CN104467794A - Signal acquisition circuit - Google Patents
Signal acquisition circuit Download PDFInfo
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- CN104467794A CN104467794A CN201410815327.4A CN201410815327A CN104467794A CN 104467794 A CN104467794 A CN 104467794A CN 201410815327 A CN201410815327 A CN 201410815327A CN 104467794 A CN104467794 A CN 104467794A
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Abstract
The invention discloses a signal acquisition circuit which comprises a first signal conditioning circuit, a second signal conditioning circuit, a third signal conditioning circuit, a fourth signal conditioning circuit and an A/D conversion chip. The first signal conditioning circuit, the second signal conditioning circuit, the third signal conditioning circuit and the fourth signal conditioning circuit are connected with the input end of the A/D conversion chip through I/O input interfaces respectively. The output end of the A/D conversion chip is connected with a magnetic coupling isolation chip. The A/D conversion chip is powered by a 5 V reference voltage circuit. Through the magnetic coupling isolation chip, the isolation effect between a whole analog input circuit and a single-chip microcomputer is enhanced; through the single A/D conversion chip, the conversion speed is higher; by designing the multiple conditioning circuits, the sampling speed is high, and stability is higher; the whole circuit is simple in structure, low in cost, longer in service life and higher in stability.
Description
Technical field
The present invention relates to the refrigeration system control field of central air-conditioning, specifically a kind of signal acquisition circuit.
Background technology
In central air conditioning system, refrigeration system is essential is also vital part, in order to realize chilled water pump efficient, adjust fast and accurately, need to gather and the signal of conversion sensor within the fastest time, adjust timely to make.In the signal acquisition circuit adopted in current refrigeration system, the chip of employing and circuit all more complicated, not only processing speed is affected, and use cost is higher, all has a certain impact to the freezing efficiency of Air-condition system control and effect.
Summary of the invention
The invention provides a kind of signal acquisition circuit, effectively can improve the speed of signals collecting and conversion, greatly reduce costs.
The present invention is by the following technical solutions: signal acquisition circuit, comprise the first signal conditioning circuit, secondary signal modulate circuit, the 3rd signal conditioning circuit, the 4th signal conditioning circuit and A/D conversion chip, the first described signal conditioning circuit, secondary signal modulate circuit, the 3rd signal conditioning circuit, the 4th signal conditioning circuit connect A/D conversion chip input respectively by an I/O input interface, the output of A/D conversion chip connects a magnetic coupling isolating chip, and A/D conversion chip provides power supply by a 5V reference voltage circuit.
Further, described A/D conversion chip is chip ADS8341.
Further, described magnetic coupling isolating chip is ADUM1411.
Further, described 5V reference voltage circuit comprises electric capacity C9, electric capacity C9 one end connects the 8th pin and chip MAX6164 the 6th pin of A/D chip ADS8341 respectively, electric capacity C9 other end ground connection, electric capacity C10 is in parallel with electric capacity C9, chip MAX6164 second pin connects 5V voltage, chip MAX6164 earth terminal ground connection.
Further, the first described signal conditioning circuit comprises resistance R18, resistance R18 mono-termination 4-20mA current signal input, resistance R18 other end ground connection, electric capacity C12 is in parallel with resistance R18, diode D9 positive pole connects 4-20mA current signal input, diode D9 minus earth, the 13 pin connecting resistance R13 one end of amplifier U1, the resistance R13 other end is connecting resistance R16 one end respectively, electric capacity C11 one end, slide rheostat R17 one end, another termination 5V voltage of resistance R16, the electric capacity C11 other end and slide rheostat R17 other end ground connection, 12 pin of amplifier U1 connects 4-20mA current signal input by resistance R14, amplifier U1 the 12 pin is by resistance R15 ground connection, 14 pin of amplifier U1 connects the 13 pin of amplifier U1 by resistance R12, 14 pin of amplifier U1 connects the tenth pin of amplifier U1 by resistance R11, 9th pin of amplifier U1 is by slide rheostat R10 ground connection, 8th pin of amplifier U1 is by resistance R9 ground connection, 8th pin of amplifier U1 connects the 5th pin of A/D chip ADS8341 by resistance R8.
Further, described secondary signal modulate circuit comprises resistance R29, resistance R29 mono-termination 4-20mA current signal input, resistance R29 other end ground connection, electric capacity C14 is in parallel with resistance R29, diode D10 positive pole connects 4-20mA current signal input, diode D10 minus earth, the 13 pin connecting resistance R24 one end of amplifier U2, the resistance R24 other end is connecting resistance R27 one end respectively, electric capacity C13 one end, slide rheostat R28 one end, another termination 5V voltage of resistance R27, the electric capacity C13 other end and slide rheostat R28 other end ground connection, 12 pin of amplifier U2 connects 4-20mA current signal input by resistance R25, amplifier U2 the 12 pin is by resistance R26 ground connection, 14 pin of amplifier U2 connects the 13 pin of amplifier U2 by resistance R23, 14 pin of amplifier U2 connects the tenth pin of amplifier U1 by resistance R22, 9th pin of amplifier U2 is by slide rheostat R21 ground connection, 8th pin of amplifier U2 is by resistance R20 ground connection, 8th pin of amplifier U2 connects the 4th pin of A/D chip ADS8341 by resistance R19.
Further, the 3rd described signal conditioning circuit comprises resistance R40, resistance R40 mono-termination 4-20mA current signal input, resistance R40 other end ground connection, electric capacity C16 is in parallel with resistance R40, diode D11 positive pole connects 4-20mA current signal input, diode D11 minus earth, the 13 pin connecting resistance R35 one end of amplifier U3, the resistance R35 other end is connecting resistance R38 one end respectively, electric capacity C15 one end, slide rheostat R39 one end, another termination 5V voltage of resistance R38, the electric capacity C15 other end and slide rheostat R39 other end ground connection, 12 pin of amplifier U3 connects 4-20mA current signal input by resistance R36, amplifier U3 the 12 pin is by resistance R37 ground connection, 14 pin of amplifier U3 connects the 13 pin of amplifier U3 by resistance R34, 14 pin of amplifier U3 connects the tenth pin of amplifier U3 by resistance R33, 9th pin of amplifier U3 is by slide rheostat R32 ground connection, 8th pin of amplifier U3 is by resistance R31 ground connection, 8th pin of amplifier U3 connects the 3rd pin of A/D chip ADS8341 by resistance R30.
Further, the 4th described signal conditioning circuit comprises resistance R51, resistance R51 mono-termination 4-20mA current signal input, resistance R51 other end ground connection, electric capacity C18 is in parallel with resistance R51, diode D12 positive pole connects 4-20mA current signal input, diode D12 minus earth, the 13 pin connecting resistance R46 one end of amplifier U4, the resistance R46 other end is connecting resistance R49 one end respectively, electric capacity C17 one end, slide rheostat R50 one end, another termination 5V voltage of resistance R49, the electric capacity C17 other end and slide rheostat R50 other end ground connection, 12 pin of amplifier U4 connects 4-20mA current signal input by resistance R47, amplifier U4 the 12 pin is by resistance R48 ground connection, 14 pin of amplifier U4 connects the 13 pin of amplifier U4 by resistance R45, 14 pin of amplifier U4 connects the tenth pin of amplifier U4 by resistance R44, 9th pin of amplifier U4 is by slide rheostat R43 ground connection, 8th pin of amplifier U4 is by resistance R42 ground connection, 8th pin of amplifier U4 connects the 2nd pin of A/D chip ADS8341 by resistance R41.
The invention has the beneficial effects as follows: utilize magnetic coupling isolating chip, enhance the isolation effect between whole analog input circuit and single-chip microcomputer; Have employed single A/D chip, conversion speed is faster; Design multiple modulate circuit, not only sample rate is fast, and stability is also better; Whole circuit structure is simple, and cost is lower, longer service life, and stability is better.
Accompanying drawing explanation
Fig. 1 is circuit theory diagrams of the present invention.
Embodiment
Signal acquisition circuit as shown in Figure 1, comprise first, second, third, fourth 4 road signal conditioning circuits and A/D conversion chip ADS8341,9th pin of A/D chip ADS8341 connects 5V voltage, the 1st pin ground connection of A/D chip ADS8341,10th, the 11 pin ground connection of A/D chip ADS8341, A/D chip ADS8341 the 12nd, 13,14,15,16 pins meet isolating chip ADUM1411.
8th pin of A/D chip ADS8341 connects 5V a reference source, 5V a reference source comprises electric capacity C9, electric capacity C9 one end connects the 8th pin and chip MAX6164 the 6th pin of A/D chip ADS8341 respectively, electric capacity C9 other end ground connection, electric capacity C10 is in parallel with electric capacity C9, chip MAX6164 second pin connects 5V voltage, chip MAX6164 earth terminal ground connection.
First signal conditioning circuit comprises resistance R18, resistance R18 mono-termination 4-20mA current signal input, resistance R18 other end ground connection, electric capacity C12 is in parallel with resistance R18, diode D9 positive pole connects 4-20mA current signal input, diode D9 minus earth, the 13 pin connecting resistance R13 one end of amplifier U1, the resistance R13 other end is connecting resistance R16 one end respectively, electric capacity C11 one end, slide rheostat R17 one end, another termination 5V voltage of resistance R16, the electric capacity C11 other end and slide rheostat R17 other end ground connection, 12 pin of amplifier U1 connects 4-20mA current signal input by resistance R14, amplifier U1 the 12 pin is by resistance R15 ground connection, 14 pin of amplifier U1 connects the 13 pin of amplifier U1 by resistance R12, 14 pin of amplifier U1 connects the tenth pin of amplifier U1 by resistance R11, 9th pin of amplifier U1 is by slide rheostat R10 ground connection, 8th pin of amplifier U1 is by resistance R9 ground connection, 8th pin of amplifier U1 connects the 5th pin of A/D chip ADS8341 by resistance R8.
Secondary signal modulate circuit comprises resistance R29, resistance R29 mono-termination 4-20mA current signal input, resistance R29 other end ground connection, electric capacity C14 is in parallel with resistance R29, diode D10 positive pole connects 4-20mA current signal input, diode D10 minus earth, the 13 pin connecting resistance R24 one end of amplifier U2, the resistance R24 other end is connecting resistance R27 one end respectively, electric capacity C13 one end, slide rheostat R28 one end, another termination 5V voltage of resistance R27, the electric capacity C13 other end and slide rheostat R28 other end ground connection, 12 pin of amplifier U2 connects 4-20mA current signal input by resistance R25, amplifier U2 the 12 pin is by resistance R26 ground connection, 14 pin of amplifier U2 connects the 13 pin of amplifier U2 by resistance R23, 14 pin of amplifier U2 connects the tenth pin of amplifier U1 by resistance R22, 9th pin of amplifier U2 is by slide rheostat R21 ground connection, 8th pin of amplifier U2 is by resistance R20 ground connection, 8th pin of amplifier U2 connects the 4th pin of A/D chip ADS8341 by resistance R19.
3rd signal conditioning circuit comprises resistance R40, resistance R40 mono-termination 4-20mA current signal input, resistance R40 other end ground connection, electric capacity C16 is in parallel with resistance R40, diode D11 positive pole connects 4-20mA current signal input, diode D11 minus earth, the 13 pin connecting resistance R35 one end of amplifier U3, the resistance R35 other end is connecting resistance R38 one end respectively, electric capacity C15 one end, slide rheostat R39 one end, another termination 5V voltage of resistance R38, the electric capacity C15 other end and slide rheostat R39 other end ground connection, 12 pin of amplifier U3 connects 4-20mA current signal input by resistance R36, amplifier U3 the 12 pin is by resistance R37 ground connection, 14 pin of amplifier U3 connects the 13 pin of amplifier U3 by resistance R34, 14 pin of amplifier U3 connects the tenth pin of amplifier U3 by resistance R33, 9th pin of amplifier U3 is by slide rheostat R32 ground connection, 8th pin of amplifier U3 is by resistance R31 ground connection, 8th pin of amplifier U3 connects the 3rd pin of A/D chip ADS8341 by resistance R30.
4th signal conditioning circuit comprises resistance R51, resistance R51 mono-termination 4-20mA current signal input, resistance R51 other end ground connection, electric capacity C18 is in parallel with resistance R51, diode D12 positive pole connects 4-20mA current signal input, diode D12 minus earth, the 13 pin connecting resistance R46 one end of amplifier U4, the resistance R46 other end is connecting resistance R49 one end respectively, electric capacity C17 one end, slide rheostat R50 one end, another termination 5V voltage of resistance R49, the electric capacity C17 other end and slide rheostat R50 other end ground connection, 12 pin of amplifier U4 connects 4-20mA current signal input by resistance R47, amplifier U4 the 12 pin is by resistance R48 ground connection, 14 pin of amplifier U4 connects the 13 pin of amplifier U4 by resistance R45, 14 pin of amplifier U4 connects the tenth pin of amplifier U4 by resistance R44, 9th pin of amplifier U4 is by slide rheostat R43 ground connection, 8th pin of amplifier U4 is by resistance R42 ground connection, 8th pin of amplifier U4 connects the 2nd pin of A/D chip ADS8341 by resistance R41.
After on-the-spot transducer collects signal; send 4-20mA current signal; after signal conditioning circuit receives signal, the voltage signal being converted into 0-5V after the process such as over-sampling, filtering, protection, difference, amplification arrives chip ADS8341, eventually passes magnetic coupling isolating chip and is transferred to single-chip microcomputer.
Except structure of the present invention, all the other are prior art.
The above is the preferred embodiment of the present invention, and for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications are also regarded as protection scope of the present invention.
Claims (8)
1. signal acquisition circuit, it is characterized in that, comprise the first signal conditioning circuit, secondary signal modulate circuit, the 3rd signal conditioning circuit, the 4th signal conditioning circuit and A/D conversion chip, the first described signal conditioning circuit, secondary signal modulate circuit, the 3rd signal conditioning circuit, the 4th signal conditioning circuit connect A/D conversion chip input respectively by an I/O input interface, the output of A/D conversion chip connects a magnetic coupling isolating chip, and A/D conversion chip provides power supply by a 5V reference voltage circuit.
2. signal acquisition circuit according to claim 1, is characterized in that, described A/D conversion chip is chip ADS8341.
3. signal acquisition circuit according to claim 1, is characterized in that, described magnetic coupling isolating chip is ADUM1411.
4. the signal acquisition circuit according to claim 1-3 any one, it is characterized in that, described 5V reference voltage circuit comprises electric capacity C9, electric capacity C9 one end connects the 8th pin and chip MAX6164 the 6th pin of A/D chip ADS8341 respectively, electric capacity C9 other end ground connection, electric capacity C10 is in parallel with electric capacity C9, and chip MAX6164 second pin connects 5V voltage, chip MAX6164 earth terminal ground connection.
5. signal acquisition circuit according to claim 4, it is characterized in that, the first described signal conditioning circuit comprises resistance R18, resistance R18 mono-termination 4-20mA current signal input, resistance R18 other end ground connection, electric capacity C12 is in parallel with resistance R18, diode D9 positive pole connects 4-20mA current signal input, diode D9 minus earth, the 13 pin connecting resistance R13 one end of amplifier U1, the resistance R13 other end is connecting resistance R16 one end respectively, electric capacity C11 one end, slide rheostat R17 one end, another termination 5V voltage of resistance R16, the electric capacity C11 other end and slide rheostat R17 other end ground connection, 12 pin of amplifier U1 connects 4-20mA current signal input by resistance R14, amplifier U1 the 12 pin is by resistance R15 ground connection, 14 pin of amplifier U1 connects the 13 pin of amplifier U1 by resistance R12, 14 pin of amplifier U1 connects the tenth pin of amplifier U1 by resistance R11, 9th pin of amplifier U1 is by slide rheostat R10 ground connection, 8th pin of amplifier U1 is by resistance R9 ground connection, 8th pin of amplifier U1 connects the 5th pin of A/D chip ADS8341 by resistance R8.
6. signal acquisition circuit according to claim 4, it is characterized in that, described secondary signal modulate circuit comprises resistance R29, resistance R29 mono-termination 4-20mA current signal input, resistance R29 other end ground connection, electric capacity C14 is in parallel with resistance R29, diode D10 positive pole connects 4-20mA current signal input, diode D10 minus earth, the 13 pin connecting resistance R24 one end of amplifier U2, the resistance R24 other end is connecting resistance R27 one end respectively, electric capacity C13 one end, slide rheostat R28 one end, another termination 5V voltage of resistance R27, the electric capacity C13 other end and slide rheostat R28 other end ground connection, 12 pin of amplifier U2 connects 4-20mA current signal input by resistance R25, amplifier U2 the 12 pin is by resistance R26 ground connection, 14 pin of amplifier U2 connects the 13 pin of amplifier U2 by resistance R23, 14 pin of amplifier U2 connects the tenth pin of amplifier U1 by resistance R22, 9th pin of amplifier U2 is by slide rheostat R21 ground connection, 8th pin of amplifier U2 is by resistance R20 ground connection, 8th pin of amplifier U2 connects the 4th pin of A/D chip ADS8341 by resistance R19.
7. signal acquisition circuit according to claim 4, it is characterized in that, the 3rd described signal conditioning circuit comprises resistance R40, resistance R40 mono-termination 4-20mA current signal input, resistance R40 other end ground connection, electric capacity C16 is in parallel with resistance R40, diode D11 positive pole connects 4-20mA current signal input, diode D11 minus earth, the 13 pin connecting resistance R35 one end of amplifier U3, the resistance R35 other end is connecting resistance R38 one end respectively, electric capacity C15 one end, slide rheostat R39 one end, another termination 5V voltage of resistance R38, the electric capacity C15 other end and slide rheostat R39 other end ground connection, 12 pin of amplifier U3 connects 4-20mA current signal input by resistance R36, amplifier U3 the 12 pin is by resistance R37 ground connection, 14 pin of amplifier U3 connects the 13 pin of amplifier U3 by resistance R34, 14 pin of amplifier U3 connects the tenth pin of amplifier U3 by resistance R33, 9th pin of amplifier U3 is by slide rheostat R32 ground connection, 8th pin of amplifier U3 is by resistance R31 ground connection, 8th pin of amplifier U3 connects the 3rd pin of A/D chip ADS8341 by resistance R30.
8. signal acquisition circuit according to claim 4, it is characterized in that, the 4th described signal conditioning circuit comprises resistance R51, resistance R51 mono-termination 4-20mA current signal input, resistance R51 other end ground connection, electric capacity C18 is in parallel with resistance R51, diode D12 positive pole connects 4-20mA current signal input, diode D12 minus earth, the 13 pin connecting resistance R46 one end of amplifier U4, the resistance R46 other end is connecting resistance R49 one end respectively, electric capacity C17 one end, slide rheostat R50 one end, another termination 5V voltage of resistance R49, the electric capacity C17 other end and slide rheostat R50 other end ground connection, 12 pin of amplifier U4 connects 4-20mA current signal input by resistance R47, amplifier U4 the 12 pin is by resistance R48 ground connection, 14 pin of amplifier U4 connects the 13 pin of amplifier U4 by resistance R45, 14 pin of amplifier U4 connects the tenth pin of amplifier U4 by resistance R44, 9th pin of amplifier U4 is by slide rheostat R43 ground connection, 8th pin of amplifier U4 is by resistance R42 ground connection, 8th pin of amplifier U4 connects the 2nd pin of A/D chip ADS8341 by resistance R41.
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| CN201410815327.4A CN104467794B (en) | 2014-12-25 | 2014-12-25 | Signal acquisition circuit |
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| CN201410815327.4A CN104467794B (en) | 2014-12-25 | 2014-12-25 | Signal acquisition circuit |
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| CN104467794A true CN104467794A (en) | 2015-03-25 |
| CN104467794B CN104467794B (en) | 2017-10-24 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109001566A (en) * | 2018-06-29 | 2018-12-14 | 国网河南省电力公司襄城县供电公司 | A kind of intelligent warning board for transformer substations |
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| CN203719811U (en) * | 2014-01-14 | 2014-07-16 | 南京信息工程大学 | Weak voltage signal detection device of micro-voltage sensor |
| CN203732101U (en) * | 2014-03-14 | 2014-07-23 | 西安科技大学 | Signal collection and transmission device for portable coal mine machinery equipment performance testing instrument |
| CN204349962U (en) * | 2014-12-25 | 2015-05-20 | 李钢 | Signal acquisition circuit |
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2014
- 2014-12-25 CN CN201410815327.4A patent/CN104467794B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05244137A (en) * | 1992-02-28 | 1993-09-21 | Casio Comput Co Ltd | Timing extraction method and circuit |
| CN1558190A (en) * | 2004-01-16 | 2004-12-29 | 湖南科技大学 | Digital vibration and impact sensor |
| CN203719811U (en) * | 2014-01-14 | 2014-07-16 | 南京信息工程大学 | Weak voltage signal detection device of micro-voltage sensor |
| CN203732101U (en) * | 2014-03-14 | 2014-07-23 | 西安科技大学 | Signal collection and transmission device for portable coal mine machinery equipment performance testing instrument |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109001566A (en) * | 2018-06-29 | 2018-12-14 | 国网河南省电力公司襄城县供电公司 | A kind of intelligent warning board for transformer substations |
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| CN104467794B (en) | 2017-10-24 |
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