TWI571631B - Gas sensor - Google Patents
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- TWI571631B TWI571631B TW105119664A TW105119664A TWI571631B TW I571631 B TWI571631 B TW I571631B TW 105119664 A TW105119664 A TW 105119664A TW 105119664 A TW105119664 A TW 105119664A TW I571631 B TWI571631 B TW I571631B
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Description
本發明是有關於一種感測器，且特別是有關於一種氣體感測器。This invention relates to a sensor and, more particularly, to a gas sensor.
化工產業的興起以及內燃機（即馬達）的大量使用，造成日益嚴重的環境污染，其中空氣污染的迫害對人類日常生活影響最為直接。因此，在空氣汙染源逐漸增加的現在，透過氣體感測器隨時隨地偵測環境的異常狀態已是一種趨勢。因此，如何提高氣體感測器的準確度則成為一個重要的課題。The rise of the chemical industry and the extensive use of internal combustion engines (ie, motors) have caused increasingly serious environmental pollution, and the persecution of air pollution has the most direct impact on human daily life. Therefore, it is a trend to detect the abnormal state of the environment anytime and anywhere through a gas sensor while the air pollution source is gradually increasing. Therefore, how to improve the accuracy of the gas sensor becomes an important issue.
本發明提供一種氣體感測器，可提高氣體濃度的感測靈敏度。The present invention provides a gas sensor that can improve the sensing sensitivity of a gas concentration.
本發明的氣體感測器，包括一第一感測元件、一第二感測元件及一電壓增強電路。第一感測元件耦接於一第一電壓與一第一節點之間，其中第一感測元件的阻抗值正比於氣體濃度。第二感測元件耦接於一第二電壓與第一節點之間，其中第二感測元件的阻抗值反比於氣體濃度。電壓增強電路耦接第一節點以接收第一節點提供的一節點電壓，並且對應地提供一氣體感測電壓。The gas sensor of the present invention comprises a first sensing element, a second sensing element and a voltage enhancement circuit. The first sensing element is coupled between a first voltage and a first node, wherein the impedance value of the first sensing element is proportional to the gas concentration. The second sensing element is coupled between a second voltage and the first node, wherein the impedance value of the second sensing element is inversely proportional to the gas concentration. The voltage enhancement circuit is coupled to the first node to receive a node voltage provided by the first node, and correspondingly provides a gas sensing voltage.
基於上述，本發明實施例的氣體感測器，其透過串接的正負電阻系數的第一感測元件及第二感測元件，依據氣體濃度推挽第一節點的節點電壓，因此可相對於氣體濃度加大節點電壓的變化幅度，亦即可提高氣體濃度的感測靈敏度。Based on the above, the gas sensor of the embodiment of the present invention transmits the node voltage of the first node according to the gas concentration through the first sensing element and the second sensing element of the positive and negative resistivity of the series connection, so The gas concentration increases the magnitude of the change in the node voltage, which also increases the sensing sensitivity of the gas concentration.
為讓本發明的上述特徵和優點能更明顯易懂，下文特舉實施例，並配合所附圖式作詳細說明如下。The above described features and advantages of the invention will be apparent from the following description.
圖1為依據本發明一實施例的氣體感測器的電路示意圖。請參照圖1，在本實施例中，氣體感測器100包括第一感測元件110、第二感測元件120及電壓增強電路130。第一感測元件110耦接於第一電壓V1與第一節點N1之間，其中第一感測元件110的阻抗值正比於空氣中待測氣體的氣體濃度。亦即，待測氣體的氣體濃度越低，第一感測元件110的阻抗值越低；待測氣體的氣體濃度越高，第一感測元件110的阻抗值越高，其中待測氣體可透過氣體分離系統加以過濾，或者第一感測元件110選用特定材料，此可依據本領域知識者而定，本發明實施例不以此為限。1 is a circuit diagram of a gas sensor in accordance with an embodiment of the present invention. Referring to FIG. 1 , in the embodiment, the gas sensor 100 includes a first sensing component 110 , a second sensing component 120 , and a voltage enhancement circuit 130 . The first sensing element 110 is coupled between the first voltage V1 and the first node N1, wherein the impedance value of the first sensing element 110 is proportional to the gas concentration of the gas to be tested in the air. That is, the lower the gas concentration of the gas to be tested, the lower the impedance value of the first sensing element 110; the higher the gas concentration of the gas to be tested, the higher the impedance value of the first sensing element 110, wherein the gas to be tested may be The embodiment of the present invention is not limited thereto. The first sensing element 110 is selected by a gas separation system, or the first sensing element 110 is selected from a specific material.
第二感測元件120耦接於第二電壓V2與第一節點N1之間，其中第二感測元件120的阻抗值反比於空氣中待測氣體的氣體濃度。亦即，待測氣體的氣體濃度越低，第一感測元件110的阻抗值越高，待測氣體的氣體濃度越高，第一感測元件110的阻抗值越低。The second sensing component 120 is coupled between the second voltage V2 and the first node N1, wherein the impedance value of the second sensing component 120 is inversely proportional to the gas concentration of the gas to be tested in the air. That is, the lower the gas concentration of the gas to be tested, the higher the impedance value of the first sensing element 110, and the higher the gas concentration of the gas to be tested, the lower the impedance value of the first sensing element 110.
電壓增強電路130耦接第一節點N1以接收第一節點N1提供的節點電壓Vn，並且對應地提供氣體感測電壓VGS，其中氣體感測電壓VGS相關於節點電壓Vn。例如，氣體感測電壓VGS等於節點電壓Vn，氣體感測電壓VGS等於X倍的節點電壓Vn，氣體感測電壓VGS正比於節點電壓Vn，或者，氣體感測電壓VGS反比於節點電壓Vn。上述為舉例以說明，本發明實施例不以此為限。The voltage boosting circuit 130 is coupled to the first node N1 to receive the node voltage Vn provided by the first node N1, and correspondingly provides a gas sensing voltage VGS, wherein the gas sensing voltage VGS is related to the node voltage Vn. For example, the gas sensing voltage VGS is equal to the node voltage Vn, the gas sensing voltage VGS is equal to X times the node voltage Vn, the gas sensing voltage VGS is proportional to the node voltage Vn, or the gas sensing voltage VGS is inversely proportional to the node voltage Vn. The foregoing is an example to illustrate that the embodiment of the present invention is not limited thereto.
在本實施例中，第一電壓V1是不同於第二電壓V2，例如第一電壓V1及第二電壓V2可分別為系統電壓及接地電壓。並且，本領域通常知識者可選擇第一電壓V1大於第二電壓V2，或者第二電壓V2大於第一電壓V1。當第一電壓V1大於第二電壓V2，則節點電壓Vn會反比於待測氣體的氣體濃度；當第二電壓V2大於第一電壓V1，則節點電壓Vn會正比於待測氣體的氣體濃度。In this embodiment, the first voltage V1 is different from the second voltage V2. For example, the first voltage V1 and the second voltage V2 may be a system voltage and a ground voltage, respectively. Moreover, one of ordinary skill in the art can select that the first voltage V1 is greater than the second voltage V2, or the second voltage V2 is greater than the first voltage V1. When the first voltage V1 is greater than the second voltage V2, the node voltage Vn is inversely proportional to the gas concentration of the gas to be tested; when the second voltage V2 is greater than the first voltage V1, the node voltage Vn is proportional to the gas concentration of the gas to be tested.
在本發明的實施例中，第一感測元件110及第二感測元件120可以是封裝好的元件，也可以是列印於基板上的電極(或材料)，此依據電路設計而定，本發明實施例不以此為限。In the embodiment of the present invention, the first sensing component 110 and the second sensing component 120 may be encapsulated components, or may be electrodes (or materials) printed on the substrate, depending on the circuit design. The embodiments of the present invention are not limited thereto.
圖2為依據本發明另一實施例的氣體感測器的電路示意圖。請參照圖1及圖2，氣體感測器200大致相同於氣體感測器100，其不同之處在於氣體感測器200的電壓增強電路230，其中相同或相似元件使用相同或相似標號。在本實施例中，電壓增強電路230包括電壓放大器VAMP1。電壓放大器VAMP1的輸入端耦接第一節點N1以接收節點電壓Vn，並且電壓放大器VAMP1的輸出端提供氣體感測電壓VGS，其中電壓放大器VAMP1的放大倍數是大於等於1。當電壓放大器VAMP1的放大倍數等於1，則電壓放大器VAMP1可視為一電壓隨耦器；當電壓放大器VAMP1的放大倍數大於1，則電壓放大器VAMP1會將節點電壓Vn放大後提供氣體感測電壓VGS，亦即氣體感測電壓VGS相對於氣體濃度的變化會加大。2 is a circuit diagram of a gas sensor in accordance with another embodiment of the present invention. 1 and 2, the gas sensor 200 is substantially identical to the gas sensor 100, except that the voltage enhancement circuit 230 of the gas sensor 200, wherein the same or similar elements use the same or similar reference numerals. In the present embodiment, the voltage boosting circuit 230 includes a voltage amplifier VAMP1. The input terminal of the voltage amplifier VAMP1 is coupled to the first node N1 to receive the node voltage Vn, and the output terminal of the voltage amplifier VAMP1 provides the gas sensing voltage VGS, wherein the amplification factor of the voltage amplifier VAMP1 is greater than or equal to 1. When the amplification factor of the voltage amplifier VAMP1 is equal to 1, the voltage amplifier VAMP1 can be regarded as a voltage follower; when the amplification factor of the voltage amplifier VAMP1 is greater than 1, the voltage amplifier VAMP1 amplifies the node voltage Vn to provide the gas sensing voltage VGS, That is, the change in the gas sensing voltage VGS with respect to the gas concentration is increased.
圖3為依據本發明又一實施例的氣體感測器的電路示意圖。請參照圖1及圖3，氣體感測器300大致相同於氣體感測器100，其不同之處在於氣體感測器300的電壓增強電路330，其中相同或相似元件使用相同或相似標號。在本實施例中，電壓增強電路330包括超級二極體DX1、電容C1、電壓隨耦器VF1及差動放大器DAMP1。3 is a circuit diagram of a gas sensor in accordance with still another embodiment of the present invention. Referring to FIGS. 1 and 3, the gas sensor 300 is substantially identical to the gas sensor 100, except that the voltage boosting circuit 330 of the gas sensor 300, wherein the same or similar elements use the same or similar reference numerals. In the present embodiment, the voltage enhancement circuit 330 includes a super diode DX1, a capacitor C1, a voltage follower VF1, and a differential amplifier DAMP1.
超級二極體DX1的輸入端耦接第一節點N1以接收節點電壓Vn。電容C1耦接於超級二極體DX1的輸出端與接地電壓GND之間，以提供參考電壓VR。電壓隨耦器VF1的輸入端耦接電容C1以接收參考電壓VR，電壓隨耦器VF1的輸出端耦接電壓放大器DAMP1的負輸入端。差動放大器DAMP1的正輸入端耦接第一節點N1以接收節點電壓Vn，差動放大器DAMP1的負輸入端耦接電壓隨耦器VF1的輸出端以接收參考電壓VR，並且差動放大器DAMP1的輸出端提供氣體感測電壓VGS。The input end of the super diode DX1 is coupled to the first node N1 to receive the node voltage Vn. The capacitor C1 is coupled between the output terminal of the super diode DX1 and the ground voltage GND to provide a reference voltage VR. The input end of the voltage follower VF1 is coupled to the capacitor C1 to receive the reference voltage VR, and the output end of the voltage follower VF1 is coupled to the negative input terminal of the voltage amplifier DAMP1. The positive input terminal of the differential amplifier DAMP1 is coupled to the first node N1 to receive the node voltage Vn, and the negative input terminal of the differential amplifier DAMP1 is coupled to the output terminal of the voltage follower VF1 to receive the reference voltage VR, and the differential amplifier DAMP1 The output provides a gas sensing voltage VGS.
當氣體感測器300處於一般空氣時，亦即空氣中未具有待測氣體，電容C1會充電到節點電壓Vn可達到的最高電壓。當待測氣體進入空氣中時，由於第一感測元件110及第二感測元件120的阻抗值改變，造成節點電壓Vn的變化，此時超級二極體DX1呈現逆偏截止，因此電容C1的跨壓則維持在上述最高電壓。並且，電容C1所維持的最高電壓與節點電壓Vn的當下電壓準位的差值會藉由差動放大器DAMP1放大後提供氣體感測電壓VGS，亦即可進一步提高氣體訊號的強度。其中，超級二極體DX1用以取代電晶體開關，並且和電容C1組成類似記憶體的電路。When the gas sensor 300 is in a normal air, that is, there is no gas to be tested in the air, the capacitor C1 is charged to the highest voltage achievable by the node voltage Vn. When the gas to be tested enters the air, the impedance of the first sensing element 110 and the second sensing element 120 changes, causing a change in the node voltage Vn. At this time, the super diode DX1 exhibits a reverse bias cutoff, so the capacitor C1 The crossover voltage is maintained at the above maximum voltage. Moreover, the difference between the highest voltage maintained by the capacitor C1 and the current voltage level of the node voltage Vn is amplified by the differential amplifier DAMP1 to provide the gas sensing voltage VGS, which further increases the intensity of the gas signal. Among them, the super diode DX1 is used to replace the transistor switch, and the capacitor C1 constitutes a memory-like circuit.
在本發明的實施例中，由於電壓隨耦器VF1是用以區隔電容C1與差動放大器DAMP1，以降低電容C1的電荷損耗，但在差動放大器DAMP1漏電流極低的情況下，電壓隨耦器VF1可省略而不影響電容C1的跨壓，此可依據電路設計而定，本發明實施例不以此為限。In the embodiment of the present invention, since the voltage follower VF1 is used to separate the capacitor C1 and the differential amplifier DAMP1 to reduce the charge loss of the capacitor C1, in the case where the leakage current of the differential amplifier DAMP1 is extremely low, the voltage The follower VF1 can be omitted without affecting the voltage across the capacitor C1, which can be determined according to the circuit design, and the embodiment of the invention is not limited thereto.
綜上所述，本發明實施例的氣體感測器，其透過串接的正負電阻系數的第一感測元件及第二感測元件，依據氣體濃度推挽第一節點的節點電壓，因此可相對於氣體濃度加大節點電壓的變化幅度，亦即可可提高氣體濃度的感測靈敏度。並且，可透過放大器放大節點電壓，以提高氣體感測電壓的變化幅度，以進一步提高氣體感測器的感測靈敏度。In summary, the gas sensor of the embodiment of the present invention transmits the node voltage of the first node according to the gas concentration through the first sensing element and the second sensing element of the positive and negative resistivity of the series connection, so The sensitivity of the gas concentration can be increased by increasing the magnitude of the change in the node voltage with respect to the gas concentration. Moreover, the node voltage can be amplified by the amplifier to increase the variation range of the gas sensing voltage to further improve the sensing sensitivity of the gas sensor.
雖然本發明已以實施例揭露如上，然其並非用以限定本發明，任何所屬技術領域中具有通常知識者，在不脫離本發明的精神和範圍內，當可作些許的更動與潤飾，故本發明的保護範圍當視後附的申請專利範圍所界定者為準。Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.
100、200、300‧‧‧氣體感測器
110‧‧‧第一感測元件
120‧‧‧第二感測元件
130、230、330‧‧‧電壓增強電路
C1‧‧‧電容
DAMP1‧‧‧差動放大器
DX1‧‧‧超級二極體
GND‧‧‧接地電壓
N1‧‧‧第一節點
V1‧‧‧第一電壓
V2‧‧‧第二電壓
VAMP1‧‧‧電壓放大器
VF1‧‧‧電壓隨耦器
VGS‧‧‧氣體感測電壓
Vn‧‧‧節點電壓
VR‧‧‧參考電壓100, 200, 300‧‧‧ gas sensors
110‧‧‧First sensing element
120‧‧‧Second sensing element
130, 230, 330‧‧‧ voltage boosting circuit
C1‧‧‧ capacitor
DAMP1‧‧‧Differential Amplifier
DX1‧‧‧Super diode
GND‧‧‧ Grounding voltage
N1‧‧‧ first node
V1‧‧‧ first voltage
V2‧‧‧second voltage
VAMP1‧‧‧Voltage Amplifier
VF1‧‧‧ voltage follower
VGS‧‧‧ gas sensing voltage
Vn‧‧‧ node voltage
VR‧‧‧reference voltage
圖1為依據本發明一實施例的氣體感測器的電路示意圖。 圖2為依據本發明另一實施例的氣體感測器的電路示意圖。 圖3為依據本發明又一實施例的氣體感測器的電路示意圖。1 is a circuit diagram of a gas sensor in accordance with an embodiment of the present invention. 2 is a circuit diagram of a gas sensor in accordance with another embodiment of the present invention. 3 is a circuit diagram of a gas sensor in accordance with still another embodiment of the present invention.
100‧‧‧氣體感測器 100‧‧‧ gas sensor
110‧‧‧第一感測元件 110‧‧‧First sensing element
120‧‧‧第二感測元件 120‧‧‧Second sensing element
130‧‧‧電壓增強電路 130‧‧‧Voltage Enhancement Circuit
N1‧‧‧第一節點 N1‧‧‧ first node
V1‧‧‧第一電壓 V1‧‧‧ first voltage
V2‧‧‧第二電壓 V2‧‧‧second voltage
VGS‧‧‧氣體感測電壓 VGS‧‧‧ gas sensing voltage
Vn‧‧‧節點電壓 Vn‧‧‧ node voltage
Claims (7)
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| TW105119664A TWI571631B (en) | 2016-06-23 | 2016-06-23 | Gas sensor |
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| TW105119664A TWI571631B (en) | 2016-06-23 | 2016-06-23 | Gas sensor |
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| TWI571631B true TWI571631B (en) | 2017-02-21 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030042152A1 (en) * | 2001-09-05 | 2003-03-06 | Keigo Mizutani | Gas sensor and method of detecting gas concentration |
| CN1755355A (en) * | 2004-09-28 | 2006-04-05 | Tdk株式会社 | Gas concentration measurement method gas sensor |
| US20100107735A1 (en) * | 2005-09-22 | 2010-05-06 | Igor Pavlovsky | Gas Sensor |
| CN201976074U (en) * | 2011-03-01 | 2011-09-14 | 深圳市联祥瑞智能设备有限公司 | Amplification circuit of gas sensor |
| CN203688490U (en) * | 2013-12-20 | 2014-07-02 | 联想(北京)有限公司 | Corrosion gas detection device and computer |
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2016
- 2016-06-23 TW TW105119664A patent/TWI571631B/en active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030042152A1 (en) * | 2001-09-05 | 2003-03-06 | Keigo Mizutani | Gas sensor and method of detecting gas concentration |
| CN1755355A (en) * | 2004-09-28 | 2006-04-05 | Tdk株式会社 | Gas concentration measurement method gas sensor |
| US20100107735A1 (en) * | 2005-09-22 | 2010-05-06 | Igor Pavlovsky | Gas Sensor |
| TW201135225A (en) * | 2010-01-11 | 2011-10-16 | Applied Nanotech Holdings Inc | Gas sensor |
| CN201976074U (en) * | 2011-03-01 | 2011-09-14 | 深圳市联祥瑞智能设备有限公司 | Amplification circuit of gas sensor |
| CN203688490U (en) * | 2013-12-20 | 2014-07-02 | 联想(北京)有限公司 | Corrosion gas detection device and computer |
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| TW201800748A (en) | 2018-01-01 |
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