CN204065041U - The permanent source and course circuit of thermal conductivity detector (TCD) - Google Patents
The permanent source and course circuit of thermal conductivity detector (TCD) Download PDFInfo
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- CN204065041U CN204065041U CN201420172419.0U CN201420172419U CN204065041U CN 204065041 U CN204065041 U CN 204065041U CN 201420172419 U CN201420172419 U CN 201420172419U CN 204065041 U CN204065041 U CN 204065041U
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- 230000008878 coupling Effects 0.000 claims abstract description 20
- 238000010168 coupling process Methods 0.000 claims abstract description 20
- 238000005859 coupling reaction Methods 0.000 claims abstract description 20
- 230000003287 optical effect Effects 0.000 claims abstract description 20
- 230000005669 field effect Effects 0.000 claims abstract description 12
- 230000003321 amplification Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000006641 stabilisation Effects 0.000 description 2
- 238000011105 stabilization Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000005272 metallurgy Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000004451 qualitative analysis Methods 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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Abstract
The utility model discloses the permanent source and course circuit of a kind of thermal conductivity detector (TCD), it relates to thermal conductivity detector (TCD) technical field.1 pin of its linear optical coupling respectively with the grid of field effect transistor, one end of 9th resistance is connected, 2 pin of linear optical coupling respectively with the 8th resistance one end, 6 pin of the second amplifier are connected, 8th resistance other end ground connection, 3 pin of linear optical coupling connect 7 pin of the 7th resistance to the second amplifier, 5 pin of the second amplifier connect 1 pin of the first amplifier, 3 pin of the first amplifier are connected with potentiometer, 2 pin of the first amplifier are connected with the 6th resistance one end, the 6th resistance other end respectively with the 5th resistance one end, 4th resistance one end, 3rd resistance one end is connected, 5th resistance other end ground connection, first resistance of series connection and the 4th resistance and second resistance of connecting and the 3rd resistor coupled in parallel.The utility model structure is simple, reliable, does not have current fluctuation, easy to use and reliable.
Description
Technical field
The utility model relates to thermal conductivity detector (TCD) technical field, be specifically related to the permanent source and course circuit of a kind of thermal conductivity detector (TCD).
Background technology
Along with the develop rapidly in the fields such as oil, chemical industry, metallurgy, biology, the requirement thus carrying out qualitative and quantitative analysis to material composition becomes more strict, more needs that speed is fast, highly sensitive, the analytical approach of applied range and instrument.Gas chromatograph has been put as the representative of day analytical instrumentation fields such as being widely used in biology, medical science, chemistry.Thermal conductivity detector (TCD) (TCD) utilizes tested component different with the coefficient of heat conductivity of carrier gas and the concentration detector of response.
The bridge current circuit of traditional thermal conductivity detector (TCD), when bridge stream is larger, the grid voltage of field effect transistor reaches 20 more and lies prostrate, and has exceeded field effect transistor supply voltage scope (18V), has therefore easily broken down.
Utility model content
For the deficiency that prior art exists, the utility model object is to provide a kind of thermal conductivity detector (TCD) permanent source and course circuit, and structure is simple, reliable, does not have current fluctuation, easy to use and reliable.
To achieve these goals, the utility model realizes by the following technical solutions: the permanent source and course circuit of thermal conductivity detector (TCD), comprise the first amplifier, second amplifier, linear optical coupling, first resistance-nine resistance, potentiometer and field effect transistor, 1 pin of linear optical coupling respectively with the grid of field effect transistor, one end of 9th resistance is connected, 2 pin of linear optical coupling respectively with the 8th resistance one end, 6 pin of the second amplifier are connected, 8th resistance other end ground connection, 3 pin of linear optical coupling connect 7 pin of the 7th resistance to the second amplifier, 5 pin of the second amplifier connect 1 pin of the first amplifier, 3 pin of the first amplifier are connected with potentiometer, 2 pin of the first amplifier are connected with the 6th resistance one end, the 6th resistance other end respectively with the 5th resistance one end, 4th resistance one end, 3rd resistance one end is connected, 5th resistance other end ground connection, first resistance of series connection and the 4th resistance and second resistance of connecting and the 3rd resistor coupled in parallel, first resistance and the second resistance connected node and the 9th resistance other end, the source electrode of field effect transistor is connected.
The first described amplifier, the second amplifier all adopt AD8662.
Described linear optical coupling adopts HCNR201.
The utility model structure is simple, reliable, does not have current fluctuation, easy to use and reliable.
Accompanying drawing explanation
The utility model is described in detail below in conjunction with the drawings and specific embodiments;
Fig. 1 is circuit diagram of the present utility model.
Embodiment
The technological means realized for making the utility model, creation characteristic, reaching object and effect is easy to understand, below in conjunction with embodiment, setting forth the utility model further.
With reference to Fig. 1, this embodiment is by the following technical solutions: the permanent source and course circuit of thermal conductivity detector (TCD), comprise the first amplifier U1A, second amplifier U1B, linear optical coupling U2, first resistance R1-the 9th resistance R9, potentiometer RW and field effect transistor IRF640, 1 pin of linear optical coupling U2 respectively with the grid of field effect transistor IRF640, one end of 9th resistance R9 is connected, 2 pin of linear optical coupling U2 respectively with the 8th resistance R8 one end, 6 pin of the second amplifier U1B are connected, 8th resistance R8 other end ground connection, 3 pin of linear optical coupling U2 connect 7 pin of the 7th resistance R7 to the second amplifier U1B, 5 pin of the second amplifier U1B connect 1 pin of the first amplifier U1A, 3 pin of the first amplifier U1A are connected with potentiometer RW, 2 pin of the first amplifier U1A are connected with the 6th resistance R6 one end, the 6th resistance R6 other end respectively with the 5th resistance R5 one end, 4th resistance R4 one end, 3rd resistance R3 one end is connected, 5th resistance R5 other end ground connection, first resistance R1 of series connection and the 4th resistance R4 is in parallel with the second resistance R2 connected and the 3rd resistance R3, first resistance R1 and the second resistance R2 connected node and the 9th resistance R9 other end, the source electrode of field effect transistor IRF640 is connected.
It should be noted that the first described amplifier U1A, the second amplifier U1B all adopts AD8662.
In addition, described linear optical coupling U2 adopts HCNR201.
The output signal M of this embodiment, N, namely by measuring the potential difference (PD) between M, N at 2, just can measure composition and the content of material.5th resistance R5 is sampling resistor, resistance is 10 Ω, when upper current limit is 250mA, employing voltage is 2.5V, adopts voltage to be input to 2 pin of the first amplifier U1A, and that 3 pin of the first amplifier U1A connect is a potentiometer RW, one end ground connection of potentiometer RW, another termination+2.5V voltage reference, is exported by voltage stabilizing chip ADR431 during this+2.5V, temperature stabilization 1ppm/ DEG C.After the voltage of the potentiometer set, when 2 pin of AD8662,3 pin voltages are unequal, its differential pressure is amplified through amplifier AD8662 open loop, drive 5 pin of AD8662, the second amplifier U1B and linear optical coupling U2 forms the amplifying circuit of light-coupled isolation, and amplification ratio is 500K/75K=6.7 times.AD8662 and linear optical coupling U2 forms the differential pressure amplifying circuit of amplification ratio 1.47*106, and play current stabilization effect, when bridge stream voltage has the fluctuation of 0.1uA, the change in voltage being applied to IRF640 grid reaches 1.47V, IRF640 increased or reduces electric current, thus eliminating current fluctuation.
This embodiment structure is simple, reliable, does not have current fluctuation, easy to use and reliable.
More than show and describe ultimate principle of the present utility model and principal character and advantage of the present utility model.The technician of the industry should understand; the utility model is not restricted to the described embodiments; what describe in above-described embodiment and instructions just illustrates principle of the present utility model; under the prerequisite not departing from the utility model spirit and scope; the utility model also has various changes and modifications, and these changes and improvements all fall within the scope of claimed the utility model.The claimed scope of the utility model is defined by appending claims and equivalent thereof.
Claims (3)
1. the permanent source and course circuit of thermal conductivity detector (TCD), it is characterized in that, comprise the first amplifier (U1A), second amplifier (U1B), linear optical coupling (U2), first resistance (R1)-nine resistance (R9), potentiometer (RW) and field effect transistor (IRF640), 1 pin of linear optical coupling (U2) respectively with the grid of field effect transistor (IRF640), one end of 9th resistance (R9) is connected, 2 pin of linear optical coupling (U2) respectively with the 8th resistance (R8) one end, 6 pin of the second amplifier (U1B) are connected, 8th resistance (R8) other end ground connection, 3 pin of linear optical coupling (U2) connect 7 pin of the 7th resistance (R7) to the second amplifier (U1B), 5 pin of the second amplifier (U1B) connect 1 pin of the first amplifier (U1A), 3 pin of the first amplifier (U1A) are connected with potentiometer RW, 2 pin of the first amplifier (U1A) are connected with the 6th resistance (R6) one end, 6th resistance (R6) other end respectively with the 5th resistance (R5) one end, 4th resistance (R4) one end, 3rd resistance (R3) one end is connected, 5th resistance (R5) other end ground connection, first resistance (R1) of connecting and the 4th resistance (R4) and second resistance (R2) of connecting and the 3rd resistance (R3) parallel connection, first resistance (R1) and the second resistance (R2) connected node and the 9th resistance (R9) other end, the source electrode of field effect transistor (IRF640) is connected.
2. the permanent source and course circuit of thermal conductivity detector (TCD) according to claim 1, it is characterized in that, described the first amplifier (U1A), the second amplifier (U1B) all adopt AD8662.
3. the permanent source and course circuit of thermal conductivity detector (TCD) according to claim 1, it is characterized in that, described linear optical coupling (U2) adopts HCNR201.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420172419.0U CN204065041U (en) | 2014-04-10 | 2014-04-10 | The permanent source and course circuit of thermal conductivity detector (TCD) |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420172419.0U CN204065041U (en) | 2014-04-10 | 2014-04-10 | The permanent source and course circuit of thermal conductivity detector (TCD) |
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| Publication Number | Publication Date |
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| CN204065041U true CN204065041U (en) | 2014-12-31 |
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| CN201420172419.0U Expired - Fee Related CN204065041U (en) | 2014-04-10 | 2014-04-10 | The permanent source and course circuit of thermal conductivity detector (TCD) |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106153790A (en) * | 2015-05-11 | 2016-11-23 | 西门子公司 | Thermal conductivity detector (TCD) and the method being used for operating thermal conductivity detector (TCD) |
-
2014
- 2014-04-10 CN CN201420172419.0U patent/CN204065041U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106153790A (en) * | 2015-05-11 | 2016-11-23 | 西门子公司 | Thermal conductivity detector (TCD) and the method being used for operating thermal conductivity detector (TCD) |
| CN106153790B (en) * | 2015-05-11 | 2018-02-23 | 西门子公司 | Thermal conductivity detector (TCD) and the method for operating thermal conductivity detector (TCD) |
| US10126277B2 (en) | 2015-05-11 | 2018-11-13 | Siemens Aktiengesellschaft | Method and thermal conductivity detector |
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| 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: 20141231 |
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| CF01 | Termination of patent right due to non-payment of annual fee |