CN207779584U - A kind of thermal resistance measuring device - Google Patents
A kind of thermal resistance measuring device Download PDFInfo
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- CN207779584U CN207779584U CN201820076252.6U CN201820076252U CN207779584U CN 207779584 U CN207779584 U CN 207779584U CN 201820076252 U CN201820076252 U CN 201820076252U CN 207779584 U CN207779584 U CN 207779584U
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- 230000005611 electricity Effects 0.000 claims description 4
- 238000012360 testing method Methods 0.000 abstract description 9
- 238000005259 measurement Methods 0.000 abstract description 5
- 238000010586 diagram Methods 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 2
- 238000010998 test method Methods 0.000 description 1
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Abstract
The utility model provides a kind of thermal resistance measuring device, which is characterized in that thermal resistance measuring device includes channel circuit, the first current source and the second current source, and the first current source and the second current source provide constant current for channel circuit；Channel circuit includes first resistor, thermal resistance, second resistance, 3rd resistor and the 4th resistance；The first end of first resistor is connect with the first end of the first current source, the second end of first current source is grounded, the second end of first resistor and the first end of thermal resistance connect, the second end of thermal resistance is connected with the first end of second resistance, the first end of 3rd resistor, the second end of second resistance is connect with the first end of the second current source, the second end of second current source is grounded, and the second end of 3rd resistor is connect with the first end of the 4th resistance, the second end ground connection of the 4th resistance.Thermal resistance measuring temperature is carried out by using three-wire system mode, opposite four-line measurement mode circuit is simple, and can also eliminate test error caused by p-wire.
Description
Technical field
The utility model is related to circuit field more particularly to a kind of thermal resistance measuring devices.
Background technology
In the prior art, mainly there are electric resistance partial pressure and current source two ways by thermal resistance measuring temperature.Electric resistance partial pressure
Mode be suitble to test compared with short-term road the case where, for the longer scene of p-wire and be not suitable for；The thermal resistance of current source mode
In measuring temperature, the modes such as point a variety of measurement methods, such as two-wire system, four-wire system.In two-wire system measurement method, survey can not be eliminated
The test error of line reference is tried, four-wire system can eliminate test error caused by p-wire, but the circuit of four-line measurement compares
It is complicated.
Utility model content
The utility model provides a kind of thermal resistance measuring device, and carrying out thermal resistance by using three-wire system mode measures temperature
Degree, opposite four-line measurement mode circuit is simple, and can also eliminate test error caused by p-wire.
The utility model embodiment provides a kind of thermal resistance measuring device, which may include：
A kind of thermal resistance measuring device, thermal resistance measuring device include channel circuit, the first current source and the second current source,
First current source and the second current source provide constant current for channel circuit；Channel circuit includes first resistor, thermal resistance, second
Resistance, 3rd resistor and the 4th resistance；The first end of first resistor is connect with the first end of the first current source, the first current source
Second end is grounded, and the first end of the second end of first resistor and thermal resistance connects, and the of the second end of thermal resistance and second resistance
One end, 3rd resistor first end be connected, the second end of second resistance is connect with the first end of the second current source, the second electric current
The second end in source is grounded, and the second end of 3rd resistor is connect with the first end of the 4th resistance, the second end ground connection of the 4th resistance.
In a mode in the cards, the current value of the first current source and the output of the second current source is identical.
In a mode in the cards, first resistor, second resistance are identical with the resistance value of 3rd resistor.
In a mode in the cards, the circuit of the first current source and the second current source is respectively voltage switching current
Circuit.
In a mode in the cards, voltage switching current circuit includes voltage follower, with mutually summation amplifier electricity
Road, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and the 9th resistance；
First input end with mutually summation operational amplifier circuit passes through the 5th resistance eutral grounding, the first end of the 6th resistance and the 5th electricity
The first end of resistance, the first input end connection with operational amplifier circuit of mutually summing, the second end of the 6th resistance and same mutually summation amplifier are electric
The output end on road connects, and connects the first end of the 7th resistance；With the second input terminal and the 8th resistance of operational amplifier circuit of mutually summing
First end, the connection of the first end of the 9th resistance, the second end of the 8th resistance connects power supply, the second end and voltage of the 9th resistance
The output end of follower connects, and the first input end of voltage follower is connect with the second end of the 7th resistance, voltage follower
Second input terminal is connect with the second end of the 9th resistance.
In a mode in the cards, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and the 9th resistance
Resistance value it is equal.
Based on thermal resistance measuring device provided by the utility model, by using the double constant-current source tests of three-wire system to thermal resistance
Thermoelectrical potential measure, further obtain measuring temperature.
Description of the drawings
Fig. 1 is a kind of circuit diagram for thermal resistance measuring device that the utility model embodiment provides；
Fig. 2 is a kind of voltage switching current circuit diagram provided by the utility model.
Specific implementation mode
The utility model embodiment provides a kind of thermal resistance measuring device, and thermal resistance measurement is carried out using three-wire system mode
Temperature, opposite four-line measurement mode circuit is simple, and can also eliminate test error caused by p-wire.
The technical solution of the utility model is described below in conjunction with the accompanying drawings.It should be noted that in the utility model
In " first ", " second ", " third ", " the 4th ", " the 5th ", " the 6th ", " the 7th ", " the 8th ", " the 9th " is used for the purpose of
Resistance is distinguished, resistance itself is not limited.
Fig. 1 is a kind of circuit diagram for thermal resistance measuring device that the utility model embodiment provides.As shown in Figure 1,
Thermal resistance measuring device includes a kind of thermal resistance measuring device, and thermal resistance measuring device includes channel circuit, the first current source I1
With the second current source I2, the first current source I1 and the second current source I2 constant current is provided for channel circuit；Channel circuit includes
First resistor RLEAD, thermal resistance RRTD, second resistance RLEAD, 3rd resistor RLEADWith the 4th resistance RREF；First resistor RLEAD
One end is connect with the first end of the first current source, the second end ground connection of the first current source, first resistor RLEADSecond end with heat
Resistance RRTDFirst end connection, thermal resistance RRTDSecond end and second resistance RLEADFirst end, 3rd resistor RLEADFirst
End is connected, second resistance RLEADSecond end connect with the first end of the second current source, the second end of the second current source ground connection,
3rd resistor RLEADSecond end and the 4th resistance RREFFirst end connection, the 4th resistance RREFSecond end ground connection.
In the present invention, the first current source and the current value of the second current source output are identical.
In the present invention, first resistor RLEAD, second resistance RLEADWith 3rd resistor RLEADResistance value it is identical.
In the present invention, the circuit of the first current source and the second current source is respectively voltage switching current circuit.
As shown in Figure 1, the output current of two constant-current sources used in test is identical, then：I1=I2=I
The double constant-current source method of testing RTD input voltages of three-wire system：
VDIFF=VIN+-VIN-；
VDIFF=(I × (RLEAD+RRTD)+2×I×(RLEAD+RREF))-(I×RLEAD+2×I×(RLEAD+RREF))；
VDIFF=I × RRTD；
The DC resistance that p-wire can be obtained by above formula is completely eliminated.
Testing the output current value of two constant-current sources used must be identical, at the same when PCB layout constant-current source to pedestal
PCB trace impedance, the contact impedance of connector and pedestal connecting terminal are necessary equal to the sum of the cable resistance of thermal resistance.
In the present invention, voltage switching current circuit includes voltage follower U1-1, with mutually summation operational amplifier circuit U2-
1, the 5th resistance (R4), the 6th resistance (R5), the 7th resistance (R1), the 8th resistance (R3) and the 9th resistance (R2)；
First input end with mutually summation operational amplifier circuit U2-1 is grounded by the 5th resistance (R4), and the of the 6th resistance (R5)
One end and the first end of the 5th resistance (R4) are connect with the first input end of mutually summation operational amplifier circuit, and the of the 6th resistance (R5)
Two ends are connect with the output end with mutually summation operational amplifier circuit, and connect the first end of the 7th resistance (R1)；With mutually summation amplifier electricity
The second input terminal of road U2-1 is connect with the first end of the 8th resistance (R3), the first end of the 9th resistance (R2), the 8th resistance
(R3) second end connects power supply, and the second end of the 9th resistance (R2) is connect with the output end of voltage follower U1-1, voltage with
It is connect with the second end of the 7th resistance (R1) with the first input end of device U1-1, the second input terminal of voltage follower U1-1 and
The second end of nine resistance (R2) connects.Wherein, the 5th resistance (R4), the 6th resistance (R5), the 7th resistance (R1), the 8th resistance
(R3) and the resistance value of the 9th resistance (R2) is equal.
As shown in Fig. 2, circuit theory is analyzed as follows：
UD=UB
UA=2UC=UB+UE
So far, although those skilled in the art will appreciate that the more of the utility model have been shown and described in detail herein
A exemplary embodiment still, still can be according to the utility model public affairs in the case where not departing from the spirit and scope of the utility model
The content opened directly determines or derives many other variations or modifications consistent with the principles of the invention.Therefore, the utility model
Range is understood that and regards as to cover other all these variations or modifications.
Claims (6)
1. a kind of thermal resistance measuring device, which is characterized in that the thermal resistance measuring device includes channel circuit, the first current source
With the second current source, first current source and second current source provide constant current for the channel circuit；It is described logical
Road circuit includes first resistor, thermal resistance, second resistance, 3rd resistor and the 4th resistance；The first end of the first resistor with
The first end of first current source connects, the second end ground connection of first current source, the second end of the first resistor with
The first end of the thermal resistance connects, first end, the 3rd resistor of the second end of the thermal resistance and the second resistance
First end be connected, the second end of the second resistance is connect with the first end of second current source, second electric current
The second end in source is grounded, and the second end of the 3rd resistor is connect with the first end of the 4th resistance, the 4th resistance
Second end is grounded.
2. the apparatus according to claim 1, which is characterized in that first current source and second current source output
Current value is identical.
3. device according to claim 1 or 2, which is characterized in that the first resistor, the second resistance and described
The resistance value of three resistance is identical.
4. device according to claim 3, which is characterized in that the circuit of first current source and second current source
Respectively voltage switching current circuit.
5. device according to claim 4, which is characterized in that the voltage switching current circuit include voltage follower,
With mutually summation operational amplifier circuit, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and the 9th resistance；
The first input end with mutually summation operational amplifier circuit passes through the 5th resistance eutral grounding, the first end of the 6th resistance
It is connect with the first end of the 5th resistance, the first input end with mutually summation operational amplifier circuit, the of the 6th resistance
Two ends are connect with the output end with mutually summation operational amplifier circuit, and connect the first end of the 7th resistance；It is described mutually to ask together
It is connect with the second input terminal of operational amplifier circuit with the first end of the 8th resistance, the first end of the 9th resistance, described
The second end of eight resistance connects power supply, and the second end of the 9th resistance is connect with the output end of the voltage follower, described
The first input end of voltage follower is connect with the second end of the 7th resistance, the second input terminal of the voltage follower with
The second end of 9th resistance connects.
6. device according to claim 5, which is characterized in that the 5th resistance, the 6th resistance, the 7th electricity
The resistance value of resistance, the 8th resistance and the 9th resistance is equal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820076252.6U CN207779584U (en) | 2018-01-17 | 2018-01-17 | A kind of thermal resistance measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820076252.6U CN207779584U (en) | 2018-01-17 | 2018-01-17 | A kind of thermal resistance measuring device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207779584U true CN207779584U (en) | 2018-08-28 |
Family
ID=63213107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820076252.6U Active CN207779584U (en) | 2018-01-17 | 2018-01-17 | A kind of thermal resistance measuring device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207779584U (en) |
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2018
- 2018-01-17 CN CN201820076252.6U patent/CN207779584U/en active Active
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