intelligent temp. transducer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2237844Y true CN2237844Y (en) | 1996-10-16 |
Family
ID=33874544
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95229306 Expired - Fee Related CN2237844Y (en) | 1995-12-27 | 1995-12-27 | Digital intelligent temp. transducer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2237844Y (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100392683C (en) * | 2002-09-06 | 2008-06-04 | 罗斯蒙德公司 | Low power physical layer for a bus in an industrial transmitter |
| CN102032955A (en) * | 2010-11-15 | 2011-04-27 | 蚌埠市双利电器有限责任公司 | Electronic tuning method of temperature sensor |
| CN102879018A (en) * | 2012-09-18 | 2013-01-16 | 杭州电子科技大学 | Platinum resistance and analogous current transducing circuit |
| CN106840438A (en) * | 2017-02-23 | 2017-06-13 | 西安交通大学 | A kind of W-Re film temperature sensor cold junction compensation structure based on fluid channel |
| CN108474693A (en) * | 2016-01-18 | 2018-08-31 | 三菱电机株式会社 | Measurement device and assay method |
| CN114485737A (en) * | 2021-12-31 | 2022-05-13 | 浙江中控技术股份有限公司 | Transmitter with self-calibration function and current loop |
-
1995
- 1995-12-27 CN CN 95229306 patent/CN2237844Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100392683C (en) * | 2002-09-06 | 2008-06-04 | 罗斯蒙德公司 | Low power physical layer for a bus in an industrial transmitter |
| CN102032955A (en) * | 2010-11-15 | 2011-04-27 | 蚌埠市双利电器有限责任公司 | Electronic tuning method of temperature sensor |
| CN102879018A (en) * | 2012-09-18 | 2013-01-16 | 杭州电子科技大学 | Platinum resistance and analogous current transducing circuit |
| CN108474693A (en) * | 2016-01-18 | 2018-08-31 | 三菱电机株式会社 | Measurement device and assay method |
| CN108474693B (en) * | 2016-01-18 | 2020-05-01 | 三菱电机株式会社 | Measuring apparatus and measuring method |
| CN106840438A (en) * | 2017-02-23 | 2017-06-13 | 西安交通大学 | A kind of W-Re film temperature sensor cold junction compensation structure based on fluid channel |
| CN106840438B (en) * | 2017-02-23 | 2019-04-12 | 西安交通大学 | A kind of W-Re film temperature sensor cold junction compensation structure based on fluid channel |
| CN114485737A (en) * | 2021-12-31 | 2022-05-13 | 浙江中控技术股份有限公司 | Transmitter with self-calibration function and current loop |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |