CN107505061A - A kind of platinum resistance temperature measuring device in double-current source - Google Patents
A kind of platinum resistance temperature measuring device in double-current source Download PDFInfo
- Publication number
- CN107505061A CN107505061A CN201710243452.6A CN201710243452A CN107505061A CN 107505061 A CN107505061 A CN 107505061A CN 201710243452 A CN201710243452 A CN 201710243452A CN 107505061 A CN107505061 A CN 107505061A
- Authority
- CN
- China
- Prior art keywords
- pin
- resistance
- operational amplifier
- current source
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/18—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer
- G01K7/20—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer in a specially-adapted circuit, e.g. bridge circuit
- G01K7/21—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer in a specially-adapted circuit, e.g. bridge circuit for modifying the output characteristic, e.g. linearising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K2215/00—Details concerning sensor power supply
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The present invention relates to a kind of platinum resistance temperature measuring device in double-current source to include：RTD PT100, three-wire system lead and temperature measurement circuit；The three-wire system lead includes：Connecting lead wire r01, connecting lead wire r02, connecting lead wire r03；The temperature measurement circuit includes：Reference resistance R0, two-way equivalent current source circuit and amplification output circuit；The RTD PT100 is installed on tested point, is connected with temperature measurement circuit by three-wire system lead；The present invention is directed in traditional platinum resistance temperature measuring device, the error that resistance, induced voltage on connecting lead wire introduce, and the error that circuit element temperature drift introduces, give the technical scheme of the Pt Resistance Temperature Measuring Circuit in double-current source, offset for the error on lead, error caused by the temperature drift of the electronic component of equivalent current source circuit can also be offset simultaneously, reduce influence of the external interference to circuit output, the measurement accuracy of Pt Resistance Temperature Measuring Circuit is improved, various high-resolution hydrocode demands can be met.
Description
Technical field
The present invention relates to field of circuit technology, more particularly to a kind of platinum resistance temperature measuring device in double-current source.
Background technology
RTD is a kind of thermal resistance type temperature sensor, because its temperature-measuring range is big, stable performance, it is reproducible the characteristics of
And it is widely used in temperature measurement circuit.For platinum resistor temperature measuring, generally use unbalanced bridge varies with temperature RTD
Electric signal output, then send single-chip microcomputer to carry out computing after amplified and A/D conversion., can be first using unbalance bridge circuit
Ensure bridge balance during beginning temperature, but when lead is longer, lead resistance is very important, it will influence the measurement of temperature measurement circuit
As a result, high-acruracy survey requirement can not be met.
Using constant flow source measuring circuit temperature, the influence of circuit topology counteracting lead resistance can be passed through.But in complicated electromagnetism
The interference such as induced voltage can be also produced in environment, on longer connecting lead wire, influences the measurement result of temperature measurement circuit.It is in addition, electric
The parameter of circuit component can be varied with temperature and changed, that is, temperature drift phenomenon occurs, and cause the deviation and ripple of circuit output
It is dynamic, error is brought to temperature-measuring results, influences measurement accuracy.
The content of the invention
In view of above-mentioned analysis, the present invention is intended to provide a kind of platinum resistance temperature measuring device in double-current source, existing to solve
There are the problems such as the error of the interference introduced in technology on connecting lead wire and circuit parameter wave zone.
The purpose of the present invention is mainly achieved through the following technical solutions：
In one embodiment based on apparatus of the present invention, there is provided a kind of platinum resistance temperature measuring device in double-current source, bag
Include：RTD PT100, three-wire system lead and temperature measurement circuit；Three-wire system lead includes：Connecting lead wire r01, connecting lead wire r02, connect
Meet lead r03；Temperature measurement circuit includes：Reference resistance R0, two-way equivalent current source circuit and amplification output circuit；The RTD
PT100 is installed on tested point, is connected with temperature measurement circuit by three-wire system lead；
It is first output end of two-way equivalent current source circuit and connecting lead wire r01 1 end, the first of amplification output circuit defeated
Enter end to be connected；Second output end of two-way equivalent current source circuit and the second input of resistance R0 pin 1, amplification output circuit
End is connected；
Reference resistance R0 pin 2 is connected with connecting lead wire r02 1 end；RTD Pt100 pin 1 and connecting lead wire
R01 2 ends are connected, pin 2 is connected with connecting lead wire r02 2 ends, connecting lead wire r03 2 ends, connecting lead wire r03 1 termination
Ground；
The first input end of amplification output circuit is connected with the first output end of the two-way equivalent current source circuit, amplification
Second output end of output circuit is connected with the second output end of the two-way equivalent current source circuit, amplification output circuit it is defeated
Go out end externally output thermometric sampled result.
In based on another of apparatus of the present invention embodiment, two-way equivalent current source circuit includes：Operational amplifier
N2A, N2B, N2C, N2D, resistance R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, electric capacity C4；Resistance R1 pin 1 is with R2's
Pin 1 is the input of two-way equivalent current source circuit, accesses reference voltage；Operational amplifier N2A output end and resistance R7
Pin 2, resistance R9 pin 1 be connected, operational amplifier N2A reverse input end and resistance R5 pin 2, resistance R7 draw
Pin 1 is connected, and operational amplifier N2A positive input is connected with resistance R1 pin 2, resistance R3 pin 1, operational amplifier
N2A reverse input end is connected with resistance R7 pin 1, and is grounded by resistance R5；Operational amplifier N2B positive input
The pin 1 of pin 2, resistance R4 with resistance R2 is connected, and operational amplifier N2B reverse input end resistance R8 pin 1 is connected,
And be grounded by resistance R6, operational amplifier N2B output end is connected with resistance R8 pin 2, resistance R10 pin 1；Computing
Amplifier N2C output end is connected with resistance R3 pin 2, operational amplifier N2C reverse input end, operational amplifier N2D
Reverse input end be connected with resistance R4 pin 2, operational amplifier N2D output end, operational amplifier N2C positive input
End is connected with resistance R9 pin 2, electric capacity C4 pin 2, operational amplifier N2D positive input and resistance R10 pin
2nd, electric capacity C4 pin 1 is connected；Operational amplifier N2C positive input exports for the first of two-way equivalent current source circuit
End；Operational amplifier N2D positive input is the second output end of two-way equivalent current source circuit.
In based on another of apparatus of the present invention embodiment, two-way equivalent current source circuit includes：Four-way computing is put
Big device N2, resistance R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, electric capacity C4, resistance R1 pin 1 and R2 pin 1 are double
The input access reference voltage of road equivalent current source circuit, operational amplifier N2 pin 2 and resistance R7 pin 2, resistance
R9 pin 1 is connected, and operational amplifier N2 pin 3 is connected with resistance R5 pin 2, resistance R7 pin 1, operational amplifier
N2 pin 4 is connected with resistance R1 pin 2, resistance R3 pin 1, operational amplifier N2 pin 8 and resistance R2 pin
2nd, resistance R4 pin 1 is connected, and operational amplifier N2 pin 9 is connected with resistance R6 pin 2, resistance R8 pin 1, computing
Amplifier N2 pin 10 is connected with resistance R8 pin 2, resistance R10 pin 1, operational amplifier N2 pin 12 and resistance
R3 pin 2, operational amplifier N2 pin 13 are connected, and operational amplifier N2 pin 19 is put with resistance R4 pin 2, computing
Big device N2 pin 20 is connected, and operational amplifier N2 pin 14 is connected with resistance R9 pin 2, electric capacity C4 pin 2, computing
Amplifier N2 pin 18 is connected with resistance R10 pin 2, electric capacity C4 pin 1；Operational amplifier N2 pin 14 is two-way
First output end of equivalent current source circuit；Operational amplifier N2 pin 18 exports for the second of two-way equivalent current source circuit
End.
In based on another of apparatus of the present invention embodiment, amplification output circuit includes operational amplifier N3 and resistance
R11, the operational amplifier N3 positive input are the first input end of amplification output circuit, and operational amplifier N3's is reverse
Input is the second input of amplification output circuit, and resistance R11 is connected between operational amplifier N3 two RG pins, institute
State RG pins to be used to connect outside gain control resistance, operational amplifier N3 output end is the output end of amplification output circuit.
In based on another of apparatus of the present invention embodiment, temperature measurement circuit is powered by two-way ± 15V power supplys, power supply+
15V ends are connected with operational amplifier N2A positive power source terminal, operational amplifier N3 positive power source terminal, -15V the ends of power supply and computing
Amplifier N2A negative power end, operational amplifier N3 negative power end is connected, the GND ends of power supply and operational amplifier N3 ginseng
Examine end, resistance R5 pin 1, resistance R6 pin 1, connecting lead wire r03 1 end are connected.
In based on another of apparatus of the present invention embodiment, temperature measurement circuit is powered by two-way ± 15V power supplys, power supply+
15V ends are connected with four-way operational amplifier N2 positive power source terminal, operational amplifier N3 positive power source terminal, -15V the ends of power supply with
Operational amplifier N2 negative power end, operational amplifier N3 negative power end is connected, and the GND ends of power supply are with operational amplifier N3's
Reference edge, resistance R5 pin 1, resistance R6 pin 1, connecting lead wire r03 1 end are connected.
In based on another of apparatus of the present invention embodiment, temperature measurement circuit also includes voltage conversion circuit, voltage conversion
Circuit is used to supply voltage being converted to reference voltage, there is provided gives two-way equivalent current source circuit.
In based on another of apparatus of the present invention embodiment, voltage conversion circuit include power supply chip N1 and electric capacity C1,
C2, C3, the input of the power supply chip N1 are connected with electric capacity C1 pin 2, electric capacity C2 pin 2, and power supply chip N1's connects
Ground terminal is connected with electric capacity C1 pin 1, electric capacity C2 pin 2, power supply chip N1 output end and electric capacity C3 pin 2, two-way
The input of equivalent current source circuit is connected；+ 15V the ends of power supply and power supply chip N1 input, electric capacity C1 pin 2, electricity
The pin 2 for holding C2 is connected, the GND ends of power supply and power supply chip N1 earth terminal, electric capacity C1 pin 1, electric capacity C2 pin 1,
Electric capacity C3 pin 1 is connected.
In based on another of apparatus of the present invention embodiment, resistance R0 resistance is equal to RTD Pt100 and surveyed in temperature
Measure the resistance of the lower limit of scope.
The present invention has the beneficial effect that：
Embodiments of the invention are directed in traditional platinum resistance temperature measuring device, and the resistance, induced voltage on connecting lead wire introduce
Error, and the error that circuit element temperature drift introduces gives the technical side of the Pt Resistance Temperature Measuring Circuit in double-current source
Case, offset for the error on lead, while error caused by the temperature drift of the electronic component of equivalent current source circuit
Also it can be offset, reduce influence of the external interference to circuit output, improve the measurement accuracy of Pt Resistance Temperature Measuring Circuit, can
To meet various high-resolution hydrocode demands.
Other features and advantages of the present invention will illustrate in the following description, also, partial become from specification
Obtain it is clear that or being understood by implementing the present invention.The purpose of the present invention and other advantages can be by the explanations write
Specifically noted structure is realized and obtained in book, claims and accompanying drawing.
Brief description of the drawings
Accompanying drawing is only used for showing the purpose of specific embodiment, and is not considered as limitation of the present invention, in whole accompanying drawing
In, identical reference symbol represents identical part.
Fig. 1 is the structural representation of the embodiment of the present invention 1；
Fig. 2 is the structural representation of the embodiment of the present invention 2；
Fig. 3 is the structural representation of the embodiment of the present invention 3.
Embodiment
The preferred embodiments of the present invention are specifically described below in conjunction with the accompanying drawings, wherein, accompanying drawing forms the application part, and
It is used for the principle for explaining the present invention together with embodiments of the present invention.
According to the specific embodiment 1 of the present invention, as shown in figure 1, disclosing a kind of platinum resistor temperature measuring in double-current source
Device, specifically include：RTD PT100, three-wire system lead, temperature measurement circuit；Three-wire system lead includes：Connecting lead wire r01, connection
Lead r02, connecting lead wire r03；Temperature measurement circuit includes：Reference resistance R0, two-way equivalent current source circuit and amplification output circuit；
It is first output end of two-way equivalent current source circuit and connecting lead wire r01 1 end, the first of amplification output circuit defeated
Enter end to be connected；Second output end of two-way equivalent current source circuit and the second input of resistance R0 pin 1, amplification output circuit
End is connected；
Reference resistance R0 pin 2 is connected with connecting lead wire r02 1 end；RTD Pt100 pin 1 and connecting lead wire
R01 2 ends are connected, pin 2 is connected with connecting lead wire r02 2 ends, connecting lead wire r03 2 ends, connecting lead wire r03 1 termination
Ground；
The first input end of amplification output circuit is connected with the first output end of two-way equivalent current source circuit, amplification output
Second output end of circuit is connected with the second output end of two-way equivalent current source circuit, and the output end of amplification output circuit is external
Export thermometric sampled result.
RTD PT100 is installed on tested point；Two-way equivalent current source circuit drives RTD and reference resistance respectively, supports
Disappear circuit error；Amplification output circuit scales up the voltage difference of two-way equivalent current source circuit output, exports thermometric
Sampled result.
As shown in Fig. 2 the embodiment of the present invention 2, two-way equivalent current source circuit includes：Operational amplifier N2A, N2B, N2C,
N2D, resistance R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, electric capacity C4；Resistance R1 pin 1 and R2 pin 1 are two-way
The input of equivalent current source circuit, access reference voltage；Operational amplifier N2A output end and resistance R7 pin 2, resistance
R9 pin 1 is connected, and operational amplifier N2A reverse input end is connected with resistance R5 pin 2, resistance R7 pin 1, computing
Amplifier N2A positive input is connected with resistance R1 pin 2, resistance R3 pin 1, and operational amplifier N2A's is reverse defeated
Enter end with resistance R7 pin 1 to be connected, and be grounded by resistance R5；Operational amplifier N2B positive input is with resistance R2's
Pin 2, resistance R4 pin 1 are connected, operational amplifier N2B reverse input end and resistance R6 pin 2, resistance R8 pin
1 is connected, and is grounded by resistance R6, operational amplifier N2B output end and the phase of pin 1 of resistance R8 pin 2, resistance R10
Even；Operational amplifier N2C output end is connected with resistance R3 pin 2, operational amplifier N2C reverse input end, and computing is put
Big device N2D reverse input end is connected with resistance R4 pin 2, operational amplifier N2D output end, operational amplifier N2C's
Positive input is connected with resistance R9 pin 2, electric capacity C4 pin 2, operational amplifier N2D positive input and resistance
R10 pin 2, electric capacity C4 pin 1 are connected；Operational amplifier N2C positive input is two-way equivalent current source circuit
First output end；Operational amplifier N2D positive input is the second output end of two-way equivalent current source circuit.
Amplification output circuit includes operational amplifier N3 and resistance R11, and operational amplifier N3 positive input is amplification
The first input end of output circuit, operational amplifier N3 reverse input end are the second input of amplification output circuit, resistance
R11 is connected between operational amplifier N3 two RG pins, and RG pins are used to connect outside gain control resistance, operation amplifier
Device N3 output end is the output end of amplification output circuit, externally exports thermometric sampled result.In the present embodiment, N3 AD620.
Specifically, resistance R0 resistance is equal to RTD Pt100 under initial temperature (i.e. the lower limit of temperature measurement range)
Resistance.Resistance R1, R2, R3, R4, R5, R6, R7, R8 resistance all same, the present embodiment elect 10k Ω as, this 8 resistance
Resistance can be changed, but need to ensure that resistance is identical；Resistance R9, resistance R10 resistance all same, the present embodiment elect 2.5k as
Ω, the resistance of the two resistance can be changed, but need to ensure that resistance is identical, while the benchmark electricity of two-way equivalent current source circuit
Pressure and resistance R9, resistance R10 the ratio between resistance should be milliampere level, it is not possible to excessive, the otherwise output current of equivalent current source
It is excessive, obvious temperature rise can be produced on RTD, influence measurement result.
Wherein, temperature measurement circuit is powered by two-way ± 15V power supplys ,+15V the ends of power supply and operational amplifier N2A positive supply
End, operational amplifier N3 positive power source terminal are connected, -15V the ends of power supply and operational amplifier N2A negative power end, operation amplifier
Device N3 pin 4 is connected, the GND ends of power supply and operational amplifier N3 pin 5, resistance R5 pin 1, resistance R6 pin 1,
Connecting lead wire r03 1 end is connected；
Temperature measurement circuit also includes voltage conversion circuit, and voltage conversion circuit is used to supply voltage being converted to reference voltage,
It is supplied to two-way equivalent current source circuit；Voltage conversion circuit includes power supply chip N1 and electric capacity C1, C2, C3, power supply chip N1
Input be connected with electric capacity C1 pin 2, electric capacity C2 pin 2, power supply chip N1 earth terminal and electric capacity C1 pin 1,
Electric capacity C2 pin 2 is connected, power supply chip N1 output end and the input of electric capacity C3 pin 2, two-way equivalent current source circuit
End is connected；+ 15V the ends of power supply are connected with power supply chip N1 input, electric capacity C1 pin 2, electric capacity C2 pin 2, power supply
GND ends be connected with power supply chip N1 earth terminal, electric capacity C1 pin 1, electric capacity C2 pin 1, electric capacity C3 pin 1.
Specifically, power supply chip N1 is voltage conversion chip, the ADR4525 chips of AD companies is selected, by 15V voltage conversions
For 2.5V reference voltages.Other modes can also be used to obtain reference voltage, reference voltage may not be 2.5V, using other
After voltage class, R9, R10 resistance are changed.But need to ensure that the resistance of this 2 resistance is identical, while power supply chip N1
Output voltage and resistance R9, resistance R10 the ratio between resistance should be milliampere level, it is not possible to excessive, otherwise equivalent current source
Output current is excessive, obvious temperature rise can be produced on RTD, influence measurement result.
Specifically, C1, C2, C3 and C4 capacitance adjust between 1nF to 100nF, preferably 10nF, strobe, filter
Except interference.
As shown in figure 3, in an alternative embodiment of the invention 3, two-way equivalent current source circuit has selected four-way fortune
Amplifier chip N2 is calculated, four tunnel operational amplifier modules are integrated with a chip, described equivalent current source is built, such as schemes
Shown in 2, preferably OP4177：Two-way equivalent current source circuit include four-way operational amplifier N2, resistance R1, R2, R3, R4, R5,
R6, R7, R8, R9, R10, electric capacity C4, reference voltage by the input of two-way equivalent electric source circuit and resistance R1 pin 1 with
R2 pin 1 is connected, and operational amplifier N2 pin 2 is connected with resistance R7 pin 2, resistance R9 pin 1, operational amplifier
N2 pin 3 is connected with resistance R5 pin 2, resistance R7 pin 1, operational amplifier N2 pin 4 and resistance R1 pin
2nd, resistance R3 pin 1 is connected, and operational amplifier N2 pin 8 is connected with resistance R2 pin 2, resistance R4 pin 1, computing
Amplifier N2 pin 9 is connected with resistance R6 pin 2, resistance R8 pin 1, operational amplifier N2 pin 10 and resistance R8
Pin 2, resistance R10 pin 1 be connected, operational amplifier N2 pin 12 and resistance R3 pin 2, operational amplifier N2
Pin 13 is connected, and operational amplifier N2 pin 19 is connected with resistance R4 pin 2, operational amplifier N2 pin 20, computing
Amplifier N2 pin 14 is connected with resistance R9 pin 2, electric capacity C4 pin 2, operational amplifier N2 pin 18 and resistance
R10 pin 2, electric capacity C4 pin 1 are connected；Operational amplifier N2 pin 14 is first defeated for two-way equivalent current source circuit
Go out end, the first input end at 1 end, amplification output circuit with connecting lead wire r01 is connected；Operational amplifier N2 pin 18 is double
Second output end of road equivalent current source circuit, the second input of pin 1, amplification output circuit with resistance R0 are connected.
During work, two-way ± 15V power supplys are power supply chip N1, operational amplifier N2, operational amplifier N3 power；Power supply core
Piece N1 is by voltage on the basis of 15V voltage conversions and exports；Operational amplifier N2 works in negative-feedback state, pin 3 and pin 4
Voltage is equal, pin 8 is equal with the voltage of pin 9, pin 13 is equal with the voltage of pin 14, the voltage of pin 18 and pin 19
Equal, pin 3, pin 4, pin 8, pin 9, pin 13, pin 14, pin 18,19 equal no current of pin flow in or out；Electricity
Resistance R1, resistance R3, resistance R5, resistance R7, resistance R9 and operational amplifier N2 N2A, N2C part collectively constituted one it is equivalent
Current source, produces constant current on resistance R9, and electric current flows through resistance R9, connecting lead wire r01, RTD Pt100, connection successively
Lead r03, finally flow back to the GND ends of two-way ± 15V power supplys；Resistance R2, resistance R4, resistance R6, resistance R8, resistance R10 and fortune
N2B, N2D part for calculating amplifier N2 have collectively constituted another identical equivalent current source, and phase is produced on resistance R10
Deng constant current, electric current flows through resistance R10, resistance R0, connecting lead wire r02, connecting lead wire r03, finally flows back to two-way successively
The GND ends of ± 15V power supplys.
Operational amplifier N3 reverse input end for power supply GND ends voltage be equal to resistance R0 both end voltages it is poor, connect
Lead r02 both end voltages are poor, connecting lead wire r03 both end voltage difference sums；Operational amplifier N3 positive input is for power supply
The voltage at GND ends is equal to connecting lead wire r01 both end voltages are poor, RTD Pt100 both end voltages are poor, connecting lead wire r03 both ends electricity
Pressure difference sum.Because three connecting lead wire length of three-wire system lead are identical, path is identical, therefore the resistance on three connecting lead wires
It is identical.The output current of two equivalent current sources is also identical simultaneously, so connecting lead wire r01, connecting lead wire r02 voltage difference are equal
It is equal, when asking for the voltage difference between operational amplifier N3 positive input and reverse input end, the electricity on connecting lead wire
Pressure is cancelled out each other.Thus, the voltage difference between operational amplifier N3 positive input and reverse input end is equal to RTD
Pt100 both end voltage subtractives go the voltage difference at resistance R0 both ends, be also just proportional to RTD Pt100 and resistance R0 resistance it
Difference.RTD Pt100 resistance changes with temperature linearity, and temperature is higher, and RTD Pt100 resistance is also higher.Resistance R0
Resistance be equal to resistances of the RTD Pt100 under initial temperature.Therefore, the difference of RTD Pt100 and resistance R0 resistance is just
It is proportional to the difference of tested point temperature and initial temperature.In summary, the output voltage of operational amplifier N3 pin 6, which is proportional to, treats
The difference of measuring point temperature and initial temperature, the temperature information of tested point is externally outputed exactly.
Induced voltage or other interference signals may be produced in complex electromagnetic environment, on three-wire system lead.But length
The interference that the voltage that senses on identical, three connecting lead wires of path identical is identical, introduces is also identical, is calculating operational amplifier
During voltage difference between N3 positive input and reverse input end, these induced voltages and interference signals cancel one another will not
Interference is delivered on the output voltage of operational amplifier N3 output ends, avoids the introducing of error.
When the temperature is changed, the characterisitic parameter of electronic component may change, and influence the output of circuit, that is, produce temperature
Degree drift.In the temperature measurement circuit, resistance R1, resistance R3, resistance R5, resistance R7, resistance R9, operational amplifier N2 are formed
Equivalent current source, resistance R2, resistance R4, resistance R6, resistance R8, resistance R10, operational amplifier N2 N2B, N2D part are common
The circuit structure of another equivalent current source of composition is identical with selected component.Two-way current source in temperature change and
When producing parameter error, the change of its output current is also basically identical, can cancel each other, and reduces temperature drift to temperature measurement circuit
The influence of measurement result, improve measurement accuracy.
Beneficial effect：The present invention is directed in traditional platinum resistance temperature measuring device, and the resistance, induced voltage on connecting lead wire introduce
Error, and the error that circuit element temperature drift introduces gives the technical side of the Pt Resistance Temperature Measuring Circuit in double-current source
Case, offset for the error on lead, while error caused by the temperature drift of the electronic component of equivalent current source circuit
Also it can be offset, reduce influence of the external interference to circuit output, improve the measurement accuracy of Pt Resistance Temperature Measuring Circuit, can
To meet various high-resolution hydrocode demands.
The foregoing is only a preferred embodiment of the present invention, but protection scope of the present invention be not limited thereto,
Any one skilled in the art the invention discloses technical scope in, the change or replacement that can readily occur in,
It should all be included within the scope of the present invention.
Claims (9)
- A kind of 1. platinum resistance temperature measuring device in double-current source, it is characterised in that including：RTD PT100, three-wire system lead and survey Circuit temperature；The three-wire system lead includes：Connecting lead wire r01, connecting lead wire r02, connecting lead wire r03；The temperature measurement circuit bag Include：Reference resistance R0, two-way equivalent current source circuit and amplification output circuit；The RTD PT100 is installed on tested point, with Temperature measurement circuit is connected by three-wire system lead；It is first output end of the two-way equivalent current source circuit and connecting lead wire r01 1 end, the first of amplification output circuit defeated Enter end to be connected；Second output end of two-way equivalent current source circuit and the second input of resistance R0 pin 1, amplification output circuit End is connected；The pin 2 of the reference resistance R0 is connected with connecting lead wire r02 1 end；The pin 1 of the RTD Pt100 is with being connected Lead r01 2 ends are connected, pin 2 is connected with connecting lead wire r02 2 ends, connecting lead wire r03 2 ends, and the 1 of connecting lead wire r03 End ground connection；The output end of the amplification output circuit externally exports thermometric sampled result.
- A kind of 2. platinum resistance temperature measuring device in double-current source as claimed in claim 1, it is characterised in that the two-way equivalent electric Current source circuit includes：Operational amplifier N2A, N2B, N2C, N2D, resistance R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, electricity Hold C4；Resistance R1 pin 1 and the input that R2 pin 1 is two-way equivalent current source circuit, access reference voltage；Computing is put Big device N2A output end is connected with resistance R7 pin 2, resistance R9 pin 1, operational amplifier N2A reverse input end and Resistance R5 pin 2, resistance R7 pin 1 are connected, operational amplifier N2A positive input and resistance R1 pin 2, resistance R3 pin 1 is connected, and operational amplifier N2A reverse input end is connected with resistance R7 pin 1, and is grounded by resistance R5； Operational amplifier N2B positive input is connected with resistance R2 pin 2, resistance R4 pin 1, and operational amplifier N2B's is anti- It is connected to input with resistance R8 pin 1, and is grounded by resistance R6, operational amplifier N2B output end is with resistance R8's Pin 2, resistance R10 pin 1 are connected；Operational amplifier N2C output end and resistance R3 pin 2, operational amplifier N2C Reverse input end is connected, operational amplifier N2D reverse input end and resistance R4 pin 2, operational amplifier N2D output end It is connected, operational amplifier N2C positive input is connected with resistance R9 pin 2, electric capacity C4 pin 2, operational amplifier N2D Positive input be connected with resistance R10 pin 2, electric capacity C4 pin 1；Operational amplifier N2C positive input is double First output end of road equivalent current source circuit；Operational amplifier N2D positive input is two-way equivalent current source circuit Second output end.
- A kind of 3. platinum resistance temperature measuring device in double-current source as claimed in claim 1, it is characterised in that the two-way equivalent electric Current source circuit includes：Four-way operational amplifier N2, resistance R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, electric capacity C4, electricity Hinder R1 pin 1 and access reference voltage with R2 pin 1 for the input of two-way equivalent current source circuit, operational amplifier N2's Pin 2 is connected with resistance R7 pin 2, resistance R9 pin 1, operational amplifier N2 pin 3 and resistance R5 pin 2, electricity The pin 1 for hindering R7 is connected, and operational amplifier N2 pin 4 is connected with resistance R1 pin 2, resistance R3 pin 1, operation amplifier Device N2 pin 8 is connected with resistance R2 pin 2, resistance R4 pin 1, operational amplifier N2 pin 9 and drawing for resistance R6 Pin 2, resistance R8 pin 1 are connected, and operational amplifier N2 pin 10 is connected with resistance R8 pin 2, resistance R10 pin 1, Operational amplifier N2 pin 12 is connected with resistance R3 pin 2, operational amplifier N2 pin 13, and operational amplifier N2's draws Pin 19 is connected with resistance R4 pin 2, operational amplifier N2 pin 20, operational amplifier N2 pin 14 and drawing for resistance R9 Pin 2, electric capacity C4 pin 2 are connected, and operational amplifier N2 pin 18 is connected with resistance R10 pin 2, electric capacity C4 pin 1； Operational amplifier N2 pin 14 is the first output end of two-way equivalent current source circuit；Operational amplifier N2 pin 18 is double Second output end of road equivalent current source circuit.
- A kind of 4. platinum resistance temperature measuring device in double-current source as described in claim 1 or 2 or 3, it is characterised in that the amplification It is amplification output circuit that output circuit, which includes operational amplifier N3 and resistance R11, the operational amplifier N3 positive input, First input end, operational amplifier N3 reverse input end is the second input of amplification output circuit, and resistance R11 is connected to Between operational amplifier N3 two RG pins, the RG pins are used to connect outside gain control resistance, operational amplifier N3 Output end be amplification output circuit output end.
- 5. a kind of platinum resistance temperature measuring device in double-current source as claimed in claim 2, it is characterised in that temperature measurement circuit is by two-way ± 15V power supplys are powered ,+15V the ends of power supply and the positive power source terminal phase of operational amplifier N2A positive power source terminal, operational amplifier N3 Even, -15V the ends of power supply are connected with operational amplifier N2A negative power end, operational amplifier N3 negative power end, the GND of power supply End is connected with operational amplifier N3 reference edge, resistance R5 pin 1, resistance R6 pin 1, connecting lead wire r03 1 end.
- 6. a kind of platinum resistance temperature measuring device in double-current source as claimed in claim 3, it is characterised in that temperature measurement circuit is by two-way ± 15V power supplys are powered ,+15V the ends of power supply and four-way operational amplifier N2 positive power source terminal, operational amplifier N3 positive supply End is connected, and -15V the ends of power supply are connected with operational amplifier N2 negative power end, operational amplifier N3 negative power end, power supply GND ends are connected with operational amplifier N3 reference edge, resistance R5 pin 1, resistance R6 pin 1, connecting lead wire r03 1 end.
- A kind of 7. platinum resistance temperature measuring device in double-current source as described in claim any one of 1-3, it is characterised in that the survey Circuit temperature also includes voltage conversion circuit, and voltage conversion circuit is used to supply voltage being converted to reference voltage, there is provided to two-way Equivalent current source circuit.
- A kind of 8. platinum resistance temperature measuring device in double-current source as claimed in claim 7, it is characterised in that the voltage conversion electricity Road includes power supply chip N1 and electric capacity C1, C2, C3, the input of the power supply chip N1 and electric capacity C1 pin 2, electric capacity C2 Pin 2 is connected, and power supply chip N1 earth terminal is connected with electric capacity C1 pin 1, electric capacity C2 pin 2, and power supply chip N1's is defeated Go out end with electric capacity C3 pin 2, the input of two-way equivalent current source circuit to be connected；+ 15V the ends of power supply are with power supply chip N1's Input, electric capacity C1 pin 2, electric capacity C2 pin 2 are connected, the GND ends of power supply and power supply chip N1 earth terminal, electric capacity C1 Pin 1, electric capacity C2 pin 1, electric capacity C3 pin 1 be connected.
- A kind of 9. platinum resistance temperature measuring device in double-current source as claimed in claim 6, it is characterised in that the resistance of the resistance R0 Value is equal to resistances of the RTD Pt100 in the lower limit of temperature measurement range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710243452.6A CN107505061B (en) | 2017-04-14 | 2017-04-14 | A kind of platinum resistance temperature measuring device in double-current source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710243452.6A CN107505061B (en) | 2017-04-14 | 2017-04-14 | A kind of platinum resistance temperature measuring device in double-current source |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107505061A true CN107505061A (en) | 2017-12-22 |
| CN107505061B CN107505061B (en) | 2019-06-18 |
Family
ID=60679372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710243452.6A Active CN107505061B (en) | 2017-04-14 | 2017-04-14 | A kind of platinum resistance temperature measuring device in double-current source |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107505061B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108692823A (en) * | 2018-04-04 | 2018-10-23 | 镇江赛尔尼柯自动化有限公司 | A kind of PT100 temperature transmitter devices based on embedded technology |
| CN110440945A (en) * | 2019-08-27 | 2019-11-12 | 太原合创自动化有限公司 | High Precision Low Temperature floats the double matching constant current resource temperature measurement circuits of discrete |
| CN110987223A (en) * | 2019-11-27 | 2020-04-10 | 山东航天电子技术研究所 | Improved high-precision platinum resistor temperature measuring circuit |
| CN113589046A (en) * | 2021-09-06 | 2021-11-02 | 天津津航计算技术研究所 | High-precision resistance signal acquisition circuit applied to aviation electromechanical products |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5858428A (en) * | 1981-10-02 | 1983-04-07 | Yamatake Honeywell Co Ltd | Three-wire temperature sensor |
| JPS63273026A (en) * | 1987-05-01 | 1988-11-10 | Yamatake Honeywell Co Ltd | Input circuit of temperature measuring instrument |
| CN2055253U (en) * | 1989-05-08 | 1990-03-28 | 中国建筑科学研究院空气调节研究所 | Precise constant-current source type thermal resistance temp. transducer |
| CN2692646Y (en) * | 2003-09-29 | 2005-04-13 | 中兴通讯股份有限公司 | Thermoresistor temp measuring circuit |
| CN102829888A (en) * | 2011-06-15 | 2012-12-19 | 上海电器科学研究院 | Method for eliminating three-wire heating resistor measurement errors |
-
2017
- 2017-04-14 CN CN201710243452.6A patent/CN107505061B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5858428A (en) * | 1981-10-02 | 1983-04-07 | Yamatake Honeywell Co Ltd | Three-wire temperature sensor |
| JPS63273026A (en) * | 1987-05-01 | 1988-11-10 | Yamatake Honeywell Co Ltd | Input circuit of temperature measuring instrument |
| CN2055253U (en) * | 1989-05-08 | 1990-03-28 | 中国建筑科学研究院空气调节研究所 | Precise constant-current source type thermal resistance temp. transducer |
| CN2692646Y (en) * | 2003-09-29 | 2005-04-13 | 中兴通讯股份有限公司 | Thermoresistor temp measuring circuit |
| CN102829888A (en) * | 2011-06-15 | 2012-12-19 | 上海电器科学研究院 | Method for eliminating three-wire heating resistor measurement errors |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108692823A (en) * | 2018-04-04 | 2018-10-23 | 镇江赛尔尼柯自动化有限公司 | A kind of PT100 temperature transmitter devices based on embedded technology |
| CN110440945A (en) * | 2019-08-27 | 2019-11-12 | 太原合创自动化有限公司 | High Precision Low Temperature floats the double matching constant current resource temperature measurement circuits of discrete |
| CN110440945B (en) * | 2019-08-27 | 2024-02-20 | 太原合创自动化有限公司 | High-precision low-temperature drift discrete type double-matching constant current source temperature measuring circuit |
| CN110987223A (en) * | 2019-11-27 | 2020-04-10 | 山东航天电子技术研究所 | Improved high-precision platinum resistor temperature measuring circuit |
| CN110987223B (en) * | 2019-11-27 | 2021-03-16 | 山东航天电子技术研究所 | Improved high-precision platinum resistor temperature measuring circuit |
| CN113589046A (en) * | 2021-09-06 | 2021-11-02 | 天津津航计算技术研究所 | High-precision resistance signal acquisition circuit applied to aviation electromechanical products |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107505061B (en) | 2019-06-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11187729B2 (en) | Current sensor chip with magnetic field sensor | |
| CN102305885B (en) | Isolation type voltage sensor | |
| CN101109662B (en) | Thermal resistance temperature surveying circuit | |
| CN107505061A (en) | A kind of platinum resistance temperature measuring device in double-current source | |
| CN203037265U (en) | Temperature compensating circuit | |
| CN202075059U (en) | Novel platinum resistor temperature measurement module | |
| CN106679841A (en) | Temperature detecting device and temperature detecting method | |
| CN106443159B (en) | Current detection chip | |
| CN106679842A (en) | Temperature measuring method and circuit adopting reference voltage compensation technology | |
| CN105890793A (en) | Three-wire Pt100 platinum resistance temperature measurement circuit | |
| CN105300269B (en) | A kind of wireless accurate strain gauge means and a kind of wireless accurate strain measurement method | |
| CN102478422A (en) | Zero drift simulation calibrating method and device thereof | |
| US7622903B2 (en) | EMI rejection for temperature sensing diodes | |
| CN105277292A (en) | Temperature measurement device | |
| CN110412485A (en) | A kind of output current detection circuit | |
| CN206740271U (en) | A kind of temperature measuring circuit | |
| CN206695925U (en) | A kind of multichannel RTD thermal resistance measurement modules | |
| CN206020612U (en) | A kind of power amplifier parallel connection debugging apparatus | |
| CN202171514U (en) | circuit by utilizing double-constant current source | |
| CN214041538U (en) | Current and voltage detection circuit based on single chip microcomputer | |
| Filipský et al. | Design and first test of the new synchronous 200 Hz system for unsteady pressure field measurement | |
| TWI436069B (en) | Current measuring apparatus for power supply | |
| Maiti et al. | Novel remote measurement technique using resistive sensor as grounded load in an opamp based V-to-I converter | |
| CN108507695A (en) | A kind of atomic air chamber temperature checking method based on locking phase amplification | |
| CN203642941U (en) | Multipath sensing single-channel constant current measuring device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |