CN203069291U - Thermistor-based temperature detection circuit - Google Patents
Thermistor-based temperature detection circuit Download PDFInfo
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- CN203069291U CN203069291U CN 201320058682 CN201320058682U CN203069291U CN 203069291 U CN203069291 U CN 203069291U CN 201320058682 CN201320058682 CN 201320058682 CN 201320058682 U CN201320058682 U CN 201320058682U CN 203069291 U CN203069291 U CN 203069291U
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- thermistor
- resistance
- resistor
- operational amplifier
- capacitor
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Abstract
The utility model provides a thermistor-based temperature detection circuit and particularly relates to the field of temperature detection technology, which comprises a triode, a thermistor, a capacitor, an operational amplifier, a first resistor, a second resistor and a third resistor. The emitter of the triode is connected with a ground terminal. The collector of the triode is connected with one end of the thermistor and one end of the first resistor respectively. The other end of the thermistor is connected with a power supply. The other end of the first resistor is connected with the pin of the capacitor and the pin of the operational amplifier respectively. The other end of the capacitor is connected with the ground terminal. The pin of the operational amplifier is respectively connected with one end of the second resistor and one end of the third resistor. The other end of the third resistor is connected with the ground terminal. The other end of the second resistor is connected with the output end of the operational amplifier. The thermistor-based temperature detection circuit has the advantages of simple structure, higher detection precision and lower development cost. Due to the adoption of the thermistor-based temperature detection circuit, the detection method is enabled to be more convenient in operation.
Description
Technical field
The utility model relates to the temperature detection technical field, is specifically related to a kind of temperature sensing circuit based on thermistor.
Background technology
Thermistor in the IGBT module needs accurately to detect its resistance, determines the temperature of thermistor in the IGBT module by the mode of tabling look-up according to resistance.The accurate detection of thermistor can improve the reliability that IGBT uses, and avoids the IGBT module because excess temperature damages.
Thermistor testing circuit commonly used at present has 2 kinds:
First kind, directly adopt a constant voltage source U1 power supply by resistance R 1 and the thermistor R ξ dividing potential drop of a known resistance, by the electric U2 on the A/D detection thermistor.Then can be very accurate by formula R ξ=U2*R1/ (U1-U2) method, but A/D chip costliness adopts on the A/D chip cost and can't accept for the detection of a resistance.And the use of A/D chip is complicated, and development difficulty is big.
Second kind, adopt and detect the resistance that the R-C charging rate is determined resistance.Resistance R 11 and R12 determine the comparative voltage of comparer, are high level by the electric capacity charging of R ξ until the Uout upset.The Uout signal triggers the Q1 conducting simultaneously to be come to capacitor discharge.Uout becomes the pulse voltage waveform, and its frequency is the function of corresponding R ξ: Fout=R ξ.This detection mode cost is low, and exploitation is simple, if less but the appearance value of electric capacity is chosen, the higher resistance that is difficult to accurately detect R ξ of the frequency ratio of Uout then.If instead the appearance value of electric capacity is bigger, then its appearance value precision is low, and temperature is floated greatly.So the accuracy of detection of sort circuit is lower.
The utility model content
The purpose of this utility model provides a kind of temperature sensing circuit based on thermistor, and it is simple in structure, has the higher detection precision, and has lowered cost of development, makes detection method easier.
In order to solve the existing problem of background technology, the utility model is by the following technical solutions: it comprises triode Q1, thermistor R ξ, capacitor C, operational amplifier A, first resistance R 1, second resistance R 2, the 3rd resistance R 3, the emitter of described triode Q1 is connected with earth terminal, the collector of triode Q1 respectively with thermistor R ξ, one end of first resistance R 1 connects, the other end of thermistor R is connected with power supply, first resistance R, 1 other end respectively with capacitor C, the pin 1 of operational amplifier A connects, the other end of capacitor C is connected with earth terminal, operational amplifier A pin 2 respectively with second resistance R 2, one end of the 3rd resistance R 3 connects, the other end of the 3rd resistance R 3 is connected with earth terminal, and second resistance R, 2 other ends are connected with operational amplifier A output terminal 3.
The utility model principle of work: an end comparison reference voltage of this operational amplifier A is a stagnant loop voltag, the voltage that an other terminal voltage of comparer is capacitor charge and discharge.Discharging and recharging at Uout of electric capacity formed pulse waveform, and Uout is the trigger pip of Q1 simultaneously.R ξ is thermistor, and R1 is reference resistance.When Uout was high level, capacitor C was discharged by R1, and its discharge time, Ton was directly proportional with the product of R1*C.When Uout was low level, capacitor C was discharged by R1, and its discharge time, Toff was directly proportional with the product of (R1+ R ξ) * C.So Ton/Toff=R1/ (R1+R ξ) can accurately detect time of Ton and Toff by controller, R1 is that its precision of resistance is 1% to be resistance commonly used simultaneously.So the cost of development of this circuit is low, need not the expensive element of A/D and so on, and very high accuracy of detection is arranged.
The utlity model has following beneficial effect: it is simple in structure, has the higher detection precision, and has lowered cost of development, makes detection method easier.
Description of drawings
Fig. 1 is first kind of detection mode circuit diagram of the utility model background technology;
Fig. 2 is second kind of detection mode circuit diagram of the utility model background technology;
Fig. 3 the utility model detection mode circuit diagram.
Embodiment
Referring to Fig. 3, this embodiment is by the following technical solutions: it comprises triode Q1, thermistor R ξ, capacitor C, operational amplifier A, first resistance R 1, second resistance R 2, the 3rd resistance R 3, the emitter of described triode Q1 is connected with earth terminal, the collector of triode Q1 respectively with thermistor R ξ, one end of first resistance R 1 connects, the other end of thermistor R is connected with power supply, first resistance R, 1 other end respectively with capacitor C, the pin 1 of operational amplifier A connects, the other end of capacitor C is connected with earth terminal, operational amplifier A pin 2 respectively with second resistance R 2, one end of the 3rd resistance R 3 connects, the other end of the 3rd resistance R 3 is connected with earth terminal, and second resistance R, 2 other ends are connected with operational amplifier A output terminal 3.
The utility model principle of work: an end comparison reference voltage of this operational amplifier A is a stagnant loop voltag, the voltage that an other terminal voltage of comparer is capacitor charge and discharge.Discharging and recharging at Uout of electric capacity formed pulse waveform, and Uout is the trigger pip of Q1 simultaneously.R ξ is thermistor, and R1 is reference resistance.When Uout was high level, capacitor C was discharged by R1, and its discharge time, Ton was directly proportional with the product of R1*C.When Uout was low level, capacitor C was discharged by R1, and its discharge time, Toff was directly proportional with the product of R1+ R ξ * C.So Ton/Toff=R1/ (R1+R ξ) can accurately detect time of Ton and Toff by controller, R1 is that its precision of resistance is 1% to be resistance commonly used simultaneously.So the cost of development of this circuit is low, need not the expensive element of A/D and so on, and very high accuracy of detection is arranged.
The utlity model has following beneficial effect: it is simple in structure, has the higher detection precision, and has lowered cost of development, makes detection method easier.
Claims (1)
1. temperature sensing circuit based on thermistor, it is characterized in that it comprises triode (Q1), thermistor (R ξ), electric capacity (C), operational amplifier (A), first resistance (R1), second resistance (R2), the 3rd resistance (R3), the emitter of described triode (Q1) is connected with earth terminal, the collector of triode (Q1) respectively with thermistor (R ξ), one end of first resistance (R1) connects, the other end of thermistor (R) is connected with power supply, first resistance (R1) other end respectively with electric capacity (C), the pin (1) of operational amplifier (A) connects, the other end of electric capacity (C) is connected with earth terminal, operational amplifier (A) pin (2) respectively with second resistance (R2), one end of the 3rd resistance (R3) connects, the other end of the 3rd resistance (R3) is connected with earth terminal, and second resistance (R2) other end is connected with operational amplifier (A) output terminal (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320058682 CN203069291U (en) | 2013-02-02 | 2013-02-02 | Thermistor-based temperature detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320058682 CN203069291U (en) | 2013-02-02 | 2013-02-02 | Thermistor-based temperature detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203069291U true CN203069291U (en) | 2013-07-17 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320058682 Expired - Fee Related CN203069291U (en) | 2013-02-02 | 2013-02-02 | Thermistor-based temperature detection circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN203069291U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103148953A (en) * | 2013-02-02 | 2013-06-12 | 上海双电电气有限公司 | Temperature detecting circuit based on thermistor |
| CN107966641A (en) * | 2017-12-06 | 2018-04-27 | 珠海泰芯半导体有限公司 | A kind of IGBT life monitoring systems |
| CN110044510A (en) * | 2019-05-17 | 2019-07-23 | 上海希形科技有限公司 | IGBT module temperature measurement circuit, temp measuring method and computer readable storage medium |
-
2013
- 2013-02-02 CN CN 201320058682 patent/CN203069291U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103148953A (en) * | 2013-02-02 | 2013-06-12 | 上海双电电气有限公司 | Temperature detecting circuit based on thermistor |
| CN107966641A (en) * | 2017-12-06 | 2018-04-27 | 珠海泰芯半导体有限公司 | A kind of IGBT life monitoring systems |
| CN110044510A (en) * | 2019-05-17 | 2019-07-23 | 上海希形科技有限公司 | IGBT module temperature measurement circuit, temp measuring method and computer readable storage medium |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130717 Termination date: 20190202 |