CN202329876U - Thermocouple disconnection detection circuit - Google Patents
Thermocouple disconnection detection circuit Download PDFInfo
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- CN202329876U CN202329876U CN2011203438221U CN201120343822U CN202329876U CN 202329876 U CN202329876 U CN 202329876U CN 2011203438221 U CN2011203438221 U CN 2011203438221U CN 201120343822 U CN201120343822 U CN 201120343822U CN 202329876 U CN202329876 U CN 202329876U
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- thermopair
- resistance
- thermocouple
- detection circuit
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Abstract
The utility model discloses a thermocouple disconnection detection circuit, which comprises an operational amplifier and a thermocouple, wherein a negative input end of the operational amplifier is connected to a second reference voltage input end; a positive input end of the operational amplifier is connected to the thermocouple through a first resistor; an output end of the operational amplifier is used for outputting a detection signal; one end of the thermocouple is connected to a first reference voltage input end through a second resistor; and the other end of the thermocouple is connected to a zero point voltage input end through a third resistor; simultaneously, two ends of the third resistor are respectively connected to the zero point voltage input end and the first resistor. By means of the thermocouple disconnection detection circuit, dependence of disconnection inspection on an ADC (Analogue to Digital Converter) is saved; the disconnection inspection can be carried out at any time and can also be carried out with acquisition and conversion of the ADC in parallel, so that temperature acquisition of the ADC is not influenced; furthermore, the judgement time of the thermocouple disconnection detection circuit on thermocouple disconnection inspection is in microsecond grade, so that time required for the disconnection inspection is greatly saved, and conversion and acquisition efficiency of the ADC can be increased.
Description
Technical field
The utility model relates to circuit field, particularly a kind of thermopair break detection circuit.
Background technology
Thermopair is a temperature element commonly used in the temperature measuring instrument.When the conductor two ends by two kinds of heterogeneities are bonded into the loop, different like two abutment electric thermo-couple temperatures, will in the loop, produce thermocurrent.When if the working end of thermopair and reference edge have the temperature difference, Displaying Meter will indicate the pairing temperature value of thermoelectrical potential that thermopair produces.The profile of various thermopairs is often far from it because of needs, but their basic structure is roughly the same, is made up of major parts such as thermode, insulation sleeve protection tube and terminal boxes usually, the common and supporting use of Displaying Meter, recorder and electronic controller.
In order to guarantee the operate as normal of thermopair, need carry out electric circuit inspection to thermopair.Existing thermopair testing circuit is as shown in Figure 1.It comprises: ADC (analog to digital converter), injecting voltage, switch 1, resistance M1, resistance M2, resistance M3, resistance M4 and reference voltage.In the time will carrying out continuity test, at first switch 1 is in closure state, this moment, injecting voltage flowed into thermopair through switch 1, resistance M1, and flowed into reference voltage terminal from resistance M4.If the hypothesis injecting voltage is V1, reference voltage is V2, and V1>V2.Its principle of work is following: when thermocouple sensor was in the broken string state, injecting voltage injected this loop, and resistance M2 and the relative voltage between the resistance M3 that ADC gathers are V1-V2.Relative voltage between resistance M2 and the resistance M3 is gathered and judged through ADC, can realize the thermopair continuity test.
Yet, because foregoing circuit need use extra voltage signal to be injected on the thermocouple sensor, and use the ADC of thermocouple voltages signals collecting that the voltage that is injected into thermocouple sensor is gathered, judge with this whether thermocouple sensor breaks.The method be owing to will rely on ADC and carry out continuity test, and it is all very low to do the ADC slewing rate that thermopair gathers usually, and gathering primary voltage usually needs the time more than 50 milliseconds, therefore, has greatly reduced the efficient of thermopair Acquisition Circuit.
Therefore, also there is certain deficiency in prior art.
The utility model content
In view of the weak point of above-mentioned prior art, the purpose of the utility model is to provide a kind of fast thermocouple break detection circuit, to solve thermopair break detection circuit slow, inefficient problem detection time of prior art.
In order to achieve the above object, the utility model has been taked following technical scheme:
A kind of thermopair break detection circuit is used for thermopair is carried out burn out detection, and wherein, said circuit comprises:
One operational amplifier, its negative input end connects second reference voltage input, and positive input terminal connects thermopair through first resistance, and output terminal is used for output detection signal;
Thermopair; The one of which end connects first reference voltage input through second resistance, and the other end connects the zero-point voltage input end through the 3rd resistance;
The two ends of said the 3rd resistance connect the zero-point voltage input end and first resistance respectively.
Described thermopair break detection circuit, wherein, said first reference voltage is greater than second reference voltage.
Described thermopair break detection circuit, wherein, said second reference voltage is greater than zero-point voltage.
Described thermopair break detection circuit, wherein, the two ends of said thermopair link to each other with analog to digital converter with the 5th resistance through the 4th resistance respectively.
The thermopair break detection circuit that the utility model provides; It comprises: operational amplifier and thermopair; The negative input end of said operational amplifier connects second reference voltage input, and positive input terminal connects thermopair through first resistance, and output terminal is used for output detection signal.One end of said thermopair connects first reference voltage input through second resistance, and the other end connects the zero-point voltage input end through the 3rd resistance, and simultaneously, the two ends of said the 3rd resistance connect the zero-point voltage input end and first resistance respectively.Saved the dependence of continuity test to ADC through this circuit: continuity test can carry out at any time, and can gather and change parallel carrying out with ADC, does not influence the collection of ADC to temperature.In addition, this circuit is the microsecond rank to the judgement time of thermopair continuity test, needs 50 milliseconds of left and right sides times to compare with ADC to the thermopair judgement, has saved the needed time of continuity test greatly, has improved conversion and the collecting efficiency of ADC.
Description of drawings
Fig. 1 is the circuit theory diagrams of the thermopair testing circuit of prior art.
Fig. 2 is the circuit theory diagrams of the thermopair break detection circuit of the utility model.
Embodiment
The utility model provides a kind of thermopair break detection circuit.For the purpose, technical scheme and the effect that make the utility model is clearer, clear and definite, below with reference to accompanying drawing and give an actual example to the utility model further explain.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
See also Fig. 2, Fig. 2 is the circuit theory diagrams of the thermopair break detection circuit of the utility model.As shown in the figure; Said thermopair break detection circuit (being break detection circuit in the frame of broken lines) comprising: operational amplifier 10 and thermopair 20; The negative input end of said operational amplifier 10 connects second reference voltage input; Positive input terminal connects thermopair 20 through first resistance R 1, and output terminal 110 is used for output detection signal.One end of said thermopair 20 connects first reference voltage input through second resistance R 2, and the other end connects the zero-point voltage input end through the 3rd resistance R 3, and simultaneously, the two ends of said the 3rd resistance R 3 connect the zero-point voltage input end and first resistance R 1 respectively.
Introduce its circuit theory below:
Particularly, in the thermopair break detection circuit of the utility model, said second reference voltage is greater than zero-point voltage, and in addition, said first reference voltage is greater than second reference voltage.When thermopair 20 does not break; First resistance R, 1 terminal voltage and second resistance R, 2 terminal voltages are approaching, all be near the numerical value of first reference voltage, and second reference voltage are less than first reference voltage; This moment, first reference voltage connected the positive input terminal that gets into operational amplifier 10; And second reference voltage is input as the negative input end of operational amplifier 10, and then the broken string feedback signal of operational amplifier 10 is output as high level, i.e. output terminal output high level.In like manner; When thermopair 20 was in broken string, first resistance R, 1 terminal voltage and zero-point voltage were approaching, and second reference voltage of the negative input end of operational amplifier 10 input is higher than zero-point voltage; So the time operational amplifier broken string feedback signal output will be low level, i.e. output terminal output low level.So whether the level signal of the output terminal that we just can be through operational amplifier 10 is judged thermopair and is broken.
Further, the two ends of said thermopair 20 link to each other with analog to digital converter ADC with the 5th resistance R 5 through the 4th resistance R 4 respectively.Continuity test can carry out at any time, and can gather and change parallel carrying out with ADC, does not influence the collection of ADC to temperature.In addition, this circuit is the microsecond rank to the judgement time of thermopair continuity test, needs 50 milliseconds of left and right sides times to compare with ADC to the thermopair judgement, has saved the needed time of continuity test greatly, has improved conversion and the collecting efficiency of ADC.
In sum; The thermopair break detection circuit that the utility model provides, it comprises: operational amplifier and thermopair, the negative input end of said operational amplifier connects second reference voltage input; Positive input terminal connects thermopair through first resistance, and output terminal is used for output detection signal.One end of said thermopair connects first reference voltage input through second resistance, and the other end connects the zero-point voltage input end through the 3rd resistance, and simultaneously, the two ends of said the 3rd resistance connect the zero-point voltage input end and first resistance respectively.Owing to adopted the mode of operational amplifier; Saved dependence, only need differentiate, and need not use ADC that voltage is changed and gathered single voltage threshold to ADC and outside injecting voltage; And the differentiation time of voltage comparator is delicate rank; Far gather the time (the ADC slewing rate of doing the thermopair collection usually is all very low, and gathering primary voltage usually needs more than 50 milliseconds) of primary voltage, have good marketing property faster than the ADC that does the thermopair collection usually.
It is understandable that; Concerning those of ordinary skills; Can be equal to replacement or change according to the technical scheme and the utility model design thereof of the utility model, and all these changes or replacement all should belong to the protection domain of the appended claim of the utility model.
Claims (4)
1. a thermopair break detection circuit is used for thermopair is carried out burn out detection, it is characterized in that said circuit comprises:
One operational amplifier, its negative input end connects second reference voltage input, and positive input terminal connects thermopair through first resistance, and output terminal is used for output detection signal;
Thermopair; The one of which end connects first reference voltage input through second resistance, and the other end connects the zero-point voltage input end through the 3rd resistance;
The two ends of said the 3rd resistance connect the zero-point voltage input end and first resistance respectively.
2. thermopair break detection circuit according to claim 1 is characterized in that: said first reference voltage is greater than second reference voltage.
3. thermopair break detection circuit according to claim 1 is characterized in that: said second reference voltage is greater than zero-point voltage.
4. thermopair break detection circuit according to claim 1 is characterized in that: the two ends of said thermopair link to each other with analog to digital converter with the 5th resistance through the 4th resistance respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203438221U CN202329876U (en) | 2011-09-14 | 2011-09-14 | Thermocouple disconnection detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203438221U CN202329876U (en) | 2011-09-14 | 2011-09-14 | Thermocouple disconnection detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202329876U true CN202329876U (en) | 2012-07-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011203438221U Expired - Fee Related CN202329876U (en) | 2011-09-14 | 2011-09-14 | Thermocouple disconnection detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202329876U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103675596A (en) * | 2013-12-17 | 2014-03-26 | 重庆川仪自动化股份有限公司 | Wire breakage detection circuit and temperature acquisition circuit |
| CN103837793A (en) * | 2014-01-23 | 2014-06-04 | 冶金自动化研究设计院 | Instrument and method for rapidly detecting polarity of temperature-measuring thermal coupler |
| CN105339769A (en) * | 2013-06-28 | 2016-02-17 | Pr电子股份公司 | System and method for detection of wire breakage |
| CN112033580A (en) * | 2020-08-26 | 2020-12-04 | 广东高标电子科技有限公司 | Temperature sensing unit disconnection detection system, disconnection detection method and electric vehicle |
-
2011
- 2011-09-14 CN CN2011203438221U patent/CN202329876U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105339769A (en) * | 2013-06-28 | 2016-02-17 | Pr电子股份公司 | System and method for detection of wire breakage |
| CN103675596A (en) * | 2013-12-17 | 2014-03-26 | 重庆川仪自动化股份有限公司 | Wire breakage detection circuit and temperature acquisition circuit |
| CN103675596B (en) * | 2013-12-17 | 2016-05-25 | 重庆川仪自动化股份有限公司 | A kind of break detection circuit and temperature collection circuit |
| CN103837793A (en) * | 2014-01-23 | 2014-06-04 | 冶金自动化研究设计院 | Instrument and method for rapidly detecting polarity of temperature-measuring thermal coupler |
| CN103837793B (en) * | 2014-01-23 | 2017-02-15 | 冶金自动化研究设计院 | Instrument and method for rapidly detecting polarity of temperature-measuring thermal coupler |
| CN112033580A (en) * | 2020-08-26 | 2020-12-04 | 广东高标电子科技有限公司 | Temperature sensing unit disconnection detection system, disconnection detection method and electric vehicle |
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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 |
Granted publication date: 20120711 Termination date: 20160914 |
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| CF01 | Termination of patent right due to non-payment of annual fee |